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Sample records for chromatid exchange induced

  1. Detection of sister chromatid exchanges induced by volatile genotoxicants

    SciTech Connect

    Tucker, J.D.; Xu, J.; Stewart, J.; Baciu, P.C.; Ong, T.M.

    1986-01-01

    To test the recently developed method of exposing cells to volatile compounds, phytohemagglutinin-stimulated human peripheral lymphocyte cultures were exposed to gaseous methyl bromide, ethylene oxide, and propylene oxide, as well as diesel exhaust. The cultures were placed in sterile dialysis tubing and inserted into enclosed flasks containing additional culture medium. The test compounds (in gaseous state) were diluted with air and bubbled through the flasks for various lengths of time. The cells were then washed and incubated for a total of 75 h. The harvest was performed according to established procedures, and second-division cells were scored for induction of sister chromatid exchanges (SCEs). The SCE frequency was more than doubled in the cultures treated with ethylene oxide and propylene oxide; methyl bromide also induced SCEs. Cultures treated with diesel exhaust showed an increase in the SCE frequency in cells from two of four donors tested. These results further substantiate the use of this method for detecting the induction of SCEs by airborne genotoxins.

  2. Mutagenicity, sister chromatid exchange inducibility and in vitro cell transforming ability of particulates from Athens air

    SciTech Connect

    Athanasiou, K.; Arzimanoglou, I.; Piccoli, C.; Yamasaki, H.

    1987-09-01

    Airborne particulates were collected over a period of twelve months by the use of Hi-Vol samplers in the basin of Athens, Greece. N-Hexane extracts were tested in a battery of in vitro tests for their ability to induce mutation in bacteria as well as mutations, sister chromatid exchange and morphological transformation in cultured mammalian cells. Positive results were found for mutagenicity with Salmonella strain TA98 in the Ames assay, for sister chromatid exchange induction in CHO cells and for transformation in BALB/c 3T3 cells in culture. They also showed weak non-dose-related induction of ouabain resistance in BALB/c 3T3 cells. The contribution of oxidizing and nitrating agents found in the Athens atmosphere, together with sunlight UV irradiation in the formation of direct acting mutagens and potential carcinogens from ambient polycyclic aromatic hydrocarbons, is suggested.

  3. Sister chromatid exchange in human lymphocytes induced by propoxur following plant activation by Vicia faba.

    PubMed

    Gómez-Arroyo, S; Calderón-Segura, M E; Villalobos-Pietrini, R

    1995-01-01

    Because the carbamate insecticide propoxur induced sister chromatid exchanges (SCE) in Vicia faba but was ineffective in producing SCE in lymphocytes in culture, it was hardly suspected that plant metabolism was involved. Experiments were conducted in which metabolic activation was afforded by Vicia faba roots, and SCE in human lymphocytes in vitro was used to assess cytogenetic damage. Several concentrations of propoxur (250, 500, 1,000, 1,500, and 2,000 ppm) were applied for 4 hr to the roots of Vicia faba. Extracts prepared from these treatments were added to the lymphocyte cultures and a significant increase of SCE frequencies with a concentration-response relationship could be detected. The lymphocyte proliferation kinetics and the proliferation rate index (PRI) were not affected (except in the highest concentration, of 2,000 ppm). This general behavior was in agreement with the presence of an enzymatic system (S10 fraction) in Vicia roots capable of metabolizing or activating the propoxur. With 2,000 ppm, cell necrosis was produced in Vicia; therefore, this extract did not induce SCE in lymphocytes. However, lymphocyte proliferation kinetics were delayed and PRI was significantly decreased. Ethanol, a promutagen activated by this plant, was applied directly to the lymphocyte cultures as a positive control, and the response was negative. On the other hand, the extracts of roots treated with ethanol increased the SCE to more than twice that of the negative control, but the lymphocyte proliferation kinetics and PRI were not affected.

  4. Occurrence in vivo of sister chromatid exchanges at the same locus in successive cell divisions caused by nonrepairable lesions induced by gamma rays

    SciTech Connect

    Morales-Ramirez, P.; Vallarino-Kelly, T.; Rodriguez-Reyes, R.

    1988-01-01

    The capacity of lesions induced by gamma radiation to produce sister chromatid exchanges (SCE) in successive divisions in mouse bone marrow cells in vivo was evaluated using a protocol for the three-way differentiation of sister chromatids. Evidence was obtained that exposure to gamma radiation induces DNA lesions that result in the formation of SCE at the same locus in two successive cell divisions. The relevance of this observation with respect to DNA repair and mutagenesis is discussed.

  5. Baseline and sodium arsenite-induced sister chromatid exchanges in cultured lymphocytes from patients with Blackfoot disease and healthy persons.

    PubMed

    Wen, W N; Lieu, T L; Chang, H J; Wuu, S W; Yau, M L; Jan, K Y

    1981-01-01

    A significantly higher frequency of baseline sister chromatid exchange (SCE) was found in the cultured lymphocytes of 13 Blackfoot disease patients (BFP) in comparison with that of healthy persons (HP). Twelve of these BFP consumed well water containing a high concentration of arsenic for 15 years or longer and had switched to drinking tap water 12 years before the time of this study. Sodium arsenite was found to be effective in increasing the SCE frequency and delaying the cell growth of the lymphocytes from both BFP and HP. However, the SCE increment induced by sodium arsenite as well as the progression of the cell divisions in the cultured lymphocytes showed no significant difference between BFP and HP.

  6. How-to-Do-It: Demonstrating Sister Chromatid Exchanges.

    ERIC Educational Resources Information Center

    Dye, Frank J.

    1988-01-01

    Outlines procedures for demonstrating and preparing a permanent slide of sister chromatid exchanges and recombination events between the two chromatids of a single chromosome. Provides the name of an additional resource for making preparations of exchanges. (RT)

  7. Influence of retinol on carcinogen-induced sister chromatid exchangers and chromosome aberrations in V79 cells

    SciTech Connect

    Qin, S.; Batt, T.; Huang, C.C.

    1985-01-01

    The influence of retinol (Rol) on sister chromatid exchangers (SCE) in V79 cells induced by six indirect and two direct carcinogens, and on chromosome aberration (CA) in V79 cells induced by four indirect carcinogens were studied. The indirect carcinogens used were aflatoxin B/sub 1/ (AFB), cyclophosphamide (CPP), benzo(a)anthracene (BA), benzo(a)pyrene (BP), 9,10-dimethyl-1,2-benz(a)anthracene (DMBA), and 3-methylcholanthrene (MCA). The two direct carcinogens were ethyl methane sulfonate (EMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Rol effectively inhibited SCE and CA induced by AFB and CPP in a dose-dependent manner, but it had no effect on SCE induced by BA, BP, DMBA, MCA, EMS, and MNNG. To the contrary, Rol had an enhancing effect on CA induced by BP and DMBA. The possibility that Rol exerts its anticarcinogenic effects by inhibiting certain forms of the cytochrome P-450 isoenzymes required for activation of precarcinogens, such as AFB and CPP but not those enzymes required by BA, BP, DMBA, and MCA, is discussed.

  8. The association between frequencies of mitomycin C-induced sister chromatid exchange and cancer risk in arseniasis.

    PubMed

    Liou, Saou-Hsing; Chen, Yeong-Hwang; Loh, Ching-Hui; Yang, Tsan; Wu, Trong-Neng; Chen, Chien-Jen; Hsieh, Ling-Ling

    2002-03-28

    In order to examine whether biomarkers of cytogenetic damage and susceptibility, such as spontaneous and mitomycin C-induced sister chromatid exchange (SCE) can predict cancer development, a nested case-control study was performed in a blackfoot endemic area with known high cancer risk. A cohort of 686 residents was recruited from three villages in the arseniasis area. Personal characteristics were collected and venous blood was drawn for lymphocyte culture and stored in a refrigerator. The vital status and cancer development was followed using the National Death Registry, Cancer Registry, and Blackfoot Disease Registry. The follow up period was from August 1991 to July 1997. During this 6-year-period, 55 residents developed various types of cancer. Blood culture samples from 23 of these subjects were unsuitable for spontaneous SCE experiments and 45 of these subjects were unsuitable for mitomycin C-induced SCE experiments due to improper storage. Finally, a total of 32 cancer cases had cytogenetic samples that could be analyzed. About 32 control subjects were selected from those who did not develop cancer in the study period and these subjects were matched to cases by sex, age, smoking habits, and residential area. The results showed that there was no significant difference in the frequencies of spontaneous and mitomycin C-induced SCE between the case and control groups. There was also no significant difference in the net difference of spontaneous and mitomycin C-induced SCE between the case and control groups. These results suggest that SCEs, either spontaneous or mitomycin C-induced, might not be good markers to predict cancer risk.

  9. Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination

    SciTech Connect

    Nagasawa, H; Wilson, P F; Chen, D J; Thompson, L H; Bedford, J S; Little, J B

    2007-10-26

    We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a prominent bystander effect observed in V79 cells (Nagasawa et al., Radiat. Res. 164, 141-147, 2005). In the present study, we examined additional Chinese hamster cell lines deficient in the Rad51 paralogs Rad51C, Rad51D, Xrcc2, and Xrcc3 as well as another essential HRR protein, Brca2. Spontaneous SCE frequencies in non-irradiated wild-type cell lines CHO, AA8 and V79 were 0.33 SCE/chromosome, whereas two Rad51C-deficient cell lines showed only 0.16 SCE/chromosome. Spontaneous SCE frequencies in cell lines defective in Rad51D, Xrcc2, Xrcc3, and Brca2 ranged from 0.23-0.33 SCE/chromosome, 0-30% lower than wild-type cells. SCEs were induced significantly 20-50% above spontaneous levels in wild-type cells exposed to a mean dose of 1.3 mGy of alpha particles (<1% of nuclei traversed by an alpha particle). However, induction of SCEs above spontaneous levels was minimal or absent after {alpha}-particle irradiation in all of the HRR-deficient cell lines. These data suggest that Brca2 and the Rad51 paralogs contribute to DNA damage repair processes induced in bystander cells (presumably oxidative damage repair in S-phase cells) following irradiation with very low doses of alpha particles.

  10. Metabolism, sister chromatid exchanges, and DNA single-strand breaks induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and their modulation by vitamin A in vitro.

    PubMed

    Alaoui-Jamali, M A; Bélanger, P M; Rossignol, G; Castonguay, A

    1991-08-01

    The nicotine-derived N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanone (NNK) is abundant in smokeless tobacco and tobacco smoke and is hepatocarcinogenic in F344 rats. We have investigated how vitamin A modulates sister chromatid exchanges and DNA single-strand breaks induced by NNK. In V79 cells, vitamin A at concentrations ranging from 34.9 to 139.6 microM inhibited sister chromatid exchange frequencies induced by 20 mM NNK activated by primary rat hepatocytes. Sister chromatid exchanges were inhibited by 24, 44, and 55% when cells were cotreated with 34.9, 69.8, and 139.6 microM vitamin A, respectively. DNA single-strand breaks induced by NNK in rat hepatocytes were also inhibited by vitamin A. After 9 h of elution, DNA single-strand breaks induced by 1, 5, and 10 mM NNK were inhibited by 13, 5, and 3.5% in the presence of 69.8 microM vitamin A, respectively. This protective effect by vitamin A was associated with a reduction of alpha-carbon hydroxylation, an activation pathway of NNK. This pathway was inhibited by 50% when cells were cotreated with 3.49 microM vitamin A. The reduction in the hepatic microsomal aminopyrine N-demethylase, aniline hydroxylase, and N,N-dimethyl aniline N-demethylase in the presence of vitamin A (0.035 to 0.35 microM) suggests that vitamin A could reduce NNK genotoxicity by inhibiting the enzymes involved in the activation process. PMID:1855212

  11. Histone H3 K79 methylation states play distinct roles in UV-induced sister chromatid exchange and cell cycle checkpoint arrest in Saccharomyces cerevisiae

    PubMed Central

    Rossodivita, Alyssa A.; Boudoures, Anna L.; Mecoli, Jonathan P.; Steenkiste, Elizabeth M.; Karl, Andrea L.; Vines, Eudora M.; Cole, Arron M.; Ansbro, Megan R.; Thompson, Jeffrey S.

    2014-01-01

    Histone post-translational modifications have been shown to contribute to DNA damage repair. Prior studies have suggested that specific H3K79 methylation states play distinct roles in the response to UV-induced DNA damage. To evaluate these observations, we examined the effect of altered H3K79 methylation patterns on UV-induced G1/S checkpoint response and sister chromatid exchange (SCE). We found that the di- and trimethylated states both contribute to activation of the G1/S checkpoint to varying degrees, depending on the synchronization method, although methylation is not required for checkpoint in response to high levels of UV damage. In contrast, UV-induced SCE is largely a product of the trimethylated state, which influences the usage of gene conversion versus popout mechanisms. Regulation of H3K79 methylation by H2BK123 ubiquitylation is important for both checkpoint function and SCE. H3K79 methylation is not required for the repair of double-stranded breaks caused by transient HO endonuclease expression, but does play a modest role in survival from continuous exposure. The overall results provide evidence for the participation of H3K79 methylation in UV-induced recombination repair and checkpoint activation, and further indicate that the di- and trimethylation states play distinct roles in these DNA damage response pathways. PMID:24748660

  12. SISTER-CHROMATID EXCHANGE IN 4 HUMAN RACES

    PubMed Central

    BUTLER, MERLIN G.

    2016-01-01

    SUMMARY The frequencies of sister-chromatid exchanges (SCE) were investigated in lymphocytes in 32 normal adult individuals of both sexes with no interracial familial backgrounds from Caucasian, American black, oriental and native American races. There was no significant difference in the average frequency of SCEs in the 4 races. PMID:7266577

  13. Vanadium suppresses sister-chromatid exchange and DNA-protein crosslink formation and restores antioxidant status and hepatocellular architecture during 2-acetylaminofluorene-induced experimental rat hepatocarcinogenesis.

    PubMed

    Chakraborty, Tridib; Ghosh, Shilpi; Datta, Subroto; Chakraborty, Prabir; Chatterjee, Malay

    2003-01-01

    Vanadium is an important regulator of cellular growth, differentiation, and cell death, and thus has received increasing attention to be an effective cancer chemopreventive agent. In the present study, attempts have been made to investigate the in vivo antineoplastic effect of this micronutrient at the 0.5 ppm dosage in drinking water, by monitoring hepatic nodulogenesis and hepatocellular phenotype followed by antioxidant status and atomic absorption spectrometric estimation of some essential biometals during the multistage of carcinogenesis induced by 2-acetylaminofluorene (2-AAF; 0.05% in basal diet). Finally, sister-chromatid exchange (SCE) and DNA-protein crosslink (DPC) formation, as potential biomarkers were estimated to find out the suppressive effect of vanadium at the molecular level. The results showed that vanadium administration throughout the experiment reduced the relative liver weight, nodular incidence (48.40%), total number, and multiplicity (63.91%), and altered the size of visible persistent nodules (PNs) with concurrent restoration of hepatic glutathione (P < 0.01), glutathione-S-transferase (P < 0.001) and manganese-dependent superoxide dismutase (P < 0.001) activities as well as, hepatic zinc and copper contents (P < 0.001) when compared to the carcinogen control. Moreover, vanadium treatment significantly reduced SCE frequency (50.24%) and DPC coefficient (P < 0.001; 21.30%). Our results, thus, strongly suggest that supplementary vanadium at a dose of 0.5 ppm, when administered continuously throughout the study, than administered either in the initiation or promotion phase alone, is very much effective in suppressing neoplastic transformation during 2-AAF-induced in vivo rat hepatocarcinogenesis.

  14. Effect of borax on immune cell proliferation and sister chromatid exchange in human chromosomes

    PubMed Central

    Pongsavee, Malinee

    2009-01-01

    Background Borax is used as a food additive. It becomes toxic when accumulated in the body. It causes vomiting, fatigue and renal failure. Methods The heparinized blood samples from 40 healthy men were studied for the impact of borax toxicity on immune cell proliferation (lymphocyte proliferation) and sister chromatid exchange in human chromosomes. The MTT assay and Sister Chromatid Exchange (SCE) technic were used in this experiment with the borax concentrations of 0.1, 0.15, 0.2, 0.3 and 0.6 mg/ml. Results It showed that the immune cell proliferation (lymphocyte proliferation) was decreased when the concentrations of borax increased. The borax concentration of 0.6 mg/ml had the most effectiveness to the lymphocyte proliferation and had the highest cytotoxicity index (CI). The borax concentrations of 0.15, 0.2, 0.3 and 0.6 mg/ml significantly induced sister chromatid exchange in human chromosomes (P < 0.05). Conclusion Borax had effects on immune cell proliferation (lymphocyte proliferation) and induced sister chromatid exchange in human chromosomes. Toxicity of borax may lead to cellular toxicity and genetic defect in human. PMID:19878537

  15. Solution Radioactivated by Hadron Radiation Can Increase Sister Chromatid Exchanges

    PubMed Central

    Maeda, Junko; Yurkon, Charles R.; Fujii, Yoshihiro; Fujisawa, Hiroshi; Kato, Sayaka; Brents, Colleen A.; Uesaka, Mitsuru; Fujimori, Akira; Kitamura, Hisashi; Kato, Takamitsu A.

    2015-01-01

    When energetic particles irradiate matter, it becomes activated by nuclear reactions. Radioactivation induced cellular effects are not clearly understood, but it could be a part of bystander effects. This investigation is aimed at understanding the biological effects from radioactivation in solution induced by hadron radiation. Water or phosphate buffered saline was activated by being exposed to hadron radiation including protons, carbon- and iron-ions. 1 mL of radioactivated solution was transferred to flasks with Chinese hamster ovary (CHO) cells cultured in 5 mL of complete media. The induction of sister chromatid exchanges (SCE) was used to observe any increase in DNA damage responses. The energy spectrum and the half-lives of the radioactivation were analyzed by NaI scintillation detector in order to identify generated radionuclides. In the radioactivated solution, 511 keV gamma-rays were observed, and their half-lives were approximately 2 min, 10 min, and 20 min. They respectively correspond to the beta+ decay of 15O, 13N, and 11C. The SCE frequencies in CHO cells increased depending on the amount of radioactivation in the solution. These were suppressed with a 2-hour delayed solution transfer or pretreatment with dimethyl sulfoxide (DMSO). Our results suggest that the SCE induction by radioactivated solution was mediated by free radicals produced by the annihilated gamma-rays. Since the SCE induction and DMSO modulation are also reported in radiation-induced bystander effects, our results imply that radioactivation of the solution may have some contribution to the bystander effects from hadron radiation. Further investigations are required to assess if radioactivation effects would attribute an additional level of cancer risk of the hadron radiation therapy itself. PMID:26657140

  16. Solution Radioactivated by Hadron Radiation Can Increase Sister Chromatid Exchanges.

    PubMed

    Maeda, Junko; Yurkon, Charles R; Fujii, Yoshihiro; Fujisawa, Hiroshi; Kato, Sayaka; Brents, Colleen A; Uesaka, Mitsuru; Fujimori, Akira; Kitamura, Hisashi; Kato, Takamitsu A

    2015-01-01

    When energetic particles irradiate matter, it becomes activated by nuclear reactions. Radioactivation induced cellular effects are not clearly understood, but it could be a part of bystander effects. This investigation is aimed at understanding the biological effects from radioactivation in solution induced by hadron radiation. Water or phosphate buffered saline was activated by being exposed to hadron radiation including protons, carbon- and iron-ions. 1 mL of radioactivated solution was transferred to flasks with Chinese hamster ovary (CHO) cells cultured in 5 mL of complete media. The induction of sister chromatid exchanges (SCE) was used to observe any increase in DNA damage responses. The energy spectrum and the half-lives of the radioactivation were analyzed by NaI scintillation detector in order to identify generated radionuclides. In the radioactivated solution, 511 keV gamma-rays were observed, and their half-lives were approximately 2 min, 10 min, and 20 min. They respectively correspond to the beta+ decay of 15O, 13N, and 11C. The SCE frequencies in CHO cells increased depending on the amount of radioactivation in the solution. These were suppressed with a 2-hour delayed solution transfer or pretreatment with dimethyl sulfoxide (DMSO). Our results suggest that the SCE induction by radioactivated solution was mediated by free radicals produced by the annihilated gamma-rays. Since the SCE induction and DMSO modulation are also reported in radiation-induced bystander effects, our results imply that radioactivation of the solution may have some contribution to the bystander effects from hadron radiation. Further investigations are required to assess if radioactivation effects would attribute an additional level of cancer risk of the hadron radiation therapy itself. PMID:26657140

  17. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... references should be consulted. (1) 40 CFR 798.5915, In vivo Sister Chromatid Exchange Assay. (2) Kato, H...) assay detects the ability of a chemical to enhance the exchange of DNA between two sister chromatids of... ligation of at least two DNA helices. (c) Test method—(1) Principle of the test method. (i) Groups...

  18. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... references should be consulted. (1) 40 CFR 798.5915, In vivo Sister Chromatid Exchange Assay. (2) Kato, H...) assay detects the ability of a chemical to enhance the exchange of DNA between two sister chromatids of... ligation of at least two DNA helices. (c) Test method—(1) Principle of the test method. (i) Groups...

  19. Telomere sister chromatid exchange in telomerase deficient murine cells

    SciTech Connect

    Wang, Yisong; Giannone, Richard J; Liu, Yie

    2005-01-01

    We have recently demonstrated that several types of genomic rearrangements (i.e., telomere sister chromatid exchange (T-SCE), genomic-SCE, or end-to-end fusions) were more often detected in long-term cultured murine telomerase deficient embryonic stem (ES) cells than in freshly prepared murine splenocytes, even through they possessed similar frequencies of critically short telomeres. The high rate of genomic rearrangements in telomerase deficient ES cells, when compared to murine splenocytes, may reflect the cultured cells' gained ability to protect chromosome ends with eroded telomeres allowing them to escape 'end crisis'. However, the possibility that ES cells were more permissive to genomic rearrangements than other cell types or that differences in the microenvironment or genetic background of the animals might consequentially determine the rate of T-SCEs or other genomic rearrangements at critically short telomeres could not be ruled out.

  20. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... references should be consulted. (1) 40 CFR 798.5915, In vivo Sister Chromatid Exchange Assay. (2) Kato, H.... (6) Kligerman, A., et al., “Cytogenetic Studies of Mice Exposed to Styrene by Inhalation.”,...

  1. Induction of sister chromatid exchanges by coal dust and tobacco snuff extracts in human peripheral lymphocytes

    SciTech Connect

    Tucker, J.D.; Ong, T.

    1985-01-01

    The organic solvent extracts of sub-bituminous coal dust and tobacco snuff, both together and separately, were tested for the induction of sister chromatid exchanges (SCEs) in human peripheral lymphocytes. The results indicate that these extracts induced SCEs, and that when tested together synergistically induced SCEs in two of three donors. Studies with the organic solvent extracts of all five ranks of coal indicate that the extracts of bituminous, lignite, and peat, but not anthracite, induced SCEs. Similar experiments conducted with water extracts, induced SCEs, and that anthracite was equivocal. To determine whether individuals differed in their SCE responses to coal dust extracts, lymphocytes from five donors were tested with organic solvent extracts of bituminous and sub-bituminous coal. An analysis of variance indicates that the SCE response was significantly influenced by the donor and each of the two coal extracts. The findings presented here suggest that coal dust, with or without tobacco snuff, may play a role in the elevated incidence of gastric cancer in coal miners. Because water extracts of some ranks of coal induced SCEs, there exists the possibility of adverse environmental effects due to coal leachates.

  2. Chromosome aberrations and sister chromatid exchanges in cultured human lymphocytes treated with sodium metabisulfite, a food preservative.

    PubMed

    Rencüzogullari, E; Ila, H B; Kayraldiz, A; Topaktaş, M

    2001-02-20

    The aim of this study was to investigate the ability of sodium metabisulfite (SMB) which is used as an antimicrobial substance in food, to induce chromosome aberrations (CA) and sister chromatid exchanges (SCE) in human lymphocytes. SMB-induced CAs and SCEs at all concentrations (75, 150 and 300 microg/ml) and treatment periods (24 and 48h) dose-dependently. However, SMB decreased the replication index (RI) and the mitotic index (MI) at the concentrations of 150 and 300 microg/ml for 24 and 48h treatment periods. This decrease was dose-dependent as well.

  3. Activity of nitro-polynuclear aromatic hydrocarbons in the sister chromatid exchange assay with and without metabolic activation.

    PubMed

    Nachtman, J P; Wolff, S

    1982-01-01

    Nitro-polynuclear aromatic hydrocarbons are found in diesel particulates. These compounds are potent mutagens in the Ames test. To determine whether nitro-polynuclear aromatic hydrocarbons are active in a mammalian cell assay, 1-nitropyrene, 1,8-dinitropyrene, 2-nitrofluorene, and 4-nitrobiphenyl were incubated with cultures of Chinese hamster ovary cells. The frequency of sister chromatid exchange (SCE) was measured in the presence and absence of rat liver S-9 mix. The addition of S-9 mix resulted in a large increase in the SCEs induced by all four compounds. PMID:7067667

  4. The relationship between sister chromatid exchanges and chromosome aberrations in Bloom's syndrome.

    PubMed

    Shiraishi, Y; Sandberg, A A

    1977-01-01

    The distribution of the break points of sister chromatid exchanges (SCE) was compared with that of chromosome aberrations in Bloom's syndrome by using differential sister chromatid staining and banding techniques. A comparison was made of the distribution in chromosomes 1, 2, and 3, since the exact identification of other chromosomes is difficult with the differential sister-chromatid staining technique. It was shown that SCE and chromosome breaks do not necessarily correlate as to location. Some chromosome break points, e.g., 1q21, 1p36, 2q31, 3q12, and 3p13, were common with those of SCE, whereas others (at 1p13, 2p11, 2q11, and 3q11) showed little or no SCE. SCE breaks were not observed in the centromeric regions. In addition, the SCE frequency was examined in Bloom's syndrome cells with and without chromosome aberrations, and no significant differences of SCE frequency were observed between cells with chromatid- or chromosome-type of aberrations and those with normal complements. Banding analyses indicated a nonrandom distribution of chromosome breaks in the lymphocytes and marrow cells of the Bloom's syndrome patient.

  5. Induction of sister chromatid exchanges and bacterial revertants by organic extracts of airborne particles. [Humans

    SciTech Connect

    Lockard, J.M.; Viau, C.J.; Lee-Stephens, C.; Caldwell, J.C.; Wojciechowski, J.P.; Enoch, H.G.; Sabharwal, P.S.

    1981-01-01

    The genotoxicities of organic extracts of airborne particles have been studied extensively in the Salmonella/mammalian microsome (Ames) test, but in few other bioassays. In these studies, we tested benzene-acetone extracts of particulate pollutants collected in Lexington, Kentucky, for capacity to induce increases in sister chromatid exchanges (SCE) in human lumphocytes and V79 cells, as well as in the Ames assay. Extracts induced linear dose-related increases in SCE in human lumphocytes and in bacterial revertants.However, variable responses were observed in SCE assays in V79 cells with and without activation by rat liver S9 or feeder layers of irradiated Syrian hamster fetal cells. We conclude that the SCE assay in human lumphocytes may be a useful indicator of the potential risks to humans of airborne particulate pollutants, as it utilizes human cells recently taken from the host, is rapid and economical, and requires small quantities of test materials. However, thorough studies of the quantitative relationships between SCE induction and mutagenicity in human cells are needed.

  6. Evaluation of genotoxic effects of Apitol (cymiazole hydrochloride) in vitro by measurement of sister chromatid exchange.

    PubMed

    Stanimirovic, Zoran; Stevanovic, Jevrosima; Jovanovic, Slobodan; Andjelkovic, Marko

    2005-12-30

    Apitol, with cymiazole hydrochloride as the active ingredient, is used in bee-keeping against the ectoparasitic mite Varroa destructor. The preparation was evaluated for genotoxicity in cultured human peripheral blood lymphocytes. Sister chromatid exchange, the mitotic index and the cell proliferation index were determined for three experimental concentrations of Apitol (0.001, 0.01 and 0.1 mg/ml). All concentrations significantly (p < 0.001) increased the mitotic index (MI = 7.35+/-0.18%, 8.31+/-0.20% and 12.33+/-0.25%, respectively), the proliferative index (PI = 1.83+/-0.01, 1.84+/-0.01 and 1.88+/-0.02, respectively) and the frequency of sister chromatid exchange (SCE = 8.19+/-1.81, 8.78+/-1.80 and 13.46+/-1.88, respectively), suggesting that cymiazole hydrochloride has genotoxic potential. PMID:16309949

  7. Evaluation of genotoxic effects of Apitol (cymiazole hydrochloride) in vitro by measurement of sister chromatid exchange.

    PubMed

    Stanimirovic, Zoran; Stevanovic, Jevrosima; Jovanovic, Slobodan; Andjelkovic, Marko

    2005-12-30

    Apitol, with cymiazole hydrochloride as the active ingredient, is used in bee-keeping against the ectoparasitic mite Varroa destructor. The preparation was evaluated for genotoxicity in cultured human peripheral blood lymphocytes. Sister chromatid exchange, the mitotic index and the cell proliferation index were determined for three experimental concentrations of Apitol (0.001, 0.01 and 0.1 mg/ml). All concentrations significantly (p < 0.001) increased the mitotic index (MI = 7.35+/-0.18%, 8.31+/-0.20% and 12.33+/-0.25%, respectively), the proliferative index (PI = 1.83+/-0.01, 1.84+/-0.01 and 1.88+/-0.02, respectively) and the frequency of sister chromatid exchange (SCE = 8.19+/-1.81, 8.78+/-1.80 and 13.46+/-1.88, respectively), suggesting that cymiazole hydrochloride has genotoxic potential.

  8. Sister chromatid exchange data fit with a mixture of Poisson distributions.

    PubMed

    Byers, R H; Shenton, L R

    1999-06-30

    Bowman et al. [K.O. Bowman, Wesley Eddings, Marvin A. Kastenbaum, L. R. Shenton. Sister chromatid exchange data and Gram-Charlier series, Mutat. Res., 403 (1998) 159-169.] have shown that a Gram-Charlier modification of a negative binomial distribution gives a reasonable fit to counts of sister chromatid exchange (SCE) data originally presented by Bender et al. [M.A. Bender, R.J. Preston, R. C. Leonard, B.E. Pyatt, P.C. Gooch, On the distribution of spontaneous SCE in human peripheral blood lymphocytes, Mutat. Res., 281 (1992) 227-232. ]. Here we show that a mixture of a generalized Poisson distributions also fits the data. Advantages of the generalized Poisson mixture include a simplified model involving only four parameters which fits the data more closely according to the chi-squared goodness-of-fit criterion. PMID:10393269

  9. Sister chromatid exchange analysis to monitor genotoxic chemicals. (Latest citations from Pollution Abstracts). Published Search

    SciTech Connect

    Not Available

    1993-03-01

    The bibliography contains citations concerning the use of the sister chromatid exchange (SCE) analysis for toxicological studies. SCE analysis are very sensitive measures of genotoxic damage to chromosomes. SCE toxicological studies analyzing ionizing radiation, chromium compounds, styrene, paint thinner, mercury, cigarette smoke, coal dust, fuel oil, insecticides, ethylene oxide, diesel exhaust, and polychlorinated biphenyls are discussed. SCE studies using both human and animal tissue cultures are described. (Contains a minimum of 191 citations and includes a subject term index and title list.)

  10. Induction of sister-chromatid exchanges in Chinese hamster ovary cells by the biotic ketoaldehyde methylglyoxal.

    PubMed

    Faggin, P; Bassi, A M; Finollo, R; Brambilla, G

    1985-11-01

    The number of sister-chromatid exchanges (SCEs) per metaphase was determined in Chinese hamster ovary cells after 16 h exposure to methylglyoxal (MG) concentrations ranging from 0.1 to 0.75 mM. MG produced an increase of SCE frequency that proved to be dose-dependent, and to reach a maximum of 2 X baseline at the highest nontoxic concentration (0.5 mM).

  11. [Sister chromatid exchanges and chromosome aberrations as parameters for human risk of cancer development].

    PubMed

    Morimoto, K

    1987-04-01

    Chromosome alterations, which are directly visible changes in the DNA, have close associations to cancer development, non-specific ageing, and heritable genetic status. Human lymphocyte cultures can be used for cytogenetic monitoring of genetic health because many cancers and genetic effects are caused by long-term unhealthy life-styles. We have investigated the sensitivities of lymphocytes from inherited-cancer-prone diseases to the induction of the chromosome alterations by mutagens and carcinogens, and the correlations between the frequency of sister chromatid exchanges (SCEs) in peripheral lymphocytes and life-styles or daily ways of living. Lymphocytes from patients with Down syndrome, Fanconi anemia, xeroderma pigmentosum, ataxia telangiectasia, and Bloom syndromes showed altered (usually enhanced) susceptibilities to the induction of chromosome aberrations and SCEs by mutagens and carcinogens in our environments. Mean frequencies of baseline SCEs in lymphocytes from normal men with poor life-styles have also been shown to be significantly higher than those in cells from men having good life-styles. The former cells have further been shown to have hyper sensitivities to the induction of SCEs by mitomycin-C' treatment compared to latter cells. Unhealthy life-styles also make the lymphocytes to be more sensitive to ara-C's enhancement of radiation-induced chromosome aberrations.

  12. Health assessment of gasoline and fuel oxygenate vapors: micronucleus and sister chromatid exchange evaluations.

    PubMed

    Schreiner, Ceinwen A; Hoffman, Gary M; Gudi, Ramadevi; Clark, Charles R

    2014-11-01

    Micronucleus and sister chromatid exchange (SCE) tests were performed for vapor condensate of baseline gasoline (BGVC), or gasoline with oxygenates, methyl tert-butyl ether (G/MTBE), ethyl tert butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), t-butyl alcohol (TBA), or ethanol (G/EtOH). Sprague Dawley rats (the same 5/sex/group for both endpoints) were exposed to 0, 2000, 10,000, or 20,000mg/m(3) of each condensate, 6h/day, 5days/week over 4weeks. Positive controls (5/sex/test) were given cyclophosphamide IP, 24h prior to sacrifice at 5mg/kg (SCE test) and 40mg/kg (micronucleus test). Blood was collected from the abdominal aorta for the SCE test and femurs removed for the micronucleus test. Blood cell cultures were treated with 5μg/ml bromodeoxyuridine (BrdU) for SCE evaluation. No significant increases in micronucleated immature erythrocytes were observed for any test material. Statistically significant increases in SCE were observed in rats given BGVC alone or in female rats given G/MTBE. G/TAME induced increased SCE in both sexes at the highest dose only. Although DNA perturbation was observed for several samples, DNA damage was not expressed as increased micronuclei in bone marrow cells. Inclusion of oxygenates in gasoline did not increase the effects of gasoline alone or produce a cytogenetic hazard. PMID:24852491

  13. Health assessment of gasoline and fuel oxygenate vapors: micronucleus and sister chromatid exchange evaluations.

    PubMed

    Schreiner, Ceinwen A; Hoffman, Gary M; Gudi, Ramadevi; Clark, Charles R

    2014-11-01

    Micronucleus and sister chromatid exchange (SCE) tests were performed for vapor condensate of baseline gasoline (BGVC), or gasoline with oxygenates, methyl tert-butyl ether (G/MTBE), ethyl tert butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), t-butyl alcohol (TBA), or ethanol (G/EtOH). Sprague Dawley rats (the same 5/sex/group for both endpoints) were exposed to 0, 2000, 10,000, or 20,000mg/m(3) of each condensate, 6h/day, 5days/week over 4weeks. Positive controls (5/sex/test) were given cyclophosphamide IP, 24h prior to sacrifice at 5mg/kg (SCE test) and 40mg/kg (micronucleus test). Blood was collected from the abdominal aorta for the SCE test and femurs removed for the micronucleus test. Blood cell cultures were treated with 5μg/ml bromodeoxyuridine (BrdU) for SCE evaluation. No significant increases in micronucleated immature erythrocytes were observed for any test material. Statistically significant increases in SCE were observed in rats given BGVC alone or in female rats given G/MTBE. G/TAME induced increased SCE in both sexes at the highest dose only. Although DNA perturbation was observed for several samples, DNA damage was not expressed as increased micronuclei in bone marrow cells. Inclusion of oxygenates in gasoline did not increase the effects of gasoline alone or produce a cytogenetic hazard.

  14. Frequency of sister chromatid exchange and chromosomal aberrations in asbestos cement workers.

    PubMed

    Fatma, N; Jain, A K; Rahman, Q

    1991-02-01

    Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. It was shown previously that asbestos samples collected from a local asbestos factory enhanced sister chromatid exchanges (SCEs) and chromosomal aberrations in vitro using human lymphocytes. In the present study, 22 workers from the same factory and 12 controls were further investigated. Controls were matched for age, sex, and socioeconomic state. The peripheral blood lymphocytes were cultured and harvested at 48 hours for studies of chromosomal aberrations and at 72 hours for SCE frequency determinations. Asbestos workers had a raised mean SCE rate and increased numbers of chromosomal aberrations compared with a control population. Most of the chromosomal aberrations were chromatid gap and break types.

  15. In vitro genotoxicity of fipronil sister chromatid exchange, cytokinesis block micronucleus test, and comet assay.

    PubMed

    Çelik, Ayla; Ekinci, Seda Yaprak; Güler, Gizem; Yildirim, Seda

    2014-03-01

    Fipronil (FP) is a phenylpyrazole pesticide developed by the transnational company Rhône-Poulenc Agro in 1987. Data on the genotoxicity and toxicity of FP are rather inadequate. In this study, we aimed to evaluate the potential genotoxic activity of FP using the single-cell microgel electrophoresis or comet assay, sister chromatid exchanges (SCEs), and micronuclei (MN) in human peripheral blood lymphocytes. In addition, the cytokinesis block proliferation index (CBPI) and proliferation index (PRI) were measured for cytotoxicity. In this study, three different doses of FP were used (0.7, 0.3, 0.1 μg/mL). Mitomycin C (2 μg/mL) and hydrogen peroxide were used as positive controls for SCE MN test systems, and comet assay, respectively. FP induced a statistically significant increase in the MN and SCE frequency and DNA damage in a dose-dependent manner in human peripheral blood lymphocytes (p<0.01, p<0.05, for 0.7 and 0.3 μg/mL, respectively) compared with a negative control. There is no significant difference between 0.1 μg/mL and the negative control for MN frequency, but there is significant difference between all the doses of FP and negative control for SCE frequency, mitotic index, CBPI, and PRI values (p<0.01). Using the alkaline comet assay, we showed that all the doses of the FP induced DNA damage in human peripheral blood lymphocytes in vitro (p<0.05).

  16. Sister chromatid exchange analysis to monitor genotoxic chemicals. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    1996-04-01

    The bibliography contains citations concerning the use of the sister chromatid exchange (SCE) analysis for toxicological studies. SCE analysis are very sensitive measures of genotoxic damage to chromosomes. SCE toxicological studies analyzing ionizing radiation, chromium compounds, styrene, paint thinner, mercury, cigarette smoke, coal dust, fuel oil, insecticides, ethylene oxide, diesel exhaust, and polychlorinated biphenyls are discussed. SCE studies using both human and animal tissue cultures are described. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. In vitro induction of sister chromatid exchanges and chromosomal aberrations in peripheral lymphocytes of the oyster toadfish and American eel.

    PubMed

    Ellingham, T J; Christensen, E A; Maddock, M B

    1986-01-01

    A series of experiments was conducted to characterize the proliferation of oyster toadfish lymphocytes in medium containing 5-bromodeoxyuridine (BrdUrd) and to determine the effectiveness of cytogenetic endpoints for assessing the genotoxic effects of in vitro exposure of toadfish and eel lymphocytes to known mammalian clastogens. Although the rate of proliferation of toadfish lymphocytes was low compared to that of mammalian lymphocytes, the effects of increasing BrdUrd concentrations were similar, in that proliferation exhibited a concentration-dependent inhibition for concentrations above 10 microM BrdUrd, and sister chromatid exchange (SCE) frequencies exhibited a concentration-dependent increase for concentrations above 100 microM BrdUrd. Mitomycin C (MMC) and ethylene dibromide (EDB) induced concentration-dependent increases in chromatid-type exchange and SCE frequencies with least effective concentrations (control SCE frequency divided by the slope of the least-squares line) for SCE induction by MMC (6.8 X 10(-9) M) and EDB (2.6 X 10(-4) M) that were comparable to or slightly lower than those that have been obtained with mammalian in vitro systems. In vitro exposure of toadfish lymphocytes to dimethoate (DIM) induced a concentration-dependent increase in SCE frequency with a least effective concentration of 2.8 X 10(-3) M that was much higher than that observed with mammalian in vitro systems. In vitro exposure of American eel lymphocytes to MMC also induced a concentration-dependent increase in the frequency of chromosomal aberrations and SCEs with a least effective concentration for SCE induction of 2.0 X 10(-9) M. These results indicate that cytogenetic endpoints can be effectively scored with cultured lymphocytes from these and perhaps other fish species with comparable karyotypes that contain an average of at least 0.07 pg DNA/chromosome.

  18. An increase in telomere sister chromatid exchange in murine embryonic stem cells possessing critically shortened telomeres

    SciTech Connect

    Wang, Yisong; Giannone, Richard J; Wu, Jun; Gomez, Marla V; Liu, Yie

    2005-01-01

    Telomerase deficiency leads to a progressive loss of telomeric DNA that eventually triggers cell apoptosis in human primary cells during prolonged growth in culture. Rare survivors can maintain telomere length through either activation of telomerase or recombination-based telomere lengthening, and thus proliferate indefinitely. We have explored the possibility that telomeres may be maintained through telomere sister chromatid exchange (T-SCE) in murine telomere reverse transcriptase-deficient (mTert -/-) splenocytes and ES cells. Because telomerase deficiency leads to gradual loss of telomeric DNA in mTert -/- splenocytes and ES cells and eventually to chromosomes with telomere signal-free ends (SFEs), we examined these cell types for evidence of sister chromatid exchange at telomeres, and observed an increase in T-SCEs only in a subset of mTert -/- splenocytes or ES cells that possessed multiple SFEs. Furthermore, T-SCEs were more often detected in ES cells than in splenocytes that harbored a similar frequency of SFEs. In mTert heterozygous (mTert +/-) ES cells or splenocytes, which are known to exhibit a decrease in average telomere length but no SFEs, no increase in T-SCE was observed. In addition to T-SCE, other genomic rearrangements (i.e., SCE) were also significantly increased in mTert -/- ES cells possessing critically short telomeres, but not in splenocytes. Our results suggest that animals and cell culture differ in their ability to carry out genomic rearrangements as a means of maintaining telomere integrity when telomeres become critically shortened.

  19. Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

    SciTech Connect

    Harrison, F.L.; Rice, D.W. Jr., Moore, D.H.

    1984-07-01

    Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to /sup 60/Co gamma rays at a low dose rate of from 4.8 x 10/sup -5/ to 1.2 x 10/sup -1/ Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10/sup -5/M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h (/sup 60/Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving /sup 60/Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables.

  20. Sister chromatid exchanges in mouse after exposure to pulse-wave ultrasound in utero.

    PubMed

    Shintaku, Y; Takabayashi, T; Sasaki, H; Ozawa, N; Yajima, A

    1993-06-01

    The induction of sister chromatid exchanges (SCEs) was investigated in mice after a ten min exposure, in vivo, to 2 MHz focused, pulse-wave ultrasound with a pulse repetition rate of 1000 Hz, pulse duration of 10 microseconds. The bone marrow cells of the pregnant female mice and the fetal liver cells were analyzed. The cell cycle specific metaphase patterns were additionally evaluated. In the bone marrow cells, the mean frequencies of SCEs were 2.77 in control, 3.56 in the cells exposed to ultrasound at 586.2 mW/cm2 (spatial average temporal average, SATA); in the fetal liver cells, 2.64 in control, 3.84 in the cells exposed. The frequencies of SCEs significantly were increased by the treatment. Faster cell kinetics was observed in fetal liver cells than bone marrow cells of pregnant female. But there was no cell-growth inhibitory effect of ultrasound on both bone marrow and fetal liver cells. In fetal liver cells, the critical acoustic power was 160.0-278.9 mW/cm2 (SATA).

  1. Sister chromatid exchanges and chromosomal aberrations in lymphocytes of nurses handling cytostatic agents.

    PubMed

    Benhamou, S; Pot-Deprun, J; Sancho-Garnier, H; Chouroulinkov, I

    1988-03-15

    A cohort study of 29 nurses who constantly handled cytostatic drugs, and 29 controls matched according to sex and age, was carried out between 1983 and 1986. Cytogenetic damage was assessed by sister chromatid exchanges (SCE) and chromosomal aberrations. No significant increase in mean number of SCE was found for nurses (7.37) as compared to matched controls (7.00), whereas a significant excess of SCE (p less than 0.001) was observed for smokers (8.23) as compared to non-smokers (6.75). The number of SCE was studied in relation to the amount and nature of cytostatics handled as well as to the duration of exposure. A significant association (p less than 0.05) was found between individual mean number of SCE and the total number of drugs handled after adjustment for confounding factors. In contrast, the number of SCE was not significantly related to the nature of drugs handled or to the duration of exposure. With regard to chromosomal damage, no significant difference was observed between nurses and controls in gap, break, dicentric and translocation frequencies.

  2. Elevated sister chromatid exchange frequencies in New Zealand Vietnam War veterans.

    PubMed

    Rowland, R E; Edwards, L A; Podd, J V

    2007-01-01

    From July 1965 until November 1971, New Zealand Defence Force Personnel fought in the Vietnam War. During this time more than 76,500,000 litres of phenoxylic herbicides were sprayed over parts of Southern Vietnam and Laos, the most common being known as 'Agent Orange'. The current study aimed to ascertain whether or not New Zealand Vietnam War veterans show evidence of genetic disturbance arising as a consequence of their now confirmed exposure to these defoliants. A sample group of 24 New Zealand Vietnam War veterans and 23 control volunteers were compared using an SCE (sister chromatid exchange) analysis. The results from the SCE study show a highly significant difference (P < 0.001) between the mean of the experimental group (11.05) and the mean of a matched control group (8.18). The experimental group also has an exceptionally high proportion of HFCs (cells with high SCE frequencies) above the 95th percentile compared to the controls (11.0 and 0.07%, respectively). We conclude that the New Zealand Vietnam War veterans studied here were exposed to a clastogenic substance(s) which continues to exert an observable genetic effect today, and suggest that this is attributable to their service in Vietnam.

  3. Elevated sister chromatid exchange phenotype of Bloom syndrome cells is complemented by human chromosome 15.

    PubMed Central

    McDaniel, L D; Schultz, R A

    1992-01-01

    Bloom syndrome (BSx) is a rare autosomal-recessive chromosome-instability disorder manifested by a constellation of clinical features including a significant predisposition to early onset of neoplasia. BSx cells display cytogenetic abnormalities, the pathognomonic feature being an increased rate of spontaneous sister chromatid exchanges (SCEs), 10- to 15-fold more frequent than SCEs seen in control cells. Identification of the primary biochemical defect in BSx and its relationship to SCE frequency and neoplasia have been complicated by reports that BSx cell lines exhibit defects in the structure and/or activity of a number of different enzymes. The rare occurrence of the disorder and lack of informative families have precluded mapping of the primary defect by standard linkage analysis. We have utilized BSx cells as recipients for microcell-mediated chromosome transfer to map a locus that renders complementation of the elevated SCE phenotype. Studies with the BSx cell line GM08505 demonstrated a stable frequency of SCEs 10-fold higher than control values, offering a phenotype suitable for complementation studies. Transfer of different independent human chromosomes from somatic cell hybrids into BSx cells permitted identification of a single chromosome that dramatically reduced the SCE frequency to a level near that seen in control cells. Detailed characterization revealed this complementing element to be human chromosome 15. Images PMID:1518822

  4. Elevated sister chromatid exchange frequencies in New Zealand Vietnam War veterans.

    PubMed

    Rowland, R E; Edwards, L A; Podd, J V

    2007-01-01

    From July 1965 until November 1971, New Zealand Defence Force Personnel fought in the Vietnam War. During this time more than 76,500,000 litres of phenoxylic herbicides were sprayed over parts of Southern Vietnam and Laos, the most common being known as 'Agent Orange'. The current study aimed to ascertain whether or not New Zealand Vietnam War veterans show evidence of genetic disturbance arising as a consequence of their now confirmed exposure to these defoliants. A sample group of 24 New Zealand Vietnam War veterans and 23 control volunteers were compared using an SCE (sister chromatid exchange) analysis. The results from the SCE study show a highly significant difference (P < 0.001) between the mean of the experimental group (11.05) and the mean of a matched control group (8.18). The experimental group also has an exceptionally high proportion of HFCs (cells with high SCE frequencies) above the 95th percentile compared to the controls (11.0 and 0.07%, respectively). We conclude that the New Zealand Vietnam War veterans studied here were exposed to a clastogenic substance(s) which continues to exert an observable genetic effect today, and suggest that this is attributable to their service in Vietnam. PMID:17431321

  5. Incorporation of deoxyuridine monophosphate into DNA increases the sister-chromatid exchange yield

    SciTech Connect

    Pardo, E.G.; Hernandez, P.; Gutierrez, C.

    1987-02-01

    The effect of a treatment with 5-fluoro-2'-deoxyuridine (FdUrd) in combination with 2'-deoxyuridine (dUrd) on cell proliferation, incorporation of DNA precursors into DNA and sister-chromatid exchanges (SCEs) has been analyzed in Allium cepa meristem cells. FdUrd in the range 10/sup -9/-5 x 10/sup -7/ M produced a dose- and time-dependent decrease in the amount of cells in mitosis. This inhibitory effect could be reversed by 70-80% in short-term (6 h) experiments, by exogenously supplied dUrd at a concentration of 10/sup -1/ M. However, at the highest FdUrd dose tested (10/sup -7/ M), 10/sup -4/ M dUrd could not reverse the FdUrd effect in long-term experiments as shown by analyzing the kinetics of synchronous cell populations. DNA extracted from cells pulsed with (6-/sup 3/H)dUrd in the presence of FdUrd and 6-amino-uracil (6-AU), an inhibitor of uracil-DNA glycosylase, contained a small amount of label in the form of (6-/sup 3/H)dUMP. Thus the authors conclude that under the experimental conditions, exogenously supplied dUrd may be metabolized intracellularly to 2'-deoxyuridine triphosphate (dUTP) and that this deoxynucleotide may eventually be mis-incorporated into DNA. By analyzing SCE levels in third division chromosomes of cells treated with FdUrd and dUrd during their second cycle, they has scored a 6-fold increase in the reciprocal SCE level which demonstrates that the replication of a dUMP-containing DNA template leads to a higher SCE yield.

  6. The Relationship between Dioxin Congeners in the Breast Milk of Vietnamese Women and Sister Chromatid Exchange

    PubMed Central

    Suzuki, Hiroyuki; Kido, Teruhiko; Okamoto, Rie; Nhu, Dang Duc; Nishijo, Muneko; Nakagawa, Hideaki; Tawara, Kenji; Horikawa, Hiroaki; Sato, Yuko; Dung, Phung Tri; Thom, Le Hong; Hung, Nguyen Ngoc

    2014-01-01

    The aim of this study was to clarify the relationship between dioxin concentrations in breast milk and the sister chromatid exchange (SCE) frequency in women from herbicide-sprayed and non sprayed areas. Blood samples were taken from 21 women with high TCDD (tetrachlorodibenzo-p-dioxin) levels from sprayed areas, 23 women with moderate TCDD levels from sprayed areas, and 19 women from non sprayed areas to determine their SCE frequency. The SCE frequencies for the high and moderate TCDD groups from the sprayed area and for the non sprayed area group were 2.40, 2.19, and 1.48 per cell, respectively. Multiple regression analysis showed that the standardized β values for 1,2,3,6,7,8-hexaCDD (β = 0.60), 1,2,3,4,6,7,8-heptaCDD (β = 0.64), and octaCDD (β = 0.65) were higher than those for TCDD (β = 0.34) and 1,2,3,7,8-pentaCDD (β = 0.42). The adjusted R2 value for polyCDDs (R2 = 0.38) was higher than that for polyCDD toxic equivalents (TEQ (toxic equivalents); R2 = 0.23). This study therefore shows that levels of hexa-, hepta-, and octaCDD, which were previously regarded as being less toxic than TCDD, are closely related to SCE frequency and that the level of dioxin (pg/g lipid) is potentially more useful as an indicator than TEQ value for explaining SCE frequency. PMID:24786289

  7. The relationship between dioxin congeners in the breast milk of Vietnamese women and sister chromatid exchange.

    PubMed

    Suzuki, Hiroyuki; Kido, Teruhiko; Okamoto, Rie; Nhu, Dang Duc; Nishijo, Muneko; Nakagawa, Hideaki; Tawara, Kenji; Horikawa, Hiroaki; Sato, Yuko; Dung, Phung Tri; Thom, Le Hong; Hung, Nguyen Ngoc

    2014-01-01

    The aim of this study was to clarify the relationship between dioxin concentrations in breast milk and the sister chromatid exchange (SCE) frequency in women from herbicide-sprayed and non sprayed areas. Blood samples were taken from 21 women with high TCDD (tetrachlorodibenzo-p-dioxin) levels from sprayed areas, 23 women with moderate TCDD levels from sprayed areas, and 19 women from non sprayed areas to determine their SCE frequency. The SCE frequencies for the high and moderate TCDD groups from the sprayed area and for the non sprayed area group were 2.40, 2.19, and 1.48 per cell, respectively. Multiple regression analysis showed that the standardized β values for 1,2,3,6,7,8-hexaCDD (β = 0.60), 1,2,3,4,6,7,8-heptaCDD (β = 0.64), and octaCDD (β = 0.65) were higher than those for TCDD (β = 0.34) and 1,2,3,7,8-pentaCDD (β = 0.42). The adjusted R² value for polyCDDs (R² = 0.38) was higher than that for polyCDD toxic equivalents (TEQ (toxic equivalents); R² = 0.23). This study therefore shows that levels of hexa-, hepta-, and octaCDD, which were previously regarded as being less toxic than TCDD, are closely related to SCE frequency and that the level of dioxin (pg/g lipid) is potentially more useful as an indicator than TEQ value for explaining SCE frequency. PMID:24786289

  8. In vitro induction of sister chromatid exchanges and chromosomal aberrations in peripheral lymphocytes of the oyster toadfish and American eel

    SciTech Connect

    Ellingham, T.J.; Christensen, E.A.; Maddock, M.B.

    1986-01-01

    A series of experiments was conducted to characterize the proliferation of oyster toadfish lymphocytes in medium containing 5-bromodeoxyuridine (BrdUrd) and to determine the effectiveness of cytogenetic endpoints for assessing the genotoxic effects of in vitro exposure of toadfish and eel lymphocytes to known mammalian clastogens. Although the rate of proliferation of toadfish lymphocytes was low compared to that of mammalian lymphocytes, the effects of increasing BrdUrd concentrations were similar. Mitomycin C (MMC) and ethylene dibromide (EDB) induced concentration-dependent increases in chromatid-type exchange and SCE frequencies with least effective concentrations for SCE induction by MMC (6.8 x 10/sup -9/ M) and EDB (2.6 x 10/sup -4/ M) that were comparable to or slightly lower than those that have been obtained with mammalian in vitro systems. In vitro exposure of toadfish lymphocytes to dimethoate (DIM) induced a concentration-dependent increase in SCE frequency with a least effective concentration of 2.8 x 10/sup -3/ M that was much higher than that observed with mammalian in vitro systems. In vitro exposure of American eel lymphocytes to MMC also induced a concentration-dependent increase in the frequency of chromosomal aberrations and SCEs with a least effective concentration for SCE induction of 2.0 x 10/sup -9/ M. These results indicate that cytogenetic endpoints can be effectively scored with cultured lymphocytes from these and perhaps other fish species with comparable karyotypes that contain an average of at least 0.07 pg DNA/chromosome.

  9. Biochemical and cytogenetical characterization of Chinese hamster ovary X-ray-sensitive mutant cells xrs 5 and xrs 6. V. The correlation of DNA strand breaks and base damage to chromosomal aberrations and sister-chromatid exchanges induced by X-irradiation.

    PubMed

    Darroudi, F; Natarajan, A T; van der Schans, G P; van Loon, A A

    1990-03-01

    The X-ray-sensitive Chinese hamster ovary (CHO) mutant cell lines xrs 5 and xrs 6 were used to study the relation between X-ray-induced DNA lesions and biological effects. The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCE) were determined in wild-type CHO-K1 as well as mutants xrs 5 and xrs 6 cells following X-irradiation under aerobic and anaerobic conditions. Furthermore, we used a newly developed immunochemical method (based on the binding of a monoclonal antibody to single-stranded DNA) to assay DNA single-strand breaks (SSBs) induced by gamma-rays in these CHO cells, after a repair time of up to 4 h. For all cell lines tested the frequency of X-ray-induced chromosomal aberrations was strongly increased after irradiation in air compared with hypoxic conditions. When compared to the wild-type line, the xrs mutants known to have a defect in repair of DNA double-strand breaks (DSBs) exhibited a markedly enhanced sensitivity to aerobic irradiation, and a high OER (oxygen enhancement ratio) of 2.8-3.5, compared with 1.8-2 in CHO-K1 cells. The induction of SCE by X-rays was relatively little affected in CHO-K1 irradiated in air compared with hypoxic conditions (OER = 0.8), and in xrs 5 (OER = 0.7). A dose-dependent increase in the frequency of SCEs was obtained in xrs 6 cells treated with X-rays in air, and a further increase by a factor of 2 was evident under hypoxic conditions (OER = 0.4). With the immunochemical assay of SSB following gamma-irradiation, no difference was found between wild-type and mutant strains in the number of SSBs induced. The observed rate of rejoining of SSBs was also the same for all cell lines studied. PMID:2407948

  10. Understanding the origins of UV-induced recombination through manipulation of sister chromatid cohesion.

    PubMed

    Covo, Shay; Ma, Wenjian; Westmoreland, James W; Gordenin, Dmitry A; Resnick, Michael A

    2012-11-01

    Ultraviolet light (UV) can provoke genome instability, partly through its ability to induce homologous recombination (HR). However, the mechanism(s) of UV-induced recombination is poorly understood. Although double-strand breaks (DSBs) have been invoked, there is little evidence for their generation by UV. Alternatively, single-strand DNA lesions that stall replication forks could provoke recombination. Recent findings suggest efficient initiation of UV-induced recombination in G1 through processing of closely spaced single-strand lesions to DSBs. However, other scenarios are possible, since the recombination initiated in G1 can be completed in the following stages of the cell cycle. We developed a system that could address UV-induced recombination events that start and finish in G2 by manipulating the activity of the sister chromatid cohesion complex. Here we show that sister-chromatid cohesion suppresses UV-induced recombination events that are initiated and resolved in G2. By comparing recombination frequencies and survival between UV and ionizing radiation, we conclude that a substantial portion of UV-induced recombination occurs through DSBs. This notion is supported by a direct physical observation of UV-induced DSBs that are dependent on nucleotide excision repair. However, a significant role of nonDSB intermediates in UV-induced recombination cannot be excluded.

  11. Sister chromatid exchange test in river buffalo lymphocytes treated in vitro with furocoumarin extracts.

    PubMed

    Iannuzzi, Alessandra; Perucatti, Angela; Genualdo, Viviana; Pauciullo, Alfredo; Melis, Rita; Porqueddu, Claudio; Marchetti, Mauro; Usai, Marianna; Iannuzzi, Leopoldo

    2016-09-01

    Furocoumarin extracts from Psoralea morisiana, the endemic Sardinian legume species, were tested for their mutagenic potential on river buffalo blood cells. The results obtained performing the sister chromatid exchange (SCE) test in blood cultures of five river buffalo calves (exposure to furocoumarins for 72h) and five cows (exposure to furocoumarins for 3h, in the absence and presence of S9 metabolic activator) are reported. Significant differences in mean values of SCEs were observed in cells of calves compared to control cells (unexposed), but no differences in SCE mean values were found between treated and untreated cells of cows in the presence or absence of S9. SCE mean values were much higher in cells of cows (exposed and control) than in cells of calves. Indeed, in calf cells, SCE mean values/cell (±SD) were 6.66±2.45 in the control and 7.63±3.01, 9.03±3.90, 9.53±3.60 and 9.99±3.41 in treated cells at 50, 100, 200 and 400 µg/ml of furocoumarin extracts, respectively. In cow cells, grown in presence of S9, SCE mean values/cell were 11.49±4.78 and 11.65±5.19 in treated cells at 100 and 200 µg/ml of furocoumarins and 11.66±5.45 in the control. In cow cells grown in absence of S9, SCE mean values were 11.81±6.14 in the control and 12.35±7.09 and 12.01±5.43, respectively, in the presence of 100 and 200 µg/ml of furocoumarins. Despite their higher SCE values in the absence of S9, no statistically significant differences were found when these values were compared with those shown in presence of S9, suggesting no mutagenic action of furocoumarins in cows, at the doses used in this study. PMID:27180332

  12. Sister-chromatid exchanges and cell-cycle delay in Chinese hamster V79 cells treated with 9 organophosphorus compounds (8 pesticides and 1 defoliant).

    PubMed

    Chen, H H; Sirianni, S R; Huang, C C

    1982-03-01

    Significant increase of sister-chromatid exchanges (SCE) in V79 cells treated with 2 organophosphorus pesticides (OPP), fenthion and oxydemeton-methyl, was observed. The other 7 compounds (6 OPP and 1 defoliant) namely, amaze, azinphos-methyl, bolstar, DEF-defoliant, fensulfothion, monitor and nemacur caused no increase of SCE frequencies at the doses tested. All the compounds except fensulfothion and oxydemeton-methyl induced cell-cycle delay in varying degrees. Cell-cycle delay caused by an OPP was found to be dose-dependent. Based on these data as well as others reported, it would appear that OPP which induce no SCE increase and no or slight cell-cycle delay could be considered as good candidates to substitute the pesticides that have been found to be harmful to the environment. PMID:6211614

  13. Sister-chromatid exchanges and cell-cycle delay in Chinese hamster V79 cells treated with 9 organophosphorus compounds (8 pesticides and 1 defoliant).

    PubMed

    Chen, H H; Sirianni, S R; Huang, C C

    1982-03-01

    Significant increase of sister-chromatid exchanges (SCE) in V79 cells treated with 2 organophosphorus pesticides (OPP), fenthion and oxydemeton-methyl, was observed. The other 7 compounds (6 OPP and 1 defoliant) namely, amaze, azinphos-methyl, bolstar, DEF-defoliant, fensulfothion, monitor and nemacur caused no increase of SCE frequencies at the doses tested. All the compounds except fensulfothion and oxydemeton-methyl induced cell-cycle delay in varying degrees. Cell-cycle delay caused by an OPP was found to be dose-dependent. Based on these data as well as others reported, it would appear that OPP which induce no SCE increase and no or slight cell-cycle delay could be considered as good candidates to substitute the pesticides that have been found to be harmful to the environment.

  14. Unequal mitotic sister chromatid exchange: A rare mechanism for chromosomal abnormality resulting in duplication/deletion of chromosome 7q

    SciTech Connect

    Eydoux, P.; Ortenberg, J.; Chalifoux, N.

    1994-09-01

    We report a case of unequal mitotic chromatid exchange, which has rarely been reported as a mechanism for microscopic chromosomal anomalies. The proposita was born at 40 weeks, after an uneventful pregnancy, of parents with a negative family history. The baby was small for gestational age and had dysmorphic features, including scaphocephaly, bilateral epicanthal folds and palpebral ptosis, mild hypertelorism, hypoplasia of orbital contours, right coloboma, bulbous prominent nose, retrognathism, downturned mouth, low set posteriorly rotated ears, tapering of the limbs. bilateral Sydney creases. At 5 months, she was under the 5th percentile for height, weight and head circumference, and had a mild developmental delay. The karyotype showed an abnormality of chromosome 7 in all cells, half with a duplication and half with a deletion of the same region; 46,XX,del(7)(q33{yields}q34)/46,XX,dup(7)(q33{yields}q34). This chromosomal abnormality could be explained by an unequal chromatid exchange occuring in the first mitosis of the embryo. To our knowledge, only one such human microscopic abnormality, involving chromosome Y, has been reported to date. This type of genetic unbalance could be missed by molecular techniques.

  15. Genotoxic assessment in peripheral blood lymphocytes of post-polio individuals using sister chromatid exchange analysis and micronucleus assay.

    PubMed

    Bhattacharya, Saurabh Kumar; Saraswathy, Radha; Sivakumar, E

    2011-07-01

    Environmental pollution is a complex issue because of the diversity of anthropogenic agents, both chemical and physical, that have been detected and catalogued. The consequences to biota from exposure to genotoxic agents present an additional problem because of the potential for these agents to produce adverse change at the cellular and organism levels. Past studies in virus have focused on structural damage to the DNA of environmental species that may occur after exposure to genotoxic agents and the use of this information to document exposure and to monitor remediation. In an effort to predict effects at the population, community and ecosystem levels, in the present study, we attempt to characterize damage occurring through genotoxic agents like 5-bromo-2-deoxyuridine, BrdU, using sister chromatid exchange technique and the formation of micronuclei (MN) in the peripheral lymphocytes of the post-polio syndrome sequelae affected by poliovirus. Analysis of structural chromosomal aberrations (CAs) and involvement of the specific chromosome break were pursued in this study. They revealed a significantly higher incidence of CAs (chromatid and chromosome breaks) in patients compared with controls, where the specific chromosome break has emerged as specific. Also, the maximum numbers of breaks were found to be in chromosome 1 at the position 1p36.1. The results also suggest a correlation between CAs and content of MN.

  16. Effects of radiation on frequency of chromosomal aberrations and sister chromatid exchange in the benthic worm Neanthes arenaceodentata

    SciTech Connect

    Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.; Varela, M.

    1983-04-01

    Traditional bioassays are unsuitable for assessing sublethal effects of low levels of radioactivity because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration (CA) and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. Newly hatched larvae were exposed to two radiation exposure regimes. Groups of 100 larvae were exposed to either x rays delivered at high dose rates (0.7 Gy min/sup -1/) or to /sup 60/Co gamma rays delivered at low dose rates (4.8 X 10/sup -5/ to 1.2 X 10/sup -1/ Gy h/sup -1/). After irradiation, the larvae were exposed to 3 X 10/sup -5/M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h (/sup 60/Co-irradiated larvae). Slides of larval cells were prepared for observation of CAs and SCEs. Frequencies of CAs were determined in first division cells; frequencies of SCEs were determined in second division cells. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but an x-ray dose greater than or equal to 2 Gy was required to observe a significant increase. Worm larvae receiving /sup 60/Co irradiation showed elevated SCE frequencies; a significant increase in SCE frequency was observed at 0.6 Gy. 49 references, 2 figures.

  17. Assessment of micronuclei and sister chromatid exchange frequency in the petroleum industry workers in province of Vojvodina, Republic of Serbia.

    PubMed

    Mrdjanović, Jasminka; Šolajić, Slavica; Dimitrijević, Sladjana; Đan, Igor; Nikolić, Ivan; Jurišić, Vladimir

    2014-07-01

    Persons who work with petroleum and petroleum derivatives (PPD) are potentially at risk of developing cancer mostly due to the carcinogenity of benzene. Therefore, the aim of this study was to determine in which degree occupational exposure of workers to PPD causes damage to DNA by analysis of micronuclei (MN), sister chromatid exchanges (SCE) and proliferation index (PI). 30 workers of refinery in Novi Sad, participated in the study as exposed and 30 volunteers as control group. Workers exposed to PPD had significantly higher values of MN and SCE in comparison to controls. Exposition time to PPD and type of working place have also significantly effects to DNA damage. The influence of confounding factor such as smoking and age were also evaluated.

  18. Induction of sister chromatid exchange in preimplantation mouse embryos in vitro by /sup 3/H-thymidine or ultraviolet light in combination with caffeine

    SciTech Connect

    Mueller, W.U.S.; Spindle, A.

    1986-01-01

    Preimplantation mouse embryos were exposed in vitro to /sup 3/H-thymidine (25, 100, or 250 Bq/ml) or ultraviolet (UV) light (1.35 or 4.05 J/m2), either alone or in combination with caffeine (1 mM with /sup 3/H-thymidine and 0.5 mM with UV light). Exposure to /sup 3/H-thymidine lasted for 2 days, from the two-cell stage to the late morula/early blastocyst stage, and UV radiation was applied acutely at the late morula/early blastocyst stage. The effects were quantified by the sister chromatid exchange (SCE) assay. All three agents induced SCEs when used singly. /sup 3/H-thymidine was effective in inducing SCEs only at 250 Bq/ml, whereas UV light was effective at both fluences. Although caffeine did not induce SCEs when it was added before exposure to bromodeoxyuridine (BrdUrd), which is used to visualize SCEs, it did induce SCEs when present during the entire culture period (/sup 3/H-thymidine experiments) or during incubation in BrdUrd (UV experiments). Caffeine markedly enhanced the SCE-inducing effect of UV light but did not influence the effect of /sup 3/H-thymidine.

  19. In vitro studies of biological effects of cigarette smoke condensate. II. Induction of sister-chromatid exchanges in human lymphocytes by weakly acidic, semivolatile constituents.

    PubMed

    Jansson, T; Curvall, M; Hedin, A; Enzell, C R

    1986-03-01

    Cigarette smoke condensate is known to enhance the frequency of sister-chromatid exchanges (SCE) in human lymphocytes in vitro and some of the activity has been found in the most volatile part of the particulate phase, the semivolatile fraction. In this study we have investigated the chemical composition and the SCE-inducing activity of the weakly acidic, semivolatile fraction of a cigarette smoke condensate. A number of individual weakly acidic compounds were also tested for their SCE-inducing effects. The weakly acidic fraction was separated by preparative gel chromatography into 11 subfractions (F1-F11). The chemical composition was determined by gas chromatography and gas chromatography-mass spectrometry. Measurements of the effects on SCE in human lymphocytes were used to evaluate the genotoxic effects. All fractions except F11 induced SCE in a dose-dependent way. The most active fraction was F4 which contained mainly alkyl-2-hydroxy-2-cyclopenten-1-ones. The individual compounds to be tested for induction of SCE were selected on the basis of their abundance in the weakly acidic subfractions and on the basis of their occurrence in the environment. Of 23 tested compounds, most of which were alkylphenols, 7 induced SCE, i.e., catechol, 2-(1-propenyl)phenol, cyclotene, maltol, isoeugenol, 2-methoxyphenol (guaiacol) and vanillin. Many of these are important flavor components that occur not only in tobacco and tobacco smoke but also in food, candies, beverages and perfumes.

  20. Dose--response of initial G2-chromatid breaks induced in normal human fibroblasts by heavy ions

    NASA Technical Reports Server (NTRS)

    Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Takai, N.; Wu, H.; Cucinotta, F. A.; Dicello, J. F. (Principal Investigator)

    2001-01-01

    PURPOSE: To investigate initial chromatid breaks in prematurely condensed G2 chromosomes following exposure to heavy ions of different LET. MATERIAL AND METHODS: Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (13 keV/ microm, 80 keV/microm), silicon (55 keV/microm) and iron (140 keV/microm, 185keV/microm, 440keV/microm) ions. Chromosomes were prematurely condensed using calyculin-A. Initial chromatid-type and isochromatid breaks in G2 cells were scored. RESULTS: The dose response curves for total chromatid breaks were linear regardless of radiation type. The relative biological effectiveness (RBE) showed a LET-dependent increase, peaking around 2.7 at 55-80keV/microm and decreasing at higher LET. The dose response curves for isochromatid-type breaks were linear for high-LET radiations, but linear-quadratic for gamma-rays and 13 keV/microm carbon ions. The RBE for the induction of isochromatid breaks obtained from linear components increased rapidly between 13keV/microm (about 7) and 80keV/microm carbon (about 71), and decreased gradually until 440 keV/microm iron ions (about 66). CONCLUSIONS: High-LET radiations are more effective at inducing isochromatid breaks, while low-LET radiations are more effective at inducing chromatid-type breaks. The densely ionizing track structures of heavy ions and the proximity of sister chromatids in G2 cells result in an increase in isochromatid breaks.

  1. Effect of oral administration of mutagens found in food on the frequency of sister chromatid exchanges in the colonic epithelium of mice

    SciTech Connect

    Couch, D.B.; Stuart, E.; Heddle, J.A.

    1987-01-01

    Epidemiological studies indicate there is a link between dietary factors and the incidence of colon cancer, and it has been suggested mutagens in foods might be responsible for initiating the carcinogenic process. Some food mutagens are formed during the cooking process. For example, certain heterocyclic amines, including Trp-P-2 (3-amino-1-methyl-5H-pyrido(4,3-n) indole) and MeIQ (2-amino-3,4-dimethylimidazo(4,5-f)quinoline), which have been isolated from broiled meat and fish at low (ng/g) levels, are extremely potent mutagens in the Ames Salmonella/microsome test and can induce mutation in cultured mammalian cells as well. Other mutagens in foods are natural products; quercetin, a flavanoid widely distributed in plant products, is mutagenic to Salmonella and cultured mammalian cells. As most of the evidence implicating substance in food as mutagenic carcinogens comes from in vitro studies, it is of interest to determine whether these compounds can also exert genotoxic effects in vivo, particularly in colonic tissue. The ability to induce nuclear aberrations in vivo in murine colonic epithelial tissue has been suggested to be a property of colon carcinogens specifically, and several mutagens found in cooked food, including MeIQ and Trp-P-2, have been found to produce such nucleotoxicity. The authors report here tests of the ability of MeIQ, Trp-P-2, and quercetin to induce sister chromatid exchanges (SCEs) in the colonic epithelium of mice.

  2. Induction of sister chromatid exchanges by tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in human and hamster cells.

    PubMed

    Zimonjic, D; Popescu, N C; DiPaolo, J A

    1989-04-01

    4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a nicotine derived N-nitrosamine, is a carcinogen that induces tumors in mice, rats and hamsters. To assess the ability of NNK to interact with the cellular DNA as an essential step in carcinogenesis, the induction of sister chromatid exchange (SCE) was examined in cultured normal human lymphocytes (HL) and Chinese hamster V79 cells. SCE formation is a sensitive indicator of carcinogen-DNA interaction that correlates with the induction of mutation and neoplastic cell transformation. HL and V79 cells were treated for 2 h with 20, 50, 100 and 200 micrograms/ml of NNK with and without application of metabolic activation S-9 mixture, and subsequently incubated for two rounds of replication in the presence of 5-bromodeoxyuridine required for SCE visualization. In V79 cells NNK produced a dose-dependent increase in SCE only with metabolic activation. In HL NNK induced a small but statistically significant increase in SCE with or without metabolic activation. These data provide the first evidence that NNK and/or its metabolic derivatives are able to induce DNA damage leading to SCE formation both in hamster and human cells. The differences in response between the two cell types suggests the existence of a difference in susceptibility associated with NNK metabolism and its interaction with cellular DNA. PMID:2649269

  3. Effects of coal combustion products and metal compounds on sister chromatid exchange (SCE) in a macrophagelike cell line

    PubMed Central

    Andersen, Ole

    1983-01-01

    Investigations of genotoxic effects of particles have almost exclusively been performed by organic extraction, while direct investigations in cells capable of engulfing particles have only been performed in few cases. Thus, in most studies, the eventual effects of particle-associated metal compounds have remained undiscovered. The present study attempted direct measurement of genotoxic effects of particulate coal combustion products by using the P388D1 macrophage cell line. The capability of these cells for phagocytosis was demonstrated with insoluble particles. The sister chromatid exchange (SCE) test was used for measuring genotoxic effects of test compounds. Dimethylnitrosamine and benzo(a)pyrene did not increase SCE, indicating that the P388D1 cell line has lost the capacity for metabolism of latent organic carcinogens, reducing the value of these cells for evaluating genotoxic effects of complex particles. Indirect evidence has been obtained that the cell line may be infected with a virus. Thus, interactions between virus and test compound may lead to erroneous results. This should be kept in mind during evaluation of the results. The effects of metals with reported carcinogenic or mutagenic effects on SCE were compared in P388D1 cells and human lymphocytes: NaAsO2, CdCl2, K2Cr2O7, CoCl2, CH3HgCl and MnSO4 increased SCE in both cell systems. Pb(CH3COO)2, BeSO4 and NiSO4 had a weak effect on SCE in P388D1. Pb(CH3COO)2 and NiSO4, but not BeSO4, increased SCE in human lymphocytes. Cr(CH3COO)3 increased SCE in human lymphocytes at high concentration, but was a strong inducer of increased SCE in P388D1 cells, which take up Cr(III) by phagocytosis. This suggests that the Cr(III) ion is an ultimate carcinogenic form of chromium. Generally P388D1 cells and human lymphocytes respond to in vitro exposure to metals in agreement with reported mutagenic/carcinogenic effects of the metals. Of four precipitated coal fly ash samples tested, only one sample (from an

  4. Effects of coal combustion products and metal compounds on sister chromatid exchange (SCE) in a macrophagelike cell line.

    PubMed

    Andersen, O

    1983-01-01

    Investigations of genotoxic effects of particles have almost exclusively been performed by organic extraction, while direct investigations in cells capable of engulfing particles have only been performed in few cases. Thus, in most studies, the eventual effects of particle-associated metal compounds have remained undiscovered. The present study attempted direct measurement of genotoxic effects of particulate coal combustion products by using the P388D(1) macrophage cell line. The capability of these cells for phagocytosis was demonstrated with insoluble particles. The sister chromatid exchange (SCE) test was used for measuring genotoxic effects of test compounds. Dimethylnitrosamine and benzo(a)pyrene did not increase SCE, indicating that the P388D(1) cell line has lost the capacity for metabolism of latent organic carcinogens, reducing the value of these cells for evaluating genotoxic effects of complex particles. Indirect evidence has been obtained that the cell line may be infected with a virus. Thus, interactions between virus and test compound may lead to erroneous results. This should be kept in mind during evaluation of the results. The effects of metals with reported carcinogenic or mutagenic effects on SCE were compared in P388D(1) cells and human lymphocytes: NaAsO(2), CdCl(2), K(2)Cr(2)O(7), CoCl(2), CH(3)HgCl and MnSO(4) increased SCE in both cell systems. Pb(CH(3)COO)(2), BeSO(4) and NiSO(4) had a weak effect on SCE in P388D(1). Pb(CH(3)COO)(2) and NiSO(4), but not BeSO(4), increased SCE in human lymphocytes. Cr(CH(3)COO)(3) increased SCE in human lymphocytes at high concentration, but was a strong inducer of increased SCE in P388D(1) cells, which take up Cr(III) by phagocytosis. This suggests that the Cr(III) ion is an ultimate carcinogenic form of chromium. Generally P388D(1) cells and human lymphocytes respond to in vitro exposure to metals in agreement with reported mutagenic/carcinogenic effects of the metals. Of four precipitated coal fly ash

  5. In utero analysis of sister chromatid exchange: alterations in suscptibility to mutagenic damage as a function of fetal cell type and gestational age.

    PubMed Central

    Kram, D; Bynum, G D; Senula, G C; Bickings, C K; Schneider, E L

    1980-01-01

    Frequencies of baseline and cyclophosphamide-induced sister chromatid exchanges (SCE) were measured in mouse maternal and fetal cells between days 11 and 19 of gestation. Baseline levels of SCE did not vary as a function of gestational age in either the mother or fetus. Cyclophosphamide-induced SCE frequencies remained constant in maternal cells but declined dramatically in the fetus throughout the latter half of development. Because cyclophosphamide is a metabolically activated mutagen, a direct-acting drug, mitomycin C, was given on days 11 and 15 to determine if the decline in induced SCE levels seen with gestational results from alterations in activating enzymes. A similar decline in mitomycin C-induced SCE levels was noted in fetal tissues as a function of gestational age. Dose-response curves to cyclophosphamide performed on day 13 of gestation showed increases in SCE as a function of cyclophosphamide concentration in both the mother and the fetus. When mutagen-induced SCE levels were compared in different fetal organs, the direct-acting drugs (mitomycin C and daunomycin) were found to induce similar levels in all tissues. Cyclophosphamide, which is metabolically activated, induced higher SCE levels in fetal liver than in lung or gut. Whereas cyclophosphamide induced similar SCE levels in fetal and maternal cells on day 13 of gestation, daunomycin produced fetal SCE levels that were approximately 50% of maternal levels. Simultaneous measurement of the distribution of [14C]cyclophosphamide and [3H]daunomycin in maternal and fetal cells revealed that the lower SCE induction by daunomycin was probably due to decreased ability to cross the placental barrier. PMID:6933526

  6. Mutagen sensitivity as measured by induced chromatid breakage as a marker of cancer risk.

    PubMed

    Wu, Xifeng; Zheng, Yun-Ling; Hsu, T C

    2014-01-01

    Risk assessment is now recognized as a multidisciplinary process, extending beyond the scope of traditional epidemiologic methodology to include biological evaluation of interindividual differences in carcinogenic susceptibility. Modulation of environmental exposures by host genetic factors may explain much of the observed interindividual variation in susceptibility to carcinogenesis. These genetic factors include, but are not limited to, carcinogen metabolism and DNA repair capacity. This chapter describes a standardized method for the functional assessment of mutagen sensitivity. This in vitro assay measures the frequency of mutagen-induced breaks in the chromosomes of peripheral blood lymphocytes. Mutagen sensitivity assessed by this method has been shown to be a significant risk factor for tobacco-related maladies, especially those of the upper aerodigestive tract. Mutagen sensitivity may therefore be a useful member of a panel of susceptibility markers for defining high-risk subgroups for chemoprevention trials. This chapter describes methods for and discusses results from studies of mutagen sensitivity as measured by quantifying chromatid breaks induced by clastogenic agents, such as the γ-radiation mimetic DNA cross-linking agent bleomycin and chemicals that form so-called bulky DNA adducts, such as 4-nitroquinoline and the tobacco smoke constituent benzo[a]pyrene, in short-term cultured peripheral blood lymphocytes.

  7. Effects of chronic exposure to 2, 3, 7, 8,-tetrachlorodibenzo-p-dioxin on sister chromatid exchange levels in peripheral lymphocytes of the rhesus monkey

    SciTech Connect

    Lim, M.; Jacobson-Kram, D.; Bowman, R.E.; Williams, J.R.

