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Sample records for chromatid exchange induced

  1. Tumor promoter induces sister chromatid exchanges: relevance to mechanisms of carcinogenesis.

    PubMed Central

    Kinsella, A R; Radman, M

    1978-01-01

    12-O-Tetradecanoylphorbol 13-acetate (TPA), a powerful tumor promoter, is shown to induce sister chromatid exchanges (SCEs), whereas the nonpromoting derivative 4-O-methyl-TPA does not. Inhibitors of tumor promotion--antipain, leupeptin, and fluocinolone acetonide--inhibit formation of such TPA-induced SCEs. TPA is a unique agent in its induction of SCEs in the absence of DNA damage, chromosome aberrations, mutagenesis, or significant toxicity. Because TPA is known to induce several gene functions, we speculate that it might also induce enzymes involved in genetic recombination. Thus, the irreversible step in tumor promotion might be the result of an aberrant mitotic segregation event leading to the expression of carcinogen/mutagen-induced recessive genetic or epigenetic chromosomal changes. Images PMID:282631

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

    PubMed

    Morales-Ramírez, P; Vallarino-Kelly, T; Rodríguez-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.

  3. Sister chromatid exchange induced by etheno-ATP derivatives in vitro.

    PubMed

    Conner, M K; Modzelewski, R A; Kawatani, N

    1989-07-15

    Genotoxic activities of a series of commercially purchased 1,N6-ethenoadenosine (epsilon-Ado) and epsilon-deoxyadenosine (epsilon-dAdo) derivatives were assessed using the sister chromatid exchange (SCE) assay in murine spleen lymphocytes in vitro. Of the epsilon-Ado adducts evaluated for SCE induction epsilon-ATP and epsilon-dATP were highly active (5x baseline) SCE inducers over a concentration range of 50-150 microM. Moderate SCE-inducing activities were seen with epsilon-dAdo, epsilon-A, and epsilon-AMP. epsilon-A was of particular interest in that spleen lymphocytes from a single mouse were highly sensitive to SCE (greater than 50 SCE/cell at 75 microM). epsilon-Ado was weakly effective and epsilon-ADP and epsilon-dAMP did not produce significantly elevated SCEs. Cocanavalin A-stimulated T-lymphocytes and lipopolysaccharide-stimulated B-lymphocytes exhibited comparable SCE responses to epsilon-A, epsilon-AMP, and epsilon-dATP. However, B-lymphocytes were considerably less sensitive than T-lymphocytes to epsilon-dAdo and epsilon-ATP. Evaluation of the purities of specific epsilon-Ado derivatives, as performed by high-performance liquid chromatography and thin layer chromatography, failed to detect potential contaminants as cytogenetically active agents. However, a difference (about threefold) in cytogenetic activities of two lot numbers of epsilon-ATP paralleled the difference in UV absorbance of quivalent concentrations (mg/ml), prepared according to the manufacturers stated purity. Any impurities likely to be present were consistent with inactive nonchromophoric compounds such as buffer salts. Because of the direct genotoxic activity of epsilon-A in intact mammalian cells, we suggest that intracellular adenylate pools, including the prominent ubiquitous nucleotide ATP, are non-DNA targets for epsilon-modification by active metabolites and the resulting epsilon-adducts are likely to be active moieties in SCE induction and in neoplastic transformation produced

  4. Effect of pretreatment with cysteamine on gamma-radiation-induced sister chromatid exchanges in mouse bone marrow cells in vivo

    SciTech Connect

    Mendiola-Cruz, M.T.; Morales-Ramirez, P.

    1989-04-01

    The effect of pretreatment with cysteamine on gamma-radiation-induced sister chromatid exchanges (SCEs) and on the mitotic index and average generation time was determined. Groups of mice were treated in one of the following regimens: (1) irradiated, (2) treated with cysteamine and irradiated, (3) treated with cysteamine only, or (4) left untreated. Intraperitoneal administration of cysteamine preceding gamma-radiation exposure protected against SCE induction. However, radioprotection was not reflected by change in the mitotic index or in the average generation time. The results suggest that, under the experimental conditions of this study, the SCEs are caused by free radicals produced by gamma radiation, but not the additional damage indices measured.

  5. 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)

  6. 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.

  7. Enhancement of benzo(a)pyrene-induced sister chromatid exchanges in lymphocytes from cigarette smokers occupationally exposed to asbestos

    SciTech Connect

    Kelsey, K.T.; Christiani, D.C.; Little, J.B.

    1986-08-01

    The frequencies of base-line and benzo(a)pyrene ((BP) CAS 50-38-8)-induced sister chromatid exchanges (SCE) were measured in peripheral blood lymphocytes from 22 male asbestos-exposed workers and 10 nonexposed workers of comparable age. A clear association between cigarette smoking and asbestos exposure in the sensitivity of lymphocytes to BP was observed. Among asbestos-exposed workers, lymphocytes from those who smoked cigarettes were significantly more susceptible to the induction of SCE by in vitro exposure to BP (P = .01) than were lymphocytes from nonsmokers. Active smoking elevated the base-line SCE frequency in both asbestos-exposed and nonexposed workers (P = .001), and an interaction between smoking and asbestos in the production of base-line SCE was suggested (P = .07). Asbestos exposure alone was not associated with an enhanced susceptibility to the induction of SCE by BP or with an elevation of base-line SCE. Increased age was associated with an increase in SCE inducibility by BP (P = .01), and a history of smoking was marginally associated with SCE inducibility by BP (P = .07). These findings support the hypothesis that an increased susceptibility of asbestos-exposed individuals to polyaromatic hydrocarbon-induced cancer results from an enhanced sensitivity to the induction of genetic damage rather than to an asbestos-induced differential cellular metabolic capacity.

  8. Both cross-links and monoadducts induced in DNA by psoralens can lead to sister chromatid exchange formation

    SciTech Connect

    Cortes, F. Facultad de Biologia, Sevilla ); Morgan, W.F.; Varcarcel, E.R.; Cleaver, J.E.; Wolff, S. )

    1991-09-01

    The relative importance of DNA-DNA cross-links and bulky monoadducts in sister chromatid exchange (SCE) formation was investigated in three human fibroblast cell lines with different repair capabilities. These cell lines included normal cells, which can repair both classes of lesion; xeroderma pigmentosum (XP) cells, which cannot repair either psoralen-induced cross-links or monoadducts; and an XP revertant that repairs only cross-links and not monoadducts. SCEs were induced by two psoralen derivatives. After activation with long-wave ultraviolet light, HMT produces cross-links and monoadducts in DNA, whereas 5-MIP produces only monoadducts. In normal human cells both psoralens induced SCEs, but if cells were allowed to repair for 18 h before bromodeoxyuridine (BrdUrd) was added for SCE analysis, the SCE frequency was significantly reduced. XP cells showed an SCE frequency that remained high regardless of whether SCEs were analyzed immediately after psoralen exposure of 18 h later. In the XP revertant that repairs only cross-links, both psoralens induced a high yield of SCEs when BrdUrd was added immediately after psoralen treatment. These observations indicate that both cross-links and monoadducts are lesions in DNA that can lead to SCE formation.

  9. Ability of 13 chemical agents used in dental practice to induce sister-chromatid exchanges in Syrian hamster embryo cells.

    PubMed

    Miyachi, Takashi; Tsutsui, Takeki

    2005-09-01

    To evaluate the genotoxic potential of 13 chemical agents used in dental practice, the abilities of these agents to induce sister-chromatid exchanges (SCEs) were examined using Syrian hamster embryo (SHE) cells. Statistically significant increases in the frequencies of SCEs were observed in SHE cells treated with all seven of the chemical agents used as endodontic medicaments: p-chlorophenol, m-cresol, formaldehyde, guaiacol, hydrogen peroxide, p-phenolsulfonic acid, and sodium hypochlorite (P < 0.01; Student t test). Assessment of two chemical agents that are applied to the oral mucosa as antiseptics showed that SCEs were induced by iodine (P < 0.01), but not by chlorhexidine. Of three chemical agents that are used as dyes for disclosing dental plaque, erythrosine B had no effect on SCE induction, while acid fuchsin and basic fuchsin increased the SCE frequencies in SHE cells (P < 0.01). Glutaraldehyde, which is used as a disinfectant for dental instruments and impressions, also induced SCEs (P < 0.01). Because SCE assays are used as a sensitive indicator for evaluating genetic toxicity of chemicals, the chemical agents that had a positive response in the present study are potentially genotoxic to mammalian cells.

  10. 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.

  11. Ultraviolet-induced sister chromatid exchanges in V-79 cells with normal and BrdUrd-substituted DNA and the influence of intercalating substances and cysteine

    SciTech Connect

    Speit, G.; Mehnert, K.; Wolf, M.; Vogel, W.

    1982-06-01

    The influence of intercalating substances (proflavine, ethidium bromide) and of an SH compound (L-cysteine) on uv-induced sister chromatid exchanges (SCEs) was investigated in V-79 cells with normal and BrdUrd-substituted DNA. The results are discussed in relation to the primary damages leading to SCE induction produced by uv irradiation. The data indicate that neither the pyrimidine dimers nor DNA single-strand breaks are the primary cause of SCE induction, and that the damages leading to SCEs by uv irradiation differ from those which cause chromosome aberrations.

  12. Evidence for Msh2 haploinsufficiency in mice revealed by MNU-induced sister-chromatid exchange analysis

    PubMed Central

    Bouffler, S D; Hofland, N; Cox, R; Fodde, R

    2000-01-01

    The role of Msh2 in chromosome stability has been investigated in a targeted mouse model for HNPCC Msh2Δ7N. Chromosome aberration frequencies were similar in bone marrow of Msh2+/+Msh2+/–and Msh2–/–mice and no differential effects of in vivo X-irradiation were noted. By contrast, the induction of sister-chromatid exchanges (SCEs) by methyl nitrosourea (MNU) was reduced in Msh2–/–and Msh2+/–cells to ~20% and ~45% wild-type levels respectively indicating a phenotypic effect of haploinsufficiency of the mouse Msh2 gene. © 2000 CancerResearch Campaign PMID:11044352

  13. Sister chromatid exchange, DNA repair, and single-gene mutation

    SciTech Connect

    Carrano, A.V.; Thompson, L.H.

    1982-01-01

    Sister chromatid exchange (SCE) has been studied in cultured mammalian cells with regard to the nature of the inducing lesion, mutation induction, and factors that modify the observed frequency following mutagen exposure, SCEs can be induced by a wide spectrum of DNA lesions and, for nine agents examined, the frequency of induced SCE is linearly related to induced single-gene mutation. Further, a deficiency in DNA repair may alter the expression of both SCE and mutation in a qualitatively similar manner. The frequency of SCE induced by mitomycin-C is suppressed in heterochromatic relative to euchromatin and, in nondividing lymphocytes, the lesions leading to the formation of SCEs may persist for several months.

  14. 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

  15. Promutagen activation of triazine herbicides metribuzin and ametryn through Vicia faba metabolism inducing sister chromatid exchanges in human lymphocytes in vitro and in V. faba root tip meristems.

    PubMed

    Flores-Maya, Saúl; Gómez-Arroyo, Sandra; Calderón-Segura, María Elena; Villalobos-Pietrini, Rafael; Waliszewski, Stefan M; de la Cruz, Leticia Gómez

    2005-03-01

    The aim of our study was the induction of sister chromatid exchanges (SCE) in human lymphocytes in vitro and in root tip meristems of Vicia faba to evaluate the genotoxic effects of metribuzin and ametryn. Direct treatments of these herbicides on human lymphocytes in vitro applied 24 h after the beginning of culture did not induce SCE; however, they showed a cytotoxic effect in the cultures expressed as cellular death. On the contrary, when extracts of V. faba roots, treated for 4 h with metribuzin and ametryn (in vivo activation), were added to the lymphocyte cultures, SCEs were significantly induced with an asymptotic response. Negative responses appeared with the in vitro assays, in which metribuzin and ametryn were added directly to the 48 h lymphocyte cultures for 4 h. Nevertheless, in treatments in which the S10 metabolic mix was added, the SCE frequencies were significantly different to the control, although a concentration-response relationship was only observed with metribuzin. The results showed that both herbicides needed the V. faba metabolism to produce SCE in human lymphocyte cultures. Metribuzin and ametryn applied to V. faba root tip meristems for 4 h increased SCE frequency significantly, and a concentration-response relationship was observed with both herbicides.

  16. Effect of cholic acid on the colonic sister chromatid exchange frequency induced by 1,2-dimethylhydrazine in C57BL/6 mice

    SciTech Connect

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

    1991-01-01

    Induction of sister chromatid exchangers (SCE) has been used as evidence of genotoxicity of test compounds administered both in vitro and in vivo. The authors have previously reported their efforts to measure SCE frequencies in colonic tissue in vivo. While the method described did produce chromosome preparations suitable for SCE analysis, the yield of differentiated well-spread metaphase chromosomes was sometimes relatively low, making scoring more time consuming than for determination of SCE frequencies in most cell types. They speculated that if the mitotic index of the tissue could be increased, the yield of metaphases suitable for scoring SCEs would also be increased, reducing the time required to obtain results. Inclusion of cholic acid in the diet of experimental animals is known to produce marked increases in the mitotic activity of colonic tissue, thus providing a possible means by which to effect the desired improvements. The authors report here on the effect of dietary cholic acid on the SCE frequencies induced in murine colonic tissue by the colon carcinogen 1,2-dimethylhydrazine (DMH).

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) 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 of... is considered not to induce rearrangements of DNA segments in this system. (iii) Both biological...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) 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 of... is considered not to induce rearrangements of DNA segments in this system. (iii) Both biological...

  19. Chromosome breakage and sister chromatid exchange analysis in computer operators

    SciTech Connect

    Butler, M.G.; Yost, J.; Jenkins, B.B.

    1987-01-01

    Chromosome breakage analysis with Mitomycin C (MMC) and sister chromatid exchanges (SCE) were obtained on 10 computer operators with computer exposure for a minimum of 3 hours per day for 4 years and 10 control subjects matched for age and personal lifestyle. No difference was found between the two groups in the total number of chromatid and chromosome aberrations in cells grown at 48 and/or 96 hours in Mitomycin C (20 or 50 ng/ml-final concentration). The average number of SCE per cell in approximately 30 cells from each person was 6.4 +/- 1.1 (mean +/- standard deviation) for the computer operators and 9.2 +/- 1.6 for the controls. This difference was significant (p < .001). The replicative index was significantly higher (p < .01) in computer operators than in control subjects. The number of SCE appeared not to be influenced by the years of computer exposure. Additional studies with larger sample sizes will be needed to identify if significant differences exist in cell kinetics and sister chromatid exchanges in individuals employed as computer operators.

  20. 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

  1. A Manyfold Increase in Sister Chromatid Exchanges in Bloom's Syndrome Lymphocytes

    PubMed Central

    Chaganti, R. S. K.; Schonberg, S.; German, James

    1974-01-01

    Dividing cells from persons with Bloom's syndrome, an autosomal recessive disorder of growth, exhibit increased numbers of chromatid breaks and rearrangements. A highly characteristic feature of the chromosome instability in this syndrome is the tendency for exchanges to occur between chromatids of homologous chromosomes at homologous sites. In the present experiments, a cytogenetic technique by which the sister chromatids of a metaphase chromosome are stained differentially has been used to demonstrate a striking and possibly specific, but hitherto unrecognized, increase in the frequency with which sister chromatids also exchange segments. The cells were grown in bromodeoxyuridine and stained with 33258 Hoechst and Giemsa. Whereas phytohemagglutinin-stimulated lymphocytes from normal controls had a mean of 6.9 sister chromatid exchanges per metaphase (range 1-14), those from persons with Bloom's syndrome had a mean of 89.0 (range 45-162). Normal frequencies of sister chromatid exchanges were found in cells heterozygous for the Bloom's syndrome gene, and also in cells either homozygous or heterozygous for the genes of the Louis-Bar (ataxia telangiectasia) syndrome and Fanconi's anemia, two other rare disorders characterized by chromosome instability. In a differentially stained chromatid interchange configuration discovered during the study, it was possible to determine the new distribution of both sister and non-sister-but-homologous chromatids that had resulted from numerous exchanges. By following shifts in the pattern of staining from chromatid to chromatid, visual evidence was obtained that the quadriradial configurations long recognized as characteristic of Bloom's syndrome represent exchanges between homologous chromosomes, apparently at homologous points. We postulate that the increase in the frequency of exchanges between nonsister-but-homologous chromatids and those between sister chromatids in Bloom's syndrome represents aspects of one and the same

  2. Sister chromatid exchange in Polish White improved goats (Capra hircus).

    PubMed

    Wójcik, Ewa; Smalec, Elzbieta

    2012-01-01

    The study was aimed at evaluating the frequency of spontaneous sister chromatid exchange in Polish White Improved goats (Capra hircus). The mean number of SCEs/cell was 2.73 +/- 1.84. The effect of sex and age on SCE incidence was also investigated. No statistically significant differences in the number of SCEs/cell were observed between the males and females. On the other hand, age was found to significantly influence SCE frequency. A lower SCE frequency was observed in younger goats. A positive correlation between chromosome length and SCE number was identified. The longer the chromosome, the more exchanges occurred. The highest number of SCEs was observed in the interstitial region, the lowest in the distal area.

  3. Evaluation and application of an in vivo mouse assay for chemically induced sister chromatid exchanges and chromosome aberrations: Annual progress report, September 30, 1986-September 29, 1987

    SciTech Connect

    McFee, A.F.

    1987-10-15

    This reporting period constituted the first year of our renewed contract which calls for an increased number of personnel and an increase in the number of chemicals to be tested per year. The majority of our efforts were utilized in the training of personnel and the testing of submitted chemicals. During the year we received from the NIEHS repository coded aliquots of 16 test compounds. Each of these has been evaluated to determine the most desirable vehicle in which to administer them to test animals. The testing of chemicals for SCE induction requires the treatment of 25 mice with varying levels of the test compound and control materials and the scoring of 25 second-division metaphases from each animal. An extended time protocol was adopted which utilizes treatment to sacrifice times of 36 hours for chromosome aberrations and 42 hours for sister chromatid exchange evaluation. The micronucleus assay performed on polychromatic erythrocytes of the bone marrow offers some potential advantages as a cytogenetic assay for clastogenic chemicals. We have initiated a limited study comparing SCE induction by several chemicals which had previously been shown to be positive for SCE's. Where possible, we are administering the same doses of the compounds in suspension or solutions in the three carriers. Chemicals with a variety of solubility characteristics (and all being SCE positive) will be utilized to provide data on the possible influence of the solvent/carrier on mutagenic potency. 5 refs.

  4. Increased levels of sister chromatid exchanges in military aircraft pilots.

    PubMed

    Silva, M J; Carothers, A; Castelo Branco, N; Dias, A; Boavida, M G

    1999-04-26

    Sister chromatid exchanges (SCEs) were scored in lymphocytes of nine high-performance pilots of alphajet aircrafts and of ten control individuals from the same air base. Statistical analysis of the mean SCE count per cell in the total number of cells analyzed as well as in those having 12 or more SCEs (high-frequency cells, HFCs) revealed a significant difference between pilots and controls, after adjusting for the effect of smoking. Analysis of the cell cycle kinetic data (replication and mitotic indices) revealed no significant differences either between pilots and controls or between smokers and nonsmokers. Previously, we reported an increase in the SCE levels in workers of the aeronautical industry exposed to noise and whole-body vibration. The present results corroborate those findings and indicate that noise and whole-body vibration may cause genotoxic effects in man.

  5. No significant increase in chromosome aberrations and sister chromatid exchanges in cultured human lymphocytes treated with spiramycin.