    1987-01-01

    Frequencies of sister chromatid exchanges and chromosomal aberrations were examined in peripheral lymphocytes of Rhesus monkeys that had been fed a diet containing 25 parts per trillion 2,3,7,8-tetrachlorodibenzo-p-dioxin for a period of 4 years. When compared to non-exposed control animals, no significant differences were noted for either of these cytogenetic end points. In addition, there was not a significant difference in sister chromatid exchange response to a challenge dose of mitomycin C in cells from 2,3,7,8-tetrachlorodibenzo-p-dioxin exposed animals compared to controls. The results confirm the lack of genotoxic effects associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure.

  8. DNA single strand breakage, DNA adducts, and sister chromatid exchange in lymphocytes and phenanthrene and pyrene metabolites in urine of coke oven workers.

    PubMed Central

    Popp, W; Vahrenholz, C; Schell, C; Grimmer, G; Dettbarn, G; Kraus, R; Brauksiepe, A; Schmeling, B; Gutzeit, T; von Bülow, J; Norpoth, K

    1997-01-01

    OBJECTIVES: To investigate the specificity of biological monitoring variables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, 32P postlabelling assay, measurement of sister chromatid exchange) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (alkaline filter elution assay), sister chromatid exchange, and DNA adducts (32P postlabelling assay) in lymphocytes. Phenanthrene and pyrene metabolites were measured in 24 hour urine samples. 19 different PAHs (including benzo(a)pyrene, pyrene, and phenanthrene) were measured at the workplace by personal air monitoring. The GSTT1 activity in erythrocytes and lymphocyte subpopulations in blood was also measured. RESULTS: Concentrations of phenanthrene, pyrene, and benzo(a)pyrene in air correlated well with the concentration of total PAHs in air; they could be used for comparisons of different workplaces if the emission compositions were known. The measurement of phenanthrene metabolites in urine proved to be a better biological monitoring variable than the measurement of 1-hydroxypyrene. Significantly more DNA strand breaks in lymphocytes of coke oven workers were found (alkaline filter elution assay); the DNA adduct rate was not significantly increased in workers, but correlated with exposure to PAHs in a semiquantitative manner. The number of sister chromatid exchanges was lower in coke oven workers but this was not significant; thus counting sister chromatid exchanges was not a good variable for biomonitoring of coke oven workers. Also, indications for immunotoxic influences (changes in lymphocyte subpopulations) were found. CONCLUSIONS: The measurement of phenanthrene metabolites in urine seems to be a better biological monitoring variable for exposure to PAHs than

  9. Sister chromatid exchange analysis to monitor genotoxic chemicals. March 1978-July 1989 (A Bibliography from Pollution Abstracts). Report for March 1978-July 1989

    SciTech Connect

    Not Available

    1990-04-01

    This bibliography contains citations concerning the use of the sister chromatid exchange (SCE) analysis for toxicological studies. SCE analysis are very sensitive measures of genotoxic damage to chromosomes. SCE toxicological studies analyzing ionizing radiation, chromium compounds, styrene, paint thinner, mercury, cigarette smoke, coal dust, fuel oil, insecticides, ethylene oxide, diesel exhaust, and polychlorinated biphenyls are discussed. SCE studies using both human and animal tissue cultures are described. (Contains 150 citations fully indexed and including a title list.)

  10. Sister chromatid exchanges and micronuclei in lymphocytes of operating room personnel occupationally exposed to enfluorane and nitrous oxide.

    PubMed

    Pasquini, R; Scassellati-Sforzolini, G; Fatigoni, C; Marcarelli, M; Monarca, S; Donato, F; Cencetti, S; Cerami, F M

    2001-01-01

    The objective of this article is to assess whether occupational exposure to anesthetics increases genotoxic risk. We investigated two cytogenetic biomarkers, sister chromatid exchanges (SCE) and micronuclei (MN), in the peripheral blood lymphocytes of 46 anesthesiologists (24 men), working in operating rooms and mostly exposed to enfluorane and nitrous oxide, and 66 controls (35 men), not exposed to chemicals and living in the same area. Contrary to what was expected, a lower frequency of SCE was found in male anesthesiologists than in controls. Smoking status was found to be positively associated with SCE frequency in each group, while no relation to age was evident. On the contrary, MN frequency was significantly higher in female, but not male, anesthesiologists than in controls. Age and smoking status did not modify the association. No relationship between MN frequency and duration of employment was found in anesthesiologists. Smoking status and mean number of cigarettes smoked per day in smokers were not associated with MN frequency in either anesthesiologists or in controls. MN analysis seems to be a sensitive index of possible genotoxic effects of occupational exposure to anesthesiologists, and women appear to be more susceptible to these effects than men. PMID:11394710

  11. Effect of low /sup 60/Co dose rates on sister chromatid exchange incidence in the benthic worm. Neanthes arenaceodentata

    SciTech Connect

    Harrison, F.L.; Rice, D.W. Jr.

    1981-10-13

    The usefulness of sister chromatid exchange (SCE) induction as a measure of low-level radiation effect was examined in a benthic marine worm, Neanthes arenaceodentata. Larvae were exposed to /sup 60/Co radiation for 12 to 24 h at total doses ranging from 0.5 to 309 R and at dose rates from 0.04 to 13 R/h. Animals exposed at intermediate dose rates (0.5, 0.6, 1.25, 2.0, and 2.5 R/h) had SCE frequencies per chromosome about twice that of those receiving no radiation (controls), whereas those exposed at the higher dose rates (7.0 and 13 R/h) had SCE frequencies lower than the controls. Animals exposed at the lower dose rates (0.04 and 0.1 R/h) had lower SCE frequencies than those exposed at intermediate dose rates (and higher SCE frequencies than controls). The length of chromosome pair number one differed among metaphase spreads and was used as an index of chromosome condensation in a given metaphase. Because there is a possibility that chromosome morphology may affect the ability to resolve SCEs, morphology will be monitored in future studies. A preliminary experiment was performed to assess the effects of 2.2 and 11.5 R/h for 24 h on growth and development. Larvae observed at 6 and 17 d after irradiation did not have significantly different numbers of abnormal larvae or survival rates.

  12. Chromosome aberration and sister chromatid exchange tests in Chinese hamster ovary cells in vitro III: Results with 27 chemicals

    SciTech Connect

    Gulati, D.K. ); Witt, K.; Anderson, B.; Zeiger, E.; Shelby, M.D. )

    1989-01-01

    Twenty-seven chemicals previously tested in rodent carcinogenicity assays were tested for induction of chromosomal aberrations (ABS) and sister chromatid exchanges (SCE) in Chinese hamster ovary (CHO) cells as part of a larger analysis of the correlation between results of in vitro genetic toxicity assays and carcinogenicity bioassays. Chemicals were tested up to toxic doses with and without exogenous metabolic activation. Seventeen of the chemicals tested were carcinogens; only two of these were negative for both ABS and SCE. Of the eight noncarcinogens tested, four were negative for both endpoints and four gave a positive response for at least one endpoint. Of the remaining two chemicals, one, diallylphthalate, gave an equivocal response in the bioassay and a positive response in these CHO cell cytogenetics tests. The other chemical, 2,4-toluene diisocyanate, was tested for carcinogenicity as a mixture with the 2,6-isomer; the mixture was carinogenic, but the cytogenetic test results for the 2,4-isomer were negative. Experiments with unsynchronized CHO cells demonstrated that mean SCE frequency increased with increasing culture time, and this may have been a factor in the positive results obtained for five chemicals in the SCE test under conditions of delayed harvest.

  13. On the importance of DNA strand breaks as the first event to initiate sister chromatid exchange (SCE): experiments with restriction endonuclease BglI.

    PubMed

    Ortiz, T; Piñero, J; Cortés, F

    1996-11-01

    The exact molecular mechanism of sister chromatid exchange (SCE) is still unknown, despite the many reports dealing with this cytogenetic end point published in the last 40 years. One point to be investigated is the nature of the original lesion(s) in DNA leading to the production of SCE. Whereas, for chromosomal aberrations, the importance of DNA double-strand breaks has been well established, there is still controversy about the relative importance of strand breaks and base modifications for triggering the process of SCE formation. In the present paper, we have taken advantage of the ability of the restriction endonuclease BglI to induce SCE and have exploited the fact that preincubation with 2,3-butanedione results in the loss of BgiI ability to cut DNA, while it is still able to recognize its sequence in DNA and bind to it, to see whether this alone is enough to initiate SCE formation, or if a physical DNA double-strand break is required. Our results seem to support the necessity of DNA breaks for SCE production.

  14. Sister chromatid exchange assessment by chromosome orientation-fluorescence in situ hybridization on the bovine sex chromosomes and autosomes 16 and 26.

    PubMed

    Revay, T; King, W A

    2012-01-01

    Mammalian genome replication and maintenance are intimately coupled with the mechanisms that ensure cohesion between the resultant sister chromatids and the repair of DNA breaks. Although a sister chromatid exchange (SCE) is an error-free swapping of precisely matched and identical DNA strands, repetitive elements adjacent to the break site can act as alternative template sites and an unequal sister chromatid exchange can result, leading to structural variations and copy number change. Here we test the vulnerability for SCEs of the repeat-rich bovine Y chromosome in comparison with X, 16 and 26 chromosomes, using chromosome orientation-fluorescence in situ hybridization. The mean SCE rate of the Y chromosome (0.065 ± 0.029) was similar to that of BTA16 and BTA26 (0.065, 0.055), but was only approximately half of that of the X chromosome (0.142). As the chromosomal length affects the number of SCE events, we adjusted the SCE rates of the Y, 16, and 26 chromosomes to the length of the largest chromosome X resulting in very similar adjusted SCE (SCE(adj)) rates in all categories. Our results - based on 3 independent bulls - show that, although the cattle Y chromosome is a chest full of repeated elements, their presence and the documented activity of repeats in SCE formation does not manifest in significantly higher SCE(adj) rates and suggest the importance of the structural organization of the Y chromosome and the role of alternative mitotic DNA repair mechanisms.

  15. Effects on sister chromatid exchange frequency of aldehyde dehydrogenase 2 genotype and smoking in vinyl chloride workers.

    PubMed

    Wong, R H; Wang, J D; Hsieh, L L; Du, C L; Cheng, T J

    1998-12-01

    Vinyl chloride monomer (VCM) is a human carcinogen. However, the exact mechanism of carcinogenesis remains unclear. VCM may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferases (GSTs). Thus workers with inherited variant metabolic enzyme activities may have an altered risk of genotoxicity. This study was designed to investigate which risk factors might affect sister chromatid exchange (SCE) frequency in polyvinyl chloride (PVC) workers. Study subjects were 44 male workers from three PVC factories. Questionnaires were administered to obtain detailed histories of cigarette smoking, alcohol consumption, occupations, and medications. SCE frequency in peripheral lymphocytes was determined using a standardized method, and CYP2E1, GSTM1, GSTT1 and ALDH2 genotypes were identified by the polymerase chain reaction (PCR). Analysis revealed that smoking status and exposure to VCM were significantly associated with increased SCE frequency. The presence of ALDH2 1-2/2-2 genotypes was also significantly associated with an elevation of SCE frequency (9. 5 vs. 8.1, p<0.01). However, CYP2E1, GSTM1 or GSTT1 genotypes were not significantly associated with SCE frequency. When various genotypes were considered together, combination of CYP2E1 c1c2/c2c2 with ALDH2 1-2/2-2 showed an additive effect on SCE frequency. Similar results were also found for the combination of smoking with CYP2E1, or smoking with ALDH2. These results suggest that VCM workers with ALDH2 1-2/2-2 genotypes, who also smoke, may have increased risk of DNA damage.

  16. Chaetophractus villosus as a sentinel organism: Baseline values of mitotic index, chromosome aberrations and sister chromatid exchanges.

    PubMed

    Rossi, Luis Francisco; Luaces, Juan Pablo; Browne, Melanie; Chirino, Mónica Gabriela; Merani, María Susana; Mudry, Marta Dolores

    2016-01-15

    Sentinel species are useful tools for studying the deleterious effects of xenobiotics on wildlife. The large hairy armadillo (Chaetophractus villosus) is the most abundant and widely distributed mammal in Argentina. It is a long-lived, omnivorous, burrowing species, with fairly restricted home ranges. To evaluate the level of spontaneous genetic damage in this mammal, we determined the baseline values of several genotoxicity biomarkers. The study included 20 C. villosus adults of both sexes from eight pristine localities within its geographic distribution range. Genotoxicity analysis was performed on 72-h lymphocyte cultures, using mitomycin C as positive control. We obtained the baseline values of mitotic index (MI=10.52±0.30 metaphases/total cells, n=20), chromosome aberrations (CA=0.13±0.22, n=20), sister chromatid exchanges (SCE)=6.55±0.26, n=6) and replication index (RI=1.66, n=6). MI and CA did not show significant differences (P>0.05) among localities or between sexes. No significant differences in MI, CA, SCE, and RI (P>0.05) were found between values from the pristine localities and historical data. There were significant differences in CA, SCE, and RI (P<0.05) between lymphocyte cultures from pristine localities and those exposed to mitomycin C. We propose the large hairy armadillo as a sentinel organism for environmental biomonitoring of genotoxic chemicals due to its abundance, easy manipulation, well-known biology, the fact that it is usually exposed to different mixtures and concentrations of environmental contaminants, and the baseline values of genetic damage characterized by MI, CA, SCE and RI as biomarkers. PMID:26778508

  17. A novel frameshift mutation in BLM gene associated with high sister chromatid exchanges (SCE) in heterozygous family members.

    PubMed

    Ben Salah, Ghada; Hadj Salem, Ikhlas; Masmoudi, Abderrahmen; Kallabi, Fakhri; Turki, Hamida; Fakhfakh, Faiza; Ayadi, Hamadi; Kamoun, Hassen

    2014-11-01

    The Bloom syndrome (BS) is an autosomic recessive disorder comprising a wide range of abnormalities, including stunted growth, immunodeficiency, sun sensitivity and increased frequency of various types of cancer. Bloom syndrome cells display a high level of genetic instability, including a 10-fold increase in the sister chromatid exchanges (SCE) level. Bloom syndrome arises through mutations in both alleles of the BLM gene, which was identified as a member of the RecQ helicase family. In this study, we screened a Tunisian family with three BS patients. Cytogenetic analysis showed several chromosomal aberrations, and an approximately 14-fold elevated SCE frequency in BS cells. A significant increase in SCE frequency was observed in some family members but not reaching the BS patients values, leading to suggest that this could be due to the heterozygous profile. Microsatellite genotyping using four fluorescent dye-labeled microsatellite markers revealed evidence of linkage to BLM locus and the healthy members, sharing higher SCE frequency, showed heterozygous haplotypes as expected. Additionally, the direct BLM gene sequencing identified a novel homozygous frameshift mutation c.3617-3619delAA (p.K1207fsX9) in BS patients and a heterozygous BLM mutation in the family members with higher SCE frequency. Our findings suggest that this latter mutation likely leads to a reduced BLM activity explaining the homologous recombination repair defect and, therefore, the increase in SCE. Based on the present data, the screening of this mutation could contribute to the rapid diagnosis of BS. The genetic confirmation of the mutation in BLM gene provides crucial information for genetic counseling and prenatal diagnosis.

  18. Chaetophractus villosus as a sentinel organism: Baseline values of mitotic index, chromosome aberrations and sister chromatid exchanges.

    PubMed

    Rossi, Luis Francisco; Luaces, Juan Pablo; Browne, Melanie; Chirino, Mónica Gabriela; Merani, María Susana; Mudry, Marta Dolores

    2016-01-15

    Sentinel species are useful tools for studying the deleterious effects of xenobiotics on wildlife. The large hairy armadillo (Chaetophractus villosus) is the most abundant and widely distributed mammal in Argentina. It is a long-lived, omnivorous, burrowing species, with fairly restricted home ranges. To evaluate the level of spontaneous genetic damage in this mammal, we determined the baseline values of several genotoxicity biomarkers. The study included 20 C. villosus adults of both sexes from eight pristine localities within its geographic distribution range. Genotoxicity analysis was performed on 72-h lymphocyte cultures, using mitomycin C as positive control. We obtained the baseline values of mitotic index (MI=10.52±0.30 metaphases/total cells, n=20), chromosome aberrations (CA=0.13±0.22, n=20), sister chromatid exchanges (SCE)=6.55±0.26, n=6) and replication index (RI=1.66, n=6). MI and CA did not show significant differences (P>0.05) among localities or between sexes. No significant differences in MI, CA, SCE, and RI (P>0.05) were found between values from the pristine localities and historical data. There were significant differences in CA, SCE, and RI (P<0.05) between lymphocyte cultures from pristine localities and those exposed to mitomycin C. We propose the large hairy armadillo as a sentinel organism for environmental biomonitoring of genotoxic chemicals due to its abundance, easy manipulation, well-known biology, the fact that it is usually exposed to different mixtures and concentrations of environmental contaminants, and the baseline values of genetic damage characterized by MI, CA, SCE and RI as biomarkers.

  19. Induction of sister chromatid exchanges and inhibition of cellular proliferation in vitro. I. Caffeine

    SciTech Connect

    Guglielmi, G.E.; Vogt, T.F.; Tice, R.R.

    1982-01-01

    While many agents have been examined for their ability to induce SCE's, complete dose-response information has often been lacking. We have reexamined the ability of one such compound - caffeine - to induce SCEs and also to inhibit cellular proliferation in human peripheral lymphocytes in vitro. An acute exposure to caffeine prior to the DNA synthetic period did not affect either SCE frequency or the rate of cellular proliferation. Chronic exposure to caffeine throughout the culture period lead to both a dose-dependent increase in SCEs (SCE/sub d/ or doubling dose = 2.4 mM; SCE/sub 10/ or the dose capable of inducing 10 SCE = 1.4 mM) and a dose-dependent inhibition of cellular proliferation (IC/sub 50/ or the 50% inhibition concentration = 2.6 mM). The relative proportion of first generation metaphase cells, an assessment of proliferative inhibiton, increased linearly with increasing caffeine concentrations. However, SCE frequency increased nonlinearly over the same range of caffeine concentrations. Examination of the ratio of nonsymmetrical to symmetrical SCEs in third generation metaphase cells indicated that caffeine induced SCEs in equal frequency in each of three successive generations. The dependency of SCE induction and cellular proliferative inhibition on caffeine's presence during the DNA synthetic period suggests that caffeine may act as an antimetabolite in normal human cells.

  20. Genotoxic effects of a particular mixture of acetamiprid and alpha-cypermethrin on chromosome aberration, sister chromatid exchange, and micronucleus formation in human peripheral blood lymphocytes.

    PubMed

    Kocaman, Ayşe Yavuz; Topaktaş, Mehmet

    2010-04-01

    The genotoxic effects of a particular mixture of acetamiprid (Acm, neonicotinoid insecticide) and alpha-cypermethrin (alpha-cyp, pyrethroid insecticide) on human peripheral lymphocytes were examined in vitro by chromosomal aberrations (CAs), sister chromatid exchange (SCE), and micronucleus (MN) tests. The human peripheral lymphocytes were treated with 12.5 + 2.5, 15 + 5, 17.5 + 7.5, and 20 + 10 microg/mL of Acm+alpha-cyp, respectively, for 24 and 48 h. The mixture of Acm+alpha-cyp induced the CAs and SCEs at all concentrations and treatment times when compared with both the control and solvent control and these increases were concentration-dependent in both treatment times. MN formation was significantly induced at 12.5 + 2.5, 15 + 5, 17.5 + 7.5, microg/mL of Acm+alpha-cyp when compared with both controls although these increases were not concentration-dependent. Binuclear cells could not be detected sufficiently in the highest concentration of the mixture (20 + 10 microg/mL) for both the 24- and 48-h treatment times. Mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) significantly decreased because of the cytotoxic and cytostatic effects of the mixture, at all concentrations for two treatment periods. Significant decreases in MI and PI were concentration dependent at both treatment times. The decrease in NDI was also concentration-dependent at 48-h treatment period. In general, Acm+alpha-cyp inhibited nuclear division more than positive control, mitomycin C (MMC) and showed a higher cytostatic effect than MMC. Furthermore, in this article, the results of combined effects of Acm+alpha-cyp were compared with the results of single effects of Acm or alpha-cyp (Kocaman and Topaktas,2007,2009, respectively). In conclusion, the particular mixture of Acm+alpha-cyp synergistically induced the genotoxicity/cytotoxicity in human peripheral blood lymphocytes.

  1. Measurement of chromosomal aberrations, sister chromatid exchange, hprt mutations, and DNA adducts in peripheral lymphocytes of human populations at increased risk for cancer

    SciTech Connect

    Jacobson-Kram, D. |; Albertini, R.J.; Branda, R.F.

    1993-10-01

    We have measured various indicators of DNA damage in peripheral lymphocytes of human populations potentially at increased risk for cancer. Sister chromatid exchanges (SCE) and polycyclic aromatic hydrocarbon (PAH)-DNA adducts were evaluated in a group of firefighters; chromosomal aberrations and hprt mutations were evaluated in a group of cancer patients undergoing radioimmunoglobulin therapy (RIT); SCE and acrolein-modified DNA were measured in cancer chemotherapy, patients and in pharmacists preparing chemotherapy prescriptions; and SCE and PAH-DNA adducts are being measured in U.S. army troops stationed in Kuwait. Results indicate that both SCE and PAH-DNA adduct levels were not elevated in firefighters, but that other factors such as smoking status and race were risk factors for increased SCE and PAH-DNA adducts. RIT was found to increase background rates of chromosome-type aberrations and frequencies of hprt mutations and there was a strong correlation between levels of therapy-induced chromosome damage sustained in vivo and in vitro sensitivity to radiation-induced chromosome damage. Peripheral blood lymphocytes of cancer patients treated with cyclophosphamide showed higher levels of SCE and had a higher incidence of acrolein adducts in DNA. Lymphocytes from pharmacists preparing antineoplastic drugs were found to acquire increased in vitro sensitivity to SCE induction by phosphoramide mustard with increased lifetime duration of drug handling. A prospective, longitudinal study was performed to identify environmental factors that modulate genetic damage in breast cancer patients. Women with benign breast masses and no apparent disease served as controls. Mutant frequency, cloning efficiency, and chromosomal aberration frequency did not differ significantly among the three groups. 10 refs., 2 figs., 4 tabs.

  2. Chromosomal aberrations and sister chromatid exchanges in individuals exposed to arsenic through drinking water in West Bengal, India.

    PubMed

    Mahata, J; Basu, A; Ghoshal, S; Sarkar, J N; Roy, A K; Poddar, G; Nandy, A K; Banerjee, A; Ray, K; Natarajan, A T; Nilsson, R; Giri, A K

    2003-01-10

    Arsenic contamination in groundwater has become a worldwide problem. Currently an unprecedented number of people in West Bengal, India and Bangladesh are exposed to the ubiquitous toxicant via drinking water in exposure levels far exceeding the maximum recommended limit laid down by WHO. This arsenic epidemic has devastated nine districts of West Bengal encompassing an area of 38,865 km(2) leading to various clinical manifestations of chronic arsenicosis. We conducted a human bio-monitoring study using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as end points to explore the cytogenetic effects of chronic arsenic toxicity in the population of North 24 Parganas, one of the arsenic affected districts in West Bengal. Study participants included 59 individuals residing in this district where the mean level (+/-S.E.) of arsenic in drinking water (microg/l) was 211.70+/-15.28. As age matched controls with similar socio-economic status we selected 36 healthy, asymptomatic individuals residing in two unaffected districts--Midnapur and Howrah where the mean arsenic content of water (microg/l) was 6.35+/-0.45. Exposure was assessed by standardized questionnaires and by detecting the levels of arsenic in drinking water, nails, hair and urine samples. In the exposed group the mean arsenic concentrations in nails (microg/g), hair (microg/g) and urine (microg/l) samples were 9.04+/-0.78, 5.63+/-0.38 and 140.52+/-8.82, respectively, which were significantly high (P<0.01) compared to the corresponding control values of 0.44+/-0.03, 0.30+/-0.02 and 5.91+/-0.49, respectively. Elevated mean values (P<0.01) of the percentage of aberrant cells (8.08%) and SCEs per cell (7.26) were also observed in the exposed individuals in comparison to controls (1.96% and 5.95, respectively). The enhanced rates of CAs and SCEs among the residents of North 24 Parganas are indicative of the cytogenetic damage due to long term exposure to arsenic through consumption of contaminated

  3. Replication-Dependent Sister Chromatid Recombination in Rad1 Mutants of Saccharomyces Cerevisiae

    PubMed Central

    Kadyk, L. C.; Hartwell, L. H.

    1993-01-01

    Homolog recombination and unequal sister chromatid recombination were monitored in rad1-1/rad1-1 diploid yeast cells deficient for excision repair, and in control cells, RAD1/rad1-1, after exposure to UV irradiation. In a rad1-1/rad1-1 diploid, UV irradiation stimulated much more sister chromatid recombination relative to homolog recombination when cells were irradiated in the G(1) or the G(2) phases of the cell cycle than was observed in RAD1/rad1-1 cells. Since sister chromatids are not present during G(1), this result suggested that unexcised lesions can stimulate sister chromatid recombination events during or subsequent to DNA replication. The results of mating rescue experiments suggest that unexcised UV dimers do not stimulate sister chromatid recombination during the G(2) phase, but only when they are present during DNA replication. We propose that there are two types of sister chromatid recombination in yeast. In the first type, unexcised UV dimers and other bulky lesions induce sister chromatid recombination during DNA replication as a mechanism to bypass lesions obstructing the passage of DNA polymerase, and this type is analogous to the type of sister chromatid exchange commonly observed cytologically in mammalian cells. In the second type, strand scissions created by X-irradiation or the excision of damaged bases create recombinogenic sites that result in sister chromatid recombination directly in G(2). Further support for the existence of two types of sister chromatid recombination is the fact that events induced in rad1-1/rad1-1 were due almost entirely to gene conversion, whereas those in RAD1/rad1-1 cells were due to a mixture of gene conversion and reciprocal recombination. PMID:8454200

  4. Use of a ring chromosome and pulsed-field gels to study interhomolog recombination, double-strand DNA breaks and sister-chromatid exchange in yeast

    SciTech Connect

    Game, J.C. ); Sitney, K.C.; Cook, V.E.; Mortimer, R.K. )

    1989-12-01

    The authors describe a system that uses pulsed-field gels for the physical detection of recombinant DNA molecules, double-strand DNA breaks (DSB) and sister-chromatid exchange in the yeast Saccharomyces cerevisiae. The system makes use of a circular variant of chromosome II (Chr. III). Meiotic recombination between this ring chromosome and a linear homolog produces new molecules of sizes distinguishable on gels from either parental molecule. They demonstrate that these recombinant molecules are not present either in strains with two linear Chr. III molecules or in rad50 mutants, which are defective in meiotic recombination. In conjunction with the molecular endpoints. They present data on the timing of commitment to meiotic recombination scored genetically. They have used x-rays to linearize circular Chr. III, both to develop a sensitive method for measuring frequency of DSB and as a means of detecting double-size circles originating in part from sister-chromatid exchange, which they find to be frequent during meiosis.

  5. Activity of nitro-polynuclear aromatic hydrocarbons in the sister chromatid exchange assay with and without metabolic activation. [Hamsters

    SciTech Connect

    Nachtman, J.P.; Wolff, S.

    1982-01-01

    Nitro-polynuclear aromatic hydrocarbons are found in diesel particulates.These compounds are potent mutagens in the Ames test. To determine whether nitro-polynuclear aromatic hydrocarbons are active in a mammalian cell assay, 1-nitropyrene, 1,8-dinitropyrene, 2-nitrofluorene, and 4-nitrobiphenyl were incubated with cultures of Chinese hamster ovary cells. The frequency of sister chromatic exchange (SCE) was measured in the presence and absence of rat liver S-9 mix. The addition of S-9 mix resulted in a large increase in the SCEs induced by all four compounds.

  6. Sister-chromatid exchanges and cell-cycle kinetics in the lymphocytes of workers occupationally exposed to a chemical mixture in the tyre industry.

    PubMed

    Sasiadek, M

    1993-08-01

    Cytogenetic studies of clinically healthy workers employed in the rubber industry showed an increase in chromosome aberrations (CAs), sister-chromatid exchanges (SCEs) and a decrease in proliferation indices (PIs). The aim of the present study was to establish, using the SCE and PI tests, genotoxic effects of hazardous chemicals in the rubber industry. An increase in mean SCEs in the lymphocytes of vulcanizers as compared to controls was observed. Since the PI in the exposed group was insignificantly decreased as compared to the controls, it could be concluded that the SCE test is the most sensitive cytogenetic test for the detection of a genotoxic effect of chemicals in the rubber industry. There was no evidence in the present study that the genotoxic effect of chemicals in the rubber industry was enhanced by cigarette smoking. PMID:7688857

  7. Mutagenicity studies on herring gulls from different locations on the Great Lakes. I. Sister chromatid exchange rates in herring-gull embryos.

    PubMed

    Ellenton, J A; McPherson, M F

    1983-01-01

    Unincubated herring-gull (Larus argentatus) eggs were collected from five colonies on the Great Lakes Basin and from one relatively pollutant-clean colony on the Atlantic coast. Eggs were incubated at 38 degrees C with 55% relative humidity, and sister chromatid exchange (SCE) levels were measured in 7-d embryos. For all of the colonies, the average SCE/chromosome frequency ranged from 0.069 to 0.101; however, no significant differences were found. Organochlorine analysis was carried out on egg homogenates for each colony, to determine the levels of several contaminants. There were no relationships found between any of the contaminant levels and the SCE frequencies. The study indicates that either the contaminants present in the herring-gull eggs are not having any genetic effects on the embryos or, alternatively, that there may be genetic damage that measurement of SCEs in the 7-d embryo is unable to detect. PMID:6655738

  8. G2 chromatid aberrations: Kinetics and possible mechanisms

    SciTech Connect

    Bryant, P.E.; Slijepcevic, P. )

    1993-01-01

    Chromatid breaks and exchanges are induced by radiation in G2 mammalian cells. Breaks are at a maximum number at about 30 min after irradiation and decrease apparently exponentially with time between irradiation and sampling. Few breaks are observed immediately following exposure, probably as a result of selection of mitotic cells where chromosomes are condensed and there is consequently a lack of time for expression of damage. The change in frequency of breaks with time, from 30 min after radiation exposure and onwards, can be interpreted in two possible ways: either in terms of a repair process or in terms of a change in radiosensitivity through G2. However, the results with an inhibitor of repair of DNA double-strand breaks (ara A) and with [open quotes]transient hypothermia[close quotes] which extends the G2 phase, argue for an interpretation based on rejoining of chromatid breaks, possibly reflecting the repair of a subclass of dsb. Data from experiments with irradiated and restriction endonuclease treated radiosensitive mutant rodent lines indicate that enhanced levels of conversion of dsb into chromosomal aberrations may be largely independent of repair rates of bulk dsb. In CHO cells and in human lymphocytes exchanges initially increase rapidly with time and then remain at a constant frequency, supporting the notion of a uniform chromosomal radiosensitivity throughout most of G2 and providing further evidence that the mechanism for misjoining broken chromatids (leading to exchanges) is different from that for rejoining of chromatid breaks. Ratios of breaks to exchanges were found to vary in different cell lines and at different times during treatment with inhibitors or at altered temperatures, possibly (in different cell lines) indicating different levels of enzymes involved in misjoining, but suggesting that the mechanisms of chromosomal rejoining and misjoining are independent, at least to some degree. 19 refs., 11 figs., 1 tab.

  9. Effects of caffeine and inhibitors of DNA synthesis on chromatid-type aberrations induced by acetaldehyde in root-tip cells.

    PubMed

    Cortés, F; Mateos, S; Ortiz, T; Piñero, J

    1987-10-01

    Root-tip cells of Allium cepa were exposed to acetaldehyde (AA) and post-treated with caffeine and 3 inhibitors of DNA synthesis, namely hydroxyurea (HU), 5-fluorodeoxyuridine (FdUrd), and arabinofuranosylcytosine (araC). Caffeine strongly potentiated the frequency of chromatid-type aberrations when given immediately after the AA treatment or as a 5-h treatment starting 10 h before the addition of colchicine. In contrast, no enhancement was observed when caffeine was present for the last 2.5 h, simultaneously with colchicine. The inhibitors of DNA synthesis were given following this last schedule. Both HU and FdUrd clearly enhanced the yield of AA-induced chromatid aberrations, while no enhancement of chromosome damage was observed after exposure to araC.

  10. Lower frequency of sister chromatid exchanges and altered frequency of HLA B-region alleles among individuals with sporadic dysplastic nevi.

    PubMed

    Illeni, M T; Rovini, D; Di Lernia, M; Cascinelli, N; Ghidoni, A

    1997-01-01

    Sister chromatid exchanges (SCE) were analyzed in peripheral blood lymphocytes of 24 individuals, following diagnosis, and prior to surgical removal, of a sporadic dysplastic nevus (DN). Lower SCE values and variability were found in 23 sporadic DN individuals compared with controls (2.52 +/- 0.12 and 3.76 +/- 0.22 SCE/cell, respectively). These DN individuals, contrarily to healthy controls and some types of tumor patients whose cells are hypersensitive to mutagenic agents, did not show increased SCE rates as a consequence of cigarette smoking, alcohol consumption and diagnostic radiation treatments. These observations are in contrast with clinical evidence that similar lesions are both markers or risk and precursors of malignancy in individuals with multiple nevi, affected by the dysplastic nevus syndrome (DNS) or belonging to FMM (familial malignant melanoma) families. Three HLA class I alleles out of 72 tested were found more frequently in sporadic DN individuals compared with controls: B37 (p < 0.05), B52 (p < 0.01) and B70 (p < 0.01). Whether the greater chromosomal stability (as shown by the SCE analysis), and/or the altered frequency of some HLA alleles could influence the chance of developing cutaneous malignancy in DN individuals is yet to be evaluated.

  11. Association of Polymorphisms of Phase I Metabolizing Genes with Sister Chromatid Exchanges in Occupational Workers Exposed to Toluene Used in Paint Thinners

    PubMed Central

    Priya, Kanu; Yadav, Anita; Kumar, Neeraj; Gulati, Sachin; Aggarwal, Neeraj; Gupta, Ranjan

    2015-01-01

    This study investigated genetic damage in paint workers mainly exposed to toluene as it is a major solvent used in paint thinners. Sister chromatid exchange (SCE) assay was used as biomarker of genotoxicity. Blood samples were collected from 30 paint workers and 30 control subjects matched with respect to age and other confounding factors except for exposure to toluene. SCE frequency was found to be significantly higher in paint workers (4.81 ± 0.92) as compared to control individuals (1.73 ± 0.54) (p < 0.05). We also investigated influence of polymorphisms of CYP2E1 and CYP1A1m2 genes on SCE frequency. Our results showed that there was significant increase in frequencies of SCE among the mutant genotypes of CYP2E1 and CYP1A1m2 as compared to wild genotypes. Our study indicated that long term exposure of toluene can increase genotoxic risk in paint workers. PMID:26688756

  12. Genotoxic monitoring and benzene exposure assessment of gasoline station workers in metropolitan Bangkok: sister chromatid exchange (SCE) and urinary trans, trans-muconic acid (t,t-MA).

    PubMed

    Tunsaringkarn, Tanasorn; Suwansaksri, Jamsai; Soogarun, Suphan; Siriwong, Wattasit; Rungsiyothin, Anusorn; Zapuang, Kalaya; Robson, Mark

    2011-01-01

    Early warning of the potential of mutagens or carcinogens caused by benzene exposure that might occur in gasoline station workers can be achieved by examining 2 major biomarkers: sister chromatid exchange (SCE) and trans, trans-muconic acid (t,t-MA), a urinary metabolite of benzene. The main objective of this study was to assess benzene exposure and monitor the genotoxic effect of gasoline station workers in Bangkok, Thailand. Blood and urine samples were collected from 33 gasoline station workers, working in Pathumwan district area, central Bangkok, Thailand, for SCE and t,t-MA analysis, from April to June 2009. Control samples were collected from 30 office workers and students in the same area at the same period. Our results indicated significantly higher frequencies of SCE in gasoline exposed workers were than in controls (p<0.01), independent of gender. Urinary t,t-MA and t,t-MA/creatinine levels of gasoline exposed workers were also significantly higher than the control groups (p<0.05) were significantly higher in women than men workers (p<0.01). Calculated chromosomal damage relative risk (RR) of gasoline station workers was 3.00 (95% CI = 1.81 - 4.98, p<0.001) compared to controls. The gasoline exposed workers had potentially higher risk of chromosomal damage and cancer development because of direct contact to benzene.

  13. Variation in the human lymphocyte sister chromatid exchange frequency as a function of time: results of daily and twice-weekly sampling

    SciTech Connect

    Tucker, J.D.; Christensen, M.L.; Strout, C.L.; McGee, K.A.; Carrano, A.V.

    1987-01-01

    The variation in lymphocyte sister chromatid exchange (SCE) frequency was investigated in healthy nonsmokers who were not taking any medication. Two separate studies were undertaken. In the first, blood was drawn from four women twice a week for 8 weeks. These donors recorded the onset and termination of menstruation and times of illness. In the second study, blood was obtained from two women and two men for 5 consecutive days on two separate occasions initiated 14 days apart. Analysis of the mean SCE frequencies in each study indicated that significant temporal variation occurred in each donor, and that more variation occurred in the longer study. Some of the variation was found to be associated with the menstrual cycle. In the daily study, most of the variation appeared to be random, but occasional day-to-day changes occurred that were greater than those expected by chance. To determine how well a single SCE sample estimated the pooled mean for each donor in each study, the authors calculated the number of samples that encompassed that donor's pooled mean within 1 or more standard errors. For both studies, about 75% of the samples encompassed the pooled mean within 2 standard errors. An analysis of high-frequency cells (HFCs) was also undertaken. The results for each study indicate that the proportion of HFCs, compared with the use of Fisher's Exact test, is significantly more constant than the means, which were compared by using the t-test. These results coupled with our previous work suggest that HFC analysis may be the method of choice when analyzing data from human population studies.

  14. XRCC1, CYP2E1 and ALDH2 genetic polymorphisms and sister chromatid exchange frequency alterations amongst vinyl chloride monomer-exposed polyvinyl chloride workers.

    PubMed

    Wong, Ruey-Hong; Wang, Jung-Der; Hsieh, Ling-Ling; Cheng, Tsun-Jen

    2003-08-01

    Vinyl chloride monomer (VCM) is a known human carcinogen, which may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2), and glutathione S-transferase T1 (GSTT1). A DNA-repair gene, X-ray repair cross-complementing group 1 ( XRCC1, exon 10), may also be implicated in the process of VCM-related carcinogenesis. Thus, VCM-exposed workers with inherited susceptible metabolic and DNA-repair genotypes may experience an increased risk of genotoxiciy. This study was designed to investigate whether metabolic and DNA-repair genotypes affected sister chromatid exchange (SCE) frequency in occupationally VCM-exposed workers from polyvinyl chloride (PVC) manufacturing plants. Study subjects comprised 61 male workers having experienced VCM exposure, and 29 male controls. Questionnaires were administered to obtain detailed histories of cigarette-smoking habits, alcohol consumption behavior, and occupation. The frequency of SCE in peripheral lymphocytes was determined using a standardized method, and genotypes of CYP2E1, ALDH2, GSTT1 and XRCC1 were identified by the polymerase chain reaction (PCR) procedure. Our results demonstrated that smoking, age and VCM exposure and XRCC1 ( P=0.03), CYP2E1 ( P=0.04), and ALDH2 ( P=0.08) were significantly associated with an increased SCE frequency. Further analysis of gene combinations, including CYP2E1, ALDH2 and XRCC1, revealed an increased trend for these genotypes to influence SCE frequencies for the low VCM-exposure group ( P<0.01), but not so for the high VCM-exposure group ( P=0.29) or for controls ( P=0.49). These results suggest that workers with susceptible metabolic and DNA-repair genotypes, may experience an increased risk of DNA damage elicited by VCM exposure.

  15. Increased frequency of chromosomal aberrations and sister chromatid exchanges in peripheral lymphocytes of radiology technicians chronically exposed to low levels of ionizing radiations.

    PubMed

    Santovito, Alfredo; Cervella, Piero; Delpero, Massimiliano

    2014-01-01

    Chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) frequencies were estimated in peripheral lymphocytes from 21 radiology technicians, and from 21 non-exposed control subjects. We exclusively considered individuals who neither smoke nor consume drugs or alcohol for a period of at least two years prior to the analysis. Significant differences were found between exposed and controls in terms of SCEs and CAs frequencies. Technicians showed a significant higher number of high-frequency individuals (HFIs) with respect to the control group. Nevertheless, the mean frequency of SCEs observed among technician HFIs did not significantly differ with respect to that observed among control HFIs. Vice versa, the non-HFIs belonging to technicians group showed a statistically higher difference in the SCEs/NSM value with respect to the non-HFIs belonging to control group. Since the differences in the SCEs frequencies between the two groups are due to non-HFIs, our results seem to indicate a general genotoxic effect of the IR, not affected by HFIs. Among technicians, the level of chromosome damage correlated neither with years of radiation exposure nor with the age of the subjects. Vice versa, in the control group, a positive correlation was found between the number of SCEs and age. In both samples the gender status did not influence the frequencies of CAs and SCEs. Our results suggest that chronic long-term exposure to low doses of ionizing radiation could increase the CAs and SCEs frequencies. This study reinforces the relevance of the biomonitoring of hospital workers chronically exposed to ionizing radiation.

  16. Influence of smoking behavior in relation to plasma retinol and alpha-tocopherol on sister chromatid exchanges in human peripheral blood lymphocytes.

    PubMed

    Hageman, G; van den Oetelaar, A; Welle, I; Beurskens-Comuth, P; Kleinjans, J

    1995-01-01

    The present study was undertaken to evaluate the contribution of various individual characteristics and lifestyle factors on sister chromatid exchange (SCE) frequencies in human peripheral blood lymphocytes (PBLs). These also included associations between plasma retinol and alpha-tocopherol and SCE frequencies. The study population consisted of 50 healthy, smoking and nonsmoking, male and female volunteers, ages 22-49. SCE frequencies in PBLs were significantly higher in smokers than in nonsmokers. SCE frequencies correlated with variables of smoking habits and history, with the number of pack-years smoked correlating most strongly (r = 0.501; P < 0.001). Inverse but nonsignificant correlations were observed between plasma retinol and alpha-tocopherol levels and SCE frequencies in PBLs. In addition, with the use of multiple regression analysis, significant associations were found with age and possible occupational exposure after adjustment for smoking habits (r2 = 0.428; P = 0.0001). For males (n = 20), SCE frequencies were found to be associated significantly with the number of cigarettes smoked per day and possible occupational exposure (r2 = 0.485; P < 0.01). SCE frequencies in PBLs of females (n = 30) were associated positively with the number of pack-years smoked and age, and significantly inversely correlated with plasma alpha-tocopherol concentrations (r2 = 0.586; P = 0.0001). After exclusion of possible occupationally exposed persons (n = 8) from the study population and adjustment for the effects of age and smoking behavior, a weak inverse correlation was found between plasma alpha-tocopherol and SCE frequencies (r = -0.286; P = 0.0732).(ABSTRACT TRUNCATED AT 250 WORDS)

  17. The structure-function relationships of nitrofluorenes and nitrofluorenones in the Salmonella mutagenicity and CHO sister-chromatid exchange assays.

    PubMed

    Kitchin, R M; Bechtold, W E; Brooks, A L

    1988-11-01

    Nitrofluorenes and nitrofluorenones are bacterial mutagens and are detected in a variety of environmental pollution sources. We tested a series of nitrosubstituted fluorenes and fluorenones for their genotoxicity using both Salmonella bacteria and Chinese hamster ovary (CHO) cells to determine if structure-function relationships observed in bacteria for mutation induction are similar to those for mutations and SCE induction in mammalian (CHO) cells. The compounds studied were 2-nitrofluorene (2-NF), 2,7-dinitrofluorene (2,7-DNF), 3-nitrofluorenone (3-NFone), 2-nitrofluorenone (2-NFone), 2,7-dinitrofluorenone (2,7-DNFone), 2,4,7-trinitrofluorenone (2,4,7-TNFone), and 2,4,5,7-tetranitrofluorenone (2,4,5,7-TNFone). In bacteria, the presence of carbonyl group to convert mono-nitrofluorenes to nitrofluorenones and the addition of a second nitro group to either mono-nitrofluorene or fluorenone to form the dinitro compounds increased mutagenic activity in the Ames test. Location of the nitro group relative to the carbonyl group was important in enhancing mutagenic activity as 2-nitrofluorenone was more mutagenic than 3-nitrofluorenone. In CHO cells, the di-, tri- and tetra-nitrofluorenones were cytotoxic and delayed the progression of CHO cells through the cell cycle. The degree of the cytotoxicity could be decreased by the addition of S9. None of the compounds produced mutations when tested in the CHO/HGPRT mutation assay with the addition of S9. Nonetheless, the current study did show that these compounds, both with and without the activation by S9, can interact with the DNA and produce SCE in CHO cells. The addition of a carbonyl group had no influence on SCE frequency since both 2-nitrofluorene and 2-nitrofluorenone induced a similar frequency of SCE either with or without S9. Additional nitro groups, forming di-, tri- or tetra-nitrofluorenones, increased the frequency of SCE induced, especially when tested with S9 which limits cytotoxicity. The addition of a single

  18. Induction of micronuclei and sister chromatid exchanges by polycyclic and N-heterocyclic aromatic hydrocarbons in cultured human lymphocytes

    SciTech Connect

    Warshawsky, D.; Livingston, G.K.; LaDow, K.

    1995-12-31

    Many natural environments are contaminated with carcinogenic polycyclic aromatic hydrocarbons (PAHs) and N-heterocyclic aromatic hydrocarbons (NHAs) as complex mixtures of coal tar, petroleum, and shale oil. These potentially hazardous substances are prevalent at many former tar production and coal gasification sites. Three polycyclic [benzo(a)pyrene (BaP), benz(a)anthracene (BAA), and 7, 12-dimethylbenz(a)anthracene (DMBA)] and two N-heterocyclic [7H-dibenzo(c,g)carbazole (DBC), and dibenz(a,j)acridine (DBA)] aromatic hydrocarbons were analyzed for cytotoxic and genotoxic effects on human lymphocytes. All of these polyaromatic compounds are normally present in the environment, except for DMBA. Lymphocytes from healthy donors were isolated from whole blood. The 5-ring polycyclic aromatic BaP consistently induced micronuclei in a linear dose-dependent manner with doses from 0.1-10.0 {mu}g/ml, whereas the 4-ring compounds (BAA and DMBA) had no effect on the induction of micronuclei above controls except at 5 and 10 {mu}g/ml. Of the two N-heterocyclic compounds DBC produced a significant increase in micronuclei in lymphocytes, but the dose response tended to plateau above 0.1 {mu}g/ml. DBA showed an effect on the frequency of micronuclei above controls only at high doses of 5 and 10 {mu}g/ml. The average background frequency of micronuclei for 7 lymphocyte donors averaged 3.1 per 1,000 stimulated cells, whereas the average frequency of micronuclei at 10 {mu}g/ml BaP was 36.8 per 1,000 stimulated cells. The lowest effective dose in 2 donors for BaP occurred at 0.1 {mu}g/ml. 61 refs., 2 figs., 6 tabs.

  19. Biomonitoring of exposure to urban air pollutants: analysis of sister chromatid exchanges and DNA lesions in peripheral lymphocytes of traffic policemen.

    PubMed

    Carere, A; Andreoli, C; Galati, R; Leopardi, P; Marcon, F; Rosati, M V; Rossi, S; Tomei, F; Verdina, A; Zijno, A; Crebelli, R

    2002-07-25

    In order to elucidate the health effects of occupational exposure to traffic fumes, a few biomarkers of early genetic effect were investigated in Rome traffic policemen. One hundred and ninety healthy subjects engaged in traffic control (133 subjects) or in office work (57 subjects) participated the study. For all subjects, detailed information on smoking habits and other potential confounders were recorded by questionnaires. Average exposure of the study groups to benzene and other aromatic hydrocarbons was evaluated in a parallel exposure survey. All workers were genotyped for the following metabolic polymorphisms: CYP1A1 (m1, m2, and m4 variants), CYP2E1 (PstI and RsaI), NQO1 (Hinf1), GSTM1 and GSTT1 (null variants). In this paper, the results of the analysis of sister chromatid exchanges (SCE) in peripheral lymphocytes, and DNA damage by alkaline (pH 13) comet assay in mononuclear blood cells are reported. No statistically significant difference in the frequency of SCE or high frequency cells (HFC) was observed between traffic wardens and office workers (controls), despite the significantly higher exposure to benzene of the former (average group exposure 9.5 versus 3.8microg/m(3), 7h TWA). Conversely, both SCE per cell and HFC were highly significantly (P<0.001) increased in smokers compared to nonsmokers, showing a significant correlation (P<0.001) with the number of cigarettes per day. Multiple regression analyses of data, with metabolic polymorphisms, smoking habits, alcohol consumption, age, gender, and family history of cancer as independent variables, showed that smoking habits, and possibly the CYP2E1 variant genotypes, were the main factors explaining the variance of both SCE and HFC. Within smokers, an association of borderline significance between the CYP1A1 variant genotypes and increased SCE (P=0.050) and HFC (P=0.090) was found. This effect was mainly observed in light smokers (<15 cigarettes per day). The analysis of DNA damage by comet assay did

  20. Sister chromatid exchange and micronucleus frequency in human lymphocytes of 1,650 subjects in an Italian population: II. Contribution of sex, age, and lifestyle.

    PubMed

    Barale, R; Chelotti, L; Davini, T; Del Ry, S; Andreassi, M G; Ballardin, M; Bulleri, M; He, J; Baldacci, S; Di Pede, F; Gemignani, F; Landi, S

    1998-01-01

    Sister chromatid exchange (SCE) and micronuclei (MN) analysis was carried out on 1,650 healthy individuals living in Pisa and in two nearby small cities, Cascina and Navacchio (Ca-Na). The effect of smoking on SCEs was linearly correlated with the number of cigarettes per day, and an increase of 7.3% SCEs was detectable for as few cigarettes as 1-10/day. Ex-smokers showed intermediate mean values of SCEs (8.09 +/- 1.88) in comparison with never smokers (7.54 +/- 1.61) and current smokers (8.45 +/- 1.94). Mean values of SCEs of ex-smokers decreased linearly with time of smoking cessation, reaching the mean values of never smokers within 8 years. The extent of SCE decrease was inversely proportional to the number of cigarettes previously smoked. No interaction between smoking habits and coffee or alcohol drinking on SCEs was observed. A borderline (P = 0.053) increase in mean SCE values in coffee drinkers (more than 3 cups/day) was found. The age effect on SCEs was remarkable in Ca-Na, but not in Pisa donors. Job type was not associated with significant modification of mean values of SCEs. Multiple logistic regression analysis revealed a statistically significant association between the proportion of high frequency cells (HCF) outliers and coffee consumption. Age and sex appeared to be by far the most important variables associated with modifications in MN frequency, which increased by 0.04 per thousand and 0.02 per thousand per year in males and females, respectively. Children and young donors (age < or = 40 years) showed lower MN frequency regardless of sex, whereas sex appeared to determine a significantly higher increase of MN only in females older than 40 years. In contrast, in males the MN rate by age tended to level off after the age of 30-50. MN frequencies of Pisa blue- and white-collar workers were statistically significantly higher than in students (+0.71 and +0.55 per thousand, respectively). Smoking did not determine any increase of MN frequency. A total

  1. Biomonitoring of exposure to urban air pollutants: analysis of sister chromatid exchanges and DNA lesions in peripheral lymphocytes of traffic policemen.

    PubMed

    Carere, A; Andreoli, C; Galati, R; Leopardi, P; Marcon, F; Rosati, M V; Rossi, S; Tomei, F; Verdina, A; Zijno, A; Crebelli, R

    2002-07-25

    In order to elucidate the health effects of occupational exposure to traffic fumes, a few biomarkers of early genetic effect were investigated in Rome traffic policemen. One hundred and ninety healthy subjects engaged in traffic control (133 subjects) or in office work (57 subjects) participated the study. For all subjects, detailed information on smoking habits and other potential confounders were recorded by questionnaires. Average exposure of the study groups to benzene and other aromatic hydrocarbons was evaluated in a parallel exposure survey. All workers were genotyped for the following metabolic polymorphisms: CYP1A1 (m1, m2, and m4 variants), CYP2E1 (PstI and RsaI), NQO1 (Hinf1), GSTM1 and GSTT1 (null variants). In this paper, the results of the analysis of sister chromatid exchanges (SCE) in peripheral lymphocytes, and DNA damage by alkaline (pH 13) comet assay in mononuclear blood cells are reported. No statistically significant difference in the frequency of SCE or high frequency cells (HFC) was observed between traffic wardens and office workers (controls), despite the significantly higher exposure to benzene of the former (average group exposure 9.5 versus 3.8microg/m(3), 7h TWA). Conversely, both SCE per cell and HFC were highly significantly (P<0.001) increased in smokers compared to nonsmokers, showing a significant correlation (P<0.001) with the number of cigarettes per day. Multiple regression analyses of data, with metabolic polymorphisms, smoking habits, alcohol consumption, age, gender, and family history of cancer as independent variables, showed that smoking habits, and possibly the CYP2E1 variant genotypes, were the main factors explaining the variance of both SCE and HFC. Within smokers, an association of borderline significance between the CYP1A1 variant genotypes and increased SCE (P=0.050) and HFC (P=0.090) was found. This effect was mainly observed in light smokers (<15 cigarettes per day). The analysis of DNA damage by comet assay did

  2. Enhanced G2 chromatid radiosensitivity in dyskeratosis congenita fibroblasts.

    PubMed Central

    DeBauche, D M; Pai, G S; Stanley, W S

    1990-01-01

    Dyskeratosis congenita (DC) is an inherited disorder characterized by reticular pigmentation of the skin, dystrophic nails, mucosal leukoplakia, and a predisposition to cancer in early adult life. In the majority of cases, DC is an X-linked recessive trait. However, one or more autosomal form(s) of DC may exist. Although excessive spontaneous chromatid breakage has been reported in DC, it is not a consistent cytological marker for this disorder. We examined the frequency and specificity of X-irradiation-induced G2 chromatid breakage in fibroblasts from three unrelated DC patients (two males and one female). Metaphase cells from DC patients had significantly more chromatid breaks (16-18-fold and 17-26-fold at 50 and 100 rad X-irradiation, respectively) and chromatid gaps (10-12-fold and 6-7-fold at 50 and 100 rad, respectively) than those from two different controls. Analysis of banded chromosomes revealed a nonrandom distribution of chromatid aberrations in DC but not in controls, a distribution corresponding to some of the known breakpoints for cancer-specific rearrangements, constitutive fragile sites, and/or loci for cellular proto-oncogenes. The significance of this finding for cancer predisposition in DC patients is uncertain, but the increased susceptibility of X-irradiation-induced chromatid breakage may serve as a cellular marker of diagnostic value. PMID:2301400

  3. Cell killing and chromatid damage in primary human bronchial epithelial cells irradiated with accelerated 56Fe ions

    NASA Technical Reports Server (NTRS)

    Suzuki, M.; Piao, C.; Hall, E. J.; Hei, T. K.

    2001-01-01

    We examined cell killing and chromatid damage in primary human bronchial epithelial cells irradiated with high-energy 56Fe ions. Cells were irradiated with graded doses of 56Fe ions (1 GeV/nucleon) accelerated with the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The survival curves for cells plated 1 h after irradiation (immediate plating) showed little or no shoulder. However, the survival curves for cells plated 24 h after irradiation (delayed plating) had a small initial shoulder. The RBE for 56Fe ions compared to 137Cs gamma rays was 1.99 for immediate plating and 2.73 for delayed plating at the D10. The repair ratio (delayed plating/immediate plating) was 1.67 for 137Cs gamma rays and 1.22 for 56Fe ions. The dose-response curves for initially measured and residual chromatid fragments detected by the Calyculin A-mediated premature chromosome condensation technique showed a linear response. The results indicated that the induction frequency for initially measured fragments was the same for 137Cs gamma rays and 56Fe ions. On the other hand, approximately 85% of the fragments induced by 137Cs gamma rays had rejoined after 24 h of postirradiation incubation; the corresponding amount for 56Fe ions was 37%. Furthermore, the frequency of chromatid exchanges induced by gamma rays measured 24 h after irradiation was higher than that induced by 56Fe ions. No difference in the amount of chromatid damage induced by the two types of radiations was detected when assayed 1 h after irradiation. The results suggest that high-energy 56Fe ions induce a higher frequency of complex, unrepairable damage at both the cellular and chromosomal levels than 137Cs gamma rays in the target cells for radiation-induced lung cancers.

  4. In vitro induction of polyploidy and chromatid exchanges by culture medium extracts of natural rubbers compounded with 2-mercaptobenzothiazole as a positive control candidate for genotoxicity tests.

    PubMed

    Matsuoka, Atsuko; Isama, Kazuo; Tsuchiya, Toshie

    2005-11-01

    We tested extracts of custom-made natural rubber samples for cytotoxicity using V79 cells and for chromosome aberration (CA) induction using CHL cells in compliance with the Japanese guidelines for basic biological tests of medical materials and devices. The samples were formulated with a high level of 2-mercaptobenzothiazole (MBT) (A); a low level of MBT (B); or zinc dibutyldithiocarbamate (ZDBC) (C). In the CA test, MBT induced mainly polyploidy, including endoreduplication, and ZDBC induced structural CAs. In the cytotoxicity test, culture medium extracts of A, B, and C suppressed colony formation to 50% of the control value at 53.1%, 94.3%, and >100%, respectively. Culture medium extracts of sample A induced polyploidy and structural CAs in the absence of an exogenous metabolic activation system (S9 mix), but at lower concentrations in its presence, indicating the existence of other leachable promutagens. The extracts of sample B induced structural CAs at the highest concentration and only with S9 mix. Sample C was negative. The facts suggest that sample A may be a candidate for a positive control for genotoxicity tests. The high frequency of polyploidy induced by sample A was not predicted by MBT, suggesting the usefulness of the test for safety evaluation of medical devices. Numerical CAs induced by MBT and sample A are discussed. PMID:16088893

  5. A historical overview of bromo-substituted DNA and sister chromatid differentiation.

    PubMed

    Mezzanotte, Roberto; Nieddu, Mariella

    2014-01-01

    The thymidine analogue 5-bromo-2'-deoxyuridine (BrdU) has been widely used to make sister chromatid differentiation (SCD) evident in metaphase chromosomes of cells grown for two cycles in BrdU and, thus, containing varying amounts of the thymidine analogue. A direct consequence was the possibility of making sister chromatid exchange (SCE) evident without using autoradiographic procedures. The latter phenomenon was first discovered in 1953, and its frequency is considered a reliable marker of pathological cell situations, as well as an indicator of mutagenic compounds. Several experimental procedures were found which produced SCD, such as the use of fluorochromes like 33258 Hoechst or acridine orange, whose observation under fluorescence microscopy was directly recorded by photos or stained with Giemsa to make chromosome preparations permanent. Other treatments followed by Giemsa staining required the use of saline hot solutions, acid solutions, nuclease attack and specific monoclonal antibodies. Basically two molecular mechanisms were invoked to explain the different affinity of Giemsa stain for differential BrdU-substituted chromatid DNA. The first implied debromination of chromatid DNA, whose occurrence would be greater in chromatids containing an amount of BrdU greater than that present in sister chromatids. The second mechanism, although not denying the importance of DNA debromination, postulated that chromatin structural organization, in terms of DNA-protein and/or protein-protein DNA interaction, is responsible for SCD production.

  6. Kinetics of chromatid break repair in G2-human fibroblasts exposed to low- and high-LET radiations

    NASA Technical Reports Server (NTRS)

    Kawata, T.; Durante, M.; George, K.; Furusawa, Y.; Gotoh, E.; Takai, N.; Wu, H.; Cucinotta, F. A.

    2001-01-01

    The purpose of this study is to determine the kinetics of chromatid break rejoining following exposure to radiations of different quality. Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (290 MeV/u), silicon (490 MeV/u) and iron (200 MeV/u, 600 MeV/u). Chromosomes were prematurely condensed using calyculin A. Prematurely condensed chromosomes were collected after several post-irradiation incubation times, ranging from 5 to 600 minutes, and the number of chromatid breaks and exchanges in G2 cells were scored. The relative biological effectiveness (RBE) for initial chromatid breaks per unit dose showed LET dependency having a peak at 55 keV/micrometers silicon (2.4) or 80 keV/micrometers carbon particles (2.4) and then decreased with increasing LET. The kinetics of chromatid break rejoining following low- or high-LET irradiation consisted of two exponential components. Chromatid breaks decreased rapidly after exposure, and then continued to decrease at a slower rate. The rejoining kinetics was similar for exposure to each type of radiation, although the rate of unrejoined breaks was higher for high-LET radiation. Chromatid exchanges were also formed quickly.

  7. The influence of automobile exhausts on mutagenicity of soils: contamination with, fractionation, separation, and preliminary identification of mutagens in the Salmonella/reversion assay and effects of solvent fractions on the sister-chromatid exchanges in human lymphocyte cultures and in the in vivo mouse bone marrow micronucleus assay.

    PubMed

    Wesp, H F; Tang, X; Edenharder, R

    2000-12-20

    S9. The modified tester strains, either deficient in nitroreductase (TA 98NR) or overproducing nitroreductase (YG 1021, 1026) or O-acetyl-transferase (YG 1024, 1026), indicated a major contribution of nitroarenes to soil mutagenicity. With respect to mutagenic PAH, high pressure liquid chromatography (HPLC) revealed that >90% of dibenz[a,h]anthracene (4.18mg/kg soil), benzo[a]pyrene (1.96mg), benzofluoranthenes (0.14mg), and benz[a]anthracene (0. 18mg) were present in the acetone subfraction of cyclohexane solubles. Concentrations and mutagenic activities, however, did not correlate. Additional preparative and analytical HPLC of the solvent fractions of polar neutrals and polar aromatics, resulted in the tentative identification of 2-nitrofluorene. Analysis of the vertical profile of soil revealed an increase of mutagenicity per gram from the surface to a maximum at 5-15cm depth and a subsequent decrease with very little activity remaining deeper than 35cm. In human lymphocyte cultures, the fraction of polar aromatics, 0.01-0. 3microg/ml, induced 11.27+/-4.76-20.70+/-6.19 sister-chromatid exchanges (SCE) per cell in the absence of S9 (solvent control: 10. 16+/-4.83 SCE per cell) and 12.77+/-6.53-17.87+/-4.93 SCE per cell in the presence of S9 (solvent control: 8.37+/-3.92 SCE per cell). However, no activities could be detected in the fractions of polar neutrals and non-polar neutrals. Again, negative results were obtained in the in vivo mouse bone marrow micronucleus assay at 2000mg/kg p.o. with all fractions. PMID:11113694

  8. Influence of naringin on cadmium-induced genomic damage in human lymphocytes in vitro.

    PubMed

    Yilmaz, Dilek; Aydemir, Nilufer Cinkilic; Vatan, Ozgür; Tüzün, Ece; Bilaloglu, Rahmi

    2012-03-01

    Cadmium is an important toxic environmental heavy metal. Generally, occupational and environmental exposures to cadmium result from heavy metal mining, metallurgy and industrial use and the manufacturing of nickel-cadmium batteries, pigments and plastic stabilizers. Cadmium induces oxidative stress and alters the antioxidant system, resulting in oxidative DNA damage and lipid peroxidation. The effect of naringin, a grapefruit flavonone, on cadmium-induced genomic damage was studied by using an in vitro system to test for chromosomal aberrations and sister chromatid exchanges. Cadmium significantly increased the total chromosomal aberrations in human lymphocytes at concentrations of 20 and 40 μM, and although naringin alone did not induce any chromosomal aberrations, it decreased those induced by cadmium. The mitotic index was not affected by either cadmium or naringin. Cadmium also induced a significant number of sister chromatid exchanges, but naringin alone did not induce sister chromatid exchanges and was unable to decrease the frequency of sister chromatid exchanges induced by cadmium. Replicative index analysis revealed that naringin and cadmium did not significantly alter replicative index frequencies. In this study, we show that plant-based flavonoids, such as naringin, may reduce the genomic damage induced by cadmium and may protect the cellular environments from free radical damage by its possible antioxidative potential. PMID:21636685

  9. High-LET radiation-induced aberrations in prematurely condensed G2 chromosomes of human fibroblasts

    NASA Technical Reports Server (NTRS)

    Kawata, T.; Gotoh, E.; Durante, M.; Wu, H.; George, K.; Furusawa, Y.; Cucinotta, F. A.; Dicello, J. F. (Principal Investigator)

    2000-01-01

    PURPOSE: To determine the number of initial chromatid breaks induced by low- or high-LET irradiations, and to compare the kinetics of chromatid break rejoining for radiations of different quality. MATERIAL AND METHODS: Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (290MeV/u), silicon (490MeV/u) and iron (200 and 600 MeV/u). Chromosomes were prematurely condensed using calyculin A. Chromatid breaks and exchanges in G2 cells were scored. PCC were collected after several post-irradiation incubation times, ranging from 5 to 600 min. RESULTS: The kinetics of chromatid break rejoining following low- or high-LET irradiation consisted of two exponential components representing a rapid and a slow time constant. Chromatid breaks decreased rapidly during the first 10min after exposure, then continued to decrease at a slower rate. The rejoining kinetics were similar for exposure to each type of radiation. Chromatid exchanges were also formed quickly. Compared to low-LET radiation, isochromatid breaks were produced more frequently and the proportion of unrejoined breaks was higher for high-LET radiation. CONCLUSIONS: Compared with gamma-rays, isochromatid breaks were observed more frequently in high-LET irradiated samples, suggesting that an increase in isochromatid breaks is a signature of high-LET radiation exposure.

  10. Investigating the nature of chromatid breaks produced by restriction endonucleases.

    PubMed

    Harvey, A N; Savage, J R

    1997-01-01

    It is a basic assumption of the breakage-and-reunion theory that the majority of open chromatid breaks seen at metaphase are the residue of unrejoined primary breaks that have neither restituted nor rejoined illegitimately to form exchange aberrations. If Chinese hamster chromosomes with BrdU sister-chromatid differentiation are irradiated, and chromatid aberrations scored from G2 cells, some 15-20% of open breaks show a colour-jump at the point of discontinuity, indicating a two-lesion intrachange origin. Since we see complete forms of several intrachanges whose incomplete forms will also look like breaks, but devoid of a colour-jump, it appears that a substantial proportion of observed breaks are intrachange derived. Experiments to date show that the colour-jump proportion is constant, irrespective of radiation dose, radiation quality, BrdU concentration and hamster cell origin. It is the same for the very low "spontaneous' breaks found in control samples. Restriction endonucleases (RE) can be introduced into cells by various poration methods, and are highly efficient at producing all types of aberrations. This is taken as strong evidence that DNA dsb are significant lesions triggering aberrations. One might anticipate, therefore, that observed breaks will be predominantly unrejoined dsb, and the proportion of colour-jump break correspondingly low. We tested this supposition using three RE; Alu 1, a blunt-end cutter, Sau3A 1, a cohesive-end cutter, both with a short life-time in vivo, and Mbo 1, an isoschizomer of Sau3A 1, which has a long cutting life-time in vivo. Although there were differences in absolute yields of breaks, and of relative frequencies of aberration types recovered, the proportion of colour-jump breaks was as high as that in a parallel X-ray experiment, and fell well within the range encountered in all our previous experiments. It is difficult to reconcile this universal constancy of colour-jump breaks with the expectations of breakage

  11. Cell biology of cancer: BRCA1 and sister chromatid pairing reactions?

    PubMed

    Skibbens, Robert V

    2008-02-15

    A significant portion of familial breast/ovarian cancer patients harbors a mutation in Breast Cancer Associated gene 1 (BRCA1). Cells deficient for BRCA1 exhibit chromosome aberrations such as whole chromosome duplications, translocations, inter-sister gaps and gene mis-regulation. Here, new evidence is reviewed that defects in sister chromatid cohesion may contribute directly to cancer cell phenotypes-especially those of BRCA1 mutant cells. Linking cohesion to BRCA1-dependent tumorigenesis are reports that BRCA1-associated components (DNA helicase, RFC, PCNA and genome surveillance factors) are required for efficient sister chromatid cohesion. Other cohesion factors (WAPL, EFO2/ESCO2 and hSecurin) are tightly correlated with various cell-type specific carcinogenesis, in support of a generalized model for cohesion in cancer. Recent findings further reveal that a reciprocal relationship exists in that DNA damage induces new Ctf7/Eco1-dependent sister chromatid pairing reactions that, in turn, are required for efficient DNA repair. Future research into sister chromatid pairing mechanisms are likely to provide critical new insights into the underlying causes of cancer.

  12. G2 Chromatid Damage and Repair Kinetics in Normal Human Fibroblast Cells Exposed to Low-or High-LET Radiation

    NASA Technical Reports Server (NTRS)

    Kawata, T.; Ito, H.; Uno, T.; Saito, M.; Yamamoto, S.; Furusawa, Y.; Durante, M.; George, K.; Wu, H.; Cucinotta, F. A.

    2004-01-01

    Radiation-induced chromosome damage can be measured in interphase using the Premature Chromosome Condensation (PCC) technique. With the introduction of a new PCC technique using the potent phosphatase inhibitor calyculin-A, chromosomes can be condensed within five minutes, and it is now possible to examine the early damage induced by radiation. Using this method, it has been shown that high-LET radiation induces a higher frequency of chromatid breaks and a much higher frequency of isochromatid breaks than low-LET radiation. The kinetics of chromatid break rejoining consists of two exponential components representing a rapid and a slow time constant, which appears to be similar for low- and high- LET radiations. However, after high-LET radiation exposures, the rejoining process for isochromatid breaks influences the repair kinetics of chromatid-type breaks, and this plays an important role in the assessment of chromatid break rejoining in the G2 phase of the cell cycle.

  13. Commitment in Structurally Enabled and Induced Exchange Relations

    ERIC Educational Resources Information Center

    Lawler, Edward J.; Thye, Shane R.; Yoon, Jeongkoo

    2006-01-01

    Network structures both enable and constrain the development of social relations. This research investigates these features by comparing the development of commitments in structurally enabled and structurally induced exchange relations. We integrate ideas from the theory of relational cohesion and the choice process theory of commitment. In an…

  14. Sister chromatid decatenation: bridging the gaps in our knowledge

    PubMed Central

    Broderick, Ronan; Niedzwiedz, Wojciech

    2015-01-01

    Faithful chromosome segregation is critical in preventing genome loss or damage during cell division. Failure to properly disentangle catenated sister chromatids can lead to the formation of bulky or ultrafine anaphase bridges, and ultimately genome instability. In this review we present an overview of the current state of knowledge of how sister chromatid decatenation is carried out, with particular focus on the role of TOP2A and TOPBP1 in this process. PMID:26266709

  15. Sister chromatid segregation in meiosis II: deprotection through phosphorylation.

    PubMed

    Wassmann, Katja

    2013-05-01

    Meiotic divisions (meiosis I and II) are specialized cell divisions to generate haploid gametes. The first meiotic division with the separation of chromosomes is named reductional division. The second division, which takes place immediately after meiosis I without intervening S-phase, is equational, with the separation of sister chromatids, similar to mitosis. This meiotic segregation pattern requires the two-step removal of the cohesin complex holding sister chromatids together: cohesin is removed from chromosome arms that have been subjected to homologous recombination in meiosis I and from the centromere region in meiosis II. Cohesin in the centromere region is protected from removal in meiosis I, but this protection has to be removed--deprotected--for sister chromatid segregation in meiosis II. Whereas the mechanisms of cohesin protection are quite well understood, the mechanisms of deprotection have been largely unknown until recently. In this review I summarize our current knowledge on cohesin deprotection.

  16. A Long Noncoding RNA Regulates Sister Chromatid Cohesion.

    PubMed

    Marchese, Francesco P; Grossi, Elena; Marín-Béjar, Oskar; Bharti, Sanjay Kumar; Raimondi, Ivan; González, Jovanna; Martínez-Herrera, Dannys Jorge; Athie, Alejandro; Amadoz, Alicia; Brosh, Robert M; Huarte, Maite

    2016-08-01

    Long noncoding RNAs (lncRNAs) are involved in diverse cellular processes through multiple mechanisms. Here, we describe a previously uncharacterized human lncRNA, CONCR (cohesion regulator noncoding RNA), that is transcriptionally activated by MYC and is upregulated in multiple cancer types. The expression of CONCR is cell cycle regulated, and it is required for cell-cycle progression and DNA replication. Moreover, cells depleted of CONCR show severe defects in sister chromatid cohesion, suggesting an essential role for CONCR in cohesion establishment during cell division. CONCR interacts with and regulates the activity of DDX11, a DNA-dependent ATPase and helicase involved in DNA replication and sister chromatid cohesion. These findings unveil a direct role for an lncRNA in the establishment of sister chromatid cohesion by modulating DDX11 enzymatic activity. PMID:27477908

  17. Anaphase chromatid motion: involvement of type II DNA topoisomerases.

    PubMed Central

    Duplantier, B; Jannink, G; Sikorav, J L

    1995-01-01

    Sister chromatids are topologically intertwined at the onset of anaphase: their segregation during anaphase is known to require strand-passing activity by type II DNA topoisomerase. We propose that the removal of the intertwinings involves at the same time the traction of the mitotic spindle and the activity of topoisomerases. This implies that the velocity of the chromatids is compatible with the kinetic constraints imposed by the enzymatic reaction. We show that the greatest observed velocities (about 0.1 microns s-1) are close to the theoretical upper bound compatible with both the diffusion rate (calculated here within a probabilistic model) and the measured reaction rate of the enzyme. PMID:8534830

  18. Thermal induced flow oscillations in heat exchangers for supercritical fluids

    NASA Technical Reports Server (NTRS)

    Friedly, J. C.; Manganaro, J. L.; Krueger, P. G.

    1972-01-01

    Analytical model has been developed to predict possible unstable behavior in supercritical heat exchangers. From complete model, greatly simplified stability criterion is derived. As result of this criterion, stability of heat exchanger system can be predicted in advance.

  19. Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers

    SciTech Connect

    Uvan Catton; Vijay K. Dhir; Deepanjan Mitra; Omar Alquaddoomi; Pierangelo Adinolfi

    2004-04-06

    Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers.

  20. EXCHANGE

    SciTech Connect

    Boltz, J.C.

    1992-09-01

    EXCHANGE is published monthly by the Idaho National Engineering Laboratory (INEL), a multidisciplinary facility operated for the US Department of Energy (DOE). The purpose of EXCHANGE is to inform computer users about about recent changes and innovations in both the mainframe and personal computer environments and how these changes can affect work being performed at DOE facilities.

  1. Securin and not CDK1/cyclin B1 regulates sister chromatid disjunction during meiosis II in mouse eggs.

    PubMed

    Nabti, Ibtissem; Reis, Alexandra; Levasseur, Mark; Stemmann, Olaf; Jones, Keith T

    2008-09-15

    Mammalian eggs remain arrested at metaphase of the second meiotic division (metII) for an indeterminate time before fertilization. During this period, which can last several hours, the continued attachment of sister chromatids is thought to be achieved by inhibition of the protease separase. Separase is known to be inhibited by binding either securin or Maturation (M-Phase)-Promoting Factor, a heterodimer of CDK1/cyclin B1. However, the relative contribution of securin and CDK/cyclin B1 to sister chromatid attachment during metII arrest has not been assessed. Although there are conditions in which either CDK1/cyclinB1 activity or securin can prevent sister chromatid disjunction, principally by overexpression of non-degradable cyclin B1 or securin, we find here that separase activity is primarily regulated by securin and not CDK1/cyclin B1. Thus the CDK1 inhibitor roscovitine and an antibody we designed to block the interaction of CDK1/cyclin B1 with separase, both failed to induce sister disjunction. In contrast, securin morpholino knockdown specifically induced loss of sister attachment, that could be restored by securin cRNA rescue. During metII arrest separase appears primarily regulated by securin binding, not CDK1/cyclin B1. PMID:18639540

  2. Compaction and segregation of sister chromatids via active loop extrusion

    PubMed Central

    Goloborodko, Anton; Imakaev, Maxim V; Marko, John F; Mirny, Leonid

    2016-01-01

    The mechanism by which chromatids and chromosomes are segregated during mitosis and meiosis is a major puzzle of biology and biophysics. Using polymer simulations of chromosome dynamics, we show that a single mechanism of loop extrusion by condensins can robustly compact, segregate and disentangle chromosomes, arriving at individualized chromatids with morphology observed in vivo. Our model resolves the paradox of topological simplification concomitant with chromosome 'condensation', and explains how enzymes a few nanometers in size are able to control chromosome geometry and topology at micron length scales. We suggest that loop extrusion is a universal mechanism of genome folding that mediates functional interactions during interphase and compacts chromosomes during mitosis. DOI: http://dx.doi.org/10.7554/eLife.14864.001 PMID:27192037

  3. An Smc3 Acetylation Cycle Is Essential for Establishment of Sister Chromatid Cohesion

    PubMed Central

    Beckouët, Frederic; Hu, Bin; Roig, Maurici B.; Sutani, Takashi; Komata, Makiko; Uluocak, Pelin; Katis, Vittorio L.; Shirahige, Katsuhiko; Nasmyth, Kim

    2015-01-01

    SUMMARY Sister chromatid cohesion is thought to involve entrapment of sister DNAs by a tripartite ring composed of the cohesin subunits Smc1, Smc3, and Scc1. Establishment of cohesion during S phase depends on acetylation of Smc3’s nucleotide-binding domain (NBD) by the Eco1 acetyl transferase. It is destroyed at the onset of anaphase due to Scc1 cleavage by separase. In yeast, Smc3 acetylation is reversed at anaphase by the Hos1 deacetylase as a consequence of Scc1 cleavage. Smc3 molecules that remain acetylated after mitosis due to Hos1 inactivation cannot generate cohesion during the subsequent S phase, implying that cohesion establishment depends on de novo acetylation during DNA replication. By inducing Smc3 deacetylation in postreplicative cells due to Hos1 overexpression, we provide evidence that Smc3 acetylation contributes to the maintenance of sister chromatid cohesion. A cycle of Smc3 NBD acetylation is therefore an essential aspect of the chromosome cycle in eukaryotic cells. PMID:20832721

  4. RSC facilitates Rad59-dependent homologous recombination between sister chromatids by promoting cohesin loading at DNA double-strand breaks.

    PubMed

    Oum, Ji-Hyun; Seong, Changhyun; Kwon, Youngho; Ji, Jae-Hoon; Sid, Amy; Ramakrishnan, Sreejith; Ira, Grzegorz; Malkova, Anna; Sung, Patrick; Lee, Sang Eun; Shim, Eun Yong

    2011-10-01

    Homologous recombination repairs DNA double-strand breaks by searching for, invading, and copying information from a homologous template, typically the homologous chromosome or sister chromatid. Tight wrapping of DNA around histone octamers, however, impedes access of repair proteins to DNA damage. To facilitate DNA repair, modifications of histones and energy-dependent remodeling of chromatin are required, but the precise mechanisms by which chromatin modification and remodeling enzymes contribute to homologous DNA repair are unknown. Here we have systematically assessed the role of budding yeast RSC (remodel structure of chromatin), an abundant, ATP-dependent chromatin-remodeling complex, in the cellular response to spontaneous and induced DNA damage. RSC physically interacts with the recombination protein Rad59 and functions in homologous recombination. Multiple recombination assays revealed that RSC is uniquely required for recombination between sister chromatids by virtue of its ability to recruit cohesin at DNA breaks and thereby promoting sister chromatid cohesion. This study provides molecular insights into how chromatin remodeling contributes to DNA repair and maintenance of chromatin fidelity in the face of DNA damage.

  5. Mek1 Kinase Is Regulated To Suppress Double-Strand Break Repair between Sister Chromatids during Budding Yeast Meiosis▿

    PubMed Central

    Niu, Hengyao; Li, Xue; Job, Emily; Park, Caroline; Moazed, Danesh; Gygi, Steven P.; Hollingsworth, Nancy M.

    2007-01-01

    Mek1 is a meiosis-specific kinase in budding yeast which promotes recombination between homologous chromosomes by suppressing double-strand break (DSB) repair between sister chromatids. Previous work has shown that in the absence of the meiosis-specific recombinase gene, DMC1, cells arrest in prophase due to unrepaired DSBs and that Mek1 kinase activity is required in this situation to prevent repair of the breaks using sister chromatids. This work demonstrates that Mek1 is activated in response to DSBs by autophosphorylation of two conserved threonines, T327 and T331, in the Mek1 activation loop. Using a version of Mek1 that can be conditionally dimerized during meiosis, Mek1 function was shown to be promoted by dimerization, perhaps as a way of enabling autophosphorylation of the activation loop in trans. A putative HOP1-dependent dimerization domain within the C terminus of Mek1 has been identified. Dimerization alone, however, is insufficient for activation, as DSBs and Mek1 recruitment to the meiosis-specific chromosomal core protein Red1 are also necessary. Phosphorylation of S320 in the activation loop inhibits sister chromatid repair specifically in dmc1Δ-arrested cells. Ectopic dimerization of Mek1 bypasses the requirement for S320 phosphorylation, suggesting this phosphorylation is necessary for maintenance of Mek1 dimers during checkpoint-induced arrest. PMID:17526735

  6. Reversible brain inactivation induces discontinuous gas exchange in cockroaches.

    PubMed

    Matthews, Philip G D; White, Craig R

    2013-06-01

    Many insects at rest breathe discontinuously, alternating between brief bouts of gas exchange and extended periods of breath-holding. The association between discontinuous gas exchange cycles (DGCs) and inactivity has long been recognised, leading to speculation that DGCs lie at one end of a continuum of gas exchange patterns, from continuous to discontinuous, linked to metabolic rate (MR). However, the neural hypothesis posits that it is the downregulation of brain activity and a change in the neural control of gas exchange, rather than low MR per se, which is responsible for the emergence of DGCs during inactivity. To test this, Nauphoeta cinerea cockroaches had their brains inactivated by applying a Peltier-chilled cold probe to the head. Once brain temperature fell to 8°C, cockroaches switched from a continuous to a discontinuous breathing pattern. Re-warming the brain abolished the DGC and re-established a continuous breathing pattern. Chilling the brain did not significantly reduce the cockroaches' MR and there was no association between the gas exchange pattern displayed by the insect and its MR. This demonstrates that DGCs can arise due to a decrease in brain activity and a change in the underlying regulation of gas exchange, and are not necessarily a simple consequence of low respiratory demand.

  7. Investigating the Interplay between Sister Chromatid Cohesion and Homolog Pairing in Drosophila Nuclei.

    PubMed

    Senaratne, T Niroshini; Joyce, Eric F; Nguyen, Son C; Wu, C-Ting

    2016-08-01

    Following DNA replication, sister chromatids must stay connected for the remainder of the cell cycle in order to ensure accurate segregation in the subsequent cell division. This important function involves an evolutionarily conserved protein complex known as cohesin; any loss of cohesin causes premature sister chromatid separation in mitosis. Here, we examined the role of cohesin in sister chromatid cohesion prior to mitosis, using fluorescence in situ hybridization (FISH) to assay the alignment of sister chromatids in interphase Drosophila cells. Surprisingly, we found that sister chromatid cohesion can be maintained in G2 with little to no cohesin. This capacity to maintain cohesion is widespread in Drosophila, unlike in other systems where a reduced dependence on cohesin for sister chromatid segregation has been observed only at specific chromosomal regions, such as the rDNA locus in budding yeast. Additionally, we show that condensin II antagonizes the alignment of sister chromatids in interphase, supporting a model wherein cohesin and condensin II oppose each other's functions in the alignment of sister chromatids. Finally, because the maternal and paternal homologs are paired in the somatic cells of Drosophila, and because condensin II has been shown to antagonize this pairing, we consider the possibility that condensin II-regulated mechanisms for aligning homologous chromosomes may also contribute to sister chromatid cohesion. PMID:27541002

  8. Investigating the Interplay between Sister Chromatid Cohesion and Homolog Pairing in Drosophila Nuclei

    PubMed Central

    Senaratne, T. Niroshini; Joyce, Eric F.; Wu, C.-ting

    2016-01-01

    Following DNA replication, sister chromatids must stay connected for the remainder of the cell cycle in order to ensure accurate segregation in the subsequent cell division. This important function involves an evolutionarily conserved protein complex known as cohesin; any loss of cohesin causes premature sister chromatid separation in mitosis. Here, we examined the role of cohesin in sister chromatid cohesion prior to mitosis, using fluorescence in situ hybridization (FISH) to assay the alignment of sister chromatids in interphase Drosophila cells. Surprisingly, we found that sister chromatid cohesion can be maintained in G2 with little to no cohesin. This capacity to maintain cohesion is widespread in Drosophila, unlike in other systems where a reduced dependence on cohesin for sister chromatid segregation has been observed only at specific chromosomal regions, such as the rDNA locus in budding yeast. Additionally, we show that condensin II antagonizes the alignment of sister chromatids in interphase, supporting a model wherein cohesin and condensin II oppose each other’s functions in the alignment of sister chromatids. Finally, because the maternal and paternal homologs are paired in the somatic cells of Drosophila, and because condensin II has been shown to antagonize this pairing, we consider the possibility that condensin II-regulated mechanisms for aligning homologous chromosomes may also contribute to sister chromatid cohesion. PMID:27541002