    PubMed

    Rencüzoğullari, Eyyüp; Ila, Hasan Basri; Topaktaş, Mehmet; Kayraldiz, Ahmet; Budak, Songül; Arslan, Mehmet

    2002-01-01

    In this study, the chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) were investigated in human lymphocytes treated with spiramycin antibiotic (trade name, rovamycin). Spiramycin did not induce the CAs and SCEs, and also did not decrease the mitotic index (MI). However, spiramycin decreased the replication index (RI) only at 48 h treatment times.

  6. SiO2 Nanoparticule-induced size-dependent genotoxicity - an in vitro study using sister chromatid exchange, micronucleus and comet assay.

    PubMed

    Battal, Dilek; Çelik, Ayla; Güler, Gizem; Aktaş, Ayça; Yildirimcan, Saadet; Ocakoglu, Kasim; Çömelekoǧlu, Ülkü

    2015-04-01

    Fine particles with a characteristic size smaller than 100 nm (i.e. nanoparticlesspread out in nowadays life. Silicon or Si, is one of the most abundant chemical elements found on the Earth. Its oxide forms, such as silicate (SiO4) and silicon dioxide, also known as silica (SiO2), are the main constituents of sand and quartz contributing to 90% of the Earth's crust. In this work, three genotoxicity systems "sister chromatid exchange, cytokinesis block micronucleus test and single cell gel electrophoresis (comet) assay" were employed to provide further insight into the cytotoxic and mutagenic/genotoxic potential of SiO2 nanoparticules (particle size 6 nm, 20 nm, 50 nm) in cultured peripheral blood lymphocytes as in vitro. It was observed that there is a significant decrease in Mitotic index (MI), Cytokinesis block proliferation index (CBPI), proliferation index (PRI) values expressed as Cell Kinetic parameters compared with negative control (p < 0.05). There is a statistically significant difference between negative control culture and culture exposed to SiO2 (6 nm, 20 nm, 50 nm) (p < 0.01, p < 0.01, p < 0.05, respectively). It is found that SiO2 nanoparticles at different size (6, 20, 50 nm) progressively increased the SCE frequency and DNA damage on the basis the AU values compared with negative control (p < 0.05). Results showed that the genotoxic/mutagenic and cytotoxic effects of SiO2 nanoparticules is dependent to particule size.

  7. Sister chromatid exchange data and Gram-Charlier series.

    PubMed

    Bowman, K O; Eddings, W; Kastenbaum, M A; Shenton, L R

    1998-07-17

    Bowman et al. [K.O. Bowman, M.A. Kastenbaum, L.R. Shenton, Fitting multi-parameter distributions to SCE data, Mutat. Res., 358 (1996) 15-24.] showed how discrete Pearson and discrete Johnson translation-system distributions may be fitted to sister chromatid exchange (SCE) data presented by Bender et al. [M.A. Bender, R.J. Pearston, 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.]. When their performances were measured by the chi-squared test of goodness of fit, these distributions proved to be only moderately better alternatives to the poorly fitting Poisson, binomial, and negative binomial distributions. In this paper, we extend our search for better characterizations of the SCE data by calling upon the Gram-Charlier type B approximation of the negative binomial distribution. We introduce an innovative extension of methods described in a little-known paper by Aitken and Gonin [A.C. Aitken, H.T. Gonin, On fourfold sampling with and without replacement, Proc. R. Soc. Edinburgh, 55 (1934) 114-125.], and show how this leads to fits of the SCE data that, in general, are within acceptable levels of probability. Moreover, we show how a theorem by Cramér [H. Cramér, Mathematical Methods of Statistics, Princeton Univ. Press, 1946.], relating to the scale factor m2/m'1 and its asymptotic distribution, may be used to discriminate between smokers and nonsmokers of the same gender.

  8. Increase of sister chromatid exchanges and perturbations of cell division kinetics in human lymphocytes by benzene metabolites

    SciTech Connect

    Morimoto, K.; Wolff, S.

    1980-04-01

    Benzene, which has been associated with human cancers, is metabolized to produce several major metabolites that could be responsible for the biological effects. Tests have now been carried out on human lymphocytes in culture to determine if benzene or its metabolites, phenol, catechol, and hydroquinone, induce cytogenetic changes and affect the cell cycle. The results indicate that benzene itself does not induce sister chromatid exchanges or affect cell cycle kinetics over a wide range of doses. Catechol is a potent compound that induces sister chromatid exchanges and delays cell division very readily. Hydroquinone is also potent, but less so than catechol. Thus, the formation of catechol and hydroquinone is the most likely cause of benzene toxicity.

  9. Bromodeoxyuridine does not contribute to sister chromatid exchange events in normal or Bloom syndrome cells

    PubMed Central

    van Wietmarschen, Niek; Lansdorp, Peter M.

    2016-01-01

    Sister chromatid exchanges (SCEs) are considered sensitive indicators of genome instability. Detection of SCEs typically requires cells to incorporate bromodeoxyuridine (BrdU) during two rounds of DNA synthesis. Previous studies have suggested that SCEs are induced by DNA replication over BrdU-substituted DNA and that BrdU incorporation alone could be responsible for the high number of SCE events observed in cells from patients with Bloom syndrome (BS), a rare genetic disorder characterized by marked genome instability and high SCE frequency. Here we show using Strand-seq, a single cell DNA template strand sequencing technique, that the presence of variable BrdU concentrations in the cell culture medium and in DNA template strands has no effect on SCE frequency in either normal or BS cells. We conclude that BrdU does not induce SCEs and that SCEs detected in either normal or BS cells reflect DNA repair events that occur spontaneously. PMID:27185886

  10. Sister chromatid exchanges are mediated by homologous recombination in vertebrate cells.

    PubMed

    Sonoda, E; Sasaki, M S; Morrison, C; Yamaguchi-Iwai, Y; Takata, M; Takeda, S

    1999-07-01

    Sister chromatid exchange (SCE) frequency is a commonly used index of chromosomal stability in response to environmental or genetic mutagens. However, the mechanism generating cytologically detectable SCEs and, therefore, their prognostic value for chromosomal stability in mitotic cells remain unclear. We examined the role of the highly conserved homologous recombination (HR) pathway in SCE by measuring SCE levels in HR-defective vertebrate cells. Spontaneous and mitomycin C-induced SCE levels were significantly reduced for chicken DT40 B cells lacking the key HR genes RAD51 and RAD54 but not for nonhomologous DNA end-joining (NHEJ)-defective KU70(-/-) cells. As measured by targeted integration efficiency, reconstitution of HR activity by expression of a human RAD51 transgene restored SCE levels to normal, confirming that HR is the mechanism responsible for SCE. Our findings show that HR uses the nascent sister chromatid to repair potentially lethal DNA lesions accompanying replication, which might explain the lethality or tumorigenic potential associated with defects in HR or HR-associated proteins.

  11. Absence of an ultrasound effect on in vitro lymphocyte sister chromatid exchange

    SciTech Connect

    Brulfert, A.; Ciaravino, V.; Miller, M.W.; Carstensen, E.L.

    1983-01-01

    The frequency of sister chromatid exchanges (SCEs) in human lymphocytes cultured in vitro was not affected by a 30 min exposure to 2.25 MHz focused ultrasound beam (from a clinical diagnostic unit with a pulse repetition rate of 1000 Hz, a 1 ..mu.. sec burst duration, and a 2-200 W/cm/sup 2/ maximum intensity. A 30 sec exposure to CW 1 MHz 2 W/cm/sup 2/ (SP) ultrasound from an experimental device lysed 10-15% of the lymphocytes; there was no increase in SCEs in the survivors relative to unexposed controls. Treatment of lymphocytes with 0.033 ..mu..g/ml mitomycin-C, a known SCE inducer, increased the frequency of SCEs about 4 times above control levels.

  12. Induction of sister chromatid exchanges in traffic policemen exposed to vehicular exhaust.

    PubMed

    Sreedevi, Varre; Hemaprasad, Mundluru; Sandhyadevi, Gundimeda; Reddy, Penagaluru Pardhanandana

    2006-07-14

    In urban areas there is an explosive growth of population and the number of automobiles. The ever-increasing vehicular traffic density is posing continued threat to the ambient air quality. Traffic policemen as a group of workers are exposed occupationally to the pollutants from vehicular exhaust. Sister chromatid exchanges (SCEs) as a biomarker of the pollutant's effect, were analyzed in peripheral blood lymphocytes of 85 traffic policemen and 60 control subjects. There was a significant increase in the mean SCEs+/-S.D./cell in the exposed group (9.31+/-5.29) when compared to the controls (4.18+/-1.85). Thus the present study concludes that vehicular exhaust might induce cytogenetic damage in traffic police. Further, the more pronounced frequency of SCEs observed in the smoking traffic policemen than in the non-smoking group suggests the joint effect of smoking and vehicular exhaust.

  13. 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.

  14. Sister chromatid exchange induced by short-lived monoadducts produced by the bifunctional agents mitomycin C and 8-methoxypsoralen. [CHO cells

    SciTech Connect

    Linnainmaa, K.; Wolff, S.

    1982-01-01

    To see if DNA crosslinks are involved in the induction of sister chromated exchange (SCE), Chinese hamster ovary cells were exposed to two bifunctional alkylating agents,mitomycin C and 8-methoxypsoralen, and their monofunctional derivatives, decarbamoyl mitomycin C and angelicin. The data indicates that monoadducts, rather than crosslinks, are responsible for SCE formation. Furthermore, all agents but angelicin produced short-lived lesions that led to SCEs in the first period of DNA replication after treatment (twin SCEs). In contrast, angelicin, like methyl methanesulfonate and N-acetoxyacetylaminofluorene, produced lesions that lasted more than one cycle, indicating that several different types of DNA lesions are capable of SCE induction.

  15. Lymphocyte proliferation kinetics and sister-chromatid exchanges in individuals treated with metronidazole.

    PubMed

    Elizondo, G; Montero, R; Herrera, J E; Hong, E; Ostrosky-Wegman, P

    1994-03-01

    Metronidazole, an effective agent for the treatment of protozoan infections, is frequently used in developing countries. However, the employment of this drug has been questioned in view of its mutagenicity in bacteria and carcinogenicity in mice. A genotoxic study was carried out in which cellular proliferation kinetics and the frequency of sister-chromatid exchanges were determined in human peripheral blood lymphocytes from 12 individuals treated with therapeutic doses of metronidazole. No effect was observed on mitotic index with the treatment, although a significant increase was found in three individuals after treatment. No increase of sister-chromatid exchanges was detected. The rate of lymphocyte proliferation kinetics showed an increase after the metronidazole treatment in all patients, indicating a possible immunostimulatory action.

  16. Frequency of sister chromatid exchange in peripheral lymphocytes of male pesticide applicators

    SciTech Connect

    Rupa, D.S. ); Reddy, P.P. ); Sreemannarayana, K. ); Reddi, O.S. )

    1991-01-01

    In the present study 61 male pesticide applicators who worked in cotton fields and regularly sprayed pesticides such as DDT, BHC, endosulfan, malathion, methyl parathion, phosphamidon, dimethoate, monocrotophos, quinalphos fenvelrate, and cypermethrin were analyzed for sister chromatid exchanges, mitotic index, and cell cycle kinetics in peripheral lymphocytes. Subjects who handled pesticides were non-smokers and teetotalers and the data were compared with the matched control group. Statistical analysis revealed that the frequency of sister chromatid exchanges was significantly higher among the pesticide applicators at all the durations of exposure when compared to controls. Subjects exposed to pesticides also showed cell cycle delay and decrease in mitotic index when compared to the control group.

  17. Sister chromatid exchange induction and cell cycle inhibition by aniline and its metabolites in human fibroblasts

    SciTech Connect

    Wilmer, J.L.; Kligerman, A.D.; Erexson, G.L.

    1981-01-01

    Sister chromatid exchange (SCE) and cell cycle analyses in human fibroblasts were used to ascertain the relative genotoxicity and cytotoxicity of aniline and its metabolites. Significant increases (P0.05) in SCE frequencies were found with aniline HCl, o-aminophenol, N-phenylhydroxylamine, and trimethymelamine (TEM). On an SCE/mmole basis at the highest concentrations examined, o-aminophenol was 270 times more potent than aniline in inducing SCE, whereas TEM was about 390 times more potent than o-aminophenol. Furthermore, fibroblasts treated with o-aminophenol responded in a dose-dependent fashion and exhibited a 2-fold increase in SCE frequency. N-phenylhydroxylamine induced a less clear-cut, dose related increase in SCE frequency with a 1.4-fold elevation. Only marginal increases in SCE were observed with aniline at the highest doses. Using these data, we propose that aniline may exert its turmorigenic potential in rats through the production of both genotoxic and cytotoxic metabolities. (JMT)

  18. 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.

  19. Mutagenicity and induction of sister chromatid exchange by optically active enantiomers of secondary butyl methanesulfonate

    SciTech Connect

    Ball, J.C.; Salmeen, I.T. ); Morris, S.M. )

    1989-01-01

    This report describes experiments in which a chiral alkyl methanesulfonate was used to investigate possible mechanisms by which alkylating agents cause their mutagenic, cytotoxic, and clastogenic effects. Optically active enantiomers and the racemic mixtures of 2-butyl methanesulfonate (2-BMS) were cytotoxic and mutagenic in Chinese hamster V79 cells and in AS52 cells and mutagenic in Salmonella typhimurium strains TA100 and TA1535. Within the experimental uncertainties, the cytotoxicity and mutagenicity curves were the same for the R and S enantiomers and for the racemic mixture. The 2-BMS isomers were cytotoxic and induced sister chromatid exchanges (SCE) in CHO-K{sub 1}-BH{sub 4} cells. The cytotoxicity curve was similar to that observed with V79 and AS52 cells. The results can be interpreted two ways. The first interpretation is that 2-BMS reacts via a carbocation, and the second interpretation involves an S{sub N}2 reaction of 2-BMS with DNA. The latter interpretation suggests that the mechanisms of mutagenesis, cytotoxicity, or the induction of SCE cannot distinguish between small (four-carbon) optically active DNA adducts. The authors favor the second interpretation because of solvolysis experiments showing the complete inversion of configuration of optically active 2-octyl methanesulfonate. While they assume that optically active 2-BMS will react using the same mechanism as chiral 2-OMS, they cannot exclude the possibility that 2-BMS reacts via a carbonation intermediate.

  20. 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.

  1. Timeless Maintains Genomic Stability and Suppresses Sister Chromatid Exchange during Unperturbed DNA Replication.

    PubMed

    Urtishak, Karen A; Smith, Kevin D; Chanoux, Rebecca A; Greenberg, Roger A; Johnson, F Brad; Brown, Eric J

    2009-03-27

    Genome integrity is maintained during DNA replication by coordination of various replisome-regulated processes. Although it is known that Timeless (Tim) is a replisome component that participates in replication checkpoint responses to genotoxic stress, its importance for genome maintenance during normal DNA synthesis has not been reported. Here we demonstrate that Tim reduction leads to genomic instability during unperturbed DNA replication, culminating in increased chromatid breaks and translocations (triradials, quadriradials, and fusions). Tim deficiency led to increased H2AX phosphorylation and Rad51 and Rad52 foci formation selectively during DNA synthesis and caused a 3-4-fold increase in sister chromatid exchange. The sister chromatid exchange events stimulated by Tim reduction were largely mediated via a Brca2/Rad51-dependent mechanism and were additively increased by deletion of the Blm helicase. Therefore, Tim deficiency leads to an increased reliance on homologous recombination for proper continuation of DNA synthesis. Together, these results indicate a pivotal role for Tim in maintaining genome stability throughout normal DNA replication.

  2. Sister chromatid exchange analysis in workers exposed to noise and vibration.

    PubMed

    Silva, M J; Carothers, A; Branco, N C; Dias, A; Boavida, M G

    1996-07-10

    Workers chronically exposed to whole-body vibration and noise are known to develop pathophysiological and psychological disturbances. The frequencies of sister chromatid exchanges (SCEs) and of cells with high frequencies of SCEs (HFCs) were analyzed in lymphocytes of 50 workers occupationally exposed to vibration and noise and of 34 controls. The exposed group included: individuals operating hand-vibrating tools (group 1), 'test-cell operators' (group 2) and 'run-up' operators (group 3) from an air base and helicopter pilots (group 4). The statistical analysis of the mean SCE count per cell was carried out by multiple regression analysis, comparing various predictor variables: exposure group, duration of exposure, age and cigarette consumption. Only cigarette consumption and exposure group were found to be significantly correlated with the mean SCE frequency. After allowing for the effects of smoking, the analysis indicates that: (1) there was no significant difference between group 1 and controls (p > 0.05); (2) the differences between group 2 and group 0, group 3 and group 0 and group 4 and group 0 were all highly significant (p < 0.001); (3) there was no significant difference between groups 2 and 3 (p > 0.05), nor between groups 2 and 3 combined and group 4 (p > 0.05); (4) exposure groups 2, 3 and 4 combined, had a significantly elevated mean SCE frequency compared to the control group (p < 0.0001). Statistical analysis of the proportion of HFCs was consistent with these results. Our data suggest that chronic exposure to whole-body vibration and noise may lead to an increase in the level of SCEs in man. The observed effects may not reflect a direct action of these physical agents on DNA. Alternative explanations may include some of the whole-body vibration and noise-induced or stress-induced pathophysiological alterations which may indirectly induce SCE formation.

  3. Induction by inorganic metal salts of sister chromatid exchanges and chromosome aberrations in human and Syrian hamster cell strains

    SciTech Connect

    Larramendy, M.L.; Popescu, N.C.; DiPaolo, J.A.

    1981-01-01

    Sister chromatid exchange (SCE) and chromosome aberration induction were determined for several inorganic metal salts. Arsenic, nickel, and beryllium salts at concentrations effective in causing transformation of Syrian hamster cells (HEC) induced SCE and chromosome aberrations of HEC and human lymphocytes, whereas sodium tungstate, a non-transforming chemical, neither induced SCE nor chromosome aberrations. Normal human and hamster cells exhibited equal sensitivity to SCE induction; nontoxic concentrations of sodium arsenite, beryllium sulfate, and nickel sulfate caused an increase of 8-10 SCE/cell over control values. Sodium arsenite, a trivalent arsenic, and sodium arsenate, a pentavalent arsenic, produced increases in SCE but the former was effective at lower concentrations. Both arsenic salts were less efficient in inducing SCE in human whole blood than in purified lymphocyte cultures. Sodium arsenite, sodium arsenate, nickel sulfate, and beryllium sulfate also caused damage consisting primarily of chromatid type of aberrations. In HEC, with doses most effective in SCE induction , all four metals produced aberrations in 16-21% of cells. In human lymphocytes, 34 and 30% of the cells had chromosome damage after sodium arsenite and sodium arsenate, respectively, whereas beryllium sulfate or nickel sulfate caused damage in about 10% of the cells. The induction of SCE and chromosomal aberrations by metals reemphasizes the sensitivity of cytological assays and their importance for detecting genetic damage caused by carcinogens.

  4. Further characterization of the genotoxicity of formaldehyde in vitro by the sister chromatid exchange test and co-cultivation experiments.

    PubMed

    Neuss, Simone; Speit, Günter

    2008-09-01

    The induction of sister chromatid exchanges (SCE) was used to further characterize the genotoxic action of formaldehyde (FA) on cultured mammalian cells. FA induced SCE in V79 Chinese hamster cells and A549 human lung cells in a concentration-related manner. Addition of 5-bromodeoxyuridine (BrdUrd) for the differentiation of sister chromatids to visualize SCE 4 h after the FA treatment led to a clearly reduced induction of SCE in agreement with the repair kinetics of FA-induced DNA-protein cross-links. When A549 cells were treated with FA for 1 h and then co-cultivated with V79 cells in the presence of BrdUrd, a clear induction of SCE was measured in V79 cells. When the same experiment was performed including washing and change of medium after the FA treatment, no induction of SCE was measured in V79 cells. These results indicate that reactive FA remains in the cell culture medium for a longer time period despite the high reactivity of FA with macromolecules. However, FA that has entered a cell is not released and does not damage other cells. Possible implications for the mutagenicity of FA in vivo will be discussed.

  5. 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)

  6. Sister chromatid exchange frequency in human epidermal cells in culture treated with 8-methoxypsoralen and long-wave UV radiation

    SciTech Connect

    West, M.R.; Johansen, M.; Faed, M.J.

    1982-01-01

    The effects of 8-methoxypsoralen with long-wave ultraviolet radiation on the sister chromatid exchange frequency in human epidermal cells in culture was investigated. With a constant amount of radiation the number of exchanges increased in an approximately linear manner with increasing concentrations of 8-methoxypsoralen up to 0.3 micrograms/ml. Above this concentration there were fewer dividing cells and an apparent departure from linearity in the dose-response curve. These results show that 8-methoxypsoralen concentrations equivalent to those found in the serum of patients undergoing photochemotherapy, in conjunction with UVA radiation, cause striking increases in sister chromatid exchange frequency in human epidermal cells in vitro.

  7. Induction of sister-chromatid exchange in human blood lymphocytes by aqueous extract of palmyrah (Borassus flabellifer) flour.

    PubMed

    Kangwanpong, D; Maratana, D; Temcharoen, P

    1989-10-01

    pPalmyrah palm (Borassus flabellifer) is widely consumed by people in certain tropical countries. The incidence of human malignant lymphomas, mutagenicity and toxicity in rats and bacteria encouraged us to study the potency of palmyrah crude aqueous extracts in inducing sister-chromatid exchanges (SCEs) in human blood lymphocytes in vitro. The extracts induced SCEs in a dose-related manner in both females and males. These effects apparently showed no consistency between batches. This result may be due to the intrinsic variation of different donors in their response to the induction of SCEs by palmyrah extracts. SCE frequency was proportional to chromosome length and SCEs at the centromeric region showed no difficulty in being scored. Concerning methods of short-term cytogenetic testing for detecting mutagenic and carcinogenic chemicals, we found that the SCE test was not more sensitive than the classic chromosome-breakage test.

  8. Effect of betel chewing on the frequency of sister chromatid exchanges in pregnant women and women using oral contraceptives.

    PubMed

    Ghosh, P K; Ghosh, R

    1988-06-01

    The incidence of sister chromatid exchange (SCE) was investigated in the lymphocyte chromosomes of betel chewing and non-chewing normal women, pregnant women, and women using oral contraceptives. The frequency of SCE was found to be 7.82 +/- 0.24 and 8.27 +/- 0.27 in non-chewing pregnant women and women using oral contraceptives respectively, which were significantly higher than the mean value of 5.21 +/- 0.18 observed in non-chewing normal women. Betel chewing induced higher SCE in pregnant women and women using oral contraceptives, the frequencies being 11.79 +/- 0.38 and 12.51 +/- 0.44, respectively, which were significantly higher than the SCE frequency of 6.28 +/- 0.21 found in normal betel chewing females.

  9. Sister-chromatid exchange analysis in a rural population of Mexico exposed to pesticides.

    PubMed

    Gómez-Arroyo, S; Noriega-Aldana, N; Osorio, A; Galicia, F; Ling, S; Villalobos-Pietrini, R

    1992-03-01

    Cytogenetic damage was evaluated by means of the analysis of sister-chromatid exchange (SCE) in a rural population of Tlaxcala, Mexico, in occupational contact with pesticides. We studied 170 men, 94 exposed and 76 not exposed. It was shown that SCE followed a normal distribution and Student's t test did not present differences between the two groups (P = 0.4). The frequency of SCE was not correlated with the duration of exposure of the rural workers (r = -0.06), the multiple covariance analysis applied to the data of duration of exposure, tobacco intake and alcohol ingestion demonstrated a lack of statistical significance. In the exposed people we observed no symptoms provoked by these compounds.

  10. 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.

  11. Induction of sister chromatid exchange in the presence of gadolinium-DTPA and its reduction by dimethyl sulfoxide

    SciTech Connect

    Yamazaki, Etsuo; Fukuda, Hozumi; Shibuya, Hitoshi; Matsubara, Sho

    1996-05-01

    The authors investigate the frequency of sister chromatid exchange (SCE) after the addition of gadolinium (Gd)-DTPA to venous blood samples. Venous blood was obtained from nonsmokers. Samples were incubated with Gd-DTPA alone or in combination with mitomycin C, cytarabine, and dimethyl sulfoxide (DMSO), and then evaluated for SCEs. The frequency of SCE increased with the concentration of Gd-DTPA and as each chemotherapeutic agent was added. Sister chromatid exchange frequencies were lower when the blood was treated with a combination of Gd-DTPA and DMSO compared with Gd-DTPA alone. The increase in frequency of SCE seen after the addition of Gd-DTPA was decreased by the addition of DMSO, indicating the production of hydroxyl radicals. The effect likely is dissociation-related. 14 refs., 6 tabs.

  12. Persistence of sister chromatid exchanges and in vitro morphological transformation of Syrian hamster fetal cells by chemical and physical carcinogens

    SciTech Connect

    Popescu, N.C.; Amsbaugh, S.C.; DiPaolo, J.A.

    1985-11-01

    The induction of neoplastic cell transformation is closely associated with DNA alterations which occur shortly after carcinogen exposure. Sister chromatid exchange (SCE) formation is a sensitive indicator of carcinogen-DNA interaction and correlates with the induction of morphological cell transformation. The persistence of lesions generating SCE produced by chemical and physical carcinogens and its relevance to the induction of morphologic transformation was evaluated in coordinated experiments with cultured Syrian hamster fetal cells (HFC). Exponentially growing HFC were exposed for 1 h to benzo(a)pyrene (BP), methyl-methanesulfonate (MMS), cis-platinum (II) diaminedichloride (cis Pt II), N-methyl-N'-nitrosourea (MNU), mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), N-acetoxy-2-fluorenyl-acetamide (AcAAF) or u.v. light irradiated. SCE analysis demonstrates that for a period of 48 h after carcinogen exposure, during which time the cells undergo at least four replicative cycles, DNA damage generating SCE induced by all chemical carcinogens either persisted or was partially removed, whereas u.v.-induced lesions were completely removed. An elevated SCE frequency persisted after two additional cell cycles after treatment with BP, AcAAF or MMC without increased cell lethality as compared to other carcinogens whose lesions were completely eliminated during the same period.

  13. Hypersensitivity to mutation and sister-chromatid-exchange induction in CHO cell mutants defective in incising DNA containing UV lesions

    SciTech Connect

    Thompson, L.H.; Brookman, K.W.; Dillehay, L.E.; Mooney, C.L.; Carrano, A.V.

    1982-01-01

    Five UV-sensitive mutant strains of CHO cells representing different genetic complementation groups were analyzed for their ability to perform the incision step of nucleotide excision repair after UV exposure. The assay utilized inhibitors of DNA synthesis to accumulate the short-lived strand breaks resulting from repair incisions. After 6 J/m/sup 2/, each of the mutants showed < 10% of the incision rate of the parental AA8 cells. After 50 J/m/sup 2/, the rate in AA8 was similar to that at 6 J/m/sup 2/, but the rates in the mutants were significantly higher (approx. 20% of the rate of AA8). Thus by this incision assay the mutants were phenotypically indistinguishable. Each of the mutants were hypersensitive to mutation induction at both the hprt and aprt loci by a factor of 10, and in the one strain tested ouabain resistance was induced sevenfold more efficiently than in AA8 cells. Sister chromatid exchange was also induced with sevenfold increased efficiency in the two mutant strains examined. Thus, here CHO mutants resemble xeroderma pigmentosum cells in terms of their incision defects and their hypersensitivity to DNA damage by UV.

  14. A high rate of telomeric sister chromatid exchange occurs in chronic lymphocytic leukaemia B-cells.

    PubMed

    Medves, Sandrine; Auchter, Morgan; Chambeau, Laetitia; Gazzo, Sophie; Poncet, Delphine; Grangier, Blandine; Verney, Aurélie; Moussay, Etienne; Ammerlaan, Wim; Brisou, Gabriel; Morjani, Hamid; Géli, Vincent; Palissot, Valérie; Berchem, Guy; Salles, Gilles; Wenner, Thomas

    2016-07-01

    Cancer cells protect their telomere ends from erosion through reactivation of telomerase or by using the Alternative Lengthening of Telomere (ALT) mechanism that depends on homologous recombination. Chronic lymphocytic leukaemia (CLL) B cells are characterized by almost no telomerase activity, shelterin deregulation and telomere fusions. To characterize telomeric maintenance mechanisms in B-CLL patients, we measured their telomere length, telomerase expression and the main hallmarks of the ALT activity i.e. C-circle concentration, an extra-chromosomal telomere repeat (ECTR), and the level of telomeric sister chromatid exchange (T-SCE) rate. Patients showed relative homogenous telomere length although almost no TERT transcript and nearly no C-circle were evidenced. Nevertheless, compared with normal B cells, B-CLL cells showed an increase in T-SCE rate that was correlated with a strong down-regulation of the topoisomerase III alpha (TOP3A) expression, involved in the dissolution of Holliday Junctions (HJ), together with an increased expression of SLX1A, SLX4, MUS81 and GEN1, involved in the resolution of HJ. Altogether, our results suggest that the telomere maintenance mechanism of B-CLL cells do not preferentially use telomerase or ALT. Rather, the rupture of the dissolvasome/resolvasome balance may increase telomere shuffling that could homogenize telomere length, slowing telomere erosion in this disease.

  15. Enhanced response to the induction of sister chromatid exchange by gamma radiation in neurofibromatosis

    SciTech Connect

    Hafez, M.; Abd el-Nabi, S.M.; el-Wehedi, G.; Al-Tonbary, Y.

    1986-05-15

    The study included 8 unrelated patients with neurofibromatosis, and 10 unrelated normal and healthy persons as controls. Whole blood samples were divided into plastic T flasks and exposed at room temperature to gamma rays. The radiation dose was 36 rad/minute, and the doses delivered were 0, 75, 150 and 300 rad. The lymphocytes were cultured in (RPMI) 1640 tissue culture medium and autologous serum (20%). Phytohemagglutinin and bromodeoxyuridine (Brdu) (10 microM) were added at initiation of culture and harvesting was done 64 to 68 hours after culture initiation. Slides were coded, differential staining was done, and sister chromatid exchanges (SCEs) and aberrations (gaps, breaks, dicentrics, fragments and minutes) were counted. In the controls no significant increase in frequency of SCE has been found (P greater than 0.5). In the patients, the frequencies significantly increased with the increase of dose of irradiation (P less than 0.001). Furthermore, after irradiation, the incidence of gaps, breaks, and dicentrics were significantly increased in patients compared with controls. Moreover, the incidence increased with the increase in the dose of radiation. The results are discussed with a conclusion that the results add to the indication of a genetic predisposition to develop cancer in neurofibromatosis patients.

  16. 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.

  17. 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

  18. 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.

  19. Sister chromatid exchanges and micronuclei in peripheral lymphocytes of shoe factory workers exposed to solvents.

    PubMed Central

    Pitarque, Marià; Vaglenov, Alexander; Nosko, Maria; Pavlova, Sonya; Petkova, Vera; Hirvonen, Ari; Creus, Amadeu; Norppa, Hannu; Marcos, Ricard

    2002-01-01

    We examined sister chromatid exchanges (SCEs) and micronuclei (MN; cytokinesis-block method) in cultured peripheral lymphocytes from 52 female workers of two shoe factories and from 36 unexposed age- and sex-matched referents. The factory workers showed an elevated level of urinary hippuric acid, a biomarker of toluene exposure, and workplace air contained high concentrations of various organic solvents such as toluene, gasoline, acetone, and (in one of the plants only) ethylacetate and methylenediphenyl diisocyanate. The shoe factory workers showed a statistically significant higher frequency of micronucleated binucleate lymphocytes in comparison with the referents. This finding agreed with three preliminary MN determinations (each comprising 27-32 shoe workers and 16-20 controls) performed in one of the plants 2-5 years earlier. The shoe factory workers also had a lower average level of blood hemoglobin than the referents. In contrast, no difference was found between the groups in SCE analysis. Smokers showed significantly higher mean frequencies of SCEs per cell and high frequency cells (HFC) than nonsmokers. Aging was associated with increased MN rates and reduced cell proliferation. Polymorphism of the glutathione S-transferase M1 gene (GSTM1) did not affect the individual level of SCEs; but in smoking shoe workers an effect of the occupational exposure on the frequency of micronucleated cells could be seen only in GSTM1 null subjects. The low prevalence of the glutathione S-transferase T1 (GSTT1) null genotype precluded the evaluation of the influence of GSTT1 polymorphism. Our results show that the shoe factory workers have experienced genotoxic exposure, which is manifest as an increase in the frequency of MN, but not of SCEs, in peripheral lymphocytes. The exposures responsible for the MN induction could not be identified with certainty, but exposure to benzene in gasoline and methylenediphenyl diisocyanate may explain some of the findings. PMID:11940458

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Sister chromatid exchange analysis in lung and peripheral blood lymphocytes of mice exposed to methyl isocyanate by inhalation

    SciTech Connect

    Kligerman, A.D.; Campbell, J.A.; Erexson, G.L.; Allen, J.W.; Shelby, M.D.

    1987-01-01

    Mice were exposed to 1, 3, or 6 ppm methyl isocyanate (MIC) for 6 hr/day for four consecutive days. Lung cells and peripheral blood lymphocytes (PBLs) were removed and cultured for analysis of sister chromatid exchange (SCE) and cell cycle kinetics. MIC caused a small but significant increase in SCE frequency of cultured lung cells from mice exposed to 1, 3, or 6 ppm MIC. MIC did not significantly increase SCE levels in PBLs of mice exposed to concentrations as high as 6 ppm. In cultured PBLs, MIC had a stimulatory effect on cell cycling rates as measured by the replicative index, and it caused a significant reduction in mononuclear leucocyte counts and the mitotic indices.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. Sister chromatid exchange response of human diploid fibroblasts and Chinese hamster ovary cells to dimethylnitrosamine and benzo(a)pyrene

    SciTech Connect

    Tomkins, D.J.; Kwok, S.E.; Douglas, G.R.; Biggs, D.

    1982-01-01

    In the search for relevant assays for mutagenicity testing, considerable attention has been given to the use of mammalian cells in vitro and the incorporation of metabolic activation in the protocol. Chinese hamster ovary (CHO) cells are commonly chosen as the target cells for cytogenetic tests because of their excellent growth characteristics and long lifespan in culture. However, there may be cellular factors affecting the uptake, metabolism, and repair of damage which are not the same in cell lines. The response of CHO cells and three human diploid fibroblast strains (1MR-90, WI-38, S-3299) to benzo(a)pyrene (BP) and dimethylnitrosamine (DMN) were compared using sister chromatid exchange (SCE) analysis as a measure of genetic damage. For both BP and DMN the human cells and the CHO cells showed dose-response slopes that were significantly different from zero, except CHO cells treated with BP for 1 hr and S-3299 cells treated with DMN. Whereas human and CHO cells showed similar dose-response to BP and the three human cell strains had similar dose-responses to BP and DMN, the dose-response of the human cells to DMN was statistically less significant than that of CHO cells. Reducing the duration of chemical treatment in CHO cells had no effect on the slope of the dose-response curves for BP or DMN. The observed differences between human and CHO cells may reflect differences in the fate of metabolic intermediates of DMN.

  13. 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.

  14. Genotoxicity of thimerosal in cultured human lymphocytes with and without metabolic activation sister chromatid exchange analysis proliferation index and mitotic index.

    PubMed

    Eke, Dilek; Celik, Ayla

    2008-06-01

    Thimerosal is an antiseptic containing 49.5% of ethyl mercury that has been used for years as a preservative in many infant vaccines and in flu vaccines. Thimerosal is an organic mercurial compound used as a preservative in biomedical preparations. In this study, we evaluated the genotoxic effect of thimerosal in cultured human peripheral blood lymphocytes using sister chromatid exchange analysis in culture conditions with and without S9 metabolic activation. This study is the first report investigating the genotoxic effects of thimerosal in cultured human peripheral blood lymphocyte cells using sister chromatid exchange analysis. An analysis of variance test (ANOVA) was performed to evaluate the results. Significant induction of sister chromatid exchanges was seen at concentrations between 0.2 and 0.6 microg/ml of thimerosal compared with negative control. A significant decrease (p<0.001) in mitotic index (MI) and proliferation index (PRI) as well as an increase in SCE frequency (p<0.001) was observed compared with control cultures. Our results indicate the genotoxic and cytotoxic effect of TH in cultured human peripheral blood lymphocytes at tested doses in cultures with/without S9 fraction.

  15. The Walker B motif in avian FANCM is required to limit sister chromatid exchanges but is dispensable for DNA crosslink repair

    PubMed Central

    Rosado, Ivan V.; Niedzwiedz, Wojciech; Alpi, Arno F.; Patel, Ketan J.

    2009-01-01

    FANCM, the most highly conserved component of the Fanconi Anaemia (FA) pathway can resolve recombination intermediates and remodel synthetic replication forks. However, it is not known if these activities are relevant to how this conserved protein activates the FA pathway and promotes DNA crosslink repair. Here we use chicken DT40 cells to systematically dissect the function of the helicase and nuclease domains of FANCM. Our studies reveal that these domains contribute distinct roles in the tolerance of crosslinker, UV light and camptothecin-induced DNA damage. Although the complete helicase domain is critical for crosslink repair, a predicted inactivating mutation of the Walker B box domain has no impact on FA pathway associated functions. However, this mutation does result in elevated sister chromatid exchanges (SCE). Furthermore, our genetic dissection indicates that FANCM functions with the Blm helicase to suppress spontaneous SCE events. Overall our results lead us to reappraise the role of helicase domain associated activities of FANCM with respect to the activation of the FA pathway, crosslink repair and in the resolution of recombination intermediates. PMID:19465393

  16. 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.

  17. Erythrocytes modulate the baseline frequency of sister-chromatid exchanges and the kinetics of lymphocyte division in culture.

    PubMed

    Larramendy, M L; Reigosa, M A; Bianchi, M S

    1990-09-01

    The baseline sister-chromatid exchange (SCE) frequencies of human plasma lymphocyte cultures (PLC), but not pig PLC, were nearly twice as high as those of whole-blood cultures (WBC). Addition of human red blood cells (RBCs) to human PLC decreased the SCE frequency in proportion to the RBC-leukocyte co-incubation interval. When the period of RBC-leukocyte co-incubation was equivalent to the total length of the culture period (72 h), the SCE frequency was similar to that observed in WBC. Shorter co-incubation periods yielded SCE frequencies intermediate between those of PLC and WBC. Regardless of the species, cell proliferation was slower in PLC than in WBC. Experiments where RBCs were added to PLC showed that the time sequence of RBC incorporation also affects the cell-cycle progression of human and pig lymphocytes. When either human or pig RBCs were added immediately after PLC stimulation, the cell-cycle kinetics was similar to that of WBC. Shorter co-incubation periods made cell-cycle progression intermediate between PLC and WBC values. Thus, PBCs modulate the baseline frequency of SCEs in human PLC and the cell-cycle progression of both human and pig lymphocytes in a time-dependent manner. Two possible hypotheses for the heightened frequency of SCEs of human lymphocytes in RBC-free cultures were assessed. The loss of RBC-to-lymphocyte cellular contact in PLC did not influence the SCE frequencies of lymphocytes. Finally, the increase of SCEs in human PLC could not be related to differences in the generation time of lymphocytes in culture.