  9. Mechanics of Sister Chromatids studied with a Polymer Model English</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yang; Isbaner, Sebastian; Heermann, Dieter</p> <p>2013-10-01</p> <p>Sister <span class="hlt">chromatid</span> cohesion denotes the phenomenon that sister <span class="hlt">chromatids</span> are initially attached to each other in mitosis to guarantee the error-free distribution into the daughter cells. Cohesion is mediated by binding proteins and only resolved after mitotic chromosome condensation is completed. However, the amount of attachement points required to maintain sister <span class="hlt">chromatid</span> cohesion while still allowing proper chromosome condensation is not known yet. Additionally the impact of cohesion on the mechanical properties of chromosomes also poses an interesting problem. In this work we study the conformational and mechanical properties of sister <span class="hlt">chromatids</span> by means of computer simulations. We model both protein-mediated cohesion between sister <span class="hlt">chromatids</span> and chromosome condensation with a dynamic binding mechanisms. We show in a phase diagram that only specific link concentrations lead to connected and fully condensed <span class="hlt">chromatids</span> that do not intermingle with each other nor separate due to entropic forces. Furthermore we show that dynamic bonding between <span class="hlt">chromatids</span> decrease the Young's modulus compared to non-bonded <span class="hlt">chromatids</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2552L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2552L"><span id="translatedtitle">Analysis of <span class="hlt">induced</span> temperature anomalies along borehole heat <span class="hlt">exchangers</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lindner, Michael; Schelenz, Sophie; Stollberg, Reiner; Gossel, Wolfgang; Dietrich, Peter; Vienken, Thomas</p> <p>2015-04-01</p> <p>Over the last years, the thermal use of the shallow subsurface for heat generation, cooling, and thermal energy storage has increased. However, the injection or extraction of heat potentially drives changes in the subsurface temperature regime; especially in urban areas. The presented case study investigates the intensive use of borehole heat <span class="hlt">exchangers</span> (BHE) and their potential thermal impacts on subsurface temperatures, as well as thermal interactions between individual BHE's for a residential neighborhood in Cologne, Germany. Based on on-site subsurface parameterization, a 3D subsurface model was designed, using the finite element software FEFLOW (DHI WASY). The model contains five BHE, extracting 8.2 kW, with a maximum BHE depth of 38 m, whereby the thickness of the unsaturated zone is 22 m. The simulated time span is 10 years. This study focusses on two questions: How will different BHE arrangements vary in terms of temperature plume formation and potential system interaction and what is the influence of seasonal subsurface heat storage on soil and ground water temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006HyPr...20.4287K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006HyPr...20.4287K"><span id="translatedtitle">Hyporheic <span class="hlt">exchange</span> flows <span class="hlt">induced</span> by constructed riffles and steps in lowland streams in southern Ontario, Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasahara, Tamao; Hill, Alan R.</p> <p>2006-12-01</p> <p>Stream-subsurface water interaction <span class="hlt">induced</span> by natural riffles and constructed riffles/steps was examined in lowland streams in southern Ontario, Canada. The penetration of stream water into the subsurface was analysed using hydrometric data, and the zone of > 10% stream water was calculated from a chemical mixing equation using tracer injection of bromide and background chloride concentrations. The constructed riffles studied <span class="hlt">induced</span> more extensive hyporheic <span class="hlt">exchange</span> than the natural riffles because of their steeper longitudinal hydraulic head gradients and coarser streambed sediments. The depth of > 10% stream water zone in a small and a large constructed riffle extended to > 0.2 m and > 1.4 m depths respectively. Flux and residence time distribution of hyporheic <span class="hlt">exchange</span> were simulated in constructed riffles using MODFLOW, a finite-difference groundwater flow model. Hyporheic flux and residence time distribution varied along the riffles, and the <span class="hlt">exchange</span> occurring upstream from the riffle crest was small in flux and had a long residence time. In contrast, hyporheic <span class="hlt">exchange</span> occurring downstream from the riffle crest had a relatively short residence time and accounted for 83% and 70% of total hyporheic <span class="hlt">exchange</span> flow in a small and large riffle respectively. Although stream restoration projects have not considered the hyporheic zone, our data indicate that constructed riffles and steps can promote vertical hydrologic <span class="hlt">exchange</span> and increase the groundwater-surface water linkage in degraded lowland streams. Copyright</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EL....11437001N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EL....11437001N"><span id="translatedtitle"><span class="hlt">Exchange</span> bias-like effect in TbFeAl <span class="hlt">induced</span> by atomic disorder</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nair, Harikrishnan S.; Strydom, André M.</p> <p>2016-05-01</p> <p>The <span class="hlt">exchange</span> bias-like effect observed in the intermetallic compound TbFeAl, which displays a magnetic phase transition at T^hc ≈ 198 \\text{K} and a second one at T^lc ≈ 154 \\text{K} , is reported. Jump-like features are observed in the isothermal magnetization, M (H) , at 2 K which disappear above 8 K. The field-cooled magnetization isotherms below 10 K show loop shifts that are reminiscent of <span class="hlt">exchange</span> bias, also supported by the training effect. A significant coercive field, Hc ≈ 1.5 \\text{T} at 2 K, is observed in TbFeAl which, after an initial increase, shows a subsequent decrease with temperature. The <span class="hlt">exchange</span> bias field, H eb , shows a slight increase and a subsequent leveling off with temperature. It is argued that the inherent crystallographic disorder among Fe and Al and the high magnetocrystalline anisotropy related to Tb3+ lead to the <span class="hlt">exchange</span> bias effect. TbFeAl has been recently reported to show the magnetocaloric effect and the present discovery of <span class="hlt">exchange</span> bias makes this compound a multifunctional one. The result obtained on TbFeAl generalizes the observation of <span class="hlt">exchange</span> bias in crystallographically disordered materials and gives impetus for the search for materials with <span class="hlt">exchange</span> bias <span class="hlt">induced</span> by atomic disorder.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55g0304O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55g0304O"><span id="translatedtitle"><span class="hlt">Exchange</span> bias controlled by electric current: Interplay of Joule heating and the <span class="hlt">induced</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oda, Kent; Moriyama, Takahiro; Kawaguchi, Masashi; Kamiya, Michinari; Tanaka, Kensho; Kim, Kab-Jin; Ono, Teruo</p> <p>2016-07-01</p> <p><span class="hlt">Exchange</span> bias is a unidirectional magnetic anisotropy developed in a bilayer of ferromagnetic and antiferromagnetic layers. Its technical importance as a “fix layer” is seen in various spintronic devices. The <span class="hlt">exchange</span> bias can also be a probe to investigate the antiferromagnetic layer as it partly reflects the magnetic state of the antiferromagnet. In this work, we investigated the modulation of the <span class="hlt">exchange</span> bias by a flow of electric current in Pt/Fe50Mn50/FeNi and Cu/Fe50Mn50/FeNi. We show that the <span class="hlt">exchange</span> bias can be modulated just by applying the current due to interplay among the Joule heating, Ampere field, and current-<span class="hlt">induced</span> effective field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/822365','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/822365"><span id="translatedtitle">Development of Design Criteria for Fluid <span class="hlt">Induced</span> Structural Vibration in Steam Generators and Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo</p> <p>2004-03-26</p> <p>OAK-B135 Flow-<span class="hlt">induced</span> vibration in heat <span class="hlt">exchangers</span> has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat <span class="hlt">exchangers</span> due to apparent flow-<span class="hlt">induced</span> vibration have been reported through the USNRC incident reporting system. Almost all heat <span class="hlt">exchangers</span> have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-<span class="hlt">induced</span> vibration is constantly updated with new findings and improved design criteria for heat <span class="hlt">exchangers</span>. In the nuclear industry, steam generators are often affected by this problem. However, flow-<span class="hlt">induced</span> vibration is not limited to nuclear power plants, but to any type of heat <span class="hlt">exchanger</span> used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat <span class="hlt">exchangers</span> experience flow-<span class="hlt">induced</span> vibration due to the high velocity flow over the tube banks. Flow-<span class="hlt">induced</span> vibration in these heat <span class="hlt">exchangers</span> leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat <span class="hlt">exchangers</span>. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18202362','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18202362"><span id="translatedtitle">Role of the Saccharomyces cerevisiae Rad51 paralogs in sister <span class="hlt">chromatid</span> recombination.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mozlin, Amy M; Fung, Cindy W; Symington, Lorraine S</p> <p>2008-01-01</p> <p>Rad51 requires a number of other proteins, including the Rad51 paralogs, for efficient recombination in vivo. Current evidence suggests that the yeast Rad51 paralogs, Rad55 and Rad57, are important in formation or stabilization of the Rad51 nucleoprotein filament. To gain further insights into the function of the Rad51 paralogs, reporters were designed to measure spontaneous or double-strand break (DSB)-<span class="hlt">induced</span> sister or nonsister recombination. Spontaneous sister <span class="hlt">chromatid</span> recombination (SCR) was reduced 6000-fold in the rad57 mutant, significantly more than in the rad51 mutant. Although the DSB-<span class="hlt">induced</span> recombination defect of rad57 was suppressed by overexpression of Rad51, elevated temperature, or expression of both mating-type alleles, the rad57 defect in spontaneous SCR was not strongly suppressed by these same factors. In addition, the UV sensitivity of the rad57 mutant was not strongly suppressed by MAT heterozygosity, even though Rad51 foci were restored under these conditions. This lack of suppression suggests that Rad55 and Rad57 have different roles in the recombinational repair of stalled replication forks compared with DSB repair. Furthermore, these data suggest that most spontaneous SCR initiates from single-stranded gaps formed at stalled replication forks rather than DSBs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145417','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145417"><span id="translatedtitle">Securin degradation is mediated by fzy and fzr, and is required for complete <span class="hlt">chromatid</span> separation but not for cytokinesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zur, Amit; Brandeis, Michael</p> <p>2001-01-01</p> <p>We have studied the ubiquitination and degradation patterns of the human securin/PTTG protein. We show that, in contrast to budding yeast pds1, securin degradation is catalyzed by both fzy (fizzy/cdc20) and fzr (fizzy-related/cdh1/hct1). Both fzy and fzr also <span class="hlt">induce</span> the APC/C to ubiquitinate securin in vitro. Securin degradation is mediated by an RXXL destruction box and a KEN box, and is inhibited only when both sequences are mutated. Interestingly, the non-degradable securin mutant is also partially ubiquitinated by fzy and fzr in vitro. Expressing the non-degradable securin mutant in cells frequently resulted in incomplete <span class="hlt">chromatid</span> separation and gave rise to daughter cells connected by a thin chromatin fiber, presumably of chromosomes that failed to split completely. Strikingly, the mutant securin did not prevent the majority of sister <span class="hlt">chromatids</span> from separating completely, nor did it prevent mitotic cyclin degradation and cytokinesis. This phenotype, reminiscent of the fission yeast cut (cells untimely torn) phenotype, is reported here for the first time in mammals. PMID:11179223</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SSCom.230...11C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SSCom.230...11C"><span id="translatedtitle">Tiny Ni-NiO nanocrystals with <span class="hlt">exchange</span> bias <span class="hlt">induced</span> room temperature ferromagnetism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaghouri, Hanan Al; Tuna, F.; Santhosh, P. N.; Thomas, P. John</p> <p>2016-03-01</p> <p>Ni nanocrystals coated with a thin layer of NiO with a diameter of 5.0 nm show <span class="hlt">exchange</span> bias <span class="hlt">induced</span> ferromagnetism at room temperature. These particulates are freely dispersible in water and were obtained by annealing Ni nanoparticles coated with a thin amorphous layer of NiO. Particulates with diameters between 5.0 and 16.8 nm are studied. Detailed magnetic measurements reveal signs consistent with strong <span class="hlt">exchange</span> bias including elevated blocking temperatures and tangible loop shifts. The structure of the particulates are characterized by high resolution transmission electron microscopy, energy dispersive x-ray analysis and x-ray diffraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25643137','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25643137"><span id="translatedtitle">Interfacial <span class="hlt">exchange</span> coupling <span class="hlt">induced</span> anomalous anisotropic magnetoresistance in epitaxial γ'-Fe₄N/CoN bilayers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Zirun; Mi, Wenbo; Wang, Xiaocha; Zhang, Xixiang</p> <p>2015-02-18</p> <p>Anisotropic magnetoresistance (AMR) of the facing-target reactively sputtered epitaxial γ'-Fe4N/CoN bilayers is investigated. The phase shift and rectangular-like AMR appears at low temperatures, which can be ascribed to the interfacial <span class="hlt">exchange</span> coupling. The phase shift comes from the <span class="hlt">exchange</span> bias (EB) that makes the magnetization lag behind a small field. When the γ'-Fe4N thickness increases, the rectangular-like AMR appears. The rectangular-like AMR should be from the combined contributions including the EB-<span class="hlt">induced</span> unidirectional anisotropy, intrinsic AMR of γ'-Fe4N layer and interfacial spin scattering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4933981','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4933981"><span id="translatedtitle">Plasma <span class="hlt">exchange</span> in the treatment of thyroid storm secondary to type II amiodarone-<span class="hlt">induced</span> thyrotoxicosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zainudin, Sueziani Binte; Kaushik, Manish; Khor, Li Yan; Chng, Chiaw Ling</p> <p>2016-01-01</p> <p>Summary Type II amiodarone-<span class="hlt">induced</span> thyrotoxicosis (AIT) is an uncommon cause of thyroid storm. Due to the rarity of the condition, little is known about the role of plasma <span class="hlt">exchange</span> in the treatment of severe AIT. A 56-year-old male presented with thyroid storm 2months following cessation of amiodarone. Despite conventional treatment, his condition deteriorated. He underwent two cycles of plasma <span class="hlt">exchange</span>, which successfully controlled the severe hyperthyroidism. The thyroid hormone levels continued to fall up to 10h following plasma <span class="hlt">exchange</span>. He subsequently underwent emergency total thyroidectomy and the histology of thyroid gland confirmed type II AIT. Management of thyroid storm secondary to type II AIT can be challenging as patients may not respond to conventional treatments, and thyroid storm may be more harmful in AIT patients owing to the underlying cardiac disease. If used appropriately, plasma <span class="hlt">exchange</span> can effectively reduce circulating hormones, to allow stabilisation of patients in preparation for emergency thyroidectomy. Learning points Type II AIT is an uncommon cause of thyroid storm and may not respond well to conventional thyroid storm treatment. Prompt diagnosis and therapy are important, as patients may deteriorate rapidly. Plasma <span class="hlt">exchange</span> can be used as an effective bridging therapy to emergency thyroidectomy. This case shows that in type II AIT, each cycle of plasma <span class="hlt">exchange</span> can potentially lower free triiodothyronine levels for 10h. Important factors to consider when planning plasma <span class="hlt">exchange</span> as a treatment for thyroid storm include timing of each session, type of <span class="hlt">exchange</span> fluid to be used and timing of surgery. PMID:27398220</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/153685','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/153685"><span id="translatedtitle">Novel ion-<span class="hlt">exchange</span> membranes for electrodialysis prepared by radiation-<span class="hlt">induced</span> graft polymerization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsuneda, Satoshi; Saito, Kyoichi; Misuhara, Hisashi; Sugo, Takanobu</p> <p>1995-11-01</p> <p>Ion-<span class="hlt">exchange</span> membranes have been used to concentrate seawater to produce salt as well as to desalinate brackish water to render it potable. Also, the interest in applications of ion-<span class="hlt">exchange</span> membranes as separators for electrodialytic desalination of bioproducts and separators in hydrogen-oxygen fuel cells has been growing. Novel ion-<span class="hlt">exchange</span> membranes containing sulfonic acid (SO{sub 3}H) and trimethyl ammonium [N(CH{sub 3}){sub 3}] groups were prepared by a simple method of radiation-<span class="hlt">induced</span> cografting of sodium styrene sulfonate (SSS) with acrylic acid (AAc) and vinyl benzyl trimethyl ammonium chloride (VBTAC) with 2-hydroxyethyl methacrylate (HEMA), onto a polyethylene film with a thickness of 50 {micro}m. The high density graft chain was introduced throughout the polyethylene film. The maximum cation- and anion-<span class="hlt">exchange</span> capacities of the resultant membranes were 2.5 and 1.3 mol/kg, receptively. These membranes exhibited an electrical resistance one order lower than commercially available ion-<span class="hlt">exchange</span> membranes; for example, 12 h cografting provided cation- and anion-<span class="hlt">exchange</span> membranes whose electrical resistances in a 0.5 M NaCl solution were 0.25 and 0.85 {Omega} cm{sup 2}, respectively. From the evaluation of electrodialytic desalination in a batch mode, using a pair of the graft-type ion-<span class="hlt">exchange</span> membranes, the time required to achieve 99.5% desalination of the initial 0.5 M NaCl solutions was reduced to 85% comparing with that of the commercial ion-<span class="hlt">exchange</span> membranes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22162960','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22162960"><span id="translatedtitle">Boron- and phosphorus-doped polycrystalline silicon thin films prepared by silver-<span class="hlt">induced</span> layer <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Antesberger, T.; Wassner, T. A.; Jaeger, C.; Algasinger, M.; Kashani, M.; Scholz, M.; Matich, S.; Stutzmann, M.</p> <p>2013-05-27</p> <p>Intentional boron and phosphorus doping of polycrystalline silicon thin films on glass prepared by the silver-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> is presented. A silver/(titanium) oxide/amorphous silicon stack is annealed at temperatures below the eutectic temperature of the Ag/Si system, leading to a complete layer <span class="hlt">exchange</span> and simultaneous crystallization of the amorphous silicon. Intentional doping of the amorphous silicon prior to the <span class="hlt">exchange</span> process results in boron- or phosphorus-doped polycrystalline silicon. Hall effect measurements show carrier concentrations between 2 Multiplication-Sign 10{sup 17} cm{sup -3} and 3 Multiplication-Sign 10{sup 20} cm{sup -3} for phosphorus and 4 Multiplication-Sign 10{sup 18} cm{sup -3} to 3 Multiplication-Sign 10{sup 19} cm{sup -3} for boron-doped layers, with carrier mobilities up to 90 cm{sup 2}/V s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JMagR.202..102L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JMagR.202..102L"><span id="translatedtitle">Protein-<span class="hlt">induced</span> water 1H MR frequency shifts: Contributions from magnetic susceptibility and <span class="hlt">exchange</span> effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, Jie; He, Xiang; d'Avignon, D. Andre'; Ackerman, Joseph J. H.; Yablonskiy, Dmitriy A.</p> <p>2010-01-01</p> <p>Defining the biophysics underlying the remarkable MRI phase contrast reported in high field MRI studies of human brain would lead to more quantitative image analysis and more informed pulse sequence development. Toward this end, the dependence of water 1H resonance frequency on protein concentration was investigated using bovine serum albumin (BSA) as a model system. Two distinct mechanisms were found to underlie a water 1H resonance frequency shift: (i) a protein-concentration-<span class="hlt">induced</span> change in bulk magnetic susceptibility, causing a shift to lower frequency, and (ii) <span class="hlt">exchange</span> of water between chemical-shift distinct environments, i.e., free (bulk water) and protein-associated ("bound") water, including freely <span class="hlt">exchangeable</span> 1H sites on proteins, causing a shift to higher frequency. At 37 °C the amplitude of the <span class="hlt">exchange</span> effect is roughly half that of the susceptibility effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567865','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567865"><span id="translatedtitle">Shugoshin1 May Play Important Roles in Separation of Homologous Chromosomes and Sister <span class="hlt">Chromatids</span> during Mouse Oocyte Meiosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yin, Shen; Ai, Jun-Shu; Shi, Li-Hong; Wei, Liang; Yuan, Ju; Ouyang, Ying-Chun; Hou, Yi; Chen, Da-Yuan; Schatten, Heide; Sun, Qing-Yuan</p> <p>2008-01-01</p> <p>Background Homologous chromosomes separate in meiosis I and sister <span class="hlt">chromatids</span> separate in meiosis II, generating haploid gametes. To address the question why sister <span class="hlt">chromatids</span> do not separate in meiosis I, we explored the roles of Shogoshin1 (Sgo1) in chromosome separation during oocyte meiosis. Methodology/Principal Findings Sgo1 function was evaluated by exogenous overexpression to enhance its roles and RNAi to suppress its roles during two meioses of mouse oocytes. Immunocytochemistry and chromosome spread were used to evaluate phenotypes. The exogenous Sgo1 overexpression kept homologous chromosomes and sister <span class="hlt">chromatids</span> not to separate in meiosis I and meiosis II, respectively, while the Sgo1 RNAi promoted premature separation of sister <span class="hlt">chromatids</span>. Conclusions Our results reveal that prevention of premature separation of sister <span class="hlt">chromatids</span> in meiosis I requires the retention of centromeric Sgo1, while normal separation of sister <span class="hlt">chromatids</span> in meiosis II requires loss of centromeric Sgo1. PMID:18949044</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=461013','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=461013"><span id="translatedtitle">Effectiveness of a heat and moisture <span class="hlt">exchanger</span> in preventing hyperpnoea <span class="hlt">induced</span> bronchoconstriction in subjects with asthma.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gravelyn, T R; Capper, M; Eschenbacher, W L</p> <p>1987-01-01</p> <p>The effect of a heat and moisture <span class="hlt">exchanger</span>, a device with hygroscopic material for conditioning inspired air, on hyperpnoea <span class="hlt">induced</span> bronchoconstriction was studied in nine non-smoking volunteers with asthma, aged 19-32 years. Each had previously shown an increase of at least 100% in specific airways resistance (sRaw) to isocapnic hyperpnoea with dry air. On two separate days the subject performed isocapnic hyperpnoea with dry air at 60-70 l min-1 for five minutes. Before, immediately after, and five minutes after completion of a test sRaw measurements were made. Heat and moisture <span class="hlt">exchangers</span> were placed in the breathing circuit on one of the two days. All subjects had an increase in sRaw of 100% or more without the heat and moisture <span class="hlt">exchangers</span> (average increase 300%) but were protected from bronchoconstriction with the devices in place (average increase 7%) (p less than 0.005). The <span class="hlt">exchanger</span>'s resistance to airflow was less than 1 cm H2O for flow rates of 100 l min-1. A heat and moisture <span class="hlt">exchanger</span> designed as a facemask or mouthpiece may allow a person with asthma to exercise without the need for prophylactic drugs. PMID:3424269</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26159362','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26159362"><span id="translatedtitle">Paramagnetic molecule <span class="hlt">induced</span> strong antiferromagnetic <span class="hlt">exchange</span> coupling on a magnetic tunnel junction based molecular spintronics device.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tyagi, Pawan; Baker, Collin; D'Angelo, Christopher</p> <p>2015-07-31</p> <p>This paper reports our Monte Carlo (MC) studies aiming to explain the experimentally observed paramagnetic molecule <span class="hlt">induced</span> antiferromagnetic coupling between ferromagnetic (FM) electrodes. Recently developed magnetic tunnel junction based molecular spintronics devices (MTJMSDs) were prepared by chemically bonding the paramagnetic molecules between the FM electrodes along the tunnel junction's perimeter. These MTJMSDs exhibited molecule-<span class="hlt">induced</span> strong antiferromagnetic coupling. We simulated the 3D atomic model analogous to the MTJMSD and studied the effect of molecule's magnetic couplings with the two FM electrodes. Simulations show that when a molecule established ferromagnetic coupling with one electrode and antiferromagnetic coupling with the other electrode, then theoretical results effectively explained the experimental findings. Our studies suggest that in order to align MTJMSDs' electrodes antiparallel to each other, the <span class="hlt">exchange</span> coupling strength between a molecule and FM electrodes should be ∼50% of the interatomic <span class="hlt">exchange</span> coupling for the FM electrodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1456524','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1456524"><span id="translatedtitle">A Segmental Deletion Series Generated by Sister-<span class="hlt">Chromatid</span> Transposition of Ac Transposable Elements in Maize</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Jianbo; Peterson, Thomas</p> <p>2005-01-01</p> <p>Certain configurations of maize Ac/Ds transposon termini can undergo alternative transposition reactions leading to chromosome breakage and various types of stable chromosome rearrangements. Here, we show that a particular allele of the maize p1 gene containing an intact Ac element and a nearby terminally deleted Ac element (fAc) can undergo sister-<span class="hlt">chromatid</span> transposition (SCT) reactions that generate large flanking deletions. Among 35 deletions characterized, all begin at the Ac termini in the p1 gene and extend to various flanking sites proximal to p1. The deletions range in size from the smallest of 12,567 bp to the largest of >4.6 cM; >80% of the deletions removed the p2 gene, a paralog of p1 located ∼60 kb from p1 in the p1-vv allele and its derivatives. Sequencing of representative cases shows that the deletions have precise junctions between the transposon termini and the flanking genomic sequences. These results show that SCT events can efficiently generate interstitial deletions that are useful for in vivo dissection of local genome regions and for the rapid correlation of genetic and physical maps. Finally, we discuss evidence suggesting that deletions <span class="hlt">induced</span> by alternative transposition reactions can occur at other genomic loci, indicating that this mechanism may have had a significant impact on genome evolution. PMID:15965263</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16217644','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16217644"><span id="translatedtitle">Space radiation does not <span class="hlt">induce</span> a significant increase of intrachromosomal <span class="hlt">exchanges</span> in astronauts' lymphocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Horstmann, M; Durante, M; Johannes, C; Pieper, R; Obe, G</p> <p>2005-12-01</p> <p>Chromosome aberration analysis in astronauts has been used to provide direct, biologically motivated estimates of equivalent doses and risk associated to cosmic radiation exposure during space flight. However, the past studies concentrated on measurements of dicentrics and translocations, while chromosome intrachanges (inversions) have never been measured in astronauts' samples. Recent data reported in the literature suggest that densely ionizing radiation can <span class="hlt">induce</span> a large fraction of intrachanges, thus leading to the suspicion that interchanges grossly underestimate the cosmic radiation-<span class="hlt">induced</span> cytogenetic damage in astronauts. We have analyzed peripheral blood lymphocytes from 11 astronauts involved in short- or long-term space flights in low-Earth orbit using high-resolution multicolor banding to assess the frequency of intrachromosomal <span class="hlt">exchanges</span> in both pre- and post-flight samples. We did not detect any inversions in chromosome 5 from a total of 2800 cells in astronauts' blood. In addition, no complex type <span class="hlt">exchanges</span> were found in a total of 3590 astronauts' lymphocytes analyzed by multifluor fluorescence in situ hybridisation. We conclude that, within the statistical power of this study, the analysis of interchanges for biological dosimetry in astronauts does not significantly underestimate the space radiation-<span class="hlt">induced</span> cytogenetic damage, and complex-type <span class="hlt">exchanges</span> or intrachanges have limited practical use for biodosimetry at very low doses. PMID:16217644</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16217644','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16217644"><span id="translatedtitle">Space radiation does not <span class="hlt">induce</span> a significant increase of intrachromosomal <span class="hlt">exchanges</span> in astronauts' lymphocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Horstmann, M; Durante, M; Johannes, C; Pieper, R; Obe, G</p> <p>2005-12-01</p> <p>Chromosome aberration analysis in astronauts has been used to provide direct, biologically motivated estimates of equivalent doses and risk associated to cosmic radiation exposure during space flight. However, the past studies concentrated on measurements of dicentrics and translocations, while chromosome intrachanges (inversions) have never been measured in astronauts' samples. Recent data reported in the literature suggest that densely ionizing radiation can <span class="hlt">induce</span> a large fraction of intrachanges, thus leading to the suspicion that interchanges grossly underestimate the cosmic radiation-<span class="hlt">induced</span> cytogenetic damage in astronauts. We have analyzed peripheral blood lymphocytes from 11 astronauts involved in short- or long-term space flights in low-Earth orbit using high-resolution multicolor banding to assess the frequency of intrachromosomal <span class="hlt">exchanges</span> in both pre- and post-flight samples. We did not detect any inversions in chromosome 5 from a total of 2800 cells in astronauts' blood. In addition, no complex type <span class="hlt">exchanges</span> were found in a total of 3590 astronauts' lymphocytes analyzed by multifluor fluorescence in situ hybridisation. We conclude that, within the statistical power of this study, the analysis of interchanges for biological dosimetry in astronauts does not significantly underestimate the space radiation-<span class="hlt">induced</span> cytogenetic damage, and complex-type <span class="hlt">exchanges</span> or intrachanges have limited practical use for biodosimetry at very low doses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25758355','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25758355"><span id="translatedtitle">Na(+)/H (+) <span class="hlt">exchanger</span> isoform 1 <span class="hlt">induced</span> osteopontin expression in cardiomyocytes involves NFAT3/Gata4.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mlih, Mohamed; Abdulrahman, Nabeel; Gadeau, Alain-Pierre; Mohamed, Iman A; Jaballah, Maiy; Mraiche, Fatima</p> <p>2015-06-01</p> <p>Osteopontin (OPN), a multifunctional glycophosphoprotein, has been reported to contribute to the development and progression of cardiac remodeling and hypertrophy. Cardiac-specific OPN knockout mice were protected against hypertrophy and fibrosis mediated by Ang II. Recently, transgenic mice expressing the active form of the Na(+)/H(+) <span class="hlt">exchanger</span> isoform 1 (NHE1) developed spontaneous hypertrophy in association with elevated levels of OPN. The mechanism by which active NHE1 <span class="hlt">induces</span> OPN expression and contributes to the hypertrophic response remains unclear. To validate whether expression of the active form of NHE1 <span class="hlt">induces</span> OPN, cardiomyocytes were stimulated with Ang II, a known <span class="hlt">inducer</span> of both OPN and NHE1. Ang II <span class="hlt">induced</span> hypertrophy and increased OPN protein expression (151.6 ± 28.19 %, P < 0.01) and NHE1 activity in H9c2 cardiomyoblasts. Ang II-<span class="hlt">induced</span> hypertrophy and OPN protein expression were regressed in the presence of an NHE1 inhibitor, EMD 87580, or a calcineurin inhibitor, FK506. In addition, our results indicated that activation of NHE1-<span class="hlt">induced</span> NFAT3 translocation into the nucleus and a significant activation of the transcription factor Gata4 (NHE1: 149 ± 28 % of control, P < 0.05). NHE1-<span class="hlt">induced</span> activation of Gata4 was inhibited by FK506. In summary, our results suggest that activation of NHE1 <span class="hlt">induces</span> hypertrophy through the activation of NFAT3/Gata4 and OPN expression. PMID:25758355</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=indian+AND+chemical+AND+society&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=79427544&CFTOKEN=14347261','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=indian+AND+chemical+AND+society&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=79427544&CFTOKEN=14347261"><span id="translatedtitle">ON THE WIND-<span class="hlt">INDUCED</span> <span class="hlt">EXCHANGE</span> BETWEEN INDIAN RIVER BAY, DELAWARE AND THE ADJACENT CONTINENTAL SHELF. (R826945)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><p>The structure of the wind-<span class="hlt">induced</span> <span class="hlt">exchange</span> between Indian River Bay, Delaware and the adjacent continental shelf is examined based on current measurements made at the Indian River Inlet which represents the only conduit of <span class="hlt">exchange</span> between the bay and the coastal ocean. Local ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJD...70..120H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJD...70..120H"><span id="translatedtitle">The weakening of fermionization of one dimensional spinor Bose gases <span class="hlt">induced</span> by spin-<span class="hlt">exchange</span> interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hao, Yajiang</p> <p>2016-05-01</p> <p>We investigate the ground state density distributions of anti-ferromagnetic spin-1 Bose gases in a one dimensional harmonic potential in the full interacting regimes. The ground state is obtained by diagonalizing the Hamiltonian in the Hilbert space composed of the lowest eigenstates of noninteracting Bose gas and spin components. The study reveals that in the situation of a weak spin-dependent interaction the total density profiles evolve from a Gaussian-like distribution to a Fermi-like shell structure of N peaks with the increasing of spin-independent interaction. The increasing spin-<span class="hlt">exchange</span> interaction always weakens the fermionization of the density distribution such that the total density profiles show the shell structure of less peaks and even show single peak structure in the limit of the strong spin-<span class="hlt">exchange</span> interaction. The weakening of fermionization results from the formation of composite atoms <span class="hlt">induced</span> by the spin-<span class="hlt">exchange</span> interaction. It is also shown that phase separation occurs for the spinor Bose gas with a weak spin-<span class="hlt">exchange</span> interaction, meanwhile the spin-independent interaction is strong.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25704114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25704114"><span id="translatedtitle">Nutritional stress <span class="hlt">induces</span> <span class="hlt">exchange</span> of cell material and energetic coupling between bacterial species.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Benomar, Saida; Ranava, David; Cárdenas, María Luz; Trably, Eric; Rafrafi, Yan; Ducret, Adrien; Hamelin, Jérôme; Lojou, Elisabeth; Steyer, Jean-Philippe; Giudici-Orticoni, Marie-Thérèse</p> <p>2015-02-23</p> <p>Knowledge of the behaviour of bacterial communities is crucial for understanding biogeochemical cycles and developing environmental biotechnology. Here we demonstrate the formation of an artificial consortium between two anaerobic bacteria, Clostridium acetobutylicum (Gram-positive) and Desulfovibrio vulgaris Hildenborough (Gram-negative, sulfate-reducing) in which physical interactions between the two partners <span class="hlt">induce</span> emergent properties. Molecular and cellular approaches show that tight cell-cell interactions are associated with an <span class="hlt">exchange</span> of molecules, including proteins, which allows the growth of one partner (D. vulgaris) in spite of the shortage of nutrients. This physical interaction <span class="hlt">induces</span> changes in expression of two genes encoding enzymes at the pyruvate crossroads, with concomitant changes in the distribution of metabolic fluxes, and allows a substantial increase in hydrogen production without requiring genetic engineering. The stress <span class="hlt">induced</span> by the shortage of nutrients of D. vulgaris appears to trigger the interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26075356','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26075356"><span id="translatedtitle">Reconstitution of mitotic <span class="hlt">chromatids</span> with a minimum set of purified factors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shintomi, Keishi; Takahashi, Tatsuro S; Hirano, Tatsuya</p> <p>2015-08-01</p> <p>The assembly of mitotic chromosomes, each composed of a pair of rod-shaped <span class="hlt">chromatids</span>, is an essential prerequisite for accurate transmission of the genome during cell division. It remains poorly understood, however, how this fundamental process might be achieved and regulated in the cell. Here we report an in vitro system in which mitotic <span class="hlt">chromatids</span> can be reconstituted by mixing a simple substrate with only six purified factors: core histones, three histone chaperones (nucleoplasmin, Nap1 and FACT), topoisomerase II (topo II) and condensin I. We find that octameric nucleosomes containing the embryonic variant H2A.X-F are highly susceptible to FACT and function as the most productive substrate for subsequent actions of topo II and condensin I. Cdk1 phosphorylation of condensin I is the sole mitosis-specific modification required for <span class="hlt">chromatid</span> reconstitution. This experimental system will enhance our understanding of the mechanisms of action of individual factors and their cooperation during this process. PMID:26075356</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RaPC..118...35K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RaPC..118...35K"><span id="translatedtitle">Polymeric nanocomposite proton <span class="hlt">exchange</span> membranes prepared by radiation-<span class="hlt">induced</span> polymerization for direct methanol fuel cell</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Young-Seok; Seo, Kwang-Seok; Choi, Seong-Ho</p> <p>2016-01-01</p> <p>The vinyl group-modified montmorillonite clay (F-MMT), vinyl group-modified graphene oxide (F-GO), and vinyl group-modified multi-walled carbon nanotube (F-MWNT) were first prepared by ion <span class="hlt">exchange</span> reaction of 1-[(4-ethylphenyl)methyl]-3-butyl-imidazolium chloride in order to use the materials for protection against methanol cross-over in direct methanol fuel cell (DMFC) membrane. Then polymeric nanocomposite membranes with F-MMT, F-GO, and F-MWNT were prepared by the solvent casting method after radiation-<span class="hlt">induced</span> polymerization of vinyl monomers in water-methanol mixture solvents. The proton conductivity, water uptake, ion-<span class="hlt">exchange</span> capacity, methanol permeability, and DMFC performance of the polymeric nanocomposite membranes with F-MMT, F-GO, and F-MWNT were evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308052','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308052"><span id="translatedtitle"><span class="hlt">Exchange-Induced</span> Relaxation in the Presence of a Fictitious Field</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sorce, Dennis J.; Mangia, Silvia; Liimatainen, Timo; Garwood, Michael; Michaeli, Shalom</p> <p>2014-01-01</p> <p>In the present study we derive a solution for two site fast <span class="hlt">exchange-induced</span> relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast <span class="hlt">exchange</span> regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2. PMID:24911888</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21562695','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562695"><span id="translatedtitle">POLARIZATION OF THE CHARGE-<span class="hlt">EXCHANGE</span> X-RAYS <span class="hlt">INDUCED</span> IN THE HELIOSPHERE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gacesa, M.; Kharchenko, V.; Mueller, H.-R.; Cote, R.</p> <p>2011-05-10</p> <p>We report results of a theoretical investigation of polarization of the X-ray emissions <span class="hlt">induced</span> in charge-<span class="hlt">exchange</span> collisions of fully stripped solar wind (SW) ions C{sup 6+} and O{sup 8+} with the heliospheric hydrogen atoms. The polarization of X-ray emissions has been computed for line-of-sight observations within the ecliptic plane as a function of SW ion velocities, including a range of velocities corresponding to the slow and fast SW, and coronal mass ejections. To determine the variability of polarization of heliospheric X-ray emissions, the polarization has been computed for solar minimum conditions with self-consistent parameters of the SW plasma and heliospheric gas and compared with the polarization calculated for an averaged solar activity. We predict the polarization of charge-<span class="hlt">exchange</span> X-rays to be between 3% and 8%, depending on the line-of-sight geometry, SW ion velocity, and the selected emission lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MAR.A7005L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MAR.A7005L"><span id="translatedtitle">Magnetization in Intrinsic Topological Insulators <span class="hlt">Induced</span> by <span class="hlt">Exchange</span> Interaction with Ferromagnetic Insulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauter, Valeria; Katmis, Ferhat; Assaf, Badih; Heiman, Don; Moodera, Jagadeesh</p> <p>2015-03-01</p> <p>We examine the magnetic proximity-<span class="hlt">induced</span> symmetry breaking via the <span class="hlt">exchange</span> interaction in heterostructures of the topological insulator (TI) Bi2Se3 and the ferromagnetic insulator (FMI) EuS. We observed the emergence of a ferromagnetic phase in TI with the excess of magnetic moment at the interface using depth and element sensitive Polarized Neutron Reflectometry (PNR). We find that the magnetization, penetrating into the TI originates through <span class="hlt">exchange</span> interaction, without structural perturbation at the interface. Due to the different interlayer <span class="hlt">exchange</span> coupling as well as the properties of the bulk and surface magnetizations, we investigated several different heterostructures after cooling in zero field (ZFC) and in an external magnetic field (FC). The significantly enhanced magnetic properties of the heterostructures as revealed by the PNR studies, as well as the temperature and external magnetic field dependence will be presented. This work was supported by the Scientific User Facilities Division, BES, DOE, NSF ECCS-1402738, DMR-1207469, ONR N00014-13-1-0301.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25962614','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25962614"><span id="translatedtitle">The effects of oxygen <span class="hlt">induced</span> pulmonary vasoconstriction on bedside measurement of pulmonary gas <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weinreich, Ulla M; Thomsen, Lars P; Rees, Stephen E; Rasmussen, Bodil S</p> <p>2016-04-01</p> <p>In patients with respiratory failure measurements of pulmonary gas <span class="hlt">exchange</span> are of importance. The bedside automatic lung parameter estimator (ALPE) of pulmonary gas <span class="hlt">exchange</span> is based on changes in inspired oxygen (FiO2) assuming that these changes do not affect pulmonary circulation. This assumption is investigated in this study. Forty-two out of 65 patients undergoing coronary artery bypass grafting (CABG) had measurements of mean pulmonary arterial pressure (MPAP), cardiac output and pulmonary capillary wedge pressure thus enabling the calculation of pulmonary vascular resistance (PVR) at each FiO2 level. The research version of ALPE was used and FiO2 was step-wise reduced a median of 0.20 and ultimately returned towards baseline values, allowing 6-8 min' steady state period at each of 4-6 levels before recording the oxygen saturation (SpO2). FiO2 reduction led to median decrease in SpO2 from 99 to 92 %, an increase in MPAP of 4 mmHg and an increase in PVR of 36 dyn s cm(-5). Changes were immediately reversed on returning FiO2 towards baseline. In this study changes in MPAP and PVR are small and immediately reversible consistent with small changes in pulmonary gas <span class="hlt">exchange</span>. This indicates that mild deoxygenation <span class="hlt">induced</span> pulmonary vasoconstriction does not have significant influences on the ALPE parameters in patients after CABG.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198866','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198866"><span id="translatedtitle">Uncoupled surface spin <span class="hlt">induced</span> <span class="hlt">exchange</span> bias in α-MnO2 nanowires</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Wenxian; Zeng, Rong; Sun, Ziqi; Tian, Dongliang; Dou, Shixue</p> <p>2014-01-01</p> <p>We have studied the microstructure, surface states, valence fluctuations, magnetic properties, and <span class="hlt">exchange</span> bias effect in MnO2 nanowires. High purity α-MnO2 rectangular nanowires were synthesized by a facile hydrothermal method with microwave-assisted procedures. The microstructure analysis indicates that the nanowires grow in the [0 0 1] direction with the (2 1 0) plane as the surface. Mn3+ and Mn2+ ions are not found in the system by X-ray photoelectron spectroscopy. The effective magnetic moment of the manganese ions fits in with the theoretical and experimental values of Mn4+ very well. The uncoupled spins in 3d3 orbitals of the Mn4+ ions in MnO6 octahedra on the rough surface are responsible for the net magnetic moment. Spin glass behavior is observed through magnetic measurements. Furthermore, the <span class="hlt">exchange</span> bias effect is observed for the first time in pure α-MnO2 phase due to the coupling of the surface spin glass with the antiferromagnetic α-MnO2 matrix. These α-MnO2 nanowires, with a spin-glass-like behavior and with an <span class="hlt">exchange</span> bias effect excited by the uncoupled surface spins, should therefore inspire further study concerning the origin, theory, and applicability of surface structure <span class="hlt">induced</span> magnetism in nanostructures. PMID:25319531</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP43C3583L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP43C3583L"><span id="translatedtitle">Hyporheic <span class="hlt">exchange</span> <span class="hlt">induced</span> by channel-spanning obstacles in a coarse, highly-permeable laboratory streambed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lichtner, D.; Best, J.; Blois, G.; Kim, T.; Christensen, K. T.</p> <p>2014-12-01</p> <p>Knowledge of flow over and through a porous streambed is essential to understanding hyporheic <span class="hlt">exchange</span> in coarse gravel-bed rivers, where turbulence in the stream flow can penetrate significantly into the streambed. To study the turbulent momentum <span class="hlt">exchange</span> between a stream and gravel streambed, laboratory experiments were conducted in a 2.5 m long refractive-index matching (RIM) laboratory flume. A flat gravel bed was simulated using cubically packed acrylic spheres (Ds = 1.27 cm) with a refractive index, RI = 1.495, that matched that of the NaI solution in the flume. Thus, optical access to the pore spaces could be gained, and the flow field from the near-bed and into the pore spaces could be measured with particle image velocimetry (PIV). Dense 2-D velocity vector fields were measured for two bed configurations: (1) a flat, porous, bed composed of three layers of spheres and (2) a flat bed with a cylinder (Dc = 1.27 cm) placed atop it, to <span class="hlt">induce</span> hyporheic <span class="hlt">exchange</span> in the manner of a channel-spanning large woody debris. The flow over and through the bed produced by the cylinder is found to be dramaticallydifferent from that associated with a flat bed. The mean velocity field produced by the cylinder exhibited strong flow downwelling in the pore space immediately upstream of the cylinder and upwelling several pore spaces downstream. In particular, the shear layer separating from the cylinder remained parallel to the bed from the point of flow separation to the edge of the field of view, instead of reattaching several grain diameters downstream. The cylinder also promoted increased vertical momentum <span class="hlt">exchange</span> as suggested by turbulent kinetic energy maps.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25445045','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25445045"><span id="translatedtitle">Gram-negative endotoxin lipopolysaccharide <span class="hlt">induces</span> cardiac hypertrophy: detrimental role of Na(+)-Ca(2+) <span class="hlt">exchanger</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Magi, Simona; Nasti, Annamaria Assunta; Gratteri, Santo; Castaldo, Pasqualina; Bompadre, Stefano; Amoroso, Salvatore; Lariccia, Vincenzo</p> <p>2015-01-01</p> <p>Several molecular pathways involved in the development of cardiac hypertrophy are triggered by perturbation of intracellular Ca(2+) homeostasis. Within the heart, Na(+)/Ca(2+) <span class="hlt">exchanger</span> 1 (NCX1) is one of the main determinant in controlling Ca(2+) homeostasis. In cardiac hypertrophy and heart failure NCX1 expression and activity have been reported to be altered. It has been shown that chronic bacterial infections (sepsis, endocarditis, and myocarditis) can promote cardiac hypertrophy. Bacterial stressors, such as the Gram-negative endotoxin lipopolysaccharide (LPS), can directly or indirectly affect intracellular Ca(2+) homeostasis in the heart and <span class="hlt">induce</span> the development of cardiac hypertrophy. The present study aimed at evaluating the potential link between the signal pathways activated in LPS-exposed myocytes and NCX1. In the whole rat heart, LPS perfusion <span class="hlt">induced</span> an early hypertrophy response during which NCX1 expression significantly increased. Notably, all these changes were completely prevented by the NCX inhibitor SN-6. We further dissect the role of NCX1 in the LPS-<span class="hlt">induced</span> hypertrophic response in an in vitro cardiac model based on two H9c2 cardiomyoblast clones, namely H9c2-WT (lacking endogenous NCX1 expression) and H9c2-NCX1 (stably transfected with a functional NCX1). H9c2-NCX1 were more susceptible than H9c2-WT to develop a hypertrophic phenotype, and they displayed a significant increase in NCX1 expression and function after LPS treatment. SN-6 completely counteracted both hypertrophic response and <span class="hlt">exchanger</span> alterations <span class="hlt">induced</span> by LPS in H9c2-NCX1 cells, but it had no effects on H9c2-WT. Collectively, our results suggest that NCX1 plays a critical role in promoting myocardial hypertrophy triggered by LPS. PMID:25445045</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9568118','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9568118"><span id="translatedtitle">Genotoxicity of polycyclic musk fragrances in the sister-<span class="hlt">chromatid</span> <span class="hlt">exchange</span> test.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kevekordes, S; Mersch-Sundermann, V; Diez, M; Bolten, C; Dunkelberg, H</p> <p>1998-01-01</p> <p>The synthetic polycyclic musk fragrance compounds Galaxolide (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclo-penta-(g)-2-++ +benzopyrane, Tonalide (7-acetyl-1,1,3,4,4,6-hexamerthyltetraline), Celestolide (4-acetyl-1,1-dimethyl-6-tert, butylindane), Phantolide (6-acetyl-1,1,2,3,3,5-hexamethylindane), Cashmeran (6,7-dihydro-1,1,2,3,3-pentamethyl-4-(5H) indanone) and Traseolide (5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane) are widely used as fragrance ingredients in perfumes, lotions and detergents; as food additives in cigarettes and fish baits. Several studies identified polycyclic musk fragrances in aquatic environment samples, human milk and human adipose tissue as highly lipophil with human lymphocytes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6220543','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6220543"><span id="translatedtitle">Review of the international symposium, sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>: twenty-five years of experimental research</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tice, R.R.; Lambert, B.; Morimoto, Kanehisa; Hollaender, A.</p> <p>1983-01-01</p> <p>The purpose of this symposium was to honor initial research at Brookhaven by bringing internationally recognized leaders in the fields of genetics, cytogenetics, carcinogenesis, mutagenesis, radiation biology, toxicology, and environmental health together into an open forum to present and discuss: (1) current knowledge of the induction and formation of SCEs and their relationship to other biological endpoints, including carcinogenesis, mutagenesis, transformation, clastogenesis, DNA damage and repair, and cellular toxicity; (2) the optimal strategies for the utilization of SCEs in genetic toxicology testing schemes involving in vitro and in vivo exposure situations; (3) the most valid statistical methods for analyzing SCE data obtained from cells in culture, from cells in intact organisms, and from cells in humans; (4) the relevance of SCEs as an indicator of human disease states, both inherited and acquired, and of progress in disease treatment; and (5) the use of SCEs as an indicator of human exposure to genotoxic agents and their relevance as a prognosticator of future adverse health outcomes. This report summarizes the presentations. 7 references. (ACR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol16/pdf/CFR-2011-title40-vol16-sec79-65.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol16/pdf/CFR-2011-title40-vol16-sec79-65.pdf"><span id="translatedtitle">40 CFR 79.65 - In vivo sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> assay.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... which does not produce either a statistically significant dose-related increase in the number of SCE or... in this assay, but use of that species will be justified by the tester. (4) Animal number and sex. At... test substance may be used, the maximum tolerated dose or that producing some indication of toxicity...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol16/pdf/CFR-2010-title40-vol16-sec79-65.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol16/pdf/CFR-2010-title40-vol16-sec79-65.pdf"><span id="translatedtitle">40 CFR 79.65 - In vivo sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> assay.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... which does not produce either a statistically significant dose-related increase in the number of SCE or... in this assay, but use of that species will be justified by the tester. (4) Animal number and sex. At... test substance may be used, the maximum tolerated dose or that producing some indication of toxicity...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014LSSR....2...23Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014LSSR....2...23Z"><span id="translatedtitle">Proximity within interphase chromosome contributes to the breakpoint distribution in radiation-<span class="hlt">induced</span> intrachromosomal <span class="hlt">exchanges</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu</p> <p>2014-07-01</p> <p>Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome 3 in human mammary epithelial cells after exposures to either low- or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome <span class="hlt">exchange</span> event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-<span class="hlt">induced</span> chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome <span class="hlt">exchanges</span> involving breaks on the p-arm and in the centromere region of chromosome 3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-<span class="hlt">induced</span> chromosome aberrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986pvp..conf.....H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986pvp..conf.....H"><span id="translatedtitle">Shellside flow-<span class="hlt">induced</span> tube vibration in typical heat <span class="hlt">exchanger</span> configurations: Overview of a research program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halle, H.; Chenoweth, J. M.; Wambsganss, M. W.</p> <p></p> <p>A comprehensive research program is being conducted to develop the necessary criteria to assist designers and operators of shell-and-tube heat <span class="hlt">exchangers</span> to avoid detrimental flow-<span class="hlt">induced</span> tube vibration. This paper presents an overview of the insights gained from shellside water-flow testing on a horizontal, industrial-sized test <span class="hlt">exchanger</span> that can be configured in many ways using interchangeable tube bundles and replaceable nozzles. Nearly 50 different configurations have been tested representing various combinations of triangular, square, rotated-triangular, and rotated-square tubefield layouts; odd and even numbers of crosspasses; and both single- and double-segmental baffles with different cut sizes and orientations. The results are generally consistent with analytical relationships that predict tube vibration response by the combined reinforcing effect of the vibration mode shape and flow velocity distribution. An understanding of the vibration and instability performance is facilitated by recognizing that the excitation is <span class="hlt">induced</span> by three separate, though sometimes interacting, flow conditions. These are the crossflows that generate classic fluidelastic instabilities in the interior of the tube bundle, the entrance and exit bundle flow from and into the shell nozzles, and the localized high velocity bypass and leakage stream flows. The implications to design and/or possible field remedies to avoid vibration problems are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2969851','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2969851"><span id="translatedtitle">BubR1- and Polo-Coated DNA Tethers Facilitate Poleward Segregation of Acentric <span class="hlt">Chromatids</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Royou, Anne; Gagou, Mary E.; Karess, Roger; Sullivan, William</p> <p>2010-01-01</p> <p>Summary The mechanisms that safeguard cells against chromosomal instability (CIN) are of great interest, as CIN contributes to tumorigenesis. To gain insight into these mechanisms, we studied the behavior of cells entering mitosis with damaged chromosomes. We used the endonuclease I-CreI to generate acentric chromosomes in Drosophila larvae. While I-CreI expression produces acentric chromosomes in the majority of neuronal stem cells, remarkably, it has no effect on adult survival. Our live studies reveal that acentric <span class="hlt">chromatids</span> segregate efficiently to opposite poles. The acentric <span class="hlt">chromatid</span> poleward movement is mediated through DNA tethers decorated with BubR1, Polo, INCENP, and Aurora-B. Reduced BubR1 or Polo function results in abnormal segregation of acentric <span class="hlt">chromatids</span>, a decrease in acentric chromosome tethering, and a great reduction in adult survival. We propose that BubR1 and Polo facilitate the accurate segregation of acentric <span class="hlt">chromatids</span> by maintaining the integrity of the tethers that connect acentric chromosomes to their centric partners. PMID:20141837</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1470908','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1470908"><span id="translatedtitle">The origin recognition complex links replication, sister <span class="hlt">chromatid</span> cohesion and transcriptional silencing in Saccharomyces cerevisiae.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Suter, Bernhard; Tong, Amy; Chang, Michael; Yu, Lisa; Brown, Grant W; Boone, Charles; Rine, Jasper</p> <p>2004-01-01</p> <p>Mutations in genes encoding the origin recognition complex (ORC) of Saccharomyces cerevisiae affect initiation of DNA replication and transcriptional repression at the silent mating-type loci. To explore the function of ORC in more detail, a screen for genetic interactions was undertaken using large-scale synthetic lethal analysis. Combination of orc2-1 and orc5-1 alleles with the complete set of haploid deletion mutants revealed synthetic lethal/sick phenotypes with genes involved in DNA replication, chromatin structure, checkpoints, DNA repair and recombination, and other genes that were unexpected on the basis of previous studies of ORC. Many of these genetic interactions are shared with other genes that are involved in initiation of DNA replication. Strong synthetic interactions were demonstrated with null mutations in genes that contribute to sister <span class="hlt">chromatid</span> cohesion. A genetic interaction between orc5-1 and the cohesin mutant scc1-73 suggested that ORC function contributes to sister <span class="hlt">chromatid</span> cohesion. Thus, comprehensive screening for genetic interactions with a replication gene revealed a connection between initiation of DNA replication and sister <span class="hlt">chromatid</span> cohesion. Further experiments linked sister <span class="hlt">chromatid</span> cohesion genes to silencing at mating-type loci and telomeres. PMID:15238513</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CPL...661...48B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CPL...661...48B"><span id="translatedtitle">Anion-<span class="hlt">induced</span> <span class="hlt">exchange</span> interactions in binuclear complexes of Cu(II) with flexible hexadentate bispicolylamidrazone ligands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baryshnikov, Gleb V.; Minaev, Boris F.; Baryshnikova, Alina A.; Ågren, Hans</p> <p>2016-09-01</p> <p>Two recently synthesized copper(II) complexes with spacer-armed bispicolylamidrazone ligands have been theoretically studied at the density functional theory (DFT) level accounting for empirical dispersion correction and intrinsic anionic environment by perchlorate ions. The <span class="hlt">exchange</span> parameter between the open-shell singlet and triplet states of the studied complexes has been estimated by broken symmetry DFT calculations. The mechanism of spin-spin <span class="hlt">exchange</span> interaction between the unpaired electrons via the σ-bond aliphatic chain (Gusev et al., 2015) is confirmed. Instead, a anion-<span class="hlt">induced</span> mechanism is proposed which means that the anionic grid participates in the <span class="hlt">exchange</span> interaction between the unpaired electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4139276','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4139276"><span id="translatedtitle">IL-17A <span class="hlt">Induces</span> Pendrin Expression and Chloride-Bicarbonate <span class="hlt">Exchange</span> in Human Bronchial Epithelial Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Adams, Kelly M.; Abraham, Valsamma; Spielman, Daniel; Kolls, Jay K.; Rubenstein, Ronald C.; Conner, Gregory E.; Cohen, Noam A.; Kreindler, James L.</p> <p>2014-01-01</p> <p>The epithelium plays an active role in the response to inhaled pathogens in part by responding to signals from the immune system. Epithelial responses may include changes in chemokine expression, increased mucin production and antimicrobial peptide secretion, and changes in ion transport. We previously demonstrated that interleukin-17A (IL-17A), which is critical for lung host defense against extracellular bacteria, significantly raised airway surface pH in vitro, a finding that is common to a number of inflammatory diseases. Using microarray analysis of normal human bronchial epithelial (HBE) cells treated with IL-17A, we identified the electroneutral chloride-bicarbonate <span class="hlt">exchanger</span> Pendrin (SLC26A4) as a potential mediator of this effect. These data were verified by real-time, quantitative PCR that demonstrated a time-dependent increase in Pendrin mRNA expression in HBE cells treated with IL-17A up to 48 h. Using immunoblotting and immunofluorescence, we confirmed that Pendrin protein expression is increased in IL-17 treated HBE cells and that it is primarily localized to the mucosal surface of the cells. Functional studies using live-cell fluorescence to measure intracellular pH demonstrated that IL-17A <span class="hlt">induced</span> chloride-bicarbonate <span class="hlt">exchange</span> in HBE cells that was not present in the absence of IL-17A. Furthermore, HBE cells treated with short interfering RNA against Pendrin showed substantially reduced chloride-bicarbonate <span class="hlt">exchange</span>. These data suggest that Pendrin is part of IL-17A-dependent epithelial changes and that Pendrin may therefore be a therapeutic target in IL-17A-dependent lung disease. PMID:25141009</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=Breaks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DBreaks','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=Breaks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DBreaks"><span id="translatedtitle">Rejoining of isochromatid breaks <span class="hlt">induced</span> by heavy ions in G2-phase normal human fibroblasts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Ito, H.; Wu, H.; Cucinotta, F. A.</p> <p>2001-01-01</p> <p>We reported previously that exposure of normal human fibroblasts in G2 phase of the cell cycle to high-LET radiation produces a much higher frequency of isochromatid breaks than exposure to gamma rays. We concluded that an increase in the production of isochromatid breaks is a signature of initial high-LET radiation-<span class="hlt">induced</span> G2-phase damage. In this paper, we report the repair kinetics of isochromatid breaks <span class="hlt">induced</span> by high-LET radiation in normal G2-phase human fibroblasts. Exponentially growing human fibroblasts (AG1522) were irradiated with gamma rays or energetic carbon (290 MeV/nucleon), silicon (490 MeV/nucleon), or iron (200 MeV/nucleon) ions. Prematurely condensed chromosomes were <span class="hlt">induced</span> by calyculin A after different postirradiation incubation times ranging from 0 to 600 min. Chromosomes were stained with Giemsa, and aberrations were scored in cells at G2 phase. G2-phase fragments, the result of the induction of isochromatid breaks, decreased quickly with incubation time. The curve for the kinetics of the rejoining of <span class="hlt">chromatid</span>-type breaks showed a slight upward curvature with time after exposure to 440 keV/microm iron particles, probably due to isochromatid-isochromatid break rejoining. The formation of <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> after exposure to high-LET radiation therefore appears to be underestimated, because isochromatid-isochromatid <span class="hlt">exchanges</span> cannot be detected. Increased induction of isochromatid breaks and rejoining of isochromatid breaks affect the overall kinetics of <span class="hlt">chromatid</span>-type break rejoining after exposure to high-LET radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5017209','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5017209"><span id="translatedtitle"><span class="hlt">Exchange</span> factors directly activated by cAMP mediate melanocortin 4 receptor-<span class="hlt">induced</span> gene expression</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Glas, Evi; Mückter, Harald; Gudermann, Thomas; Breit, Andreas</p> <p>2016-01-01</p> <p>Gs protein-coupled receptors regulate many vital body functions by activation of cAMP response elements (CRE) via cAMP-dependent kinase A (PKA)-mediated phosphorylation of the CRE binding protein (CREB). Melanocortin 4 receptors (MC4R) are prototypical Gs-coupled receptors that orchestrate the hypothalamic control of food-intake and metabolism. Remarkably, the significance of PKA for MC4R-<span class="hlt">induced</span> CRE-dependent transcription in hypothalamic cells has not been rigorously interrogated yet. In two hypothalamic cell lines, we observed that blocking PKA activity had only weak or no effects on reporter gene expression. In contrast, inhibitors of <span class="hlt">exchange</span> factors directly activated by cAMP-1/2 (EPAC-1/2) mitigated MC4R-<span class="hlt">induced</span> CRE reporter activation and mRNA induction of the CREB-dependent genes c-fos and thyrotropin-releasing hormone. Furthermore, we provide first evidence that extracellular-regulated kinases-1/2 (ERK-1/2) activated by EPACs and not PKA are the elusive CREB kinases responsible for MC4R-<span class="hlt">induced</span> CREB/CRE activation in hypothalamic cells. Overall, these data emphasize the pivotal role of EPACs rather than PKA in hypothalamic gene expression elicited by a prototypical Gs-coupled receptor. PMID:27612207</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27612207','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27612207"><span id="translatedtitle"><span class="hlt">Exchange</span> factors directly activated by cAMP mediate melanocortin 4 receptor-<span class="hlt">induced</span> gene expression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glas, Evi; Mückter, Harald; Gudermann, Thomas; Breit, Andreas</p> <p>2016-01-01</p> <p>Gs protein-coupled receptors regulate many vital body functions by activation of cAMP response elements (CRE) via cAMP-dependent kinase A (PKA)-mediated phosphorylation of the CRE binding protein (CREB). Melanocortin 4 receptors (MC4R) are prototypical Gs-coupled receptors that orchestrate the hypothalamic control of food-intake and metabolism. Remarkably, the significance of PKA for MC4R-<span class="hlt">induced</span> CRE-dependent transcription in hypothalamic cells has not been rigorously interrogated yet. In two hypothalamic cell lines, we observed that blocking PKA activity had only weak or no effects on reporter gene expression. In contrast, inhibitors of <span class="hlt">exchange</span> factors directly activated by cAMP-1/2 (EPAC-1/2) mitigated MC4R-<span class="hlt">induced</span> CRE reporter activation and mRNA induction of the CREB-dependent genes c-fos and thyrotropin-releasing hormone. Furthermore, we provide first evidence that extracellular-regulated kinases-1/2 (ERK-1/2) activated by EPACs and not PKA are the elusive CREB kinases responsible for MC4R-<span class="hlt">induced</span> CREB/CRE activation in hypothalamic cells. Overall, these data emphasize the pivotal role of EPACs rather than PKA in hypothalamic gene expression elicited by a prototypical Gs-coupled receptor. PMID:27612207</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24777198','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24777198"><span id="translatedtitle">High-temperature electromagnons in the magnetically <span class="hlt">induced</span> multiferroic cupric oxide driven by intersublattice <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jones, S P P; Gaw, S M; Doig, K I; Prabhakaran, D; Hétroy Wheeler, E M; Boothroyd, A T; Lloyd-Hughes, J</p> <p>2014-01-01</p> <p>Magnetically <span class="hlt">induced</span> ferroelectric multiferroics present an exciting new paradigm in the design of multifunctional materials, by intimately coupling magnetic and polar order. Magnetoelectricity creates a novel quasiparticle excitation--the electromagnon--at terahertz frequencies, with spectral signatures that unveil important spin interactions. To date, electromagnons have been discovered at low temperature (<70 K) and predominantly in rare-earth compounds such as RMnO3. Here we demonstrate using terahertz time-domain spectroscopy that intersublattice <span class="hlt">exchange</span> in the improper multiferroic cupric oxide (CuO) creates electromagnons at substantially elevated temperatures (213-230 K). Dynamic magnetoelectric coupling can therefore be achieved in materials, such as CuO, that exhibit minimal static cross-coupling. The electromagnon strength and energy track the static polarization, highlighting the importance of the underlying cycloidal spin structure. Polarized neutron scattering and terahertz spectroscopy identify a magnon in the antiferromagnetic ground state, with a temperature dependence that suggests a significant role for biquadratic <span class="hlt">exchange</span>. PMID:24777198</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94e4428K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94e4428K"><span id="translatedtitle"><span class="hlt">Exchange</span> and spin-orbit <span class="hlt">induced</span> phenomena in diluted (Ga,Mn)As from first principles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kudrnovský, J.; Drchal, V.; Turek, I.</p> <p>2016-08-01</p> <p>Physical properties <span class="hlt">induced</span> by <span class="hlt">exchange</span> interactions (Curie temperature and spin stiffness) and spin-orbit coupling (anomalous Hall effect, anisotropic magnetoresistance, and Gilbert damping) in the diluted (Ga,Mn)As ferromagnetic semiconductor are studied from first principles. Recently developed Kubo-Bastin transport theory and nonlocal torque operator formulation of the Gilbert damping as formulated in the tight-binding linear muffin-tin orbital method are used. The first-principles Liechtenstein mapping is employed to construct an effective Heisenberg Hamiltonian and to estimate Curie temperature and spin stiffness in the real-space random-phase approximation. Good agreement of calculated physical quantities with experiments on well-annealed samples containing only a small amount of compensating defects is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55hNB07K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55hNB07K"><span id="translatedtitle">Surface-segregated Si and Ge ultrathin films formed by Ag-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurosawa, Masashi; Ohta, Akio; Araidai, Masaaki; Zaima, Shigeaki</p> <p>2016-08-01</p> <p>We have developed a new method of growing Si or Ge ultrathin films on a Ag(111) surface by using a Ag-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> (ALEX) process toward the creation of 2D honeycomb sheets of Si and Ge, known as silicene and germanene, respectively. In the present paper, we clarify ALEX features, specifically the surface segregation of Si (or Ge) atoms from the underlying substrate, focusing on the annealing temperature and time. Hard X-ray photoelectron spectroscopy analyses demonstrate that surface-segregated Si (or Ge) exists on the Ag surfaces after the epitaxial growth of the Ag layer on Si(111) [or Ge(111)] substrates; the amount of segregated Si (or Ge) can be controlled by a subsequent annealing. Also, we find that the segregation of an ultrathin Si or Ge layer proceeds at an interface between Ag and the AlO x capping layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150009494','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150009494"><span id="translatedtitle">Proximity Within Interphase Chromosome Contributes to the Breakpoint Distribution in Radiation-<span class="hlt">Induced</span> Intrachromosomal <span class="hlt">Exchanges</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu</p> <p>2015-01-01</p> <p>Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome3 in human mammary epithelial cells after exposures to either low-or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome <span class="hlt">exchange</span> event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-<span class="hlt">induced</span> chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome <span class="hlt">exchanges</span> involving breaks on the p-arm and in the centromere region of chromosome3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-<span class="hlt">induced</span> chromosome aberrations. Further investigations suggest that the 3D chromosome folding is cell type and culture condition dependent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1066175','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1066175"><span id="translatedtitle">Gas <span class="hlt">Exchange</span> and Phytoluminography of Single Red Kidney Bean Leaves during Periods of <span class="hlt">Induced</span> Stomatal Oscillations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ellenson, James L.; Raba, Richard M.</p> <p>1983-01-01</p> <p>This report examines the capabilities of a new approach to the study of gas <span class="hlt">exchange</span> and electron transport properties of single, intact leaves. The method combines conventional aspects of analysis with an image intensification system that records the spatial distribution of delayed light emission (DLE) over single leaf surfaces. The combined system was used to investigate physiological perturbations <span class="hlt">induced</span> by exposure of single leaves of Phaseolus vulgaris cv `California Light Red' to a combination of SO2 (0.5 microliters per liter) and ozone (0.1 microliters per liter). Exposure of one-half of a leaf to this combination <span class="hlt">induced</span> DLE and stomatal oscillations, but only in the half of the leaf exposed to the combined gases. Examination of phytoluminographs taken during these oscillations revealed distinct leaf patches where the greatest changes in DLE intensity occurred. This phenomenon is interpreted to be evidence that control of stomatal activity of intact plant leaves occurs within discrete leaf areas defined within the vascular network. Images Fig. 6 PMID:16662989</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH31A2391F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH31A2391F"><span id="translatedtitle">Charge-<span class="hlt">exchange</span> <span class="hlt">Induced</span> Modulation of the Heliosheath Ion Distribution Downstream of the Termination Shock</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fahr, H. J.; Fichtner, H.; Scherer, K.</p> <p>2015-12-01</p> <p>We consider the evolution of the solar wind ion distribution function alongthe plasma flow downstream from the termination shock <span class="hlt">induced</span> by chargeexchange processes with cold interstellar H-atoms. We start from a kineticphase space transport equation valid in the bulk frame of the plasma flowthat takes into account convective changes, cooling processes, energydiffusion and ion injection, and describes solar wind and pick-up ionsas a co-moving, isotropic, joint ion population. From this kinetic transportequation one can ascend to an equation for the pressure moment of the iondistribution function, a so-called pressure transport equation, describingthe evolution of the ion pressure in the comoving rest frame. Assuming thatthe local ion distribution can be represented by an adequate kappa functionwith a kappa parameter that varies with the streamline coordinate, weobtain an ordinary differential equation for kappa as function of thestreamline coordinate s. With this result then we gain the heliosheath iondistribution function downstream of the termination shock. The latter thencan be used to predict the Voyager-2 measured moments of the distributionfunction like ion density and ion temperature, and it can also be used topredict spectral fluxes of ENA`s originating from these ions and registeredby IBEX-Hi and IBEX-Lo.We especially analyse the solar wind ion temperature decreasemeasured by Voyager-2 between the years 2008 to 2011 and try to explain itas a charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> cooling of the ion distribution function duringthe associated ion convection period.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2670183','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2670183"><span id="translatedtitle">Characterization of the components of the putative mammalian sister <span class="hlt">chromatid</span> cohesion complex</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Darwiche, N.; Freeman, L.A.; Strunnikov, A.</p> <p>2009-01-01</p> <p>Establishing and maintaining proper sister <span class="hlt">chromatid</span> cohesion throughout the cell cycle are essential for maintaining genome integrity. To understand how sister <span class="hlt">chromatid</span> cohesion occurs in mammals, we have cloned and characterized mouse orthologs of proteins known to be involved in sister <span class="hlt">chromatid</span> cohesion in other organisms. The cDNAs for the mouse orthologs of SMC1S.c. and SMC3S.c., mSMCB and mSMCD respectively, were cloned and the corresponding transcripts and proteins were characterized. mSMCB and mSMCD are transcribed at similar levels in adult mouse tissues except in testis, which has an excess of mSMCD transcripts. The mSMCB and mSMCD proteins, as well as the PW29 protein, a mouse homolog of Mcd1pS.c./Rad21S.p., form a complex similar to cohesin in X. laevis. mSMCB, mSMCD and PW29 protein levels show no significant cell-cycle dependence. The bulk of the mSMCB, mSMCD and PW29 proteins undergo redistribution from the chromosome vicinity to the cytoplasm during prometaphase and back to the chromatin in telophase. This pattern of intracellular localization suggests a complex role for this group of SMC proteins in chromosome dynamics. The PW29 protein and PCNA, which have both been implicated in sister <span class="hlt">chromatid</span> cohesion, do not colocalize, indicating that these proteins may not function in the same cohesion pathway. Overexpression of a PW29-GFP fusion protein in mouse fibroblasts leads to inhibition of proliferation, implicating this protein and its complex with SMC proteins in the control of mitotic cycle progression. PMID:10375619</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1470669','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1470669"><span id="translatedtitle">Chl1p, a DNA helicase-like protein in budding yeast, functions in sister-<span class="hlt">chromatid</span> cohesion.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Skibbens, Robert V</p> <p>2004-01-01</p> <p>From the time of DNA replication until anaphase onset, sister <span class="hlt">chromatids</span> remain tightly paired along their length. Ctf7p/Eco1p is essential to establish sister-<span class="hlt">chromatid</span> pairing during S-phase and associates with DNA replication components. DNA helicases precede the DNA replication fork and thus will first encounter chromatin sites destined for cohesion. In this study, I provide the first evidence that a DNA helicase is required for proper sister-<span class="hlt">chromatid</span> cohesion. Characterizations of chl1 mutant cells reveal that CHL1 interacts genetically with both CTF7/ECO1 and CTF18/CHL12, two genes that function in sister-<span class="hlt">chromatid</span> cohesion. Consistent with genetic interactions, Chl1p physically associates with Ctf7p/Eco1p both in vivo and in vitro. Finally, a functional assay reveals that Chl1p is critical for sister-<span class="hlt">chromatid</span> cohesion. Within the budding yeast genome, Chl1p exhibits the highest degree of sequence similarity to human CHL1 isoforms and BACH1. Previous studies revealed that human CHLR1 exhibits DNA helicase-like activities and that BACH1 is a helicase-like protein that associates with the tumor suppressor BRCA1 to maintain genome integrity. Our findings document a novel role for Chl1p in sister-<span class="hlt">chromatid</span> cohesion and provide new insights into the possible mechanisms through which DNA helicases may contribute to cancer progression when mutated. PMID:15020404</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1461834','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1461834"><span id="translatedtitle">Genes involved in sister <span class="hlt">chromatid</span> separation and segregation in the budding yeast Saccharomyces cerevisiae.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Biggins, S; Bhalla, N; Chang, A; Smith, D L; Murray, A W</p> <p>2001-01-01</p> <p>Accurate chromosome segregation requires the precise coordination of events during the cell cycle. Replicated sister <span class="hlt">chromatids</span> are held together while they are properly attached to and aligned by the mitotic spindle at metaphase. At anaphase, the links between sisters must be promptly dissolved to allow the mitotic spindle to rapidly separate them to opposite poles. To isolate genes involved in chromosome behavior during mitosis, we microscopically screened a temperature-sensitive collection of budding yeast mutants that contain a GFP-marked chromosome. Nine LOC (loss of cohesion) complementation groups that do not segregate sister <span class="hlt">chromatids</span> at anaphase were identified. We cloned the corresponding genes and performed secondary tests to determine their function in chromosome behavior. We determined that three LOC genes, PDS1, ESP1, and YCS4, are required for sister <span class="hlt">chromatid</span> separation and three other LOC genes, CSE4, IPL1, and SMT3, are required for chromosome segregation. We isolated alleles of two genes involved in splicing, PRP16 and PRP19, which impair alpha-tubulin synthesis thus preventing spindle assembly, as well as an allele of CDC7 that is defective in DNA replication. We also report an initial characterization of phenotypes associated with the SMT3/SUMO gene and the isolation of WSS1, a high-copy smt3 suppressor. PMID:11606525</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3511117','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3511117"><span id="translatedtitle">Legacy of human-<span class="hlt">induced</span> C erosion and burial on soil–atmosphere C <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Van Oost, Kristof; Verstraeten, Gert; Doetterl, Sebastian; Notebaert, Bastiaan; Wiaux, François; Broothaerts, Nils; Six, Johan</p> <p>2012-01-01</p> <p>Carbon <span class="hlt">exchange</span> associated with accelerated erosion following land cover change is an important component of the global C cycle. In current assessments, however, this component is not accounted for. Here, we integrate the effects of accelerated C erosion across point, hillslope, and catchment scale for the 780-km2 Dijle River catchment over the period 4000 B.C. to A.D. 2000 to demonstrate that accelerated erosion results in a net C sink. We found this long-term C sink to be equivalent to 43% of the eroded C and to have offset 39% (17–66%) of the C emissions due to anthropogenic land cover change since the advent of agriculture. Nevertheless, the erosion-<span class="hlt">induced</span> C sink strength is limited by a significant loss of buried C in terrestrial depositional stores, which lagged the burial. The time lag between burial and subsequent loss at this study site implies that the C buried in eroded terrestrial deposits during the agricultural expansion of the last 150 y cannot be assumed to be inert to further destabilization, and indeed might become a significant C source. Our analysis exemplifies that accounting for the non–steady-state C dynamics in geomorphic active systems is pertinent to understanding both past and future anthropogenic global change. PMID:23134723</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5568104','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5568104"><span id="translatedtitle">Studies on biologically <span class="hlt">induced</span> corrosion in heat <span class="hlt">exchanger</span> systems at the Savannah River Plant, Aiken, SC</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pope, D.H.; Soracco, R.J.; Wilde, E.W.</p> <p>1982-07-01</p> <p>Biological fouling and corrosion of stainless steel tubes in the heat <span class="hlt">exchangers</span> in nuclear reactors at the Savannah River Plant have caused decreased heat transfer efficiency and reduced operational life. This report addresses the microbiology and chemistry of the films present on these tubes, and the relation of this data to the corrosion of the tube material (304L stainless steel). Very few microorganisms other than bacteria were found in the biofilm. Bacteria capable of producing H/sub 2/S, organic acids, anaerobic conditions, and slime have all been isolated from these films. All of these have been implicated in corrosion processes. The most remarkable chemical finding was the inability to detect chloride in the film around areas of presumed chloride <span class="hlt">induced</span> stress corrosion cracking. Three model systems were used to test the fouling and corrosion potential of metal specimens under a variety of environmental conditions including various biocide regimes. Using these systems, potential improvements in the use of chlorine as a biocidal agent have been observed. It was also shown that larger bacterial populations (including viable and killed cells) were associated with corroded areas as compared to noncorroded areas on the same specimen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMNH13B1151A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNH13B1151A"><span id="translatedtitle">Climate-<span class="hlt">induced</span> tree mortality: earth system consequences for carbon, energy, and water <span class="hlt">exchanges</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adams, H. D.; Macalady, A.; Breshears, D. D.; Allen, C. D.; Luce, C.; Royer, P. D.; Huxman, T. E.</p> <p>2010-12-01</p> <p> subsurface flow, runoff, groundwater recharge, and streamflow. Under some circumstances there may also be increased flood risks. We hypothesized thresholds of mean annual precipitation and canopy cover reduction identified from the forest harvesting literature as minima that must be exceeded for die-off to noticeably affect hydrologic processes. We note exceptions to these thresholds when snowmelt dominates the watershed hydrology and when mortality affects a single species with a unique hydrologic role. Management options for mitigating die-off effects on ecosystem and earth system processes and implementing post-die-off restoration will likely be limited and costly, requiring ecological and societal adaptation in many areas. As such, climate-<span class="hlt">induced</span> tree mortality poses a significant risk to the current earth system function through altered <span class="hlt">exchanges</span> of carbon, energy, and water between the land surface and atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26242483','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26242483"><span id="translatedtitle">Natural Antioxidants Against Arsenic-<span class="hlt">Induced</span> Genotoxicity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, Munesh; Lalit, Minakshi; Thakur, Rajesh</p> <p>2016-03-01</p> <p>Arsenic is present in water, soil, and air in organic as well as in inorganic forms. However, inorganic arsenic is more toxic than organic and can cause many diseases including cancers in humans. Its genotoxic effect is considered as one of its carcinogenic actions. Arsenic can cause DNA strand breaks, deletion mutations, micronuclei formation, DNA-protein cross-linking, sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span>, and DNA repair inhibition. Evidences indicate that arsenic causes DNA damage by generation of reactive free radicals. Nutritional supplementation of antioxidants has been proven highly beneficial against arsenic genotoxicity in experimental animals. Recent studies suggest that antioxidants protect mainly by reducing excess free radicals via restoring the activities of cellular enzymatic as well as non-enzymatic antioxidants and decreasing the oxidation processes such as lipid peroxidation and protein oxidation. The purpose of this review is to summarize the recent literature on arsenic-<span class="hlt">induced</span> genotoxicity and its mitigation by naturally derived antioxidants in various biological systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=DNA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDNA','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=DNA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDNA"><span id="translatedtitle">Probabilities of radiation-<span class="hlt">induced</span> inter- and intrachromosomal <span class="hlt">exchanges</span> and their dependence on the DNA content of the chromosome</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, H.; Yang, T. C. (Principal Investigator)</p> <p>2001-01-01</p> <p>A biophysical model has been developed that is based on the assumptions that an interphase chromosome occupies a spherical territory and that chromosome <span class="hlt">exchanges</span> are formed by the misrejoining of two DNA double-strand breaks <span class="hlt">induced</span> within a defined interaction distance. The model is used to explain the relative frequencies of inter- and intrachromosomal <span class="hlt">exchanges</span> and the relationship between radiation-<span class="hlt">induced</span> aberrations in individual chromosomes and the DNA content of the chromosome. Although this simple model predicts a higher ratio of inter- to intrachromosomal <span class="hlt">exchanges</span> for low-LET radiation than for high-LET radiation, as has been suggested by others, we argue that the comparison of the prediction of the model with experimental results is not straightforward. With the model, we also show that the probability of the formation of interchromosomal <span class="hlt">exchanges</span> is proportional to the "surface area" of the chromosome domain plus a correction term. The correction term is small if the interaction distance is less than 1 microm for both low- and high-LET radiations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3424243','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3424243"><span id="translatedtitle">LAB-1 Targets PP1 and Restricts Aurora B Kinase upon Entrance into Meiosis to Promote Sister <span class="hlt">Chromatid</span> Cohesion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tzur, Yonatan B.; Egydio de Carvalho, Carlos; Nadarajan, Saravanapriah; Van Bostelen, Ivo; Gu, Yanjie; Chu, Diana S.; Cheeseman, Iain M.; Colaiácovo, Monica P.</p> <p>2012-01-01</p> <p>Successful execution of the meiotic program depends on the timely establishment and removal of sister <span class="hlt">chromatid</span> cohesion. LAB-1 has been proposed to act in the latter by preventing the premature removal of the meiosis-specific cohesin REC-8 at metaphase I in C. elegans, yet the mechanism and scope of LAB-1 function remained unknown. Here we identify an unexpected earlier role for LAB-1 in promoting the establishment of sister <span class="hlt">chromatid</span> cohesion in prophase I. LAB-1 and REC-8 are both required for the chromosomal association of the cohesin complex subunit SMC-3. Depletion of lab-1 results in partial loss of sister <span class="hlt">chromatid</span> cohesion in rec-8 and coh-4 coh-3 mutants and further enhanced <span class="hlt">chromatid</span> dissociation in worms where all three kleisins are mutated. Moreover, lab-1 depletion results in increased Aurora B kinase (AIR-2) signals in early prophase I nuclei, coupled with a parallel decrease in signals for the PP1 homolog, GSP-2. Finally, LAB-1 directly interacts with GSP-1 and GSP-2. We propose that LAB-1 targets the PP1 homologs to the chromatin at the onset of meiosis I, thereby antagonizing AIR-2 and cooperating with the cohesin complex to promote sister <span class="hlt">chromatid</span> association and normal progression of the meiotic program. PMID:22927794</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/14598338','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/14598338"><span id="translatedtitle">Chromosome instability <span class="hlt">induced</span> in vitro with mitomycin C in five Seckel syndrome patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bobabilla-Morales, Lucina; Corona-Rivera, Alfredo; Corona-Rivera, J Román; Buenrostro, C; García-Cobián, Teresa A; Corona-Rivera, Enrique; Cantú-Garza, José María; García-Cruz, Diana</p> <p>2003-12-01</p> <p>Seckel syndrome (SS) is an autosomal recessive entity characterized by proportionate pre- and post-natal growth retardation, microcephaly, typical facial appearance with beak-like protrusion, and severe mental retardation. A heterogeneous basis for SS was proposed since around 25% of SS patients have hematological anomalies, suggesting a subgroup of SS with chromosome instability and hematological disorders. Chromosome instability <span class="hlt">induced</span> by mitomycin C (MMC) has been observed in previous reports. The purpose of this study is to report cytogenetic features in five patients with SS. The patients had low birth weight (mean 1,870 g), short stature (SD = 6.36), microcephaly (OFC, SD = 8.1), typical facial appearance, and multiple articular dislocations. None of them had anemia at the time of examination. In all cases their parents were healthy and non-consanguineous. Lymphocytes of SS patients and a control group (n = 9) matched by age and sex were cultured with and without MMC, and harvested at 72 and 96 hr. Chromosomal aberrations (<span class="hlt">chromatid</span> and chromosomal gaps and breaks, deletions, fragments, and <span class="hlt">exchanges</span>) were scored in 100 metaphases per culture. A statistical increase of chromosomal aberrations was observed in 96 hr MMC cultures in all patients (40.2% vs. 2.8%). Sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> were also performed with no differences between groups. Clinical and cytogenetic findings support the idea that SS may correspond to a chromosome instability syndrome. PMID:14598338</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14598338','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14598338"><span id="translatedtitle">Chromosome instability <span class="hlt">induced</span> in vitro with mitomycin C in five Seckel syndrome patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bobabilla-Morales, Lucina; Corona-Rivera, Alfredo; Corona-Rivera, J Román; Buenrostro, C; García-Cobián, Teresa A; Corona-Rivera, Enrique; Cantú-Garza, José María; García-Cruz, Diana</p> <p>2003-12-01</p> <p>Seckel syndrome (SS) is an autosomal recessive entity characterized by proportionate pre- and post-natal growth retardation, microcephaly, typical facial appearance with beak-like protrusion, and severe mental retardation. A heterogeneous basis for SS was proposed since around 25% of SS patients have hematological anomalies, suggesting a subgroup of SS with chromosome instability and hematological disorders. Chromosome instability <span class="hlt">induced</span> by mitomycin C (MMC) has been observed in previous reports. The purpose of this study is to report cytogenetic features in five patients with SS. The patients had low birth weight (mean 1,870 g), short stature (SD = 6.36), microcephaly (OFC, SD = 8.1), typical facial appearance, and multiple articular dislocations. None of them had anemia at the time of examination. In all cases their parents were healthy and non-consanguineous. Lymphocytes of SS patients and a control group (n = 9) matched by age and sex were cultured with and without MMC, and harvested at 72 and 96 hr. Chromosomal aberrations (<span class="hlt">chromatid</span> and chromosomal gaps and breaks, deletions, fragments, and <span class="hlt">exchanges</span>) were scored in 100 metaphases per culture. A statistical increase of chromosomal aberrations was observed in 96 hr MMC cultures in all patients (40.2% vs. 2.8%). Sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> were also performed with no differences between groups. Clinical and cytogenetic findings support the idea that SS may correspond to a chromosome instability syndrome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677205','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677205"><span id="translatedtitle">Inhibition of NA+/H+ <span class="hlt">Exchanger</span> 1 Attenuates Renal Dysfunction <span class="hlt">Induced</span> by Advanced Glycation End Products in Rats</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Peng; Chen, Geng-Rong; Wang, Fu; Xu, Ping; Liu, Li-Ying; Yin, Ya-Ling; Wang, Shuang-Xi</p> <p>2016-01-01</p> <p>It has been recognized that sodium hydrogen <span class="hlt">exchanger</span> 1 (NHE1) is involved in the development of diabetic nephropathy. The role of NHE1 in kidney dysfunction <span class="hlt">induced</span> by advanced glycation end products (AGEs) remains unknown. Renal damage was <span class="hlt">induced</span> by AGEs via tail vein injections in rats. Function and morphology of kidney were determined. Compared to vehicle- or BSA-treated rats, AGEs caused abnormalities of kidney structures and functions in rats, accompanied with higher MDA level and lower GSH content. Gene expressions of NHE1 gene and TGF-β1 in the renal cortex and urine were also increased in AGEs-injected rats. Importantly, all these detrimental effects <span class="hlt">induced</span> by AGEs were reversed by inhibition of NHE1 or suppression of oxidative stress. These pieces of data demonstrated that AGEs may activate NHE1 to <span class="hlt">induce</span> renal damage, which is related to TGF-β1. PMID:26697498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838874','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838874"><span id="translatedtitle">New mechanism of kinetic <span class="hlt">exchange</span> interaction <span class="hlt">induced</span> by strong magnetic anisotropy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Iwahara, Naoya; Chibotaru, Liviu F.</p> <p>2016-01-01</p> <p>It is well known that the kinetic <span class="hlt">exchange</span> interaction between single-occupied magnetic orbitals (s-s) is always antiferromagnetic, while between single- and double-occupied orbitals (s-d) is always ferromagnetic and much weaker. Here we show that the <span class="hlt">exchange</span> interaction between strongly anisotropic doublets of lanthanides, actinides and transition metal ions with unquenched orbital momentum contains a new s-d kinetic contribution equal in strength with the s-s one. In non-collinear magnetic systems, this s-d kinetic mechanism can cause an overall ferromagnetic <span class="hlt">exchange</span> interaction which can become very strong for transition metal ions. These findings are fully confirmed by DFT based analysis of <span class="hlt">exchange</span> interaction in several Ln3+ complexes. PMID:27098292</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4472013','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4472013"><span id="translatedtitle"><span class="hlt">Chromatids</span> segregate without centrosomes during Caenorhabditis elegans mitosis in a Ran- and CLASP-dependent manner</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nahaboo, Wallis; Zouak, Melissa; Askjaer, Peter; Delattre, Marie</p> <p>2015-01-01</p> <p>During mitosis, chromosomes are connected to a microtubule-based spindle. Current models propose that displacement of the spindle poles and/or the activity of kinetochore microtubules generate mechanical forces that segregate sister <span class="hlt">chromatids</span>. Using laser destruction of the centrosomes during Caenorhabditis elegans mitosis, we show that neither of these mechanisms is necessary to achieve proper <span class="hlt">chromatid</span> segregation. Our results strongly suggest that an outward force generated by the spindle midzone, independently of centrosomes, is sufficient to segregate chromosomes in mitotic cells. Using mutant and RNAi analysis, we show that the microtubule-bundling protein SPD-1/MAP-65 and BMK-1/kinesin-5 act as a brake opposing the force generated by the spindle midzone. Conversely, we identify a novel role for two microtubule-growth and nucleation agents, Ran and CLASP, in the establishment of the centrosome-independent force during anaphase. Their involvement raises the interesting possibility that microtubule polymerization of midzone microtubules is continuously required to sustain chromosome segregation during mitosis. PMID:25833711</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25833711','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25833711"><span id="translatedtitle"><span class="hlt">Chromatids</span> segregate without centrosomes during Caenorhabditis elegans mitosis in a Ran- and CLASP-dependent manner.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nahaboo, Wallis; Zouak, Melissa; Askjaer, Peter; Delattre, Marie</p> <p>2015-06-01</p> <p>During mitosis, chromosomes are connected to a microtubule-based spindle. Current models propose that displacement of the spindle poles and/or the activity of kinetochore microtubules generate mechanical forces that segregate sister <span class="hlt">chromatids</span>. Using laser destruction of the centrosomes during Caenorhabditis elegans mitosis, we show that neither of these mechanisms is necessary to achieve proper <span class="hlt">chromatid</span> segregation. Our results strongly suggest that an outward force generated by the spindle midzone, independently of centrosomes, is sufficient to segregate chromosomes in mitotic cells. Using mutant and RNAi analysis, we show that the microtubule-bundling protein SPD-1/MAP-65 and BMK-1/kinesin-5 act as a brake opposing the force generated by the spindle midzone. Conversely, we identify a novel role for two microtubule-growth and nucleation agents, Ran and CLASP, in the establishment of the centrosome-independent force during anaphase. Their involvement raises the interesting possibility that microtubule polymerization of midzone microtubules is continuously required to sustain chromosome segregation during mitosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/88800','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/88800"><span id="translatedtitle">The influence of internally deposited alpha ({sup 239}Pu) or beta-gamma ({sup 144}Ce) emitting radionuclides on the sensitivity of Chinese hamster bone marrow cells to {sup 60}CO <span class="hlt">induced</span> chromosome aberrations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brooks, A.L.; McDonald, K.E.; Kitchin, R.M.</p> <p>1994-12-31</p> <p>The current study was designed to determine if protracted low-dose-rate exposures from either high-({sup 239}Pu) or low-({sup 144}Ce) LET radiation from internally deposited radioactive materials changes the frequency of chromosome aberrations <span class="hlt">induced</span> by acute {sup 60}Co exposure. THe potential for interaction was evaluated 30 days after injection with either 0 or 0.85 kBq {sup 144}Ce g{sup -1} body weight or 0.0 or 2.2 Bq of {sup 239}Pu g{sup -1}. Injection with {sup 239}Pu or {sup 144}Ce resulted in few aberrations in bone marrow cells 30 days after injection. The presence of internally deposited {sup 239}Pu or {sup 144}Ce did not significantly alter the total frequency of {sup 60}Co <span class="hlt">induced</span> aberrations. However, the frequency of {sup 60}Co <span class="hlt">induced</span> <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> was significantly greater (P=0.03) in bone marrow cells of animals with {sup 144}Ce body burdens (0.14{+-}0.03 <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>/cell). Such data illustrates that changes in cellular responsiveness may be dependent on the LET of the isotope, the dose rate of the primary dose and the type of damage being evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080632','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080632"><span id="translatedtitle">Water-<span class="hlt">Induced</span> Decoupling of Tracer and Electrochemical Oxygen <span class="hlt">Exchange</span> Kinetics on Mixed Conducting Electrodes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>Isotope <span class="hlt">exchange</span> depth profiling and electrochemical impedance spectroscopy are usually regarded as complementary tools for measuring the surface oxygen <span class="hlt">exchange</span> activity of mixed conducting oxides, for example used in solid oxide fuel cell (SOFC) electrodes. Only very few studies compared electrical (kq) and tracer (k*) <span class="hlt">exchange</span> coefficients of solid–gas interfaces measured under identical conditions. The 1:1 correlation between kq and k* often made is thus more an assumption than experimentally verified. In this study it is shown that the measured rates of electrical and tracer <span class="hlt">exchange</span> of oxygen may strongly differ. Simultaneous acquisition of kq and k* on La0.6Sr0.4FeO3-δ and SrTi0.3Fe0.7O3-δ thin film electrodes revealed that k* > 100 kq in humid oxidizing (16O2 + H218O) and humid reducing (H2 + H218O) atmospheres. These results are explained by fast water adsorption and dissociation on surface oxygen vacancies, forming two surface hydroxyl groups. Hence, interpreting experimentally determined k* values in terms of electrochemically relevant oxygen <span class="hlt">exchange</span> is not straightforward. PMID:27389420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27389420','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27389420"><span id="translatedtitle">Water-<span class="hlt">Induced</span> Decoupling of Tracer and Electrochemical Oxygen <span class="hlt">Exchange</span> Kinetics on Mixed Conducting Electrodes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nenning, Andreas; Navickas, Edvinas; Hutter, Herbert; Fleig, Jürgen</p> <p>2016-07-21</p> <p>Isotope <span class="hlt">exchange</span> depth profiling and electrochemical impedance spectroscopy are usually regarded as complementary tools for measuring the surface oxygen <span class="hlt">exchange</span> activity of mixed conducting oxides, for example used in solid oxide fuel cell (SOFC) electrodes. Only very few studies compared electrical (k(q)) and tracer (k*) <span class="hlt">exchange</span> coefficients of solid-gas interfaces measured under identical conditions. The 1:1 correlation between k(q) and k* often made is thus more an assumption than experimentally verified. In this study it is shown that the measured rates of electrical and tracer <span class="hlt">exchange</span> of oxygen may strongly differ. Simultaneous acquisition of k(q) and k* on La0.6Sr0.4FeO3-δ and SrTi0.3Fe0.7O3-δ thin film electrodes revealed that k* > 100 k(q) in humid oxidizing ((16)O2 + H2(18)O) and humid reducing (H2 + H2(18)O) atmospheres. These results are explained by fast water adsorption and dissociation on surface oxygen vacancies, forming two surface hydroxyl groups. Hence, interpreting experimentally determined k* values in terms of electrochemically relevant oxygen <span class="hlt">exchange</span> is not straightforward. PMID:27389420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25815963','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25815963"><span id="translatedtitle">Electric-field-<span class="hlt">induced</span> modification of the magnon energy, <span class="hlt">exchange</span> interaction, and curie temperature of transition-metal thin films.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oba, M; Nakamura, K; Akiyama, T; Ito, T; Weinert, M; Freeman, A J</p> <p>2015-03-13</p> <p>The electric-field-<span class="hlt">induced</span> modification in the Curie temperature of prototypical transition-metal thin films with the perpendicular magnetic easy axis, a freestanding Fe(001) monolayer and a Co monolayer on Pt(111), is investigated by first-principles calculations of spin-spiral structures in an external electric field (E field). An applied E field is found to modify the magnon (spin-spiral formation) energy; the change arises from the E-field-<span class="hlt">induced</span> screening charge density in the spin-spiral states due to p-d hybridizations. The Heisenberg <span class="hlt">exchange</span> parameters obtained from the magnon energy suggest an E-field-<span class="hlt">induced</span> modification of the Curie temperature, which is demonstrated via Monte Carlo simulations that take the magnetocrystalline anisotropy into account.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhD...48A5002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhD...48A5002W"><span id="translatedtitle">Temperature dependence of <span class="hlt">exchange</span> bias and training effect in Co/CoO film with <span class="hlt">induced</span> uniaxial anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, R.; Fu, J. B.; Zhou, D.; Ding, S. L.; Wei, J. Z.; Zhang, Y.; Du, H. L.; Wang, C. S.; Yang, Y. C.; Yang, J. B.</p> <p>2015-06-01</p> <p>The <span class="hlt">exchange</span> bias effect and training effect of the Co/CoO film with <span class="hlt">induced</span> uniaxial anisotropy were investigated as functions of temperature. It was found that both effects exhibited drastic differences along the easy and the hard axes. Along the easy axis, the magnetization reversal was dominated by domain wall motion throughout the whole temperature range. However, along the hard axis, the magnetization reversal was dominated by domain wall motion and domain rotation at temperatures below and above 150 K, respectively. The crossover of the two reversal modes characterized with significant asymmetry in the hysteresis loop was observed along the hard axis at 150 K due to the interplay between the <span class="hlt">exchange</span> and uniaxial anisotropies. Significant difference of training effect in the two directions was observed and ascribed to the differences of the duration and intensity of the interaction between ferromagnetic and antiferromagnetic spins in the two magnetization reversal modes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19071590','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19071590"><span id="translatedtitle">Determination of glyphosate using off-line ion <span class="hlt">exchange</span> preconcentration and capillary electrophoresis-laser <span class="hlt">induced</span> fluorescence detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiang, Jiang; Lucy, Charles A</p> <p>2007-04-15</p> <p>An enrichment method for the herbicide glyphosate is presented based on ion <span class="hlt">exchange</span> solid phase extraction (SPE) technique. A 200-mul micro-pipette tip packed with 50mg of Bio-Rad AG1-X8 anion <span class="hlt">exchanger</span> beads was used for offline extraction of glyphosate from 50ml of spiked river water sample. The retained glyphosate was eluted with 10mM HCl and then converted quantitatively to the corresponding amine (glycine) using hypochlorite. Subsequent fluorescent labeling using naphthalene-2,3-dicarboxaldehyde (NDA)-cyanide allowed micellar electrokinetic chromatography (MEKC) separation and laser-<span class="hlt">induced</span> fluorescence detection (LIF) with a violet diode laser. Optimization of the sample clean-up, extraction, elution, conversion and labeling steps enabled analysis of glyphosate in river water in the nanomolar range. Detection limits were 0.04nM glyphosate in standards and 1.6nM in spiked river.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JIEx...21...29S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JIEx...21...29S"><span id="translatedtitle">Preparation of Cation-<span class="hlt">Exchange</span> Particle Designed for High-Speed Collection of Proteins by Radiation-<span class="hlt">Induced</span> Graft Polymerization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sekiya, Yuta; Shimoda, Yuichi; Umeno, Daisuke; Saito, Kyoichi; Furumoto, Goro; Shirataki, Hironobu; Shinohara, Naoyuki; Kubota, Noboru</p> <p></p> <p>A cation-<span class="hlt">exchange</span> polymer brush was immobilized onto a polyethylene-based particle with an average diameter of 35 μm by radiation-<span class="hlt">induced</span> graft polymerization of glycidyl methacrylate and subsequent sulfonation with sodium sulfite. A lysozyme solution was forced to flow through a bed (height 2 cm, cross-sectional area 0.61 cm2) charged with the resultant cation-<span class="hlt">exchange</span> particles at a space velocity ranging from 500 to 2300 h-1. From a viewpoint of equilibrium binding capacity and elution percentage of lysozyme, the dose of electron beam and the degree of GMA grafting were optimized to be 200 kGy and 100%, respectively. The bed exhibited a constant dynamic binding capacity of lysozyme 14 mg⁄mL irrespective of space velocity due to negligible diffusional mass-transfer resistance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.108s2402L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.108s2402L"><span id="translatedtitle"><span class="hlt">Exchange</span> magnon <span class="hlt">induced</span> resistance asymmetry in permalloy spin-Hall oscillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langenfeld, S.; Tshitoyan, V.; Fang, Z.; Wells, A.; Moore, T. A.; Ferguson, A. J.</p> <p>2016-05-01</p> <p>We investigate magnetization dynamics in a spin-Hall oscillator using a direct current measurement as well as conventional microwave spectrum analysis. When the current applies an anti-damping spin-transfer torque, we observe a change in resistance which we ascribe mainly to the excitation of incoherent <span class="hlt">exchange</span> magnons. A simple model is developed based on the reduction of the effective saturation magnetization, quantitatively explaining the data. The observed phenomena highlight the importance of <span class="hlt">exchange</span> magnons on the operation of spin-Hall oscillators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25378216','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25378216"><span id="translatedtitle">Oxygen-<span class="hlt">induced</span> plasticity in tracheal morphology and discontinuous gas <span class="hlt">exchange</span> cycles in cockroaches Nauphoeta cinerea.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartrim, Hamish; Matthews, Philip G D; Lemon, Sussan; White, Craig R</p> <p>2014-12-01</p> <p>The function and mechanism underlying discontinuous gas <span class="hlt">exchange</span> in terrestrial arthropods continues to be debated. Three adaptive hypotheses have been proposed to explain the evolutionary origin or maintenance of discontinuous gas <span class="hlt">exchange</span> cycles (DGCs), which may have evolved to reduce respiratory water loss, facilitate gas <span class="hlt">exchange</span> in high CO2 and low O2 micro-environments, or to ameliorate potential damage as a result of oversupply of O2. None of these hypotheses have unequivocal support, and several non-adaptive hypotheses have also been proposed. In the present study, we reared cockroaches Nauphoeta cinerea in selected levels of O2 throughout development, and examined how this affected growth rate, tracheal morphology and patterns of gas <span class="hlt">exchange</span>. O2 level in the rearing environment caused significant changes in tracheal morphology and the exhibition of DGCs, but the direction of these effects was inconsistent with all three adaptive hypotheses: water loss was not associated with DGC length, cockroaches grew fastest in hyperoxia, and DGCs exhibited by cockroaches reared in normoxia were shorter than those exhibited by cockroaches reared in hypoxia or hyperoxia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2228876','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2228876"><span id="translatedtitle">Intracellular acidification-<span class="hlt">induced</span> alkali metal cation/H+ <span class="hlt">exchange</span> in human neutrophils</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>1987-01-01</p> <p>Pretreatment of isolated human neutrophils (resting pHi congruent to 7.25 at pHo 7.40) with 30 mM NH4Cl for 30 min leads to an intracellular acidification (pHi congruen to 6.60) when the NH4Cl prepulse is removed. Thereafter, in 140 mM Na+ medium, pHi recovers exponentially with time (initial rate, approximately 0.12 pH/min) to reach the normal resting pHi by approximately 20 min, a process that is accomplished mainly, if not exclusively, though an <span class="hlt">exchange</span> of internal H+ for external Na+. This Na+/H+ countertransport is stimulated by external Na+ (Km congruent to 21 mM) and by external Li+ (Km congruent to 14 mM), though the maximal transport rate for Na+ is about twice that for Li+. Both Na+ and Li+ compete as substrates for the same translocation sites on the <span class="hlt">exchange</span> carrier. Other alkali metal cations, such as K+, Rb+, or Cs+, do not promote pHi recovery, owing to an apparent lack of affinity for the carrier. The <span class="hlt">exchange</span> system is unaffected by ouabain or furosemide, but can be competitively inhibited by the diuretic amiloride (Ki congruent to 8 microM). The influx of Na+ or Li+ is accompanied by an equivalent counter-reflux of H+, indicating a 1:1 stoichiometry for the <span class="hlt">exchange</span> reaction, a finding consistent with the lack of voltage sensitivity (i.e., electroneutrality) of pHi recovery. These studies indicate that the predominant mechanism in human neutrophils for pHi regulation after intracellular acidification is an amiloride-sensitive alkali metal cation/H+ <span class="hlt">exchange</span> that shares a number of important features with similar recovery processes in a variety of other mammalian cell types. PMID:3694176</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510348S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510348S"><span id="translatedtitle">Light-<span class="hlt">induced</span> diurnal pattern of methane <span class="hlt">exchange</span> in a boreal forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sundqvist, Elin; Crill, Patrick; Mölder, Meelis; Vestin, Patrik; Lindroth, Anders</p> <p>2013-04-01</p> <p>Boreal forests represents one third of the Earth's forested land surface area and is a net sink of methane and an important component of the atmospheric methane budget. Methane is oxidized in well-aerated forest soils whereas ponds and bog soils are sources of methane. Besides the microbial processes in the soil also forest vegetation might contribute to methane <span class="hlt">exchange</span>. Due to a recent finding of methane consumption by boreal plants that correlated with photosynthetic active radiation (PAR), we investigate the impact of PAR on soil methane <span class="hlt">exchange</span> at vegetated plots on the forest floor. The study site, Norunda in central Sweden, is a 120 years old boreal forest stand, dominated by Scots pine and Norway spruce. We used continuous chamber measurements in combination with a high precision laser gas analyzer (Los Gatos Research), to measure the methane <span class="hlt">exchange</span> at four different plots in July-November 2009, and April-June 2010. The ground vegetation consisted almost entirely of mosses and blueberry-shrubs. Two of the plots acted as stable sinks of methane whereas the other two plots shifted from sinks to sources during very wet periods. The preliminary results show a clear diurnal pattern of the methane <span class="hlt">exchange</span> during the growing season, which cannot be explained by temperature. The highest consumption occurs at high PAR levels. The amplitude of the diurnal methane <span class="hlt">exchange</span> during the growing season is in the order of 10 μmol m-2 h-1. This indicates that besides methane oxidation by methanotrophs in the soil there is an additional removal of methane at soil level by a process related to ground vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467855','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467855"><span id="translatedtitle">Phosphorylation of the <span class="hlt">exchange</span> factor DENND3 by ULK in response to starvation activates Rab12 and <span class="hlt">induces</span> autophagy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Jie; Fotouhi, Maryam; McPherson, Peter S</p> <p>2015-01-01</p> <p>Unc-51-like kinases (ULKs) are the most upstream kinases in the initiation of autophagy, yet the molecular mechanisms underlying their function are poorly understood. We report a new role for ULK in the induction of autophagy. ULK-mediated phosphorylation of the guanine nucleotide <span class="hlt">exchange</span> factor DENND3 at serines 554 and 572 upregulates its GEF activity toward the small GTPase Rab12. Through binding to LC3 and associating with LC3-positive autophagosomes, active Rab12 facilitates autophagosome trafficking, thus establishing a crucial role for the ULK/DENND3/Rab12 axis in starvation-<span class="hlt">induced</span> autophagy. PMID:25925668</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20991421','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20991421"><span id="translatedtitle">Elimination of radiation-<span class="hlt">induced</span> {gamma}-H2AX foci in mammalian nucleus can occur by histone <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Svetlova, Maria; Solovjeva, Liudmila; Nishi, Kayoko; Nazarov, Igor; Siino, Joseph; Tomilin, Nikolai . E-mail: nvtom@mail.ru</p> <p>2007-06-29</p> <p>Double-strand breaks in mammalian DNA lead to rapid phosphorylation of C-terminal serines in histone H2AX ({gamma}-H2AX) and formation of large nuclear {gamma}-H2AX foci. After DNA repair these foci disappear, but molecular mechanism of elimination of {gamma}-H2AX foci remains unclear. H2AX protein can be phosphorylated and dephosphorylated in vitro in the absence of chromatin. Here, we compared global <span class="hlt">exchange</span> of GFP-H2AX with kinetics of formation and elimination of radiation-<span class="hlt">induced</span> {gamma}-H2AX foci. Maximal number of {gamma}-H2AX foci is observed one hour after irradiation, when {approx}20% of GFP-H2AX is <span class="hlt">exchanged</span> suggesting that formation of the foci mostly occurs by in situ H2AX phosphorylation. However, slow elimination of {gamma}-H2AX foci is weakly affected by an inhibitor of protein phosphatases calyculin A which is known as an agent suppressing dephosphorylation of {gamma}-H2AX. This indicates that elimination of {gamma}-H2AX foci may be independent of dephosphorylation of H2AX which can occur after its removal from the foci by <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26643143','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26643143"><span id="translatedtitle">PICH promotes sister <span class="hlt">chromatid</span> disjunction and co-operates with topoisomerase II in mitosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nielsen, Christian F; Huttner, Diana; Bizard, Anna H; Hirano, Seiki; Li, Tian-Neng; Palmai-Pallag, Timea; Bjerregaard, Victoria A; Liu, Ying; Nigg, Erich A; Wang, Lily Hui-Ching; Hickson, Ian D</p> <p>2015-12-08</p> <p>PICH is a SNF2 family DNA translocase that binds to ultra-fine DNA bridges (UFBs) in mitosis. Numerous roles for PICH have been proposed from protein depletion experiments, but a consensus has failed to emerge. Here, we report that deletion of PICH in avian cells causes chromosome structural abnormalities, and hypersensitivity to an inhibitor of Topoisomerase II (Topo II), ICRF-193. ICRF-193-treated PICH(-/-) cells undergo sister <span class="hlt">chromatid</span> non-disjunction in anaphase, and frequently abort cytokinesis. PICH co-localizes with Topo IIα on UFBs and at the ribosomal DNA locus, and the timely resolution of both structures depends on the ATPase activity of PICH. Purified PICH protein strongly stimulates the catalytic activity of Topo II in vitro. Consistent with this, a human PICH(-/-) cell line exhibits chromosome instability and chromosome condensation and decatenation defects similar to those of ICRF-193-treated cells. We propose that PICH and Topo II cooperate to prevent chromosome missegregation events in mitosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21518475','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21518475"><span id="translatedtitle">Anisotropy <span class="hlt">induced</span> large <span class="hlt">exchange</span> bias behavior in ball milled Ni-Co-Mn-Sb alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nayak, Ajaya K.; Sahoo, Roshnee; Suresh, K. G.; Nigam, A. K.; Chen, X.; Ramanujan, R. V.</p> <p>2011-06-06</p> <p>We report the effect of decrease in the grain size on the structural, magnetic and <span class="hlt">exchange</span> bias (EB) behavior in ball milled Ni{sub 50-x}Co{sub x}Mn{sub 38}Sb{sub 12} (x=0 and 5) Heusler alloys. The existence of a wide range of grain sizes in the ball milled samples results in dramatic changes in the structural and magnetic properties. For x=0, a large EB field of 3.2 kOe is observed in the ball milled sample, compared to a value of 245 Oe of the bulk sample. This increase is attributed to the enhanced <span class="hlt">exchange</span> coupling between the soft and hard magnetic particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1980imvc.rept.....P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1980imvc.rept.....P&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Induced</span> magnetism via conduction electron <span class="hlt">exchange</span>: Application to PrAl sub 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palermo, L.; Dasilva, X. A.</p> <p>1980-07-01</p> <p>The magnetization, susceptibility and magnetic specific heat of PrAl2 versus temperature are studied within a model where the onset of magnetism is due to mutual magnetization of the rare-earth ions and the conduction electrons, the ionic magnetization process being ban Bleck-like. The crystal field, bandwith and <span class="hlt">exchange</span> parameters of the model which fit the available experimental data are 2.5 meV, 7000 meV and 341 meV, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1207794','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1207794"><span id="translatedtitle">Mobilization of a Minos Transposon in Drosophila Melanogaster Chromosomes and <span class="hlt">Chromatid</span> Repair by Heteroduplex Formation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Arca, B.; Zabalou, S.; Loukeris, T. G.; Savakis, C.</p> <p>1997-01-01</p> <p>Transposase-mediated mobilization of the element Minos has been studied in the Drosophila melanogaster genome. Excision and transposition of a nonautonomous Minos transposon in the presence of a Minos transposase gene was detected with a dominant eye color marker carried by the transposon. Frequencies of excision in somatic tissues and in the germ line were higher in flies heterozygous for the transposon than in homozygotes or hemizygotes. Transposition of a X chromosome-linked insertion of Minos into new autosomal sites occurred in 1-12% of males expressing transposase, suggesting that this system is usable for gene tagging and enhancer trapping in Drosophila. Sequence analysis of PCR-amplified donor sites after excision showed precise restoration of the original target sequence in ~75% of events in heterozygotes and the presence of footprints or partially deleted elements in the remaining events. Most footprints consisted of the four terminal bases of the transposon, flanked by the TA target duplication. Sequencing of a chromosomal donor site that was directly cloned after excision showed a characteristic two-base mismatch heteroduplex in the center of the 6-bp footprint. Circular extrachromosomal forms of the transposon, presumably representing excised Minos elements, could be detected only in the presence of transposase. A model for <span class="hlt">chromatid</span> repair after Minos excision is discussed in which staggered cuts are first produced at the ends of the inverted repeats, the broken <span class="hlt">chromatid</span> ends are joined, and the resulting heteroduplex is subsequently repaired. The model also suggests a simple mechanism for the production of the target site duplication and for regeneration of the transposon ends during reintegration. PMID:9071583</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=Breaks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBreaks','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=Breaks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBreaks"><span id="translatedtitle">Distributions of Low- and High-LET Radiation-<span class="hlt">Induced</span> Breaks in Chromosomes are Associated with Inter- and Intrachromosome <span class="hlt">Exchanges</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hada, Megumi; Zhang, Ye; Feiveson, Alan; Cucinotta, Francis A.; Wu, Honglu</p> <p>2010-01-01</p> <p>To study the breakpoint along the length of the chromosome <span class="hlt">induced</span> by low- and high-LET radiations, we exposed human epithelial cells in vitro to Cs-137 rays at both low and high dose rates, secondary neutrons at a low dose rate, and 600 MeV/u Fe ions at a high dose rate. The location of the breaks was identified using the multicolor banding in situ hybridization (mBAND) that paints Chromosome 3 in 23 different colored bands. The breakpoint distributions were found to be similar between rays of low and high dose rates and between the two high-LET radiation types. Detailed analysis of the chromosome break ends involved in inter- and intrachromosome <span class="hlt">exchanges</span> revealed that only the break ends participating in interchromosome <span class="hlt">exchanges</span> contributed to the hot spots found for low-LET. For break ends participating in intrachromosome <span class="hlt">exchanges</span>, the distributions for all four radiation scenarios were similar with clusters of breaks found in three regions. Analysis of the locations of the two break ends in Chromosome 3 that joined to form an intrachromosome <span class="hlt">exchange</span> demonstrated that two breaks with a greater genomic separation may be more likely to rejoin than two closer breaks, indicating that chromatin folding can play an important role in the rejoining of chromosome breaks. Our study demonstrated that the gene-rich regions do not necessarily contain more breaks. The breakpoint distribution depends more on the likelihood that a break will join with another break in the same chromosome or in a different chromosome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.2266Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.2266Z"><span id="translatedtitle">Correlation Between Interphase Chromatin Structure and - and High-Let Radiation-<span class="hlt">Induced</span> - and Intra-Chromosome <span class="hlt">Exchange</span> Hotspots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ye; Wu, Honglu; Mangala, Lingegowda; Asaithamby, Aroumougame; Chen, David</p> <p>2012-07-01</p> <p>CORRELATION BETWEEN INTERPHASE CHROMATIN STRUCTURE AND LOW- AND HIGH-LET RADIATION-<span class="hlt">INDUCED</span> INTER- AND INTRA-CHROMOSOME <span class="hlt">EXCHANGE</span> HOTSPOTS Ye Zhang1,2, Lingegowda S. Mangala1,3, Aroumougame Asaithamby4, David J. Chen4, and Honglu Wu1 1 NASA Johnson Space Center, Houston, Texas, USA 2 Wyle Integrated Science and Engineering Group, Houston, Texas, USA 3 University of Houston Clear Lake, Houston, Texas, USA 4 University of Texas, Southwestern Medical Center, Dallas, Texas, USA To investigate the relationship between chromosome aberrations <span class="hlt">induced</span> by low- and high-LET radiation and chromatin folding, we reconstructed the three dimensional structure of chromosome 3 and measured the physical distances between different regions of this chromosome. Previously, we investigated the location of breaks involved in inter- and intrachromosomal type <span class="hlt">exchange</span> events in chromosome 3 of human epithelial cells, using the multicolor banding in situ hybridization (mBAND) technique. After exposure to both low- and high-LET radiations in vitro, intra-chromosome <span class="hlt">exchanges</span> occurred preferentially between a break in the 3p21 and one in the 3q11 regions, and the breaks involved in inter-chromosome <span class="hlt">exchanges</span> occurred in two regions near the telomeres of the chromosome. In this study, human epithelial cells were fixed in G1 phase and interphase chromosomes hybridized with an mBAND probe for chromosome 3 were captured with a laser scanning confocal microscope. The 3-dimensional structure of interphase chromosome 3 with different colored regions was reconstructed, and the distance between different regions was measured. We show that, in most of the G1 cells, the regions containing 3p21 and 3q11 are colocalized in the center of the chromosome domain, whereas, the regions towards the telomeres of the chromosome are located in the peripherals of the chromosome domain. Our results demonstrate that the distribution of breaks involved in radiation-<span class="hlt">induced</span> inter and intra-chromosome aberrations depends</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014WRR....50.4643M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.4643M"><span id="translatedtitle">Hydraulic and thermal effects of in-stream structure-<span class="hlt">induced</span> hyporheic <span class="hlt">exchange</span> across a range of hydraulic conductivities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menichino, Garrett T.; Hester, Erich T.</p> <p>2014-06-01</p> <p>In-stream structure-<span class="hlt">induced</span> hyporheic <span class="hlt">exchange</span> and associated thermal dynamics affect stream ecosystems. Their importance is controlled by spatial variability of sediment hydraulic conductivity (K). We calibrated a computational fluid dynamics (CFD) model of surface and groundwater hydraulics near a channel-spanning weir (represents log dams, boulder weirs) to field data and varied K from 10-7 to 10-2 m/s (silt to gravel). Surface water stopped cresting the weir for K > 10-3 m/s. Non-Darcy hyporheic flow was also prevalent for K > 10-3 m/s, and velocity errors using non-CFD models ranged up to 32.2%. We also modeled weir-<span class="hlt">induced</span> heat transport during summer. As K increased from 10-7 to 10-3 m/s, weir-<span class="hlt">induced</span> hyporheic heat advection steadily increased. Cooling and buffering along hyporheic flow paths decreased with increasing K, particularly above K = 10-5 and 10-4 m/s, respectively. Vertical heat conduction between surface water and groundwater near the weir decreased with increasing K, particularly for K > 10-5 m/s. Conduction between hyporheic flow paths and adjacent groundwater helped cool hyporheic flow. Downstream surface water cooling by hyporheic advection increased steadily with K as increases in hyporheic flow overwhelmed decreases in cooling along hyporheic flow paths. Yet such effects were small (0.016°C) even at K = 10-3 m/s. The largest thermal effect of weir-<span class="hlt">induced</span> <span class="hlt">exchange</span> was therefore spatial expansion of subsurface diel variability (particularly for K > 10-5 m/s) which affects benthic habitat and chemical reactions. The specific values of K where such trend shifts occur is likely variable among streams based on flow conditions, but we expect the presence of such trend shifts to be widespread.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24582716','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24582716"><span id="translatedtitle">Macrophage alteration <span class="hlt">induced</span> by inflammatory toxins isolated from Tityus discrepans scorpion venom. The role of Na(+)/Ca(2+) <span class="hlt">exchangers</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramírez-Bello, Vanesa; Sevcik, Carlos; Peigneur, Steve; Tytgat, Jan; D'Suze, Gina</p> <p>2014-05-01</p> <p>We study the effect of all Tityus discrepans venom components on macrophage alterations. Only seven toxins called "Inflammatory Toxin" (InfTx1-7) <span class="hlt">induced</span> cell changes. Incubation with InfTx1 through InfTx5 rose macrophage NO level at 2 h toxin exposure. Cells rose NO release by 4 h exposure with InfTx2 and InfTx5, the NO levels reached concentrations similar or higher than the <span class="hlt">induced</span> by lipopolysaccharides (LPS) incubation. InfTx2, -6 and -7 increased cell TNF-α release. InfTx2 as LPS roses cell TNF-α secretion gradually in time. Macrophages were loaded with fluorescent dyes, exposed to all toxins and observed with a 3D wide field deconvolution setup. Cells exposed to whole venom or InfTx4 through InfTx7 developed pseudopodia, cytoplasm prolongations, blebs, and loss their rounded form. The molecular masses and N-terminal sequences of InfTx4 through InfTx7 were analyzed by MALDI-TOF mass spectrometry and Edman degradation. InfTx4-7 <span class="hlt">induced</span> a remarkable increase of intracellular Ca(2+) levels ([Ca(2+)]i), measured as a rise of normalized cell green fluorescence intensity (FI) ×2.7, ×2.6, ×95 and ×2.9 the controls, respectively. InfTx6-7 action mechanisms were studied under different conditions. Results suggested that InfTx6 interact with a membrane sodium channel <span class="hlt">inducing</span> cell depolarization with a consequent increase on intracellular [Na(+)], this would activate Na(+)/Ca(2+) <span class="hlt">exchanger</span> 3 (NCX) in the reverse mode and the phospholipase C inositol 1,4,5-trisphosphate (PLC-IP3) signaling pathway <span class="hlt">inducing</span> [Ca(2+)]i overload. Inftx7 should activate the NCX in reverse mode and/or should activate the Na(+)/H(+) <span class="hlt">exchanger</span>, increasing intracellular [Na(+)] which indirectly <span class="hlt">induce</span> the activation of NCX3rv and the PLC-IP3 signaling pathway. All these mechanisms would cooperate with the [Ca(2+)]i overload. A rise of [Ca(2+)]i activates the synthesis and secretion of inflammatory molecules like TNF-α, which in turn, increases the gene transcription for <span class="hlt">inducible</span> nitric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267994','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267994"><span id="translatedtitle">Involvement of the Sodium-Calcium <span class="hlt">exchanger</span> 3 (NCX3) in ziram-<span class="hlt">induced</span> calcium dysregulation and toxicity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jin, J.; Lao, A.J.; Katsura, M.; Caputo, A.; Schweizer, F. E.; Sokolow, S.</p> <p>2014-01-01</p> <p>Ziram is a dimethyldithiocarbamate fungicide which can cause intraneuronal calcium (Ca2+) dysregulation and subsequently neuronal death. The signaling mechanisms underlying ziram-<span class="hlt">induced</span> Ca2+ dyshomeostasis and neurotoxicity are not fully understood. NCX3 is the third isoform of the sodium-calcium <span class="hlt">exchanger</span> (NCX) family and plays an important role in regulating Ca2+ homeostasis in excitable cells. We previously generated a mouse model deficient for the sodium-calcium <span class="hlt">exchanger</span> 3 and showed that NCX3 is protective against ischemic damage. In the present study, we aim to examine whether NCX3 exerts a similar role against toxicological injury caused by the pesticide ziram. Our data show baby hamster kidney (BHK) cells stably transfected with NCX3 (BHK-NCX3) are more susceptible to ziram toxicity than cells transfected with the empty vector (BHK-WT). Increased toxicity in BHK-NCX3 was associated with a rapid rise in cytosolic Ca2+ concentration [Ca2+i] <span class="hlt">induced</span> by ziram. Profound mitochondrial dysfunction and ATP depletion were also observed in BHK-NCX3 cells following treatment with ziram. Lastly, primary dopaminergic neurons lacking NCX3 (NCX3−/−) were less sensitive to ziram neurotoxicity than wildtype control dopaminergic neurons. These results demonstrate that NCX3 genetic deletion protects against ziram-<span class="hlt">induced</span> neurotoxicity and suggest NCX3 and its downstream molecular pathways as key factors involved in ziram toxicity. Our study identifies new molecular events through which pesticides (e.g. ziram) can lead to pathological features of degenerative diseases such as Parkinson’s disease and indicates new targets to slow down neuronal degeneration. PMID:25284465</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995NIMPB..96..382C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995NIMPB..96..382C&link_type=ABSTRACT"><span id="translatedtitle">Irradiation-<span class="hlt">induced</span> Ag-colloid formation in ion-<span class="hlt">exchanged</span> soda-lime glass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caccavale, F.; De Marchi, G.; Gonella, F.; Mazzoldi, P.; Meneghini, C.; Quaranta, A.; Arnold, G. W.; Battaglin, G.; Mattei, G.</p> <p>1995-03-01</p> <p>Ion-<span class="hlt">exchanged</span> glass samples were obtained by immersing soda-lime slides in molten salt baths of molar concentration in the range 1-20% AgNO 3 in NaNO 3, at temperatures varying from 320 to 350°C, and processing times of the order of a few minutes. Irradiations of <span class="hlt">exchanged</span> samples were subsequently performed by using H +m, He +, N + ions at different energies in order to obtain comparable projected ranges. The fluence was varied between 5 × 10 15 and 2 × 10 17 ions/cm 2. Most of the samples were treated at current densities lower than 2 μA/cm 2, in order to avoid heating effects. Some samples were irradiated with 4 keV electrons, corresponding to a range of 250 nm. The formation of nanoclusters of radii in the range 1-10 nm has been observed after irradiation, depending on the treatment conditions. The precipitation process is governed by the electronic energy deposition of incident particles. The most desirable results are obtained for helium implants. The process was characterized by the use of Secondary Ion Mass Spectrometry (SIMS) and nuclear techniques (Rutherford Backscattering (RBS), Nuclear Reactions (NRA)), in order to determine concentration-depth profiles and by optical absorption and Transmission Electron Microscopy (TEM) measurements for the silver nanoclusters detection and size evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93i4411A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93i4411A"><span id="translatedtitle"><span class="hlt">Exchange</span> bias caused by field-<span class="hlt">induced</span> spin reconfiguration in Ni-Mn-Sn</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>ćakır, A.; Acet, M.; Farle, M.</p> <p>2016-03-01</p> <p><span class="hlt">Exchange</span> bias is observed in ferromagnetic/antiferromagnetic (FM/AF) layered stacks and in materials with neighboring ferromagnetic and antiferromagnetic granules. The latter is commonly observed in Ni-Mn-based martensitic Heusler alloys. In general, the <span class="hlt">exchange</span>-bias effect is identified as horizontally shifted hysteresis loop when the system is field cooled from high temperatures. We report here loop shifts not only under field-cooled but also under zero-field-cooled conditions in magnetically granular martensitic Ni50Mn50 -xSnx Heusler alloys in the compositional range 13.0 ≥x ≥8.9 . Under zero-field-cooled conditions, the initially applied field can carry the system over energy barriers and stabilize a spin-reconfigured state so that a negatively shifted hysteresis loop can also occur here as in the field-cooled state. Spin reconfiguration occurs when the relative size of the AF and FM regions as well as the relative strength of the of AF and FM interactions are in balance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12971407','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12971407"><span id="translatedtitle">In vivo and in vitro measurements of complex-type chromosomal <span class="hlt">exchanges</span> <span class="hlt">induced</span> by heavy ions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>George, K; Durante, M; Wu, H; Willingham, V; Cucinotta, F A</p> <p>2003-01-01</p> <p>Heavy ions are more efficient in producing complex-type chromosome <span class="hlt">exchanges</span> than sparsely ionizing radiation, and this can potentially be used as a biomarker of radiation quality. We measured the induction of complex-type chromosomal aberrations in human peripheral blood lymphocytes exposed in vitro to accelerated H-, He-, C-, Ar-, Fe- and Au-ions in the LET range of approximately 0.4-1400 keV/micrometers. Chromosomes were analyzed either at the first post-irradiation mitosis, or in interphase, following premature condensation by phosphatase inhibitors. Selected chromosomes were then visualized after FISH-painting. The dose-response curve for the induction of complex-type <span class="hlt">exchanges</span> by heavy ions was linear in the dose-range 0.2-1.5 Gy, while gamma-rays did not produce a significant increase in the yield of complex rearrangements in this dose range. The yield of complex aberrations after 1 Gy of heavy ions increased up to an LET around 100 keV/micrometers, and then declined at higher LET values. When mitotic cells were analyzed, the frequency of complex rearrangements after 1 Gy was about 10 times higher for Ar- or Fe- ions (the most effective ions, with LET around 100 keV/micrometers) than for 250 MeV protons, and values were about 35 times higher in prematurely condensed chromosomes. These results suggest that complex rearrangements may be detected in astronauts' blood lymphocytes after long-term space flight, because crews are exposed to HZE particles from galactic cosmic radiation. However, in a cytogenetic study of ten astronauts after long-term missions on the Mir or International Space Station, we found a very low frequency of complex rearrangements, and a significant post-flight increase was detected in only one out of the ten crewmembers. It appears that the use of complex-type <span class="hlt">exchanges</span> as biomarker of radiation quality in vivo after low-dose chronic exposure in mixed radiation fields is hampered by statistical uncertainties. PMID:12971407</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Nanos...5.6589M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Nanos...5.6589M"><span id="translatedtitle">Tunable properties <span class="hlt">induced</span> by ion <span class="hlt">exchange</span> in multilayer intertwined CuS microflowers with hierarchal structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mi, Liwei; Wei, Wutao; Zheng, Zhi; Gao, Yang; Liu, Yang; Chen, Weihua; Guan, Xinxin</p> <p>2013-06-01</p> <p>Novel hierarchical wool-ball-like copper sulfide (CuS) microflowers with a three-dimensional (3D) porous framework were successfully synthesized by the direct reaction of copper with sulfur powder using a one-pot in situ growth method at low temperature (60 °C). The CuS microflowers covered firmly the surface of the 3D porous framework. The formation mechanism was examined in detail by adjusting the amount of hydrochloric acid and reaction time. Most importantly, the chemical composition of the CuS microflowers was altered by the Se <span class="hlt">exchange</span> without changing their morphology and structure. In this way, pure CuSe and Cu1.8Se crystalline materials were obtained on the surface of the porous microtube at different reaction times and the appropriate amount of Se powder. And interestingly, the core material remained as CuS. This behavior greatly affects the physical and chemical properties of the materials. The catalytic ability of the as-obtained CuSe@CuS and CuSe1.8@CuS composite materials to degrade methylene blue and rhodamine B is several times greater than that of the as-synthesized CuS microflowers.Novel hierarchical wool-ball-like copper sulfide (CuS) microflowers with a three-dimensional (3D) porous framework were successfully synthesized by the direct reaction of copper with sulfur powder using a one-pot in situ growth method at low temperature (60 °C). The CuS microflowers covered firmly the surface of the 3D porous framework. The formation mechanism was examined in detail by adjusting the amount of hydrochloric acid and reaction time. Most importantly, the chemical composition of the CuS microflowers was altered by the Se <span class="hlt">exchange</span> without changing their morphology and structure. In this way, pure CuSe and Cu1.8Se crystalline materials were obtained on the surface of the porous microtube at different reaction times and the appropriate amount of Se powder. And interestingly, the core material remained as CuS. This behavior greatly affects the physical and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AdSpR..31.1525G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AdSpR..31.1525G"><span id="translatedtitle">In vivo and in vitro measurements of complex-type chromosomal <span class="hlt">exchanges</span> <span class="hlt">induced</span> by heavy ions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>George, K.; Durante, M.; Wu, H.; Willingham, V.; Cucinotta, F. A.</p> <p></p> <p>Heavy ions are more efficient in producing complex-type chromosome <span class="hlt">exchanges</span> than sparsely ionizing radiation, and this can potentially be used as a biomarker of radiation quality. We measured the induction of complex-type chromosomal aberrations in human peripheral blood lymphocytes exposed in vitro to accelerated H-, He-, C-, Ar-, Fe- and Au-ions in the LET range of approximately 4-1400 keV/μm Chromosomes were analyzed either at the first post-irradiation mitosis, or in interphase, following premature condensation by phosphatase inhibitors. Selected chromosomes were then visualized after FISH-painting. The dose-response curve for the induction of complex-type <span class="hlt">exchanges</span> by heavy ions was linear in the dose-range 0.2-1.5 Gym while γ-rays did not produce a significant increase in the yield of complex rearrangements in this dose range. The yield of complex aberrations after 1 Gy of heavy ions increased up to an LET around 100 keV/μm and then declined at higher LET values. When mitotic cells were analyzed, the frequency of complex rearrangements after 1 Gy was about 10 times higher for Ar- or Fe-ions (the most effective ions, with LET around 100 keV/μm than for 250 MeV protons, and values were about 35 times higher in prematurely condensed chromosomes. These results suggest that complex rearrangements may be detected in astronauts' blood lymphocytes after long-term space flight, because crews are exposed to HZE particles from galactic cosmic radiation. However, in a cytogenetic study of ten astronauts after long-term missions on the Mir or International Space Station, we found a very low frequency of complex rearrangements, and a significant post-flight increase was detected in only one out of the ten crewmembers. It appears that the use of complex-type <span class="hlt">exchanges</span> as biomarker of radiation quality in vivo after low-dose chronic exposure in mixed radiation fields is hampered by statistical uncertainties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16334263','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16334263"><span id="translatedtitle"><span class="hlt">Exchangeable</span> sodium <span class="hlt">induced</span> changes in yield, water relation and cation composition of fennel (Foeniculum vulgare Mill).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garg, V K; Singh, P K; Pushpangadan, P</p> <p>2005-06-01</p> <p>A pot experiment was conducted with the objectives to assess the adaptation potential of fennel crop grown at 10, 20, 25, 35 and 40 ESP (<span class="hlt">exchangeable</span> sodium percentage) levels. Results showed that the rate of seed germination, plant growth including branching pattern, umbels per plant and 1000 test seed weight were adversely affected by sodic soils. Assuming that fifty percent reduction in seed yield and Na+/K+ ratio in leaf tissue as an index of alkali tolerance revealed that fennel was tolerant up to 25 ESP. The cell sap pH and EC reflected optimum osmoticum maintenance to withstand sodicity stress at this level and beyond this leaf water potential decreased (negatively) more to impede water uptake.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26176908','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26176908"><span id="translatedtitle">Excess titanium dioxide nanoparticles on the cell surface <span class="hlt">induce</span> cytotoxicity by hindering ion <span class="hlt">exchange</span> and disrupting exocytosis processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yanli; Yao, Chenjie; Li, Chenchen; Ding, Lin; Liu, Jian; Dong, Peng; Fang, Haiping; Lei, Zhendong; Shi, Guosheng; Wu, Minghong</p> <p>2015-08-14</p> <p>To date, considerable effort has been devoted to determine the potential toxicity of nanoparticles to cells and organisms. However, determining the mechanism of cytotoxicity <span class="hlt">induced</span> by different types of nanoparticles remains challenging. Herein, typically low toxicity nanomaterials were used as a model to investigate the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials. We studied the effect of nano-TiO2, nano-Al2O3 and nano-SiO2 deposition films on the ion concentration on a cell-free system simulating the cell membrane. The results showed that the ion concentration of K(+), Ca(2+), Na(+), Mg(2+) and SO4(2-) decreased significantly following filtration of the prepared deposition films. More specifically, at a high nano-TiO2 concentration (200 mg L(-1)) and a long nano-TiO2 deposition time (48 h), the concentration of Na(+) decreased from 2958.01 to 2775.72, 2749.86, 2757.36, and 2719.82 mg L(-1), respectively, for the four types of nano-TiO2 studied. Likewise, the concentration of SO4(2-) decreased from 38.83 to 35.00, 35.80, 35.40, and 35.27 mg L(-1), respectively. The other two kinds of typical low toxicity nanomaterials (nano-Al2O3 and nano-SiO2) have a similar impact on the ion concentration change trend. Adsorption of ions on nanoparticles and the hydrated shell around the ions strongly hindered the ions through the nanoparticle films. The endocytosed nanoparticles could be released from the cells without <span class="hlt">inducing</span> cytotoxicity. Hindering the ion <span class="hlt">exchange</span> and disrupting the exocytosis process are the main factors that <span class="hlt">induce</span> cytotoxicity in the presence of excess nano-TiO2 on the cell surface. The current findings may offer a universal principle for understanding the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5064604','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5064604"><span id="translatedtitle">Exercise Attenuates Intermittent Hypoxia-<span class="hlt">Induced</span> Cardiac Fibrosis Associated with Sodium-Hydrogen <span class="hlt">Exchanger</span>-1 in Rats</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Tsung-I; Tu, Wei-Chia</p> <p>2016-01-01</p> <p>Purpose: To investigate the role of sodium–hydrogen <span class="hlt">exchanger</span>-1 (NHE-1) and exercise training on intermittent hypoxia-<span class="hlt">induced</span> cardiac fibrosis in obstructive sleep apnea (OSA), using an animal model mimicking the intermittent hypoxia of OSA. Methods: Eight-week-old male Sprague–Dawley rats were randomly assigned to control (CON), intermittent hypoxia (IH), exercise (EXE), or IH combined with exercise (IHEXE) groups. These groups were randomly assigned to subgroups receiving either a vehicle or the NHE-1 inhibitor cariporide. The EXE and IHEXE rats underwent exercise training on an animal treadmill for 10 weeks (5 days/week, 60 min/day, 24–30 m/min, 2–10% grade). The IH and IHEXE rats were exposed to 14 days of IH (30 s of hypoxia—nadir of 2–6% O2—followed by 45 s of normoxia) for 8 h/day. At the end of 10 weeks, rats were sacrificed and then hearts were removed to determine the myocardial levels of fibrosis index, oxidative stress, antioxidant capacity, and NHE-1 activation. Results: Compared to the CON rats, IH <span class="hlt">induced</span> higher cardiac fibrosis, lower myocardial catalase, and superoxidative dismutase activities, higher myocardial lipid and protein peroxidation and higher NHE-1 activation (p < 0.05 for each), which were all abolished by cariporide. Compared to the IH rats, lower cardiac fibrosis, higher myocardial antioxidant capacity, lower myocardial lipid, and protein peroxidation and lower NHE-1 activation were found in the IHEXE rats (p < 0.05 for each). Conclusion: IH-<span class="hlt">induced</span> cardiac fibrosis was associated with NHE-1 hyperactivity. However, exercise training and cariporide exerted an inhibitory effect to prevent myocardial NHE-1 hyperactivity, which contributed to reduced IH-<span class="hlt">induced</span> cardiac fibrosis. Therefore, NHE-1 plays a critical role in the effect of exercise on IH-<span class="hlt">induced</span> increased cardiac fibrosis. PMID:27790155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1253593','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1253593"><span id="translatedtitle">Ras activation of a Rac1 <span class="hlt">exchange</span> factor, Tiam1, mediates neurotrophin-3-<span class="hlt">induced</span> Schwann cell migration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yamauchi, Junji; Miyamoto, Yuki; Tanoue, Akito; Shooter, Eric M.; Chan, Jonah R.</p> <p>2005-01-01</p> <p>Endogenous neurotrophins positively and negatively regulate migration of premyelinating Schwann cells before the initiation of myelination. Neurotrophin-3 (NT3) acting through the TrkC receptor tyrosine kinase stimulates Schwann cell migration via the Rho GTPases Rac1 and Cdc42. We previously demonstrated that TrkC directly phosphorylates and activates Dbs, the guanine-nucleotide <span class="hlt">exchange</span> factor (GEF) for Cdc42, to partially mediate Schwann cell migration. Here, we identify T lymphoma invasion and metastasis (Tiam) 1 as the Rac1-specific guanine-nucleotide <span class="hlt">exchange</span> factor involved in NT3-<span class="hlt">induced</span> Schwann cell migration. Furthermore, the interaction between the small GTPase Ras and Tiam1 plays an essential role in the activation of Rac1. Taken together, these results suggest that NT3 activation of TrkC stimulates Schwann cell migration through two parallel signaling units, Ras/Tiam1/Rac1 and Dbs/Cdc42, and that Schwann cell migration is uniquely regulated in the case of Ras and Rac1, by two different types of small GTPases. PMID:16203995</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22486158','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22486158"><span id="translatedtitle">Spin dynamics <span class="hlt">induced</span> by ultrafast heating with ferromagnetic/antiferromagnetic interfacial <span class="hlt">exchange</span> in perpendicularly magnetized hard/soft bilayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ma, Q. L. E-mail: mizukami@wpi-aimr.tohoku.ac.jp; Miyazaki, T.; Mizukami, S. E-mail: mizukami@wpi-aimr.tohoku.ac.jp; Iihama, S.; Zhang, X. M.</p> <p>2015-11-30</p> <p>The laser-<span class="hlt">induced</span> spin dynamics of FeCo in perpendicularly magnetized L1{sub 0}-MnGa/FeCo bilayers with ferromagnetic and antiferromagnetic interfacial <span class="hlt">exchange</span> coupling (IEC) are examined using the time-resolved magneto-optical Kerr effect. We found a precessional phase reversal of the FeCo layer as the IEC changes from ferromagnetic to antiferromagnetic. Moreover, a precession-suspension window was observed when the magnetic field was applied in a certain direction for the bilayer with ferromagnetic IEC. Our observations reveal that the spin dynamics modulation is strongly dependent on the IEC type within the Landau-Lifshitz-Gilbert depiction. The IEC dependence of the precessional phase and amplitude suggests the interesting method for magnetization dynamics modulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/974629','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/974629"><span id="translatedtitle">The Ion-<span class="hlt">induced</span> Charge-<span class="hlt">exchange</span> X-ray Emission of the Jovian Auroras: Magnetospheric or Solar Wind Origin?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hui, Yawei; Schultz, David Robert; Kharchenko, Vasili A; Stancil, Phillip C.; Cravens, Thomas E. E.; Lisse, Carey M.; Dalgarno, A.</p> <p>2009-01-01</p> <p>A new and more comprehensive model of charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions ( 0.7-2 MeV/u), but infer a different relative sulfur to oxygen abundance ratio for these Chandra observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21335991','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21335991"><span id="translatedtitle">THE ION-<span class="hlt">INDUCED</span> CHARGE-<span class="hlt">EXCHANGE</span> X-RAY EMISSION OF THE JOVIAN AURORAS: MAGNETOSPHERIC OR SOLAR WIND ORIGIN?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hui Yawei; Schultz, David R.; Kharchenko, Vasili A.; Stancil, Phillip C.; Cravens, Thomas E.; Lisse, Carey M. E-mail: schultzd@ornl.gov E-mail: stancil@physast.uga.edu E-mail: carey.lisse@jhuapl.edu</p> <p>2009-09-10</p> <p>A new and more comprehensive model of charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions ({approx}0.7-2 MeV u{sup -1}), but infer a different relative sulfur-to-oxygen abundance ratio for these Chandra observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1521142','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1521142"><span id="translatedtitle">A study of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> and somatic cell mutation in hospital workers exposed to ethylene oxide.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tomkins, D J; Haines, T; Lawrence, M; Rosa, N</p> <p>1993-01-01</p> <p>To investigate the risks of exposure to ethylene oxide (EO) at current permissible levels and at past higher levels, an inception cohort of sterilizer operators and supervisors from the Central Processing Department (CPD), respiratory therapists, and engineers exposed to EO were identified at the McMaster University Medical Centre. A comparison group from Nutrition Services (NUTR) were matched with the CPD workers on the basis of sex, age, and smoking habit. The present report is based on genetic test results for the 94 CPD and matched NUTR workers only. Statistical analysis based on the mean SCE frequency in the top 5, top 10, and all cells (50 cells scored per individual) and high frequency cells (HFC) based on the 95th percentile for nonsmoking control subjects showed a direct association with current smoking but not with EO exposure. Similarly, statistical analysis of the somatic cell mutation (SCMT) variant frequencies did not demonstrate an association with EO exposure, nor with smoking. Regression analysis indicated that sex was the only other covariate that significantly affected SCE. Age was weakly associated with SCMT. A statistically significant interaction between occupational exposure and smoking habits was observed only for the mean SCE frequency of the top 5 and top 10 cells when the 11 current CPD/NUTR pairs were not included. Thus, this interaction should be interpreted with caution. PMID:8143611</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24844569','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24844569"><span id="translatedtitle">On-line stable isotope gas <span class="hlt">exchange</span> reveals an <span class="hlt">inducible</span> but leaky carbon concentrating mechanism in Nannochloropsis salina.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hanson, David T; Collins, Aaron M; Jones, Howland D T; Roesgen, John; Lopez-Nieves, Samuel; Timlin, Jerilyn A</p> <p>2014-09-01</p> <p>Carbon concentrating mechanisms (CCMs) are common among microalgae, but their regulation and even existence in some of the most promising biofuel production strains is poorly understood. This is partly because screening for new strains does not commonly include assessment of CCM function or regulation despite its fundamental role in primary carbon metabolism. In addition, the <span class="hlt">inducible</span> nature of many microalgal CCMs means that environmental conditions should be considered when assessing CCM function and its potential impact on biofuels. In this study, we address the effect of environmental conditions by combining novel, high frequency, on-line (13)CO2 gas <span class="hlt">exchange</span> screen with microscope-based lipid characterization to assess CCM function in Nannochloropsis salina and its interaction with lipid production. Regulation of CCM function was explored by changing the concentration of CO2 provided to continuous cultures in airlift bioreactors where cell density was kept constant across conditions by controlling the rate of media supply. Our isotopic gas <span class="hlt">exchange</span> results were consistent with N. salina having an <span class="hlt">inducible</span> "pump-leak" style CCM similar to that of Nannochloropsis gaditana. Though cells grew faster at high CO2 and had higher rates of net CO2 uptake, we did not observe significant differences in lipid content between conditions. Since the rate of CO2 supply was much higher for the high CO2 conditions, we calculated that growing cells bubbled with low CO2 is about 40 % more efficient for carbon capture than bubbling with high CO2. We attribute this higher efficiency to the activity of a CCM under low CO2 conditions. PMID:24844569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5042380','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5042380"><span id="translatedtitle">Loss of Sodium/Hydrogen <span class="hlt">Exchanger</span> NHA2 Exacerbates Obesity- and Aging-<span class="hlt">Induced</span> Glucose Intolerance in Mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Deisl, Christine; Anderegg, Manuel; Albano, Giuseppe; Lüscher, Benjamin P.; Cerny, David; Soria, Rodrigo; Bouillet, Elisa; Rimoldi, Stefano; Scherrer, Urs</p> <p>2016-01-01</p> <p>We previously demonstrated that the sodium/hydrogen <span class="hlt">exchanger</span> NHA2, also known as NHEDC2 or SLC9B2, is critical for insulin secretion by β–cells. To gain more insights into the role of NHA2 on systemic glucose homeostasis, we studied the impact of loss of NHA2 during the physiological aging process and in the setting of diet-<span class="hlt">induced</span> obesity. While glucose tolerance was normal at 2 months of age, NHA2 KO mice displayed a significant glucose intolerance at 5 and 12 months of age, respectively. An obesogenic high fat diet further exacerbated the glucose intolerance of NHA2 KO mice. Insulin levels remained similar in NHA2 KO and WT mice during aging and high fat diet, but fasting insulin/glucose ratios were significantly lower in NHA2 KO mice. Peripheral insulin sensitivity, measured by insulin tolerance tests and hyperinsulinemic euglycemic clamps, was unaffected by loss of NHA2 during aging and high fat diet. High fat diet diminished insulin secretion capacity in both WT and NHA2 KO islets and reduced expression of NHA2 in WT islets. In contrast, aging was characterized by a gradual increase of NHA2 expression in islets, paralleled by an increasing difference in insulin secretion between WT and NHA2 KO islets. In summary, our results demonstrate that loss of the sodium/hydrogen <span class="hlt">exchanger</span> NHA2 exacerbates obesity- and aging-<span class="hlt">induced</span> glucose intolerance in mice. Furthermore, our data reveal a close link between NHA2 expression and insulin secretion capacity in islets. PMID:27685945</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AdSpR..27..383K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AdSpR..27..383K"><span id="translatedtitle">G2-chromosome aberrations <span class="hlt">induced</span> by high-LET radiations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Ito, H.; Wu, H.; Cucinotta, F. A.</p> <p></p> <p>We report measurements of initial G2-<span class="hlt">chromatid</span> breaks in normal human fibroblasts exposed to various types of high-LET particles. Exponentially growing AG 1522 cells were exposed to γ-rays or heavy ions. Chromosomes were prematurely condensed by calyculin A. <span class="hlt">Chromatid</span>-type breaks and isochromatid-type breaks were scored separately. The dose response curves for the induction of total <span class="hlt">chromatid</span> breaks (<span class="hlt">chromatid</span>-type + isochromatid-type) and <span class="hlt">chromatid</span>-type breaks were linear for each type of radiation. However, dose response curves for the induction of isochromatid-type breaks were linear for high-LET radiations and linear-quadratic for γ-rays. Relative biological effectiveness (RBE), calculated from total breaks, showed a LET dependent tendency with a peak at 55 keV/μm silicon (2.7) or 80 keV/μm carbon (2.7) and then decreased with LET (1.5 at 440 keV/μm). RBE for <span class="hlt">chromatid</span>-type break peaked at 55 keV/μm (2.4) then decreased rapidly with LET. The RBE of 440 keV/μm iron particles was 0.7. The RBE calculated from induction of isochromatid-type breaks was much higher for high-LET radiations. It is concluded that the increased production of isochromatid-type breaks, <span class="hlt">induced</span> by the densely ionizing track structure, is a signature of high-LET radiation exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1206447','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1206447"><span id="translatedtitle">Cis-Acting Determinants Affecting Centromere Function, Sister-<span class="hlt">Chromatid</span> Cohesion and Reciprocal Recombination during Meiosis in Saccharomyces Cerevisiae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sears, D. D.; Hegemann, J. H.; Shero, J. H.; Hieter, P.</p> <p>1995-01-01</p> <p>We have employed a system that utilizes homologous pairs of human DNA-derived yeast artificial chromosomes (YACs) as marker chromosomes to assess the specific role (s) of conserved centromere DNA elements (CDEI, CDEII and CDEIII) in meiotic chromosome disjunction fidelity. Thirteen different centromere (CEN) mutations were tested for their effects on meiotic centromere function. YACs containing a wild-type CEN DNA sequence segregate with high fidelity in meiosis I (99% normal segregation) and in meiosis II (96% normal segregation). YACs containing a 31-bp deletion mutation in centromere DNA element II (CDEIIδ31) in either a heterocentric (mutant/wild type), homocentric (mutant/mutant) or monosomic (mutant/--) YAC pair configuration exhibited high levels (16-28%) of precocious sister-<span class="hlt">chromatid</span> segregation (PSS) and increased levels (1-6%) of nondisjunction meiosis I (NDI). YACs containing this mutation also exhibit high levels (21%) of meiosis II nondisjunction. Interestingly, significant alterations in homolog recombination frequency were observed in the exceptional PSS class of tetrads, suggesting unusual interactions between prematurely separated sister <span class="hlt">chromatids</span> and their homologous nonsister <span class="hlt">chromatids</span>. We also have assessed the meiotic segregation effects of rare gene conversion events occurring at sites located immediately adjacent to or distantly from the centromere region. Proximal gene conversion events were associated with extremely high levels (60%) of meiosis I segregation errors (including both PSS and NDI), whereas distal events had no apparent effect. Taken together, our results indicate a critical role for CDEII in meiosis and underscore the importance of maintaining sister-<span class="hlt">chromatid</span> cohesion for proper recombination in meiotic prophase and for proper disjunction in meiosis I. PMID:7768430</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/75589','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/75589"><span id="translatedtitle">Cis-acting determinants affecting centromere function, sister-<span class="hlt">chromatid</span> cohesion and reciprocal recombination during meiosis in Saccharomyces cerevisiae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sears, D.D.; Hieter, P.; Shero, J.H. |; Hegemann, J.H.</p> <p>1995-03-01</p> <p>We have employed a system that utilizes homologous pairs of human DNA-derived yeast artificial chromosomes (YACs) as marker chromosomes to assess the specific role(s) of conserved centromere DNA elements (CDEI, CDEII, and CDEIII) in meiotic chromosome disjunction fidelity. Thirteen different centromere (CEN) mutations were tested for their effects on meiotic centromere function. YACs containing a wild-type CEN DNA sequence segregate with high fidelity in meiosis I (99% normal segregation) and in meiosis II (96% normal segregation). YACs containing a 31-bp deletion mutation in centromere DNA element II (CDEII{Delta}31) in either a heterocentric (mutant/wild type), homocentric (mutant/mutant) or monosomic (mutant/-) YAC pair configuration exhibited high levels (16-28%) of precocious sister-<span class="hlt">chromatid</span> segregation (PSS) and increased levels (1-6%) of nondisjunction meiosis I (NDI). YACs containing this mutation also exhibit high levels (21%) of meiosis II nondisjunction. Interestingly, significant alterations in homolog recombination frequency were observed in the exceptional PSS class of tetrads, suggesting unusual interactions between prematurely separated sister <span class="hlt">chromatids</span> and their homologous nonsister <span class="hlt">chromatids</span>. We also have assessed the meiotic segregation effects of rare gene conversion events occurring at sites located immediately adjacent to or distantly from the centromere region. Proximal gene conversion events were associated with extremely high levels (60%) of meiosis I segregation errors (including both PSS and NDI), whereas distal events had no apparent effect. Taken together, our results indicate a critical role for CDEII in meiosis and underscore the importance of maintaining sister-<span class="hlt">chromatid</span> cohesion for proper recombination in meiotic prophase and for proper disjunction in meiosis I. 49 refs., 4 figs., 5 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13E..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13E..04S"><span id="translatedtitle">Modeling coupled thermal-mechanical processes of frozen soil <span class="hlt">induced</span> by borehole heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shao, H.</p> <p>2015-12-01</p> <p>To utilize the shallow geothermal energy, heat pumps are often coupled with Borehole Heat <span class="hlt">Exchangers</span> (BHE) to provide heating and cooling for buildings. In cold regions, soil freezing around the BHE is a potential problem which will dramatically influence the underground soil temperature distribution, subsequently the inlet and outlet refrigerant temperature of the BHE, and finally the efficiency of the heat pump. In this study, a numerical model has been developed to simulate the coupled temperature evolution both inside the BHE, and the propagating freezing front in the surrounding soil. The coupled model was validated against analytical solutions and experimental data. The influence of the freezing process on the overall system performance is investigated by comparing one long BHE configuration without freezing and another short one with latent heat from the frozen groundwater. It is found that when freezing happens, the coefficient of performance (COP) of the heat pump will decrease by around 0.5, leading to more electricity consumption. Furthermore, analysis of the simulation result reveals that the exploitation of latent heat through groundwater freezing is only economically attractive if electricity price is low and interest rate high, and it is not the case is most European countries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PPCF...55l4006M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PPCF...55l4006M"><span id="translatedtitle">Unstable ring-shaped ion distribution functions <span class="hlt">induced</span> by charge-<span class="hlt">exchange</span> collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miloch, W. J.; Pécseli, H. L.; Trulsen, J. K.</p> <p>2013-12-01</p> <p>The stability of ion velocity distributions in magnetized plasmas is studied under conditions where the plasma has an E0 × B/B2-drift with respect to a neutral background. Charge-<span class="hlt">exchange</span> collisions can give rise to velocity distributions having the form of a ring or a loss-cone that can become linearly unstable. Sometimes the distributions have distorted forms and a stability analysis is not straightforward. Numerical simulations offer the most convenient method of a stability analysis in such cases. By numerical simulations using a particle-in-cell code that includes collisional interactions we demonstrate the formation of such velocity distributions and study the instabilities associated with them. We observe the saturation of the linear instability by quasi-linear velocity space diffusion. The parameter dependence of the instability conditions is illustrated by examples. The results are relevant for explaining some of the low frequency oscillations observed in the lower parts of the Earth's ionosphere (E- and F-regions), where collisions with neutrals are abundant. The results are important for laboratory experiments as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MAR.Z7001C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MAR.Z7001C"><span id="translatedtitle"><span class="hlt">Exchange</span> <span class="hlt">induced</span> electron transport in heavily n-doped Si nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Joonyeon; Park, Tae-Eon; Min, Byoung-Chul; Kim, Ilsoo; Yang, Jae-Eun; Jo, Moon-Ho; Choi, Heon-Jin</p> <p>2012-02-01</p> <p>Silicon nanowires (Si NWs) have been used as building blocks in the ``bottom-up'' approach to nanoelectronics because of their excellent electrical properties. Despite the potential of Si NWs, unfortunately, there is little known about the electrical properties of heavily doped Si NWs. We have synthesized heavily doped n-type Si NWs and measured the electrical resistance using four-probe method. As we decrease the temperature, the resistivity of Si NWs decreases initially, shows a resistivity minimum around 60 K, and thereafter increases logarithmically. Below the resistivity minimum temperature (Tmin), we have observed a dip around zero-bias in the differential conductance, and a negative magnetoresistance (MR) which depends on the angle between the applied magnetic field and current flow. These results are associated with the impurity band conduction and electron scattering by the localized spins at phosphorus donor states. The analysis on the MR reveals that the localized spins are coupled antiferromagnetically at low temperature via the <span class="hlt">exchange</span> interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24905797','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24905797"><span id="translatedtitle">Cation- and anion-<span class="hlt">exchanges</span> <span class="hlt">induce</span> multiple distinct rearrangements within metallosupramolecular architectures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Riddell, Imogen A; Ronson, Tanya K; Clegg, Jack K; Wood, Christopher S; Bilbeisi, Rana A; Nitschke, Jonathan R</p> <p>2014-07-01</p> <p>Different anionic templates act to give rise to four distinct Cd(II)-based architectures: a Cd2L3 helicate, a Cd8L12 distorted cuboid, a Cd10L15 pentagonal prism, and a Cd12L18 hexagonal prism, which respond to both anionic and cationic components. Interconversions between architectures are driven by the addition of anions that bind more strongly within a given product framework. The addition of Fe(II) prompted metal <span class="hlt">exchange</span> and transformation to a Fe4L6 tetrahedron or a Fe10L15 pentagonal prism, depending on the anionic templates present. The equilibrium between the Cd12L18 prism and the Cd2L3 triple helicate displayed concentration dependence, with higher concentrations favoring the prism. The Cd12L18 structure serves as an intermediate en route to a hexafluoroarsenate-templated Cd10L15 complex, whereby the structural features of the hexagonal prism preorganize the system to form the structurally related pentagonal prism. In addition to the interconversion pathways investigated, we also report the single-crystal X-ray structure of bifluoride encapsulated within a Cd10L15 complex and report solution state data for J-coupling through a CH···F(-) hydrogen bond indicating the strength of these interactions in solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26044958','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26044958"><span id="translatedtitle">Variations in dysfunction of sister <span class="hlt">chromatid</span> cohesion in esco2 mutant zebrafish reflect the phenotypic diversity of Roberts syndrome.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Percival, Stefanie M; Thomas, Holly R; Amsterdam, Adam; Carroll, Andrew J; Lees, Jacqueline A; Yost, H Joseph; Parant, John M</p> <p>2015-08-01</p> <p>Mutations in ESCO2, one of two establishment of cohesion factors necessary for proper sister <span class="hlt">chromatid</span> cohesion (SCC), cause a spectrum of developmental defects in the autosomal-recessive disorder Roberts syndrome (RBS), warranting in vivo analysis of the consequence of cohesion dysfunction. Through a genetic screen in zebrafish targeting embryonic-lethal mutants that have increased genomic instability, we have identified an esco2 mutant zebrafish. Utilizing the natural transparency of zebrafish embryos, we have developed a novel technique to observe chromosome dynamics within a single cell during mitosis in a live vertebrate embryo. Within esco2 mutant embryos, we observed premature <span class="hlt">chromatid</span> separation, a unique chromosome scattering, prolonged mitotic delay, and genomic instability in the form of anaphase bridges and micronuclei formation. Cytogenetic studies indicated complete <span class="hlt">chromatid</span> separation and high levels of aneuploidy within mutant embryos. Amongst aneuploid spreads, we predominantly observed decreases in chromosome number, suggesting that either cells with micronuclei or micronuclei themselves are eliminated. We also demonstrated that the genomic instability leads to p53-dependent neural tube apoptosis. Surprisingly, although many cells required Esco2 to establish cohesion, 10-20% of cells had only weakened cohesion in the absence of Esco2, suggesting that compensatory cohesion mechanisms exist in these cells that undergo a normal mitotic division. These studies provide a unique in vivo vertebrate view of the mitotic defects and consequences of cohesion establishment loss, and they provide a compensation-based model to explain the RBS phenotypes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26044958','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26044958"><span id="translatedtitle">Variations in dysfunction of sister <span class="hlt">chromatid</span> cohesion in esco2 mutant zebrafish reflect the phenotypic diversity of Roberts syndrome.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Percival, Stefanie M; Thomas, Holly R; Amsterdam, Adam; Carroll, Andrew J; Lees, Jacqueline A; Yost, H Joseph; Parant, John M</p> <p>2015-08-01</p> <p>Mutations in ESCO2, one of two establishment of cohesion factors necessary for proper sister <span class="hlt">chromatid</span> cohesion (SCC), cause a spectrum of developmental defects in the autosomal-recessive disorder Roberts syndrome (RBS), warranting in vivo analysis of the consequence of cohesion dysfunction. Through a genetic screen in zebrafish targeting embryonic-lethal mutants that have increased genomic instability, we have identified an esco2 mutant zebrafish. Utilizing the natural transparency of zebrafish embryos, we have developed a novel technique to observe chromosome dynamics within a single cell during mitosis in a live vertebrate embryo. Within esco2 mutant embryos, we observed premature <span class="hlt">chromatid</span> separation, a unique chromosome scattering, prolonged mitotic delay, and genomic instability in the form of anaphase bridges and micronuclei formation. Cytogenetic studies indicated complete <span class="hlt">chromatid</span> separation and high levels of aneuploidy within mutant embryos. Amongst aneuploid spreads, we predominantly observed decreases in chromosome number, suggesting that either cells with micronuclei or micronuclei themselves are eliminated. We also demonstrated that the genomic instability leads to p53-dependent neural tube apoptosis. Surprisingly, although many cells required Esco2 to establish cohesion, 10-20% of cells had only weakened cohesion in the absence of Esco2, suggesting that compensatory cohesion mechanisms exist in these cells that undergo a normal mitotic division. These studies provide a unique in vivo vertebrate view of the mitotic defects and consequences of cohesion establishment loss, and they provide a compensation-based model to explain the RBS phenotypes. PMID:26044958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4527282','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4527282"><span id="translatedtitle">Variations in dysfunction of sister <span class="hlt">chromatid</span> cohesion in esco2 mutant zebrafish reflect the phenotypic diversity of Roberts syndrome</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Percival, Stefanie M.; Thomas, Holly R.; Amsterdam, Adam; Carroll, Andrew J.; Lees, Jacqueline A.; Yost, H. Joseph; Parant, John M.</p> <p>2015-01-01</p> <p>ABSTRACT Mutations in ESCO2, one of two establishment of cohesion factors necessary for proper sister <span class="hlt">chromatid</span> cohesion (SCC), cause a spectrum of developmental defects in the autosomal-recessive disorder Roberts syndrome (RBS), warranting in vivo analysis of the consequence of cohesion dysfunction. Through a genetic screen in zebrafish targeting embryonic-lethal mutants that have increased genomic instability, we have identified an esco2 mutant zebrafish. Utilizing the natural transparency of zebrafish embryos, we have developed a novel technique to observe chromosome dynamics within a single cell during mitosis in a live vertebrate embryo. Within esco2 mutant embryos, we observed premature <span class="hlt">chromatid</span> separation, a unique chromosome scattering, prolonged mitotic delay, and genomic instability in the form of anaphase bridges and micronuclei formation. Cytogenetic studies indicated complete <span class="hlt">chromatid</span> separation and high levels of aneuploidy within mutant embryos. Amongst aneuploid spreads, we predominantly observed decreases in chromosome number, suggesting that either cells with micronuclei or micronuclei themselves are eliminated. We also demonstrated that the genomic instability leads to p53-dependent neural tube apoptosis. Surprisingly, although many cells required Esco2 to establish cohesion, 10-20% of cells had only weakened cohesion in the absence of Esco2, suggesting that compensatory cohesion mechanisms exist in these cells that undergo a normal mitotic division. These studies provide a unique in vivo vertebrate view of the mitotic defects and consequences of cohesion establishment loss, and they provide a compensation-based model to explain the RBS phenotypes. PMID:26044958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27397686','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27397686"><span id="translatedtitle">Ctf4 Links DNA Replication with Sister <span class="hlt">Chromatid</span> Cohesion Establishment by Recruiting the Chl1 Helicase to the Replisome.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Samora, Catarina P; Saksouk, Julie; Goswami, Panchali; Wade, Ben O; Singleton, Martin R; Bates, Paul A; Lengronne, Armelle; Costa, Alessandro; Uhlmann, Frank</p> <p>2016-08-01</p> <p>DNA replication during S phase is accompanied by establishment of sister <span class="hlt">chromatid</span> cohesion to ensure faithful chromosome segregation. The Eco1 acetyltransferase, helped by factors including Ctf4 and Chl1, concomitantly acetylates the chromosomal cohesin complex to stabilize its cohesive links. Here we show that Ctf4 recruits the Chl1 helicase to the replisome via a conserved interaction motif that Chl1 shares with GINS and polymerase α. We visualize recruitment by EM analysis of a reconstituted Chl1-Ctf4-GINS assembly. The Chl1 helicase facilitates replication fork progression under conditions of nucleotide depletion, partly independently of Ctf4 interaction. Conversely, Ctf4 interaction, but not helicase activity, is required for Chl1's role in sister <span class="hlt">chromatid</span> cohesion. A physical interaction between Chl1 and the cohesin complex during S phase suggests that Chl1 contacts cohesin to facilitate its acetylation. Our results reveal how Ctf4 forms a replisomal interaction hub that coordinates replication fork progression and sister <span class="hlt">chromatid</span> cohesion establishment. PMID:27397686</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24797474','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24797474"><span id="translatedtitle">Meiotic cohesin STAG3 is required for chromosome axis formation and sister <span class="hlt">chromatid</span> cohesion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Winters, Tristan; McNicoll, Francois; Jessberger, Rolf</p> <p>2014-06-01</p> <p>The cohesin complex is essential for mitosis and meiosis. The specific meiotic roles of individual cohesin proteins are incompletely understood. We report in vivo functions of the only meiosis-specific STAG component of cohesin, STAG3. Newly generated STAG3-deficient mice of both sexes are sterile with meiotic arrest. In these mice, meiotic chromosome architecture is severely disrupted as no bona fide axial elements (AE) form and homologous chromosomes do not synapse. Axial element protein SYCP3 forms dot-like structures, many partially overlapping with centromeres. Asynapsis marker HORMAD1 is diffusely distributed throughout the chromatin, and SYCP1, which normally marks synapsed axes, is largely absent. Centromeric and telomeric sister <span class="hlt">chromatid</span> cohesion are impaired. Centromere and telomere clustering occurs in the absence of STAG3, and telomere structure is not severely affected. Other cohesin proteins are present, localize throughout the STAG3-devoid chromatin, and form complexes with cohesin SMC1β. No other deficiency in a single meiosis-specific cohesin causes a phenotype as drastic as STAG3 deficiency. STAG3 emerges as the key STAG cohesin involved in major functions of meiotic cohesin. PMID:24797474</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24086141','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24086141"><span id="translatedtitle">Histone chaperone NAP1 mediates sister <span class="hlt">chromatid</span> resolution by counteracting protein phosphatase 2A.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moshkin, Yuri M; Doyen, Cecile M; Kan, Tsung-Wai; Chalkley, Gillian E; Sap, Karen; Bezstarosti, Karel; Demmers, Jeroen A; Ozgur, Zeliha; van Ijcken, Wilfred F J; Verrijzer, C Peter</p> <p>2013-01-01</p> <p>Chromosome duplication and transmission into daughter cells requires the precisely orchestrated binding and release of cohesin. We found that the Drosophila histone chaperone NAP1 is required for cohesin release and sister <span class="hlt">chromatid</span> resolution during mitosis. Genome-wide surveys revealed that NAP1 and cohesin co-localize at multiple genomic loci. Proteomic and biochemical analysis established that NAP1 associates with the full cohesin complex, but it also forms a separate complex with the cohesin subunit stromalin (SA). NAP1 binding to cohesin is cell-cycle regulated and increases during G2/M phase. This causes the dissociation of protein phosphatase 2A (PP2A) from cohesin, increased phosphorylation of SA and cohesin removal in early mitosis. PP2A depletion led to a loss of centromeric cohesion. The distinct mitotic phenotypes caused by the loss of either PP2A or NAP1, were both rescued by their concomitant depletion. We conclude that the balanced antagonism between NAP1 and PP2A controls cohesin dissociation during mitosis. PMID:24086141</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1635493','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1635493"><span id="translatedtitle">Effects of sister <span class="hlt">chromatid</span> cohesion proteins on cut gene expression during wing development in Drosophila</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dorsett, Dale; Eissenberg, Joel C.; Misulovin, Ziva; Martens, Andrew; Redding, Bethany; McKim, Kim</p> <p>2006-01-01</p> <p>Summary The cohesin protein complex is a conserved structural component of chromosomes. Cohesin binds numerous sites along interphase chromosomes and is essential for sister <span class="hlt">chromatid</span> cohesion and DNA repair. Here, we test the idea that cohesin also regulates gene expression. This idea arose from the finding that the Drosophila Nipped-B protein, a functional homolog of the yeast Scc2 factor that loads cohesin onto chromosomes, facilitates the transcriptional activation of certain genes by enhancers located many kilobases away from their promoters. We find that cohesin binds between a remote wing margin enhancer and the promoter at the cut locus in cultured cells, and that reducing the dosage of the Smc1 cohesin subunit increases cut expression in the developing wing margin. We also find that cut expression is increased by a unique pds5 gene mutation that reduces the binding of cohesin to chromosomes. On the basis of these results, we posit that cohesin inhibits long-range activation of the Drosophila cut gene, and that Nipped-B facilitates activation by regulating cohesin-chromosome binding. Such effects of cohesin on gene expression could be responsible for many of the developmental deficits that occur in Cornelia de Lange syndrome, which is caused by mutations in the human homolog of Nipped-B. PMID:16207752</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26423134','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26423134"><span id="translatedtitle">Defective sister <span class="hlt">chromatid</span> cohesion is synthetically lethal with impaired APC/C function.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Lange, Job; Faramarz, Atiq; Oostra, Anneke B; de Menezes, Renee X; van der Meulen, Ida H; Rooimans, Martin A; Rockx, Davy A; Brakenhoff, Ruud H; van Beusechem, Victor W; King, Randall W; de Winter, Johan P; Wolthuis, Rob M F</p> <p>2015-01-01</p> <p>Warsaw breakage syndrome (WABS) is caused by defective DDX11, a DNA helicase that is essential for <span class="hlt">chromatid</span> cohesion. Here, a paired genome-wide siRNA screen in patient-derived cell lines reveals that WABS cells do not tolerate partial depletion of individual APC/C subunits or the spindle checkpoint inhibitor p31(comet). A combination of reduced cohesion and impaired APC/C function also leads to fatal mitotic arrest in diploid RPE1 cells. Moreover, WABS cell lines, and several cancer cell lines with cohesion defects, display a highly increased response to a new cell-permeable APC/C inhibitor, apcin, but not to the spindle poison paclitaxel. Synthetic lethality of APC/C inhibition and cohesion defects strictly depends on a functional mitotic spindle checkpoint as well as on intact microtubule pulling forces. This indicates that the underlying mechanism involves cohesion fatigue in response to mitotic delay, leading to spindle checkpoint re-activation and lethal mitotic arrest. Our results point to APC/C inhibitors as promising therapeutic agents targeting cohesion-defective cancers. PMID:26423134</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4600715','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4600715"><span id="translatedtitle">Defective sister <span class="hlt">chromatid</span> cohesion is synthetically lethal with impaired APC/C function</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>de Lange, Job; Faramarz, Atiq; Oostra, Anneke B.; de Menezes, Renee X.; van der Meulen, Ida H.; Rooimans, Martin A.; Rockx, Davy A.; Brakenhoff, Ruud H.; van Beusechem, Victor W.; King, Randall W.; de Winter, Johan P.; Wolthuis, Rob M. F.</p> <p>2015-01-01</p> <p>Warsaw breakage syndrome (WABS) is caused by defective DDX11, a DNA helicase that is essential for <span class="hlt">chromatid</span> cohesion. Here, a paired genome-wide siRNA screen in patient-derived cell lines reveals that WABS cells do not tolerate partial depletion of individual APC/C subunits or the spindle checkpoint inhibitor p31comet. A combination of reduced cohesion and impaired APC/C function also leads to fatal mitotic arrest in diploid RPE1 cells. Moreover, WABS cell lines, and several cancer cell lines with cohesion defects, display a highly increased response to a new cell-permeable APC/C inhibitor, apcin, but not to the spindle poison paclitaxel. Synthetic lethality of APC/C inhibition and cohesion defects strictly depends on a functional mitotic spindle checkpoint as well as on intact microtubule pulling forces. This indicates that the underlying mechanism involves cohesion fatigue in response to mitotic delay, leading to spindle checkpoint re-activation and lethal mitotic arrest. Our results point to APC/C inhibitors as promising therapeutic agents targeting cohesion-defective cancers. PMID:26423134</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686863','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686863"><span id="translatedtitle">PICH promotes sister <span class="hlt">chromatid</span> disjunction and co-operates with topoisomerase II in mitosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nielsen, Christian F.; Huttner, Diana; Bizard, Anna H.; Hirano, Seiki; Li, Tian-Neng; Palmai-Pallag, Timea; Bjerregaard, Victoria A.; Liu, Ying; Nigg, Erich A.; Wang, Lily Hui-Ching; Hickson, Ian D.</p> <p>2015-01-01</p> <p>PICH is a SNF2 family DNA translocase that binds to ultra-fine DNA bridges (UFBs) in mitosis. Numerous roles for PICH have been proposed from protein depletion experiments, but a consensus has failed to emerge. Here, we report that deletion of PICH in avian cells causes chromosome structural abnormalities, and hypersensitivity to an inhibitor of Topoisomerase II (Topo II), ICRF-193. ICRF-193-treated PICH−/− cells undergo sister <span class="hlt">chromatid</span> non-disjunction in anaphase, and frequently abort cytokinesis. PICH co-localizes with Topo IIα on UFBs and at the ribosomal DNA locus, and the timely resolution of both structures depends on the ATPase activity of PICH. Purified PICH protein strongly stimulates the catalytic activity of Topo II in vitro. Consistent with this, a human PICH−/− cell line exhibits chromosome instability and chromosome condensation and decatenation defects similar to those of ICRF-193-treated cells. We propose that PICH and Topo II cooperate to prevent chromosome missegregation events in mitosis. PMID:26643143</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26643143','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26643143"><span id="translatedtitle">PICH promotes sister <span class="hlt">chromatid</span> disjunction and co-operates with topoisomerase II in mitosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nielsen, Christian F; Huttner, Diana; Bizard, Anna H; Hirano, Seiki; Li, Tian-Neng; Palmai-Pallag, Timea; Bjerregaard, Victoria A; Liu, Ying; Nigg, Erich A; Wang, Lily Hui-Ching; Hickson, Ian D</p> <p>2015-01-01</p> <p>PICH is a SNF2 family DNA translocase that binds to ultra-fine DNA bridges (UFBs) in mitosis. Numerous roles for PICH have been proposed from protein depletion experiments, but a consensus has failed to emerge. Here, we report that deletion of PICH in avian cells causes chromosome structural abnormalities, and hypersensitivity to an inhibitor of Topoisomerase II (Topo II), ICRF-193. ICRF-193-treated PICH(-/-) cells undergo sister <span class="hlt">chromatid</span> non-disjunction in anaphase, and frequently abort cytokinesis. PICH co-localizes with Topo IIα on UFBs and at the ribosomal DNA locus, and the timely resolution of both structures depends on the ATPase activity of PICH. Purified PICH protein strongly stimulates the catalytic activity of Topo II in vitro. Consistent with this, a human PICH(-/-) cell line exhibits chromosome instability and chromosome condensation and decatenation defects similar to those of ICRF-193-treated cells. We propose that PICH and Topo II cooperate to prevent chromosome missegregation events in mitosis. PMID:26643143</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3838905','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3838905"><span id="translatedtitle">BRCA1 and CtIP suppress long tract gene conversion between sister <span class="hlt">chromatids</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chandramouly, Gurushankar; Kwok, Amy; Huang, Bin; Willis, Nicholas A.; Xie, Anyong; Scully, Ralph</p> <p>2013-01-01</p> <p>BRCA1 controls early steps of the synthesis-dependent strand annealing (SDSA) pathway of homologous recombination, but has no known role following Rad51-mediated synapsis. Here we show that BRCA1 influences post-synaptic homologous recombination events, controlling the balance between short- (STGC) and long-tract gene conversion (LTGC) between sister <span class="hlt">chromatids</span>. Brca1 mutant cells reveal a bias towards LTGC that is corrected by expression of wild type but not cancer-predisposing BRCA1 alleles. The LTGC bias is enhanced by depletion of CtIP but reversed by inhibition of 53BP1, implicating DNA end resection as a contributor to the STGC/LTGC balance. The impact of BRCA1/CtIP loss on the STGC/LTGC balance is abolished when the second (non-invading) end of the break is unable to support termination of STGC by homologous pairing (“annealing”). This suggests that BRCA1/CtIP-mediated processing of the second end of the break controls the annealing step that normally terminates SDSA, thereby suppressing the error-prone LTGC outcome. PMID:23994874</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRG..115.3026S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRG..115.3026S"><span id="translatedtitle">Carbon dioxide <span class="hlt">exchange</span> in a semidesert grassland through drought-<span class="hlt">induced</span> vegetation change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scott, Russell L.; Hamerlynck, Erik P.; Jenerette, G. Darrel; Moran, M. Susan; Barron-Gafford, Greg A.</p> <p>2010-09-01</p> <p>Global warming may intensify the hydrological cycle and lead to increased drought severity and duration, which could alter plant community structure and subsequent ecosystem water and carbon dioxide cycling. We report on the net ecosystem <span class="hlt">exchange</span> of carbon dioxide (NEE) of a semidesert grassland through a severe drought which drove succession from native bunchgrasses to forbs and to eventual dominance by an exotic bunchgrass. We monitored NEE and energy fluxes using eddy covariance coupled with meteorological and soil moisture variables for 6 years at a grassland site in southeastern Arizona, USA. Seasonal NEE typically showed a springtime carbon uptake after winter-spring periods of average rainfall followed by much stronger sink activity during the summer rainy season. The two severe drought years (2004 and 2005) resulted in a net release of carbon dioxide (25 g C m-2) and widespread mortality of native perennial bunchgrasses. Above average summer rains in 2006 alleviated drought conditions, resulting in a large flush of broad-leaved forbs and negative total NEE (-55 g C m-2 year-1). Starting in 2007 and continuing through 2009, the ecosystem became increasingly dominated by the exotic grass, Eragrostis lehmanniana, and was a net carbon sink (-47 to -98 g C m-2 year-1) but with distinct annual patterns in NEE. Rainfall mediated by soils was the key driver to water and carbon fluxes. Seasonal respiration and photosynthesis were strongly dependent on precipitation, but photosynthesis was more sensitive to rainfall variation. Respiration normalized by evapotranspiration showed no interannual variation, while normalized gross ecosystem production (i.e., water use efficiency) was low during drought years and then increased as the rains returned and the E. lehmanniana invasion progressed. Thus, when dry summer conditions returned in 2009, the potential for ecosystem carbon accumulation was increased and the ecosystem remained a net sink unlike similar dry years when</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26416158','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26416158"><span id="translatedtitle">Mitochondrial ADP/ATP <span class="hlt">exchange</span> inhibition: a novel off-target mechanism underlying ibipinabant-<span class="hlt">induced</span> myotoxicity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schirris, Tom J J; Ritschel, Tina; Herma Renkema, G; Willems, Peter H G M; Smeitink, Jan A M; Russel, Frans G M</p> <p>2015-01-01</p> <p>Cannabinoid receptor 1 (CB1R) antagonists appear to be promising drugs for the treatment of obesity, however, serious side effects have hampered their clinical application. Rimonabant, the first in class CB1R antagonist, was withdrawn from the market because of psychiatric side effects. This has led to the search for more peripherally restricted CB1R antagonists, one of which is ibipinabant. However, this 3,4-diarylpyrazoline derivative showed muscle toxicity in a pre-clinical dog study with mitochondrial dysfunction. Here, we studied the molecular mechanism by which ibipinabant <span class="hlt">induces</span> mitochondrial toxicity. We observed a strong cytotoxic potency of ibipinabant in C2C12 myoblasts. Functional characterization of mitochondria revealed increased cellular reactive oxygen species generation and a decreased ATP production capacity, without effects on the catalytic activities of mitochondrial enzyme complexes I-V or the complex specific-driven oxygen consumption. Using in silico off-target prediction modelling, combined with in vitro validation in isolated mitochondria and mitoplasts, we identified adenine nucleotide translocase (ANT)-dependent mitochondrial ADP/ATP <span class="hlt">exchange</span> as a novel molecular mechanism underlying ibipinabant-<span class="hlt">induced</span> toxicity. Minor structural modification of ibipinabant could abolish ANT inhibition leading to a decreased cytotoxic potency, as observed with the ibipinabant derivative CB23. Our results will be instrumental in the development of new types of safer CB1R antagonists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25830299','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25830299"><span id="translatedtitle">Na+/H+ <span class="hlt">exchanger</span> isoform 1 <span class="hlt">induced</span> cardiomyocyte hypertrophy involves activation of p90 ribosomal s6 kinase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaballah, Maiy; Mohamed, Iman A; Alemrayat, Bayan; Al-Sulaiti, Fatima; Mlih, Mohamed; Mraiche, Fatima</p> <p>2015-01-01</p> <p>Studies using pharmacological and genetic approaches have shown that increased activity/expression of the Na+/H+ <span class="hlt">exchanger</span> isoform 1 (NHE1) play a critical role in the pathogenesis of cardiac hypertrophy. Despite the importance of NHE1 in cardiac hypertrophy, severe cerebrovascular side effects were associated with the use of NHE1 inhibitors when administered to patients with myocardial infarctions. p90 ribosomal S6 Kinase (RSK), a downstream regulator of the mitogen-activated protein kinase pathway, has also been implicated in cardiac hypertrophy. We hypothesized that RSK plays a role in the NHE1 <span class="hlt">induced</span> cardiomyocyte hypertrophic response. Infection of H9c2 cardiomyoblasts with the active form of the NHE1 adenovirus <span class="hlt">induced</span> hypertrophy and was associated with an increase in the phosphorylation of RSK (P<0.05). Parameters of hypertrophy such as cell area, protein content and atrial natriuretic mRNA expression were significantly reduced in H9c2 cardiomyoblasts infected with active NHE1 in the presence of dominant negative RSK (DN-RSK) (P<0.05). These results confirm that NHE1 lies upstream of RSK. Increased phosphorylation and activation of GATA4 at Ser261 was correlated with increased RSK phosphorylation. This increase was reversed upon inhibition of RSK or NHE1. These findings demonstrate for the first time that the NHE1 mediated hypertrophy is accounted for by increased activation and phosphorylation of RSK, which subsequently increased the phosphorylation of GATA4; eventually activating fetal gene transcriptional machinery. PMID:25830299</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4586513','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4586513"><span id="translatedtitle">Mitochondrial ADP/ATP <span class="hlt">exchange</span> inhibition: a novel off-target mechanism underlying ibipinabant-<span class="hlt">induced</span> myotoxicity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schirris, Tom J. J.; Ritschel, Tina; Herma Renkema, G.; Willems, Peter H. G. M.; Smeitink, Jan A. M.; Russel, Frans G. M.</p> <p>2015-01-01</p> <p>Cannabinoid receptor 1 (CB1R) antagonists appear to be promising drugs for the treatment of obesity, however, serious side effects have hampered their clinical application. Rimonabant, the first in class CB1R antagonist, was withdrawn from the market because of psychiatric side effects. This has led to the search for more peripherally restricted CB1R antagonists, one of which is ibipinabant. However, this 3,4-diarylpyrazoline derivative showed muscle toxicity in a pre-clinical dog study with mitochondrial dysfunction. Here, we studied the molecular mechanism by which ibipinabant <span class="hlt">induces</span> mitochondrial toxicity. We observed a strong cytotoxic potency of ibipinabant in C2C12 myoblasts. Functional characterization of mitochondria revealed increased cellular reactive oxygen species generation and a decreased ATP production capacity, without effects on the catalytic activities of mitochondrial enzyme complexes I–V or the complex specific-driven oxygen consumption. Using in silico off-target prediction modelling, combined with in vitro validation in isolated mitochondria and mitoplasts, we identified adenine nucleotide translocase (ANT)-dependent mitochondrial ADP/ATP <span class="hlt">exchange</span> as a novel molecular mechanism underlying ibipinabant-<span class="hlt">induced</span> toxicity. Minor structural modification of ibipinabant could abolish ANT inhibition leading to a decreased cytotoxic potency, as observed with the ibipinabant derivative CB23. Our results will be instrumental in the development of new types of safer CB1R antagonists. PMID:26416158</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25139235','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25139235"><span id="translatedtitle">WRNIP1 functions upstream of DNA polymerase η in the UV-<span class="hlt">induced</span> DNA damage response.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoshimura, Akari; Kobayashi, Yume; Tada, Shusuke; Seki, Masayuki; Enomoto, Takemi</p> <p>2014-09-12</p> <p>WRNIP1 (WRN-interacting protein 1) was first identified as a factor that interacts with WRN, the protein that is defective in Werner syndrome (WS). WRNIP1 associates with DNA polymerase η (Polη), but the biological significance of this interaction remains unknown. In this study, we analyzed the functional interaction between WRNIP1 and Polη by generating knockouts of both genes in DT40 chicken cells. Disruption of WRNIP1 in Polη-disrupted (POLH(-/-)) cells suppressed the phenotypes associated with the loss of Polη: sensitivity to ultraviolet light (UV), delayed repair of cyclobutane pyrimidine dimers (CPD), elevated frequency of mutation, elevated levels of UV-<span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE), and reduced rate of fork progression after UV irradiation. These results suggest that WRNIP1 functions upstream of Polη in the response to UV irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8287839','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8287839"><span id="translatedtitle">Genotoxicity to human cells <span class="hlt">induced</span> by air particulates isolated during the Kuwait oil fires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kelsey, K T; Xia, F; Bodell, W J; Spengler, J D; Christiani, D C; Dockery, D W; Liber, H L</p> <p>1994-01-01</p> <p>In an effort to examine the potential of exposure to soot from the 1991 oil fires in the Kuwait desert for <span class="hlt">inducing</span> genetic effects we studied the in vitro genotoxicity of this material. Air particulates isolated near the Kuwait oil fires were studied using three assays. Dose-dependent increases were observed for both sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in human peripheral blood lymphocytes and mutation at the hprt locus in the metabolically competent human lymphoblast cell line AHH-1. Similar magnitudes of response were seen using these two assays when testing a standard air particulate sample which had been isolated from the Washington, DC, area. Using the 32P-postlabeling assay, no increase in DNA adduct formation was observed in AHH-1 cells treated with particulates isolated from sampling in Kuwait.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...713105W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...713105W"><span id="translatedtitle">Excess titanium dioxide nanoparticles on the cell surface <span class="hlt">induce</span> cytotoxicity by hindering ion <span class="hlt">exchange</span> and disrupting exocytosis processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yanli; Yao, Chenjie; Li, Chenchen; Ding, Lin; Liu, Jian; Dong, Peng; Fang, Haiping; Lei, Zhendong; Shi, Guosheng; Wu, Minghong</p> <p>2015-07-01</p> <p>To date, considerable effort has been devoted to determine the potential toxicity of nanoparticles to cells and organisms. However, determining the mechanism of cytotoxicity <span class="hlt">induced</span> by different types of nanoparticles remains challenging. Herein, typically low toxicity nanomaterials were used as a model to investigate the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials. We studied the effect of nano-TiO2, nano-Al2O3 and nano-SiO2 deposition films on the ion concentration on a cell-free system simulating the cell membrane. The results showed that the ion concentration of K+, Ca2+, Na+, Mg2+ and SO42- decreased significantly following filtration of the prepared deposition films. More specifically, at a high nano-TiO2 concentration (200 mg L-1) and a long nano-TiO2 deposition time (48 h), the concentration of Na+ decreased from 2958.01 to 2775.72, 2749.86, 2757.36, and 2719.82 mg L-1, respectively, for the four types of nano-TiO2 studied. Likewise, the concentration of SO42- decreased from 38.83 to 35.00, 35.80, 35.40, and 35.27 mg L-1, respectively. The other two kinds of typical low toxicity nanomaterials (nano-Al2O3 and nano-SiO2) have a similar impact on the ion concentration change trend. Adsorption of ions on nanoparticles and the hydrated shell around the ions strongly hindered the ions through the nanoparticle films. The endocytosed nanoparticles could be released from the cells without <span class="hlt">inducing</span> cytotoxicity. Hindering the ion <span class="hlt">exchange</span> and disrupting the exocytosis process are the main factors that <span class="hlt">induce</span> cytotoxicity in the presence of excess nano-TiO2 on the cell surface. The current findings may offer a universal principle for understanding the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials.To date, considerable effort has been devoted to determine the potential toxicity of nanoparticles to cells and organisms. However, determining the mechanism of cytotoxicity <span class="hlt">induced</span> by different types of nanoparticles remains challenging</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.B22A0744V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.B22A0744V"><span id="translatedtitle">The Effect of Experimentally <span class="hlt">Induced</span> Root Mortality on Trace Gas <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varner, R. K.; Keller, M.; Robertson, J. R.; Dias, J. D.; Silva, H.; Crill, P. M.; McGroddy, M.; Silver, W. L.</p> <p>2002-12-01</p> <p>Soil-atmosphere <span class="hlt">exchange</span> of carbon dioxide (CO2), nitric oxide (NO), nitrous oxide (N2O) and methane (CH4) was measured following a root exclusion experiment in the Tapajos National Forest near Santarem, Para, Brazil. The sampling period (June 4 - August 14, 2000) coincided with the beginning of the dry season. The experiment was set up as a randomized complete block design with 5 pairs of 2.5 x 2.5 m plots in both sand and clay soils. Trenches were dug around one plot in each pair for screen installation. Trace gas fluxes were measured weekly for ten weeks following the trenching. Duplicate flux measurements were made for each of the trenched and non-trenched plots. Enclosures made of 0.25 m diameter PVC pipe were placed on a base imbedded in the soil. Dynamic measurements using a portable backpack system equipped with an NO2 chemiluminescent detector for NO and an infrared gas analyzer for CO2 were completed in the field. CH4 and N2O fluxes were measured through a static enclosure method. Syringe samples of the enclosure headspace were analyzed by GC-FID (CH4) and ECD (N2O) the following day. Daily average fluxes ranged between -0.01 and 60.3 ng-N cm-2 hr-1 for N2O. NO fluxes ranged between 0.58 and 8.74 ng-N cm-2 hr-1. CH4 fluxes varied between net consumption and production from -1.73 to 0.912 mg m-2 d-1. Soil respiration ranged from 1.34 to 5.12 umoles CO2 m-2 s-1. Significant differences were seen between trenched and non-trenched plots in both clay and sand soils for N2O emissions only. Hourly field standardization of the NO2 chemiluminescent analyzer resulted in lower variability than the traditional method of standardization which is completed at the beginning and end of the measurement day. Frequent field standardization of the analyzer is necessary to reduce measurement error due to intra-day variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26278684','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26278684"><span id="translatedtitle">Chiral template <span class="hlt">induced</span> homochiral MOFs built from achiral components: SHG enhancement and enantioselective sensing of chiral alkamines by ion-<span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Han, Yun-Hu; Liu, Yue-Cheng; Xing, Xiu-Shuang; Tian, Chong-Bin; Lin, Ping; Du, Shao-Wu</p> <p>2015-10-01</p> <p>A pair of chiral template <span class="hlt">induced</span> anionic homochiral frameworks constructed from achiral components has been synthesized. Ion-<span class="hlt">exchange</span> of counter cations with polar or chiral organic cations enhances the SHG efficiency of the frameworks. The enantioselective sensing of chiral alkamines can be achieved by the SHG response.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..287M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..287M"><span id="translatedtitle">Eddy <span class="hlt">induced</span> Temperature <span class="hlt">Exchange</span> between Subpolar and Subtropical Gyre - a comparison of observations and model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, Vasco; Kieke, Dagmar; Myers, Paul G.; Mertens, Christian; Pennelly, Clark</p> <p>2016-04-01</p> <p>Eddies in the subpolar North Atlantic play an important role for temperature, freshwater and volume fluxes across the front between the subpolar and subtropical gyre and thus influence the hydrography and dynamics in the Subarctic and Arctic realm. Here, we ask where and how eddy <span class="hlt">induced</span> mixing takes place, if there are localized hotspots of mixing and what are the main pathways of eddies between the gyres. We analyze the eddy field in more than 20 years of satellite altimetry observations with 1/4° horizontal resolution, using a geometry based eddy detection and tracking algorithm. To estimate the respective temperature flux of individual eddies, the eddy surface area and translation speed from the eddy detection and tracking algorithm are combined with anomalies of a real-time global sea surface temperature (SST) analysis. In order to analyze the effect of resolution on the results, we compare the findings in the observations to model experiments with the NEMO ocean model using two different set-ups: (1) ANHA4 with 1/4° horizontal resolution and (2) ANHA4 with an nested 1/12° horizontal resolution encompassing the subpolar North Atlantic. For the analysis of the temperature flux, we focus on the zonal section at 47°N as it represents a good approximation for the gyre boundary. Additionally, we have ship based velocity observations from 10 cruises between 2003 and 2014 available for this section, that allow us to compare the observed eddy temperature flux to the mean circulation across the section. In both observations and model, the shear region between Western Boundary Current, North Atlantic Current and the recirculation cell in the Newfoundland Basin is the most active region regarding eddy activity and eddy <span class="hlt">induced</span> temperature flux across 47°N.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19823170','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19823170"><span id="translatedtitle">Compensatory role of <span class="hlt">inducible</span> annexin A2 for impaired biliary epithelial anion-<span class="hlt">exchange</span> activity of inflammatory cholangiopathy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kido, Osamu; Fukushima, Koji; Ueno, Yoshiyuki; Inoue, Jun; Jefferson, Douglas M; Shimosegawa, Tooru</p> <p>2009-12-01</p> <p>The peribiliary inflammation of cholangiopathy affects the physiological properties of biliary epithelial cells (cholangiocyte), including bicarbonate-rich ductular secretion. We revealed the upregulation of annexin A2 (ANXA2) in cholangiocytes in primary biliary cirrhosis (PBC) by a proteomics approach and evaluated its physiological significance. Global protein expression profiles of a normal human cholangiocyte line (H69) in response to interferon-gamma (IFNgamma) were obtained by two-dimensional electrophoresis followed by MALDI-TOF-MS. Histological expression patterns of the identified molecules in PBC liver were confirmed by immunostaining. H69 cells stably transfected with doxycyclin-<span class="hlt">inducible</span> ANXA2 were subjected to physiological evaluation. Recovery of the intracellular pH after acute alkalinization was measured consecutively by a pH indicator with a specific inhibitor of anion <span class="hlt">exchanger</span> (AE), 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). Protein kinase-C (PKC) activation was measured by PepTag Assay and immunoblotting. Twenty spots that included ANXA2 were identified as IFNgamma-responsive molecules. Cholangiocytes of PBC liver were decorated by the unique membranous overexpression of ANXA2. Apical ANXA2 of small ducts of PBC was directly correlated with the clinical cholestatic markers and transaminases. Controlled induction of ANXA2 resulted in significant increase of the DIDS-inhibitory fraction of AE activity of H69, which was accompanied by modulation of PKC activity. We, therefore, identified ANXA2 as an IFNgamma-<span class="hlt">inducible</span> gene in cholangiocytes that could serve as a potential histological marker of inflammatory cholangiopathy, including PBC. We conclude that <span class="hlt">inducible</span> ANXA2 expression in cholangiocytes may play a compensatory role for the impaired AE activity of cholangiocytes in PBC in terms of bicarbonate-rich ductular secretion and bile formation through modulation of the PKC activity. PMID:19823170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510840','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510840"><span id="translatedtitle">Oxygen-limited thermal tolerance is seen in a plastron-breathing insect and can be <span class="hlt">induced</span> in a bimodal gas <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Verberk, Wilco C. E. P.; Bilton, David T.</p> <p>2015-01-01</p> <p>ABSTRACT Thermal tolerance has been hypothesized to result from a mismatch between oxygen supply and demand. However, the generality of this hypothesis has been challenged by studies on various animal groups, including air-breathing adult insects. Recently, comparisons across taxa have suggested that differences in gas <span class="hlt">exchange</span> mechanisms could reconcile the discrepancies found in previous studies. Here, we test this suggestion by comparing the behaviour of related insect taxa with different gas <span class="hlt">exchange</span> mechanisms, with and without access to air. We demonstrate oxygen-limited thermal tolerance in air-breathing adults of the plastron-<span class="hlt">exchanging</span> water bug Aphelocheirus aestivalis. Ilyocoris cimicoides, a related, bimodal gas <span class="hlt">exchanger</span>, did not exhibit such oxygen-limited thermal tolerance and relied increasingly on aerial gas <span class="hlt">exchange</span> with warming. Intriguingly, however, when denied access to air, oxygen-limited thermal tolerance could also be <span class="hlt">induced</span> in this species. Patterns in oxygen-limited thermal tolerance were found to be consistent across life-history stages in these insects, with nymphs employing the same gas <span class="hlt">exchange</span> mechanisms as adults. These results advance our understanding of oxygen limitation at high temperatures; differences in the degree of respiratory control appear to modulate the importance of oxygen in setting tolerance limits. PMID:25964420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20130010162&hterms=Breccia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBreccia','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20130010162&hterms=Breccia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBreccia"><span id="translatedtitle">The Galim LL/EH Polymict Breccia: Evidence for Impact-<span class="hlt">Induced</span> <span class="hlt">Exchange</span> Between Reduced and Oxidized Meteoritic Material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubin, Alan E.</p> <p>1997-01-01</p> <p>Galim is a polymict breccia consisting of a heavily shocked (shock stage S6) LL6 chondrite, Galim (a), and an impact-melted EH chondrite, Galim (b). Relict chondrules in Galim (b) served as nucleation sites for euhedral enstatite grains crystallizing from the impact melt. Many of the reduced phases typical of EH chondrites (e.g., Si-bearing metallic Fe-Ni; Ti-bearing troilite) are absent. Galim (b) was probably shock-melted while in contact with a more oxidized source, namely, Galim (a); during this event, Si was oxidized from the metal and Ti was oxidized from troilite. Galim (a) contains shock veins and recrystallized, unzoned olivine. The absence of evidence for reduction in Galim (a) may indicate that the amount of LL material greatly exceeded that of EH material; shock metamorphism may have taken place on the LL parent body. Shock-<span class="hlt">induced</span> redox reactions such as those inferred for the Galim breccia appear to be restricted mainly to asteroids because the low-end tail of their relative-velocity distribution permits mixing of intact disparate materials (including accretion of projectiles of different oxidation states), whereas the peak of the distribution leads to high equilibration shock pressures (allowing impact-<span class="hlt">induced</span> <span class="hlt">exchange</span> between previously accreted, disequilibrated materials). Galim probably formed by a two-stage process: (I) accretion to the LL parent body of an intact EH projectile at low relative velocities, and (2) shock metamorphism of the assemblage by the subsequent impact of another projectile at significantly higher relative velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JAP....58.4521C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JAP....58.4521C"><span id="translatedtitle">Strain and surface damage <span class="hlt">induced</span> by proton <span class="hlt">exchange</span> in Y-cut LiNbO3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campari, A.; Ferrari, C.; Mazzi, G.; Summonte, C.; Al-Shukri, S. M.; Dawar, A.; De La Rue, R. M.; Nutt, A. C. G.