  18. Long-term exposure to fluoride in drinking water and sister chromatid exchange frequency in human blood lymphocytes.

    PubMed

    Li, Y; Liang, C K; Katz, B P; Brizendine, E J; Stookey, G K

    1995-08-01

    The genetic toxicity of fluoride has been investigated extensively by various test systems. However, results obtained have been inconsistent. Fluoride has been reported to be non-genotoxic, genotoxic, and synergistic or antagonistic with certain mutagens. To date, there are no published human studies on the genotoxicity of fluoride. The purpose of this investigation was to determine genotoxic risks of long-term exposure to various concentrations of fluoride in drinking water in humans with normal or inadequate nutrition. Six groups of subjects with either normal or inadequate nutritional intakes were selected from areas of approximately 0.2, 1.0, or 4.8 ppm (10.5, 52.6, or 252.6 mumol/L) fluoride in water. The subjects had been continuous residents in the area for at least 35 years. Samples of drinking water, plasma, and urine were analyzed for fluoride content. Blood lymphocytes were examined to determine the frequency of sister chromatid exchange (SCE). Blood chemistry and electrolytes were also analyzed. The results showed that average daily fluoride intake as well as urine and plasma fluoride levels increased with increase in the fluoride content of the drinking water. The blood chemistry and electrolyte values were within the normal range for all populations, but several parameters were significantly different. While the numerical differences were small, the subjects with low fluoride in the water (0.11 and 0.23 ppm or 5.8 and 12.1 mumol/L) had significantly higher SCE frequencies than those with higher fluoride exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. 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.

  20. 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.

  1. Induction of micronuclei and sister chromatid exchange in bone-marrow cells and abnormalities in sperm of Algerian mice (Mus spretus) exposed to cadmium, lead and zinc.

    PubMed

    Tapisso, Joaquim Torres; Marques, Carla Cristina; Mathias, Maria da Luz; Ramalhinho, Maria da Graça

    2009-08-01

    As a consequence of human activities, large amounts of cadmium, lead and zinc are released in the environment, often simultaneously. The aim of this study was to investigate under experimental conditions the DNA damage induced in Algerian mice (Mus spretus) exposed to cadmium (Cd), lead (Pb) and zinc (Zn) separately, or in selected combinations. Three cytogenetic end points were considered: the frequencies of micronucleated cells (MN) and sister chromatid exchange (SCE) in the bone marrow and the frequency of sperm abnormalities. Mice were treated by intraperitoneal (i.p.) injections with 5 or 10 doses of aqueous solutions of cadmium acetate, lead acetate and zinc acetate in concentrations corresponding to 1/10 of the LD50, respectively, 21.5, 0.46 and 1.5 mg/kg bw. The control groups were injected in the same way with distilled water. With only one exception (Cd + Zn group treated with 5 doses), the results show a significant increase of MN in all groups for both treatments (5 and 10 doses). Similarly, the results concerning the SCE revealed a statistically significant increase in all treated animals, with the exception of the Zn group treated with 5 doses. The number of sperm abnormalities was significantly higher in animals treated with 5 doses, except in the group Pb + Zn. In animals treated with 10 doses the number of sperm abnormalities was always statistically higher compared with controls. This study indicates that cadmium, lead and zinc can induce MN, SCEs and sperm abnormalities in Algerian mice and that the clastogenic potential is dependent on the time of exposure and the interaction between the three elements, confirming the environmental damage that may result from the simultaneous action of several metals. Most relevant is the toxic potential for Zn, related with the dose, which may compromise its protective effect against other metal contaminations, such as cadmium.

  2. Mutagenicity in Salmonella and sister chromatid exchange in mice for 1,4-, and 1,3-, 2,4-, and 3,4-dimethylphenanthrenes

    SciTech Connect

    Sinsheimer, J.E.; Giri, A.K.; Hooberman, B.H.; Jung, K.Y.; Gopalaswamy, R.; Koreeda, M. )

    1991-01-01

    The mutagenicity in Salmonella and in vivo sister chromatid exchange in the bone-marrow cells of mice was determined for 1,4-, 1,3-, 2,4-, and 3,4-dimethylphenanthrene (DMPh) with the objective to study the relative importance of substitution at the 1 and 4 positions of this series of methylated phenanthrenes. For both tests, 1,4-DMPh was decidedly more genotoxic than the remaining regioisomers. While the well recognized role of steric crowding in the bay region is a factor in this enhanced genotoxicity, equally important is substitution at the 1 position with its potential to inhibit detoxication through 9,10-diol formation.

  3. Sister chromatid exchange assay. January 1978-April 1990 (A Bibliography from the NTIS data base). Report for January 1978-April 1990

    SciTech Connect

    Not Available

    1990-04-01

    This bibliography contains citations concerning use of the sister chromatid exchange (SCE) assay for toxicological studies. SCE assays are very sensitive measures of genotoxic damage to chromosomes. SCE toxicological studies analyzing vinyl carbamate, nerve gas, tritium, chlorofluorocarbons, sewage sludge, arsenic, ionizing radiation, ethylene oxide, microwave radiation, coal and oil fly ash, heavy metals, and sodium azide are discussed. SCE studies using both human and animal tissue cultures are described. SCE studies in the developing fetus, and improved SCE techniques are also described. (Contains 146 citations fully indexed and including a title list.)

  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. Radiation induces premature chromatid separation via the miR-142-3p/Bod1 pathway in carcinoma cells

    PubMed Central

    Pan, Dong; Du, Yarong; Ren, Zhenxin; Chen, Yaxiong; Li, Xiaoman; Wang, Jufang; Hu, Burong

    2016-01-01

    Radiation-induced genomic instability plays a vital role in carcinogenesis. Bod1 is required for proper chromosome biorientation, and Bod1 depletion increases premature chromatid separation. MiR-142-3p influences cell cycle progression and inhibits proliferation and invasion in cervical carcinoma cells. We found that radiation induced premature chromatid separation and altered miR-142-3p and Bod1 expression in 786-O and A549 cells. Overexpression of miR-142-3p increased premature chromatid separation and G2/M cell cycle arrest in 786-O cells by suppressing Bod1 expression. We also found that either overexpression of miR-142-3p or knockdown of Bod1 sensitized 786-O and A549 cells to X-ray radiation. Overexpression of Bod1 inhibited radiation- and miR-142-3p-induced premature chromatid separation and increased resistance to radiation in 786-O and A549 cells. Taken together, these results suggest that radiation alters miR-142-3p and Bod1 expression in carcinoma cells, and thus contributes to early stages of radiation-induced genomic instability. Combining ionizing radiation with epigenetic regulation may help improve cancer therapies. PMID:27527863

  6. Chromatid breaks induced in Chinese hamster cells by low doses (12--100 rad) of pi--mesons.

    PubMed

    Mindek, G; Blattmann, H; Cordt, I; Fritz-Niggli, H

    1979-08-10

    Monolayer cultures of the fibroblast-like Chinese hamster cell-line 19/1 were irradiated in the G2-phase of the cell cycle by pi--mesons (6 rad/min peak-pion dose rate). Frequencies of induced single- and isochromatid breaks, acentric fragments and interchanges were compared with data obtained from 140 kV X-rays. The RBE-values were for the pion dose peak between 0.8--1.2 and for the pion dose plateau 0.5--0.9. Whereas for single chromatid breaks there was no significant difference between X-rays and peak pions for identical physical doses, the isochromatid breaks alone showed a significantly higher frequency for 100 rad peak pions.

  7. 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.

  8. Effects of radiofrequency radiation and simultaneous exposure with mitomycin C on the frequency of sister chromatid exchanges in Chinese hamster ovary cells

    SciTech Connect

    Ciaravino, V.; Meltz, M.L.; Erwin, D.N.

    1987-01-01

    Chinese hamster ovary (CHO) cells were exposed for 2 hr with and without mitomycin C (MMC) to pulsed wave radiofrequency radiation (RFR) at 2450 MHz. The repetition rate of 25,000 pulses per sec (pps), and exposure geometry used, resulted in a specific absorption rate (SAR) of 33.8 W/kg. The following exposure regimens were used: 1) a 37 C water bath control; 2) a water bath temperature control (TC) in which the continuously monitored medium temperature closely followed teh temperature rise in the RFR-exposed flasks; and 3) the RFR-exposed cells in a water bath set at 37 C prior to exposure. RFR exposure resulted in a maximum cell culture medium temperature of 39.2 C. In the absence of MMC, there was no significant increase in sister chromatid exchange (SCE) in the RFR-exposed or TC groups over that of teh 37 C control. When a simultaneous treatment of RFR and MMC occurred there was no statistical difference in SCE frequency from that caused by chemical treatment alone.

  9. Effects of radiofrequency radiation and simultaneous exposure with mitomycin C on the frequency of sister chromatid exchanges in Chinese hamster ovary cells

    SciTech Connect

    Ciaravino, V.; Meltz, M.L.; Erwin, D.N.

    1987-01-01

    Chinese hamster ovary (CHO) cells were exposed for 2 hr with and without mitomycin C (MMC) (1 X 10(-8)M) to pulsed wave radiofrequency radiation (RFR) at 2450 MHz. The repetition rate of 25,000 pulses per sec (pps), pulse width of 10 microseconds, and exposure geometry used, resulted in a specific absorption rate (SAR) of 33.8 W/kg. The following exposure regimens were used: a 37 degrees C water bath control; a water bath temperature control (TC) in which the continuously monitored medium temperature closely followed the temperature rise in the RFR-exposed flasks; and the RFR-exposed cells in a water bath set at 37 degrees C prior to exposure. RFR exposure resulted in a maximum cell culture medium temperature of 39.2 degrees C. In the absence of MMC, there was no significant increase in sister chromatid exchange (SCE) in the RFR-exposed or TC groups over that of the 37 degrees C control. When a simultaneous treatment of RFR and MMC occurred there was no statistical difference in SCE frequency from that caused by chemical treatment alone.

  10. 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.

  11. Targeting of chemical mutagens to differentiating B-lymphocytes in vivo: detection by direct DNA labeling and sister chromatid exchange induction

    SciTech Connect

    Bloom, S.E.; Nanna, U.C.; Dietert, R.R.

    1987-01-01

    In vivo systems for analyzing mutagen interactions with a specific differentiating cell population are rare. Taking advantage of the unique anatomical features of the bursa of Fabricius in the chicken, the authors explored the possibility of targeting chemical mutagens to a defined differentiating cell population in the animal, namely, the B-lymphocytes series. Such cells are known to be the targets for the oncogene-activating avian leukosis virus. Targeting of chemicals to cells of the bursa was demonstrated by application of the DNA-specific fluorochrome 4'-6-diamidino-2-phenylindole (DAPI) to the anal lips of neonatal chicks. Bright nuclear fluorescence of cells in the bursa demonstrated to occur within minutes after the application of 500..mu..l of DAPI. DAPI labeling of nuclei was detected up to several days after a single application. No nuclear labeling was exhibited in cells of neighboring tissues. Methyl methanesulfonate (MMS)(10..mu..l) was applied to the anal lips of day-old chicks to study dose-response kinetics for mutagen targeting to DNA of dividing B-lymphocytes in the bursa. Since the mitotic index was found to be quite high (25-30%) in the bursa, chromosome analysis was used to assay for genome damage. Sister chromatid exchange frequencies of 3.9, 7.3, and 9.0 (baseline 2.5) per cell were obtained at MMS dosages per animal of 50 ..mu..g, 100..mu..g, and 200..mu..g, respectively. These results indicate the rapid and quantitative localization of DNA-binding chemicals to cells of the bursa, particularly the resident B-lymphocytes. The bursa should be a useful system for studying mutagen-DNA interactions in the differentiating B-lymphocyte and subsequent influences on the development of immunity and lymphoproliferative disease.

  12. 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.

  13. 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.

  14. Investigation of Homologous Crossing over and Sister Chromatid Exchange in the Wheat Nor-B2 Locus Coding for Rrna and Gli-B2 Locus Coding for Gliadins

    PubMed Central

    Dvořák, J.; Appels, R.

    1986-01-01

    Recombination was investigated within the Nor-B2 locus of wheat chromosome 6B that contains several thousand of the 18S-5.8S-26S rRNA (rDNA) repeated units. Additionally, recombination was assessed for several chromosome regions, in arm 6Bq between the centromere and the B2 locus (awn suppressor) and in arm 6Bp between the centromere and Nor-B2, between Nor-B2 and a distal C-band and between Nor-B2 and Gli-B2 coding for gliadins. The experimental design permitted the distinction between crossing over between homologous chromosomes and exchange between sister chromatids. No homologous crossing over within the Nor-B2 locus was found in a sample of 446 chromosomes, but one exchange with the attributes of unequal sister chromatid exchange was identified. The molecular characteristics of this presumed sister chromatid exchange indicate that the spacer variants present in the Nor-B2 locus are clustered. No homologous recombination was detected within the distal Gli-B2 locus containing repeated genes coding for gliadin seed-storage proteins. Both arms of chromosome 6B showed low crossing-over frequency in the proximal regions. The distance from the centromere to Nor-B2 was only from 0.3 to 2.2 cM although it accounts for about two-thirds of the metaphase chromosome arm, which shows a great distortion of the metaphase map of the arm. The level of homologous recombination within the Nor-B2 locus is lower than in the chromosome region immediately distal to it. Whether it is comparable to that in the chromosome region proximal to it could not be determined. Recombination frequencies of different pairs of chromosome 6B in all but one interval paralleled the frequencies of their metaphase I pairing: Lower pairing at metaphase I was paralleled by lower crossing-over frequency. This relationship indicated that reduced metaphase I pairing between 6B chromosomes from different populations is due to impaired crossing-over and not due to precocious chiasma terminalization. PMID

  15. Enhancement and reduction by methylated oxypurines of the frequencies of chromatid aberrations induced by camptothecin in root-tip cells of Vicia faba.

    PubMed

    Kihlman, B A; Andersson, H C

    1992-10-01

    In root-tip cells of Vicia faba the frequencies of chromatid aberrations induced by 3-h treatments with 0.05 microM camptothecin were strongly modified when the treatments were carried out in the presence of caffeine at concentrations above 1 mM. Depending on the concentration of caffeine, the clastogenic effect of camptothecin was either enhanced or reduced. At concentrations between 1 and 6 mM, caffeine increased the camptothecin-induced chromosome damage, the strongest enhancement being obtained at 5 mM. A reduction of the chromosome damage was apparent at caffeine concentrations above 10 mM, and in the presence of 20 mM caffeine the clastogenic effect of camptothecin was almost completely suppressed. When present during the camptothecin treatment, theophylline, 8-chlorocaffeine and 1,3,7,9-tetramethyluric acid influenced the induced chromosome damage in a similar way as caffeine, although with varying efficiency. If the concentrations required to produce the two types of modifying effect are used as a criterion, 8-chlorocaffeine was the most effective and 1,3,7,9-tetramethyluric acid the least, whereas caffeine and theophylline were about equally effective.

  16. Nonrandom sister chromatid segregation of sex chromosomes in Drosophila male germline stem cells.

    PubMed

    Yamashita, Yukiko M

    2013-05-01

    Sister chromatids are the product of DNA replication, which is assumed to be a very precise process. Therefore, sister chromatids should be exact copies of each other. However, reports have indicated that sister chromatids are segregated nonrandomly during cell division, suggesting that sister chromatids are not the same, although their DNA sequences are the same. Researchers have speculated that stem cells may retain template strands to avoid replication-induced mutations. An alternative proposal is that cells may segregate distinct epigenetic information carried on sister chromatids. Recently, we found that Drosophila male germline stem cells segregate sister chromatids of X and Y chromosomes with a strong bias. We discuss this finding in relation to existing models for nonrandom sister chromatid segregation.

  17. Examination of naturally occurring polyacetylenes and alpha-terthienyl for their ability to induce cytogenetic damage.

    PubMed

    MacRae, W D; Chan, G F; Wat, C K; Towers, G H; Lam, J

    1980-09-15

    alpha-Terthienyl and 5 polyacetylenes were examined for chromosome damaging activity using Syrian hamster cells. None of these naturally occurring compounds induced sister chromatid exchanges and neither alpha-terthienyl nor phenylheptatriyne induced chromosome aberrations.

  18. Similar Sister Chromatid Arrangement in Mono- and Holocentric Plant Chromosomes.

    PubMed

    Schubert, Veit; Zelkowski, Mateusz; Klemme, Sonja; Houben, Andreas

    2016-01-01

    Due to the X-shape formation at somatic metaphase, the arrangement of the sister chromatids is obvious in monocentric chromosomes. In contrast, the sister chromatids of holocentric chromosomes cannot be distinguished even at mitotic metaphase. To clarify their organization, we differentially labelled the sister chromatids of holocentric Luzula and monocentric rye chromosomes by incorporating the base analogue EdU during replication. Using super-resolution structured illumination microscopy (SIM) and 3D rendering, we found that holocentric sister chromatids attach to each other at their contact surfaces similar to those of monocentrics in prometaphase. We found that sister chromatid exchanges (SCEs) are distributed homogeneously along the whole holocentric chromosomes of Luzula, and that their occurrence is increased compared to monocentric rye chromosomes. The SCE frequency of supernumerary B chromosomes, present additionally to the essential A chromosome complement of rye, does not differ from that of A chromosomes. Based on these results, models of the sister chromatid arrangement in mono- and holocentric plant chromosomes are presented.

  19. Cell elongation is an adaptive response for clearing long chromatid arms from the cleavage plane.

    PubMed

    Kotadia, Shaila; Montembault, Emilie; Sullivan, William; Royou, Anne

    2012-11-26

    Chromosome segregation must be coordinated with cell cleavage to ensure correct transmission of the genome to daughter cells. Here we identify a novel mechanism by which Drosophila melanogaster neuronal stem cells coordinate sister chromatid segregation with cleavage furrow ingression. Cells adapted to a dramatic increase in chromatid arm length by transiently elongating during anaphase/telophase. The degree of cell elongation correlated with the length of the trailing chromatid arms and was concomitant with a slight increase in spindle length and an enlargement of the zone of cortical myosin distribution. Rho guanine-nucleotide exchange factor (Pebble)-depleted cells failed to elongate during segregation of long chromatids. As a result, Pebble-depleted adult flies exhibited morphological defects likely caused by cell death during development. These studies reveal a novel pathway linking trailing chromatid arms and cortical myosin that ensures the clearance of chromatids from the cleavage plane at the appropriate time during cytokinesis, thus preserving genome integrity.

  20. 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

  1. Effect of interleukin-2 on cell proliferation, sister-chromatid exchange induction, and nuclear stress protein phosphorylation in PHA-stimulated Fischer 344 rat spleen lymphocytes: Modulation by 2-mercaptoethanol

    SciTech Connect

    Morris, S.M.; Aidoo, A.; Domon, O.E.; McGarrity, L.J.; Kodell, R.L.; Schol, H.M.; Hinson, W.G.; Pipkin, J.L.; Casciano, D.A. )

    1990-01-01

    The effect of interleukin-2 (IL-2) on cell proliferation, sister-chromatid exchange (SCE) frequency, and the phosphorylation of nuclear stress proteins was evaluated in phytohemagglutinin (PHA)-stimulated spleen lymphocytes isolated from Fischer 344 rats. In addition, the ability of 2-mercaptoethanol (2-ME) to modulate the induction of these biological responses was characterized. Cell proliferation, as measured by the mitotic index, increased significantly. The average generation time (AGT) did not respond to IL-2 in a concentration-dependent manner and decreased significantly. The number of SCE increased significantly from control frequencies, to frequencies of 18.5 to 21.5 SCE per cell as the concentration of IL-2 in the culture medium increased to 50 half-maximal units per ml. A reduction in SCE frequency was observed when cells were cultured with 20 {mu}M 2-ME and IL-2 compared to IL-2 alone. Three nuclear proteins, with relative molecular masses of approximately 13,000-18,000, 20,000, and 80,000, were phosphorylated in IL-2-exposed G{sub 1}-phase nuclei. Elicitation of these nuclear proteins in IL-2-exposed cells was not affected by exposure to 2-ME.