</p> <p>1985-12-01</p> <p>When Y-cut LiNbO3 substrates are proton <span class="hlt">exchanged</span> in pure benzoic acid to fabricate optical waveguides, they suffer surface damage, and a consequent degradation in optical properties. This effect is mainly produced by a remarkably large strain in the <span class="hlt">exchanged</span> layer in a direction normal to the surface. This strain leads to a large number of cracks and to the peeling off of the <span class="hlt">exchanged</span> layer itself. This paper presents a probable explanation of the mechanism involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3441363','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3441363"><span id="translatedtitle">Inhibitor of neuronal nitric oxide synthase improves gas <span class="hlt">exchange</span> in ventilator-<span class="hlt">induced</span> lung injury after pneumonectomy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Mechanical ventilation with high tidal volumes may cause ventilator-<span class="hlt">induced</span> lung injury (VILI) and enhanced generation of nitric oxide (NO). We demonstrated in sheep that pneumonectomy followed by injurious ventilation promotes pulmonary edema. We wished both to test the hypothesis that neuronal NOS (nNOS), which is distributed in airway epithelial and neuronal tissues, could be involved in the pathogenesis of VILI and we also aimed at investigating the influence of an inhibitor of nNOS on the course of VILI after pneumonectomy. Methods Anesthetized sheep underwent right pneumonectomy, mechanical ventilation with tidal volumes (VT) of 6 mL/kg and FiO2 0.5, and were subsequently randomized to a protectively ventilated group (PROTV; n = 8) keeping VT and FiO2 unchanged, respiratory rate (RR) 25 inflations/min and PEEP 4 cm H2O for the following 8 hrs; an injuriously ventilated group with VT of 12 mL/kg, zero end-expiratory pressure, and FiO2 and RR unchanged (INJV; n = 8) and a group, which additionally received the inhibitor of nNOS, 7-nitroindazole (NI) 1.0 mg/kg/h intravenously from 2 hours after the commencement of injurious ventilation (INJV + NI; n = 8). We assessed respiratory, hemodynamic and volumetric variables, including both the extravascular lung water index (EVLWI) and the pulmonary vascular permeability index (PVPI). We measured plasma nitrite/nitrate (NOx) levels and examined lung biopsies for lung injury score (LIS). Results Both the injuriously ventilated groups demonstrated a 2–3-fold rise in EVLWI and PVPI, with no significant effects of NI. In the INJV group, gas <span class="hlt">exchange</span> deteriorated in parallel with emerging respiratory acidosis, but administration of NI antagonized the derangement of oxygenation and the respiratory acidosis significantly. NOx displayed no significant changes and NI exerted no significant effect on LIS in the INJV group. Conclusion Inhibition of nNOS improved gas <span class="hlt">exchange</span>, but did not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19022230','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19022230"><span id="translatedtitle">Effects of KR-33028, a novel Na+/H+ <span class="hlt">exchanger</span>-1 inhibitor, on glutamate-<span class="hlt">induced</span> neuronal cell death and ischemia-<span class="hlt">induced</span> cerebral infarct.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Bo Kyung; Lee, Dong Ha; Park, Sok; Park, Sung Lyea; Yoon, Jae-Seok; Lee, Min Goo; Lee, Sunkyung; Yi, Kyu Yang; Yoo, Sung Eun; Lee, Kyung Hee; Kim, You-Sun; Lee, Soo Hwan; Baik, Eun Joo; Moon, Chang-Hyun; Jung, Yi-Sook</p> <p>2009-01-12</p> <p>We investigated the effects of a novel Na(+)/H(+) <span class="hlt">exchanger</span>-1 (NHE-1) inhibitor KR-33028 on glutamate excitotoxicity in cultured neuron cells in vitro and cerebral infarct in vivo by comparing its potency with that of zoniporide, a well-known, highly potent NHE-1 inhibitor. KR-33028 inhibited NHE-1 activation in a concentration-dependent manner (IC(50)=2.2 nM), with 18-fold greater potency than that of zoniporide (IC(50)=40.7 nM). KR-33028 significantly attenuated glutamate-<span class="hlt">induced</span> LDH release with approximately 100 times lower EC(25) than that of zoniporide in cortical neurons in vitro (EC(25) of 0.007 and 0.81 microM, respectively), suggesting its 100-fold greater potency than zoniporide in producing anti-necrotic effect. In addition, the EC(50) of KR-33028 for anti-apoptotic effect was 100 times lower than that of zoniporide shown by TUNEL positivity (0.005 and 0.62 microM, respectively) and caspase-3 activity (0.01 and 2.64 microM, respectively). Furthermore, the EC(50) value of KR-33028 against glutamate-<span class="hlt">induced</span> intracellular Ca(2+) overload was also 100 times lower than that of zoniporide (EC(50) of 0.004 and 0.65 microM, respectively). In the in vivo cerebral infarct model (60 min middle cerebral artery occlusion followed by 24 h reperfusion), KR-33028 reduced infarct size in a dose-dependent manner. Its ED(25) value, however, was quite similar to that of zoniporide (ED(25) of 0.072 and 0.097 mg/kg, respectively). Hence these results suggest that the novel NHE-1 inhibitor, KR-33028, could be an efficient therapeutic tool to protect neuronal cells against ischemic injury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1258605-electric-field-induced-reversible-magnetization-switching-through-tuning-interfacial-exchange-bias-along-magnetic-easy-axis-multiferroic-laminates','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1258605-electric-field-induced-reversible-magnetization-switching-through-tuning-interfacial-exchange-bias-along-magnetic-easy-axis-multiferroic-laminates"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; et al</p> <p>2015-11-18</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shiftedmore » by up to |ΔHex|/Hex=8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |ΔHex|/Hc=67.5~125% in NiFe/FeMn/glass/PZN-PT and 30~38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Lastly, electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4649679','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4649679"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; Liu, Ming</p> <p>2015-01-01</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shifted by up to |∆Hex|/Hex = 8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |∆Hex|/Hc = 67.5 ~ 125% in NiFe/FeMn/glass/PZN-PT and 30 ~ 38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies. PMID:26576658</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......126K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......126K"><span id="translatedtitle">Targets for, and consequences of, radiation-<span class="hlt">induced</span> chromosomal instability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaplan, Mark Isaac</p> <p></p> <p>Chromosomal instability has been demonstrated in a human- hamster hybrid cell line, GM10115, after exposure to x- rays. Chromosomal instability in these cells is characterized by the appearance of novel chromosomal rearrangements multiple generations after exposure to ionizing radiation. To identify the cellular target(s) for radiation-<span class="hlt">induced</span> chromosomal instability, cells were treated with 125I-labeled compounds. Labeling cells with 125I-iododeoxyuridine, which caused radiation damage to the DNA and associated nuclear structures, did <span class="hlt">induce</span> chromosomal instability. While cell killing and first-division chromosomal rearrangements increased with increasing numbers of 125I decays, the frequency of chromosomal instability was independent of dose. Incorporation of an 125I-labeled protein, 125I-succinyl- concanavalin A, into either the plasma membrane or the cytoplasm, failed to elicit chromosomal instability. These results show that radiation damage to the nucleus, and not to extranuclear regions, contributes to the induction of chromosomal instability. To determine the role of DNA strand breaks as a molecular lesion responsible for initiating chromosomal instability, cells were treated with a variety of DNA strand breaking agents. Agents capable of producing complex DNA double strand breaks, including X-rays, Neocarzinostatin and bleomycin, were able to <span class="hlt">induce</span> chromosomal instability. In contrast, double strand breaks produced by restriction endonucleases as well as DNA strand breaks produced by hydrogen peroxide failed to <span class="hlt">induce</span> chromosomal instability. This demonstrates that the type of DNA breakage is important in the eventual manifestation of chromosomal instability. In order to understand the relationship between chromosomal instability and other end points of genomic instability, chromosomally stable and unstable clones were analyzed for sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span>, delayed reproductive cell death, delayed mutation, mismatch repair and delayed gene amplification</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApSS..371...67M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApSS..371...67M"><span id="translatedtitle">Sulfidation behavior of ZnFe2O4 roasted with pyrite: Sulfur <span class="hlt">inducing</span> and sulfur-oxygen interface <span class="hlt">exchange</span> mechanism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Min, Xiaobo; Zhou, Bosheng; Ke, Yong; Chai, Liyuan; Xue, Ke; Zhang, Chun; Zhao, Zongwen; Shen, Chen</p> <p>2016-05-01</p> <p>The sulfidation roasting behavior was analyzed in detail to reveal the reaction mechanism. Information about the sulfidation reaction, including phase transformation, ionic migration behavior and morphological change, were obtained by XRD, 57Fe Mossbauer spectroscopy, XPS and SEM analysis. The results showed that the sulfidation of zinc ferrite is a process of sulfur <span class="hlt">inducing</span> and sulfur-oxygen interface <span class="hlt">exchange</span>. This process can be divided into six stages: decomposition of FeS2, formation of the oxygen-deficient environment, migration of O2- <span class="hlt">induced</span> by S2(g), formation of ZnFe2O4-δ, migration of Fe2+ accompanied by the precipitation of ZnO, and the sulfur-oxygen interface <span class="hlt">exchange</span> reaction. The sulfidation products were zinc blende, wurtzite, magnetite and a fraction of zinc-bearing magnetite. These findings can provide theoretical support for controlling the process during which the recovery of Zn and Fe is achieved through the combined flotation-magnetic separation process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23200805','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23200805"><span id="translatedtitle">Assessment of nicotine-<span class="hlt">induced</span> DNA damage in a genotoxicological test battery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ginzkey, Christian; Friehs, Gudrun; Koehler, Christian; Hackenberg, Stephan; Hagen, Rudolf; Kleinsasser, Norbert H</p> <p>2013-02-18</p> <p>The role of the tobacco-alkaloid nicotine in tumour biology is widely discussed in the literature. Due to a strong capacity to <span class="hlt">induce</span> angiogenesis, a pro-mutagenic potential in non-tumour and cancer cells, and a pro- and anti-apoptotic influence, nicotine seems to promote the growth of established tumours. However, results indicating DNA damage and genetic instability associated with nicotine have been contradictory thus far. A variety of markers and endpoints of genotoxicity are required to characterize the genotoxic potential of nicotine. Induction of DNA single- and double-strand breaks, the formation of micronuclei, and the induction of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> and chromosome aberrations represent possible genotoxicological endpoints at different cellular levels. Human lymphocytes were exposed to nicotine concentrations between 1μM and 1mM for 24h in vitro. The comet assay, the cytokinesis-block micronucleus test, the chromosome aberration (CA) test, and the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) test were then applied. Viability and apoptosis were measured by flow cytometry in combination with the annexin V-propidium iodide staining test. In this test setting, no enhanced DNA migration was measured by the comet assay. An increase in the micronucleus frequency was detected at a concentration of 100μM nicotine without affecting the frequency of apoptotic cells. A distinct genotoxic effect was determined by the CA test and the SCE test, with a significant increase in CA and SCE at a concentration of 1μM. In the annexin V test, nicotine did not influence the proportion of apoptotic or necrotic cells. The current data indicating the induction of CA by nicotine underscore the necessity of ongoing investigations on the potential of nicotine to initiate mutagenesis and tumour promotion. Taking into account the physiological nicotine plasma levels in smokers or in nicotine-replacement therapy, particularly the long-term use of nicotine should be critically discussed. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26724742','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26724742"><span id="translatedtitle">Treadmill exercise ameliorates ischemia-<span class="hlt">induced</span> brain edema while suppressing Na⁺/H⁺ <span class="hlt">exchanger</span> 1 expression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nishioka, Ryutaro; Sugimoto, Kana; Aono, Hitomi; Mise, Ayano; Choudhury, Mohammed E; Miyanishi, Kazuya; Islam, Afsana; Fujita, Takahiro; Takeda, Haruna; Takahashi, Hisaaki; Yano, Hajime; Tanaka, Junya</p> <p>2016-03-01</p> <p>Exercise may be one of the most effective and sound therapies for stroke; however, the mechanisms underlying the curative effects remain unclear. In this study, the effects of forced treadmill exercise with electric shock on ischemic brain edema were investigated. Wistar rats were subjected to transient (90 min) middle cerebral artery occlusion (tMCAO). Eighty nine rats with substantially large ischemic lesions were evaluated using magnetic resonance imaging (MRI) and were randomly assigned to exercise and non-exercise groups. The rats were forced to run at 4-6m/s for 10 min/day on days 2, 3 and 4. Brain edema was measured on day 5 by MRI, histochemical staining of brain sections and tissue water content determination (n=7, each experiment). Motor function in some rats was examined on day 30 (n=6). Exercise reduced brain edema (P<0.05-0.001, varied by the methods) and ameliorated motor function (P<0.05). The anti-glucocorticoid mifepristone or the anti-mineralocorticoid spironolactone abolished these effects, but orally administered corticosterone mimicked the ameliorating effects of exercise. Exercise prevented the ischemia-<span class="hlt">induced</span> expression of mRNA encoding aquaporin 4 (AQP4) and Na(+)/H(+) <span class="hlt">exchangers</span> (NHEs) (n=5 or 7, P<0.01). Microglia and NG2 glia expressed NHE1 in the peri-ischemic region of rat brains and also in mixed glial cultures. Corticosterone at ~10nM reduced NHE1 and AQP4 expression in mixed glial and pure microglial cultures. Dexamethasone and aldosterone at 10nM did not significantly alter NHE1 and AQP4 expression. Exposure to a NHE inhibitor caused shrinkage of microglial cells. These results suggest that the stressful short-period and slow-paced treadmill exercise suppressed NHE1 and AQP4 expression resulting in the amelioration of brain edema at least partly via the moderate increase in plasma corticosterone levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26716266','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26716266"><span id="translatedtitle">Preparation of a Proton-<span class="hlt">Exchange</span> Me mbrane with -SO3H Group Based on Polyethylene and Poly(vinylidene fluoride) Film by Radiation-<span class="hlt">Induced</span> Graft Polymerization for Proton-<span class="hlt">Exchange</span> Fuel Cell.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Sang-Kyum; Lee, Yong-Sang; Koo, Kee-Kahb; Kim, Sang-Ho; Choi, Seong-Ho</p> <p>2015-09-01</p> <p>This paper reports the preparation of a proton-<span class="hlt">exchange</span> membrane (PEM) with sulfonic acid (-SO3H) groups based on polyethylene (PE) films and poly(vinylidene fluoride) (PVdF) films by the radiation-<span class="hlt">induced</span> graft polymerization (RIGP) of sodium styrene sulfonate (NaSS) in the presence of the polymerizable access agents, such as acrylic acid and pyrollidone in a methanol solution. A PEM with -SO3H based on PE and PVdF films were confirmed by ATR, XPS and contact angle measurements. The water uptake (%), graft yield (%), ion-<span class="hlt">exchange</span> content (mmol/g), and proton conductivity (S/cm), as well as the current density (mA/cm2), and power density (mW/cm) for PEM with -SO3H groups prepared by RIGP were evaluated. The PEM prepared with the -SO3H groups based on PE and PVdF films can be used as a proton-<span class="hlt">exchange</span> fuel cell membrane. PMID:26716266</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26716266','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26716266"><span id="translatedtitle">Preparation of a Proton-<span class="hlt">Exchange</span> Me mbrane with -SO3H Group Based on Polyethylene and Poly(vinylidene fluoride) Film by Radiation-<span class="hlt">Induced</span> Graft Polymerization for Proton-<span class="hlt">Exchange</span> Fuel Cell.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Sang-Kyum; Lee, Yong-Sang; Koo, Kee-Kahb; Kim, Sang-Ho; Choi, Seong-Ho</p> <p>2015-09-01</p> <p>This paper reports the preparation of a proton-<span class="hlt">exchange</span> membrane (PEM) with sulfonic acid (-SO3H) groups based on polyethylene (PE) films and poly(vinylidene fluoride) (PVdF) films by the radiation-<span class="hlt">induced</span> graft polymerization (RIGP) of sodium styrene sulfonate (NaSS) in the presence of the polymerizable access agents, such as acrylic acid and pyrollidone in a methanol solution. A PEM with -SO3H based on PE and PVdF films were confirmed by ATR, XPS and contact angle measurements. The water uptake (%), graft yield (%), ion-<span class="hlt">exchange</span> content (mmol/g), and proton conductivity (S/cm), as well as the current density (mA/cm2), and power density (mW/cm) for PEM with -SO3H groups prepared by RIGP were evaluated. The PEM prepared with the -SO3H groups based on PE and PVdF films can be used as a proton-<span class="hlt">exchange</span> fuel cell membrane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12379012','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12379012"><span id="translatedtitle"><span class="hlt">Chromatid</span> gaps as a marker of mutagenic effect of environmental pollution in commensal and wild rodents of the Ural mountains.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gileva, E A</p> <p>2002-01-01</p> <p>It was supposed earlier that achromatic gaps could be used as markers of mutagenic effect of environmental pollution, especially under weaker clastogenic influences. The frequencies of true chromosome aberrations and those of <span class="hlt">chromatid</span> gaps were estimated in house mice and common voles from Uralian localities with various mutagenic potential of environment. Gaps and breaks were distinguished according to the CBIS system. In several localities, rodents displayed highly significant increase of the rates of cells with chromosome aberrations and with gaps as compared to the baseline values; only in the common vole, the P level for the gap increase was 0.056. The mean gap rate was correlated significantly with that of chromosome aberrations, not only with <span class="hlt">chromatid</span> breaks, but with the aberrations of other types, too. This parameter appears not to be more sensitive indicator of environmental mutagens than true chromosome mutations, when mutagenic impact is not very powerful, as it was in the localities investigated. The house mouse can be recommended as an effective test species for ecogenetic monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25210500','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25210500"><span id="translatedtitle">Selective <span class="hlt">chromatid</span> segregation mechanism invoked for the human congenital mirror hand movement disorder development by RAD51 mutations: a hypothesis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klar, Amar J S</p> <p>2014-01-01</p> <p>The vertebrate body plan externally is largely symmetrical across the midline but internal organs develop asymmetrically. The biological basis of asymmetric organ development has been investigated extensively for years, although the proposed mechanisms remain controversial. By comparison, the biological origin of external organs symmetry has not been extensively investigated. Bimanual hand control is one such external organs symmetry allowing independent motor control movements of both hands to a person. This gap in our knowledge is illustrated by the recent reports of heterozygous rad51 mutations causing mysterious symptoms of congenital mirror hand movement disorder (MM) in humans with 50% penetrance by an unknown mechanism. The analysis of mutations that vary symmetry or asymmetry could be exploited to decipher the mechanisms of laterality development. Here I present a hypothesis for explaining 50% penetrance of the rad51 mutation. The MM's origin is explained with the Somatic Strand-specific Imprinting and selective sister <span class="hlt">chromatid</span> Segregation (SSIS) hypothesis proposed originally as the mechanism of asymmetric cell division to promote visceral organs body plan laterality development in vertebrates. By hypothesis, random sister <span class="hlt">chromatid</span> segregation in mitosis occurs for a specific chromosome due to rad51/RAD51 constitution causing MM disorder development in 50% of subjects. PMID:25210500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20090939','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20090939"><span id="translatedtitle">The MCM-binding protein ETG1 aids sister <span class="hlt">chromatid</span> cohesion required for postreplicative homologous recombination repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takahashi, Naoki; Quimbaya, Mauricio; Schubert, Veit; Lammens, Tim; Vandepoele, Klaas; Schubert, Ingo; Matsui, Minami; Inzé, Dirk; Berx, Geert; De Veylder, Lieven</p> <p>2010-01-01</p> <p>The DNA replication process represents a source of DNA stress that causes potentially spontaneous genome damage. This effect might be strengthened by mutations in crucial replication factors, requiring the activation of DNA damage checkpoints to enable DNA repair before anaphase onset. Here, we demonstrate that depletion of the evolutionarily conserved minichromosome maintenance helicase-binding protein ETG1 of Arabidopsis thaliana resulted in a stringent late G2 cell cycle arrest. This arrest correlated with a partial loss of sister <span class="hlt">chromatid</span> cohesion. The lack-of-cohesion phenotype was intensified in plants without functional CTF18, a replication fork factor needed for cohesion establishment. The synergistic effect of the etg1 and ctf18 mutants on sister <span class="hlt">chromatid</span> cohesion strengthened the impact on plant growth of the replication stress caused by ETG1 deficiency because of inefficient DNA repair. We conclude that the ETG1 replication factor is required for efficient cohesion and that cohesion establishment is essential for proper development of plants suffering from endogenous DNA stress. Cohesion defects observed upon knockdown of its human counterpart suggest an equally important developmental role for the orthologous mammalian ETG1 protein. PMID:20090939</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25081981','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25081981"><span id="translatedtitle">Regulation of centromere localization of the Drosophila Shugoshin MEI-S332 and sister-<span class="hlt">chromatid</span> cohesion in meiosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nogueira, Cristina; Kashevsky, Helena; Pinto, Belinda; Clarke, Astrid; Orr-Weaver, Terry L</p> <p>2014-07-31</p> <p>The Shugoshin (Sgo) protein family helps to ensure proper chromosome segregation by protecting cohesion at the centromere by preventing cleavage of the cohesin complex. Some Sgo proteins also influence other aspects of kinetochore-microtubule attachments. Although many Sgo members require Aurora B kinase to localize to the centromere, factors controlling delocalization are poorly understood and diverse. Moreover, it is not clear how Sgo function is inactivated and whether this is distinct from delocalization. We investigated these questions in Drosophila melanogaster, an organism with superb chromosome cytology to monitor Sgo localization and quantitative assays to test its function in sister-<span class="hlt">chromatid</span> segregation in meiosis. Previous research showed that in mitosis in cell culture, phosphorylation of the Drosophila Sgo, MEI-S332, by Aurora B promotes centromere localization, whereas Polo phosphorylation promotes delocalization. These studies also suggested that MEI-S332 can be inactivated independently of delocalization, a conclusion supported here by localization and function studies in meiosis. Phosphoresistant and phosphomimetic mutants for the Aurora B and Polo phosphorylation sites were examined for effects on MEI-S332 localization and chromosome segregation in meiosis. Strikingly, MEI-S332 with a phosphomimetic mutation in the Aurora B phosphorylation site prematurely dissociates from the centromeres in meiosis I. Despite the absence of MEI-S332 on meiosis II centromeres in male meiosis, sister <span class="hlt">chromatids</span> segregate normally, demonstrating that detectable levels of this Sgo are not essential for chromosome congression, kinetochore biorientation, or spindle assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12379012','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12379012"><span id="translatedtitle"><span class="hlt">Chromatid</span> gaps as a marker of mutagenic effect of environmental pollution in commensal and wild rodents of the Ural mountains.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gileva, E A</p> <p>2002-01-01</p> <p>It was supposed earlier that achromatic gaps could be used as markers of mutagenic effect of environmental pollution, especially under weaker clastogenic influences. The frequencies of true chromosome aberrations and those of <span class="hlt">chromatid</span> gaps were estimated in house mice and common voles from Uralian localities with various mutagenic potential of environment. Gaps and breaks were distinguished according to the CBIS system. In several localities, rodents displayed highly significant increase of the rates of cells with chromosome aberrations and with gaps as compared to the baseline values; only in the common vole, the P level for the gap increase was 0.056. The mean gap rate was correlated significantly with that of chromosome aberrations, not only with <span class="hlt">chromatid</span> breaks, but with the aberrations of other types, too. This parameter appears not to be more sensitive indicator of environmental mutagens than true chromosome mutations, when mutagenic impact is not very powerful, as it was in the localities investigated. The house mouse can be recommended as an effective test species for ecogenetic monitoring. PMID:12379012</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CoMP..164..341N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CoMP..164..341N"><span id="translatedtitle">Experimental Na/K <span class="hlt">exchange</span> between alkali feldspar and an NaCl-KCl salt melt: chemically <span class="hlt">induced</span> fracturing and element partitioning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neusser, G.; Abart, R.; Fischer, F. D.; Harlov, D.; Norberg, N.</p> <p>2012-08-01</p> <p>The <span class="hlt">exchange</span> of Na+ and K+ between alkali feldspar and a NaCl-KCl salt melt has been investigated experimentally. Run conditions were at ambient pressure and 850 °C as well as 1,000 °C. Cation <span class="hlt">exchange</span> occurred by interdiffusion of Na+ and K+ on the feldspar sub-lattice, while the Si-Al framework remained unaffected. Due to the compositional dependence of the lattice parameters compositional heterogeneities resulting from Na+/K+ interdiffusion <span class="hlt">induced</span> coherency stress and associated fracturing. Depending on the sense of chemical shift, different crack patterns developed. For the geometrically most regular case that developed when potassic alkali feldspar was shifted toward more sodium-rich compositions, a prominent set of cracks corresponding to tension cracks opened perpendicular to the direction of maximum tensile stress and did not follow any of the feldspar cleavage planes. The critical stress needed to initiate fracturing in a general direction of the feldspar lattice was estimated at ≤0.35 GPa. Fracturing provided fast pathways for penetration of salt melt or vapor into grain interiors enhancing overall cation <span class="hlt">exchange</span>. The Na/K partitioning between feldspar and the salt melt attained equilibrium values in the <span class="hlt">exchanged</span> portions of the grains allowing for extraction of the alkali feldspar mixing properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22416178','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22416178"><span id="translatedtitle">Collision-<span class="hlt">induced</span> absorption with <span class="hlt">exchange</span> effects and anisotropic interactions: Theory and application to H{sub 2} − H{sub 2}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karman, Tijs; Avoird, Ad van der; Groenenboom, Gerrit C.</p> <p>2015-02-28</p> <p>We discuss three quantum mechanical formalisms for calculating collision-<span class="hlt">induced</span> absorption spectra. First, we revisit the established theory of collision-<span class="hlt">induced</span> absorption, assuming distinguishable molecules which interact isotropically. Then, the theory is rederived incorporating <span class="hlt">exchange</span> effects between indistinguishable molecules. It is shown that the spectrum can no longer be written as an incoherent sum of the contributions of the different spherical components of the dipole moment. Finally, we derive an efficient method to include the effects of anisotropic interactions in the computation of the absorption spectrum. This method calculates the dipole coupling on-the-fly, which allows for the uncoupled treatment of the initial and final states without the explicit reconstruction of the many-component wave functions. The three formalisms are applied to the collision-<span class="hlt">induced</span> rotation-translation spectra of hydrogen molecules in the far-infrared. Good agreement with experimental data is obtained. Significant effects of anisotropic interactions are observed in the far wing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27160346','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27160346"><span id="translatedtitle">Flow-<span class="hlt">Induced</span> New Channels of Energy <span class="hlt">Exchange</span> in Multi-Scale Plasma Dynamics - Revisiting Perturbative Hybrid Kinetic-MHD Theory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shiraishi, Junya; Miyato, Naoaki; Matsunaga, Go</p> <p>2016-05-10</p> <p>It is found that new channels of energy <span class="hlt">exchange</span> between macro- and microscopic dynamics exist in plasmas. They are <span class="hlt">induced</span> by macroscopic plasma flow. This finding is based on the kinetic-magnetohydrodynamic (MHD) theory, which analyses interaction between macroscopic (MHD-scale) motion and microscopic (particle-scale) dynamics. The kinetic-MHD theory is extended to include effects of macroscopic plasma flow self-consistently. The extension is realised by generalising an energy <span class="hlt">exchange</span> term due to wave-particle resonance, denoted by δ WK. The first extension is generalisation of the particle's Lagrangian, and the second one stems from modification to the particle distribution function due to flow. These extensions lead to a generalised expression of δ WK, which affects the MHD stability of plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4861913','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4861913"><span id="translatedtitle">Flow-<span class="hlt">Induced</span> New Channels of Energy <span class="hlt">Exchange</span> in Multi-Scale Plasma Dynamics – Revisiting Perturbative Hybrid Kinetic-MHD Theory</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shiraishi, Junya; Miyato, Naoaki; Matsunaga, Go</p> <p>2016-01-01</p> <p>It is found that new channels of energy <span class="hlt">exchange</span> between macro- and microscopic dynamics exist in plasmas. They are <span class="hlt">induced</span> by macroscopic plasma flow. This finding is based on the kinetic-magnetohydrodynamic (MHD) theory, which analyses interaction between macroscopic (MHD-scale) motion and microscopic (particle-scale) dynamics. The kinetic-MHD theory is extended to include effects of macroscopic plasma flow self-consistently. The extension is realised by generalising an energy <span class="hlt">exchange</span> term due to wave-particle resonance, denoted by δ WK. The first extension is generalisation of the particle’s Lagrangian, and the second one stems from modification to the particle distribution function due to flow. These extensions lead to a generalised expression of δ WK, which affects the MHD stability of plasmas. PMID:27160346</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818255','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818255"><span id="translatedtitle">Peroxisome Proliferator–Activated Receptor α Protects Renal Tubular Cells from Gentamicin-<span class="hlt">Induced</span> Apoptosis via Upregulating Na+/H+ <span class="hlt">Exchanger</span> NHE1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Cheng-Hsien; Chen, Tso-Hsiao; Wu, Mei-Yi; Chen, Jia-Rung; Hong, Li-Yu; Zheng, Cai-Mei; Chiu, I-Jen; Lin, Yuh-Feng; Hsu, Yung-Ho</p> <p>2015-01-01</p> <p>Peroxisome proliferator–activated receptor (PPAR)-α is a transcription factor that has been reported to inhibit gentamicin-<span class="hlt">induced</span> apoptosis in renal tubular cells. However, the antiapoptotic mechanism of PPARα is still unknown. In this study, we found that PPARα overexpression <span class="hlt">induced</span> Na+/H+ <span class="hlt">exchanger</span>-1 (NHE1) expression in the rat renal tubular cells NRK-52E. Beraprost, a PPARα ligand, also increased NHE1 expression in the renal tubules in normal mice, but not in PPARα knockout mice. Chromatin immunoprecipitation assays revealed that two PPARα binding elements were located in the rat NHE1 promoter region. Na+/H+ <span class="hlt">exchanger</span> activity also increased in the PPARα-overexpressed cells. Flow cytometry showed that the PPARα-overexpressed cells were resistant to apoptosis-<span class="hlt">induced</span> shrinkage. Cariporide, a selective NHE1 inhibitor, inhibited the antiapoptotic effect of PPARα in the gentamicin-treated cells. The interaction between NHE1 and ezrin/radixin/moesin (ERM) and between ERM and phosphatidylinositol 4,5-bisphosphate in the PPARα-overexpressed cells was more than in the control cells. ERM short interfering RNA (siRNA) transfection inhibited the PPARα-<span class="hlt">induced</span> antiapoptotic effect. PPARα overexpression also increased the phosphoinositide 3-kinase (PI3K) expression, which is dependent on NHE1 activity. Increased PI3K further increased the phosphorylation of the prosurvival kinase Akt in the PPARα-overexpressed cells. Wortmannin, a PI3K inhibitor, inhibited PPARα-<span class="hlt">induced</span> Akt activity and the antiapoptotic effect. We conclude that PPARα <span class="hlt">induces</span> NHE1 expression and then recruits ERM to promote PI3K/Akt-mediated cell survival in renal tubular cells. The application of PPARα activation reduces the nephrotoxicity of gentamicin and may expand the clinical use of gentamicin. PMID:26623927</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1258605','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1258605"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; Liu, Ming</p> <p>2015-11-18</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shifted by up to |ΔH<sub>ex</sub>|/H<sub>ex</sub>=8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |ΔH<sub>ex</sub>|/H<sub>c</sub>=67.5~125% in NiFe/FeMn/glass/PZN-PT and 30~38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Lastly, electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8918903','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8918903"><span id="translatedtitle">The osmium tetroxide-p-phenylenediamine procedure reveals the <span class="hlt">chromatid</span> cores and kinetochores of meiotic chromosomes by light and electron microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Antonio, C; González-García, J M; Page, J; Suja, J A; Stockert, J C; Rufas, J S</p> <p>1996-11-01</p> <p>We analyzed first-metaphase meiotic chromosomes of the grasshopper Chorthippus jucundus by two different methods, i.e., a silver impregnation technique and the osmium tetroxide-p-phenylenediamine (Os-PPD) procedure. The former was applied on squashed testes previously fixed in ethanol-acetic acid, whereas for Os-PPD the material was not subjected to any previous extraction treatment but was fixed in OsO4, treated with PPD, and embedded in Epon 812. Both techniques revealed <span class="hlt">chromatid</span> cores and kinetochores regardless of the processing of the material (squashed or sectioned). Unstained Os-PPD sections were analyzed by light microscopy and transmission electron microscopy (TEM). The Os-PPD technique provided a high contrast of <span class="hlt">chromatid</span> cores and kinetochores in relation to the chromatin, which revealed a low electron density. To determine the Os-PPD reaction mechanism, the PAS procedure, as well as scanning electron microscopy (SEM) backscattering and SEM X-ray microanalysis, was performed on sections. By use of the Os-PPD-PAS procedure, glycol groups formed by oxidation of osmium bound to aromatic substrates were detected in <span class="hlt">chromatid</span> cores and kinetochores by brightfield and fluorescence microscopy. A high Z contrast was detected in these structures by backscattered electron imaging. SEM X-ray microanalysis showed osmium and phosphorus to be the main elements present on the <span class="hlt">chromatid</span> cores. Taking into account the known reactivity of OsO4 and the present results, the possible participation of nucleic acids as well as proteins in the Os-PPD reaction mechanism and in the composition of <span class="hlt">chromatid</span> cores and kinetochores is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=392011','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=392011"><span id="translatedtitle">Inhibition of epidermal growth factor-<span class="hlt">induced</span> mitogenesis by amiloride and an analog: evidence against a requirement for Na+/H+ <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Besterman, J M; Tyrey, S J; Cragoe, E J; Cuatrecasas, P</p> <p>1984-01-01</p> <p>We have tested the hypothesis that the rapid stimulation of Na+/H+ <span class="hlt">exchange</span> by epidermal growth factor (EGF) is a requirement for induction of mitogenesis. BALB/c 3T3 cells exposed for 4 hr at 37 degrees C to both EGF at 1 ng/ml and either 0.2-1 mM amiloride (an inhibitor of Na+/H+ <span class="hlt">exchange</span>) or 10 microM MK-685 (an amiloride analog and more potent inhibitor of Na+/H+ <span class="hlt">exchange</span>) incorporated no less [methyl-3H]thymidine during a 1-hr pulse 20 hr later than did cells exposed for 4 hr to EGF alone. Control experiments utilizing low external pH (to dissociate EGF from its receptor) and anti-EGF antibodies indicated that the failure of amiloride to inhibit mitogenesis when copresent with EGF during the first 4 hr was not due to incomplete removal of EGF and complete removal of amiloride at t4. Cells incubated with 200 microM amiloride for 24 hr showed nearly complete inhibition of stimulation by EGF. In comparison, cells incubated with 10 microM MK-685 for 24 hr showed only a slight inhibition of stimulation by EGF. Incubations with amiloride or MK-685 for shorter periods of time indicated that only amiloride inhibited mitogenesis and that this inhibition happened between 4 (t4) and 10(t10) hr after EGF addition, during which time increases in RNA and protein synthesis (required for mitogenesis) occurred. Amiloride inhibited both RNA and protein syntheses in intact cells during this prereplicative period, while MK-685 was without effect. We conclude that (i) inhibition of EGF-<span class="hlt">induced</span> mitogenesis by amiloride is due not to inhibition of EGF-stimulated Na+/H+ <span class="hlt">exchange</span> but rather to inhibition of necessary events occurring during the hours immediately prior to the onset of DNA synthesis, these events probably being RNA and protein synthesis and (ii) in cell culture medium buffered with CO2/HCO3-, complete inhibition of EGF-stimulated Na+/H+ <span class="hlt">exchange</span> does not inhibit EGF-<span class="hlt">induced</span> mitogenesis and, thus, stimulation of Na+/H+ <span class="hlt">exchange</span> is not necessary for induction of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3516844','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3516844"><span id="translatedtitle">Cdc42 and the Guanine Nucleotide <span class="hlt">Exchange</span> Factors Ect2 and Trio Mediate Fn14-<span class="hlt">Induced</span> Migration and Invasion of Glioblastoma Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fortin, Shannon P.; Ennis, Matthew J.; Schumacher, Cassie A.; Zylstra-Diegel, Cassandra R.; Williams, Bart O.; Ross, Julianna T.D.; Winkles, Jeffrey A.; Loftus, Joseph C.; Symons, Marc H.; Tran, Nhan L.</p> <p>2012-01-01</p> <p>Malignant glioblastomas are characterized by their ability to infiltrate into normal brain. We previously reported that binding of the multifunctional cytokine TNF-like weak <span class="hlt">inducer</span> of apoptosis (TWEAK) to its receptor fibroblast growth factor–<span class="hlt">inducible</span> 14 (Fn14) <span class="hlt">induces</span> glioblastoma cell invasion via Rac1 activation. Here, we show that Cdc42 plays an essential role in Fn14-mediated activation of Rac1. TWEAK-treated glioma cells display an increased activation of Cdc42, and depletion of Cdc42 using siRNA abolishes TWEAK-<span class="hlt">induced</span> Rac1 activation and abrogates glioma cell migration and invasion. In contrast, Rac1 depletion does not affect Cdc42 activation by Fn14, showing that Cdc42 mediates TWEAK-stimulated Rac1 activation. Furthermore, we identified two guanine nucleotide <span class="hlt">exchange</span> factors (GEF), Ect2 and Trio, involved in TWEAK-<span class="hlt">induced</span> activation of Cdc42 and Rac1, respectively. Depletion of Ect2 abrogates both TWEAK-<span class="hlt">induced</span> Cdc42 and Rac1 activation, as well as subsequent TWEAK-Fn14–directed glioma cell migration and invasion. In contrast, Trio depletion inhibits TWEAK-<span class="hlt">induced</span> Rac1 activation but not TWEAK-<span class="hlt">induced</span> Cdc42 activation. Finally, inappropriate expression of Fn14 or Ect2 in mouse astrocytes in vivo using an RCAS vector system for glial-specific gene transfer in G-tva transgenic mice <span class="hlt">induces</span> astrocyte migration within the brain, corroborating the in vitro importance of the TWEAK-Fn14 signaling cascade in glioblastoma invasion. Our results suggest that the TWEAK-Fn14 signaling axis stimulates glioma cell migration and invasion through two GEF-GTPase signaling units, Ect2-Cdc42 and Trio-Rac1. Components of the Fn14-Rho GEF-Rho GTPase signaling pathway present innovative drug targets for glioma therapy. PMID:22571869</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3161789','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3161789"><span id="translatedtitle">The Na+/H+ <span class="hlt">Exchanger</span> Controls Deoxycholic Acid-<span class="hlt">Induced</span> Apoptosis by a H+-Activated, Na+-Dependent Ionic Shift in Esophageal Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Goldman, Aaron; Chen, HwuDauRw; Khan, Mohammad R.; Roesly, Heather; Hill, Kimberly A.; Shahidullah, Mohammad; Mandal, Amritlal; Delamere, Nicholas A.; Dvorak, Katerina</p> <p>2011-01-01</p> <p>Apoptosis resistance is a hallmark of cancer cells. Typically, bile acids <span class="hlt">induce</span> apoptosis. However during gastrointestinal (GI) tumorigenesis the cancer cells develop resistance to bile acid-<span class="hlt">induced</span> cell death. To understand how bile acids <span class="hlt">induce</span> apoptosis resistance we first need to identify the molecular pathways that initiate apoptosis in response to bile acid exposure. In this study we examined the mechanism of deoxycholic acid (DCA)-<span class="hlt">induced</span> apoptosis, specifically the role of Na+/H+ <span class="hlt">exchanger</span> (NHE) and Na+ influx in esophageal cells. In vitro studies revealed that the exposure of esophageal cells (JH-EsoAd1, CP-A) to DCA (0.2 mM -0.5 mM) caused lysosomal membrane perturbation and transient cytoplasmic acidification. Fluorescence microscopy in conjunction with atomic absorption spectrophotometry demonstrated that this effect on lysosomes correlated with influx of Na+, subsequent loss of intracellular K+, an increase of Ca2+ and apoptosis. However, ethylisopropyl-amiloride (EIPA), a selective inhibitor of NHE, prevented Na+, K+ and Ca2+ changes and caspase 3/7 activation <span class="hlt">induced</span> by DCA. Ouabain and amphotericin B, two drugs that increase intracellular Na+ levels, <span class="hlt">induced</span> similar changes as DCA (ion imbalance, caspase3/7 activation). On the contrary, DCA-<span class="hlt">induced</span> cell death was inhibited by medium with low a Na+ concentrations. In the same experiments, we exposed rat ileum ex-vivo to DCA with or without EIPA. Severe tissue damage and caspase-3 activation was observed after DCA treatment, but EIPA almost fully prevented this response. In summary, NHE-mediated Na+ influx is a critical step leading to DCA-<span class="hlt">induced</span> apoptosis. Cells tolerate acidification but evade DCA-<span class="hlt">induced</span> apoptosis if NHE is inhibited. Our data suggests that suppression of NHE by endogenous or exogenous inhibitors may lead to apoptosis resistance during GI tumorigenesis. PMID:21887327</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9485541','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9485541"><span id="translatedtitle">Inhibition of sulfotransferase affecting in vivo genotoxicity and DNA adducts <span class="hlt">induced</span> by safrole in rat liver.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daimon, H; Sawada, S; Asakura, S; Sagami, F</p> <p></p> <p>The effect of pretreatment with pentachlorophenol (PCP), a known inhibitor of sulfotransferases, on the induction of chromosomal aberrations, sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs), replicative DNA synthesis (RDS), and the formation of DNA adducts was studied in the liver of rats treated with safrole (1-allyl-3,4-methylenedioxy-benzene). Rats were given a single oral dose (1,000 mg/kg body weight) or 5 repeated doses (500 mg/kg body weight) of safrole, with or without intraperitoneal pretreatment with PCP (10 mg/kg body weight). Hepatocytes were isolated 24 hr after administration of safrole and allowed to proliferate in Williams' medium E supplemented with epidermal growth factor to test for chromosomal aberrations and SCEs. For examination of RDS, hepatocytes were incubated in Williams' medium E containing 5-bromo-2'-deoxyuridine. Safrole-DNA adducts were detected by a nuclease P1-enhanced 32P-postlabeling assay. A single dose of safrole <span class="hlt">induced</span> significant SCEs and RDS, while chromosomal aberrations were <span class="hlt">induced</span> by 5 repeated doses. Two major and 2 minor DNA adducts were detected by both a single dose and 5 repeated doses. PCP significantly decreased safrole-<span class="hlt">induced</span> cytogenetic effects and RDS, and caused a decrease in DNA adducts formed by safrole. These results suggest that safrole is capable of <span class="hlt">inducing</span> SCEs, chromosomal aberrations, and RDS in the rat liver in vivo and that these effects may be <span class="hlt">induced</span> by the sulfuric acid ester metabolite that can bind DNA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1210146-exchange-bias-effect-au-fe3o4-dumbbell-nanoparticles-induced-charge-transfer-from-gold','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1210146-exchange-bias-effect-au-fe3o4-dumbbell-nanoparticles-induced-charge-transfer-from-gold"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe3O4 dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; et al</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatchmore » between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1240279','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1240279"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe3O4 dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Feygenson, Mikhail; Bauer, John C.; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S.; Beyer, Kevin A.; Dai, Sheng</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron-scattering, synchrotron x-ray diffraction, and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into the FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed, presumably across the interface to accommodate an excess of oxygen released during the reduction of magnetite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1172322','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1172322"><span id="translatedtitle">The investigation of substrate-<span class="hlt">induced</span> changes in subunit interactions in glyceraldehyde 3-phosphate dehydrogenases by measurement of the kinetics and thermodynamics of subunit <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Osborne, H H; Hollaway, M R</p> <p>1975-01-01</p> <p>An investigation was made of changes in subunit interactions in glyceraldehyde 3-phosphate dehydrogenase on binding NAD+, NADH and other substrates by using the previously developed method of measurement of rates and extent of subunit <span class="hlt">exchange</span> between the rabbit enzyme (R4), yeast enzyme (Y4) and rabbit-yeast hybrid (R2Y2) [Osborne & Hollaway (1974) Biochem. J. 143, 651-662]. The free energy of activation for the conversion of tetramer into dimer for the rabbit enzyme (R4 leads to 2R2) is increased by at least 12kJ/mol in the presence of NAD+. This increase is interpreted in terms of an NAD+-<span class="hlt">induced</span> 'tightening' of the tetrameric structure probably involving increased interaction at the subunit interfaces across the QR plane of the molecule [see Buehner et al. (1974) J. Mol. Biol. 82, 563-585]. This tightening of the structure only occurs on binding the third NAD+ molecule to a given enzyme molecule. Conversely, binding of NADH causes a decrease in the free energy of activation for the R4 leads to 2R2 and Y4 leads to 2Y2 conversions by at least 10kJ/mol. This is interpreted as a NADH-<span class="hlt">induced</span> 'loosening' of the structures arising from decreased interactions across the subunit interfaces involving the QR dissociation plane. In the presence of NADH the increase in the rate of subunit <span class="hlt">exchange</span> is such that it is not possible to separate the hybrid from the other species if electrophoresis is carried out with NADH in the separation media. In the presence of a mixture of NADH and NAD+ the effect of NAD+ on subunit <span class="hlt">exchange</span> is dominant. The results are discussed in terms of the known co-operativty between binding sites in glyceraldehyde 3-phosphate dehydrogenases. Images PLATE 1(a) PLATE 1(b) PLATE 2(a) PLATE 2(b) PLATE 2(c) PMID:174555</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17121119','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17121119"><span id="translatedtitle">Evaluating effects of wind-<span class="hlt">induced</span> pressure fluctuations on soil-atmosphere gas <span class="hlt">exchange</span> at a landfill using stochastic modelling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poulsen, Tjalfe G; Møldrup, Per</p> <p>2006-10-01</p> <p>The impact of wind turbulence-<span class="hlt">induced</span> pressure fluctuations at the soil surface on landfill gas transport and emissions to the atmosphere at an old Danish landfill site was investigated using stochastic modelling combined with soil property and gas transport data measured at the site. The impacts of soil physical properties (including air permeability and volumetric water content) and wind-<span class="hlt">induced</span> pressure fluctuation properties (amplitude and temporal correlation) on landfill gas emissions to the atmosphere were evaluated. Soil-air permeability and pressure fluctuation amplitude were found to be the most important parameters. Wind-<span class="hlt">induced</span> gas emissions were further compared with gas emissions caused by diffusion and by long-term pressure variations (due to passing weather systems). Here diffusion and wind-<span class="hlt">induced</span> gas transport were found to be equally important with wind-<span class="hlt">induced</span> gas transport becoming the most important at lower soil-air contents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CSR....92...44L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CSR....92...44L"><span id="translatedtitle">Sediment-water <span class="hlt">exchange</span> of nutrients in the Marsdiep basin, western Wadden Sea: Phosphorus limitation <span class="hlt">induced</span> by a controlled release?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leote, Catarina; Epping, Eric H. G.</p> <p>2015-01-01</p> <p>To quantify the release of inorganic phosphorus from the sediments and assess its contribution to present primary production, a basin-wide study of the Marsdiep (western Wadden Sea, The Netherlands) was performed. Two distinct sedimentary zones were identified: a depositional area characterized by a high content of silt and organic carbon and a small grain size and the majority of the area, composed of fine/medium sand and a low organic carbon content. The sediment-water <span class="hlt">exchange</span> was higher in the fine grained depositional area and based on a relationship found between the release of inorganic phosphorus and the silt content, a total annual release of 1.0×107 mol P was estimated for the whole Marsdiep basin. A spatial variability in the processes controlling the nutrient release was found. The <span class="hlt">exchange</span> in the depositional area resulted mainly from molecular diffusive transport, with mineralization and sorption determining the concentration of inorganic phosphorus in the porewater. For the coarser sediment stations the activity of macrofauna clearly enhanced the fluxes. Given the relative demand of nutrients (N:P:Si) for phytoplankton growth, the release was phosphorus deficient during most of the year. Nevertheless, it increased from February until September, in parallel with the increase in temperature and light, thus having the potential to fuel primary production during their seasonal growth period. In terms of absolute values, our results show that the present <span class="hlt">exchange</span>, enhanced by the activity of macrofauna has the potential to fuel a significant fraction of the recent levels of primary productivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18589618','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18589618"><span id="translatedtitle">[An overview on biomarkers of arsenic-<span class="hlt">induced</span> health hazardsan].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>An, Yan; Yin, Lijuan; Wang, Sanxiang; Wang, Zhenghui; et al</p> <p>2008-03-01</p> <p>A series of molecular environmental epidemiological studies have been carried out to elucidate biomarkers of exposure, effect, and susceptibility for arsenic-related health hazards in Taiwan area in China. Arsenic levels in urine, hair, and nail could be biomarkers for short-term internal dose, skin hyperpigmentation and palmoplantar hyperkeratosis could be biomarkers for long-term (many years) internal dose, and percentage of monomethylarsonic acid in total metabolites of inorganic arsenic in urine could be considered as an exposure marker for biologically effective dose. The biomarkers of early biological effects of ingested inorganic arsenic could include blood levels of reactive oxidants and antioxidant capacity, genetic expression of inflammatory molecules, as well as cytogenetic changes including sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span>, micronuclei, and chromosome aberrations of peripheral lymphocytes. Biomarkers of susceptibility to arsenic-<span class="hlt">induced</span> health hazards could include genetic polymorphisms of enzymes involved in xenobiotic metabolism, DNA repair, and oxidative stress, as well as serum level of carotenoids. Gene-gene and gene-environment interactions could be involved in arsenic-<span class="hlt">induced</span> health hazards through toxicological mechanisms including genomic instability and oxidative stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21143909','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21143909"><span id="translatedtitle">Involvement of Na{sup +}/H{sup +} <span class="hlt">exchanger</span> 1 in advanced glycation end products-<span class="hlt">induced</span> proliferation of vascular smooth muscle cell</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu Shujin; Song Tao; Zhou Shouhong; Liu Yuhui; Chen Gengrong; Huang Ningjiang; Liu Liying</p> <p>2008-10-24</p> <p>In this present study, we examined the role of Na{sup +}/H{sup +} <span class="hlt">exchanger</span> 1 (NHE1) in the cultured rat vascular smooth muscle cell (VSMC) proliferation <span class="hlt">induced</span> by advanced glycation end products (AGEs). AGEs significantly increased the [{sup 3}H] thymidine incorporation of VSMC. Cariporide, an NHE1 inhibitor, dose-dependently attenuated the AGEs-<span class="hlt">induced</span> increase in cell DNA synthesis. Thus the effect of AGEs on NHE1 activity was next examined. The cariporide-dependent intracellular pH (pH{sub i}) was significantly increased after 24 h exposure to AGEs (10 {mu}g/ml). The direct AGEs-<span class="hlt">induced</span> NHE1 activation was measured by the Na{sup +}-dependent intracellular pH recovery from intracellular acidosis. AGEs can increase the NHE1 activity in a time- and concentration-dependent manner. Inhibition of either the receptor for AGEs (RAGE) by anti-RAGE or mitogen-activated protein kinases (MAPK) by PD98059 reversed the effect of AGEs on NHE1 activity. Reverse transcription (RT)-PCR analysis revealed that AGEs dose-dependently increased NHE1 mRNA at 24 h. These findings demonstrate NHE1 is required for in AGEs-<span class="hlt">induced</span> proliferation of VSMC, and AGEs increase NHE1 activity via the MAPK pathway.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3387235','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3387235"><span id="translatedtitle">Absence of Ca2+-<span class="hlt">Induced</span> Mitochondrial Permeability Transition but Presence of Bongkrekate-Sensitive Nucleotide <span class="hlt">Exchange</span> in C. crangon and P. serratus</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Konrad, Csaba; Kiss, Gergely; Torocsik, Beata; Adam-Vizi, Vera; Chinopoulos, Christos</p> <p>2012-01-01</p> <p>Mitochondria from the embryos of brine shrimp (Artemia franciscana) do not undergo Ca2+-<span class="hlt">induced</span> permeability transition in the presence of a profound Ca2+ uptake capacity. Furthermore, this crustacean is the only organism known to exhibit bongkrekate-insensitive mitochondrial adenine nucleotide <span class="hlt">exchange</span>, prompting the conjecture that refractoriness to bongkrekate and absence of Ca2+-<span class="hlt">induced</span> permeability transition are somehow related phenomena. Here we report that mitochondria isolated from two other crustaceans, brown shrimp (Crangon crangon) and common prawn (Palaemon serratus) exhibited bongkrekate-sensitive mitochondrial adenine nucleotide transport, but lacked a Ca2+-<span class="hlt">induced</span> permeability transition. Ca2+ uptake capacity was robust in the absence of adenine nucleotides in both crustaceans, unaffected by either bongkrekate or cyclosporin A. Transmission electron microscopy images of Ca2+-loaded mitochondria showed needle-like formations of electron-dense material strikingly similar to those observed in mitochondria from the hepatopancreas of blue crab (Callinectes sapidus) and the embryos of Artemia franciscana. Alignment analysis of the partial coding sequences of the adenine nucleotide translocase (ANT) expressed in Crangon crangon and Palaemon serratus versus the complete sequence expressed in Artemia franciscana reappraised the possibility of the 208-214 amino acid region for conferring sensitivity to bongkrekate. However, our findings suggest that the ability to undergo Ca2+-<span class="hlt">induced</span> mitochondrial permeability transition and the sensitivity of adenine nucleotide translocase to bongkrekate are not necessarily related phenomena. PMID:22768139</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1360302','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1360302"><span id="translatedtitle"><span class="hlt">Exchange</span> of Lipooligosaccharide Synthesis Genes Creates Potential Guillain-Barré Syndrome-<span class="hlt">Inducible</span> Strains of Campylobacter jejuni</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Phongsisay, Vongsavanh; Perera, Viraj N.; Fry, Benjamin N.</p> <p>2006-01-01</p> <p>Human ganglioside-like structures, such as GM1, found on some Campylobacter jejuni strains have been linked to <span class="hlt">inducing</span> the Guillain-Barré Syndrome (GBS). This study shows that a C. jejuni strain without GM1-like molecules acquired large DNA fragments, including lipooligosaccharide synthesis genes, from a strain expressing GM1-like molecules and consequently transformed into a number of potential GBS-<span class="hlt">inducible</span> transformants, which exhibited a high degree of genetic and phenotypic diversity. PMID:16428786</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1213073R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1213073R"><span id="translatedtitle">Spatio-temporal variations of plant mediated <span class="hlt">exchange</span> - diurnal and seasonal changes of the function status of plant canopies measured by sun-<span class="hlt">induced</span> fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rascher, Uwe; Schickling, Anke; Crewell, Susanne; Schween, Jan; Geiß, Heiner</p> <p>2010-05-01</p> <p>Fluxes of plant mediated <span class="hlt">exchange</span> processes are large and substantially influence patterns in atmospheric CO2 concentrations and water vapor. Plant canopies are not constant, but continuously adapt their physiology to the ever changing environmental conditions. Structural changes of plant canopies mainly occur on the time scale of weeks and seasons and are generally parametrized in regional and global carbon and water models. Changes of the physiological status of plant ecosystems, however, may occur within hours or a few days and are often not accounted for in models. Nevertheless, a reduction of photosynthesis because of e.g. stress may greatly reduce carbon and water <span class="hlt">exchange</span> below the theoretical optimum. Such physiological changes are often are not correctly parametrized in spatially explicit and high resolution carbon and water models. For a better understanding of the diurnal and seasonal variations of soil-vegetation-atmosphere <span class="hlt">exchange</span> processes, the structure and function of two main agricultural crops were monitored over two years in the frame of the collaborative research consortium Transregio TR32. Seasonal development of the two main crops of the region, winter wheat and sugar beet, has been characterized during diurnal courses using non invasive methods ranging from leaf to canopy level including gas <span class="hlt">exchange</span>, PAM fluorometry and eddy correlation measurements. The day course of photosynthetic capacity varied between the two species by being constant during the day for winter wheat whereas sugar beet showed a constant decrease over the day. The highest photosynthetic electron transport rates appeared before solar noon. Additionally the region was scanned by an airborne high-resolution spectrometer that allowed the extraction of sun-<span class="hlt">induced</span> fluorescence. Sun-<span class="hlt">induced</span> fluorescence is currently evaluated to serve as a direct measure of photosynthetic efficiency from air- and spaceborne platforms. In this presentation we present the first conceptual view</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6801231','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6801231"><span id="translatedtitle">mRNA-<span class="hlt">induced</span> expression of the cardiac Na/sup +/-Ca/sup 2 +/ <span class="hlt">exchanger</span> in Xenopus oocytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sigel, E.; Baur, R.; Porzig, H.; Reuter, H.</p> <p>1988-10-15</p> <p>Xenopus oocytes were injected with total mRNA isolated from hearts of 1-day-old chicks. After 5 days of incubation the follicular cell layers were removed and the oocytes were loaded with Na+ by incubation in hypertonic EGTA solution at 37/sup 0/C. The Na+-loaded oocytes accumulated /sup 45/Ca/sup 2 +/ from a Na+-free medium at a 3-18-fold higher rate than noninjected oocytes or oocytes injected with control solution containing no mRNA. Oocytes not subjected to the Na+-loading procedure showed no mRNA-dependent /sup 45/Ca/sup 2 +/ uptake. Size fractionation of the mRNA using sucrose density gradient centrifugation under denaturing conditions led to the identification of a 25 S fraction competent for induction of the Na/sup +/-Ca/sup 2 +/ <span class="hlt">exchange</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..91v0407S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..91v0407S"><span id="translatedtitle"><span class="hlt">Exchange</span>-striction <span class="hlt">induced</span> giant ferroelectric polarization in copper-based multiferroic material α -Cu2V2O7</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sannigrahi, J.; Bhowal, S.; Giri, S.; Majumdar, S.; Dasgupta, I.</p> <p>2015-06-01</p> <p>We report α -Cu2V2O7 to be an improper multiferroic with the simultaneous development of electric polarization and magnetization below TC=35 K . The observed spontaneous polarization of 0.55 μ C cm-2 magnitude is highest among copper-based improper multiferroic materials. Our study demonstrates a sizable amount of magnetoelectric coupling below TC, even with a low magnetic field. The theoretical calculations based on density functional theory indicate magnetism in α -Cu2V2O7 is a consequence of ferro-orbital ordering driven by a polar lattice distortion due to the unique pyramidal (CuO5) environment of Cu. Spin-orbit coupling further stabilizes orbital ordering and is crucial for magnetism. The calculations indicate that the origin of the giant ferroelectric polarization is primarily due to the symmetric <span class="hlt">exchange</span>-striction mechanism and is corroborated by temperature-dependent x-ray studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3376262','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3376262"><span id="translatedtitle">Multiple meiotic errors caused by predivision of <span class="hlt">chromatids</span> in women of advanced maternal age undergoing in vitro fertilisation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Handyside, Alan H; Montag, Markus; Magli, M Cristina; Repping, Sjoerd; Harper, Joyce; Schmutzler, Andreas; Vesela, Katerina; Gianaroli, Luca; Geraedts, Joep</p> <p>2012-01-01</p> <p>Chromosome aneuploidy is a major cause of pregnancy loss, abnormal pregnancy and live births following both natural conception and in vitro fertilisation (IVF) and increases exponentially with maternal age in the decade preceding the menopause. Molecular genetic analysis following natural conception and spontaneous miscarriage demonstrates that trisomies arise mainly in female meiosis and particularly in the first meiotic division. Here, we studied copy number gains and losses for all chromosomes in the two by-products of female meiosis, the first and second polar bodies, and the corresponding zygotes in women of advanced maternal age undergoing IVF, using microarray comparative genomic hybridisation (array CGH). Analysis of the segregation patterns underlying the copy number changes reveals that premature predivision of <span class="hlt">chromatids</span> rather than non-disjunction of whole chromosomes causes almost all errors in the first meiotic division and unlike natural conception, over half of aneuploidies result from errors in the second meiotic division. Furthermore, most abnormal zygotes had multiple aneuploidies. These differences in the aetiology of aneuploidy in IVF compared with natural conception may indicate a role for ovarian stimulation in perturbing meiosis in ageing oocytes. PMID:22317970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4282573','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4282573"><span id="translatedtitle">SNW1 enables sister <span class="hlt">chromatid</span> cohesion by mediating the splicing of sororin and APC2 pre-mRNAs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van der Lelij, Petra; Stocsits, Roman R; Ladurner, Rene; Petzold, Georg; Kreidl, Emanuel; Koch, Birgit; Schmitz, Julia; Neumann, Beate; Ellenberg, Jan; Peters, Jan-Michael</p> <p>2014-01-01</p> <p>Although splicing is essential for the expression of most eukaryotic genes, inactivation of splicing factors causes specific defects in mitosis. The molecular cause of this defect is unknown. Here, we show that the spliceosome subunits SNW1 and PRPF8 are essential for sister <span class="hlt">chromatid</span> cohesion in human cells. A transcriptome-wide analysis revealed that SNW1 or PRPF8 depletion affects the splicing of specific introns in a subset of pre-mRNAs, including pre-mRNAs encoding the cohesion protein sororin and the APC/C subunit APC2. SNW1 depletion causes cohesion defects predominantly by reducing sororin levels, which causes destabilisation of cohesin on DNA. SNW1 depletion also reduces APC/C activity and contributes to cohesion defects indirectly by delaying mitosis and causing “cohesion fatigue”. Simultaneous expression of sororin and APC2 from intron-less cDNAs restores cohesion in SNW1-depleted cells. These results indicate that the spliceosome is required for mitosis because it enables expression of genes essential for cohesion. Our transcriptome-wide identification of retained introns in SNW1- and PRPF8-depleted cells may help to understand the aetiology of diseases associated with splicing defects, such as retinosa pigmentosum and cancer. PMID:25257309</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26350456','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26350456"><span id="translatedtitle">Na-H <span class="hlt">Exchanger</span> Isoform-2 (NHE2) Mediates Butyrate-dependent Na+ Absorption in Dextran Sulfate Sodium (DSS)-<span class="hlt">induced</span> Colitis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rajendran, Vazhaikkurichi M; Nanda Kumar, Navalpur S; Tse, Chung M; Binder, Henry J</p> <p>2015-10-16</p> <p>Diarrhea associated with ulcerative colitis (UC) occurs primarily as a result of reduced Na(+) absorption. Although colonic Na(+) absorption is mediated by both epithelial Na(+) channels (ENaC) and Na-H <span class="hlt">exchangers</span> (NHE), inhibition of NHE-mediated Na(+) absorption is the primary cause of diarrhea in UC. As there are conflicting observations reported on NHE expression in human UC, the present study was initiated to identify whether NHE isoforms (NHE2 and NHE3) expression is altered and how Na(+) absorption is regulated in DSS-<span class="hlt">induced</span> inflammation in rat colon, a model that has been used to study UC. Western blot analyses indicate that neither NHE2 nor NHE3 expression is altered in apical membranes of inflamed colon. Na(+) fluxes measured in vitro under voltage clamp conditions in controls demonstrate that both HCO3 (-)-dependent and butyrate-dependent Na(+) absorption are inhibited by S3226 (NHE3-inhibitor), but not by HOE694 (NHE2-inhibitor) in normal animals. In contrast, in DSS-<span class="hlt">induced</span> inflammation, butyrate-, but not HCO3 (-)-dependent Na(+) absorption is present and is inhibited by HOE694, but not by S3226. These observations indicate that in normal colon NHE3 mediates both HCO3 (-)-dependent and butyrate-dependent Na(+) absorption, whereas DSS-<span class="hlt">induced</span> inflammation activates NHE2, which mediates butyrate-dependent (but not HCO3 (-)-dependent) Na(+) absorption. In in vivo loop studies HCO3 (-)-Ringer and butyrate-Ringer exhibit similar rates of water absorption in normal rats, whereas in DSS-<span class="hlt">induced</span> inflammation luminal butyrate-Ringer reversed water secretion observed with HCO3 (-)-Ringer to fluid absorption. Lumen butyrate-Ringer incubation activated NHE3-mediated Na(+) absorption in DSS-<span class="hlt">induced</span> colitis. These observations suggest that the butyrate activation of NHE2 would be a potential target to control UC-associated diarrhea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22268690','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22268690"><span id="translatedtitle">Sorption-<span class="hlt">induced</span> effects of humic substances on mass transfer of organic pollutants through aqueous diffusion boundary layers: the example of water/air <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramus, Ksenia; Kopinke, Frank-Dieter; Georgi, Anett</p> <p>2012-02-21</p> <p>This study examines the effect of dissolved humic substances (DHS) on the rate of water-gas <span class="hlt">exchange</span> of organic compounds under conditions where diffusion through the aqueous boundary layer is rate-determining. A synthetic surfactant was applied for comparison. Mass-transfer coefficients were determined from the rate of depletion of the model compounds by means of an apparatus containing a stirred aqueous solution with continuous purging of the headspace above the solution. In addition, experiments with continuous passive dosing of analytes into the water phase were conducted to simulate a system where thermodynamic activity of the chemical in the aqueous phase is identical in the presence and absence of DHS. The experimental results show that DHS and surfactants can affect water-gas <span class="hlt">exchange</span> rates by the superposition of two mechanisms: (1) hydrodynamic effects due to surface film formation ("surface smoothing"), and (2) sorption-<span class="hlt">induced</span> effects. Whether sorption accelerates or retards mass transfer depends on its effect on the thermodynamic activity of the pollutant in the aqueous phase. Mass transfer will be retarded if the activity (or freely dissolved concentration) of the pollutant is decreased due to sorption. If it remains unchanged (e.g., due to fast equilibration with a sediment acting as a large source phase), then DHS and surfactant micelles can act as an additional shuttle for the pollutants, enhancing the flux through the boundary layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6654578','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6654578"><span id="translatedtitle">Repair of chromosome damage <span class="hlt">induced</span> by X-irradiation during G2 phase in a line of normal human fibroblasts and its malignant derivative</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parshad, R.; Gantt, R.; Sanford, K.K.; Jones, G.M.; Tarone, R.E.</p> <p>1982-08-01</p> <p>A line of normal human skin fibroblasts (KD) differed from its malignant derivative (HUT-14) in the extent of cytogenetic damage <span class="hlt">induced</span> by X-irradiation during G2 phase. Malignant cells had significantly more <span class="hlt">chromatid</span> breaks and gaps after exposure to 25, 50, or 100 rad. The gaps may represent single-strand breaks. Results from alkaline elution of cellular DNA immediately after irradiation showed that the normal and malignant cells in asynchronous population were equally sensitive to DNA single-strand breakage by X-irradiation. Caffeine or beta-cytosine arabinoside (ara-C), inhibitors of DNA repair, when added directly following G2 phase exposure, significantly increased the incidence of radiation-<span class="hlt">induced</span> <span class="hlt">chromatid</span> damage in the normal cells. In contrast, similar treatment of the malignant cells had little influence. Ara-C differed from caffeine in its effects; whereas both agents increased the frequency of <span class="hlt">chromatid</span> breaks and gaps, only ara-C increased the frequency of gaps to the level observed in the irradiated malignant cells. Addition of catalase, a scavenger of the derivative free hydroxyl radical (.OH), to the cultures of malignant cells before, during, and following irradiation significantly reduced the <span class="hlt">chromatid</span> damage; and catalase prevented formation of <span class="hlt">chromatid</span> gaps. The DNA damage <span class="hlt">induced</span> by X-ray during G2 phase in the normal KD cells was apparently repaired by a caffeine- and ara-C-sensitive mechanism(s) that was deficient or absent in their malignant derivatives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12787576','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12787576"><span id="translatedtitle">The role of the <span class="hlt">exchanges</span> through the Strait of Gibraltar on the budget of elements in the Western Mediterranean Sea: consequences of human-<span class="hlt">induced</span> modifications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gómez, Fernando</p> <p>2003-06-01</p> <p>The role of the Strait of Gibraltar on the <span class="hlt">exchanges</span> of substances between Mediterranean Sea and the Atlantic Ocean is reviewed. The previous estimations have been recalculated by using a similar water flux and compared with the river and atmospheric inputs to the Western Mediterranean Sea. The man-<span class="hlt">induced</span> changes in the dimensions of the Strait of Gibraltar increasing (planning the sill) or reducing of the cross-section by a total or partial dam are discussed. A total dam will control the sea-level rise in the Mediterranean Sea, but an annual increase of major nutrient concentrations of 1-2% could be expected, lower than the rate of increase of the river and atmospheric inputs in the Western Mediterranean Sea. The increase of the cross-section of the Strait by increasing the depth (planning) at the sill could compensate the increase of the external nutrient inputs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22275803','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22275803"><span id="translatedtitle"><span class="hlt">Exchange</span> bias and magnetic properties <span class="hlt">induced</span> by intrinsic structural distortion in CaMn{sub 3}O{sub 6} nanoribbons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yu, J. Y. Huang, K.; Wu, H. Y.; Feng, Y.; Tang, Z.; Zhang, L.; Wang, L.</p> <p>2014-01-13</p> <p>Single-crystalline CaMn{sub 3}O{sub 6} nanoribbons have been synthesized by a molten-salt method. To explore the origin of the magnetism of nanosized antiferromagnetic (AFM) manganites, a comparative study has been conducted for CaMn{sub 3}O{sub 6} (CMO-1) and post-growth vacuum annealed (CMO-2) nanoribbons. A lattice expansion resulting from oxygen release during vacuum annealing is observed. Correspondingly, AFM ordering in CMO-2 is further suppressed, and ferromagnetism and spin-glass (SG)-like behavior are significantly enhanced, which are presumed attributable to the intrinsic structural distortions <span class="hlt">induced</span> by oxygen vacancies. In this case, side and surface effects are not decisive factors. In addition, this study provided observations of the <span class="hlt">exchange</span> bias effect in manganite nanoribbons with an AFM-SG-like-ferromagnetic (FM) structure, as compared with the typical AFM-core-FM-shell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25549454','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25549454"><span id="translatedtitle">[Evaluation of <span class="hlt">induced</span> mutagenesis in workers engaged into chrysotile asbestos production].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhumabekova, G S; Amanbekova, A U; Ibraeva, L K; Azhimetova, G N</p> <p>2014-01-01</p> <p>The authors present data of cytogenetic study of workers engaged into chrysotile asbestos industry. Evaluation of chromosomal aberrations in peripheral lymphocytes of workers in main workshops of "Kustanaiskie mineral" JSC revealed reliable increase in chromosomal aberrations level. Structural chromosomal abnormalities in main groups were presented by chromosome and <span class="hlt">chromatide</span> type aberrations with latter prevelent--that can prove chemical mutagenesis. Chromosome type aberrations were presented by paired fragments and centromere rupture, those of <span class="hlt">chromatide</span> type--by deletions, single fragments and <span class="hlt">chromatide</span> ruptures. Higher values of <span class="hlt">induced</span> mutagenesis were revealed in workers of chrysotile asbestos ore concentration workshop, in workers of ore-preparation workshop, and in individuals with over 25 years of work at chrysotile asbestos production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16226744','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16226744"><span id="translatedtitle">Effects of KR-32570, a new sodium hydrogen <span class="hlt">exchanger</span> inhibitor, on myocardial infarction and arrhythmias <span class="hlt">induced</span> by ischemia and reperfusion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Byung Ho; Yi, Kyu Yang; Lee, Sunkyung; Lee, Sunghou; Yoo, Sung-eun</p> <p>2005-10-31</p> <p>The present study was performed to evaluate the cardioprotective effects of [5-(2-methoxy-5-chloro-5-phenyl)furan-2-ylcarbonyl]guanidine (KR-32570) in rat and dog models of coronary artery occlusion and reperfusion. In addition, we sought to clarify the efficacy of KR-32570 on reperfusion-<span class="hlt">induced</span> fatal ventricular arrhythmia. In anesthetized rats subjected to 45-min coronary occlusion and 90-min reperfusion, KR-32570 (i.v. bolus) dose-dependently reduced myocardial infarct size from 58.0% to 50.7%, 35.3%, 33.5% and 27.0% for 0.03, 0.1, 0.3 and 1.0 mg/kg, respectively (P<0.05). In anesthetized beagle dogs that underwent 1.2-h occlusion followed by 3.0-h reperfusion, KR-32570 (3 mg/kg, i.v. bolus) markedly decreased infarct size from 28.9% in vehicle-treated group to 8.0% (P<0.05), and reduced the reperfusion-<span class="hlt">induced</span> release in creatine kinase isoenzyme MB, lactate dehydrogenase, Troponin-I and glutamic-oxaloacetic transaminase. KR-32570 dose-dependently decreased the incidence of premature ventricular contraction, ventricular tachycardia or ventricular fibrillation <span class="hlt">induced</span> by ischemia and reperfusion in rats. Similar results were obtained in dogs with reperfusion-<span class="hlt">induced</span> arrhythmia. In separate experiments to assess the effects of timing of treatment, KR-32570 given 10 min before or at reperfusion in rat models also significantly reduced the myocardial infarct size (40.9% and 46.1%, respectively) compared with vehicle-treated group. In all studies, KR-32570 caused no significant changes in any hemodynamic profiles. Taken together, these results indicate that KR-32570 significantly reduced the myocardial infarction and incidence of arrhythmias <span class="hlt">induced</span> by ischemia and reperfusion in rats and dogs, without affecting hemodynamic profiles. Thus, it could be potentially useful in the prevention and treatment of myocardial injuries and lethal ventricular arrhythmias.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26252014','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26252014"><span id="translatedtitle">Alpha-Particle-<span class="hlt">Induced</span> Complex Chromosome <span class="hlt">Exchanges</span> Transmitted through Extra-Thymic Lymphopoiesis In Vitro Show Evidence of Emerging Genomic Instability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sumption, Natalia; Goodhead, Dudley T; Anderson, Rhona M</p> <p>2015-01-01</p> <p>Human exposure to high-linear energy transfer α-particles includes environmental (e.g. radon gas and its decay progeny), medical (e.g. radiopharmaceuticals) and occupational (nuclear industry) sources. The associated health risks of α-particle exposure for lung cancer are well documented however the risk estimates for leukaemia remain uncertain. To further our understanding of α-particle effects in target cells for leukaemogenesis and also to seek general markers of individual exposure to α-particles, this study assessed the transmission of chromosomal damage initially-<span class="hlt">induced</span> in human haemopoietic stem and progenitor cells after exposure to high-LET α-particles. Cells surviving exposure were differentiated into mature T-cells by extra-thymic T-cell differentiation in vitro. Multiplex fluorescence in situ hybridisation (M-FISH) analysis of naïve T-cell populations showed the occurrence of stable (clonal) complex chromosome aberrations consistent with those that are characteristically <span class="hlt">induced</span> in spherical cells by the traversal of a single α-particle track. Additionally, complex chromosome <span class="hlt">exchanges</span> were observed in the progeny of irradiated mature T-cell populations. In addition to this, newly arising de novo chromosome aberrations were detected in cells which possessed clonal markers of α-particle exposure and also in cells which did not show any evidence of previous exposure, suggesting ongoing genomic instability in these populations. Our findings support the usefulness and reliability of employing complex chromosome <span class="hlt">exchanges</span> as indicators of past or ongoing exposure to high-LET radiation and demonstrate the potential applicability to evaluate health risks associated with α-particle exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4529306','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4529306"><span id="translatedtitle">Alpha-Particle-<span class="hlt">Induced</span> Complex Chromosome <span class="hlt">Exchanges</span> Transmitted through Extra-Thymic Lymphopoiesis In Vitro Show Evidence of Emerging Genomic Instability</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sumption, Natalia; Goodhead, Dudley T.; Anderson, Rhona M.</p> <p>2015-01-01</p> <p>Human exposure to high-linear energy transfer α-particles includes environmental (e.g. radon gas and its decay progeny), medical (e.g. radiopharmaceuticals) and occupational (nuclear industry) sources. The associated health risks of α-particle exposure for lung cancer are well documented however the risk estimates for leukaemia remain uncertain. To further our understanding of α-particle effects in target cells for leukaemogenesis and also to seek general markers of individual exposure to α-particles, this study assessed the transmission of chromosomal damage initially-<span class="hlt">induced</span> in human haemopoietic stem and progenitor cells after exposure to high-LET α-particles. Cells surviving exposure were differentiated into mature T-cells by extra-thymic T-cell differentiation in vitro. Multiplex fluorescence in situ hybridisation (M-FISH) analysis of naïve T-cell populations showed the occurrence of stable (clonal) complex chromosome aberrations consistent with those that are characteristically <span class="hlt">induced</span> in spherical cells by the traversal of a single α-particle track. Additionally, complex chromosome <span class="hlt">exchanges</span> were observed in the progeny of irradiated mature T-cell populations. In addition to this, newly arising de novo chromosome aberrations were detected in cells which possessed clonal markers of α-particle exposure and also in cells which did not show any evidence of previous exposure, suggesting ongoing genomic instability in these populations. Our findings support the usefulness and reliability of employing complex chromosome <span class="hlt">exchanges</span> as indicators of past or ongoing exposure to high-LET radiation and demonstrate the potential applicability to evaluate health risks associated with α-particle exposure. PMID:26252014</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9249926','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9249926"><span id="translatedtitle">Analysis of cytogenetic effects and DNA adduct formation <span class="hlt">induced</span> by safrole in Chinese hamster lung cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daimon, H; Sawada, S; Asakura, S; Sagami, F</p> <p>1997-01-01</p> <p>Safrole (1-allyl-3,4-methylenedioxybenzene) was tested for its ability to <span class="hlt">induce</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) and chromosomal aberrations (CAs) and to form DNA adducts in Chinese hamster lung (CHL) cells, in order to investigate the relationship between cytogenetic effects and DNA adduct formation under the same treatment conditions. The cells were treated with 0.025-0.2 mg/ml safrole in the presence or absence of rat liver postmitochondrial supernatant fraction (S9). Safrole <span class="hlt">induced</span> significant SCEs and CAs dose-dependently in the presence of S9. SCEs ranged in number from 15.6 to 21.1 SCEs/cell and CAs were observed in 4-37% of cells. Using the 32P-postlabeling assay, two major and two minor safrole-DNA adducts were detected in DNA digests obtained from CHL cells in the presence of S9. The levels of total DNA adducts ranged from 1.3 to 22.8 adducts/10(7) nucleotides. The two major adducts were shown to be guanine derivatives since these adducts comigrated on polyethylenimine plates with the adducts produced by the reaction of safrole with 2'-deoxyguanosine 3'-monophosphate. A correlation was seen between DNA adducts and SCEs or CAs. Neither induction of SCEs and CAs nor formation of DNA adducts was observed in the absence of S9. These findings suggest that SCEs and CAs <span class="hlt">induced</span> by safrole result from covalent DNA modification metabolically activated by S9 in cultured cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22402585','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22402585"><span id="translatedtitle">Comprehensive study of Al-<span class="hlt">induced</span> layer-<span class="hlt">exchange</span> growth for orientation-controlled Si crystals on SiO{sub 2} substrates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kurosawa, Masashi; Sadoh, Taizoh; Miyao, Masanobu</p> <p>2014-11-07</p> <p>Orientation-controlled crystalline Si films on insulating substrates are strongly required to achieve high-performance thin-film devices for next-generation electronics. We have comprehensively investigated the layer-<span class="hlt">exchange</span> kinetics of Al-<span class="hlt">induced</span> crystallization (AIC) in stacked structures, i.e., amorphous-Si/Al-oxide/Al/SiO{sub 2}-substrates, as a function of the air-exposure time of Al surfaces (t{sub air}: 0–24 h) to form Al-oxide interface-layers, the thickness of Al and Si layers (d{sub Al,} d{sub Si}: 50–200 nm), the annealing temperature (450–500 °C), and the annealing time (0–50 h). It has been clarified that longer t{sub air} (>60 min) and/or thinner d{sub Al} and d{sub Si} (<50 nm) lead to the (111) oriented growth; in contrast, shorter t{sub air} (<60 min) and/or thicker d{sub Al} and d{sub Si} (>100 nm) lead to the (100) oriented growth. No correlation between the annealing temperature and the crystal orientation is observed. Detailed analysis reveals that the layer-<span class="hlt">exchange</span> kinetics are dominated by “supply-limited” processing, i.e., diffusion of Si atoms into Al layers through Al-oxide layer. Based on the growth rate dependent Si concentration profiles in Al layers, and the free-energy of Si at Al-oxide/Al or Al/SiO{sub 2} interfaces, a comprehensive model for layer-<span class="hlt">exchange</span> growth is proposed. This well explains the experimental results of not only Si-AIC but also another material system such as gold-<span class="hlt">induced</span> crystallization of Ge. In this way, a growth technique achieving the orientation-controlled Si crystals on insulating substrates is established from both technological and scientific points of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115g5301I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115g5301I"><span id="translatedtitle">Effective Hamiltonians for Rapidly Driven Many-Body Lattice Systems: <span class="hlt">Induced</span> <span class="hlt">Exchange</span> Interactions and Density-Dependent Hoppings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Itin, A. P.; Katsnelson, M. I.</p> <p>2015-08-01</p> <p>We consider 1D lattices described by Hubbard or Bose-Hubbard models, in the presence of periodic high-frequency perturbations, such as uniform ac force or modulation of hopping coefficients. Effective Hamiltonians for interacting particles are derived using an averaging method resembling classical canonical perturbation theory. As is known, a high-frequency force may renormalize hopping coefficients, causing interesting phenomena such as coherent destruction of tunneling and creation of artificial gauge fields. We find explicitly additional corrections to the effective Hamiltonians due to interactions, corresponding to nontrivial processes such as single-particle density-dependent tunneling, correlated pair hoppings, nearest neighbor interactions, etc. Some of these processes arise also in multiband lattice models, and are capable of giving rise to a rich variety of quantum phases. The apparent contradiction with other methods, e.g., Floquet-Magnus expansion, is explained. The results may be useful for designing effective Hamiltonian models in experiments with ultracold atoms, as well as in the field of ultrafast nonequilibrium magnetism. An example of manipulating <span class="hlt">exchange</span> interaction in a Mott-Hubbard insulator is considered, where our corrections play an essential role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJS..224...31M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJS..224...31M"><span id="translatedtitle">Charge <span class="hlt">Exchange-induced</span> X-Ray Emission of Fe xxv and Fe xxvI via a Streamlined Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mullen, P. D.; Cumbee, R. S.; Lyons, D.; Stancil, P. C.</p> <p>2016-06-01</p> <p>Charge <span class="hlt">exchange</span> (CX) is an important process for the modeling of X-ray spectra obtained by the Chandra, XMM-Newton, and Suzaku X-ray observatories, as well as the anticipated Astro-H mission. The understanding of the observed X-ray spectra produced by many astrophysical environments is hindered by the current incompleteness of available atomic and molecular data—especially for CX. Here, we implement a streamlined program set that applies quantum defect methods and the Landau-Zener theory to generate total, n-resolved, and n{\\ell }S-resolved cross sections for any given projectile ion/target CX collision. By using these data in a cascade model for X-ray emission, theoretical spectra for such systems can be predicted. With these techniques, Fe25+ and Fe26+ CX collisions with H, He, H2, N2, H2O, and CO are studied for single-electron capture (SEC). These systems have been selected because they illustrate computational difficulties for high projectile charges. Furthermore, Fe xxv and Fe xxvi emission lines have been detected in the Galactic center and Galactic ridge. Theoretical X-ray spectra for these collision systems are compared to experimental data generated by an electron-beam ion trap study. Several ℓ-distribution models have been tested for Fe25+ and Fe26+ SEC. Such analyses suggests that commonly used ℓ-distribution models struggle to accurately reflect the true distribution of electron capture as understood by more advanced theoretical methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961294','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961294"><span id="translatedtitle">Biotic Control of Surface pH and Evidence of Light-<span class="hlt">Induced</span> H+ Pumping and Ca2+-H+ <span class="hlt">Exchange</span> in a Tropical Crustose Coralline Alga</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hofmann, Laurie C.; Koch, Marguerite; de Beer, Dirk</p> <p>2016-01-01</p> <p>Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA) using microsensors. We measured pH, oxygen (O2), and calcium (Ca2+) dynamics and fluxes at the thallus surface under ambient (8.1) and low (7.8) seawater pH (pHSW) and across a range of irradiances. Acetazolamide (AZ) was used to inhibit extracellular carbonic anhydrase (CAext), which mediates hydrolysis of HCO3-, and 4,4′ diisothiocyanatostilbene-2,2′-disulphonate (DIDS) that blocks direct HCO3- uptake by anion <span class="hlt">exchange</span> transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ <span class="hlt">exchange</span>. Rapid light-<span class="hlt">induced</span> H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-<span class="hlt">inducible</span> H+ pumps. Our results suggest that complex light-<span class="hlt">induced</span> ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA. PMID:27459463</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27459463','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27459463"><span id="translatedtitle">Biotic Control of Surface pH and Evidence of Light-<span class="hlt">Induced</span> H+ Pumping and Ca2+-H+ <span class="hlt">Exchange</span> in a Tropical Crustose Coralline Alga.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hofmann, Laurie C; Koch, Marguerite; de Beer, Dirk</p> <p>2016-01-01</p> <p>Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA) using microsensors. We measured pH, oxygen (O2), and calcium (Ca2+) dynamics and fluxes at the thallus surface under ambient (8.1) and low (7.8) seawater pH (pHSW) and across a range of irradiances. Acetazolamide (AZ) was used to inhibit extracellular carbonic anhydrase (CAext), which mediates hydrolysis of HCO3-, and 4,4' diisothiocyanatostilbene-2,2'-disulphonate (DIDS) that blocks direct HCO3- uptake by anion <span class="hlt">exchange</span> transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ <span class="hlt">exchange</span>. Rapid light-<span class="hlt">induced</span> H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-<span class="hlt">inducible</span> H+ pumps. Our results suggest that complex light-<span class="hlt">induced</span> ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA. PMID:27459463</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17102636','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17102636"><span id="translatedtitle">Intersection between the regulators of sister <span class="hlt">chromatid</span> cohesion establishment and maintenance in budding yeast indicates a multi-step mechanism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noble, Daniel; Kenna, Margaret A; Dix, Melissa; Skibbens, Robert V; Unal, Elçin; Guacci, Vincent</p> <p>2006-11-01</p> <p>Sister <span class="hlt">chromatid</span> cohesion is established during S phase and maintained until anaphase. The cohesin complex (Mcd1p/Scc1p, Smc1p, Smc3p Irr1p/Scc3p in budding yeast) serves a structural role as it is required at all times when cohesion exists. Pds5p colocalizes temporally and spatially with cohesin on chromosomes but is thought to serve as a regulator of cohesion maintenance during mitosis. In contrast, Ctf7p/Eco1p is required during S phase for establishment but is not required during mitosis. Here we provide genetic and biochemical evidence that the pathways of cohesion establishment and maintenance are intimately linked. Our results show that mutants in ctf7 and pds5 are synthetically lethal. Moreover, over-expression of either CTF7 or PDS5 exhibits reciprocal suppression of the other mutant's temperature sensitivity. The suppression by CTF7 is specific for pds5 mutants as CTF7 over-expression increases the temperature sensitivity of an mcd1 mutant but has no effect on smc1 or smc3 mutants. Three additional findings provide new insights into the process of cohesion establishment. First, over-expression of ctf7 alleles deficient in acetylase activity exhibit significantly reduced suppression of the pds5 mutant but exacerbated toxicity to the mcd1 mutant. Second, using chromosome spreads and chromatin immuno-precipitation, we find either cohesin complex or Pds5p chromosomal localization is altered in ctf7 mutants. Finally, biochemical analysis reveals that Ctf7p and Pds5p coimmunoprecipitate, which physically links these regulators of cohesion establishment and maintenance. We propose a model whereby Ctf7p and Pds5p cooperate to facilitate efficient establishment by mediating changes in cohesin complex on chromosomes after its deposition. PMID:17102636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18459737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18459737"><span id="translatedtitle">Nonuniform isotope patterns produced by collision-<span class="hlt">induced</span> dissociation of homogeneously labeled ubiquitin: implications for spatially resolved hydrogen/deuterium <span class="hlt">exchange</span> ESI-MS studies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferguson, Peter L; Konermann, Lars</p> <p>2008-06-01</p> <p>There is an ongoing debate whether collision-<span class="hlt">induced</span> dissociation (CID) of electrosprayed proteins after solution-phase hydrogen/deuterium <span class="hlt">exchange</span> (HDX) is a viable approach for determining spatially resolved deuteration patterns. This work explores the use of two methods, source-CID and hexapole tandem mass spectrometry (MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer, for measuring the fragment deuteration levels of regioselectively labeled ubiquitin. Both methods reveal that b-ions exhibit HDX levels significantly below that of the intact protein, whereas several y'' fragments are labeled to a much greater extent. These results are consistent with earlier source-CID data (Akashi, S.; Naito, Y.; Takio, K. Anal. Chem. 1999, 71, 4974-4980). However, the measured b-ion deuteration levels are in disagreement with the known solution-phase behavior of ubiquitin. Partial agreement is observed for y''-ions. Control experiments on homogeneously labeled ubiquitin (having the same average deuteration level at every <span class="hlt">exchangeable</span> site) result in highly nonuniform fragment HDX levels. In particular, b-ions exhibit deuteration levels significantly below that of intact ubiquitin, thereby mimicking the behavior seen for the regioselectively labeled protein. This effect is likely caused by isotope fractionation during collisional activation, facilitated by the high mobility of charge carriers (scrambling) in the gas phase. The observation that the b-ion labeling behavior is largely independent of the spatial isotope distribution within solution-phase ubiquitin invalidates these ions as reporters of the protein deuteration pattern. This work questions the common practice of interpreting any nonuniformities in fragment deuteration as being indicative of regioselective solution-phase labeling. Artifactual deuterium enrichment or depletion during collisional activation may have contributed to the current lack of consensus as to whether HDX/CID represents a potentially</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4766842','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4766842"><span id="translatedtitle">HEAT <span class="hlt">EXCHANGER</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fox, T.H. III; Richey, T. Jr.; Winders, G.R.</p> <p>1962-10-23</p> <p>A heat <span class="hlt">exchanger</span> is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The <span class="hlt">exchanger</span> employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4340380','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4340380"><span id="translatedtitle">Involvement of the Na+/Ca2+ <span class="hlt">exchanger</span> isoform 1 (NCX1) in Neuronal Growth Factor (NGF)-<span class="hlt">induced</span> Neuronal Differentiation through Ca2+-dependent Akt Phosphorylation*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Secondo, Agnese; Esposito, Alba; Sirabella, Rossana; Boscia, Francesca; Pannaccione, Anna; Molinaro, Pasquale; Cantile, Maria; Ciccone, Roselia; Sisalli, Maria Josè; Scorziello, Antonella; Di Renzo, Gianfranco; Annunziato, Lucio</p> <p>2015-01-01</p> <p>NGF <span class="hlt">induces</span> neuronal differentiation by modulating [Ca2+]i. However, the role of the three isoforms of the main Ca2+-extruding system, the Na+/Ca2+ <span class="hlt">exchanger</span> (NCX), in NGF-<span class="hlt">induced</span> differentiation remains unexplored. We investigated whether NCX1, NCX2, and NCX3 isoforms could play a relevant role in neuronal differentiation through the modulation of [Ca2+]i and the Akt pathway. NGF caused progressive neurite elongation; a significant increase of the well known marker of growth cones, GAP-43; and an enhancement of endoplasmic reticulum (ER) Ca2+ content and of Akt phosphorylation through an early activation of ERK1/2. Interestingly, during NGF-<span class="hlt">induced</span> differentiation, the NCX1 protein level increased, NCX3 decreased, and NCX2 remained unaffected. At the same time, NCX total activity increased. Moreover, NCX1 colocalized and coimmunoprecipitated with GAP-43, and NCX1 silencing prevented NGF-<span class="hlt">induced</span> effects on GAP-43 expression, Akt phosphorylation, and neurite outgrowth. On the other hand, the overexpression of its neuronal splicing isoform, NCX1.4, even in the absence of NGF, <span class="hlt">induced</span> an increase in Akt phosphorylation and GAP-43 protein expression. Interestingly, tetrodotoxin-sensitive Na+ currents and 1,3-benzenedicarboxylic acid, 4,4′-[1,4,10-trioxa-7,13-diazacyclopentadecane-7,13-diylbis(5-methoxy-6,12-benzofurandiyl)]bis-, tetrakis[(acetyloxy)methyl] ester-detected [Na+]i significantly increased in cells overexpressing NCX1.4 as well as ER Ca2+ content. This latter effect was prevented by tetrodotoxin. Furthermore, either the [Ca2+]i chelator(1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) (BAPTA-AM) or the PI3K inhibitor LY 294002 prevented Akt phosphorylation and GAP-43 protein expression rise in NCX1.4 overexpressing cells. Moreover, in primary cortical neurons, NCX1 silencing prevented Akt phosphorylation, GAP-43 and MAP2 overexpression, and neurite elongation. Collectively, these data show that NCX1 participates in neuronal differentiation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24911448','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24911448"><span id="translatedtitle">Optically <span class="hlt">induced</span> dielectropheresis sorting with automated medium <span class="hlt">exchange</span> in an integrated optofluidic device resulting in higher cell viability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Gwo-Bin; Wu, Huan-Chun; Yang, Po-Fu; Mai, John D</p> <p>2014-08-01</p> <p>We demonstrated the integration of a microfluidic device with an optically <span class="hlt">induced</span> dielectrophoresis (ODEP) device such that the critical medium replacement process was performed automatically and the cells could be subsequently manipulated by using digitally projected optical images. ODEP has been demonstrated to generate sufficient forces for manipulating particles/cells by projecting a light pattern onto photoconductive materials which creates virtual electrodes. The production of the ODEP force usually requires a medium that has a suitable electrical conductivity and an appropriate dielectric constant. Therefore, a 0.2 M sucrose solution is commonly used. However, this requires a complicated medium replacement process before one is able to manipulate cells. Furthermore, the 0.2 M sucrose solution is not suitable for the long-term viability of cells. In comparison to conventional manual processes, our automated medium replacement process only took 25 minutes. Experimental data showed that there was up to a 96.2% recovery rate for the manipulated cells. More importantly, the survival rate of the cells was greatly enhanced due to this faster automated process. This newly developed microfluidic chip provided a promising platform for the rapid replacement of the cell medium and this was also the first time that an ODEP device was integrated with other active flow control components in a microfluidic device. By improving cell viability after cell manipulation, this design may contribute to the practical integration of ODEP modules into other lab-on-a-chip devices and biomedical applications in the future. PMID:24911448</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25858142','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25858142"><span id="translatedtitle">Light-<span class="hlt">induced</span> plasticity in leaf hydraulics, venation, anatomy, and gas <span class="hlt">exchange</span> in ecologically diverse Hawaiian lobeliads.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scoffoni, Christine; Kunkle, Justin; Pasquet-Kok, Jessica; Vuong, Christine; Patel, Amish J; Montgomery, Rebecca A; Givnish, Thomas J; Sack, Lawren</p> <p>2015-07-01</p> <p>Leaf hydraulic conductance (Kleaf ) quantifies the capacity of a leaf to transport liquid water and is a major constraint on light-saturated stomatal conductance (gs ) and photosynthetic rate (Amax ). Few studies have tested the plasticity of Kleaf and anatomy across growth light environments. These provided conflicting results. The Hawaiian lobeliads are an excellent system to examine plasticity, given the striking diversity in the light regimes they occupy, and their correspondingly wide range of Amax , allowing maximal carbon gain for success in given environments. We measured Kleaf , Amax , gs and leaf anatomical and structural traits, focusing on six species of lobeliads grown in a common garden under two irradiances (300/800 μmol photons m(-2)  s(-1) ). We tested hypotheses for light-<span class="hlt">induced</span> plasticity in each trait based on expectations from optimality. Kleaf , Amax , and gs differed strongly among species. Sun/shade plasticity was observed in Kleaf , Amax, and numerous traits relating to lamina and xylem anatomy, venation, and composition, but gs was not plastic with growth irradiance. Species native to higher irradiance showed greater hydraulic plasticity. Our results demonstrate that a wide set of leaf hydraulic, stomatal, photosynthetic, anatomical, and structural traits tend to shift together during plasticity and adaptation to diverse light regimes, optimizing performance from low to high irradiance. PMID:25858142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20346638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20346638"><span id="translatedtitle">The role of ascorbic acid on titanium dioxide-<span class="hlt">induced</span> genetic damage assessed by the comet assay and cytogenetic tests.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turkez, Hasan</p> <p>2011-07-01</p> <p>Titanium dioxide (TiO(2)) is used in several commercial products such as cosmetics, sunscreen, toothpaste and pharmaceuticals. However, some recent investigations have revealed that titanium particles generate potential harmful effects on the environment and humans. Because of its strong antioxidant activity, ascorbic acid (AA) is admitted to act as an anti-mutagenic agent. The present study was undertaken to investigate the protective effect of AA against TiO(2)-<span class="hlt">induced</span> genotoxicity. Sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE), micronucleus (MN) and the comet assays were used to assess TiO(2)-<span class="hlt">induced</span> genotoxicity and to establish the protective effects of AA. There were significant increases (P<0.05) in both SCE and MN frequencies of cultures treated with TiO(2) as compared to controls. However, co-application of AA (4.87 and 9.73 μM) and TiO(2) resulted in decreases of SCE and MN rates as compared to the group treated with titanium alone. Besides, significant reductions of primary DNA damage (comet assay) were determined when the AA was added to the cell culture medium simultaneously with TiO(2). In conclusion, the preventive role of AA in alleviating TiO(2)-<span class="hlt">induced</span> DNA damage was indicated for the first time in the present study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17521294','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17521294"><span id="translatedtitle">Effects of KR-33028, a novel Na+/H+ <span class="hlt">exchanger</span>-1 inhibitor, on ischemia and reperfusion-<span class="hlt">induced</span> myocardial infarction in rats and dogs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oh, Kwang-Seok; Seo, Ho Won; Yi, Kyu Yang; Lee, Sunkyung; Yoo, Sung-eun; Lee, Byung Ho</p> <p>2007-06-01</p> <p>The present study was performed to evaluate the cardioprotective effects of KR-33028, a novel Na+/H+ <span class="hlt">exchanger</span> subtype 1 (NHE-1) inhibitor, in rat and dog models of coronary artery occlusion and reperfusion. In anesthetized rats subjected to a 45-min coronary occlusion and a 90-min reperfusion, KR-33028 at 5 min before occlusion (i.v. bolus) dose-dependently reduced myocardial infarct size from 58.0% to 46.6%, 40.3%, 39.7%, 33.1%, and 27.8% for 0.03, 0.1, 0.3, 1.0, and 3.0 mg/kg respectively (P < 0.05). In anesthetized beagle dogs that underwent a 1.0-h occlusion followed by a 3.0-h reperfusion, KR-33028 (3 mg/kg, i.v. bolus) markedly decreased infarct size from 45.6% in vehicle-treated group to 16.4% (P < 0.05), and reduced the reperfusion-<span class="hlt">induced</span> release in creatine kinase myocardial band isoenzyme (MB), lactate dehydrogenase, troponin-I, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase. In separate experiments to assess the effects of timing of treatment, KR-33028 (1 mg/kg, i.v. bolus) given 10 min before or at reperfusion in rat models also significantly reduced the myocardial infarct size (46.3% and 44.1% respectively) compared with vehicle-treated group. In all studies, KR-33028 caused no significant changes in any hemodynamic profiles. In an isolated rat heart model of hypothermic cardioplegia, KR-33028 (30 mum), which was added to the heart preservation solution (histidin-tryptophan-ketoglutarate) during hypothermic cardioplegic arrest, significantly improved the recovery of left ventricular developed pressure, heart rate and dP/dt(max) after reperfusion. Taken together, these results indicate that KR-33028 significantly reduced the myocardial infarction <span class="hlt">induced</span> by ischemia and reperfusion in rats and dogs, without affecting hemodynamic profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPhD...49L5001D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JPhD...49L5001D&link_type=ABSTRACT"><span id="translatedtitle">Hydrostatic pressure tuned magneto-structural transition and occurrence of pressure <span class="hlt">induced</span> <span class="hlt">exchange</span> bias effect in Mn0.85Fe0.15NiGe alloy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dutta, P.; Pramanick, S.; Das, D.; Chatterjee, S.</p> <p>2016-09-01</p> <p>The magnetic and magneto-functional behavior of a Fe-doped MnNiGe alloy with nominal composition Mn0.85Fe0.15NiGe have been investigated in ambient as well as in high pressure conditions. The alloy undergoes a first order martensitic phase transition (MPT) around 200 K and also shows a large conventional magnetocaloric effect (MCE) ( Δ S∼ -21 J kg‑1 K‑1 for magnetic field (H) changing from 0–50 kOe) around the transition in ambient conditions. The application of external hydrostatic pressure (P) results in a shift in MPT towards the lower temperature and a clear decrease in the saturation moment of the alloy at 5 K. The peak value of MCE is also found to decrease with increasing external P (∼18 J kg‑1 K‑1 decrease in Δ S has been observed for P  =  12.5 kbar). The most interesting observation is the occurrence of the <span class="hlt">exchange</span> bias effect (EBE) on application of external P. The competing ferromagnetic and antiferromagnetic interaction in the presence of external P plays the pivotal role towards the observation of P <span class="hlt">induced</span> EBE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhD...49L5001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhD...49L5001D"><span id="translatedtitle">Hydrostatic pressure tuned magneto-structural transition and occurrence of pressure <span class="hlt">induced</span> <span class="hlt">exchange</span> bias effect in Mn0.85Fe0.15NiGe alloy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dutta, P.; Pramanick, S.; Das, D.; Chatterjee, S.