  2. 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.

  3. [Hyperreninemic hypoaldosteronism syndrome induced by plasma exchange].

    PubMed

    Fourrier, F; Leclerc, L; Racadot, A; Wemeau, J L; Lestavel, P; Chopin, C

    1988-10-08

    The study was designed to measure sequential changes in plasma renin activity, aldosterone, angiotensin-converting enzyme activity and ionograms, prior to, and after therapeutic plasma exchange. Each measurement was repeated before and after stimulation of renin activity induced by furosemide. The results showed that plasma exchange induces a syndrome of hyperreninemic hypoaldosteronism associated with a depletion in angiotensin-converting enzyme activity which might account for the dissociation between plasma renin activity and aldosterone.

  4. Premature chromatid separation and altered proliferation of human leukocytes treated with vanadium (III) oxide.

    PubMed

    Mateos-Nava, Rodrigo Anibal; Rodríguez-Mercado, Juan José; Altamirano-Lozano, Mario Agustín

    2016-12-12

    Vanadium is a widely distributed metal in the Earth's surface and is released into the environment by either natural or anthropogenic causes. Vanadium (III) oxide (V2O3) is present in the environment, and many organisms are exposed to this compound; however, its effects at the cellular and genetic levels are still unknown. Therefore, in this study, the ability of V2O3 to induce chromosomal damage and impair cell proliferation was tested on human leukocytes in vitro. The cultures cells were treated for 48 h with different concentrations 2, 4, 8 or 16 μg/mL of V2O3, and we use the sister chromatid exchange's (SCE) test and the viability assay to evaluate the effects. In the results, no change was observed in either the viability or the frequency of SCE; however, a significant increase was observed in the incidence of premature chromatid separation (PCS), and a decrease was observed in both the mitotic index (MI) and the replication index (RI). Therefore, it can be suggested that V2O3 induces a genotoxic effect at the centromere level, indicating that it is a cause of aneuploidy that is capable of altering cell cycle progression.

  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. Dipolar exchange induced transparency with Rydberg atoms

    NASA Astrophysics Data System (ADS)

    Petrosyan, David

    2017-03-01

    A three-level atomic medium can be made transparent to a resonant probe field in the presence of a strong control field acting on an adjacent atomic transition to a long-lived state, which can be represented by a highly excited Rydberg state. The long-range interactions between the Rydberg state atoms then translate into strong, non-local, dispersive or absorptive interactions between the probe photons, which can be used to achieve deterministic quantum logic gates and single photon sources. Here we show that long-range dipole–dipole exchange interaction with one or more spins—two-level systems represented by atoms in suitable Rydberg states—can play the role of control field for the optically dense medium of atoms. This induces transparency of the medium for a number of probe photons n p not exceeding the number of spins n s , while all the excess photons are resonantly absorbed upon propagation. In the most practical case of a single spin atom prepared in the Rydberg state, the medium is thus transparent only to a single input probe photon. For larger number of spins n s , all n p ≤ n s photon components of the probe field would experience transparency but with an n p -dependent group velocity.

  8. 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.

  9. Survival and initial chromatid breakage in normal and tumour cells exposed in vitro to gamma rays and carbon ions at the HIRFL.

    PubMed

    Jianshe, Y; Wenjian, L; Xiaodong, J; Xigang, J; Chuanling, G; Wei, W; Qingxiang, G

    2006-06-01

    Human hepatoma and normal liver cells were irradiated with (12)C(6+) ion beams (linear energy transfer (LET) = 96 keV microm(-1)) and gamma-rays at the Heavy Ion Research Facility in Lanzhou (HIRFL). The numbers and types of chromatid breaks were detected using the premature chromosome condensation technique. Irradiation with (12)C(6+) ions produced a majority of isochromatid break types, while chromatid breaks were dominant for irradiation with gamma-rays. Experimental results showed that the initial level of chromatid breaks is clearly related to the absorbed dose from (12)C(6+) ions and gamma-rays. The (12)C(6+) ions are relatively more effective at inducing initial chromatid breaks when compared with the gamma-rays. A relative biological effectiveness (RBE) of about 2.5 resulted for the induction of initial chromatid breaks by (12)C(6+) ions relative to gamma-rays in both cell lines.

  10. Management of E. coli sister chromatid cohesion in response to genotoxic stress

    PubMed Central

    Vickridge, Elise; Planchenault, Charlene; Cockram, Charlotte; Junceda, Isabel Garcia; Espéli, Olivier

    2017-01-01

    Aberrant DNA replication is a major source of the mutations and chromosomal rearrangements associated with pathological disorders. In bacteria, several different DNA lesions are repaired by homologous recombination, a process that involves sister chromatid pairing. Previous work in Escherichia coli has demonstrated that sister chromatid interactions (SCIs) mediated by topological links termed precatenanes, are controlled by topoisomerase IV. In the present work, we demonstrate that during the repair of mitomycin C-induced lesions, topological links are rapidly substituted by an SOS-induced sister chromatid cohesion process involving the RecN protein. The loss of SCIs and viability defects observed in the absence of RecN were compensated by alterations in topoisomerase IV, suggesting that the main role of RecN during DNA repair is to promote contacts between sister chromatids. RecN also modulates whole chromosome organization and RecA dynamics suggesting that SCIs significantly contribute to the repair of DNA double-strand breaks (DSBs). PMID:28262707

  11. 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.

  12. Sister chromatid separation in frog egg extracts requires DNA topoisomerase II activity during anaphase

    PubMed Central

    1992-01-01

    We have produced metaphase spindles and induced them to enter anaphase in vitro. Sperm nuclei were added to frog egg extracts, allowed to replicate their DNA, and driven into metaphase by the addition of cytoplasm containing active maturation promoting factor (MPF) and cytostatic factor (CSF), an activity that stabilizes MPF. Addition of calcium induces the inactivation of MPF, sister chromatid separation and anaphase chromosome movement. DNA topoisomerase II inhibitors prevent chromosome segregation at anaphase, demonstrating that the chromatids are catenated at metaphase and that decatenation occurs at the start of anaphase. Topoisomerase II activity towards exogenous substrates does not increase at the metaphase to anaphase transition, showing that chromosome separation at anaphase is not triggered by a bulk activation of topoisomerase II. PMID:1315785

  13. Alternative meiotic chromatid segregation in the holocentric plant Luzula elegans

    PubMed Central

    Heckmann, Stefan; Jankowska, Maja; Schubert, Veit; Kumke, Katrin; Ma, Wei; Houben, Andreas

    2014-01-01

    Holocentric chromosomes occur in a number of independent eukaryotic lineages. They form holokinetic kinetochores along the entire poleward chromatid surfaces, and owing to this alternative chromosome structure, species with holocentric chromosomes cannot use the two-step loss of cohesion during meiosis typical for monocentric chromosomes. Here we show that the plant Luzula elegans maintains a holocentric chromosome architecture and behaviour throughout meiosis, and in contrast to monopolar sister centromere orientation, the unfused holokinetic sister centromeres behave as two distinct functional units during meiosis I, resulting in sister chromatid separation. Homologous non-sister chromatids remain terminally linked after metaphase I, by satellite DNA-enriched chromatin threads, until metaphase II. They then separate at anaphase II. Thus, an inverted sequence of meiotic sister chromatid segregation occurs. This alternative meiotic process is most likely one possible adaptation to handle a holocentric chromosome architecture and behaviour during meiosis. PMID:25296379

  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. Sororin actively maintains sister chromatid cohesion.

    PubMed

    Ladurner, Rene; Kreidl, Emanuel; Ivanov, Miroslav P; Ekker, Heinz; Idarraga-Amado, Maria Helena; Busslinger, Georg A; Wutz, Gordana; Cisneros, David A; Peters, Jan-Michael

    2016-03-15

    Cohesion between sister chromatids is established during DNA replication but needs to be maintained to enable proper chromosome-spindle attachments in mitosis or meiosis. Cohesion is mediated by cohesin, but also depends on cohesin acetylation and sororin. Sororin contributes to cohesion by stabilizing cohesin on DNA. Sororin achieves this by inhibiting WAPL, which otherwise releases cohesin from DNA and destroys cohesion. Here we describe mouse models which enable the controlled depletion of sororin by gene deletion or auxin-induced degradation. We show that sororin is essential for embryonic development, cohesion maintenance, and proper chromosome segregation. We further show that the acetyltransferases ESCO1 and ESCO2 are essential for stabilizing cohesin on chromatin, that their only function in this process is to acetylate cohesin's SMC3 subunit, and that DNA replication is also required for stable cohesin-chromatin interactions. Unexpectedly, we find that sororin interacts dynamically with the cohesin complexes it stabilizes. This implies that sororin recruitment to cohesin does not depend on the DNA replication machinery or process itself, but on a property that cohesin acquires during cohesion establishment.

  16. Chromatid damage in human lymphocytes is not affected by 50 Hz electromagnetic fields.

    PubMed

    Hone, P; Lloyd, D; Szłuińska, M; Edwards, A

    2006-01-01

    Cultured human blood lymphocytes were exposed during the S/G(2) phases of the cell cycle to continuous extremely low frequency (50 Hz) electromagnetic fields of 0.23, 0.47 or 0.7 mT either alone or immediately after an acute exposure to 1.0 Gy of gamma rays. The ionising radiation, as expected, induced chromosomal aberrations of the chromatid-type observed at the next metaphase. The field applied alone did not induce chromosomal damage nor did it modify the frequency of aberrations caused by the gamma rays.

  17. Sister chromatid resolution: a cohesin releasing network and beyond.

    PubMed

    Shintomi, Keishi; Hirano, Tatsuya

    2010-10-01

    When chromosomes start to assemble in mitotic prophase, duplicated chromatids are not discernible within each chromosome. As condensation proceeds, they gradually show up, culminating in two rod-shaped structures apposed along their entire length within a metaphase chromosome. This process, known as sister chromatid resolution, is thought to be a prerequisite for rapid and synchronous separation of sister chromatids in anaphase. From a mechanistic point of view, the resolution process can be dissected into three distinct steps: (1) release of cohesin from chromosome arms; (2) formation of chromatid axes mediated by condensins; and (3) untanglement of inter-sister catenation catalyzed by topoisomerase II (topo II). In this review article, we summarize recent progress in our understanding the molecular mechanisms of sister chromatid resolution with a major focus on its first step, cohesin release. An emerging idea is that this seemingly simple step is regulated by an intricate network of positive and negative factors, including cohesin-binding proteins and mitotic kinases. Interestingly, some key factors responsible for cohesin release in early mitosis also play important roles in controlling cohesin functions during interphase. Finally, we discuss how the step of cohesin release might mechanistically be coordinated with the actions of condensins and topo II.

  18. The cohesin subunit Rad21 is required for synaptonemal complex maintenance, but not sister chromatid cohesion, during Drosophila female meiosis.

    PubMed

    Urban, Evelin; Nagarkar-Jaiswal, Sonal; Lehner, Christian F; Heidmann, Stefan K

    2014-08-01

    Replicated sister chromatids are held in close association from the time of their synthesis until their separation during the next mitosis. This association is mediated by the ring-shaped cohesin complex that appears to embrace the sister chromatids. Upon proteolytic cleavage of the α-kleisin cohesin subunit at the metaphase-to-anaphase transition by separase, sister chromatids are separated and segregated onto the daughter nuclei. The more complex segregation of chromosomes during meiosis is thought to depend on the replacement of the mitotic α-kleisin cohesin subunit Rad21/Scc1/Mcd1 by the meiotic paralog Rec8. In Drosophila, however, no clear Rec8 homolog has been identified so far. Therefore, we have analyzed the role of the mitotic Drosophila α-kleisin Rad21 during female meiosis. Inactivation of an engineered Rad21 variant by premature, ectopic cleavage during oogenesis results not only in loss of cohesin from meiotic chromatin, but also in precocious disassembly of the synaptonemal complex (SC). We demonstrate that the lateral SC component C(2)M can interact directly with Rad21, potentially explaining why Rad21 is required for SC maintenance. Intriguingly, the experimentally induced premature Rad21 elimination, as well as the expression of a Rad21 variant with destroyed separase consensus cleavage sites, do not interfere with chromosome segregation during meiosis, while successful mitotic divisions are completely prevented. Thus, chromatid cohesion during female meiosis does not depend on Rad21-containing cohesin.

  19. The Cohesin Subunit Rad21 Is Required for Synaptonemal Complex Maintenance, but Not Sister Chromatid Cohesion, during Drosophila Female Meiosis

    PubMed Central

    Lehner, Christian F.; Heidmann, Stefan K.

    2014-01-01

    Replicated sister chromatids are held in close association from the time of their synthesis until their separation during the next mitosis. This association is mediated by the ring-shaped cohesin complex that appears to embrace the sister chromatids. Upon proteolytic cleavage of the α-kleisin cohesin subunit at the metaphase-to-anaphase transition by separase, sister chromatids are separated and segregated onto the daughter nuclei. The more complex segregation of chromosomes during meiosis is thought to depend on the replacement of the mitotic α-kleisin cohesin subunit Rad21/Scc1/Mcd1 by the meiotic paralog Rec8. In Drosophila, however, no clear Rec8 homolog has been identified so far. Therefore, we have analyzed the role of the mitotic Drosophila α-kleisin Rad21 during female meiosis. Inactivation of an engineered Rad21 variant by premature, ectopic cleavage during oogenesis results not only in loss of cohesin from meiotic chromatin, but also in precocious disassembly of the synaptonemal complex (SC). We demonstrate that the lateral SC component C(2)M can interact directly with Rad21, potentially explaining why Rad21 is required for SC maintenance. Intriguingly, the experimentally induced premature Rad21 elimination, as well as the expression of a Rad21 variant with destroyed separase consensus cleavage sites, do not interfere with chromosome segregation during meiosis, while successful mitotic divisions are completely prevented. Thus, chromatid cohesion during female meiosis does not depend on Rad21-containing cohesin. PMID:25101996

  20. 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.

  1. Sister chromatid separation: falling apart at the seams.

    PubMed

    Cohen-Fix, O

    2000-11-16

    Cohesion between sister chromatids must be dissolved at the time of chromosome segregation. Recent studies reveal that the principles of cohesion dissolution in mitosis and meiosis are the same, but that there are important differences that stem from the distinct natures of these two processes.

  2. 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.

  3. 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.

  4. Influence of ion bombardment induced patterning of exchange bias in pinned artificial ferrimagnets on the interlayer exchange coupling

    SciTech Connect

    Hoeink, V.; Schmalhorst, J.; Reiss, G.; Weis, T.; Lengemann, D.; Engel, D.; Ehresmann, A.

    2008-06-15

    Artificial ferrimagnets have many applications as, e.g., pinned reference electrodes in magnetic tunnel junctions. It is known that the application of ion bombardment (IB) induced patterning of the exchange bias coupling of a single layer reference electrode in magnetic tunnel junctions with He ions is possible. For applications as, e.g., special types of magnetic logic, a combination of the IB induced patterning of the exchange bias coupling and the implementation of an artificial ferrimagnet as reference electrode is desirable. Here, investigations for a pinned artificial ferrimagnet with a Ru interlayer, which is frequently used in magnetic tunnel junctions, are presented. It is shown that in this kind of samples the exchange bias can be increased or rotated by IB induced magnetic patterning with 10 keV He ions without a destruction of the antiferromagnetic interlayer exchange coupling. An IrMn/Py/Co/Cu/Co stack turned out to be more sensitive to the influence of IB than the Ru based artificial ferrimagnet.

  5. 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.

  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. Angular dependence of exchange bias and magnetization reversal controlled by electric-field-induced competing anisotropies

    NASA Astrophysics Data System (ADS)

    Zhao, Yonggang; Chen, Aitian; Li, Peisen; Zhang, Xu; Peng, Renci; Huang, Haoliang; Zou, Lvkuan; Zheng, Xiaoli; Zhang, Sen; Miao, Peixian; Lu, Yalin; Cai, Jian; Nan, Ce-Wen

    Combination of exchange-biased systems and FE materials gives a new avenue to study angular dependence of exchange bias and achieve reversible electric-field-controlled magnetization reversal. We study the angular dependence of electric-field-controlled exchange bias and magnetization reversal in CoFeB/IrMn/Pb(Mg1/3Nb2/3)0.7 Ti0.3O3. It is demonstrated that the ratio of the exchange-coupled unidirectional anisotropy and the uniaxial anisotropy of the FM layer, as well as their relative orientation can be dramatically and continuously tuned via electric fields. Simulations confirm that the electric-field-controlled exchange bias originates from the competition between the uniaxial anisotropy induced by the piezostrain and the exchange-coupled unidirectional anisotropy. Moreover, electric-field-controlled magnetization reversal was realized at zero magnetic field.

  8. Transverse relaxation in the rotating frame induced by chemical exchange

    NASA Astrophysics Data System (ADS)

    Michaeli, Shalom; Sorce, Dennis J.; Idiyatullin, Djaudat; Ugurbil, Kamil; Garwood, Michael

    2004-08-01

    In the presence of radiofrequency irradiation, relaxation of magnetization aligned with the effective magnetic field is characterized by the time constant T1 ρ. On the other hand, the time constant T2 ρ characterizes the relaxation of magnetization that is perpendicular to the effective field. Here, it is shown that T2 ρ can be measured directly with Carr-Purcell sequences composed of a train of adiabatic full-passage (AFP) pulses. During adiabatic rotation, T2 ρ characterizes the relaxation of the magnetization, which under adiabatic conditions remains approximately perpendicular to the time-dependent effective field. Theory is derived to describe the influence of chemical exchange on T2 ρ relaxation in the fast-exchange regime, with time constant defined as T2 ρ,ex . The derived theory predicts the rate constant R 2ρ, ex (=1/T 2ρ, ex) to be dependent on the choice of amplitude- and frequency-modulation functions used in the AFP pulses. Measurements of R2 ρ,ex of the water/ethanol exchanging system confirm the predicted dependence on modulation functions. The described theoretical framework and adiabatic methods represent new tools to probe exchanging systems.

  9. Sororin pre-mRNA splicing is required for proper sister chromatid cohesion in human cells.

    PubMed

    Watrin, Erwan; Demidova, Maria; Watrin, Tanguy; Hu, Zheng; Prigent, Claude

    2014-09-01

    Sister chromatid cohesion, which depends on cohesin, is essential for the faithful segregation of replicated chromosomes. Here, we report that splicing complex Prp19 is essential for cohesion in both G2 and mitosis, and consequently for the proper progression of the cell through mitosis. Inactivation of splicing factors SF3a120 and U2AF65 induces similar cohesion defects to Prp19 complex inactivation. Our data indicate that these splicing factors are all required for the accumulation of cohesion factor Sororin, by facilitating the proper splicing of its pre-mRNA. Finally, we show that ectopic expression of Sororin corrects defective cohesion caused by Prp19 complex inactivation. We propose that the Prp19 complex and the splicing machinery contribute to the establishment of cohesion by promoting Sororin accumulation during S phase, and are, therefore, essential to the maintenance of genome stability.

  10. 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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5193219','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5193219"><span id="translatedtitle">Analysis of meiotic sister <span class="hlt">chromatid</span> cohesion in Caenorhabditis elegans</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Severson, Aaron F.</p> <p>2016-01-01</p> <p>In sexually reproducing organisms, the formation of healthy gametes (sperm and eggs) requires the proper establishment and release of meiotic sister <span class="hlt">chromatid</span> cohesion (SCC). SCC tethers replicated sisters from their formation in premeiotic S phase until the stepwise removal of cohesion in anaphase of meiosis I and II allows the separation of homologs and then sisters. Defects in the establishment or release of meiotic cohesion cause chromosome segregation errors that lead to the formation of aneuploid gametes and inviable embryos. The nematode Caenorhabditis elegans is an excellent model for studies of meiotic sister <span class="hlt">chromatid</span> cohesion due to its genetic tractability and the excellent cytological properties of the hermaphrodite gonad. Moreover, mutants defective in the establishment or maintenance of meiotic SCC nevertheless produce abundant gametes, allowing analysis of the pattern of chromosome segregation. Here I will describe two approaches for analysis of meiotic cohesion in C. elegans. The first approach relies on cytology to detect and quantify defects in SCC. The second approach relies on PCR and restriction digests to identify embryos that inherited an incorrect complement of chromosomes due to aberrant meiotic chromosome segregation. Both approaches are sensitive enough to identify rare errors and precise enough to reveal distinctive phenotypes resulting from mutations that perturb meiotic SCC in different ways. The robust, quantitative nature of these assays should strengthen phenotypic comparisons of different meiotic mutants and enhance the reproducibility of data generated by different investigators. PMID:27797074</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhRvB..78k5306E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhRvB..78k5306E"><span id="translatedtitle">Optically <span class="hlt">induced</span> spin gates in coupled quantum dots using the electron-hole <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>Economou, Sophia E.; Reinecke, T. L.</p> <p>2008-09-01</p> <p>We propose a fast optically <span class="hlt">induced</span> two-qubit C-PHASE gate between two resident spins in a pair of coupled quantum dots. An excited bound state which extends over the two dots provides an effective electron-electron <span class="hlt">exchange</span> interaction. The gate is made possible by the electron-hole <span class="hlt">exchange</span> interaction, which isolates a single transition in the system. When combined with appropriate single-qubit rotations, this gate generates an entangled state of the two spins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvC..94e4002V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvC..94e4002V"><span id="translatedtitle">Nucleon-nucleon interaction with one-pion <span class="hlt">exchange</span> and instanton-<span class="hlt">induced</span> interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vanamali, C. S.; Kumar, K. B. Vijaya</p> <p>2016-11-01</p> <p>Singlet (S10) and triplet (S31) nucleon-nucleon potentials are obtained in the framework of the SU(2) nonrelativistic quark model using the resonating-group method in the Born-Oppenheimer approximation. The full Hamiltonian used in the investigation includes the kinetic energy, two-body confinement potential, one-gluon-<span class="hlt">exchange</span> potential (OGEP), one-pion <span class="hlt">exchange</span> potential (OPEP), and instanton <span class="hlt">induced</span> interaction (III), which includes the effect of quark <span class="hlt">exchange</span> between the nucleons. The contribution of the OGEP, III, and OPEP to the nucleon-nucleon adiabatic potential is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7066255','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7066255"><span id="translatedtitle">Effects of contrast medium on radiation-<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>Matsubara, S.; Suzuki, S.; Suzuki, H.; Kuwabara, Y.; Okano, T.</p> <p>1982-07-01</p> <p>The effects of contrast material (meglumine iothalamate) on radiation-<span class="hlt">induced</span> chromosome aberrations were investigated in studies on the lymphocytes of patients who had undergone diagnostic radiography and in in vitro experiments with diagnostic x rays and /sup 60/Co gamma rays. Chromosome and <span class="hlt">chromatid</span> aberrations were found to increase significantly with increasing concentrations of contrast material that were added at irradiation. However, the aberrations were not associated with elevation of the ratio of dicentric and ring chromosomes to the number of cells with unstable chromosome aberrations at the first mitosis. Lymphocytes irradiated in the absence of contrast material did not show an increase in chromosome-type aberrations when the agent was given in increasing concentrations during subsequent incubation, but there were greater numbers of <span class="hlt">chromatid</span> gaps and breaks. When lymphocytes were exposed to 400 R (103.2 mC/kg) of /sup 60/Co gamma rays, the presence of contrast agent did not increase the yield of dicentric and ring chromosomes, but <span class="hlt">induced</span> a marked delay in cell proliferation, especially in lymphocytes with more heavily damaged chromosomes. In additional examination, the contrast agent itself <span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in lymphocytes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3771506','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3771506"><span id="translatedtitle">Chromosome orientation fluorescence in situ hybridization (CO-FISH) to study sister <span class="hlt">chromatid</span> segregation in vivo</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Falconer, Ester; Chavez, Elizabeth; Henderson, Alexander; Lansdorp, Peter M.</p> <p>2013-01-01</p> <p>Previously, assays for sister <span class="hlt">chromatid</span> segregation patterns relied on incorporation of BrdU and indirect methods to infer segregation patterns after two cell divisions. Here we describe a method to differentially label sister <span class="hlt">chromatids</span> of murine cells and directly assay sister <span class="hlt">chromatid</span> segregation patterns following one cell division in vitro and in vivo by adaptation of the well-established CO-FISH (chromosome orientation fluorescent in situ hybridization) technique. 5-bromo-2′-deoxyuridine (BrdU) is incorporated into newly-formed DNA strands, followed by photolysis and exonuclease digestion to create single-stranded sister <span class="hlt">chromatids</span> containing parental template DNA only. Such single-stranded sister <span class="hlt">chromatids</span> are differentially labeled using unidirectional probes to major satellite sequences coupled to fluorescent markers. Differentially-labeled sister <span class="hlt">chromatids</span> in post-mitotic cells are visualized using fluorescence microscopy and sister <span class="hlt">chromatid</span> segregation patterns can be directly assayed after one cell division. This procedure requires four days for in vivo mouse tissues, and two days for in vitro cultured cells. PMID:20595964</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://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.osti.gov/scitech/biblio/153685','SCIGOV-STC'); return false;" href="https://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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145417','PMC'); return false;" href="https://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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5159554','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5159554"><span id="translatedtitle">Rad51 and Rad54 promote noncrossover recombination between centromere repeats on the same <span class="hlt">chromatid</span> to prevent isochromosome 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>Onaka, Atsushi T.; Toyofuku, Naoko; Inoue, Takahiro; Okita, Akiko K.; Sagawa, Minami; Su, Jie; Shitanda, Takeshi; Matsuyama, Rei; Zafar, Faria; Takahashi, Tatsuro S.; Masukata, Hisao; Nakagawa, Takuro</p> <p>2016-01-01</p> <p>Centromeres consist of DNA repeats in many eukaryotes. Non-allelic homologous recombination (HR) between them can result in gross chromosomal rearrangements (GCRs). In fission yeast, Rad51 suppresses isochromosome formation that occurs between inverted repeats in the centromere. However, how the HR enzyme prevents homology-mediated GCRs remains unclear. Here, we provide evidence that Rad51 with the aid of the Swi/Snf-type motor protein Rad54 promotes non-crossover recombination between centromere repeats to prevent isochromosome formation. Mutations in Rad51 and Rad54 epistatically increased the rates of isochromosome formation and chromosome loss. In sharp contrast, these mutations decreased gene conversion between inverted repeats in the centromere. Remarkably, analysis of recombinant DNAs revealed that rad51 and rad54 increase the proportion of crossovers. In the absence of Rad51, deletion of the structure-specific endonuclease Mus81 decreased both crossovers and isochromosomes, while the cdc27/pol32-D1 mutation, which impairs break-<span class="hlt">induced</span> replication, did not. We propose that Rad51 and Rad54 promote non-crossover recombination between centromere repeats on the same <span class="hlt">chromatid</span>, thereby suppressing crossover between non-allelic repeats on sister <span class="hlt">chromatids</span> that leads to chromosomal rearrangements. Furthermore, we found that Rad51 and Rad54 are required for gene silencing in centromeres, suggesting that HR also plays a role in the structure and function of centromeres. PMID:27697832</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('https://www.osti.gov/scitech/biblio/22162960','SCIGOV-STC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/26542736','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26542736"><span id="translatedtitle">Guanine nucleotide <span class="hlt">induced</span> conformational change of Cdc42 revealed by hydrogen/deuterium <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>Yang, Sheng-Wei; Ting, Hsiu-Chi; Lo, Yi-Ting; Wu, Ting-Yuan; Huang, Hung-Wei; Yang, Chia-Jung; Chan, Jui-Fen Riva; Chuang, Min-Chieh; Hsu, Yuan-Hao Howard</p> <p>2016-01-01</p> <p>Cdc42 regulates pathways related to cell division. Dysregulation of Cdc42 can lead to cancer, cardiovascular diseases and neurodegenerative diseases. GTP <span class="hlt">induced</span> activation mechanism plays an important role in the activity and biological functions of Cdc42. P-loop, Switch I and Switch II are critical regions modulating the enzymatic activity of Cdc42. We applied amide hydrogen/deuterium <span class="hlt">exchange</span> coupled with liquid chromatography mass spectrometry (HDXMS) to investigate the dynamic changes of apo-Cdc42 after GDP, GTP and GMP-PCP binding. The natural substrate GTP <span class="hlt">induced</span> significant decreases of deuteration in P-loop and Switch II, moderate changes of deuteration in Switch I and significant changes of deuteration in the α7 helix, a region far away from the active site. GTP binding <span class="hlt">induced</span> similar effects on H/D <span class="hlt">exchange</span> to its non-hydrolysable analog, GMP-PCP. HDXMS results indicate that GTP binding blocked the solvent accessibility in the active site leading to the decrease of H/D <span class="hlt">exchange</span> rate surrounding the active site, and further triggered a conformational change resulting in the drastic decrease of H/D <span class="hlt">exchange</span> rate at the remote α7 helix. Comparing the deuteration levels in three activation states of apo-Cdc42, Cdc42-GDP and Cdc42-GMP-PCP, the apo-Cdc42 has the most flexible structure, which can be stabilized by guanine nucleotide binding. The rates of H/D <span class="hlt">exchange</span> of Cdc42-GDP are between the GMP-PCP-bound and the apo form, but more closely to the GMP-PCP-bound form. Our results show that the activation of Cdc42 is a process of conformational changes involved with P-loop, Switch II and α7 helix for structural stabilization.</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('http://adsabs.harvard.edu/abs/2016PhRvB..94v0408T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94v0408T"><span id="translatedtitle">Stoner versus Heisenberg: Ultrafast <span class="hlt">exchange</span> reduction and magnon generation during laser-<span class="hlt">induced</span> demagnetization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turgut, Emrah; Zusin, Dmitriy; Legut, Dominik; Carva, Karel; Knut, Ronny; Shaw, Justin M.; Chen, Cong; Tao, Zhensheng; Nembach, Hans T.; Silva, Thomas J.; Mathias, Stefan; Aeschlimann, Martin; Oppeneer, Peter M.; Kapteyn, Henry C.; Murnane, Margaret M.; Grychtol, Patrik</p> <p>2016-12-01</p> <p>Understanding how the electronic band structure of a ferromagnetic material is modified during laser-<span class="hlt">induced</span> demagnetization on femtosecond time scales has been a long-standing question in condensed matter physics. Here, we use ultrafast high harmonics to measure time-, energy-, and angle-resolved M -edge magnetic asymmetry spectra for Co films after optical pumping to <span class="hlt">induce</span> ultrafast demagnetization. This provides a complete data set that we can compare with advanced ab initio magneto-optical calculations. Our analysis identifies that the dominant mechanisms contributing to ultrafast demagnetization on time scales up to several picoseconds are a transient reduction in the <span class="hlt">exchange</span> splitting and the excitation of ultrafast magnons. Surprisingly, we find that the magnon contribution to ultrafast demagnetization is already strong on subpicosecond time scales, while the reduction in <span class="hlt">exchange</span> splitting persists to several picoseconds.</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('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('https://www.ncbi.nlm.nih.gov/pubmed/15955849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15955849"><span id="translatedtitle">Unzipped and loaded: the role of DNA helicases and RFC clamp-loading complexes in 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>Skibbens, Robert V</p> <p>2005-06-20</p> <p>It is well known that the products of chromosome replication are paired to ensure that the sisters segregate away from each other during mitosis. A key issue is how cells pair sister <span class="hlt">chromatids</span> but preclude the catastrophic pairing of nonsister <span class="hlt">chromatids</span>. The identification of both replication factor C and DNA helicases as critical for sister <span class="hlt">chromatid</span> pairing has brought new insights into this fundamental process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..92v0422P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..92v0422P"><span id="translatedtitle">Interfacial <span class="hlt">exchange</span>-coupling <span class="hlt">induced</span> chiral symmetry breaking of spin-orbit effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perna, P.; Ajejas, F.; Maccariello, D.; Fernandez Cuñado, J. L.; Guerrero, R.; Niño, M. A.; Bollero, A.; Miranda, R.; Camarero, J.</p> <p>2015-12-01</p> <p>We demonstrate that the interfacial <span class="hlt">exchange</span> coupling in ferromagnetic/antiferromagnetic (FM/AFM) systems <span class="hlt">induces</span> symmetry breaking of the spin-orbit (SO) effects. This has been done by studying the field and angle dependencies of anisotropic magnetoresistance and vectorial-resolved magnetization hysteresis loops, measured simultaneously and reproduced with numerical simulations. We show how the <span class="hlt">induced</span> unidirectional magnetic anisotropy at the FM/AFM interface results in strong asymmetric transport behaviors, which are chiral around the magnetization hard-axis direction. Similar asymmetric features are anticipated in other SO-driven phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12910308','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12910308"><span id="translatedtitle">Effect of sodium succinate on gas <span class="hlt">exchange</span> in rats with barbiturate-<span class="hlt">induced</span> coma.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shefer, T V; Ivnitskii, Yu Yu; Malakhovskii, V N</p> <p>2003-04-01</p> <p>Injection of sodium succinate in doses of 5 or 10 mmol/kg (but not 1 mmol/kg) intensified oxygen consumption in rats with sodium thiopental-<span class="hlt">induced</span> coma. Injection of SDH inhibitor (sodium malonate) inhibited gas <span class="hlt">exchange</span> and abolished the effect of sodium succinate. The effect of succinate on rat survival was positive, while that of malonate was negative, but manifested only as a trend. The critical role of succinate oxidation in preventing lethal complications of barbiturate-<span class="hlt">induced</span> coma is proved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=coastline&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=89940547&CFTOKEN=25909268','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=coastline&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=89940547&CFTOKEN=25909268"><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/2016PhRvB..94o5441Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94o5441Z"><span id="translatedtitle">Theory of proximity-<span class="hlt">induced</span> <span class="hlt">exchange</span> coupling in graphene on hBN/(Co, Ni)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zollner, Klaus; Gmitra, Martin; Frank, Tobias; Fabian, Jaroslav</p> <p>2016-10-01</p> <p>Graphene, being essentially a surface, can borrow some properties of an insulating substrate (such as <span class="hlt">exchange</span> or spin-orbit couplings) while still preserving a great degree of autonomy of its electronic structure. Such derived properties are commonly labeled as proximity. Here we perform systematic first-principles calculations of the proximity <span class="hlt">exchange</span> coupling, <span class="hlt">induced</span> by cobalt (Co) and nickel (Ni) in graphene, via a few (up to three) layers of hexagonal boron nitride (hBN). We find that the <span class="hlt">induced</span> spin splitting of the graphene bands is of the order of 10 meV for a monolayer of hBN, decreasing in magnitude but alternating in sign by adding each new insulating layer. We find that the proximity <span class="hlt">exchange</span> can be giant if there is a resonant d level of the transition metal close to the Dirac point. Our calculations suggest that this effect could be present in Co heterostructures, in which a d level strongly hybridizes with the valence-band orbitals of graphene. Since this hybridization is spin dependent, the proximity spin splitting is unusually large, about 10 meV even for two layers of hBN. An external electric field can change the offset of the graphene and transition-metal orbitals and can lead to a reversal of the sign of the <span class="hlt">exchange</span> parameter. This we predict to happen for the case of two monolayers of hBN, enabling electrical control of proximity spin polarization (but also spin injection) in graphene/hBN/Co structures. Nickel-based heterostructures show weaker proximity effects than cobalt heterostructures. We introduce two phenomenological models to describe the first-principles data. The minimal model comprises the graphene (effective) pz orbitals and can be used to study transport in graphene with proximity <span class="hlt">exchange</span>, while the pz-d model also includes hybridization with d orbitals, which is important to capture the giant proximity <span class="hlt">exchange</span>. Crucial to both models is the pseudospin-dependent <span class="hlt">exchange</span> coupling, needed to describe the different spin</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3950876','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3950876"><span id="translatedtitle">Guanine nucleotide <span class="hlt">exchange</span> factor Dock7 mediates HGF-<span class="hlt">induced</span> glioblastoma cell invasion via Rac activation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Murray, D W; Didier, S; Chan, A; Paulino, V; Van Aelst, L; Ruggieri, R; Tran, N L; Byrne, A T; Symons, M</p> <p>2014-01-01</p> <p>Background: Glioblastoma multiforme (GBM), a highly invasive primary brain tumour, remains an incurable disease. Rho GTPases and their activators, guanine nucleotide <span class="hlt">exchange</span> factors (GEFs), have central roles in GBM invasion. Anti-angiogenic therapies may stimulate GBM invasion via HGF/c-Met signalling. We aim to identify mediators of HGF-<span class="hlt">induced</span> GBM invasion that may represent targets in a combination anti-angiogenic/anti-invasion therapeutic paradigm. Methods: Guanine nucleotide <span class="hlt">exchange</span> factor expression was measured by microarray analysis and western blotting. Specific depletion of proteins was accomplished using siRNA. Cell invasion was determined using matrigel and brain slice assays. Cell proliferation and survival were monitored using sulforhodamine B and colony formation assays. Guanine nucleotide <span class="hlt">exchange</span> factor and GTPase activities were determined using specific affinity precipitation assays. Results: We found that expression of Dock7, a GEF, is elevated in human GBM tissue in comparison with non-neoplastic brain. We showed that Dock7 mediates serum- and HGF-<span class="hlt">induced</span> glioblastoma cell invasion. We also showed that Dock7 co-immunoprecipitates with c-Met and that this interaction is enhanced upon HGF stimulation in a manner that is dependent on the adaptor protein Gab1. Dock7 and Gab1 also co-immunoprecipitate in an HGF-dependent manner. Furthermore, Gab1 is required for HGF-<span class="hlt">induced</span> Dock7 and Rac1 activation and glioblastoma cell invasion. Conclusions: Dock7 mediates HGF-<span class="hlt">induced</span> GBM invasion. Targeting Dock7 in GBM may inhibit c-MET-mediated invasion in tumours treated with anti-angiogenic regimens. PMID:24518591</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://adsabs.harvard.edu/abs/2008PhRvD..77c4001T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhRvD..77c4001T"><span id="translatedtitle">Photon <span class="hlt">induced</span> Λ(1520) production and the role of the K* <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>Toki, Hiroshi; García-Recio, Carmen; Nieves, Juan</p> <p>2008-02-01</p> <p>We study the photon <span class="hlt">induced</span> Λ(1520) production in the effective Lagrangian method near threshold, EγLAB≤2GeV, and in the quark-gluon string model at higher energies 3GeV≤EγLAB≤5GeV. In particular, we study the role of the K* <span class="hlt">exchange</span> for the production of Λ(1520) within the SU(6) Weinberg-Tomozowa chiral unitary model proposed by García-Recio, Nieves, and Salcedo [Phys. Rev. D 74, 034025 (2006)PRVDAQ0556-282110.1103/PhysRevD.74.034025]. The coupling of the Λ(1520) resonance to the NK¯* pair, which is dynamically generated, turns out to be relatively small and, thus, the K <span class="hlt">exchange</span> mechanism dominates the reaction. In the higher energy region, where experimental data are available, the quark-gluon string mechanism with the K Regge trajectory reproduces both the energy and the angular distribution dependences of the Λ(1520) photoproduction reaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24777198','PUBMED'); return false;" href="https://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>2014-04-29</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>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308052','PMC'); return false;" href="https://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://adsabs.harvard.edu/abs/2016PhRvC..94e4617F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvC..94e4617F"><span id="translatedtitle">Nuclear fragmentation and charge-<span class="hlt">exchange</span> reactions <span class="hlt">induced</span> by pions in the Δ -resonance region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, Zhao-Qing</p> <p>2016-11-01</p> <p>The dynamics of the nuclear fragmentations and the charge <span class="hlt">exchange</span> reactions in pion-nucleus collisions near the Δ (1232) resonance energies has been investigated within the Lanzhou quantum molecular dynamics transport model. An isospin-, momentum-, and density-dependent pion-nucleon potential is implemented in the model, which influences the pion dynamics, in particular the kinetic energy spectra, but weakly impacts the fragmentation mechanism. The absorption process in pion-nucleon collisions to form the Δ (1232) resonance dominates the heating mechanism of the target nucleus. The excitation energy transferred to the target nucleus increases with the pion kinetic energy and is similar for both π-- and π+-<span class="hlt">induced</span> reactions. The magnitude of fragmentation of the target nucleus weakly depends on the pion energy. The isospin ratio in the pion double-charge <span class="hlt">exchange</span> is influenced by the isospin ingredient of target nucleus.