</p> <p>2016-09-01</p> <p>The magnetic and magneto-functional behavior of a Fe-doped MnNiGe alloy with nominal composition Mn0.85Fe0.15NiGe have been investigated in ambient as well as in high pressure conditions. The alloy undergoes a first order martensitic phase transition (MPT) around 200 K and also shows a large conventional magnetocaloric effect (MCE) ( Δ S˜ -21 J kg-1 K-1 for magnetic field (H) changing from 0-50 kOe) around the transition in ambient conditions. The application of external hydrostatic pressure (P) results in a shift in MPT towards the lower temperature and a clear decrease in the saturation moment of the alloy at 5 K. The peak value of MCE is also found to decrease with increasing external P (˜18 J kg-1 K-1 decrease in Δ S has been observed for P  =  12.5 kbar). The most interesting observation is the occurrence of the <span class="hlt">exchange</span> bias effect (EBE) on application of external P. The competing ferromagnetic and antiferromagnetic interaction in the presence of external P plays the pivotal role towards the observation of P <span class="hlt">induced</span> EBE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4709268','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4709268"><span id="translatedtitle">The Rho-guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF governs susceptibility to diet-<span class="hlt">induced</span> obesity and type 2 diabetes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chang, Ying-Ju; Pownall, Scott; Jensen, Thomas E; Mouaaz, Samar; Foltz, Warren; Zhou, Lily; Liadis, Nicole; Woo, Minna; Hao, Zhenyue; Dutt, Previn; Bilan, Philip J; Klip, Amira; Mak, Tak; Stambolic, Vuk</p> <p>2015-01-01</p> <p>Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-<span class="hlt">induced</span> obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies. DOI: http://dx.doi.org/10.7554/eLife.06011.001 PMID:26512886</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5276019','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5276019"><span id="translatedtitle">Heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Drury, C.R.</p> <p>1988-02-02</p> <p>A heat <span class="hlt">exchanger</span> having primary and secondary conduits in heat-<span class="hlt">exchanging</span> relationship is described comprising: at least one serpentine tube having parallel sections connected by reverse bends, the serpentine tube constituting one of the conduits; a group of open-ended tubes disposed adjacent to the parallel sections, the open-ended tubes constituting the other of the conduits, and forming a continuous mass of contacting tubes extending between and surrounding the serpentine tube sections; and means securing the mass of tubes together to form a predetermined cross-section of the entirety of the mass of open-ended tubes and tube sections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=site+AND+hosting&pg=4&id=ED228136','ERIC'); return false;" href="http://eric.ed.gov/?q=site+AND+hosting&pg=4&id=ED228136"><span id="translatedtitle">Manitoba <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Coss, Maurice</p> <p></p> <p>Planning ideas and follow-up activities are described for a reciprocal <span class="hlt">exchange</span> program between groups of 5th and 6th grade students in Manitoba who are "twinned" with another school in the province. Emphasis is on providing learning experiences which help students become familiar with the economic activity in the area, with the local government…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/862437','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/862437"><span id="translatedtitle">Heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wolowodiuk, Walter</p> <p>1976-01-06</p> <p>A heat <span class="hlt">exchanger</span> of the straight tube type in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863465','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863465"><span id="translatedtitle">Heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Daman, Ernest L.; McCallister, Robert A.</p> <p>1979-01-01</p> <p>A heat <span class="hlt">exchanger</span> is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMagR.265...45B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMagR.265...45B"><span id="translatedtitle">Nonadiabatic <span class="hlt">exchange</span> dynamics during adiabatic frequency sweeps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbara, Thomas M.</p> <p>2016-04-01</p> <p>A Bloch equation analysis that includes relaxation and <span class="hlt">exchange</span> effects during an adiabatic frequency swept pulse is presented. For a large class of sweeps, relaxation can be incorporated using simple first order perturbation theory. For anisochronous <span class="hlt">exchange</span>, new expressions are derived for <span class="hlt">exchange</span> augmented rotating frame relaxation. For isochronous <span class="hlt">exchange</span> between sites with distinct relaxation rate constants outside the extreme narrowing limit, simple criteria for adiabatic <span class="hlt">exchange</span> are derived and demonstrate that frequency sweeps commonly in use may not be adiabatic with regard to <span class="hlt">exchange</span> unless the <span class="hlt">exchange</span> rates are much larger than the relaxation rates. Otherwise, accurate assessment of the sensitivity to <span class="hlt">exchange</span> dynamics will require numerical integration of the rate equations. Examples of this situation are given for experimentally relevant parameters believed to hold for in-vivo tissue. These results are of significance in the study of <span class="hlt">exchange</span> <span class="hlt">induced</span> contrast in magnetic resonance imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22526492','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22526492"><span id="translatedtitle">In vitro studies on chemoprotective effect of borax against aflatoxin B1-<span class="hlt">induced</span> genetic damage in human lymphocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turkez, Hasan; Geyikoğlu, Fatime; Dirican, Ebubekir; Tatar, Abdulgani</p> <p>2012-12-01</p> <p>A common dietary contaminant, aflatoxin B1 (AFB1), has been shown to be a potent mutagen and carcinogen in humans and many animal species. Since the eradication of AFB1 contamination in agricultural products has been rare, the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Boron compounds like borax (BX) and boric acid are the major components of industry and their antioxidant role has recently been reported. In the present report, we evaluated the capability of BX to inhibit the rate of micronucleus (MN) and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) formations <span class="hlt">induced</span> by AFB1. There were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with AFB1 (3.12 ppm) as compared to controls. However, co-application of BX (1, 2 and 5 ppm) and AFB1 resulted in decreases of SCE and MN rates as compared to the group treated with AFB1 alone. Borax gave 30-50 % protection against AFB1 <span class="hlt">induced</span> SCEs and MNs. In conclusion, the support of borax was especially useful in aflatoxin-toxicated blood tissue. Thus, the risk on target tissues of AFB1 could be reduced and ensured early recovery from its toxicity. PMID:22526492</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22526492','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22526492"><span id="translatedtitle">In vitro studies on chemoprotective effect of borax against aflatoxin B1-<span class="hlt">induced</span> genetic damage in human lymphocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turkez, Hasan; Geyikoğlu, Fatime; Dirican, Ebubekir; Tatar, Abdulgani</p> <p>2012-12-01</p> <p>A common dietary contaminant, aflatoxin B1 (AFB1), has been shown to be a potent mutagen and carcinogen in humans and many animal species. Since the eradication of AFB1 contamination in agricultural products has been rare, the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Boron compounds like borax (BX) and boric acid are the major components of industry and their antioxidant role has recently been reported. In the present report, we evaluated the capability of BX to inhibit the rate of micronucleus (MN) and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) formations <span class="hlt">induced</span> by AFB1. There were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with AFB1 (3.12 ppm) as compared to controls. However, co-application of BX (1, 2 and 5 ppm) and AFB1 resulted in decreases of SCE and MN rates as compared to the group treated with AFB1 alone. Borax gave 30-50 % protection against AFB1 <span class="hlt">induced</span> SCEs and MNs. In conclusion, the support of borax was especially useful in aflatoxin-toxicated blood tissue. Thus, the risk on target tissues of AFB1 could be reduced and ensured early recovery from its toxicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70032533','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70032533"><span id="translatedtitle">Influence of a thin veneer of low-hydraulic-conductivity sediment on modelled <span class="hlt">exchange</span> between river water and groundwater in response to <span class="hlt">induced</span> infiltration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rosenberry, D.O.; Healy, R.W.</p> <p>2012-01-01</p> <p>A thin layer of fine-grained sediment commonly is deposited at the sediment-water interface of streams and rivers during low-flow conditions, and may hinder <span class="hlt">exchange</span> at the sediment-water interface similar to that observed at many riverbank-filtration (RBF) sites. Results from a numerical groundwater-flow model indicate that a low-permeability veneer reduces the contribution of river water to a pumping well in a riparian aquifer to various degrees, depending on simulated hydraulic gradients, hydrogeological properties, and pumping conditions. Seepage of river water is reduced by 5-10% when a 2-cm thick, low-permeability veneer is present on the bed surface. Increasing thickness of the low-permeability layer to 0??1 m has little effect on distribution of seepage or percentage contribution from the river to the pumping well. A three-orders-of-magnitude reduction in hydraulic conductivity of the veneer is required to reduce seepage from the river to the extent typically associated with clogging at RBF sites. This degree of reduction is much larger than field-measured values that were on the order of a factor of 20-25. Over 90% of seepage occurs within 12 m of the shoreline closest to the pumping well for most simulations. Virtually no seepage occurs through the thalweg near the shoreline opposite the pumping well, although no low-permeability sediment was simulated for the thalweg. These results are relevant to natural settings that favour formation of a substantial, low-permeability sediment veneer, as well as central-pivot irrigation systems, and municipal water supplies where river seepage is <span class="hlt">induced</span> via pumping wells. Published in 2011 by John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25119059','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25119059"><span id="translatedtitle">Novel mechanism of intra‑renal angiotensin II-<span class="hlt">induced</span> sodium/proton <span class="hlt">exchanger</span> 3 expression by losartan in spontaneously hypertensive rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fan, Xiaoqin; Liu, Kaishan; Cui, Wei; Huang, Jiongmei; Wang, Weina; Gao, Yuan</p> <p>2014-11-01</p> <p>The present study aimed to investigate the molecular pharmacodynamic mechanisms of losartan used in the treatment of hypertension. A total of 12 spontaneously hypertensive rats (SHR) were divided randomly into an SHR group treated with saline and LOS group treated with losartan. Six Wistar‑kyoto rats (WKY) were enrolled as the WKY group with saline in the study. The LOS group received 30 mg/kg/day losartan by intragastric injection, while the SHR and WKY were fed the same volume of saline. The dosage was modulated according to the weekly weight. Changes in blood pressure were measured by the indirect tail cuff method. Angiotensin (Ang) II production in the plasma and renal tissue was measured by an immunoradiometric method. Na+/H+ <span class="hlt">exchanger</span> (NHE)3 and serum and glucocorticoid‑<span class="hlt">inducible</span> kinase (SGK)1 were assessed by quantitative polymerase chain reaction (qPCR) and western blot analysis. When compared with the WKY group, the blood pressure of the SHR and LOS groups were higher prior to treatment with losartan. Following two weeks, blood pressure was reduced and the trend continued to decrease over the following six weeks. The plasma and renal tissue levels of Ang II in the SHR and LOS groups were significantly higher than those in the WKY group. NHE3 and SGK1 were increased at the mRNA and protein level in the SHR group, and losartan reduced the expression of both of them. The results suggested that in hypertensive rats, the circular and tissue renin angiotensin systems were activated, and the increased Ang II stimulated the expression of NHE3 and SGK1, which was reduced by losartan. Therefore, the effects of losartan in hypertension may be associated with the Ang II‑SGK1‑NHE3 of intra‑renal tissue.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25178256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25178256"><span id="translatedtitle">Phosphorylation- and nucleotide-binding-<span class="hlt">induced</span> changes to the stability and hydrogen <span class="hlt">exchange</span> patterns of JNK1β1 provide insight into its mechanisms of activation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Owen, Gavin R; Stoychev, Stoyan; Achilonu, Ikechukwu; Dirr, Heini W</p> <p>2014-10-23</p> <p>Many studies have characterized how changes to the stability and internal motions of a protein during activation can contribute to their catalytic function, even when structural changes cannot be observed. Here, unfolding studies and hydrogen-deuterium <span class="hlt">exchange</span> (HX) mass spectrometry were used to investigate the changes to the stability and conformation/conformational dynamics of JNK1β1 <span class="hlt">induced</span> by phosphorylative activation. Equivalent studies were also employed to determine the effects of nucleotide binding on both inactive and active JNK1β1 using the ATP analogue, 5'-adenylyl-imidodiphosphate (AMP-PNP). JNK1β1 phosphorylation alters HX in regions involved in catalysis and substrate binding, changes that can be ascribed to functional modifications in either structure and/or backbone flexibility. Increased HX in the hinge between the N- and C-terminal domains implied that it acquires enhanced flexibility upon phosphorylation that may be a prerequisite for interdomain closure. In combination with the finding that nucleotide binding destabilizes the kinase, the patterns of solvent protection by AMP-PNP were consistent with a novel mode of nucleotide binding to the C-terminal domain of a destabilized and open domain conformation of inactive JNK1β1. Solvent protection by AMP-PNP of both N- and C-terminal domains in active JNK1β1 revealed that the domains close around nucleotide upon phosphorylation, concomitantly stabilizing the kinase. This suggests that phosphorylation activates JNK1β1 in part by increasing hinge flexibility to facilitate interdomain closure and the creation of a functional active site. By uncovering the complex interplay that occurs between nucleotide binding and phosphorylation, we present new insight into the unique mechanisms by which JNK1β1 is regulated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27009277','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27009277"><span id="translatedtitle">Role of Rho kinase and Na+/H+ <span class="hlt">exchange</span> in hypoxia-<span class="hlt">induced</span> pulmonary arterial smooth muscle cell proliferation and migration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walker, Jasmine; Undem, Clark; Yun, Xin; Lade, Julie; Jiang, Haiyang; Shimoda, Larissa A</p> <p>2016-03-01</p> <p>Abnormal proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) are hallmark characteristics of vascular remodeling in pulmonary hypertension <span class="hlt">induced</span> by chronic hypoxia. In this study, we investigated the role of the Na(+)/H(+)<span class="hlt">exchanger</span> (NHE) and alterations in intracellularpH(pHi) homeostasis in meditating increased proliferation and migration inPASMCs isolated from resistance-sized pulmonary arteries from chronically hypoxic rats or from normoxic rats that were exposed to hypoxia ex vivo (1% or 4% O2, 24-96 h). We found thatPASMCs exposed to either in vivo or ex vivo hypoxia exhibited greater proliferative and migratory capacity, elevated pHi, and enhancedNHEactivity. TheNHEinhibitor, ethyl isopropyl amiloride (EIPA), normalized pHiin hypoxicPASMCs and reduced migration by 73% and 45% in cells exposed to in vivo and in vitro hypoxia, respectively. Similarly,EIPAreduced proliferation by 97% and 78% in cells exposed to in vivo and in vitro hypoxia, respectively. We previously demonstrated thatNHEisoform 1 (NHE1) is the predominant isoform expressed inPASMCs. The development of hypoxia-<span class="hlt">induced</span> pulmonary hypertension and alterations inPASMC pHihomeostasis were prevented in mice deficient forNHE1. We found that short-term (24 h) ex vivo hypoxic exposure did not alter the expression ofNHE1, so we tested the role of Rho kinase (ROCK) as a possible means of increasingNHEactivity. In the presence of theROCKinhibitor, Y-27632, we found that pHiandNHEactivity were normalized and migration and proliferation were reduced inPASMCs exposed to either in vivo (by 68% for migration and 22% for proliferation) or ex vivo (by 43% for migration and 17% for proliferation) hypoxia. From these results, we conclude that during hypoxia, activation ofROCKenhancesNHEactivity and promotesPASMCmigration and proliferation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4673635','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4673635"><span id="translatedtitle">Role of the Na+/H+ <span class="hlt">exchanger</span> 3 in angiotensin II-<span class="hlt">induced</span> hypertension in NHE3-deficient mice with transgenic rescue of NHE3 in small intestines</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Xiao C; Shull, Gary E; Miguel-Qin, Elisa; Chen, Fang; Zhuo, Jia L</p> <p>2015-01-01</p> <p>The role of Na+/H+ <span class="hlt">exchanger</span> 3 (NHE3) in the kidney in angiotensin II (ANG II)-<span class="hlt">induced</span> hypertension remains unknown. The present study used global NHE3-deficient mice with transgenic rescue of the Nhe3 gene in small intestines (tgNhe3−/−) to test the hypothesis that genetic deletion of NHE3 selectively in the kidney attenuates ANG II-<span class="hlt">induced</span> hypertension. Six groups of wild-type (tgNhe3+/+) and tgNhe3−/− mice were infused with either vehicle or ANG II (1.5 mg/kg/day, i.p., 2 weeks, or 10 nmol/min, i.v., 30 min), treated with or without losartan (20 mg/kg/day, p.o.) for 2 weeks. Basal systolic blood pressure (SBP) and mean intra-arterial blood pressure (MAP) were significantly lower in tgNhe3−/− mice (P < 0.01). Basal glomerular filtration rate, 24 h urine excretion, urinary Na+ excretion, urinary K+ excretion, and urinary Cl− excretion were significantly lower in tgNhe3−/− mice (P < 0.01). These responses were associated with significantly elevated plasma ANG II and aldosterone levels, and marked upregulation in aquaporin 1, the Na+/HCO3 cotransporter, the α1 subunit isoform of Na+/K+-ATPase, protein kinase Cα, MAP kinases ERK1/2, and glycogen synthase kinase 3 α/β in the renal cortex of tgNhe3−/− mice (P < 0.01). ANG II infusion markedly increased SBP and MAP and renal cortical transporter and signaling proteins in tgNhe3+/+, as expected, but all of these responses to ANG II were attenuated in tgNhe3−/− mice (P < 0.01). These results suggest that NHE3 in the kidney is necessary for maintaining normal blood pressure and fully developing ANG II-dependent hypertension. PMID:26564064</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26564064','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26564064"><span id="translatedtitle">Role of the Na+/H+ <span class="hlt">exchanger</span> 3 in angiotensin II-<span class="hlt">induced</span> hypertension in NHE3-deficient mice with transgenic rescue of NHE3 in small intestines.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiao C; Shull, Gary E; Miguel-Qin, Elisa; Chen, Fang; Zhuo, Jia L</p> <p>2015-11-01</p> <p>The role of Na(+/)H(+) <span class="hlt">exchanger</span> 3 (NHE3) in the kidney in angiotensin II (ANG II)-<span class="hlt">induced</span> hypertension remains unknown. The present study used global NHE3-deficient mice with transgenic rescue of the Nhe3 gene in small intestines (tgNhe3(-/-)) to test the hypothesis that genetic deletion of NHE3 selectively in the kidney attenuates ANG II-<span class="hlt">induced</span> hypertension. Six groups of wild-type (tgNhe3(+/+)) and tgNhe3(-/-) mice were infused with either vehicle or ANG II (1.5 mg/kg/day, i.p., 2 weeks, or 10 nmol/min, i.v., 30 min), treated with or without losartan (20 mg/kg/day, p.o.) for 2 weeks. Basal systolic blood pressure (SBP) and mean intra-arterial blood pressure (MAP) were significantly lower in tgNhe3(-/-) mice (P < 0.01). Basal glomerular filtration rate, 24 h urine excretion, urinary Na(+) excretion, urinary K(+) excretion, and urinary Cl(-) excretion were significantly lower in tgNhe3(-/-) mice (P < 0.01). These responses were associated with significantly elevated plasma ANG II and aldosterone levels, and marked upregulation in aquaporin 1, the Na(+)/HCO3 cotransporter, the α1 subunit isoform of Na(+)/K(+)-ATPase, protein kinase Cα, MAP kinases ERK1/2, and glycogen synthase kinase 3 α/β in the renal cortex of tgNhe3(-/-) mice (P < 0.01). ANG II infusion markedly increased SBP and MAP and renal cortical transporter and signaling proteins in tgNhe3(+/+), as expected, but all of these responses to ANG II were attenuated in tgNhe3(-/-) mice (P < 0.01). These results suggest that NHE3 in the kidney is necessary for maintaining normal blood pressure and fully developing ANG II-dependent hypertension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3810813','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3810813"><span id="translatedtitle"><span class="hlt">Exchange</span> protein activated by cAMP (Epac) <span class="hlt">induces</span> vascular relaxation by activating Ca2+-sensitive K+ channels in rat mesenteric artery</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Roberts, Owain Llŷr; Kamishima, Tomoko; Barrett-Jolley, Richard; Quayle, John M; Dart, Caroline</p> <p>2013-01-01</p> <p>Vasodilator-<span class="hlt">induced</span> elevation of intracellular cyclic AMP (cAMP) is a central mechanism governing arterial relaxation but is incompletely understood due to the diversity of cAMP effectors. Here we investigate the role of the novel cAMP effector <span class="hlt">exchange</span> protein directly activated by cAMP (Epac) in mediating vasorelaxation in rat mesenteric arteries. In myography experiments, the Epac-selective cAMP analogue 8-pCPT-2′-O-Me-cAMP-AM (5 μm, subsequently referred to as 8-pCPT-AM) elicited a 77.6 ± 7.1% relaxation of phenylephrine-contracted arteries over a 5 min period (mean ± SEM; n= 6). 8-pCPT-AM <span class="hlt">induced</span> only a 16.7 ± 2.4% relaxation in arteries pre-contracted with high extracellular K+ over the same time period (n= 10), suggesting that some of Epac's relaxant effect relies upon vascular cell hyperpolarization. This involves Ca2+-sensitive, large-conductance K+ (BKCa) channel opening as iberiotoxin (100 nm) significantly reduced the ability of 8-pCPT-AM to reverse phenylephrine-<span class="hlt">induced</span> contraction (arteries relaxed by only 35.0 ± 8.5% over a 5 min exposure to 8-pCPT-AM, n= 5; P < 0.05). 8-pCPT-AM increased Ca2+ spark frequency in Fluo-4-AM-loaded mesenteric myocytes from 0.045 ± 0.008 to 0.103 ± 0.022 sparks s-1μm-1 (P < 0.05) and reversibly increased both the frequency (0.94 ± 0.25 to 2.30 ± 0.72 s−1) and amplitude (23.9 ± 3.3 to 35.8 ± 7.7 pA) of spontaneous transient outward currents (STOCs) recorded in isolated mesenteric myocytes (n= 7; P < 0.05). 8-pCPT-AM-activated STOCs were sensitive to iberiotoxin (100 nm) and to ryanodine (30 μm). Current clamp recordings of isolated myocytes showed a 7.9 ± 1.0 mV (n= 10) hyperpolarization in response to 8-pCPT-AM that was sensitive to iberiotoxin (n= 5). Endothelial disruption suppressed 8-pCPT-AM-mediated relaxation in phenylephrine-contracted arteries (24.8 ± 4.9% relaxation after 5 min of exposure, n= 5; P < 0.05), as did apamin and TRAM-34, blockers of Ca2+-sensitive, small- and intermediate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23959673','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23959673"><span id="translatedtitle"><span class="hlt">Exchange</span> protein activated by cAMP (Epac) <span class="hlt">induces</span> vascular relaxation by activating Ca2+-sensitive K+ channels in rat mesenteric artery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roberts, Owain Llŷr; Kamishima, Tomoko; Barrett-Jolley, Richard; Quayle, John M; Dart, Caroline</p> <p>2013-10-15</p> <p>Vasodilator-<span class="hlt">induced</span> elevation of intracellular cyclic AMP (cAMP) is a central mechanism governing arterial relaxation but is incompletely understood due to the diversity of cAMP effectors. Here we investigate the role of the novel cAMP effector <span class="hlt">exchange</span> protein directly activated by cAMP (Epac) in mediating vasorelaxation in rat mesenteric arteries. In myography experiments, the Epac-selective cAMP analogue 8-pCPT-2-O-Me-cAMP-AM (5 μM, subsequently referred to as 8-pCPT-AM) elicited a 77.6 ± 7.1% relaxation of phenylephrine-contracted arteries over a 5 min period (mean ± SEM; n = 6). 8-pCPT-AM <span class="hlt">induced</span> only a 16.7 ± 2.4% relaxation in arteries pre-contracted with high extracellular K(+) over the same time period (n = 10), suggesting that some of Epac's relaxant effect relies upon vascular cell hyperpolarization. This involves Ca(2+)-sensitive, large-conductance K(+) (BK(Ca)) channel opening as iberiotoxin (100 nM) significantly reduced the ability of 8-pCPT-AM to reverse phenylephrine-<span class="hlt">induced</span> contraction (arteries relaxed by only 35.0 ± 8.5% over a 5 min exposure to 8-pCPT-AM, n = 5; P < 0.05). 8-pCPT-AM increased Ca(2+) spark frequency in Fluo-4-AM-loaded mesenteric myocytes from 0.045 ± 0.008 to 0.103 ± 0.022 sparks s(-1) μm(-1) (P < 0.05) and reversibly increased both the frequency (0.94 ± 0.25 to 2.30 ± 0.72 s(-1)) and amplitude (23.9 ± 3.3 to 35.8 ± 7.7 pA) of spontaneous transient outward currents (STOCs) recorded in isolated mesenteric myocytes (n = 7; P < 0.05). 8-pCPT-AM-activated STOCs were sensitive to iberiotoxin (100 nM) and to ryanodine (30 μM). Current clamp recordings of isolated myocytes showed a 7.9 ± 1.0 mV (n = 10) hyperpolarization in response to 8-pCPT-AM that was sensitive to iberiotoxin (n = 5). Endothelial disruption suppressed 8-pCPT-AM-mediated relaxation in phenylephrine-contracted arteries (24.8 ± 4.9% relaxation after 5 min of exposure, n = 5; P < 0.05), as did apamin and TRAM-34, blockers of Ca(2+)-sensitive, small- and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6030662','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6030662"><span id="translatedtitle">Conformational states of the nicotinic acetylcholine receptor from Torpedo californica <span class="hlt">induced</span> by the binding of agonists, antagonists, and local anesthetics. Equilibrium measurements using tritium-hydrogen <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McCarthy, M.P.; Stroud, R.M.</p> <p>1989-01-10</p> <p>The tritium-hydrogen <span class="hlt">exchange</span> kinetics of Torpedo californica AChR, in native membrane vesicles at pH 7.4 and 0 degrees C, have been analyzed in the presence of agonists, partial agonists, local anesthetics, and competitive antagonists. The agonists carbamylcholine (10 microM-1 mM) and suberyldicholine (10 microM) and the partial agonists decamethonium (25 microM and 1 mM) and hexamethonium (1 mM) have no effect on the <span class="hlt">exchange</span> kinetics, although at lower concentration carbamylcholine may slightly accelerate <span class="hlt">exchange</span>. Nondesensitizing local anesthetics do affect the <span class="hlt">exchange</span> behavior, dependent on concentration. Procaine at 500 microM moderately retards <span class="hlt">exchange</span> while procaine at 10 mM and tetracaine at 5 mM slightly accelerate <span class="hlt">exchange</span>. The competitive antagonist alpha-bungarotoxin retards <span class="hlt">exchange</span> significantly, as does d-tubocurarine although to a lesser extent. These results suggest that the resting and desensitized conformations of the AChR are very similar in overall solvent accessibility and that at lower concentrations noncompetitive blockers such as procaine may stabilize a less solvent-accessible state of the AChR. The competitive antagonists alpha-bungarotoxin and d-tubocurare also stabilize a dynamically restricted, less solvent-accessible conformation of the acetylcholine receptor, demonstrating that a large conformational change accompanies binding of these toxins. Any change in conformation which may accompany desensitization is very different from these effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9804941','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9804941"><span id="translatedtitle">In vivo and in vitro antigenotoxic effect of nordihydroguaiaretic acid against SCEs <span class="hlt">induced</span> by methyl methanesulfonate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Madrigal-Bujaidar, E; Díaz Barriga, S; Cassani, M; Márquez, P; Revuelta, P</p> <p>1998-11-01</p> <p>Nordihydroguaiaretic acid (NDGA) is a phenolic lignan which has shown to cause a variety of actions potentially useful for human health; therefore, in this investigation we determined its capacity for inhibiting the rate of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) <span class="hlt">induced</span> by methyl methanesulfonate (MMS). We tested the effect of 0.25, 0.50, 1.0, and 2.0 microM of NDGA on the damage exerted by 55 microM of MMS. Cultured human lymphocytes from two female donors were used for the experiment. The best result concerning its modulatory action was obtained with 1.0 microM of NDGA; with this dose the mean inhibitory index including both donors reached 68.2%. The values obtained for the mitotic and proliferative indexes were not significantly modified with respect to the basal data. We also used the mouse bone marrow in vivo system to evaluate the inhibitory effect of the chemical. In this study we tested 1.0, 6.0, and 11.0 mg/kg of NDGA intraperitoneally (i.p.) administered 1 h before an i.p. injection of MMS (40 mg/kg). The best inhibitory index in this model corresponded to the dose of 11 mg/kg of NDGA (86.9%). The mitotic index and the average generation time showed no significant variation with respect to the control data. Our study established that NDGA produces antigenotoxic action in mammalian cells in vitro and in vivo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872126','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872126"><span id="translatedtitle">Mechanistic insight into cadmium-<span class="hlt">induced</span> inactivation of the Bloom protein</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qin, Wei; Bazeille, Nicolas; Henry, Etienne; Zhang, Bo; Deprez, Eric; Xi, Xu-Guang</p> <p>2016-01-01</p> <p>Cadmium is a toxic metal that inactivates DNA-repair proteins via multiple mechanisms, including zinc substitution. In this study, we investigated the effect of Cd2+ on the Bloom protein (BLM), a DNA-repair helicase carrying a zinc-binding domain (ZBD) and playing a critical role to ensure genomic stability. One characteristics of BLM-deficient cells is the elevated rate of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, a phenomenon that is also <span class="hlt">induced</span> by Cd2+. Here, we show that Cd2+ strongly inhibits both ATPase and helicase activities of BLM. Cd2+ primarily prevents BLM-DNA interaction via its binding to sulfhydryl groups of solvent-exposed cysteine residues and, concomitantly, promotes the formation of large BLM multimers/aggregates. In contrast to previously described Cd2+ effects on other zinc-containing DNA-repair proteins, the ZBD appears to play a minor role in the Cd2+-mediated inhibition. While the Cd2+-dependent formation of inactive multimers and the defect of DNA-binding were fully reversible upon addition of EDTA, the inhibition of the DNA unwinding activity was not counteracted by EDTA, indicating another mechanism of inhibition by Cd2+ relative to the targeting of a catalytic residue. Altogether, our results provide new clues for understanding the mechanism behind the ZBD-independent inactivation of BLM by Cd2+ leading to accumulation of DNA double-strand breaks. PMID:27194376</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22416738','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22416738"><span id="translatedtitle">WRNIP1 functions upstream of DNA polymerase η in the UV-<span class="hlt">induced</span> DNA damage response</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yoshimura, Akari; Kobayashi, Yume; Tada, Shusuke; Seki, Masayuki; Enomoto, Takemi</p> <p>2014-09-12</p> <p>Highlights: • The UV sensitivity of POLH{sup −/−} cells was suppressed by disruption of WRNIP1. • In WRNIP1{sup −/−/−}/POLH{sup −/−} cells, mutation frequencies and SCE after irradiation reduced. • WRNIP1 defect recovered rate of fork progression after irradiation in POLH{sup −/−} cells. • WRNIP1 functions upstream of Polη in the translesion DNA synthesis pathway. - Abstract: WRNIP1 (WRN-interacting protein 1) was first identified as a factor that interacts with WRN, the protein that is defective in Werner syndrome (WS). WRNIP1 associates with DNA polymerase η (Polη), but the biological significance of this interaction remains unknown. In this study, we analyzed the functional interaction between WRNIP1 and Polη by generating knockouts of both genes in DT40 chicken cells. Disruption of WRNIP1 in Polη-disrupted (POLH{sup −/−}) cells suppressed the phenotypes associated with the loss of Polη: sensitivity to ultraviolet light (UV), delayed repair of cyclobutane pyrimidine dimers (CPD), elevated frequency of mutation, elevated levels of UV-<span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE), and reduced rate of fork progression after UV irradiation. These results suggest that WRNIP1 functions upstream of Polη in the response to UV irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5035082','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5035082"><span id="translatedtitle">Drosophila TDP-43 RNA-Binding Protein Facilitates Association of Sister <span class="hlt">Chromatid</span> Cohesion Proteins with Genes, Enhancers and Polycomb Response Elements</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Misulovin, Ziva; Gause, Maria; Rickels, Ryan A; Shilatifard, Ali</p> <p>2016-01-01</p> <p>The cohesin protein complex mediates sister <span class="hlt">chromatid</span> cohesion and participates in transcriptional control of genes that regulate growth and development. Substantial reduction of cohesin activity alters transcription of many genes without disrupting chromosome segregation. Drosophila Nipped-B protein loads cohesin onto chromosomes, and together Nipped-B and cohesin occupy essentially all active transcriptional enhancers and a large fraction of active genes. It is unknown why some active genes bind high levels of cohesin and some do not. Here we show that the TBPH and Lark RNA-binding proteins influence association of Nipped-B and cohesin with genes and gene regulatory sequences. In vitro, TBPH and Lark proteins specifically bind RNAs produced by genes occupied by Nipped-B and cohesin. By genomic chromatin immunoprecipitation these RNA-binding proteins also bind to chromosomes at cohesin-binding genes, enhancers, and Polycomb response elements (PREs). RNAi depletion reveals that TBPH facilitates association of Nipped-B and cohesin with genes and regulatory sequences. Lark reduces binding of Nipped-B and cohesin at many promoters and aids their association with several large enhancers. Conversely, Nipped-B facilitates TBPH and Lark association with genes and regulatory sequences, and interacts with TBPH and Lark in affinity chromatography and immunoprecipitation experiments. Blocking transcription does not ablate binding of Nipped-B and the RNA-binding proteins to chromosomes, indicating transcription is not required to maintain binding once established. These findings demonstrate that RNA-binding proteins help govern association of sister <span class="hlt">chromatid</span> cohesion proteins with genes and enhancers. PMID:27662615</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16595588','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16595588"><span id="translatedtitle">Genotoxicity and endoreduplication <span class="hlt">inducing</span> activity of the food flavouring eugenol.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maralhas, Alexandra; Monteiro, Ana; Martins, Célia; Kranendonk, Michel; Laires, António; Rueff, José; Rodrigues, António S</p> <p>2006-05-01</p> <p>Eugenol (1-allyl-3-methoxy-4-hydroxybenzene; CAS No. 97-53-0), a compound extracted from clove oil and marjoram, is widely used as a food flavouring substance and is present in spices such as basil, cinnamon and nutmeg. It is also used in dentistry as an antiseptic and analgesic. Structural similarities with the class IIB IARC carcinogen safrole raises questions on its putative carcinogenicity. We evaluated the genotoxicity of eugenol in V79 cells using chromosomal aberrations (CAs), with and without rat liver biotransformation (S9). Eugenol <span class="hlt">induced</span> CAs, with significant increases (3.5% aberrant cells) at 2500 microM, demonstrating cytotoxicity at higher doses. S9 increased the induction of CAs in a dose-dependent manner to 15% at 2500 microM, with a high frequency of <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. In particular, an increase of endoreduplicated cells was observed, from 0% at control levels to 2.3 and 5% at 2000 microM, without and with S9, respectively. Since endoreduplication has been linked to inhibition of topoisomerase II, the topoisomerase II inhibitor ICRF-193 was used as a control <span class="hlt">inducer</span> of endoreduplication (0.1-0.5 microM), increasing the number of endoreduplicated cells from 0% (control) to 3.5% (0.5 microM). S9 did not influence endoreduplication by ICRF-193. Both eugenol and ICRF-193 were also assayed for inhibition of topoisomerase II, and both showed a dose-dependent inhibitory effect, with ICRF-193 being a more potent inhibitor. Our results confirm that eugenol is genotoxic and raises the possibility of it having topoisomerase II inhibiting activity. PMID:16595588</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/3311154','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3311154"><span id="translatedtitle">Interdependence of coenzyme-<span class="hlt">induced</span> conformational work and binding potential in yeast alcohol and porcine heart lactate dehydrogenases: a hydrogen-deuterium <span class="hlt">exchange</span> study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Weck, Z; Pande, J; Kägi, J H</p> <p>1987-07-28</p> <p>Binding of NAD coenzymes to yeast alcohol dehydrogenase (YADH) and porcine heart lactate dehydrogenase (PHLDH) was studied by hydrogen-deuterium <span class="hlt">exchange</span> with the infrared technique. Conformational changes in the enzymes specific to the coenzymes and their fragments were observed, and the pH dependence of the <span class="hlt">exchange</span> reaction shows that it conforms to the EX-2 scheme. In both YADH and PHLDH the magnitude of the conformational change of measured by <span class="hlt">exchange</span> retardation is considerably larger for NAD+ than for NADH. Studies with coenzyme fragments like ADP-ribose, ADP, and AMP also highlight the lack of rigorous correlation between structural features such as charge and size and their influence on <span class="hlt">exchange</span> behavior. Ternary complexes such as YADH-NAD+-pyrazole, PHLDH-NAD+-oxalate, and PHLDH-NADH-oxamate, which mimic the transition state, have a significantly more pronounced effect on <span class="hlt">exchange</span> rates than the corresponding binary complexes. The outstanding feature of this study is the demonstration that in the binary enzyme-coenzyme complexes the more loosely bound NAD+ is more effective in retarding <span class="hlt">exchange</span> than the more firmly bound NADH. These differences are attributed to the unequal structural constraints exerted by the two coenzymes upon the enzymes, which translate to unequal expenditure of transconformational work in the formation of the two complexes. The opposing variation in the free energy of binding and the transconformational work expended can be viewed as an unequal partitioning of the net free energy gain resulting from the protein-ligand interaction into a binding term and that required for conformational change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1011401','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1011401"><span id="translatedtitle">Segmented heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann</p> <p>2010-12-14</p> <p>A segmented heat <span class="hlt">exchanger</span> system for transferring heat energy from an exhaust fluid to a working fluid. The heat <span class="hlt">exchanger</span> system may include a first heat <span class="hlt">exchanger</span> for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat <span class="hlt">exchanger</span> in a parallel flow configuration. In addition, the heat <span class="hlt">exchanger</span> system may include a second heat <span class="hlt">exchanger</span> for receiving working fluid from the first heat <span class="hlt">exchanger</span> and exhaust fluid from a third heat <span class="hlt">exchanger</span>. The working fluid and exhaust fluid may travel through at least a portion of the second heat <span class="hlt">exchanger</span> in a counter flow configuration. Furthermore, the heat <span class="hlt">exchanger</span> system may include a third heat <span class="hlt">exchanger</span> for receiving working fluid from the second heat <span class="hlt">exchanger</span> and exhaust fluid from the first heat <span class="hlt">exchanger</span>. The working fluid and exhaust fluid may travel through at least a portion of the third heat <span class="hlt">exchanger</span> in a parallel flow configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10125599','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10125599"><span id="translatedtitle">Distributions of spontaneous chromosomal aberrations and of spontaneous and <span class="hlt">induced</span> SCE and micronuclei in peripheral lymphocytes from a human population</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bender, M.A.; Setlow, R.B.</p> <p>1992-12-31</p> <p>Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior knowledge of the nature of both spontaneous and <span class="hlt">induced</span> response; if variance is large enough, a given-sized study might be inconclusive, and an adequate study simply too large-to be practical.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6813398','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6813398"><span id="translatedtitle">Distributions of spontaneous chromosomal aberrations and of spontaneous and <span class="hlt">induced</span> SCE and micronuclei in peripheral lymphocytes from a human population</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bender, M.A.; Setlow, R.B.</p> <p>1992-01-01</p> <p>Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior knowledge of the nature of both spontaneous and <span class="hlt">induced</span> response; if variance is large enough, a given-sized study might be inconclusive, and an adequate study simply too large-to be practical.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED428920.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED428920.pdf"><span id="translatedtitle">Educator <span class="hlt">Exchange</span> Resource Guide.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Garza, Cris; Rodriguez, Victor</p> <p></p> <p>This resource guide was developed for teachers and administrators interested in participating in intercultural and international <span class="hlt">exchange</span> programs or starting an <span class="hlt">exchange</span> program. An analysis of an <span class="hlt">exchange</span> program's critical elements discusses <span class="hlt">exchange</span> activities; orientation sessions; duration of <span class="hlt">exchange</span>; criteria for participation; travel,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6515249','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6515249"><span id="translatedtitle">Repair of chromosome damage <span class="hlt">induced</span> by X-irradiation during G/sub 2/ phase in a line of normal human fibroblasts and its malignant derivative</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parshad, R.; Gantt, R.; Sanford, K.K.; Jones, G.M.; Tarone, R.E.</p> <p>1982-08-01</p> <p>A line of normal human skin fibroblasts (KD) differed from its malignant derivative (HUT-14) in the extent of cytogenetic damage <span class="hlt">induced</span> by X-irradiation during G/sub 2/ phase. Malignant cells had significantly more <span class="hlt">chromatid</span> breaks and gaps after exposure to 25, 50, or 100 rad. Results from alkaline elution of cellular DNA immediately after irradiation showed that the normal and malignant cells in asynchronous population were equally sensitive to DNA single-strand breakage by X-irradiation. Caffeine or ..beta..-cytosine arabinoside (ara-C), inhibitors of DNA repair, when added directly following G/sub 2/ phase exposure, significantly increased the incidence of radiation-<span class="hlt">induced</span> <span class="hlt">chromatid</span> damage in the normal cells. In contrast, similar treatment of the malignant cells had little influence. Ara-C differed from caffeine in its effects; whereas both agents increased the frequency of <span class="hlt">chromatid</span> breaks and gaps, only ara-C increased the frequency of gaps to the level observed in the irradiated malignant cells. Addition of catalase, which destroys H/sub 2/O/sub 2/, or mannitol, a scavenger of the derivative free hydroxyl radical (.OH), to the cultures of malignant cells before, during, and following irradiation significantly reduced the <span class="hlt">chromatid</span> damage; and catalase prevented formation of <span class="hlt">chromatid</span> gaps. The DNA damage <span class="hlt">induced</span> by X-ray during G/sub 2/ phase in the normal KD cells was apparently repaired by a caffeine- and ara-C-sensitive mechanism(s) that was deficient or absent in their malignant derivatives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1210146','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1210146"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe<sub>3</sub>O<sub>4</sub> dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; Dai, Sheng</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe<sub>3</sub>O<sub>4</sub> dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe<sub>3</sub>O<sub>4</sub> nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe<sub>3</sub>O<sub>4</sub> nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe<sub>3</sub>O<sub>4</sub> is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe<sub>3</sub>O<sub>4</sub> into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867004','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867004"><span id="translatedtitle">Corrosive resistant heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Richlen, Scott L.</p> <p>1989-01-01</p> <p>A corrosive and errosive resistant heat <span class="hlt">exchanger</span> which recovers heat from a contaminated heat stream. The heat <span class="hlt">exchanger</span> utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat <span class="hlt">exchanger</span> surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat <span class="hlt">exchanger</span> wall. Heat from the heat stream is transferred by radiation to the heat <span class="hlt">exchanger</span> wall. Heat is removed from the outer heat <span class="hlt">exchanger</span> wall by a heat recovery medium.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23215782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23215782"><span id="translatedtitle">Influenza virus subpopulations: <span class="hlt">exchange</span> of lethal H5N1 virus NS for H1N1 virus NS triggers de novo generation of defective-interfering particles and enhances interferon-<span class="hlt">inducing</span> particle efficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ngunjiri, John M; Buchek, Gregory M; Mohni, Kareem N; Sekellick, Margaret J; Marcus, Philip I</p> <p>2013-03-01</p> <p>Reassortment of influenza A viruses is known to affect viability, replication efficiency, antigenicity, host range, and virulence, and can generate pandemic strains. In this study, we demonstrated that the specific <span class="hlt">exchange</span> of the NS gene segment from highly pathogenic A/HK/156/97 (H5N1) [E92 or E92D NS1] virus for the cognate NS gene segment of A/PR/834(H1N1) [D92 NS1] virus did not cause a significant change in the sizes of infectious particle subpopulations. However, it resulted in 2 new phenotypic changes: (1) de novo generation of large subpopulations of defective-interfering particles (DIPs); and (2) enhancement of interferon (IFN)-<span class="hlt">inducing</span> particle efficiency leading to an order of magnitude or higher quantum (peak) yield of IFN in both avian and mammalian cells. These changes were attributed to loss of function of the H5N1-NS gene products. Most notably, the NS <span class="hlt">exchange</span> obliterated the usual IFN-induction-suppressing capacity associated with expression of full-size NS1 proteins, and hence functionally mimicked deletions in the NS1 gene. The loss of NS1-mediated suppression of IFN induction, de novo generation of DIPs, and the concomitant enhancement of IFN-<span class="hlt">inducing</span> particle efficiency suggest that in an attenuated background, the H5N1-NS could be used to formulate a self-adjuvanting live attenuated influenza vaccine similar to viruses with deletions in the NS1 gene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39...47A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39...47A"><span id="translatedtitle">Radiation <span class="hlt">induced</span> genome instability: multiscale modelling and data analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andreev, Sergey; Eidelman, Yuri</p> <p>2012-07-01</p> <p>Genome instability (GI) is thought to be an important step in cancer induction and progression. Radiation <span class="hlt">induced</span> GI is usually defined as genome alterations in the progeny of irradiated cells. The aim of this report is to demonstrate an opportunity for integrative analysis of radiation <span class="hlt">induced</span> GI on the basis of multiscale modelling. Integrative, systems level modelling is necessary to assess different pathways resulting in GI in which a variety of genetic and epigenetic processes are involved. The multilevel modelling includes the Monte Carlo based simulation of several key processes involved in GI: DNA double strand breaks (DSBs) generation in cells initially irradiated as well as in descendants of irradiated cells, damage transmission through mitosis. Taking the cell-cycle-dependent generation of DNA/chromosome breakage into account ensures an advantage in estimating the contribution of different DNA damage response pathways to GI, as to nonhomologous vs homologous recombination repair mechanisms, the role of DSBs at telomeres or interstitial chromosomal sites, etc. The preliminary estimates show that both telomeric and non-telomeric DSB interactions are involved in delayed effects of radiation although differentially for different cell types. The computational experiments provide the data on the wide spectrum of GI endpoints (dicentrics, micronuclei, nonclonal translocations, <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosome fragments) similar to those obtained experimentally for various cell lines under various experimental conditions. The modelling based analysis of experimental data demonstrates that radiation <span class="hlt">induced</span> GI may be viewed as processes of delayed DSB induction/interaction/transmission being a key for quantification of GI. On the other hand, this conclusion is not sufficient to understand GI as a whole because factors of DNA non-damaging origin can also <span class="hlt">induce</span> GI. Additionally, new data on <span class="hlt">induced</span> pluripotent stem cells reveal that GI is acquired in normal mature</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082875','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082875"><span id="translatedtitle">Xanthium strumarium L. Extracts Produce DNA Damage Mediated by Cytotoxicity in In Vitro Assays but Does Not <span class="hlt">Induce</span> Micronucleus in Mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Piloto Ferrer, Janet; Cozzi, Renata; Cornetta, Tommaso; Stano, Pasquale; Fiore, Mario; Degrassi, Francesca; De Salvia, Rosella; Remigio, Antonia; Francisco, Marbelis; Quiñones, Olga; Valdivia, Dayana; González, Maria L.; Pérez, Carlos; Sánchez-Lamar, Angel</p> <p>2014-01-01</p> <p>Xanthium strumarium L. is a member of the Asteraceae commonly used in Cuba, mainly as diuretic. Some toxic properties of this plant have also been reported and, to date, very little is known about its genotoxic properties. The present work aims was to evaluate the potential cytotoxic and genotoxic risk of whole extract from Xanthium strumarium L. whole extract of aerial parts. No positive response was observed in a battery of four Salmonella typhimurium strains, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation (liver microsomal S9 fraction from Wistar rats). In CHO cells, high concentrations (25–100 μg/mL) revealed significant reduction in cell viability. Results from sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosome aberrations, and comet assay showed that X. strumarium extract is genotoxic at the highest concentration used, when clear cytotoxic effects were also observed. On the contrary, no increase in micronuclei frequency in bone marrow cells was observed when the extract was orally administered to mice (100, 500, and 2000 mg/Kg doses). The data presented here constitute the most complete study on the genotoxic potential of X. strumarium L. and show that the extract can <span class="hlt">induce</span> in vitro DNA damage at cytotoxic concentrations. PMID:25025061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25025061','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25025061"><span id="translatedtitle">Xanthium strumarium L. extracts produce DNA damage mediated by cytotoxicity in in vitro assays but does not <span class="hlt">induce</span> micronucleus in mice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Piloto Ferrer, Janet; Cozzi, Renata; Cornetta, Tommaso; Stano, Pasquale; Fiore, Mario; Degrassi, Francesca; De Salvia, Rosella; Remigio, Antonia; Francisco, Marbelis; Quiñones, Olga; Valdivia, Dayana; González, Maria L; Pérez, Carlos; Sánchez-Lamar, Angel</p> <p>2014-01-01</p> <p>Xanthium strumarium L. is a member of the Asteraceae commonly used in Cuba, mainly as diuretic. Some toxic properties of this plant have also been reported and, to date, very little is known about its genotoxic properties. The present work aims was to evaluate the potential cytotoxic and genotoxic risk of whole extract from Xanthium strumarium L. whole extract of aerial parts. No positive response was observed in a battery of four Salmonella typhimurium strains, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation (liver microsomal S9 fraction from Wistar rats). In CHO cells, high concentrations (25-100 μg/mL) revealed significant reduction in cell viability. Results from sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosome aberrations, and comet assay showed that X. strumarium extract is genotoxic at the highest concentration used, when clear cytotoxic effects were also observed. On the contrary, no increase in micronuclei frequency in bone marrow cells was observed when the extract was orally administered to mice (100, 500, and 2000 mg/Kg doses). The data presented here constitute the most complete study on the genotoxic potential of X. strumarium L. and show that the extract can <span class="hlt">induce</span> in vitro DNA damage at cytotoxic concentrations. PMID:25025061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=458397','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=458397"><span id="translatedtitle">Cold-sensitive and caffeine-supersensitive mutants of the Schizosaccharomyces pombe dis genes implicated in sister <span class="hlt">chromatid</span> separation during mitosis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ohkura, H; Adachi, Y; Kinoshita, N; Niwa, O; Toda, T; Yanagida, M</p> <p>1988-01-01</p> <p>We isolated novel classes of Schizosaccharomyces pombe cold-sensitive dis mutants that block mitotic chromosome separation (nine mapped in the dis1 gene and one each in the dis2 and dis3 genes). Defective phenotype at restrictive temperature is similar among the mutants; the chromosomes condense and anomalously move to the cell ends in the absence of their disjoining so that they are unequally distributed at the two cell ends. Synchronous culture analyses indicate that the cells can enter into mitosis at normal timing but become lethal during mitosis. In comparison with the wild-type mitosis, defects are found in the early spindle structure, the mitotic chromosome structure, the poleward chromosome movement by the spindle elongation and the telophase spindle degradation. The dis mutants lose at permissive temperature an artificial minichromosome at higher rates than occur in the wild type. We found that all the dis mutants isolated are supersensitive to caffeine at permissive temperature. Furthermore, the mutant cells in the presence of caffeine produce a phenotype similar to that obtained at restrictive temperature. We suggest that the dis genes are required for the sister <span class="hlt">chromatid</span> separation at the time of mitosis and that caffeine might affect the dis gene expression. We cloned, in addition to the dis2+ and dis3+ genes, multicopy extragenic suppressor sequences which complement dis1 and dis2 mutations. A complex regulatory system may exist for the execution of the dis+ gene functions. Images PMID:3409871</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=321452','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=321452"><span id="translatedtitle">The ctf13-30/CTF13 Genomic Haploinsufficiency Modifier Screen Identifies the Yeast Chromatin Remodeling Complex RSC, Which Is Required for the Establishment of Sister <span class="hlt">Chromatid</span> Cohesion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Baetz, Kristin K.; Krogan, Nevan J.; Emili, Andrew; Greenblatt, Jack; Hieter, Philip</p> <p>2004-01-01</p> <p>The budding yeast centromere-kinetochore complex ensures high-fidelity chromosome segregation in mitosis and meiosis by mediating the attachment and movement of chromosomes along spindle microtubules. To identify new genes and pathways whose function impinges on chromosome transmission, we developed a genomic haploinsufficiency modifier screen and used ctf13-30, encoding a mutant core kinetochore protein, as the reference point. We demonstrate through a series of secondary screens that the genomic modifier screen is a successful method for identifying genes that encode nonessential proteins required for the fidelity of chromosome segregation. One gene isolated in our screen was RSC2, a nonessential subunit of the RSC chromatin remodeling complex. rsc2 mutants have defects in both chromosome segregation and cohesion, but the localization of kinetochore proteins to centromeres is not affected. We determined that, in the absence of RSC2, cohesin could still associate with chromosomes but fails to achieve proper cohesion between sister <span class="hlt">chromatids</span>, indicating that RSC has a role in the establishment of cohesion. In addition, numerous subunits of RSC were affinity purified and a new component of RSC, Rtt102, was identified. Our work indicates that only a subset of the nonessential RSC subunits function in maintaining chromosome transmission fidelity. PMID:14729968</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4589785','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4589785"><span id="translatedtitle">The lethal response to Cdk1 inhibition depends on sister <span class="hlt">chromatid</span> alignment errors generated by KIF4 and isoform 1 of PRC1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Voets, Erik; Marsman, Judith; Demmers, Jeroen; Beijersbergen, Roderick; Wolthuis, Rob</p> <p>2015-01-01</p> <p>Cyclin-dependent kinase 1 (Cdk1) is absolutely essential for cell division. Complete ablation of Cdk1 precludes the entry of G2 phase cells into mitosis, and is early embryonic lethal in mice. Dampening Cdk1 activation, by reducing gene expression or upon treatment with cell-permeable Cdk1 inhibitors, is also detrimental for proliferating cells, but has been associated with defects in mitotic progression, and the formation of aneuploid daughter cells. Here, we used a large-scale RNAi screen to identify the human genes that critically determine the cellular toxicity of Cdk1 inhibition. We show that Cdk1 inhibition leads to fatal sister <span class="hlt">chromatid</span> alignment errors and mitotic arrest in the spindle checkpoint. These problems start early in mitosis and are alleviated by depletion of isoform 1 of PRC1 (PRC1-1), by gene ablation of its binding partner KIF4, or by abrogation of KIF4 motor activity. Our results show that, normally, Cdk1 activity must rise above the level required for mitotic entry. This prevents KIF4-dependent PRC1-1 translocation to astral microtubule tips and safeguards proper chromosome congression. We conclude that cell death in response to Cdk1 inhibitors directly relates to chromosome alignment defects generated by insufficient repression of PRC1-1 and KIF4 during prometaphase. PMID:26423135</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26423135','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26423135"><span id="translatedtitle">The lethal response to Cdk1 inhibition depends on sister <span class="hlt">chromatid</span> alignment errors generated by KIF4 and isoform 1 of PRC1.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Voets, Erik; Marsman, Judith; Demmers, Jeroen; Beijersbergen, Roderick; Wolthuis, Rob</p> <p>2015-01-01</p> <p>Cyclin-dependent kinase 1 (Cdk1) is absolutely essential for cell division. Complete ablation of Cdk1 precludes the entry of G2 phase cells into mitosis, and is early embryonic lethal in mice. Dampening Cdk1 activation, by reducing gene expression or upon treatment with cell-permeable Cdk1 inhibitors, is also detrimental for proliferating cells, but has been associated with defects in mitotic progression, and the formation of aneuploid daughter cells. Here, we used a large-scale RNAi screen to identify the human genes that critically determine the cellular toxicity of Cdk1 inhibition. We show that Cdk1 inhibition leads to fatal sister <span class="hlt">chromatid</span> alignment errors and mitotic arrest in the spindle checkpoint. These problems start early in mitosis and are alleviated by depletion of isoform 1 of PRC1 (PRC1-1), by gene ablation of its binding partner KIF4, or by abrogation of KIF4 motor activity. Our results show that, normally, Cdk1 activity must rise above the level required for mitotic entry. This prevents KIF4-dependent PRC1-1 translocation to astral microtubule tips and safeguards proper chromosome congression. We conclude that cell death in response to Cdk1 inhibitors directly relates to chromosome alignment defects generated by insufficient repression of PRC1-1 and KIF4 during prometaphase. PMID:26423135</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2064017','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2064017"><span id="translatedtitle">RAD51C deficiency in mice results in early prophase I arrest in males and sister <span class="hlt">chromatid</span> separation at metaphase II in females</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kuznetsov, Sergey; Pellegrini, Manuela; Shuda, Kristy; Fernandez-Capetillo, Oscar; Liu, Yilun; Martin, Betty K.; Burkett, Sandra; Southon, Eileen; Pati, Debananda; Tessarollo, Lino; West, Stephen C.; Donovan, Peter J.; Nussenzweig, Andre; Sharan, Shyam K.</p> <p>2007-01-01</p> <p>RAD51C is a member of the RecA/RAD51 protein family, which is known to play an important role in DNA repair by homologous recombination. In mice, it is essential for viability. Therefore, we have generated a hypomorphic allele of Rad51c in addition to a null allele. A subset of mice expressing the hypomorphic allele is infertile. This infertility is caused by sexually dimorphic defects in meiotic recombination, revealing its two distinct functions. Spermatocytes undergo a developmental arrest during the early stages of meiotic prophase I, providing evidence for the role of RAD51C in early stages of RAD51-mediated recombination. In contrast, oocytes can progress normally to metaphase I after superovulation but display precocious separation of sister <span class="hlt">chromatids</span>, aneuploidy, and broken chromosomes at metaphase II. These defects suggest a possible late role of RAD51C in meiotic recombination. Based on the marked reduction in Holliday junction (HJ) resolution activity in Rad51c-null mouse embryonic fibroblasts, we propose that this late function may be associated with HJ resolution. PMID:17312021</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22255208','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22255208"><span id="translatedtitle">Hydrogen bonding <span class="hlt">induced</span> proton <span class="hlt">exchange</span> reactions in dense D{sub 2}-NH{sub 3} and D{sub 2}-CH{sub 4} mixtures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Borstad, Gustav M.; Yoo, Choong-Shik</p> <p>2014-01-28</p> <p>We have investigated high-pressure behaviors of simple binary mixtures of NH{sub 3} and D{sub 2} to 50 GPa and CH{sub 4} and D{sub 2} to 30 GPa using confocal micro-Raman spectroscopy. The spectral data indicate strong proton <span class="hlt">exchange</span> reactions occur in dense D{sub 2}-NH{sub 3} mixture, producing different isotopes of ammonia such as NH{sub 3}, NH{sub 2}D, NHD{sub 2}, and ND{sub 3}. In contrast, the proton <span class="hlt">exchange</span> process in dense D{sub 2}-CH{sub 4} mixture is highly limited, and no vibration feature is apparent for deuterated methane. The vibrational modes of H{sub 2} isotopes in D{sub 2}-NH{sub 3} are blue shifted from those of pure H{sub 2} isotopes, whereas the modes of D{sub 2}-CH{sub 4} show overall agreement with those in pure D{sub 2} and CH{sub 4}. In turn, this result advocates the presence of strong repulsion and thereby internal pressure in D{sub 2}-NH{sub 3} mixture, which are absent in D{sub 2}-CH{sub 4}. In fact, the bond length of hydrogen molecules in D{sub 2}-NH{sub 3}, calculated from the present spectral data, is shorter than that observed in pure hydrogen – supporting the enhanced intermolecular interaction in the mixture. Comparing the present spectral results with those previously observed in D{sub 2}-H{sub 2}O mixtures further suggests that the strength of repulsive interaction or the magnitude of internal pressure in the mixtures is proportional to the strength of hydrogen bonding in H{sub 2}O, NH{sub 3}, and CH{sub 4} in decreasing order. Hence, we suggest that the proton <span class="hlt">exchange</span> is assisted by hydrogen bonding in these molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvB..84u4435F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvB..84u4435F"><span id="translatedtitle">Spin reorientation in α-Fe2O3 nanoparticles <span class="hlt">induced</span> by interparticle <span class="hlt">exchange</span> interactions in α-Fe2O3/NiO nanocomposites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frandsen, C.; Lefmann, K.; Lebech, B.; Bahl, C. R. H.; Brok, E.; Ancoña, S. N.; Theil Kuhn, L.; Keller, L.; Kasama, T.; Gontard, L. C.; Mørup, S.</p> <p>2011-12-01</p> <p>We report that the spin structure of α-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to ˜70∘) in α-Fe2O3 nanoparticles has, in appearance, similarities to the Morin transition in bulk α-Fe2O3, but its origin is different—it is caused by <span class="hlt">exchange</span> coupling between aggregated nanoparticles of α-Fe2O3 and NiO with different directions of easy axes of magnetization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/875197','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/875197"><span id="translatedtitle">Woven heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Piscitella, Roger R.</p> <p>1987-01-01</p> <p>In a woven ceramic heat <span class="hlt">exchanger</span> using the basic tube-in-shell design, each heat <span class="hlt">exchanger</span> consisting of tube sheets and tube, is woven separately. Individual heat <span class="hlt">exchangers</span> are assembled in cross-flow configuration. Each heat <span class="hlt">exchanger</span> is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1176569','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176569"><span id="translatedtitle">Woven heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Piscitella, Roger R.</p> <p>1987-05-05</p> <p>In a woven ceramic heat <span class="hlt">exchanger</span> using the basic tube-in-shell design, each heat <span class="hlt">exchanger</span> consisting of tube sheets and tube, is woven separately. Individual heat <span class="hlt">exchangers</span> are assembled in cross-flow configuration. Each heat <span class="hlt">exchanger</span> is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20982520','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20982520"><span id="translatedtitle">Water-molecule fragmentation <span class="hlt">induced</span> by charge <span class="hlt">exchange</span> in slow collisions with He{sup +} and He{sup 2+} ions in the keV-energy region</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cabrera-Trujillo, R.; Deumens, E.; Oehrn, Y.; Quinet, O.; Sabin, J. R.; Stolterfoht, N.</p> <p>2007-05-15</p> <p>Charge <span class="hlt">exchange</span> and fragmentation in the collision systems He{sup 2+}+H{sub 2}O and He{sup +}+H{sub 2}O are theoretically investigated at projectile energies of a few keV. The calculations are based on the electron nuclear dynamics (END) method which solves the time-dependent Schroedinger equation. Total and differential cross sections for charge <span class="hlt">exchange</span> are evaluated by averaging over 10 orientations of the H{sub 2}O molecule. Summed total electron capture cross sections are found to be in good agreement with available experimental data. Projectile scattering was studied in the full angular range with respect to the incident beam direction. The theory provides a description of the fragmentation mechanisms such as Coulomb explosion and binary collision processes. For impact parameters below 3.5 a.u., we find that single and double electron capture occurs, resulting always in full fragmentation of H{sub 2}O independent of the target orientation for {sup 3}He{sup 2+} ions. Hydrogen and oxygen fragments and its respective ions, are studied as a function of emission angle and energy. In the binary collisions regime the theoretical results are found to be in excellent agreement with previous experimental data. In the Coulomb explosion regime the theoretical data are found to peak at specific angles including 90 degree sign , which is consistent with the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhRvA..75e2702C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhRvA..75e2702C"><span id="translatedtitle">Water-molecule fragmentation <span class="hlt">induced</span> by charge <span class="hlt">exchange</span> in slow collisions with He+ and He2+ ions in the keV-energy region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cabrera-Trujillo, R.; Deumens, E.; Öhrn, Y.; Quinet, O.; Sabin, J. R.; Stolterfoht, N.</p> <p>2007-05-01</p> <p>Charge <span class="hlt">exchange</span> and fragmentation in the collision systems He2++H2O and He++H2O are theoretically investigated at projectile energies of a few keV. The calculations are based on the electron nuclear dynamics (END) method which solves the time-dependent Schrödinger equation. Total and differential cross sections for charge <span class="hlt">exchange</span> are evaluated by averaging over 10 orientations of the H2O molecule. Summed total electron capture cross sections are found to be in good agreement with available experimental data. Projectile scattering was studied in the full angular range with respect to the incident beam direction. The theory provides a description of the fragmentation mechanisms such as Coulomb explosion and binary collision processes. For impact parameters below 3.5a.u. , we find that single and double electron capture occurs, resulting always in full fragmentation of H2O independent of the target orientation for He2+3 ions. Hydrogen and oxygen fragments and its respective ions, are studied as a function of emission angle and energy. In the binary collisions regime the theoretical results are found to be in excellent agreement with previous experimental data. In the Coulomb explosion regime the theoretical data are found to peak at specific angles including 90°, which is consistent with the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5627731','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5627731"><span id="translatedtitle">Woven heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Piscitella, R.R.</p> <p>1984-07-16</p> <p>This invention relates to a heat <span class="hlt">exchanger</span> for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat <span class="hlt">exchanger</span> using the basic tube-in-shell design, each heat <span class="hlt">exchanger</span> consisting of tube sheets and tube, is woven separately. Individual heat <span class="hlt">exchangers</span> are assembled in cross-flow configuration. Each heat <span class="hlt">exchanger</span> is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16278101','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16278101"><span id="translatedtitle">Correlation between pulmonary gas <span class="hlt">exchange</span> and basal and nitroglycerin (GTN)-<span class="hlt">induced</span> exhaled nitric oxide (eNO) in patients undergoing cardiac surgery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kövesi, Tamás; Szabo, Anita; Royston, David; Marczin, Nándor</p> <p>2005-12-01</p> <p>The relationship between eNO and events in the alveolar-capillary unit in acute lung injury remains to be established. Since endogenous eNO largely originates from the airway epithelium, but nitroglycerin (GTN)-<span class="hlt">induced</span> eNO is due to microvascular/alveolar metabolism, we have proposed to use basal and GTN-<span class="hlt">induced</span> eNO as metabolic markers of the airway--and microvascular/alveolar function, respectively. The current work investigates the relationship between basal and GTN-<span class="hlt">induced</span> eNO and oxygenation parameters (PaO(2)/FiO(2) ratio) in patients undergoing cardiac surgery utilising cardiopulmonary bypass (CPB). Breath by breath eNO measurements were made in 10 patients before, and 1 and 3 h after CPB either under basal conditions or following intravenous administration of GTN (1, 2 and 3 microg/kg). Basal eNO remained unchanged, whereas GTN-<span class="hlt">induced</span> eNO was reduced following CPB. Also, there was a transient reduction in PaO(2)/FiO(2) ratio 1 h after CPB (32+/-4 vs. 44+/-3 kPa). A negative correlation was found between oxygenation and basal eNO by Pearson's correlation test and linear regression analysis suggesting that decreased oxygenation was associated with increased basal eNO. In contrast, a decrease in GTN-<span class="hlt">induced</span> eNO positively correlated with reduced oxygenation index (R=0.533, p=0.002). These data suggest that differential relationships exist between basal and nitrovasodilator-<span class="hlt">induced</span> eNO and oxygenation indices during subclinical lung injury in patients following CPB and that GTN-<span class="hlt">induced</span> eNO evolution may reflect better microvascular events and injury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731"><span id="translatedtitle">Oxygen desaturation during a 6-minute walk test as a predictor of maximal exercise-<span class="hlt">induced</span> gas <span class="hlt">exchange</span> abnormalities in sarcoidosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chenivesse, Cecile; Boulanger, Sarah; Langlois, Carole; Wemeau-Stervinou, Lidwine; Perez, Thierry</p> <p>2016-01-01</p> <p>Background Common tests for evaluating gas <span class="hlt">exchange</span> impairment have different strengths and weaknesses. Alveolar-to-arterial oxygen pressure difference (AaDO2) at peak exercise is a sensitive indicator but it cannot be measured repeatedly. Diffusing capacity of the lung for carbon monoxide (DLco) is measured at rest and may be too insensitive to predict the effects of exercise on gas <span class="hlt">exchange</span> impairment. Oxygen desaturation during a 6-minute walk test (∆SpO2-6MWT) can be measured repeatedly, but its value in sarcoidosis is unknown. Here, we evaluated the ability of ∆SpO2-6MWT and DLco to predict gas <span class="hlt">exchange</span> impairment during exercise in sarcoidosis. Methods This retrospective study of 130 subjects with sarcoidosis investigated the relationship between DLco, ∆SpO2-6MWT, and peak AaDO2 using correlation tests, inter-test reliability analyses, and predictive values. For the analyses of inter-test reliability and predictive values, DLco, peak AaDO2, and ∆SpO2-6MWT were considered as binary variables (normal/abnormal) according to previously defined thresholds. Results Correlation coefficients between DLco, ∆SpO2-6MWT, and peak AaDO2 were intermediate (0.53–0.67, P<0.0003) and Kappa coefficients were low (0.21–0.42, P=0.0003–0.02). DLco predicted (I) increased peak AaDO2 with a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 78% and (II) increased ∆SpO2-6MWT with a PPV at 36% and an NPV at 88%. Normal DLco was a good predictor of the absence of severe desaturation during the 6MWT (94% NPV) and at peak exercise during cardiopulmonary exercise test (CPET) (100% NPV). ∆SpO2-6MWT predicted peak AaDO2 increase with a PPV of 74% and an NPV of 60%. Conclusions In a large population of sarcoidosis patients, neither ∆SpO2-6MWT nor DLco was a good predictor of increased peak AaDO2. In contrast, normal DLco was a good predictor of the absence of severe desaturation during the 6MWT and at peak exercise during CPET.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731"><span id="translatedtitle">Oxygen desaturation during a 6-minute walk test as a predictor of maximal exercise-<span class="hlt">induced</span> gas <span class="hlt">exchange</span> abnormalities in sarcoidosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chenivesse, Cecile; Boulanger, Sarah; Langlois, Carole; Wemeau-Stervinou, Lidwine; Perez, Thierry</p> <p>2016-01-01</p> <p>Background Common tests for evaluating gas <span class="hlt">exchange</span> impairment have different strengths and weaknesses. Alveolar-to-arterial oxygen pressure difference (AaDO2) at peak exercise is a sensitive indicator but it cannot be measured repeatedly. Diffusing capacity of the lung for carbon monoxide (DLco) is measured at rest and may be too insensitive to predict the effects of exercise on gas <span class="hlt">exchange</span> impairment. Oxygen desaturation during a 6-minute walk test (∆SpO2-6MWT) can be measured repeatedly, but its value in sarcoidosis is unknown. Here, we evaluated the ability of ∆SpO2-6MWT and DLco to predict gas <span class="hlt">exchange</span> impairment during exercise in sarcoidosis. Methods This retrospective study of 130 subjects with sarcoidosis investigated the relationship between DLco, ∆SpO2-6MWT, and peak AaDO2 using correlation tests, inter-test reliability analyses, and predictive values. For the analyses of inter-test reliability and predictive values, DLco, peak AaDO2, and ∆SpO2-6MWT were considered as binary variables (normal/abnormal) according to previously defined thresholds. Results Correlation coefficients between DLco, ∆SpO2-6MWT, and peak AaDO2 were intermediate (0.53–0.67, P<0.0003) and Kappa coefficients were low (0.21–0.42, P=0.0003–0.02). DLco predicted (I) increased peak AaDO2 with a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 78% and (II) increased ∆SpO2-6MWT with a PPV at 36% and an NPV at 88%. Normal DLco was a good predictor of the absence of severe desaturation during the 6MWT (94% NPV) and at peak exercise during cardiopulmonary exercise test (CPET) (100% NPV). ∆SpO2-6MWT predicted peak AaDO2 increase with a PPV of 74% and an NPV of 60%. Conclusions In a large population of sarcoidosis patients, neither ∆SpO2-6MWT nor DLco was a good predictor of increased peak AaDO2. In contrast, normal DLco was a good predictor of the absence of severe desaturation during the 6MWT and at peak exercise during CPET. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20823050','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20823050"><span id="translatedtitle">The efficiacy of bismuth subnitrate against genotoxicity and oxidative stress <span class="hlt">induced</span> by aluminum sulphate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turkez, Hasan; Geyikoglu, Fatime</p> <p>2011-03-01</p> <p>Aluminum (Al) is commonly used in industrial processes and drugs and is thought to <span class="hlt">induce</span> erythrocytes damage via activation of oxidative stress. Recently, bismuth (Bi)-containing drugs are used in the treatment of various diseases. However, uncertain effects of Bi in blood tissue may participate in the therapeutic efficacy of Bi compounds as related to metals. Hence, this study aimed to determine the roles on human blood cells of the various concentrations of aluminum sulphate (Al(2)(SO(4))(3)) and bismuth subnitrate (BSN), separate and together. With this aim, oxidative status was assessed on erythrocytes by measuring following oxidative stress markers: reduced glutathione (GSH), superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G-6-PDH) and catalase (CAT). Two chemicals were tested for their ability to <span class="hlt">induce</span> cytogenetic change in human lymphocytes using assays for chromosome aberrations (CAs) and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs). Our results showed that high dose of Al(2)(SO(4))(3) (20 µg/mL) caused oxidative stress and increased CA and SCE frequencies. Whereas, BSN doses did not change CA and SCE rates. Moreover, it led to changes of antioxidant capacity at different concentrations. After concomitant treatment with Al(2)(SO(4))(3) and BSN, the effects of BSN doses were different on enzyme activities and decreased the genotoxic damage. However, the high dose of BSN and Al(2)(SO(4))(3) was shown to enhance the frequencies of CAs and SCEs in a synergistic manner. In conclusion, BSN could be effective in the protection against the blood toxicity of Al(2)(SO(4))(3).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27193269','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27193269"><span id="translatedtitle">1,2:3,4-Diepoxybutane <span class="hlt">Induces</span> Multipolar Mitosis in Cultured Human Lymphocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barajas Torres, Reyna Lucía; Domínguez Cruz, Martín Daniel; Borjas Gutiérrez, César; Ramírez Dueñas, María de Lourdes; Magaña Torres, María Teresa; González García, Juan Ramón</p> <p>2016-01-01</p> <p>1,3-Butadiene, a colorless gas regularly used in the production of plastics, thermoplastic resins, and styrene-butadiene rubber, poses an increased leukemia mortality risk to workers in this field. 1,3-Butadiene is also produced by incomplete combustion of motor fuels or by tobacco smoking. It is absorbed principally through the respiratory system and metabolized by several enzymes rendering 1,2:3,4-diepoxybutane (DEB), which has the highest genotoxic potency of all metabolites of 1,3-butadiene. DEB is considered a carcinogen mainly due to its high potential as clastogen, which <span class="hlt">induces</span> structural chromosome aberrations such as sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosomal breaks, and micronuclei. Due to its clastogenic effect, DEB is one of the most used agents for diagnostic studies of Fanconi anemia, a recessively inherited disease related to mutations affecting several genes involved in a common DNA repair pathway. When performing Fanconi anemia diagnostic tests in our laboratory, we have observed occasional multipolar mitosis (MM) in lymphocyte cultures exposed to 0.1 μg/ml of DEB and harvested in the absence of any mitotic spindle inhibitor. Although previous studies reported an aneugenic effect (i.e. it <span class="hlt">induces</span> aneuploidy) of DEB, no mechanism was suggested to explain such observations. Therefore, the aim of this study was to investigate whether exposure to 0.1 μg/ml of DEB is significantly associated with the occurrence of MM. We blindly assessed the frequency of MM in lymphocyte cultures from 10 nonsmoking healthy individuals. Two series of 3 cultures were performed from each sample under different conditions: A, without DEB; B, with 0.1 μg/ml of DEB, and C, with 25 μM of mitomycin C as positive control. Cultures exposed to DEB showed higher frequencies of MM (23 of 2,000 cells) than did the unexposed ones (3 of 2,000 cells). PMID:27193269</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3398457','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3398457"><span id="translatedtitle">Root and shoot gas <span class="hlt">exchange</span> respond additively to moderate ozone and methyl jasmonate without induction of ethylene: ethylene is <span class="hlt">induced</span> at higher O3 concentrations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grantz, D.A.; Vu, H.-B.</p> <p>2012-01-01</p> <p>The available literature is conflicting on the potential protection of plants against ozone (O3) injury by exogenous jasmonates, including methyl jasmonate (MeJA). Protective antagonistic interactions of O3 and MeJA have been observed in some systems and purely additive effects in others. Here it is shown that chronic exposure to low to moderate O3 concentrations (4–114 ppb; 12 h mean) and to MeJA <span class="hlt">induced</span> additive reductions in carbon assimilation (A n) and root respiration (R r), and in calculated whole plant carbon balance. Neither this chronic O3 regime nor MeJA <span class="hlt">induced</span> emission of ethylene (ET) from the youngest fully expanded leaves. ET emission was <span class="hlt">induced</span> by acute 3 h pulse exposure to much higher O3 concentrations (685 ppb). ET emission was further enhanced in plants treated with MeJA. Responses of growth, allocation, photosynthesis, and respiration to moderate O3 concentrations and to MeJA appear to be independent and additive, and not associated with emission of ET. These results suggest that responses of Pima cotton to environmentally relevant O3 are not mediated by signalling pathways associated with ET and MeJA, though these pathways are <span class="hlt">inducible</span> in this species and exhibit a synergistic O3×MeJA interaction at very high O3 concentrations. PMID:22563119</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=260309','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=260309"><span id="translatedtitle">Minimal influence of G-protein null mutations on ozone-<span class="hlt">induced</span> changes in gene expression, foliar injury, gas-<span class="hlt">exchange</span> and peroxidase activity in Arabidopsis thaliana L</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Ozone uptake by plants leads to an increase in reactive oxygen species (ROS) in the intercellular space of leaves and <span class="hlt">induces</span> signalling processes reported to involve the membrane-bound heterotrimeric G-protein complex. Therefore, potential G-protein-mediated response mechanisms to ozone were compar...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11208126','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11208126"><span id="translatedtitle">The tail domain of myosin M catalyses nucleotide <span class="hlt">exchange</span> on Rac1 GTPases and can <span class="hlt">induce</span> actin-driven surface protrusions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Geissler, H; Ullmann, R; Soldati, T</p> <p>2000-05-01</p> <p>Members of the myosin superfamily play crucial roles in cellular processes including management of the cortical cytoskeleton, organelle transport and signal transduction. GTPases of the Rho family act as key control elements in the reorganization of the actin cytoskeleton in response to growth factors, and other functions such as membrane trafficking, transcriptional regulation, growth control and development. Here, we describe a novel unconventional myosin from Dictyostelium discoideum, MyoM. Primary sequence analysis revealed that it has the appearance of a natural chimera between a myosin motor domain and a guanine nucleotide <span class="hlt">exchange</span> factor (GEF) domain for Rho GTPases. The functionality of both domains was established. Binding of the motor domain to F-actin was ATP-dependent and potentially regulated by phosphorylation. The GEF domain displayed selective activity on Rac1-related GTPases. Overexpression, rather than absence of MyoM, affected the cell morphology and viability. Particularly in response to hypo-osmotic stress, cells overexpressing the MyoM tail domain extended massive actin-driven protrusions. The GEF was enriched at the tip of growing protuberances, probably through its pleckstrin homology domain. MyoM is the first unconventional myosin containing an active Rac-GEF domain, suggesting a role at the interface of Rac-mediated signal transduction and remodeling of the actin cytoskeleton. PMID:11208126</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27589572','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27589572"><span id="translatedtitle">Anion-<span class="hlt">Exchange</span> <span class="hlt">Induced</span> Strong π-π Interactions in Single Crystalline Naphthalene Diimide for Nitroexplosive Sensing: An Electronic Prototype for Visual on-Site Detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalita, Anamika; Hussain, Sameer; Malik, Akhtar Hussain; Barman, Ujjwol; Goswami, Namami; Iyer, Parameswar Krishnan</p> <p>2016-09-28</p> <p>A new derivative of naphthalene diimide (NDMI) was synthesized that displayed optical, electrical, and visual changes exclusively for the most widespread nitroexplosive and highly water-soluble toxicant picric acid (PA) due to strong π-π interactions, dipole-charge interaction, and a favorable ground state electron transfer process facilitated by Coulombic attraction. The sensing mechanism and interaction between NDMI with PA is demonstrated via X-ray diffraction analysis, (1)H NMR studies, cyclic voltammetry, UV-visible/fluorescence spectroscopy, and lifetime measurements. Single crystal X-ray structure of NDMI revealed the formation of self-assembled crystalline network assisted by noncovalent C-H···I interactions that get disrupted upon introducing PA as a result of anion <span class="hlt">exchange</span> and strong π-π stacking between NDMI and PA. Morphological studies of NDMI displayed large numbers of single crystalline microrods along with some three-dimensional (3D) daisy-like structures which were fabricated on Al-coated glass substrate to construct a low-cost two terminal sensor device for realizing vapor mode detection of PA at room temperature and under ambient conditions. Furthermore, an economical and portable electronic prototype was developed for visual and on-site detection of PA vapors under exceptionally realistic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6592261','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6592261"><span id="translatedtitle">Solvent effects on the synthesis of ion-<span class="hlt">exchange</span> membranes by radiation-<span class="hlt">induced</span> graft polymerization of methyl. cap alpha. ,. beta. ,. beta. -trifluoroacrylate. [Freon 113</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Omichi, H.; Okamoto, J.</p> <p>1982-06-01</p> <p>Methyl ..cap alpha..,..beta..,..beta..-trifluoroacrylate (MTFA) was grafted onto polyethylene (PE) film and fluorine-containing films to make ion-<span class="hlt">exchange</span> membranes. In the case of PE the grafting yield was not influenced by the presence of trifluorotrichloroethane (Freon 113) in the reaction mixture, while the presence of methanol decreased the grafting yield. The transversal distribution of graft chains in the film observed by electron-probe x-ray microanalysis showed that when the grafting was carried out in the presence of Freon the amount of graft chains in the central part of PE film was much larger than that at the film surface and that the grafts obtained in the absence of Freon were located mainly at the film surface. The electric resistance of the graft PE film obtained in the presence of Freon decreased more than that of the one obtained in the absence of Freon. The weight loss of the graft films in H/sub 2/O/sub 2/ solution was negligibly small.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846941','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846941"><span id="translatedtitle">Pendrin, an anion <span class="hlt">exchanger</span> on lung epithelial cells, could be a novel target for lipopolysaccharide-<span class="hlt">induced</span> acute lung injury mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jia, Chun-E; Jiang, Dingyuan; Dai, Huaping; Xiao, Fei; Wang, Chen</p> <p>2016-01-01</p> <p>Objective: The aim of this study is to evaluate the role of pendrin in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and to explore whether pendrin expression existing on alveolar cells. Methods: ALI C57BL/6 mice model <span class="hlt">induced</span> by lipopolysaccharide (LPS) was established. The expression of pendrin in lung was analyzed by RT-PCR and western blotting methods, the changes of lung inflammatory parameters and pathology were observed, the cellular distribution of pendrin in the lung was determined using immunofluorescence. Statistical comparisons between groups were made by two-tailed Student’s t-test. Results: Enhanced expression of the slc26a4 gene and production of pendrin in lungs of LPS-<span class="hlt">induced</span> ALI mice were confirmed. In comparison with vehicle-control mice, methazolamide treatment mitigated lung inflammatory parameters and pathology. IL-6 and MCP-1 in lung tissues and BALF in methazolamide-treated mice were statistically decreased. Methazolamide treatment had significant effect on the total protein concentration in the BALF and the ratio of lung wet/dry weight. The percentage of macrophages in the BALF was increased. There was a low expression of pendrin in ATII. Conclusions: Pendrin may be involved in pathological process of LPS-<span class="hlt">induced</span> ALI. Inhibition of the pendrin function could be used to treat ALI. Airway epithelial cell may be a valuable therapeutic target for discovering and developing new drugs and/or new therapeutic strategies for the treatment of ALI/ARDS. PMID:27158384</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://epi.grants.cancer.gov/pharm/pharmacoepi_db/indiana.html','NCI'); return false;" href="https://epi.grants.cancer.gov/pharm/pharmacoepi_db/indiana.html"><span id="translatedtitle">Indiana Health Information <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p>The Indiana Health Information <span class="hlt">Exchange</span> is comprised of various Indiana health care institutions, established to help improve patient safety and is recognized as a best practice for health information <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863101','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863101"><span id="translatedtitle">Charge <span class="hlt">exchange</span> system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Anderson, Oscar A.</p> <p>1978-01-01</p> <p>An improved charge <span class="hlt">exchange</span> system for substantially reducing pumping requirements of excess gas in a controlled thermonuclear reactor high energy neutral beam injector. The charge <span class="hlt">exchange</span> system utilizes a jet-type blanket which acts simultaneously as the charge <span class="hlt">exchange</span> medium and as a shield for reflecting excess gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871701','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871701"><span id="translatedtitle">Release of GTP <span class="hlt">Exchange</span> Factor Mediated Down-Regulation of Abscisic Acid Signal Transduction through ABA-<span class="hlt">Induced</span> Rapid Degradation of RopGEFs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Waadt, Rainer; Schroeder, Julian I.</p> <p>2016-01-01</p> <p>The phytohormone abscisic acid (ABA) is critical to plant development and stress responses. Abiotic stress triggers an ABA signal transduction cascade, which is comprised of the core components PYL/RCAR ABA receptors, PP2C-type protein phosphatases, and protein kinases. Small GTPases of the ROP/RAC family act as negative regulators of ABA signal transduction. However, the mechanisms by which ABA controls the behavior of ROP/RACs have remained unclear. Here, we show that an Arabidopsis guanine nucleotide <span class="hlt">exchange</span> factor protein RopGEF1 is rapidly sequestered to intracellular particles in response to ABA. GFP-RopGEF1 is sequestered via the endosome-prevacuolar compartment pathway and is degraded. RopGEF1 directly interacts with several clade A PP2C protein phosphatases, including ABI1. Interestingly, RopGEF1 undergoes constitutive degradation in pp2c quadruple abi1/abi2/hab1/pp2ca mutant plants, revealing that active PP2C protein phosphatases protect and stabilize RopGEF1 from ABA-mediated degradation. Interestingly, ABA-mediated degradation of RopGEF1 also plays an important role in ABA-mediated inhibition of lateral root growth. The presented findings point to a PP2C-RopGEF-ROP/RAC control loop model that is proposed to aid in shutting off ABA signal transduction, to counteract leaky ABA signal transduction caused by “monomeric” PYL/RCAR ABA receptors in the absence of stress, and facilitate signaling in response to ABA. PMID:27192441</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1565561','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1565561"><span id="translatedtitle">Effect of increased cardiac output on liver blood flow, oxygen <span class="hlt">exchange</span> and metabolic rate during longterm endotoxin-<span class="hlt">induced</span> shock in pigs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Šantak, Borislav; Radermacher, Peter; Adler, Jens; Iber, Thomas; Rieger, Karen M; Wachter, Ulrich; Vogt, Josef; Georgieff, Michael; Träger, Karl</p> <p>1998-01-01</p> <p>We investigated hepatic blood flow, O2 <span class="hlt">exchange</span> and metabolism in porcine endotoxic shock (Control, n=8; Endotoxin, n=10) with administration of hydroxyethylstarch to maintain arterial pressure (MAP)>60 mmHg. Before and 12, 18 and 24 h after starting continuous i.v. endotoxin we measured portal venous and hepatic arterial blood flow, intracapillary haemoglobin O2 saturation (Hb-O2%) of the liver surface and arterial, portal and hepatic venous lactate, pyruvate, glyercol and alanine concentrations. Glucose production rate was derived from the plasma isotope enrichment during infusion of [6,6-2H2]-glucose. Despite a sustained 50% increase in cardiac output endotoxin caused a progressive, significant fall in MAP. Liver blood flow significantly increased, but endotoxin affected neither hepatic O2 delivery and uptake nor mean intracapillary Hb-O2% and Hb-O2% frequency distributions. Endotoxin nearly doubled endogenous glucose production rate while hepatic lactate, alanine and glycerol uptake rates progressively decreased significantly. The lactate uptake rate even became negative (P<0.05 vs Control). Endotoxin caused portal and hepatic venous pH to fall significantly concomitant with significantly increased arterial, portal and hepatic venous lactate/pyruvate ratios. During endotoxic shock increased cardiac output achieved by colloid infusion maintained elevated liver blood flow and thereby macro- and microcirculatory O2 supply. Glucose production rate nearly doubled with complete dissociation of hepatic uptake of glucogenic precursors and glucose release. Despite well-preserved capillary oxygenation increased lactate/pyruvate ratios reflecting impaired cytosolic redox state suggested deranged liver energy balance, possibly due to the O2 requirements of gluconeogenesis. PMID:9756385</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3557307','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3557307"><span id="translatedtitle">Excitation-<span class="hlt">induced</span> <span class="hlt">exchange</span> of Na+, K+, and Cl− in rat EDL muscle in vitro and in vivo: Physiology and pathophysiology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>In skeletal muscle, excitation leads to increased [Na+]i, loss of K+, increased [K+]o, depolarization, and Cl− influx. This study quantifies these changes in rat extensor digitorum longus (EDL) muscles in vitro and in vivo using flame photometric determination of Na+ and K+ and 36Cl as a tracer for Cl−. In vitro, 5-Hz stimulation for 300 s increased intracellular Na+ content by 4.6 ± 1.2 µmol/g wet wt (P < 0.002) and decreased intracellular K+ content by 5.5 ± 2.3 µmol/g wet wt (P < 0.03). This would increase [K+]o by 28 ± 12 mM, sufficient to cause severe loss of excitability as the result of inactivation of Na+ channels. In rat EDL, in vivo stimulation at 5 Hz for 300 s or 60 Hz for 60 s <span class="hlt">induced</span> significant loss of K+ (P < 0.01), sufficient to increase [K+]o by 71 ± 22 mM and 73 ± 15 mM, respectively. In spite of this, excitability may be maintained by the rapid and marked stimulation of the electrogenic Na+,K+ pumps already documented. This may require full utilization of the transport capacity of Na+,K+ pumps, which then becomes a limiting factor for physical performance. In buffer containing 36Cl, depolarization <span class="hlt">induced</span> by increasing [K+]o to 40–80 mM augmented intracellular 36Cl by 120–399% (P < 0.001). Stimulation for 120–300 s at 5–20 Hz increased intracellular 36Cl by 100–188% (P < 0.001). In rats, Cl− transport in vivo was examined by injecting 36Cl, where electrical stimulation at 5 Hz for 300 s or 60 Hz for 60 s increased 36Cl uptake by 81% (P < 0.001) and 84% (P < 0.001), respectively, indicating excitation-<span class="hlt">induced</span> depolarization. Cl− influx favors repolarization, improving K+ clearance and maintenance of excitability. In conclusion, excitation-<span class="hlt">induced</span> fluxes of Na+, K+, and Cl− can be quantified in vivo, providing new evidence that in working muscles, extracellular accumulation of K+ is considerably higher than previously observed and the resulting depression of membrane excitability may be a major cause of muscle fatigue</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11481484','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11481484"><span id="translatedtitle">Growth inhibition and DNA damage <span class="hlt">induced</span> by Cre recombinase in mammalian cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loonstra, A; Vooijs, M; Beverloo, H B; Allak, B A; van Drunen, E; Kanaar, R; Berns, A; Jonkers, J</p> <p>2001-07-31</p> <p>The use of Cre/loxP recombination in mammalian cells has expanded rapidly. We describe here that Cre expression in cultured mammalian cells may result in a markedly reduced proliferation and that this effect is dependent on the endonuclease activity of Cre. Chromosome analysis after Cre expression revealed numerous chromosomal aberrations and an increased number of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. Titration experiments in mouse embryo fibroblasts with a ligand-regulatable Cre-ER(T) show that toxicity is dependent on the level of Cre activity. Prolonged, low levels of Cre activity permit recombination without concomitant toxicity. This urges for a careful titration of Cre activity in conditional gene modification in mammalian cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1435098','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1435098"><span id="translatedtitle">Lipid <span class="hlt">exchange</span> between membranes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jähnig, F</p> <p>1984-01-01</p> <p>The <span class="hlt">exchange</span> of lipid molecules between vesicle bilayers in water and a monolayer forming at the water surface was investigated theoretically within the framework of thermodynamics. The total number of <span class="hlt">exchanged</span> molecules was found to depend on the bilayer curvature as expressed by the vesicle radius and on the boundary condition for <span class="hlt">exchange</span>, i.e., whether during <span class="hlt">exchange</span> the radius or the packing density of the vesicles remains constant. The boundary condition is determined by the rate of flip-flop within the bilayer relative to the rate of <span class="hlt">exchange</span> between bi- and monolayer. If flip-flop is fast, <span class="hlt">exchange</span> is independent of the vesicle radius; if flip-flop is slow, <span class="hlt">exchange</span> increases with the vesicle radius. Available experimental results agree with the detailed form of this dependence. When the theory was extended to <span class="hlt">exchange</span> between two bilayers of different curvature, the direction of <span class="hlt">exchange</span> was also determined by the curvatures and the boundary conditions for <span class="hlt">exchange</span>. Due to the dependence of the boundary conditions on flip-flop and, consequently, on membrane fluidity, <span class="hlt">exchange</span> between membranes may partially be regulated by membrane fluidity. PMID:6518251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948829','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948829"><span id="translatedtitle">Multiple Rad52-Mediated Homology-Directed Repair Mechanisms Are Required to Prevent Telomere Attrition-<span class="hlt">Induced</span> Senescence in Saccharomyces cerevisiae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>Most human somatic cells express insufficient levels of telomerase, which can result in telomere shortening and eventually senescence, both of which are hallmarks of ageing. Homology-directed repair (HDR) is important for maintaining proper telomere function in yeast and mammals. In Saccharomyces cerevisiae, Rad52 is required for almost all HDR mechanisms, and telomerase-null cells senesce faster in the absence of Rad52. However, its role in preventing accelerated senescence has been unclear. In this study, we make use of rad52 separation-of-function mutants to find that multiple Rad52-mediated HDR mechanisms are required to delay senescence, including break-<span class="hlt">induced</span> replication and sister <span class="hlt">chromatid</span> recombination. In addition, we show that misregulation of histone 3 lysine 56 acetylation, which is known to be defective in sister <span class="hlt">chromatid</span> recombination, also causes accelerated senescence. We propose a model where Rad52 is needed to repair telomere attrition-<span class="hlt">induced</span> replication stress. PMID:27428329</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20055003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20055003"><span id="translatedtitle">Approximate strip <span class="hlt">exchanging</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roy, Swapnoneel; Thakur, Ashok Kumar</p> <p>2008-01-01</p> <p>Genome rearrangements have been modelled by a variety of primitives such as reversals, transpositions, block moves and block interchanges. We consider such a genome rearrangement primitive Strip <span class="hlt">Exchanges</span>. Given a permutation, the challenge is to sort it by using minimum number of strip <span class="hlt">exchanges</span>. A strip <span class="hlt">exchanging</span> move interchanges the positions of two chosen strips so that they merge with other strips. The strip <span class="hlt">exchange</span> problem is to sort a permutation using minimum number of strip <span class="hlt">exchanges</span>. We present here the first non-trivial 2-approximation algorithm to this problem. We also observe that sorting by strip-<span class="hlt">exchanges</span> is fixed-parameter-tractable. Lastly we discuss the application of strip <span class="hlt">exchanges</span> in a different area Optical Character Recognition (OCR) with an example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24992337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24992337"><span id="translatedtitle">Meiosis-specific cohesin component, Stag3 is essential for maintaining centromere <span class="hlt">chromatid</span> cohesion, and required for DNA repair and synapsis between homologous chromosomes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hopkins, Jessica; Hwang, Grace; Jacob, Justin; Sapp, Nicklas; Bedigian, Rick; Oka, Kazuhiro; Overbeek, Paul; Murray, Steve; Jordan, Philip W</p> <p>2014-07-01</p> <p>Cohesins are important for chromosome structure and chromosome segregation during mitosis and meiosis. Cohesins are composed of two structural maintenance of chromosomes (SMC1-SMC3) proteins that form a V-shaped heterodimer structure, which is bridged by a α-kleisin protein and a stromal antigen (STAG) protein. Previous studies in mouse have shown that there is one SMC1 protein (SMC1β), two α-kleisins (RAD21L and REC8) and one STAG protein (STAG3) that are meiosis-specific. During meiosis, homologous chromosomes must recombine with one another in the context of a tripartite structure known as the synaptonemal complex (SC). From interaction studies, it has been shown that there are at least four meiosis-specific forms of cohesin, which together with the mitotic cohesin complex, are lateral components of the SC. STAG3 is the only meiosis-specific subunit that is represented within all four meiosis-specific cohesin complexes. In Stag3 mutant germ cells, the protein level of other meiosis-specific cohesin subunits (SMC1β, RAD21L and REC8) is reduced, and their localization to chromosome axes is disrupted. In contrast, the mitotic cohesin complex remains intact and localizes robustly to the meiotic chromosome axes. The instability of meiosis-specific cohesins observed in Stag3 mutants results in aberrant DNA repair processes, and disruption of synapsis between homologous chromosomes. Furthermore, mutation of Stag3 results in perturbation of pericentromeric heterochromatin clustering, and disruption of centromere cohesion between sister <span class="hlt">chromatids</span> during meiotic prophase. These defects result in early prophase I arrest and apoptosis in both male and female germ cells. The meiotic defects observed in Stag3 mutants are more severe when compared to single mutants for Smc1β, Rec8 and Rad21l, however they are not as severe as the Rec8, Rad21l double mutants. Taken together, our study demonstrates that STAG3 is required for the stability of all meiosis-specific cohesin</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9237771','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9237771"><span id="translatedtitle">Damage proneness <span class="hlt">induced</span> by genomic DNA demethylation in mammalian cells cultivated in vitro.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perticone, P; Gensabella, G; Cozzi, R</p> <p>1997-07-01</p> <p>Variations in the genomic DNA methylation level have been shown to be an epigenetic inheritable modification affecting, among other targets, the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) rate in mammalian cells in vitro. The inheritable increase in SCE rate in affected cell populations appears as a puzzling phenomenon in view of the well established relation between SCE and both mutagenesis and carcinogenesis. In the present work we demonstrate that, in a treated cell population, demethylation could be responsible for the inheritable induction of damage proneness affecting both damage induction and repair. Normal and ethionine or azacytidine treated Chinese hamster ovary cells, subclone K1 (CHO-K1), were challenged with UV light (UV) or mitomycin-C (MMC) at different times from the demethylating treatment. The SCE rate was measured with two main objects in view: (i) the induction of synergism or additivity in combined treatments, where mutagen (UV or MMC) pulse is supplied from 0 to 48 h after the end of the demethylating treatment; and (ii) the pattern of damage extinction, for the duration of up to six cell cycles after the end of the combined (demethylating agent + mutagen) treatment. Results indicate both a synergism in SCE induction by mutagens in demethylated cells even if supplied up to four cell cycles after the end of the demethylation treatment and a delay in recovery of <span class="hlt">induced</span> damage, compared with normally methylated cells. These data are discussed in the light of the supposed mechanism of SCE increase and of the possible biological significance in terms of mutagenesis and carcinogenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9237771','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9237771"><span id="translatedtitle">Damage proneness <span class="hlt">induced</span> by genomic DNA demethylation in mammalian cells cultivated in vitro.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perticone, P; Gensabella, G; Cozzi, R</p> <p>1997-07-01</p> <p>Variations in the genomic DNA methylation level have been shown to be an epigenetic inheritable modification affecting, among other targets, the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) rate in mammalian cells in vitro. The inheritable increase in SCE rate in affected cell populations appears as a puzzling phenomenon in view of the well established relation between SCE and both mutagenesis and carcinogenesis. In the present work we demonstrate that, in a treated cell population, demethylation could be responsible for the inheritable induction of damage proneness affecting both damage induction and repair. Normal and ethionine or azacytidine treated Chinese hamster ovary cells, subclone K1 (CHO-K1), were challenged with UV light (UV) or mitomycin-C (MMC) at different times from the demethylating treatment. The SCE rate was measured with two main objects in view: (i) the induction of synergism or additivity in combined treatments, where mutagen (UV or MMC) pulse is supplied from 0 to 48 h after the end of the demethylating treatment; and (ii) the pattern of damage extinction, for the duration of up to six cell cycles after the end of the combined (demethylating agent + mutagen) treatment. Results indicate both a synergism in SCE induction by mutagens in demethylated cells even if supplied up to four cell cycles after the end of the demethylation treatment and a delay in recovery of <span class="hlt">induced</span> damage, compared with normally methylated cells. These data are discussed in the light of the supposed mechanism of SCE increase and of the possible biological significance in terms of mutagenesis and carcinogenesis. PMID:9237771</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905725','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905725"><span id="translatedtitle">Minimal influence of G-protein null mutations on ozone-<span class="hlt">induced</span> changes in gene expression, foliar injury, gas <span class="hlt">exchange</span> and peroxidase activity in Arabidopsis thaliana L</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Booker, Fitzgerald; Burkey, Kent; Morgan, Patrick; Fiscus, Edwin; Jones, Alan</p> <p>2016-01-01</p> <p>Ozone (O3) uptake by plants leads to an increase in reactive oxygen species (ROS) in the intercellular space of leaves and <span class="hlt">induces</span> signalling processes reported to involve the membrane-bound heterotrimeric G-protein complex. Therefore, potential G-protein-mediated response mechanisms to O3 were compared between Arabidopsis thaliana L. lines with null mutations in the α- and β-subunits (gpa1-4, agb1-2 and gpa1-4/agb1-2) and Col-0 wild-type plants. Plants were treated with a range of O3 concentrations (5, 125, 175 and 300 nL L−1) for 1 and 2 d in controlled environment chambers. Transcript levels of GPA1, AGB1 and RGS1 transiently increased in Col-0 exposed to 125 nL L−1 O3 compared with the 5 nL L−1 control treatment. However, silencing of α and β G-protein genes resulted in little alteration of many processes associated with O3 injury, including the induction of ROS-signalling genes, increased leaf tissue ion leakage, decreased net photosynthesis and stomatal conductance, and increased peroxidase activity, especially in the leaf apoplast. These results indicated that many responses to O3 stress at physiological levels were not detectably influenced by α and β G-proteins. PMID:21988569</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1004628','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1004628"><span id="translatedtitle">Spin polarization and <span class="hlt">exchange</span> coupling of Cu and Mn atoms in paramagnetic CuMn diluted alloys <span class="hlt">induced</span> by a Co layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abes, M.; Arena, D.; Atkinson, D.; Tanner, B.K.; Charlton, T.R.; Langridge, S.; Hase, T.P.A.; Ali, M.; Marrows, C.H.; Hickey, B.J.; Neudert, Al; Hicken, R.J.; Wilkins, S.B.; Mirone, A.; Lebegue, S.