</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('http://hdl.handle.net/2060/20110023194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023194"><span id="translatedtitle">The Correlation of Interphase Chromatin Structure with the Radiation-<span class="hlt">Induced</span> Inter- and Intrachromosome <span class="hlt">Exchange</span> Hotspots</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Ye; Mangala, Lingegowda S.; Purgason, Ashley M.; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu</p> <p>2011-01-01</p> <p>To investigate the relationship between chromosome aberrations <span class="hlt">induced</span> by radiation and chromatin folding, we reconstructed three dimensional structure of chromosome 3 and measured the physical distances between different regions of the chromosome. Previously, we have investigated the location of breaks involved in inter- and intrachromosomal type <span class="hlt">exchange</span> events in human chromosome 3, using the multicolor banding in situ hybridization (mBAND) technique. In human epithelial cells exposed to both low- and high-LET radiations in vitro, we reported that intra-chromosome <span class="hlt">exchanges</span> occurred preferentially between a break in the 3p21 and one in the 3q11 regions, and the breaks involving in inter-chromosome <span class="hlt">exchanges</span> occurred in two regions towards the telomeres of the chromosome. <span class="hlt">Exchanges</span> were also observed between a break in 3p21 and one in 3q26, but few <span class="hlt">exchanges</span> were observed between breaks in 3q11 and 3q26, even though the two regions are located on the same arm of the chromosome. In this study, human epithelial cells were fixed at G1 phase and the interphase cells were hybridized using the XCyte3 mBAND kit from MetaSystems. The z-section images of chromosome 3 were captured with a Leica and an LSM 510 Meta laser scanning confocal microscopes. A total of 100 chromosomes were analyzed. The reconstruction of three dimensional structure of interphase chromosome 3 with six different colored regions was achieved using the Imaris software. The relative distance between different regions was measured as well. We further analyzed fragile sites on the chromosome that have been identified in various types of cancers. The data showed that, in majority of the cells, the regions containing 3p21 and 3q11 are colocalized in the center of the chromosome, whereas, the regions towards the telomeres of the chromosome are either physically wrapping outside the chromosome center or with arms sticking out. Our results demonstrated that the distribution of breaks involved in radiation-<span class="hlt">induced</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19881311','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19881311"><span id="translatedtitle">Involvement of Na+/Ca2+ <span class="hlt">exchanger</span> in pentylenetetrazol-<span class="hlt">induced</span> convulsion by use of Na+/Ca2+ <span class="hlt">exchanger</span> knockout mice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saito, Ryo; Kaneko, Erina; Tanaka, Yusuke; Honda, Kenji; Matsuda, Toshio; Baba, Akemichi; Komuro, Issei; Kita, Satomi; Iwamoto, Takahiro; Takano, Yukio</p> <p>2009-11-01</p> <p>Involvement of Na+/Ca2+ <span class="hlt">exchanger</span> (NCX) in pentylenetetrazol (PTZ)-<span class="hlt">induced</span> convulsion by use of NCX knockout mice and the selective ligand SEA0400 to NCX was examined. In the SEA0400-administered group, the latency to clonic convulsion was extended into 210 s, although the latency to clonic convulsion was observed until 100 s in control group. SEA0400 had little effect on bicuculline-<span class="hlt">induced</span> clonic seizure nicotine-<span class="hlt">induced</span> wild running and 4-aminopyridine-<span class="hlt">induced</span> tonic flexion, respectively. Tonic flexion convulsion was occurred three fifth in the wild type mice group by administration of PTZ, but tonic flexion was not observed in NCX1 knockout mice groups. These results suggest that NCX is involved in inhibitory action in PTZ-<span class="hlt">induced</span> convulsion.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2215085','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2215085"><span id="translatedtitle"><span class="hlt">Exchange</span> diffusion of dopamine <span class="hlt">induced</span> in planar lipid bilayer membranes by the ionophore X537A</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Holz, RW</p> <p>1977-01-01</p> <p>The ionophore X537A causes a large increase in the [(14)C]dopamine (a catecholamine) permeability of planar bilayer membranes. Dopamine transport increases linearly with the ionophore concentration. At relatively high concentrations in the presence of dopamine, the ionophore omdices a conductance which is nearly ideally selective for the dopamine cation. However, the total dopamine flux as determined in tracer experiments is not affected by an electric field and is over 10(5) times larger than predicted from the estimated dopamine conductance. Increasing the dopamine concentration on the side containing radioactive dopamine (the cis side) saturates the dopamine transport. This saturation is relieved by trans addition of nonradioactive dopamine, tyramine, H(+), or K(+). With unequal concentrations of dopamine cis and trans (49 and 12.5 mM), the unidirectional dopamine fluxes are equal. Increasing H(+) cis and trans decreases dopamine transport. It is concluded that at physiological pH, the X537A-<span class="hlt">induced</span> transport of dopamine occurs via an electrically silent <span class="hlt">exchange</span> diffusion of dopamine cation with another cation (e.g., dopamine(+), H(+), or K(+)). X537A <span class="hlt">induces</span> a Ca(++)-independent release of catecholamines from sympathetic nerves by interfering with intracellular storage within storage vesicles (R.W. Holz. 1975. Biochim. Biophys. Acta. 375:138-152). It is suggested that X537A causes an <span class="hlt">exchange</span> of intravesicular catecholamine with a cytoplasmic cation (perhaps K(+) or H(+)) across the storage vesicle membrane. PMID:16982</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://www.dtic.mil/docs/citations/ADA157372','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA157372"><span id="translatedtitle">Application of Sister <span class="hlt">Chromatid</span> <span class="hlt">Exchange</span> in Marine Polychaetes to Black Rock Harbor Sediment. Laboratory Documentation Phase.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1985-01-01</p> <p>Continue on reverse eide if necomeay and Identify by block number) Marine pollution --Genetic effects (LC) Polychaeta (LC) Dredged material (WES) Biological...necessary end Identify by block number) Marine pollution --Genetic effects (LC) Polychaeta (LC) Dredged material (WES) Biological assay (LC) Sister...populations of marine organisms. 2. The importance of genetic effects in marine pollution studies has been recognized only recently. The International Council</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>... the end of the exposure period and blood lymphocyte cell cultures are prepared from study animals... animal lymphocytes are obtained by heart puncture and duplicate cell cultures are started for each animal. Cultures are grown in bromo-deoxyuridine (BrdU), and then a spindle inhibitor (e.g., colchicine) is...</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>... the end of the exposure period and blood lymphocyte cell cultures are prepared from study animals... animal lymphocytes are obtained by heart puncture and duplicate cell cultures are started for each animal. Cultures are grown in bromo-deoxyuridine (BrdU), and then a spindle inhibitor (e.g., colchicine) is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol17/pdf/CFR-2014-title40-vol17-sec79-65.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol17/pdf/CFR-2014-title40-vol17-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=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... to optimize the sample collection time for second division metaphase cells. (ii) This assay may be... added to arrest cell growth in c-metaphase. Cells are harvested 4 hours later and second-division... cells scored. (i) A minimum of 25 well-stained, second-division metaphase cells shall be scored for...</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('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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4139276','PMC'); return false;" href="https://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://adsabs.harvard.edu/abs/2016JGRG..121.2049S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRG..121.2049S"><span id="translatedtitle">Winds <span class="hlt">induce</span> CO2 <span class="hlt">exchange</span> with the atmosphere and vadose zone transport in a karstic ecosystem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez-Cañete, Enrique P.; Oyonarte, Cecilio; Serrano-Ortiz, Penélope; Curiel Yuste, Jorge; Pérez-Priego, Oscar; Domingo, Francisco; Kowalski, Andrew S.</p> <p>2016-08-01</p> <p>Research on the subterranean CO2 dynamics has focused individually on either surface soils or bedrock cavities, neglecting the interaction of both systems as a whole. In this regard, the vadose zone contains CO2-enriched air (ca. 5% by volume) in the first meters, and its <span class="hlt">exchange</span> with the atmosphere can represent from 10 to 90% of total ecosystem CO2 emissions. Despite its importance, to date still lacking are reliable and robust databases of vadose zone CO2 contents that would improve knowledge of seasonal-annual aboveground-belowground CO2 balances. Here we study 2.5 years of vadose zone CO2 dynamics in a semiarid ecosystem. The experimental design includes an integrative approach to continuously measure CO2 in vertical and horizontal soil profiles, following gradients from surface to deep horizons and from areas of net biological CO2 production (under plants) to areas of lowest CO2 production (bare soil), as well as a bedrock borehole representing karst cavities and ecosystem-scale <span class="hlt">exchanges</span>. We found that CO2 followed similar seasonal patterns for the different layers, with the maximum seasonal values of CO2 delayed with depth (deeper more delayed). However, the behavior of CO2 transport differed markedly among layers. Advective transport driven by wind <span class="hlt">induced</span> CO2 emission both in surface soil and bedrock, but with negligible effect on subsurface soil, which appears to act as a buffer impeding rapid CO2 <span class="hlt">exchanges</span>. Our study provides the first evidence of enrichment of CO2 under plant, hypothesizing that CO2-rich air could come from root zone or by transport from deepest layers through cracks and fissures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4292170','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4292170"><span id="translatedtitle">DNA Strand <span class="hlt">Exchange</span> and RecA Homologs in 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>Brown, M. Scott; Bishop, Douglas K.</p> <p>2015-01-01</p> <p>Homology search and DNA strand–<span class="hlt">exchange</span> reactions are central to homologous recombination in meiosis. During meiosis, these processes are regulated such that the probability of choosing a homolog <span class="hlt">chromatid</span> as recombination partner is enhanced relative to that of choosing a sister <span class="hlt">chromatid</span>. This regulatory process occurs as homologous chromosomes pair in preparation for assembly of the synaptonemal complex. Two strand–<span class="hlt">exchange</span> proteins, Rad51 and Dmc1, cooperate in regulated homology search and strand <span class="hlt">exchange</span> in most organisms. Here, we summarize studies on the properties of these two proteins and their accessory factors. In addition, we review current models for the assembly of meiotic strand–<span class="hlt">exchange</span> complexes and the possible mechanisms through which the interhomolog bias of recombination partner choice is achieved. PMID:25475089</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25475089','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25475089"><span id="translatedtitle">DNA strand <span class="hlt">exchange</span> and RecA homologs 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>Brown, M Scott; Bishop, Douglas K</p> <p>2014-12-04</p> <p>Homology search and DNA strand-<span class="hlt">exchange</span> reactions are central to homologous recombination in meiosis. During meiosis, these processes are regulated such that the probability of choosing a homolog <span class="hlt">chromatid</span> as recombination partner is enhanced relative to that of choosing a sister <span class="hlt">chromatid</span>. This regulatory process occurs as homologous chromosomes pair in preparation for assembly of the synaptonemal complex. Two strand-<span class="hlt">exchange</span> proteins, Rad51 and Dmc1, cooperate in regulated homology search and strand <span class="hlt">exchange</span> in most organisms. Here, we summarize studies on the properties of these two proteins and their accessory factors. In addition, we review current models for the assembly of meiotic strand-<span class="hlt">exchange</span> complexes and the possible mechanisms through which the interhomolog bias of recombination partner choice is achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26302862','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26302862"><span id="translatedtitle">Solvent <span class="hlt">exchange-induced</span> in situ forming gel comprising ethyl cellulose-antimicrobial drugs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Phaechamud, Thawatchai; Mahadlek, Jongjan</p> <p>2015-10-15</p> <p>Solvent-<span class="hlt">exchanged</span> in situ forming gel is a drug delivery system which is in sol form before administration. When it contacts with the body fluid, then the water miscible organic solvent dissipates and water penetrates into the system, leading the polymer precipitation as in situ gel at the site of injection. The aim of this research was to study the parameters affecting the gel properties, drug release and antimicrobial activities of the in situ forming gels prepared from ethyl cellulose (EC) dissolved in N-methyl pyrrolidone (NMP) to deliver the antimicrobial agents (doxycycline hyclate, metronidazole and benzyl peroxide) for periodontitis treatment. The gel appearance, pH, viscosity, rheology, syringeability, gel formation, rate of water diffusion into the gels, in vitro degradation, drug release behavior and antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans and Porphyrommonas gingivalis were determined. Increasing the amount of EC increased the viscosity of system while still exhibiting Newtonian flow and increased the work of syringeability whereas decreased the releasing of drug. The system transformed into the rigid gel formation after being injected into the simulated gingival crevicular fluid. The developed systems containing 5% w/w antimicrobial agent showed the antimicrobial activities against all test bacteria. Thus the developed solvent <span class="hlt">exchange-induced</span> in situ forming gels comprising EC-antimicrobial drugs exhibited potential use for periodontitis treatment.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4290709','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4290709"><span id="translatedtitle">Selective Na+/Ca2+ <span class="hlt">exchanger</span> inhibition prevents Ca2+ overload-<span class="hlt">induced</span> triggered arrhythmias</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nagy, Norbert; Kormos, Anita; Kohajda, Zsófia; Szebeni, Áron; Szepesi, Judit; Pollesello, Piero; Levijoki, Jouko; Acsai, Károly; Virág, László; Nánási, Péter P; Papp, Julius Gy; Varró, András; Tóth, András</p> <p>2014-01-01</p> <p>Background and Purpose Augmented Na+/Ca2+ <span class="hlt">exchanger</span> (NCX) activity may play a crucial role in cardiac arrhythmogenesis; however, data regarding the anti-arrhythmic efficacy of NCX inhibition are debatable. Feasible explanations could be the unsatisfactory selectivity of NCX inhibitors and/or the dependence of the experimental model on the degree of Ca2+i overload. Hence, we used NCX inhibitors SEA0400 and the more selective ORM10103 to evaluate the efficacy of NCX inhibition against arrhythmogenic Ca2+i rise in conditions when [Ca2+]i was augmented via activation of the late sodium current (INaL) or inhibition of the Na+/K+ pump. Experimental Approach Action potentials (APs) were recorded from canine papillary muscles and Purkinje fibres by microelectrodes. NCX current (INCX) was determined in ventricular cardiomyocytes utilizing the whole-cell patch clamp technique. Ca2+i transients (CaTs) were monitored with a Ca2+-sensitive fluorescent dye, Fluo-4. Key Results Enhanced INaL increased the Ca2+ load and AP duration (APD). SEA0400 and ORM10103 suppressed INCX and prevented/reversed the anemone toxin II (ATX-II)-<span class="hlt">induced</span> [Ca2+]i rise without influencing APD, CaT or cell shortening, or affecting the ATX-II-<span class="hlt">induced</span> increased APD. ORM10103 significantly decreased the number of strophanthidin-<span class="hlt">induced</span> spontaneous diastolic Ca2+ release events; however, SEA0400 failed to restrict the veratridine-<span class="hlt">induced</span> augmentation in Purkinje-ventricle APD dispersion. Conclusions and Implications Selective NCX inhibition – presumably by blocking revINCX (reverse mode NCX current) – is effective against arrhythmogenesis caused by [Na+]i-<span class="hlt">induced</span> [Ca2+]i elevation, without influencing the AP waveform. Therefore, selective INCX inhibition, by significantly reducing the arrhythmogenic trigger activity caused by the perturbed Ca2+i handling, should be considered as a promising anti-arrhythmic therapeutic strategy. PMID:25073832</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=giemsa&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgiemsa','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=giemsa&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgiemsa"><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.ncbi.nlm.nih.gov/pubmed/23003184','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23003184"><span id="translatedtitle">Effect of interface-<span class="hlt">induced</span> <span class="hlt">exchange</span> fields on cuprate-manganite spin switches.