</p> <p>2010-11-09</p> <p>Using the surface, interface, and element specificity of x-ray resonant magnetic scattering in combination with x-ray magnetic circular dichroism, we have spatially resolved the magnetic spin polarization, and the associated interface proximity effect, in a Mn-based high-susceptibility material close to a ferromagnetic Co layer. We have measured the magnetic polarization of Mn and Cu3d electrons in paramagnetic CuMn alloy layers in [Co/Cu(x)/CuMn/Cu(x)]{sub 20} multilayer samples with varying copper layer thicknesses from x=0 to 25 {angstrom}. The size of the Mn and CuL{sub 2,3} edge dichroism shows a decrease in the Mn-<span class="hlt">induced</span> polarization for increasing copper thickness indicating the dominant interfacial nature of the Cu and Mn spin polarization. The Mn polarization is much higher than that of Cu. Evidently, the Mn moment is a useful probe of the local spin density. Mn atoms appear to be coupled antiferromagnetically with the Co layer below x = 10 {angstrom} and ferromagnetically coupled above. In contrast, the interfacial Cu atoms remain ferromagnetically aligned to the Co layer for all thicknesses studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080009511','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080009511"><span id="translatedtitle">Nonsurvivable momentum <span class="hlt">exchange</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roder, Russell (Inventor); Ahronovich, Eliezer (Inventor); Davis, III, Milton C. (Inventor)</p> <p>2007-01-01</p> <p>A demiseable momentum <span class="hlt">exchange</span> system includes a base and a flywheel rotatably supported on the base. The flywheel includes a web portion defining a plurality of web openings and a rim portion. The momentum <span class="hlt">exchange</span> system further includes a motor for driving the flywheel and a cover for engaging the base to substantially enclose the flywheel. The system may also include components having a melting temperature below 1500 degrees Celsius. The momentum <span class="hlt">exchange</span> system is configured to demise on reentry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=recent+texts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drecent%2Btexts','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=recent+texts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drecent%2Btexts"><span id="translatedtitle">Text <span class="hlt">Exchange</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snyder, W. V.; Hanson, R. J.</p> <p>1986-01-01</p> <p>Text <span class="hlt">Exchange</span> System (TES) <span class="hlt">exchanges</span> and maintains organized textual information including source code, documentation, data, and listings. System consists of two computer programs and definition of format for information storage. Comprehensive program used to create, read, and maintain TES files. TES developed to meet three goals: First, easy and efficient <span class="hlt">exchange</span> of programs and other textual data between similar and dissimilar computer systems via magnetic tape. Second, provide transportable management system for textual information. Third, provide common user interface, over wide variety of computing systems, for all activities associated with text <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22304258','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22304258"><span id="translatedtitle">Magnetization jumps and <span class="hlt">exchange</span> bias <span class="hlt">induced</span> by a partially disordered antiferromagnetic state in (FeTiO{sub 3}){sub 0.9}-(Fe{sub 2}O{sub 3}){sub 0.1}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Song, P.; Li, G. K.; Ma, L. Zhen, C. M.; Hou, D. L.; Wang, W. H.; Liu, E. K.; Chen, J. L.; Wu, G. H.</p> <p>2014-06-07</p> <p>Magnetization jumps (MJs) and the <span class="hlt">exchange</span> bias (EB) effect are simultaneously observed in the mixed-spin oxide (FeTiO{sub 3}){sub 0.9}-(Fe{sub 2}O{sub 3}){sub 0.1} at 2.0 K. Dc and ac susceptibility measurements confirm a reentrant spin glass phase with a partially disordered antiferromagnetic (PDA) state below the irreversibility temperature (T{sub ir} = 60 K). Antiferromagnetic (AFM) Fe{sup 3+} clusters are nested in AFM Fe{sup 2+} lattices forming a triangular lattice, in which 2/3 of the magnetic moments order antiferromagnetically with each other leaving the remaining 1/3 “confused.” This geometric frustration in the triangular lattice leads to a PDA state that is the ground state of the AFM triangular configuration. The PDA state, in the presence of a critical trigger field, evolves into a ferromagnetic (FM) state, and <span class="hlt">induces</span> the AFM spins of the Fe{sup 2+} ions to enter a FM state, resulting in the MJs. Meanwhile, the FM spins of Fe{sup 2+} can serve as the pinned phase, and the AFM spins of Fe{sup 3+} can serve as the pinning phase, resulting in the EB effect. Thus, we point out that the PDA state is very likely to be at the origin of the MJs and the EB effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539331.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539331.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2012</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2012-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Directory+AND+Lab&pg=3&id=ED150112','ERIC'); return false;" href="http://eric.ed.gov/?q=Directory+AND+Lab&pg=3&id=ED150112"><span id="translatedtitle">Teachers' Centers <span class="hlt">Exchange</span> Directory.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lance, Jeanne; Kreitzman, Ruth</p> <p></p> <p>This directory has three major sections. The foreword is a brief essay describing the purpose of the Teachers' Centers <span class="hlt">Exchange</span>, the "network" of teachers' centers, and the reasons for compiling and publishing this directory. The second section gives descriptions of 78 teachers' centers in the <span class="hlt">Exchange</span>'s network. These descriptions highlight each…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865765','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865765"><span id="translatedtitle">Direct fired heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reimann, Robert C.; Root, Richard A.</p> <p>1986-01-01</p> <p>A gas-to-liquid heat <span class="hlt">exchanger</span> system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat <span class="hlt">exchanger</span> system is in a counterflow fluid arrangement which creates a more efficient heat transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539323.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539323.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2010</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2010-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED510312.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED510312.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2008</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2008-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=nurture&pg=7&id=EJ965736','ERIC'); return false;" href="http://eric.ed.gov/?q=nurture&pg=7&id=EJ965736"><span id="translatedtitle">Building Relationships through <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Primavera, Angi; Hall, Ellen</p> <p>2011-01-01</p> <p>From the moment of birth, children form and develop relationships with others in their world based on <span class="hlt">exchange</span>. Children recognize that engaging in such encounters offers them the opportunity to enter into a relationship with another individual and to nurture that relationship through the <span class="hlt">exchange</span> of messages and gifts, items and ideas. At Boulder…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED484664.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED484664.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2004</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed; Witte, Deborah, Ed.</p> <p>2004-01-01</p> <p>The Higher Education <span class="hlt">Exchange</span> is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society. Working in this tradition, the Higher Education <span class="hlt">Exchange</span> publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/992639','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992639"><span id="translatedtitle">Optimization of Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivan Catton</p> <p>2010-10-01</p> <p>The objective of this research is to develop tools to design and optimize heat <span class="hlt">exchangers</span> (HE) and compact heat <span class="hlt">exchangers</span> (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat <span class="hlt">exchanger</span>, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat <span class="hlt">exchanger</span>, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat <span class="hlt">exchanger</span>. The end product of this project is a computer code that can predict an optimal configuration for a heat <span class="hlt">exchanger</span> given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat <span class="hlt">exchangers</span> more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat <span class="hlt">exchanger</span> disign.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED497930.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED497930.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2005</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed; Witte, Deborah, Ed.</p> <p>2005-01-01</p> <p>The "Higher Education <span class="hlt">Exchange</span>" is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society. Working in this tradition, the "Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=increase+AND+environmental+AND+awareness&pg=7&id=EJ770022','ERIC'); return false;" href="http://eric.ed.gov/?q=increase+AND+environmental+AND+awareness&pg=7&id=EJ770022"><span id="translatedtitle">Environmental <span class="hlt">Exchange</span> Box</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moseley, Christine</p> <p>2003-01-01</p> <p>In this activity, teachers in one state create and share an "<span class="hlt">exchange</span> box" of environmental and cultural items with students of another state. The Environmental <span class="hlt">Exchange</span> Box activity enables teachers to improve students' skills in scientific inquiry and develop attitudes and values conducive to science learning such as wonder, curiosity, and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539343.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539343.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2011</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2011-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvS..18h4401N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvS..18h4401N"><span id="translatedtitle">Aberration corrected emittance <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nanni, E. A.; Graves, W. S.</p> <p>2015-08-01</p> <p>Full exploitation of emittance <span class="hlt">exchange</span> (EEX) requires aberration-free performance of a complex imaging system including active radio-frequency (rf) elements which can add temporal distortions. We investigate the performance of an EEX line where the <span class="hlt">exchange</span> occurs between two dimensions with normalized emittances which differ by multiple orders of magnitude. The transverse emittance is <span class="hlt">exchanged</span> into the longitudinal dimension using a double dogleg emittance <span class="hlt">exchange</span> setup with a five cell rf deflector cavity. Aberration correction is performed on the four most dominant aberrations. These include temporal aberrations that are corrected with higher order magnetic optical elements located where longitudinal and transverse emittance are coupled. We demonstrate aberration-free performance of an EEX line with emittances differing by four orders of magnitude, i.e., an initial transverse emittance of 1 pm-rad is <span class="hlt">exchanged</span> with a longitudinal emittance of 10 nm-rad.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8687133','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8687133"><span id="translatedtitle">Studies on genotoxicity of orally administered crocidolite asbestos in rats: implications for ingested asbestos <span class="hlt">induced</span> carcinogenesis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Varga, C; Pocsai, Z; Horváth, G; Timbrell, V</p> <p>1996-01-01</p> <p>The early genotoxic action of oral exposure to UICC crocidolite asbestos fibres was studied in different short-term tests. Fischer-344 rats were gavaged with 50 mg/b.w.kg untreated asbestos fibres and fibres which had been allowed to adsorb benzo(a)pyrene molecules from extremely low concentration (0.25-2.5 microg/ml) aqueous solutions. This system can be considered a model for the drinking of potable water contaminated by asbestos fibres together with biologically active organic micro-pollutants. The Ames Salmonella mutagenicity assay was performed on concentrated urine and serum samples of treated animals. The formation of micronuclei and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> was also studied in the bone marrow of the exposed rats. The micronucleus analysis indicated marginal genotoxic activity only upon treatment with crocidolite prepared from the solution of 1 microg/ml. A dose-dependent increase was, however, demonstrated in the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> frequency upon treatment with benzo(a)pyrene coated fibres. These experiments suggest the acute cogenotoxic activity of such fibres in orally exposed animals. PMID:8687133</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3826130','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3826130"><span id="translatedtitle">Microcystin-LR and Cylindrospermopsin <span class="hlt">Induced</span> Alterations in Chromatin Organization of Plant Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Máthé, Csaba; M-Hamvas, Márta; Vasas, Gábor</p> <p>2013-01-01</p> <p>Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-<span class="hlt">induced</span> changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins <span class="hlt">induce</span> the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister <span class="hlt">chromatid</span> segregation during mitosis. Thus, MCY and CYN are probably <span class="hlt">inducing</span> alterations of chromosome number. MCY <span class="hlt">induces</span> programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR <span class="hlt">induces</span> histone H3 hyperphosphorylation leading to incomplete <span class="hlt">chromatid</span> segregation and the formation of micronuclei. CYN <span class="hlt">induces</span> the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization. PMID:24084787</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005EPJB...45..155M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005EPJB...45..155M&link_type=ABSTRACT"><span id="translatedtitle">New Trends in Magnetic <span class="hlt">Exchange</span> Bias</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois</p> <p>2005-05-01</p> <p>The study of layered magnetic structures is one of the hottest topics in magnetism due to the growing attraction of applications in magnetic sensors and magnetic storage media, such as random access memory. For almost half a century, new discoveries have driven researchers to re-investigate magnetism in thin film structures. Phenomena such as giant magnetoresistance, tunneling magnetoresistance, <span class="hlt">exchange</span> bias and interlayer <span class="hlt">exchange</span> coupling led to new ideas to construct devices, based not only on semiconductors but on a variety of magnetic materials Upon cooling fine cobalt particles in a magnetic field through the Néel temperature of their outer antiferromagnetic oxide layer, Meiklejohn and Bean discovered <span class="hlt">exchange</span> bias in 1956. The <span class="hlt">exchange</span> bias effect through which an antiferromagnetic AF layer can cause an adjacent ferromagnetic F layer to develop a preferred direction of magnetization, is widely used in magnetoelectronics technology to pin the magnetization of a device reference layer in a desired direction. However, the origin and effects due to <span class="hlt">exchange</span> interaction across the interface between antiferromagneic and ferromagnetic layers are still debated after about fifty years of research, due to the extreme difficulty associated with the determination of the magnetic interfacial structure in F/AF bilayers. Indeed, in an AF/F bilayer system, the AF layer acts as “the invisible man” during conventional magnetic measurements and the presence of the <span class="hlt">exchange</span> coupling is evidenced indirectly through the unusual behavior of the adjacent F layer. Basically, the coercive field of the F layer increases in contact with the AF and, in some cases, its hysteresis loop is shifted by an amount called <span class="hlt">exchange</span> bias field. Thus, AF/F <span class="hlt">exchange</span> coupling generates a new source of anisotropy in the F layer. This <span class="hlt">induced</span> anisotropy strongly depends on basic features such as the magnetocrystalline anisotropy, crystallographic and spin structures, defects, domain patterns etc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864748','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864748"><span id="translatedtitle">Wound tube heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ecker, Amir L.</p> <p>1983-01-01</p> <p>What is disclosed is a wound tube heat <span class="hlt">exchanger</span> in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat <span class="hlt">exchanger</span>. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat <span class="hlt">exchange</span> bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5049207','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5049207"><span id="translatedtitle">Microtube strip heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Doty, F.D.</p> <p>1991-10-16</p> <p>This progress report is for the September--October 1991 quarter. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas <span class="hlt">exchangers</span>. These laminar-flow, microtube <span class="hlt">exchangers</span> exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat <span class="hlt">exchanger</span> performance promise to be of enormous significance in advanced engine designs and in cryogenics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1084225','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1084225"><span id="translatedtitle">Anion <span class="hlt">exchange</span> membrane</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Verkade, John G; Wadhwa, Kuldeep; Kong, Xueqian; Schmidt-Rohr, Klaus</p> <p>2013-05-07</p> <p>An anion <span class="hlt">exchange</span> membrane and fuel cell incorporating the anion <span class="hlt">exchange</span> membrane are detailed in which proazaphosphatrane and azaphosphatrane cations are covalently bonded to a sulfonated fluoropolymer support along with anionic counterions. A positive charge is dispersed in the aforementioned cations which are buried in the support to reduce the cation-anion interactions and increase the mobility of hydroxide ions, for example, across the membrane. The anion <span class="hlt">exchange</span> membrane has the ability to operate at high temperatures and in highly alkaline environments with high conductivity and low resistance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/915245','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/915245"><span id="translatedtitle">Heat and mass <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas</p> <p>2007-09-18</p> <p>A mass and heat <span class="hlt">exchanger</span> includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat <span class="hlt">exchange</span> fluid therethrough, wherein heat transfer occurs between the liquid and the heat <span class="hlt">exchange</span> fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873599','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873599"><span id="translatedtitle">Active microchannel heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA</p> <p>2001-01-01</p> <p>The present invention is an active microchannel heat <span class="hlt">exchanger</span> with an active heat source and with microchannel architecture. The microchannel heat <span class="hlt">exchanger</span> has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat <span class="hlt">exchanger</span> chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat <span class="hlt">exchanger</span> chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1183339','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1183339"><span id="translatedtitle">Anion <span class="hlt">exchange</span> polymer electrolytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Yu Seung; Kim, Dae Sik</p> <p>2015-06-02</p> <p>Anion <span class="hlt">exchange</span> polymer electrolytes that include guanidinium functionalized polymers may be used as membranes and binders for electrocatalysts in preparation of anodes for electrochemical cells such as solid alkaline fuel cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6639149','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6639149"><span id="translatedtitle">Greywater heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Holmberg, D.</p> <p>1983-11-21</p> <p>A kilowatt meter and water meter were installed to monitor pregreywater usage. The design considerations, the heat <span class="hlt">exchanger</span> construction and installation, and the monitoring of usage levels are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6233867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6233867"><span id="translatedtitle">Microtube Strip Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Doty, F.D.</p> <p>1990-12-27</p> <p>Doty Scientific (DSI) believes their Microtube-Strip Heat <span class="hlt">Exchanger</span> will contribute significantly to (a) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (b) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (c) high-efficiency cryogenic gas separation schemes for CO{sub 2} removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat <span class="hlt">exchangers</span> for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98%, and relative pressure drops below 0.1% with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat <span class="hlt">exchanger</span> bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat <span class="hlt">exchanger</span> bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat <span class="hlt">exchanger</span>; construct dies and fixtures for prototype heat <span class="hlt">exchanger</span>; construct 100 MTS modules; assemble 8-10 prototype MTS heat <span class="hlt">exchangers</span>; test prototype MTS heat <span class="hlt">exchanger</span>; and verify test through independent means. 7 refs., 9 figs. 1 tab. (CK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873481','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873481"><span id="translatedtitle">Radial flow heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Valenzuela, Javier</p> <p>2001-01-01</p> <p>A radial flow heat <span class="hlt">exchanger</span> (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat <span class="hlt">exchangers</span> may be stacked to achieve a modular heat <span class="hlt">exchange</span> assembly (300). Certain heat <span class="hlt">exchangers</span> in the assembly may be designed slightly differently than other heat <span class="hlt">exchangers</span> to address changes in fluid properties during transport through the heat <span class="hlt">exchanger</span>, so as to enhance overall thermal effectiveness of the assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5462064','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5462064"><span id="translatedtitle">Vacuum powered heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ruffolo, R.F.</p> <p>1986-06-24</p> <p>In an internal combustion engine including an oil lubrication system, a liquid cooling system, and an improved air intake system is described. The improved air intake system comprises: a housing including a first opening in one end, which opening is open to the atmosphere and a second opening comprising an air outlet opening in the other end open to the air intake manifold of the engine, a heat <span class="hlt">exchanger</span> positioned in the first opening. The heat <span class="hlt">exchanger</span> consists of a series of coils positioned in the flow path of the atmospheric air as it enters the housing, the heat <span class="hlt">exchanger</span> being fluidly connected to either the engine lubrication system or the cooling system to provide a warm heat source for the incoming air to the housing, acceleration means positioned in the housing downstream of the heat <span class="hlt">exchanger</span>, the acceleration means comprising a honeycomb structure positioned across the air intake flow path. The honey-comb structure includes a multitude of honey combed mini-venturi cells through which the heated air flows in an accelerated mode, a removable air filter positioned between the heat <span class="hlt">exchanger</span> and the acceleration means and a single opening provided in the housing through which the air filter can be passed and removed, and additional openings in the housing positioned downstream of the heat <span class="hlt">exchanger</span> and upstream of the air filter, the additional openings including removable flaps for opening and closing the openings to control the temperature of the air flowing through the housing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6688789','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6688789"><span id="translatedtitle">Heat <span class="hlt">exchange</span> device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Callison, G.</p> <p>1984-01-17</p> <p>A heat <span class="hlt">exchange</span> device is adapted to recover heat from the fire box of a wood burning stove or the like for heating ambient air in a room or other enclosed space. The heat <span class="hlt">exchange</span> device is adapted to mount in a recess in a stove top in place of a lid which is normally supplied with the stove. The device according to the invention includes heat <span class="hlt">exchange</span> means which extend into the fire box of the stove below the top surface thereof. The heat from the heat <span class="hlt">exchange</span> device is transmitted into a main cavity of the device where the heat is transferred to air forced through the main cavity by a blower mounted to an outside surface of the device. Air exit means are provided on a surface opposite to the surface on which the blower is mounted to provide a passage for heated air into the room or other enclosed space to be heated. The device may also include a top mounted isolated handle for ease in handling the device such as for moving from one area to another. In a second embodiment of the device, a high temperature heat <span class="hlt">exchange</span> glass plate is mounted on the surface of the device which is in contact with the fire box. Heat is transmitted by heat <span class="hlt">exchange</span> plate to the main cavity of the device where the air is heated and blown into the room as above.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12433103','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12433103"><span id="translatedtitle">Microscale continuous ion <span class="hlt">exchanger</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuban, Petr; Dasgupta, Purnendu K; Morris, Kavin A</p> <p>2002-11-01</p> <p>A microscale continuous ion <span class="hlt">exchanger</span> based on two liquid streams flowing in parallel is presented. The ion <span class="hlt">exchange</span> reaction occurs through diffusional transfer of molecules between the ion <span class="hlt">exchanger</span> phase and the eluent phase and is applied for conductivity suppression. Two approaches are demonstrated. In the first approach, a liquid ion <span class="hlt">exchanger</span> (i.e. a strongly basic compound, e.g., tetraoctylammonium hydroxide, or a secondary amine, e.g., Amberlite IA-2) is dissolved in an organic solvent immiscible with the aqueous eluent. The system allows for sensitive suppressed conductivity detection of various inorganic cations. When the weakly basic secondary amine is used, conductometric detection of heavy metals is possible. In the second approach, a suspension of finely ground ion-<span class="hlt">exchange</span> resin is used as the ion <span class="hlt">exchanger</span> phase. In this case, the suspension need not involve an organic solvent. Theoretical models and computations are presented along with experimental results. The potential of such a system as a chip-scale post-separation suppressor/reactor is evident.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5628..285T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5628..285T"><span id="translatedtitle">Cryptographic Combinatorial Securities <span class="hlt">Exchanges</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thorpe, Christopher; Parkes, David C.</p> <p></p> <p>We present a useful new mechanism that facilitates the atomic <span class="hlt">exchange</span> of many large baskets of securities in a combinatorial <span class="hlt">exchange</span>. Cryptography prevents information about the securities in the baskets from being exploited, enhancing trust. Our <span class="hlt">exchange</span> offers institutions who wish to trade large positions a new alternative to existing methods of block trading: they can reduce transaction costs by taking advantage of other institutions’ available liquidity, while third party liquidity providers guarantee execution—preserving their desired portfolio composition at all times. In our <span class="hlt">exchange</span>, institutions submit encrypted orders which are crossed, leaving a “remainder”. The <span class="hlt">exchange</span> proves facts about the portfolio risk of this remainder to third party liquidity providers without revealing the securities in the remainder, the knowledge of which could also be exploited. The third parties learn either (depending on the setting) the portfolio risk parameters of the remainder itself, or how their own portfolio risk would change if they were to incorporate the remainder into a portfolio they submit. In one setting, these third parties submit bids on the commission, and the winner supplies necessary liquidity for the entire <span class="hlt">exchange</span> to clear. This guaranteed clearing, coupled with external price discovery from the primary markets for the securities, sidesteps difficult combinatorial optimization problems. This latter method of proving how taking on the remainder would change risk parameters of one’s own portfolio, without revealing the remainder’s contents or its own risk parameters, is a useful protocol of independent interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24957012','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24957012"><span id="translatedtitle">Controllable conversion of plasmonic Cu2-xS nanoparticles to Au2S by cation <span class="hlt">exchange</span> and electron beam <span class="hlt">induced</span> transformation of Cu2-xS-Au2S core/shell nanostructures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xianliang; Liu, Xin; Zhu, Dewei; Swihart, Mark T</p> <p>2014-08-01</p> <p>Self-doped Cu2-xS nanocrystals (NCs) were converted into monodisperse Cu2-xS-Au2S NCs of tunable composition, including pure Au2S, by cation <span class="hlt">exchange</span>. The near-infrared (NIR) localized surface plasmon resonance (LSPR) was dampened and red-shifted with increasing Au content. Cation <span class="hlt">exchange</span> was accompanied by elimination of cation vacancies and a change in crystal structure. Partially <span class="hlt">exchanged</span> Cu2-xS-Au2S core/shell structures evolved to dumbbell-like structures under electron irradiation in the transmission electron microscope (TEM).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22391356','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22391356"><span id="translatedtitle">Charge-<span class="hlt">exchange</span> reaction by Reggeon <span class="hlt">exchange</span> and W{sup +}W{sup −}-fusion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schicker, R.</p> <p>2015-04-10</p> <p>Charge-<span class="hlt">exchange</span> reactions at high energies are examined. The existing cross section data on the Reggeon <span class="hlt">induced</span> reaction pp → n + Δ{sup ++} taken at the ZGS and ISR accelerators are extrapolated to the energies of the RHIC and LHC colliders. The interest in the charge-<span class="hlt">exchange</span> reaction <span class="hlt">induced</span> by W{sup ±}-fusion is presented, and the corresponding QCD-background is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvA..90c2705D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvA..90c2705D"><span id="translatedtitle">Spin-noise correlations and spin-noise <span class="hlt">exchange</span> driven by low-field spin-<span class="hlt">exchange</span> collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dellis, A. T.; Loulakis, M.; Kominis, I. K.</p> <p>2014-09-01</p> <p>The physics of spin-<span class="hlt">exchange</span> collisions have fueled several discoveries in fundamental physics and numerous applications in medical imaging and nuclear magnetic resonance. We report on the experimental observation and theoretical justification of spin-noise <span class="hlt">exchange</span>, the transfer of spin noise from one atomic species to another. The signature of spin-noise <span class="hlt">exchange</span> is an increase of the total spin-noise power at low magnetic fields, on the order of 1 mG, where the two-species spin-noise resonances overlap. The underlying physical mechanism is the two-species spin-noise correlation <span class="hlt">induced</span> by spin-<span class="hlt">exchange</span> collisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6905451','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6905451"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-03-18</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5030222','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5030222"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-02-28</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7041653','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7041653"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-03-18</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summary herein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/691514','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/691514"><span id="translatedtitle">Downhole heat <span class="hlt">exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Culver, G.; Lund, J.W.</p> <p>1999-09-01</p> <p>The downhole heat <span class="hlt">exchanger</span> (DHE) eliminates the problem of disposal of geothermal fluid, since only heat is taken from the well. The <span class="hlt">exchanger</span> consists of a system of pipes or tubes suspended in the well through which clean secondary water is pumped or allowed to circulate by natural convection. These systems offer substantial economic savings over surface heat <span class="hlt">exchangers</span> where a single-well system is adequate (typically less than 0.8 MWt, with well depths up to about 500 ft) and may be economical under certain conditions at well depths to 1500 ft. Several designs have proven successful; but, the most popular are a simple hairpin loop or multiple loops of iron pipe (similar to the tubes in a U-tube and shell <span class="hlt">exchanger</span>) extending to near the well bottom. An experimental design consisting of multiple small tubes with headers at each end suspended just below the water surface appears to offer economic and heating capacity advantages. The paper describes design and construction details and New Zealand`s experience with downhole heat <span class="hlt">exchangers</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdWR...94..400C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdWR...94..400C"><span id="translatedtitle">Impact of watershed topography on hyporheic <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caruso, Alice; Ridolfi, Luca; Boano, Fulvio</p> <p>2016-08-01</p> <p>Among the interactions between surface water bodies and aquifers, hyporheic <span class="hlt">exchange</span> has been recognized as a key process for nutrient cycling and contaminant transport. Even though hyporheic <span class="hlt">exchange</span> is strongly controlled by groundwater discharge, our understanding of the impact of the regional groundwater flow on hyporheic fluxes is still limited because of the complexity arising from the multi-scale nature of these interactions. In this work, we investigate the role of watershed topography on river-aquifer interactions by way of a semi-analytical model, in which the landscape topography is used to approximate the groundwater head distribution. The analysis of a case study shows how the complex topographic structure is the direct cause of a substantial spatial variability of the aquifer-river <span class="hlt">exchange</span>. Groundwater upwelling along the river corridor is estimated and its influence on the hyporheic zone is discussed. In particular, the fragmentation of the hyporeic corridor <span class="hlt">induced</span> by groundwater discharge at the basin scale is highlighted.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7050066','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7050066"><span id="translatedtitle">In vitro effect of fenthion on human lymphocytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rani, M.V.U. ); Rao, M.S. )</p> <p>1991-08-01</p> <p>Fenthion is an organophosphorus insecticide which is extensively used in control of leaf hoppers, cutworms, mites on vegetable crops. It has been reported that organophosphorus pesticides cause a significant increase in sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in mammalian cell lines. A significant increase of chromosomal aberrations has been reported in rural population exposed to pesticides. Organosphosphorus pesticides malathion, diazinon, dimethoate, phosdrin and dursban <span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in human lymphoid cells. <span class="hlt">Exchange</span> type of aberration has been reported in fluoriculturist who were exposed to organophosphorus, organochlorine pesticides. In the present investigation an attempt has been made to evaluate the cytogenetic effect of fenthion in human lymphocyte cultures in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008919','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008919"><span id="translatedtitle">Microgravity condensing heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)</p> <p>2011-01-01</p> <p>A heat <span class="hlt">exchanger</span> having a plurality of heat <span class="hlt">exchanging</span> aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat <span class="hlt">exchanging</span> fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained air is drawn from the capillary spaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863123','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863123"><span id="translatedtitle">Modular heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Culver, Donald W.</p> <p>1978-01-01</p> <p>A heat <span class="hlt">exchanger</span> for use in nuclear reactors includes a heat <span class="hlt">exchange</span> tube bundle formed from similar modules each having a hexagonal shroud containing a large number of thermally conductive tubes which are connected with inlet and outlet headers at opposite ends of each module, the respective headers being adapted for interconnection with suitable inlet and outlet manifold means. In order to adapt the heat <span class="hlt">exchanger</span> for operation in a high temperature and high pressure environment and to provide access to all tube ports at opposite ends of the tube bundle, a spherical tube sheet is arranged in sealed relation across the chamber with an elongated duct extending outwardly therefrom to provide manifold means for interconnection with the opposite end of the tube bundle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048277','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048277"><span id="translatedtitle">Ion <span class="hlt">exchange</span> phenomena</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bourg, I.C.; Sposito, G.</p> <p>2011-05-01</p> <p>Ion <span class="hlt">exchange</span> phenomena involve the population of readily <span class="hlt">exchangeable</span> ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion <span class="hlt">exchange</span> phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5496945','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5496945"><span id="translatedtitle">Stimulation-dependent myocardial calcium uptake into slowly <span class="hlt">exchangeable</span> compartments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fintel, M.; Langer, G.A.</p> <p>1986-03-01</p> <p>Myocardial calcium uptake into slowly <span class="hlt">exchangeable</span> sites was increased in response to beating following a period of prolonged quiescence (> 1 hr). Net calcium uptake was measured in rabbit interventricular septa using the /sup 45/Ca washout technique. The maximal increment of slowly <span class="hlt">exchangeable</span> calcium <span class="hlt">induced</span> by beating was 20 +/- 2% of calcium uptake during quiescence. The increment in calcium uptake <span class="hlt">induced</span> by 282 beats in 10 minutes did not differ from the increment <span class="hlt">induced</span> by 60 beats but was significantly greater than the increment <span class="hlt">induced</span> by 35 and 15 beats. The total number of beats rather than the frequency of stimulation appeared to be the most critical factor which determined the increment in calcium uptake. Based on the increment of 0.12 +/- 0.02 mmoles/kg dry weight obtained when 15 beats occurred in 10 minutes, the minimum amount of calcium which entered slowly <span class="hlt">exchangeable</span> sites per beat was calculated to be 1 ..mu..mol/kg wet weight. The increment in slowly <span class="hlt">exchangeable</span> calcium <span class="hlt">induced</span> by beating was not affected by ryanodine but was inhibited by the metabolic inhibitor CCCP. In conclusion, a net increment in slowly <span class="hlt">exchangeable</span> calcium occurs when beating is resumed following a period of prolonged quiescence. This suggests that calcium influx exceeds efflux transiently, under these conditions, and that slowly <span class="hlt">exchangeable</span> sites represent an important mechanism by which a fraction of incoming calcium is buffered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=228049','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=228049"><span id="translatedtitle"><span class="hlt">Exchangers</span> man the pumps: Functional interplay between proton pumps and proton-coupled Ca(2+) <span class="hlt">exchangers</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Tonoplast-localised proton-coupled Ca(2+) transporters encoded by cation/H(+) <span class="hlt">exchanger</span> (CAX) genes play a critical role in sequestering Ca(2+) into the vacuole. These transporters may function in coordination with Ca(2+) release channels, to shape stimulus-<span class="hlt">induced</span> cytosolic Ca(2+) elevations. Recen...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012957','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012957"><span id="translatedtitle">Microscale Regenerative Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred</p> <p>2006-01-01</p> <p>The device described herein is designed primarily for use as a regenerative heat <span class="hlt">exchanger</span> in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat <span class="hlt">exchanger</span> (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150015577','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150015577"><span id="translatedtitle">Alert <span class="hlt">Exchange</span> Process Protocol</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Groen, Frank</p> <p>2015-01-01</p> <p>The National Aeronautics and Space Administration of the United States of America (NASA), and the European Space Agency (ESA), and the Japanese Aerospace Exploration Agency (JAXA), acknowledging that NASA, ESA and JAXA have a mutual interest in <span class="hlt">exchanging</span> Alerts and Alert Status Lists to enhance the information base for each system participant while fortifying the general level of cooperation between the policy agreement subscribers, and each Party will <span class="hlt">exchange</span> Alert listings on regular basis and detailed Alert information on a need to know basis to the extent permitted by law.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005075','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005075"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> panel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Warburton, Robert E. (Inventor); Cuva, William J. (Inventor)</p> <p>2005-01-01</p> <p>The present invention relates to a heat <span class="hlt">exchanger</span> panel which has broad utility in high temperature environments. The heat <span class="hlt">exchanger</span> panel has a first panel, a second panel, and at least one fluid containment device positioned intermediate the first and second panels. At least one of the first panel and the second panel have at least one feature on an interior surface to accommodate the at least one fluid containment device. In a preferred embodiment, each of the first and second panels is formed from a high conductivity, high temperature composite material. Also, in a preferred embodiment, the first and second panels are joined together by one or more composite fasteners.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27014627','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27014627"><span id="translatedtitle">Three-Color Chromosome Painting as Seen through the Eyes of mFISH: Another Look at Radiation-<span class="hlt">Induced</span> <span class="hlt">Exchanges</span> and Their Conversion to Whole-Genome Equivalency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loucas, Bradford D; Shuryak, Igor; Cornforth, Michael N</p> <p>2016-01-01</p> <p>Whole-chromosome painting (WCP) typically involves the fluorescent staining of a small number of chromosomes. Consequently, it is capable of detecting only a fraction of <span class="hlt">exchanges</span> that occur among the full complement of chromosomes in a genome. Mathematical corrections are commonly applied to WCP data in order to extrapolate the frequency of <span class="hlt">exchanges</span> occurring in the entire genome [whole-genome equivalency (WGE)]. However, the reliability of WCP to WGE extrapolations depends on underlying assumptions whose conditions are seldom met in actual experimental situations, in particular the presumed absence of complex <span class="hlt">exchanges</span>. Using multi-fluor fluorescence in situ hybridization (mFISH), we analyzed the induction of simple <span class="hlt">exchanges</span> produced by graded doses of (137)Cs gamma rays (0-4 Gy), and also 1.1 GeV (56)Fe ions (0-1.5 Gy). In order to represent cytogenetic damage as it would have appeared to the observer following standard three-color WCP, all mFISH information pertaining to <span class="hlt">exchanges</span> that did not specifically involve chromosomes 1, 2, or 4 was ignored. This allowed us to reconstruct dose-responses for three-color apparently simple (AS) <span class="hlt">exchanges</span>. Using extrapolation methods similar to those derived elsewhere, these were expressed in terms of WGE for comparison to mFISH data. Based on AS events, the extrapolated frequencies systematically overestimated those actually observed by mFISH. For gamma rays, these errors were practically independent of dose. When constrained to a relatively narrow range of doses, the WGE corrections applied to both (56)Fe and gamma rays predicted genome-equivalent damage with a level of accuracy likely sufficient for most applications. However, the apparent accuracy associated with WCP to WGE corrections is both fortuitous and misleading. This is because (in normal practice) such corrections can only be applied to AS <span class="hlt">exchanges</span>, which are known to include complex aberrations in the form of pseudosimple <span class="hlt">exchanges</span>. When WCP to WGE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27014627','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27014627"><span id="translatedtitle">Three-Color Chromosome Painting as Seen through the Eyes of mFISH: Another Look at Radiation-<span class="hlt">Induced</span> <span class="hlt">Exchanges</span> and Their Conversion to Whole-Genome Equivalency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loucas, Bradford D; Shuryak, Igor; Cornforth, Michael N</p> <p>2016-01-01</p> <p>Whole-chromosome painting (WCP) typically involves the fluorescent staining of a small number of chromosomes. Consequently, it is capable of detecting only a fraction of <span class="hlt">exchanges</span> that occur among the full complement of chromosomes in a genome. Mathematical corrections are commonly applied to WCP data in order to extrapolate the frequency of <span class="hlt">exchanges</span> occurring in the entire genome [whole-genome equivalency (WGE)]. However, the reliability of WCP to WGE extrapolations depends on underlying assumptions whose conditions are seldom met in actual experimental situations, in particular the presumed absence of complex <span class="hlt">exchanges</span>. Using multi-fluor fluorescence in situ hybridization (mFISH), we analyzed the induction of simple <span class="hlt">exchanges</span> produced by graded doses of (137)Cs gamma rays (0-4 Gy), and also 1.1 GeV (56)Fe ions (0-1.5 Gy). In order to represent cytogenetic damage as it would have appeared to the observer following standard three-color WCP, all mFISH information pertaining to <span class="hlt">exchanges</span> that did not specifically involve chromosomes 1, 2, or 4 was ignored. This allowed us to reconstruct dose-responses for three-color apparently simple (AS) <span class="hlt">exchanges</span>. Using extrapolation methods similar to those derived elsewhere, these were expressed in terms of WGE for comparison to mFISH data. Based on AS events, the extrapolated frequencies systematically overestimated those actually observed by mFISH. For gamma rays, these errors were practically independent of dose. When constrained to a relatively narrow range of doses, the WGE corrections applied to both (56)Fe and gamma rays predicted genome-equivalent damage with a level of accuracy likely sufficient for most applications. However, the apparent accuracy associated with WCP to WGE corrections is both fortuitous and misleading. This is because (in normal practice) such corrections can only be applied to AS <span class="hlt">exchanges</span>, which are known to include complex aberrations in the form of pseudosimple <span class="hlt">exchanges</span>. When WCP to WGE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791380','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791380"><span id="translatedtitle">Three-Color Chromosome Painting as Seen through the Eyes of mFISH: Another Look at Radiation-<span class="hlt">Induced</span> <span class="hlt">Exchanges</span> and Their Conversion to Whole-Genome Equivalency</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Loucas, Bradford D.; Shuryak, Igor; Cornforth, Michael N.</p> <p>2016-01-01</p> <p>Whole-chromosome painting (WCP) typically involves the fluorescent staining of a small number of chromosomes. Consequently, it is capable of detecting only a fraction of <span class="hlt">exchanges</span> that occur among the full complement of chromosomes in a genome. Mathematical corrections are commonly applied to WCP data in order to extrapolate the frequency of <span class="hlt">exchanges</span> occurring in the entire genome [whole-genome equivalency (WGE)]. However, the reliability of WCP to WGE extrapolations depends on underlying assumptions whose conditions are seldom met in actual experimental situations, in particular the presumed absence of complex <span class="hlt">exchanges</span>. Using multi-fluor fluorescence in situ hybridization (mFISH), we analyzed the induction of simple <span class="hlt">exchanges</span> produced by graded doses of 137Cs gamma rays (0–4 Gy), and also 1.1 GeV 56Fe ions (0–1.5 Gy). In order to represent cytogenetic damage as it would have appeared to the observer following standard three-color WCP, all mFISH information pertaining to <span class="hlt">exchanges</span> that did not specifically involve chromosomes 1, 2, or 4 was ignored. This allowed us to reconstruct dose–responses for three-color apparently simple (AS) <span class="hlt">exchanges</span>. Using extrapolation methods similar to those derived elsewhere, these were expressed in terms of WGE for comparison to mFISH data. Based on AS events, the extrapolated frequencies systematically overestimated those actually observed by mFISH. For gamma rays, these errors were practically independent of dose. When constrained to a relatively narrow range of doses, the WGE corrections applied to both 56Fe and gamma rays predicted genome-equivalent damage with a level of accuracy likely sufficient for most applications. However, the apparent accuracy associated with WCP to WGE corrections is both fortuitous and misleading. This is because (in normal practice) such corrections can only be applied to AS <span class="hlt">exchanges</span>, which are known to include complex aberrations in the form of pseudosimple <span class="hlt">exchanges</span>. When WCP to WGE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=china+AND+geography&pg=6&id=EJ346259','ERIC'); return false;" href="http://eric.ed.gov/?q=china+AND+geography&pg=6&id=EJ346259"><span id="translatedtitle">Visiting Scholar <span class="hlt">Exchange</span> Reports.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rubin, Kyna, Ed.</p> <p>1986-01-01</p> <p>Provides reports of four United States scholars who visited China as part of the Visiting Scholar <span class="hlt">Exchange</span> Program. The titles of the reports are (1) "China Journey: A Political Scientist's Look at Yan'an," (2) "The Social Consequences of Land Reclamation in Chinese Coastal Ecosystems," (3) "Anthropology Lectures in South China," and (4) "The Use…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED387394.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED387394.pdf"><span id="translatedtitle">Currency <span class="hlt">Exchange</span> Rates.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Siler, Carl R.</p> <p></p> <p>This curriculum unit of the Muncie (Indiana) Southside High School is to simulate the dynamics of foreign currency <span class="hlt">exchange</span> rates from the perspectives of: (1) a major U.S. corporation, ABB Power T & D Company, Inc., of Muncie, Indiana, a manufacturer of large power transformers for the domestic and foreign markets; and (2) individual consumers…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1225345','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1225345"><span id="translatedtitle">Technology Performance <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2015-09-01</p> <p>To address the need for accessible, high-quality data, the Department of Energy has developed the Technology Performance <span class="hlt">Exchange</span> (TPEx). TPEx enables technology suppliers, third-party testing laboratories, and other entities to share product performance data. These data are automatically transformed into a format that technology evaluators can easily use in their energy modeling assessments to inform procurement decisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED560889.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED560889.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2014</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2014-01-01</p> <p>Research shows that not only does higher education not see the public; when the public, in turn, looks at higher education, it sees mostly malaise, inefficiencies, expense, and unfulfilled promises. Yet, the contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" tell of bright spots in higher education where experiments in working…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED510123.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED510123.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2009-01-01</p> <p>This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education <span class="hlt">Exchange</span> (HEX). She reiterates Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological conundrum of "knowledge produced…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539321.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539321.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2009</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2009-01-01</p> <p>This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education <span class="hlt">Exchange</span> (HEX). She reiterates Kettering's president David Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED497931.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED497931.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span> 2006</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2006-01-01</p> <p>Contributors to this issue of the Higher Education <span class="hlt">Exchange</span> debate the issues around knowledge production, discuss the acquisition of deliberative skills for democracy, and examine how higher education prepares, or does not prepare, students for citizenship roles. Articles include: (1) "Foreword" (Deborah Witte); (2) "Knowledge, Judgment and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=convection&pg=5&id=EJ452044','ERIC'); return false;" href="http://eric.ed.gov/?q=convection&pg=5&id=EJ452044"><span id="translatedtitle">Nature's Heat <span class="hlt">Exchangers</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Barnes, George</p> <p>1991-01-01</p> <p>Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat <span class="hlt">exchange</span> in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5758003','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5758003"><span id="translatedtitle">Chimney heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whiteley, I.C.</p> <p>1981-09-01</p> <p>A heat <span class="hlt">exchanger</span> for installation on the top of a chimney of a building includes a housing having a lower end receiving the top of the chimney and an upper end with openings permitting the escape of effluent from the chimney and a heat <span class="hlt">exchanger</span> assembly disposed in the housing including a central chamber and a spirally arranged duct network defining an effluent spiral path between the top of the chimney and the central chamber and a fresh air spiral path between an inlet disposed at the lower end of the housing and the central chamber, the effluent and fresh air spiral paths being in heat <span class="hlt">exchange</span> relationship such that air passing through the fresh air spiral path is heated by hot effluent gases passing upward through the chimney and the effluent spiral path for use in heating the building. A pollution trap can be disposed in the central chamber of the heat <span class="hlt">exchanger</span> assembly for removing pollutants from the effluent, the pollution trap including a rotating cage carrying pumice stones for absorbing pollutants from the effluent with the surface of the pumice gradually ground off to reveal fresh stone as the cage rotates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5374745','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5374745"><span id="translatedtitle">Estimate <span class="hlt">exchanger</span> vibration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nieh, C.D.; Zengyan, H.</p> <p>1986-04-01</p> <p>Based on the classical beam theory, a simple method for calculating the natural frequency of unequally spanned tubes is presented. The method is suitable for various boundary conditions. Accuracy of the calculations is sufficient for practical applications. This method will help designers and operators estimate the vibration of tubular <span class="hlt">exchangers</span>. In general, there are three reasons why a tube vibrates in cross flow: vortex shedding, fluid elasticity and turbulent buffeting. No matter which is the cause, the basic reason is that the frequency of exciting force is approximately the same as or equal to the natural frequency of the tube. To prevent the heat <span class="hlt">exchanger</span> from vibrating, it is necessary to select correctly the shell-side fluid velocity so that the frequency of exciting force is different from the natural frequency of the tube, or to vary the natural frequency of the heat <span class="hlt">exchanger</span> tube. So precisely determining the natural frequency of the heat <span class="hlt">exchanger</span>, especially its foundational frequency under various supporting conditions, is of significance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED114185.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED114185.pdf"><span id="translatedtitle">Idea <span class="hlt">Exchange</span>: Volunteerism.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ryan, Jamice, Ed.</p> <p>1974-01-01</p> <p>This issue of "Idea <span class="hlt">Exchange</span>" which focuses on the volunteer in education programs includes a variety of materials related to volunteer experiences and viewpoints: (1) a handbook for volunteer coordinators which discusses the coordinator's role, the recruiting and interviewing of volunteers, and the essentials of volunteer placement and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20689731','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20689731"><span id="translatedtitle">In vivo cytogenetic studies on aspartame.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alsuhaibani, Entissar S</p> <p>2010-01-01</p> <p>Aspartame (a-Laspartyl-L-phenylalanine 1-methylester) is a dipeptide low-calorie artificial sweetener that is widely used as a nonnutritive sweetener in foods and drinks. The safety of aspartame and its metabolic breakdown products (phenylalanine, aspartic acid and methanol) was investigated in vivo using chromosomal aberration (CA) test and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) test in the bone marrow cells of mice. Swiss Albino male mice were exposed to aspartame (3.5, 35, 350 mg/kg body weight). Bone marrow cells isolated from femora were analyzed for chromosome aberrations and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. Treatment with aspartame <span class="hlt">induced</span> dose dependently chromosome aberrations at all concentrations while it did not <span class="hlt">induce</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. On the other hand, aspartame did not decrease the mitotic index (MI). However, statistical analysis of the results show that aspartame is not significantly genotoxic at low concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/934585','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/934585"><span id="translatedtitle">Chemical <span class="hlt">exchange</span> program analysis.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Waffelaert, Pascale</p> <p>2007-09-01</p> <p>As part of its EMS, Sandia performs an annual environmental aspects/impacts analysis. The purpose of this analysis is to identify the environmental aspects associated with Sandia's activities, products, and services and the potential environmental impacts associated with those aspects. Division and environmental programs established objectives and targets based on the environmental aspects associated with their operations. In 2007 the most significant aspect identified was Hazardous Materials (Use and Storage). The objective for Hazardous Materials (Use and Storage) was to improve chemical handling, storage, and on-site movement of hazardous materials. One of the targets supporting this objective was to develop an effective chemical <span class="hlt">exchange</span> program, making a business case for it in FY07, and fully implementing a comprehensive chemical <span class="hlt">exchange</span> program in FY08. A Chemical <span class="hlt">Exchange</span> Program (CEP) team was formed to implement this target. The team consists of representatives from the Chemical Information System (CIS), Pollution Prevention (P2), the HWMF, Procurement and the Environmental Management System (EMS). The CEP Team performed benchmarking and conducted a life-cycle analysis of the current management of chemicals at SNL/NM and compared it to Chemical <span class="hlt">Exchange</span> alternatives. Those alternatives are as follows: (1) Revive the 'Virtual' Chemical <span class="hlt">Exchange</span> Program; (2) Re-implement a 'Physical' Chemical <span class="hlt">Exchange</span> Program using a Chemical Information System; and (3) Transition to a Chemical Management Services System. The analysis and benchmarking study shows that the present management of chemicals at SNL/NM is significantly disjointed and a life-cycle or 'Cradle-to-Grave' approach to chemical management is needed. This approach must consider the purchasing and maintenance costs as well as the cost of ultimate disposal of the chemicals and materials. A chemical <span class="hlt">exchange</span> is needed as a mechanism to re-apply chemicals on site. This will not only reduce the quantity of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005EPJB...45..155M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005EPJB...45..155M"><span id="translatedtitle">New Trends in Magnetic <span class="hlt">Exchange</span> Bias</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois</p> <p>2005-05-01</p> <p>The study of layered magnetic structures is one of the hottest topics in magnetism due to the growing attraction of applications in magnetic sensors and magnetic storage media, such as random access memory. For almost half a century, new discoveries have driven researchers to re-investigate magnetism in thin film structures. Phenomena such as giant magnetoresistance, tunneling magnetoresistance, <span class="hlt">exchange</span> bias and interlayer <span class="hlt">exchange</span> coupling led to new ideas to construct devices, based not only on semiconductors but on a variety of magnetic materials Upon cooling fine cobalt particles in a magnetic field through the Néel temperature of their outer antiferromagnetic oxide layer, Meiklejohn and Bean discovered <span class="hlt">exchange</span> bias in 1956. The <span class="hlt">exchange</span> bias effect through which an antiferromagnetic AF layer can cause an adjacent ferromagnetic F layer to develop a preferred direction of magnetization, is widely used in magnetoelectronics technology to pin the magnetization of a device reference layer in a desired direction. However, the origin and effects due to <span class="hlt">exchange</span> interaction across the interface between antiferromagneic and ferromagnetic layers are still debated after about fifty years of research, due to the extreme difficulty associated with the determination of the magnetic interfacial structure in F/AF bilayers. Indeed, in an AF/F bilayer system, the AF layer acts as “the invisible man” during conventional magnetic measurements and the presence of the <span class="hlt">exchange</span> coupling is evidenced indirectly through the unusual behavior of the adjacent F layer. Basically, the coercive field of the F layer increases in contact with the AF and, in some cases, its hysteresis loop is shifted by an amount called <span class="hlt">exchange</span> bias field. Thus, AF/F <span class="hlt">exchange</span> coupling generates a new source of anisotropy in the F layer. This <span class="hlt">induced</span> anisotropy strongly depends on basic features such as the magnetocrystalline anisotropy, crystallographic and spin structures, defects, domain patterns etc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/191747','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/191747"><span id="translatedtitle">Composite ion <span class="hlt">exchange</span> materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Amarasinghe, S.; Zook, L.; Leddy, J.</p> <p>1994-12-31</p> <p>Composite ion <span class="hlt">exchange</span> materials can be formed by sorbing ion <span class="hlt">exchange</span> polymers on inert, high surface area substrates. In general, the flux of ions and molecules through these composites, as measured electrochemically, increases as the ratio of the surface area of the substrate increases relative to the volume of the ion <span class="hlt">exchanger</span>. This suggests that fields and gradients established at the interface between the ion <span class="hlt">exchanger</span> and substrate are important in determining the transport characteristics of the composites. Here, the authors will focus on composites formed with a cation <span class="hlt">exchange</span> polymer, Nafion, and two different types of microbeads: polystyrene microspheres and polystyrene coated magnetic microbeads. For the polystyrene microbeads, scanning electron micrographs suggest the beads cluster in a self-similar manner, independent of the bead diameter. Flux of Ru(NH3)63+ through the composites was studied as a function of bead fraction, bead radii, and fixed surface area with mixed bead sizes. Flux was well modeled by surface diffusion along a fractal interface. Magnetic composites were formed with columns of magnetic microbeads normal to the electrode surface. Flux of Ru(NH3)63+ through these composites increased exponentially with bead fraction. For electrolyses, the difference in the molar magnetic susceptibility of the products and reactants, Dcm, tends to be non-zero. For seven redox reactions, the ratio of the flux through the magnetic composites to the flux through a Nafion film increases monotonically with {vert_bar}Dcm{vert_bar}, with enhancements as large as thirty-fold. For reversible species, the electrolysis potential through the magnetic composites is 35 mV positive of that for the Nafion films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001428','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001428"><span id="translatedtitle">Counterflow Regolith Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zubrin, Robert; Jonscher, Peter</p> <p>2013-01-01</p> <p>A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat <span class="hlt">exchanger</span> (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat <span class="hlt">exchanger</span> with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat <span class="hlt">exchanger</span> close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat <span class="hlt">exchange</span> to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat <span class="hlt">exchanger</span> itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6562578','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6562578"><span id="translatedtitle">A corrosive resistant heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Richlen, S.L.</p> <p>1987-08-10</p> <p>A corrosive and erosive resistant heat <span class="hlt">exchanger</span> which recovers heat from a contaminated heat stream. The heat <span class="hlt">exchanger</span> utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat <span class="hlt">exchanger</span> surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat <span class="hlt">exchanger</span> wall. Heat from the heat stream is transferred by radiation to the heat <span class="hlt">exchanger</span> wall. Heat is removed from the outer heat <span class="hlt">exchanger</span> wall by a heat recovery medium. 3 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1373831','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1373831"><span id="translatedtitle">A comparative study of the potentiating effect of caffeine and poly-D-lysine on chromosome damage <span class="hlt">induced</span> by X-rays in plant cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mateos, S; Panneerselvam, N; Mateos, J C; Cortés, F</p> <p>1992-04-01</p> <p>X-Ray-<span class="hlt">induced</span> chromosomal aberrations (CA) were potentiated by post-treatments in G2 with either caffeine (caff) or poly-D-lysine (PDL) in root-tip cells of Allium cepa. The enhancement of the yield of CA was concomitant with an increase in the frequency of mitosis. Our results seem to support the idea of a direct relationship between radiation-<span class="hlt">induced</span> G2 delay and repair of chromosome damage. Here we report on similarities between caffeine and PDL in both decreasing G2 delay and enhancing <span class="hlt">chromatid</span> aberration yield. The possible molecular mechanism(s) of action responsible for the cytogenetic effects observed are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/106681','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/106681"><span id="translatedtitle">Phosphonic acid based <span class="hlt">exchange</span> resins</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.</p> <p>1995-09-12</p> <p>An ion <span class="hlt">exchange</span> resin is described for extracting metal ions from a liquid waste stream. An ion <span class="hlt">exchange</span> resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870061','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870061"><span id="translatedtitle">Phosphonic acid based <span class="hlt">exchange</span> resins</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato</p> <p>1995-01-01</p> <p>An ion <span class="hlt">exchange</span> resin for extracting metal ions from a liquid waste stream. An ion <span class="hlt">exchange</span> resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2311049','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2311049"><span id="translatedtitle">Vancouver's needle <span class="hlt">exchange</span> program.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bardsley, J; Turvey, J; Blatherwick, J</p> <p>1990-01-01</p> <p>To stem the spread of HIV among intravenous drug users, and between them and their sexual partners and offspring, Vancouver initiated a multifaceted "ways and means" needle <span class="hlt">exchange</span> program in March of 1989. As of the end of October, over 2,600 users have registered. The needle <span class="hlt">exchange</span> rate has increased steadily, reaching a peak of 98% in November. Increases have also been noted in the number of regular users, and requests for referral to addition, medical, social and HIV-related services. Outreach services, especially using a van, have expanded program availability. Success in terms of clientele response is accredited primarily to the nonjudgemental, nonintrusive approach. The main problems have been the lack of addiction treatment services, financial and personnel constraints created by the large enrollment, and difficulties with Federal/Provincial funding. Funding for evaluation has been requested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17249714','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17249714"><span id="translatedtitle">Serial replica <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hagen, Morten; Kim, Byungchan; Liu, Pu; Friesner, Richard A; Berne, B J</p> <p>2007-02-15</p> <p>Parallel tempering (or the replica <span class="hlt">exchange</span> method (REM)) is a powerful method for speeding up the sampling of conformational states of systems with rough energy landscapes, like proteins, where stable conformational states can be separated by large energy barriers. The usual implementation of the REM is performed on local computer clusters (or parallel processors) where the different replicas must be run synchronously. Here, we present serial replica <span class="hlt">exchange</span> (SREM), a method that is equivalent to the standard REM in terms of efficiency yet runs asynchronously on a distributed network of computers. A second advantage is the method's greatly enhanced fault tolerance, which enables the study of biological systems on worldwide distributed computing environments, such as Folding@Home. For proof of concept, we apply the SREM to a single alanine dipeptide molecule in explicit water. We show that the SREM reproduces the thermodynamic and structural properties determined by the REM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2742604','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2742604"><span id="translatedtitle">Serial Replica <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hagen, Morten; Kim, Byungchan; Liu, Pu; Friesner, Richard A.; Berne, B. J.</p> <p>2009-01-01</p> <p>Parallel tempering (or the replica <span class="hlt">exchange</span> method (REM)) is a powerful method for speeding up the sampling of conformational states of systems with rough energy landscapes, like proteins, where stable conformational states can be separated by large energy barriers. The usual implementation of the REM is performed on local computer clusters (or parallel processors) where the different replicas must be run synchronously. Here, we present serial replica <span class="hlt">exchange</span> (SREM), a method that is equivalent to the standard REM in terms of efficiency yet runs asynchronously on a distributed network of computers. A second advantage is the method’s greatly enhanced fault tolerance, which enables the study of biological systems on worldwide distributed computing environments, such as Folding@Home.1 For proof of concept, we apply the SREM to a single alanine dipeptide molecule in explicit water. We show that the SREM reproduces the thermodynamic and structural properties determined by the REM. PMID:17249714</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24977319','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24977319"><span id="translatedtitle">4-nitroquinoline-1-oxide-<span class="hlt">induced</span> mutagen sensitivity and risk of cutaneous melanoma: a case-control analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Li-E; Li, Chunying; Xiong, Ping; Gershenwald, Jeffrey E; Prieto, Victor G; Duvic, Madeleine; Lee, Jeffrey E; Grimm, Elizabeth A; Hsu, Tao C; Wei, Qingyi</p> <p>2016-04-01</p> <p>Mutagen sensitivity assay, which measures the enhanced cellular response to DNA damage <span class="hlt">induced</span> in vitro by mutagens/carcinogens, has been used in the study of cancer susceptibility. 4-Nitroquinoline-1-oxide (4-NQO), an ultraviolet (UV) radiation-mimetic chemical, can produce chromosomal breaks in mammalian cells and <span class="hlt">induce</span> cancer. Given the potential role of 4-NQO as the experimental mutagen substituting for UV as the etiological carcinogen of cutaneous melanoma (CM), we tested the hypothesis that cellular sensitivity to 4-NQO is associated with the risk of developing CM in a case-control study of 133 patients with primary CM and 176 cancer-free controls. Short-term blood cultures were treated with 4-NQO at a final concentration of 10 μmol/l for 24 h and scored <span class="hlt">chromatid</span> breaks in 50 well-spread metaphases. Multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals. We found that the log-transformed frequency of <span class="hlt">chromatid</span> breaks was significantly higher in 133 patients than in 176 controls (P=0.004) and was associated with an increased risk for CM (adjusted odds ratio=1.78, 95% confidence interval: 1.12-2.84) after adjustment for age and sex. Moreover, as the <span class="hlt">chromatid</span> break values increased, the risk for CM increased in a dose-dependent manner (P(trend)=0.003). Further analysis explored a multiplicative interaction between the sensitivity to 4-NQO and a family history of skin cancer (P(interaction)=0.004) on the risk of CM. Therefore, our findings suggest that sensitivity to 4-NQO may be a risk factor for the risk of CM, which is more sensitive than UV-<span class="hlt">induced</span> chromotid breaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948741','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948741"><span id="translatedtitle">4-Nitroquinoline-1-oxide-<span class="hlt">induced</span> mutagen sensitivity and risk of cutaneous melanoma: a case–control analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Li-E; Li, Chunying; Xiong, Ping; Gershenwald, Jeffrey E.; Prieto, Victor G.; Duvic, Madeleine; Lee, Jeffrey E.; Grimm, Elizabeth A.; Hsu, T.C.; Wei, Qingyi</p> <p>2016-01-01</p> <p>Mutagen sensitivity assay, which measures the enhanced cellular response to DNA damage <span class="hlt">induced</span> in vitro by mutagens/carcinogens, has been used in the study of cancer susceptibility. 4-Nitroquinoline-1-oxide (4-NQO), an ultraviolet (UV) radiation-mimetic chemical, can produce chromosomal breaks in mammalian cells and <span class="hlt">induce</span> cancer. Given the potential role of 4-NQO as the experimental mutagen substituting for UV as the etiological carcinogen of cutaneous melanoma (CM), we tested the hypothesis that cellular sensitivity to 4-NQO is associated with the risk of developing CM in a case–control study of 133 patients with primary CM and 176 cancer-free controls. Short-term blood cultures were treated with 4-NQO at a final concentration of 10 µmol/l for 24 h and scored <span class="hlt">chromatid</span> breaks in 50 well-spread metaphases. Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals. We found that the log-transformed frequency of <span class="hlt">chromatid</span> breaks was significantly higher in 133 patients than in 176 controls (P = 0.004) and was associated with an increased risk for CM (adjusted odds ratio = 1.78, 95% confidence interval: 1.12–2.84) after adjustment for age and sex. Moreover, as the <span class="hlt">chromatid</span> break values increased, the risk for CM increased in a dose-dependent manner (Ptrend = 0.003). Further analysis explored a multiplicative interaction between the sensitivity to 4-NQO and a family history of skin cancer (Pinteraction = 0.004) on the risk of CM. Therefore, our findings suggest that sensitivity to 4-NQO may be a risk factor for the risk of CM, which is more sensitive than UV-<span class="hlt">induced</span> chromosome breaks. PMID:24977319</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/913578','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/913578"><span id="translatedtitle">Thermoelectric heat <span class="hlt">exchange</span> element</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Callas, James J.; Taher, Mahmoud A.</p> <p>2007-08-14</p> <p>A thermoelectric heat <span class="hlt">exchange</span> module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1174441','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1174441"><span id="translatedtitle">Heat <span class="hlt">exchange</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Degtiarenko, Pavel V.</p> <p>2003-08-12</p> <p>A heat <span class="hlt">exchange</span> apparatus comprising a coolant conduit or heat sink having attached to its surface a first radial array of spaced-apart parallel plate fins or needles and a second radial array of spaced-apart parallel plate fins or needles thermally coupled to a body to be cooled and meshed with, but not contacting the first radial array of spaced-apart parallel plate fins or needles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7204436','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7204436"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> tube mounts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wolowodiuk, W.; Anelli, J.; Dawson, B.E.</p> <p>1974-01-01</p> <p>A heat <span class="hlt">exchanger</span> in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26791986','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26791986"><span id="translatedtitle">Hydrogen <span class="hlt">Exchange</span> Mass Spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mayne, Leland</p> <p>2016-01-01</p> <p>Hydrogen <span class="hlt">exchange</span> (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2987866','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2987866"><span id="translatedtitle">The <span class="hlt">exchangeability</span> of shape</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2010-01-01</p> <p>Background Landmark based geometric morphometrics (GM) allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data <span class="hlt">exchange</span>, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species. Results We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of <span class="hlt">exchangeability</span> of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species. Conclusions To preserve both <span class="hlt">exchangeability</span> of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes. PMID:20964872</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16606037','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16606037"><span id="translatedtitle"><span class="hlt">Exchange</span> bias training effect in coupled all ferromagnetic bilayer structures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Binek, Ch; Polisetty, S; He, Xi; Berger, A</p> <p>2006-02-17</p> <p><span class="hlt">Exchange</span> coupled bilayers of soft and hard ferromagnetic thin films show remarkable analogies to conventional antiferromagnetic/ferromagnetic <span class="hlt">exchange</span> bias heterostructures. Not only do all these ferromagnetic bilayers exhibit a tunable <span class="hlt">exchange</span> bias effect, they also show a distinct training behavior upon cycling the soft layer through consecutive hysteresis loops. In contrast with conventional <span class="hlt">exchange</span> bias systems, such all ferromagnetic bilayer structures allow the observation of training <span class="hlt">induced</span> changes in the bias-setting hardmagnetic layer by means of simple magnetometry. Our experiments show unambiguously that the <span class="hlt">exchange</span> bias training effect is driven by deviations from equilibrium in the pinning layer. A comparison of our experimental data with predictions from a theory based upon triggered relaxation phenomena shows excellent agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Scandinavian+AND+social+AND+model&pg=3&id=EJ455196','ERIC'); return false;" href="http://eric.ed.gov/?q=Scandinavian+AND+social+AND+model&pg=3&id=EJ455196"><span id="translatedtitle">Social Skills as <span class="hlt">Exchange</span> Resources.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sletta, Olav</p> <p>1992-01-01</p> <p>A conceptualization of social skills as resources in social <span class="hlt">exchange</span> is offered, and a social <span class="hlt">exchange</span> theoretical framework is applied to educational research. In a social <span class="hlt">exchange</span> framework, the contribution of the peer group to the social exclusion of an individual would not be ignored. (SLD)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21523794','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21523794"><span id="translatedtitle">Broken barriers: human-<span class="hlt">induced</span> changes to gene flow and introgression in animals: an examination of the ways in which humans increase genetic <span class="hlt">exchange</span> among populations and species and the consequences for biodiversity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Crispo, Erika; Moore, Jean-Sébastien; Lee-Yaw, Julie A; Gray, Suzanne M; Haller, Benjamin C</p> <p>2011-07-01</p> <p>We identify two processes by which humans increase genetic <span class="hlt">exchange</span> among groups of individuals: by affecting the distribution of groups and dispersal patterns across a landscape, and by affecting interbreeding among sympatric or parapatric groups. Each of these processes might then have two different effects on biodiversity: changes in the number of taxa through merging or splitting of groups, and the extinction/extirpation of taxa through effects on fitness. We review the various ways in which humans are affecting genetic <span class="hlt">exchange</span>, and highlight the difficulties in predicting the impacts on biodiversity. Gene flow and hybridization are crucially important evolutionary forces influencing biodiversity. Humans alter natural patterns of genetic <span class="hlt">exchange</span> in myriad ways, and these anthropogenic effects are likely to influence the genetic integrity of populations and species. We argue that taking a gene-centric view towards conservation will help resolve issues pertaining to conservation and management. Editor's suggested further reading in BioEssays A systemic view of biodiversity and its conservation: Processes, interrelationships, and human culture Abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005IJMPC..16..607H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005IJMPC..16..607H"><span id="translatedtitle">The Dynamics of Multilateral <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hausken, Kjell; Moxnes, John F.</p> <p></p> <p>The article formulates a dynamic mathematical model where arbitrarily many players produce, consume, <span class="hlt">exchange</span>, loan, and deposit arbitrarily many goods over time to maximize utility. Consuming goods constitutes a benefit, and producing, exporting, and loaning away goods constitute a cost. Utilities are benefits minus costs, which depend on the <span class="hlt">exchange</span> ratios and bargaining functions. Three-way <span class="hlt">exchange</span> occurs when one player acquires, through <span class="hlt">exchange</span>, one good from another player with the sole purpose of using this good to <span class="hlt">exchange</span> against the desired good from a third player. Such a triple handshake is not merely a set of double handshakes since the player assigns no interest to the first good in his benefit function. Cognitive and organization costs increase dramatically for higher order <span class="hlt">exchanges</span>. An <span class="hlt">exchange</span> theory accounting for media of <span class="hlt">exchange</span> follows from simple generalization of two-way <span class="hlt">exchange</span>. The examples of r-way <span class="hlt">exchange</span> are the triangle trade between Africa, the USA, and England in the 17th and 18th centuries, the hypothetical hypercycle involving RNAs as players and enzymes as goods, and reaction-diffusion processes. The emergence of <span class="hlt">exchange</span>, and the role of trading agents are discussed. We simulate an example where two-way <span class="hlt">exchange</span> gives zero production and zero utility, while three-way <span class="hlt">exchange</span> causes considerable production and positive utility. Maximum utility for each player is reached when <span class="hlt">exchanges</span> of the same order as the number of players in society are allowed. The article merges micro theory and macro theory within the social, natural, and physical sciences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27557685','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27557685"><span id="translatedtitle">Generation and Analysis of Transposon Ac/Ds-<span class="hlt">Induced</span> Chromosomal Rearrangements in Rice Plants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xuan, Yuan Hu; Peterson, Thomas; Han, Chang-Deok</p> <p>2016-01-01</p> <p>Closely-located transposable elements (TEs) have been known to <span class="hlt">induce</span> chromosomal breakage and rearrangements via alternative transposition. To study genome rearrangements in rice, an Ac/Ds system has been employed. This system comprises an immobile Ac element expressed under the control of CaMV 35S promoter, and a modified Ds element. A starter line carried Ac and a single copy of Ds at the OsRLG5 (Oryza sativa receptor-like gene 5). To enhance the transpositional activity, seed-derived calli were cultured and regenerated into plants. Among 270 lines regenerated from the starter, one line was selected that contained a pair of inversely-oriented Ds elements at the OsRLG5 (Oryza sativa receptor-like gene 5). The selected line was again subjected to tissue culture to obtain a regenerant population. Among 300 regenerated plants, 107 (36 %) contained chromosomal rearrangements including deletions, duplications, and inversions of various sizes. From 34 plants, transposition mechanisms leading to such genomic rearrangements were analyzed. The rearrangements were <span class="hlt">induced</span> by sister <span class="hlt">chromatid</span> transposition (SCT), homologous recombination (HR), and single <span class="hlt">chromatid</span> transposition (SLCT). Among them, 22 events (65 %) were found to be transmitted to the next generation. These results demonstrate a great potential of tissue culture regeneration and the Ac/Ds system in understanding alternative transposition mechanisms and in developing chromosome engineering in plants. PMID:27557685</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27557685','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27557685"><span id="translatedtitle">Generation and Analysis of Transposon Ac/Ds-<span class="hlt">Induced</span> Chromosomal Rearrangements in Rice Plants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xuan, Yuan Hu; Peterson, Thomas; Han, Chang-Deok</p> <p>2016-01-01</p> <p>Closely-located transposable elements (TEs) have been known to <span class="hlt">induce</span> chromosomal breakage and rearrangements via alternative transposition. To study genome rearrangements in rice, an Ac/Ds system has been employed. This system comprises an immobile Ac element expressed under the control of CaMV 35S promoter, and a modified Ds element. A starter line carried Ac and a single copy of Ds at the OsRLG5 (Oryza sativa receptor-like gene 5). To enhance the transpositional activity, seed-derived calli were cultured and regenerated into plants. Among 270 lines regenerated from the starter, one line was selected that contained a pair of inversely-oriented Ds elements at the OsRLG5 (Oryza sativa receptor-like gene 5). The selected line was again subjected to tissue culture to obtain a regenerant population. Among 300 regenerated plants, 107 (36 %) contained chromosomal rearrangements including deletions, duplications, and inversions of various sizes. From 34 plants, transposition mechanisms leading to such genomic rearrangements were analyzed. The rearrangements were <span class="hlt">induced</span> by sister <span class="hlt">chromatid</span> transposition (SCT), homologous recombination (HR), and single <span class="hlt">chromatid</span> transposition (SLCT). Among them, 22 events (65 %) were found to be transmitted to the next generation. These results demonstrate a great potential of tissue culture regeneration and the Ac/Ds system in understanding alternative transposition mechanisms and in developing chromosome engineering in plants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993STIN...9413730F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993STIN...9413730F"><span id="translatedtitle">High flux heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flynn, Edward M.; Mackowski, Michael J.</p> <p>1993-01-01</p> <p>This interim report documents the results of the first two phases of a four-phase program to develop a high flux heat <span class="hlt">exchanger</span> for cooling future high performance aircraft electronics. Phase 1 defines future needs for high flux heat removal in advanced military electronics systems. The results are sorted by broad application categories: (1) commercial digital systems, (2) military data processors, (3) power processors, and (4) radar and optical systems. For applications expected to be fielded in five to ten years, the outlook is for steady state flux levels of 30-50 W/sq cm for digital processors and several hundred W/sq cm for power control applications. In Phase 1, a trade study was conducted on emerging cooling technologies which could remove a steady state chip heat flux of 100 W/sq cm while holding chip junction temperature to 90 C. Constraints imposed on heat <span class="hlt">exchanger</span> design, in order to reflect operation in a fighter aircraft environment, included a practical lower limit on coolant supply temperature, the preference for a nontoxic, nonflammable, and nonfreezing coolant, the need to minimize weight and volume, and operation in an accelerating environment. The trade study recommended the Compact High Intensity Cooler (CHIC) for design, fabrication, and test in the final two phases of this program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15104921','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15104921"><span id="translatedtitle">Atlantic Telehealth Knowledge <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dwyer, Patricia; Hagerman, Valerie; Ingram, Chris-Anne; MacFarlane, Ron; McCourt, Sherry</p> <p>2004-01-01</p> <p>Atlantic Canada has some of the earliest, most comprehensive, well-established networks, and innovative applications for telehealth in the country. The region offers a range of models for telehealth, in terms of management structure, coordination, funding, equipment, utilization, and telehealth applications. Collectively, this diversity, experience, and wealth of knowledge can significantly contribute to the development of a knowledge base for excellence in telehealth services. There is no formal process in place for the sharing of information amongst the provinces. Information sharing primarily occurs informally through professional contacts and participation in telehealth organizations. A core group of organizations partnered to develop a process for knowledge <span class="hlt">exchange</span> to occur. This type of collaborative approach is favored in Atlantic Canada, given the region's economy and available resources. The Atlantic Telehealth Knowledge <span class="hlt">Exchange</span> (ATKE) project centred on the development of a collaborative structure, information sharing and dissemination, development of a knowledge repository and sustainability. The project is viewed as a first step in assisting telehealth stakeholders with sharing knowledge about telehealth in Atlantic Canada. Significant progress has been made throughout the project in increasing the profile of telehealth in Atlantic Canada. The research process has captured and synthesized baseline information on telehealth, and fostered collaboration amongst telehealth providers who might otherwise have never come together. It has also brought critical awareness to the discussion tables of governments and key committees regarding the value of telehealth in sustaining our health system, and has motivated decision makers to take action to integrate telehealth into e-health discussions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863636','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863636"><span id="translatedtitle">Heat <span class="hlt">exchanger</span>-accumulator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ecker, Amir L.</p> <p>1980-01-01</p> <p>What is disclosed is a heat <span class="hlt">exchanger</span>-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat <span class="hlt">exchange</span> fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040173044&hterms=mammary+gland&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528mammary%2Bgland%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040173044&hterms=mammary+gland&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528mammary%2Bgland%2529"><span id="translatedtitle">Radiation-<span class="hlt">induced</span> chromosomal instability in BALB/c and C57BL/6 mice: the difference is as clear as black and white</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ponnaiya, B.; Cornforth, M. N.; Ullrich, R. L.</p> <p>1997-01-01</p> <p>Genomic instability has been proposed to be the earliest step in radiation-<span class="hlt">induced</span> tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-<span class="hlt">induced</span> instability. BALB/c white mice are considerably more sensitive to radiation-<span class="hlt">induced</span> mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the "delayed" appearance of chromosomal aberrations after exposure to 137Cs gamma radiation, as a measure of radiation-<span class="hlt">induced</span> genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of <span class="hlt">chromatid</span>-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of <span class="hlt">chromatid</span>-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-<span class="hlt">induced</span> instability in the process of tumorigenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26520375','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26520375"><span id="translatedtitle">Low concentrations of caffeine <span class="hlt">induce</span> asymmetric cell division as observed in vitro by means of the CBMN-assay and iFISH.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hatzi, Vasiliki I; Karakosta, Maria; Barszczewska, Katarzyna; Karachristou, Ioanna; Pantelias, Gabriel; Terzoudi, Georgia I</p> <p>2015-11-01</p> <p>The dual role of caffeine as a chromosomal damage <span class="hlt">inducer</span> and G2/M-checkpoint abrogator is well known but it is observed mainly at relatively high concentrations. At low concentrations, caffeine enhances the cytogenetic effects of several carcinogens and its intake during pregnancy has been recently reported to cause adverse birth outcomes. Interestingly, a threshold below which this association is not apparent was not identified. Since chromosomal abnormalities and aneuploidy are the major genetic etiologies of spontaneous abortions and adverse birth outcomes, we re-evaluate here the effects of caffeine at the cytogenetic level and propose a model for the mechanisms involved. Our hypothesis is that low caffeine concentrations affect DNA replication and cause chromosomal aberrations and asymmetric cell divisions not easily detected at metaphase since damaged cells are delayed during their G2/M-phase transition and the low caffeine concentrations cannot abrogate the G2-checkpoint. To test this hypothesis, caffeine-<span class="hlt">induced</span> <span class="hlt">chromatid</span> breaks and micronuclei in peripheral blood lymphocytes (PBLs) were evaluated in vitro after low caffeine concentration exposures, followed by a short treatment with 4mM of caffeine to abrogate the G2-checkpoint. The results show a statistically significant increase in <span class="hlt">chromatid</span> breaks at caffeine concentrations ≥1mM. When caffeine was applied for G2/M-checkpoint abrogation, a statistically significant increase in <span class="hlt">chromatid</span> breaks, compared to an active checkpoint, was only observed at 4mM of caffeine. The potential of low concentrations to <span class="hlt">induce</span> asymmetric cell divisions was tested by applying a methodology combining the cytochalasin-B mediated cytokinesis-block micronucleus assay (CBMN) with interphase FISH (iFISH), using selected centromeric probes. Interestingly, low caffeine concentrations <span class="hlt">induce</span> a dose dependent aneuploidy through asymmetric cell divisions, which are caused by misalignment of chromosomes through a mechanism</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26520375','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26520375"><span id="translatedtitle">Low concentrations of caffeine <span class="hlt">induce</span> asymmetric cell division as observed in vitro by means of the CBMN-assay and iFISH.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hatzi, Vasiliki I; Karakosta, Maria; Barszczewska, Katarzyna; Karachristou, Ioanna; Pantelias, Gabriel; Terzoudi, Georgia I</p> <p>2015-11-01</p> <p>The dual role of caffeine as a chromosomal damage <span class="hlt">inducer</span> and G2/M-checkpoint abrogator is well known but it is observed mainly at relatively high concentrations. At low concentrations, caffeine enhances the cytogenetic effects of several carcinogens and its intake during pregnancy has been recently reported to cause adverse birth outcomes. Interestingly, a threshold below which this association is not apparent was not identified. Since chromosomal abnormalities and aneuploidy are the major genetic etiologies of spontaneous abortions and adverse birth outcomes, we re-evaluate here the effects of caffeine at the cytogenetic level and propose a model for the mechanisms involved. Our hypothesis is that low caffeine concentrations affect DNA replication and cause chromosomal aberrations and asymmetric cell divisions not easily detected at metaphase since damaged cells are delayed during their G2/M-phase transition and the low caffeine concentrations cannot abrogate the G2-checkpoint. To test this hypothesis, caffeine-<span class="hlt">induced</span> <span class="hlt">chromatid</span> breaks and micronuclei in peripheral blood lymphocytes (PBLs) were evaluated in vitro after low caffeine concentration exposures, followed by a short treatment with 4mM of caffeine to abrogate the G2-checkpoint. The results show a statistically significant increase in <span class="hlt">chromatid</span> breaks at caffeine concentrations ≥1mM. When caffeine was applied for G2/M-checkpoint abrogation, a statistically significant increase in <span class="hlt">chromatid</span> breaks, compared to an active checkpoint, was only observed at 4mM of caffeine. The potential of low concentrations to <span class="hlt">induce</span> asymmetric cell divisions was tested by applying a methodology combining the cytochalasin-B mediated cytokinesis-block micronucleus assay (CBMN) with interphase FISH (iFISH), using selected centromeric probes. Interestingly, low caffeine concentrations <span class="hlt">induce</span> a dose dependent aneuploidy through asymmetric cell divisions, which are caused by misalignment of chromosomes through a mechanism</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24204306','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24204306"><span id="translatedtitle">Genome-wide high-resolution mapping of UV-<span class="hlt">induced</span> mitotic recombination events in Saccharomyces cerevisiae.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yin, Yi; Petes, Thomas D</p> <p>2013-10-01</p> <p>In the yeast Saccharomyces cerevisiae and most other eukaryotes, mitotic recombination is important for the repair of double-stranded DNA breaks (DSBs). Mitotic recombination between homologous chromosomes can result in loss of heterozygosity (LOH). In this study, LOH events <span class="hlt">induced</span> by ultraviolet (UV) light are mapped throughout the genome to a resolution of about 1 kb using single-nucleotide polymorphism (SNP) microarrays. UV doses that have little effect on the viability of diploid cells stimulate crossovers more than 1000-fold in wild-type cells. In addition, UV stimulates recombination in G1-synchronized cells about 10-fold more efficiently than in G2-synchronized cells. Importantly, at high doses of UV, most conversion events reflect the repair of two sister <span class="hlt">chromatids</span> that are broken at approximately the same position whereas at low doses, most conversion events reflect the repair of a single broken <span class="hlt">chromatid</span>. Genome-wide mapping of about 380 unselected crossovers, break-<span class="hlt">induced</span> replication (BIR) events, and gene conversions shows that UV-<span class="hlt">induced</span> recombination events occur throughout the genome without pronounced hotspots, although the ribosomal RNA gene cluster has a significantly lower frequency of crossovers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1306719','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1306719"><span id="translatedtitle">International Cell <span class="hlt">Exchange</span>: 1992.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lau, M; Terasaki, P I; Park, M S</p> <p>1992-01-01</p> <p>1. This is a review of 1992 typing of 40 cells for Class I antigens and 18 cultured cell lines for Class II antigens through the International Cell <span class="hlt">Exchange</span>. Serological typings were compared with DNA typing reports for Class II specificities. Presently, 290 laboratories participate in the monthly Class I <span class="hlt">exchange</span>. Class II results were received monthly from 166 serology laboratories and from 36 DNA laboratories. 2. In 1992, 11 of the 16 A-locus antigens attained 95% or greater average detection. Nine of the 27 B-locus antigens showed 95% or better mean agreement levels. Antigens such as B46 and B70 continued to show improvement in detection in a 5-year period. 3. We compared discrepancy rates of 7 A-locus and 8 B-locus antigens typed 3 times or more. The rates for the B-locus specificities, especially for percentages of false negatives (ie, how often the antigen assignment was missed), continued to be greater than those for the A-locus antigens. Nevertheless, the discrepancy rates of B35 and B70 decreased dramatically during the last 5 years. 4. We showed the number of laboratories with the total of false negatives and false positives. Nine laboratories achieved perfect records (0 false negatives and false positives) for all analyzed antigens in 1992. 5. Results of retyping of 3 donors over several years were shown to indicate improved antigen detection. 6. Recently recognized HLA-specificities, such as A2403 and B5102, were shown as cell variants studied in previous cell <span class="hlt">exchanges</span>. Variants of B15, B16, and B40 families were presented, as well as several new A-locus antigens. 7. The low and high rates, in addition to the average detection levels, were indicated for a total of 27 (18 DR and 9 DQ) Class II specificities by serology and by DNA typings. Eight of the 15 DR/DRB1 specificities attained 90% or better average agreement by both serology and DNA. Three of the 9 DQ antigens achieved 90% or better average detection by both methods. 8. Confirmation by DNA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26747520','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26747520"><span id="translatedtitle">Cross-Shelf <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brink, K H</p> <p>2016-01-01</p> <p>Cross-shelf <span class="hlt">exchange</span> dominates the pathways and rates by which nutrients, biota, and materials on the continental shelf are delivered and removed. This follows because cross-shelf gradients of most properties are usually far greater than those in the alongshore direction. The resulting transports are limited by Earth's rotation, which inhibits flow from crossing isobaths. Thus, cross-shelf flows are generally weak compared with alongshore flows, and this leads to interesting observational issues. Cross-shelf flows are enabled by turbulent mixing processes, nonlinear processes (such as momentum advection), and time dependence. Thus, there is a wide range of possible effects that can allow these critical transports, and different natural settings are often governed by different combinations of processes. This review discusses examples of representative transport mechanisms and explores possible observational and theoretical paths to future progress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910041720&hterms=thermohaline+circulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528thermohaline%2Bcirculation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910041720&hterms=thermohaline+circulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528thermohaline%2Bcirculation%2529"><span id="translatedtitle">South Atlantic interbasin <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rintoul, Stephen Rich</p> <p>1991-01-01</p> <p>The <span class="hlt">exchange</span> of mass and heat between the South Atlantic and the neighboring ocean basins was estimated using hydrographic data and inverse methods, in order to gain information on the links between the deep-water formation processes occurring within the Atlantic and the global thermohaline circulation. Results demonstrate that the global thermohaline cell associated with the formation and export of North Atlantic deep water (NADW) is closed primarily by a 'cold water path' in which deep water leaving the Atlantic ultimately returns as intermediate water entering the basin through Drake Passage. This conclusion conflicts with the suggestion by Gordon (1986) that the global thermohaline circulation associated with the formation of NADW is closed primarily by a 'warm water path', in which the export of NADW is compensated by an inflow of warm Indian Ocean thermocline water south of Africa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100023388','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100023388"><span id="translatedtitle">Hybrid Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tu, Jianping Gene; Shih, Wei</p> <p>2010-01-01</p> <p>A hybrid light-weight heat <span class="hlt">exchanger</span> concept has been developed that uses high-conductivity carbon-carbon (C-C) composites as the heat-transfer fins and uses conventional high-temperature metals, such as Inconel, nickel, and titanium as the parting sheets to meet leakage and structural requirements. In order to maximize thermal conductivity, the majority of carbon fiber is aligned in the fin direction resulting in 300 W/m.K or higher conductivity in the fin directions. As a result of this fiber orientation, the coefficient of thermal expansion (CTE) of the C-C composite in both non-fiber directions matches well with the CTE of various high-temperature metal alloys. This allows the joining of fins and parting sheets by using high-temperature braze alloys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7547576','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7547576"><span id="translatedtitle">International Cell <span class="hlt">Exchange</span>, 1994.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lau, M; Terasaki, P I; Park, M S</p> <p>1994-01-01</p> <p>1. We summarize typings of 40 cells for Class I antigens and 20 cultured cell lines for Class II antigens through the International Cell <span class="hlt">Exchange</span> in 1994. Serologic Class II typings were compared with DNA typings for the same 20 cells. Two hundred eighty-one laboratories participated in the monthly Class I Serum <span class="hlt">Exchange</span>. One hundred nineteen serology laboratories and 74 DNA laboratories reported Class II specificities on a monthly basis. 2. The average detection levels, as well as the high detection levels, were determined for 16 A-locus and 27 B-locus antigens. Mean detection rates of 95% or greater average detection were obtained for 12 A-locus and 10 B-locus antigens. Lower than 80% agreement was calculated for one A-locus antigen (A74) and 7 B-locus (B46, B48, B61, B67, B73, B75, B77) antigens. 3. We compared discrepancy rates of 10 A-locus and 7 B-locus antigens typed 3 times or more. The false-negative discrepancy rates, i.e. how often the antigen was missed, were greater for more of the B-locus specificities than for the A-locus antigens. B62, having the highest false-positive rate, tended to be overassigned. The discrepancy rates, especially the false-negative rate, for B70 were shown to decrease over a 7-year period. 4. In 1994, 8 laboratories attained records of total no misses for all analyzed antigens. Twelve laboratories had final records of only one discrepancy, and 5 laboratories had impressive perfect records (zero false negatives and false positives) for their yearly antigen reports. 5. Retyping of 12 Class I and 8 Class II reference cells showed improved detection of antigens. Results of a donor typed 4 times over 11 years demonstrated marked improvement, nearly doubling for A33, B38, and B75. Two cells first typed in 1991, then retyped in 1994, showed improved detection for Class II splits by serology and DNA typing. 6. We updated the list of sequenced Class I <span class="hlt">Exchange</span> cells. Seven new cells were added as well as confirmatory sequence data for A</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="https://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="https://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Information" height="31" width="53"></a> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center footer-content-right"> <a href="http://www.osti.gov/nle"><img src="https://www.osti.gov/images/footerimages/NLElogo31.png" alt="National Library of Energy" height="31" width="79"></a> <a href="http://www.science.gov"><img src="https://www.osti.gov/images/footerimages/scigov77.png" alt="science.gov" height="31" width="98"></a> <a href="http://worldwidescience.org"><img src="https://www.osti.gov/images/footerimages/wws82.png" alt="WorldWideScience.org" height="31" width="90"></a> </div> </div> </div> </div> </div> <p><br></p> </div><!-- container --> </body> </html>