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Yaohua; Visani, C; Nemes, N M; Fitzsimmons, M R; Zhu, L Y; Tornos, J; Garcia-Hernandez, M; Zhernenkov, M; Hoffmann, A; Leon, C; Santamaria, J; te Velthuis, S G E</p> <p>2012-05-18</p> <p>We examine the anomalous inverse spin switch behavior in La0.7Ca0.3MnO3(LCMO)/YBa2Cu3O7-δ (YBCO)/LCMO trilayers by combined transport studies and polarized neutron reflectometry. Measuring magnetization profiles and magnetoresistance in an in-plane rotating magnetic field, we prove that, contrary to many accepted theoretical scenarios, the relative orientation between the two LCMO's magnetizations is not sufficient to determine the magnetoresistance. Rather the field dependence of magnetoresistance is explained by the interplay between the applied magnetic field and the (exponential tail of the) <span class="hlt">induced</span> <span class="hlt">exchange</span> field in YBCO, the latter originating from the electronic reconstruction at the LCMO/YBCO interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11727979','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11727979"><span id="translatedtitle">Improved TROSY-HNCA experiment with suppression of conformational <span class="hlt">exchange</span> <span class="hlt">induced</span> relaxation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pervushin, K; Gallius, V; Ritter, C</p> <p>2001-10-01</p> <p>A general method for improving of the sensitivity of the TROSY-type triple resonance experiments in the presence of conformational <span class="hlt">exchange-induced</span> (CSX) relaxation is proposed based on the use of CPMG-INEPT (Müller et al., J. Am. Chem. Soc., 1995, 117, 11043-11048) during the N-C polarization transfer periods. Significantly improved sensitivity is demonstrated for the majority of cross-peaks in the new [15N,1H]-TROSY-XY-HNCA experiment, measured with partially folded RNase AS-Protein, with negligible loss of sensitivity for resonances unaffected by CSX relaxation. In addition, a comparison of cross-peak amplitudes in [15N,1N]-TROSY-XY-HNCA and conventional [15N,1H]-TROSY-HNCA spectra provides a quick and sensitive estimation of the CSX relaxation contribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24054226','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24054226"><span id="translatedtitle">Konjac glucomannan-<span class="hlt">induced</span> changes in thiol/disulphide <span class="hlt">exchange</span> and gluten conformation upon dough mixing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Yun; Zhao, Dan; Foster, Tim J; Liu, Yixin; Wang, Yu; Nirasawa, Satoru; Tatsumi, Eizo; Cheng, Yongqiang</p> <p>2014-01-15</p> <p>Effects of konjac glucomannan (KGM) on the changes in gluten upon dough mixing were investigated in this study. Wheat flour was blended with KGM and processed into dough. Farinographic analysis showed that KGM caused a significant increase in water absorption and dough development time to reach maximum consistency. Comparison of electrophoretic protein profile from control dough and KGM-dough revealed that protein fractions were similar in molecular size distribution, but the lability of glutenin aggregates slightly differed. Addition of KGM to gluten <span class="hlt">induced</span> negative effects on <span class="hlt">exchange</span> between sulfhydryl groups and disulphide bonds. Fourier transform-Raman spectroscopy indicated that secondary structure of gluten proteins was differentially modified related with water absorption of flours before dough formation. This study reveals that when KGM is added to the dough, conformational behaviours of gluten proteins are changed and the hydroxyl groups of KGM might be involved in the interaction by forming strong intermolecular hydrogen bonding system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27181112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27181112"><span id="translatedtitle">Transformation from Globular to Cylindrical Mixed Micelles through Molecular <span class="hlt">Exchange</span> that <span class="hlt">Induces</span> Micelle Fusion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jensen, Grethe V; Lund, Reidar; Narayanan, Theyencheri; Pedersen, Jan Skov</p> <p>2016-06-02</p> <p>Transformations between different micellar morphologies in solution <span class="hlt">induced</span> by changes in composition, salt, or temperature are well-known phenomena; however, the understanding of the associated kinetic pathways is still limited. Especially for mixed surfactant systems, the micelles can take a very wide range of structures, depending on the surfactant packing parameter and other thermodynamic conditions. Synchrotron-based small-angle X-ray scattering (SAXS) in combination with fast mixing using a stopped-flow apparatus can give direct access to the structural kinetics on a millisecond time scale. Here, this approach is used to study the formation of cylindrical micelles after mixing two solutions with globular micelles of the nonionic surfactant dodecyl maltoside (DDM) and the anionic surfactant sodium dodecyl sulfate (SDS), respectively. Two separate processes were identified: (i) a transition in micellar shell structure, interpreted as <span class="hlt">exchange</span> of surfactant molecules resulting in mixed globular micelles, and subsequently, (ii) fusion into larger, cylindrical structures.</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('http://adsabs.harvard.edu/abs/2010ApPhL..97h2104H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..97h2104H"><span id="translatedtitle">Interface-controlled layer <span class="hlt">exchange</span> in metal-<span class="hlt">induced</span> crystallization of germanium thin films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Shu; Marshall, Ann F.; McIntyre, Paul C.</p> <p>2010-08-01</p> <p>Low-temperature synthesis of polycrystalline germanium (poly-Ge) thin films is of great interest in thin-film photovoltaic and electronics applications. We demonstrate metal (Al)-<span class="hlt">induced</span> crystallization to form poly-Ge thin films on both glass and polymer substrates at temperatures as low as 200 °C. An interfacial diffusion control layer, intentionally interposed between the Al and the underlying amorphous Ge (a-Ge) layer, is found to achieve layer <span class="hlt">exchange</span> while suppressing uncontrolled Ge crystallization within the bilayer samples. Germanium thin films with micron-size grains and (111)-preferred orientation are prepared by controlled Ge nucleation and Ge lateral overgrowth of Al during a-Ge crystallization.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4057850','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4057850"><span id="translatedtitle">Tempol protects human lymphocytes from genotoxicity <span class="hlt">induced</span> by cisplatin</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Khabour, Omar F; Alzoubi, Karem H; Mfady, Doa’a S; Alasseiri, Mohammed; Hasheesh, Taghrid F</p> <p>2014-01-01</p> <p>The use of cisplatin in treatments of human malignancies is limited by its side effects that include DNA damage and the subsequent risk of developing secondary cancer. In this study, we examined the possible protective effect of Tempol against DNA damage <span class="hlt">induced</span> by cisplatin in human lymphocytes using chromosomal aberrations (CAs) and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) assays. Cisplatin <span class="hlt">induced</span> significant elevation in the frequencies of CAs and SCEs in cultured human lymphocytes (P < 0.01). Treatment of lymphocytes with Tempol significantly lowered CAs and SCEs <span class="hlt">induced</span> by cisplatin. Tempol alone did not affect spontaneous levels of SCEs and CAs observed in the control group (P > 0.05). In conclusion, Tempol protects human lymphocytes against genotoxicity <span class="hlt">induced</span> by the anticancer drug cisplatin. PMID:24955171</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22939911','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22939911"><span id="translatedtitle">Investigation on the artificial <span class="hlt">exchange</span> signals <span class="hlt">induced</span> by the RIDER effect in CODEX experiments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Rongchun; Chen, Tiehong; Sun, Pingchuan; Li, Baohui; Ding, Datong</p> <p>2012-01-01</p> <p>The CODEX (center-band only detection of <span class="hlt">exchange</span>) NMR experiment is widely used for the detection of slow motions in organic solids, especially polymers. However, the RIDER (relaxation-<span class="hlt">induced</span> dipolar <span class="hlt">exchange</span> with recoupling) effect may result in artificial <span class="hlt">exchange</span> signals in the CODEX pure <span class="hlt">exchange</span> spectrum, which greatly limits the application of CODEX method. Herein, we investigate the distance range that the RIDER effect can reach by performing CODEX experiments on two typical organic solids, hexadecyltrimethylammonium bromide (CTAB) and semi-crystalline polyamide-6 (PA6) where there are no slow molecular motions at room temperature. Our experimental results demonstrate that generally two-bond distance is far enough to ignore the RIDER effect resulted from the dipolar interactions between (13)C and the fast relaxing heteronucleus (14)N. From the built-up curve of RIDER signals as a function of recoupling time and mixing time, it is clearly revealed that the RIDER effect can greatly affect the signal from (13)C directly bonded with (14)N. However, this RIDER effect accounts less than 3% of the reference intensity for signals from (13)C not directly bonded with (14)N if typical recoupling (~0.5 ms) and mixing times (~0.5 s) are used for the investigation of slow motions. When longer recoupling and mixing time are used, there are small RIDER signals even for the (13)C far away from the (14)N. These signals, to a large degree, result from the spin diffusion effect and/or the special microscopic molecule arrangement. However, they are so small compared to the reference signal (~5%) that they can be ignored. Finally, according to the simulation results, it is worth noting that the RIDER signal is still generally negligible compared to the signals due to slow motions if the chemical shift anisotropy reorientation during the mixing time is not too small(larger than 20°) under the condition of 4t(r) recoupling time at the magic-angle-spinning speed of 6.5 kHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NuPhA.828...29B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NuPhA.828...29B"><span id="translatedtitle"><span class="hlt">Exchange</span> terms in the two-nucleon <span class="hlt">induced</span> non-mesonic weak decay of Λ-hypernuclei</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauer, E.; Garbarino, G.</p> <p>2009-09-01</p> <p>The contribution of Pauli <span class="hlt">exchange</span> terms to the two-nucleon <span class="hlt">induced</span> non-mesonic weak decay of CΛ12 hypernuclei, ΛNN→nNN ( N=n or p), is studied within a nuclear matter formalism implemented in a local density approximation. We have adopted a weak transition potential including the <span class="hlt">exchange</span> of the complete octets of pseudoscalar and vector mesons as well as a residual strong interaction modeled on the Bonn potential. Among the <span class="hlt">exchange</span> contributions, only the dominant ones have been evaluated microscopically from the corresponding Goldstone diagrams; a Landau-Migdal model has been adopted for the remaining <span class="hlt">exchange</span> terms. The introduction of <span class="hlt">exchange</span> terms turns out to reduce the two-nucleon <span class="hlt">induced</span> non-mesonic rate by 18% and, jointly with an increase in the one-nucleon <span class="hlt">induced</span> rate by the same magnitude, reveals to be significant for an accurate determination of the full set of hypernuclear non-mesonic decay widths in theoretical and experimental analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1066175','PMC'); return false;" href="https://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('https://www.osti.gov/scitech/biblio/7082480','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7082480"><span id="translatedtitle">Measurement of a hyperfine-<span class="hlt">induced</span> spin-<span class="hlt">exchange</span> frequency shift in atomic hydrogen</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Walsworth, R.L.; Silvera, I.F. ); Mattison, E.M.; Vessot, R.F.C. )</p> <p>1992-09-01</p> <p>We have measured a hyperfine-<span class="hlt">induced</span> spin-<span class="hlt">exchange</span> frequency shift in the atomic-hydrogen ground-state hyperfine transition. A recent quantum-mechanical treatment of low-energy hydrogen-hydrogen scattering by Koelman {ital et} {ital al}. (Phys. Rev. A 38, 3535 (1988)) predicts such frequency shifts to become large at low temperature, and to affect the performance of atomic clocks such as the cryogenic hydrogen maser. The experiment reported here was performed with a hydrogen maser operating near room temperature, where the reported hyperfine effects are predicted to be small, but measurable. Using an adiabatic fast passage (AFP) technique to vary the incoming atomic population in the masing states from approximately 100% (AFP on) to 50% (AFP off), we determined the change in the dimensionless hyperfine-<span class="hlt">induced</span> frequency-shift parameter {Omega} to be {Omega}{sub on}{minus}{Omega}{sub off}=5.38 (1.06){times}10{sup {minus}4}. The theoretical prediction at this temperature is {Omega}{sub on}{minus}{Omega}{sub off}={minus}0.76{times}10{sup {minus}4} to {minus}1.12{times}10{sup {minus}4}, for the range of masing-state populations used in the present experiment. We review the relevant theory, report our experimental method and results, and discuss possible reasons for the discrepancy between experiment and theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1592785','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1592785"><span id="translatedtitle">Bloom Helicase and DNA Topoisomerase IIIα Are Involved in the Dissolution of 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>Seki, Masayuki; Nakagawa, Takayuki; Seki, Takahiko; Kato, Genta; Tada, Shusuke; Takahashi, Yuriko; Yoshimura, Akari; Kobayashi, Takayuki; Aoki, Ayako; Otsuki, Makoto; Habermann, Felix A.; Tanabe, Hideyuki; Ishii, Yutaka; Enomoto, Takemi</p> <p>2006-01-01</p> <p>Bloom's syndrome (BS) is an autosomal disorder characterized by predisposition to a wide variety of cancers. The gene product whose mutation leads to BS is the RecQ family helicase BLM, which forms a complex with DNA topoisomerase IIIα (Top3α). However, the physiological relevance of the interaction between BLM and Top3α within the cell remains unclear. We show here that Top3α depletion causes accumulation of cells in G2 phase, enlargement of nuclei, and chromosome gaps and breaks that occur at the same position in sister <span class="hlt">chromatids</span>. The transition from metaphase to anaphase is also inhibited. All of these phenomena except cell lethality are suppressed by BLM gene disruption. Taken together with the biochemical properties of BLM and Top3α, these data indicate that BLM and Top3α execute the dissolution of sister <span class="hlt">chromatids</span>. PMID:16880537</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16851094','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16851094"><span id="translatedtitle">Theoretical rate constants of super-<span class="hlt">exchange</span> hole transfer and thermally <span class="hlt">induced</span> hopping in DNA.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shimazaki, Tomomi; Asai, Yoshihiro; Yamashita, Koichi</p> <p>2005-01-27</p> <p>Recently, the electronic properties of DNA have been extensively studied, because its conductivity is important not only to the study of fundamental biological problems, but also in the development of molecular-sized electronics and biosensors. We have studied theoretically the reorganization energies, the activation energies, the electronic coupling matrix elements, and the rate constants of hole transfer in B-form double-helix DNA in water. To accommodate the effects of DNA nuclear motions, a subset of reaction coordinates for hole transfer was extracted from classical molecular dynamics (MD) trajectories of DNA in water and then used for ab initio quantum chemical calculations of electron coupling constants based on the generalized Mulliken-Hush model. A molecular mechanics (MM) method was used to determine the nuclear Franck-Condon factor. The rate constants for two types of mechanisms of hole transfer-the thermally <span class="hlt">induced</span> hopping (TIH) and the super-<span class="hlt">exchange</span> mechanisms-were determined based on Marcus theory. We found that the calculated matrix elements are strongly dependent on the conformations of the nucleobase pairs of hole-transferable DNA and extend over a wide range of values for the "rise" base-step parameter but cluster around a particular value for the "twist" parameter. The calculated activation energies are in good agreement with experimental results. Whereas the rate constant for the TIH mechanism is not dependent on the number of A-T nucleobase pairs that act as a bridge, the rate constant for the super-<span class="hlt">exchange</span> process rapidly decreases when the length of the bridge increases. These characteristic trends in the calculated rate constants effectively reproduce those in the experimental data of Giese et al. [Nature 2001, 412, 318]. The calculated rate constants were also compared with the experimental results of Lewis et al. [Nature 2000, 406, 51].</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.ncbi.nlm.nih.gov/pubmed/27422821','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27422821"><span id="translatedtitle">Opposing Functions of the N-terminal Acetyltransferases Naa50 and NatA in 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>Rong, Ziye; Ouyang, Zhuqing; Magin, Robert S; Marmorstein, Ronen; Yu, Hongtao</p> <p>2016-09-02</p> <p>During the cell cycle, sister-<span class="hlt">chromatid</span> cohesion tethers sister <span class="hlt">chromatids</span> together from S phase to the metaphase-anaphase transition and ensures accurate segregation of <span class="hlt">chromatids</span> into daughter cells. N-terminal acetylation is one of the most prevalent protein covalent modifications in eukaryotes and is mediated by a family of N-terminal acetyltransferases (NAT). Naa50 (also called San) has previously been shown to play a role in sister-<span class="hlt">chromatid</span> cohesion in metazoans. The mechanism by which Naa50 contributes to cohesion is not understood however. Here, we show that depletion of Naa50 in HeLa cells weakens the interaction between cohesin and its positive regulator sororin and causes cohesion defects in S phase, consistent with a role of Naa50 in cohesion establishment. Strikingly, co-depletion of NatA, a heterodimeric NAT complex that physically interacts with Naa50, rescues the sister-<span class="hlt">chromatid</span> cohesion defects and the resulting mitotic arrest caused by Naa50 depletion, indicating that NatA and Naa50 play antagonistic roles in cohesion. Purified recombinant NatA and Naa50 do not affect each other's NAT activity in vitro Because NatA and Naa50 exhibit distinct substrate specificity, we propose that they modify different effectors and regulate sister-<span class="hlt">chromatid</span> cohesion in opposing ways.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4593829','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4593829"><span id="translatedtitle">Role of the Na+/H+ <span class="hlt">exchanger</span> 3 in angiotensin II-<span class="hlt">induced</span> hypertension</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</p> <p>2015-01-01</p> <p>The renal mechanisms responsible for angiotensin II (ANG II)-<span class="hlt">induced</span> hypertension remain incompletely understood. The present study tested the hypothesis that the Na+/H+ <span class="hlt">exchanger</span> 3 (NHE3) is required for ANG II-<span class="hlt">induced</span> hypertension in mice. Five groups of wild-type (Nhe3+/+) and Nhe3−/− mice were treated with vehicle or high pressor doses of ANG II (1.5 mg/kg/day ip, via minipump for 2 wk, or 10 pmol/min iv for 30 min). Under basal conditions, Nhe3−/− mice had significantly lower systolic blood pressure (SBP) and mean intra-arterial pressure (MAP) (P < 0.01), 24 h urine (P < 0.05), urinary Na+ (P < 0.01) and urinary K+ excretion (P < 0.01). In response to ANG II, SBP and MAP markedly increased in Nhe3+/+ mice in a time-dependent manner, as expected (P < 0.01). However, these acute and chronic pressor responses to ANG II were significantly attenuated in Nhe3−/− mice (P < 0.01). Losartan blocked ANG II-<span class="hlt">induced</span> hypertension in Nhe3+/+ mice but <span class="hlt">induced</span> marked mortality in Nhe3−/− mice. The attenuated pressor responses to ANG II in Nhe3−/− mice were associated with marked compensatory humoral and renal responses to genetic loss of intestinal and renal NHE3. These include elevated basal plasma ANG II and aldosterone and kidney ANG II levels, salt wasting from the intestines, increased renal AQP1, Na+/HCO3−, and Na+/K+-ATPase expression, and increased PKCα, mitogen-activated protein kinases ERK1/2, and glycogen synthase kinase 3αβ signaling proteins in the proximal tubules (P < 0.01). We concluded that NHE3 in proximal tubules of the kidney, along with NHE3 in intestines, is required for maintaining basal blood pressure as well as the full development of ANG II-<span class="hlt">induced</span> hypertension. PMID:26242933</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.ncbi.nlm.nih.gov/pubmed/25257310','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25257310"><span id="translatedtitle">Functional genomics identifies a requirement of pre-mRNA splicing factors for 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>Sundaramoorthy, Sriramkumar; Vázquez-Novelle, María Dolores; Lekomtsev, Sergey; Howell, Michael; Petronczki, Mark</p> <p>2014-11-18</p> <p>Sister <span class="hlt">chromatid</span> cohesion mediated by the cohesin complex is essential for chromosome segregation during cell division. Using functional genomic screening, we identify a set of 26 pre-mRNA splicing factors that are required for sister <span class="hlt">chromatid</span> cohesion in human cells. Loss of spliceosome subunits increases the dissociation rate of cohesin from chromatin and abrogates cohesion after DNA replication, ultimately causing mitotic catastrophe. Depletion of splicing factors causes defective processing of the pre-mRNA encoding sororin, a factor required for the stable association of cohesin with chromatin, and an associated reduction of sororin protein level. Expression of an intronless version of sororin and depletion of the cohesin release protein WAPL suppress the cohesion defect in cells lacking splicing factors. We propose that spliceosome components contribute to sister <span class="hlt">chromatid</span> cohesion and mitotic chromosome segregation through splicing of sororin pre-mRNA. Our results highlight the loss of cohesion as an early cellular consequence of compromised splicing. This may have clinical implications because SF3B1, a splicing factor that we identify to be essential for cohesion, is recurrently mutated in chronic lymphocytic leukaemia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.110c3108M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.110c3108M"><span id="translatedtitle">Direct synthesis of multilayer graphene on an insulator by Ni-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> growth of amorphous carbon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murata, H.; Toko, K.; Saitoh, N.; Yoshizawa, N.; Suemasu, T.</p> <p>2017-01-01</p> <p>Multilayer graphene (MLG) growth on arbitrary substrates is desired for incorporating carbon wiring and heat spreaders into electronic devices. We investigated the metal-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> growth of a sputtered amorphous C layer using Ni as a catalyst. A MLG layer uniformly formed on a SiO2 substrate at 600 °C by layer <span class="hlt">exchange</span> between the C and Ni layers. Raman spectroscopy and electron microscopy showed that the resulting MLG layer was highly oriented and contained relatively few defects. The present investigation will pave the way for advanced electronic devices integrated with carbon materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28254883','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28254883"><span id="translatedtitle">Neuronal hyperactivity causes Na(+)/H(+) <span class="hlt">exchanger-induced</span> extracellular acidification at active synapses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chiacchiaretta, Martina; Latifi, Shahrzad; Bramini, Mattia; Fadda, Manuela; Fassio, Anna; Benfenati, Fabio; Cesca, Fabrizia</p> <p>2017-03-02</p> <p>Extracellular pH impacts on neuronal activity, which is in turn an important determinant of extracellular H(+) concentration. The aim of this study is to describe the spatio-temporal dynamics of extracellular pH at synaptic sites during neuronal hyperexcitability. To address this issue we created ex.E(2)GFP, a membrane-targeted extracellular ratiometric pH indicator exquisitely sensitive to acidic shifts. By monitoring ex.E(2)GFP fluorescence in real time in primary cortical neurons we were able to quantify pH fluctuations during network hyperexcitability <span class="hlt">induced</span> by convulsant drugs or high frequency electrical stimulation. Sustained hyperactivity caused a pH decrease that was reversible upon silencing of neuronal activity and localized to active synapses. This acidic shift was not attributable to the outflow of synaptic vesicle protons into the cleft nor to the activity of membrane-exposed H(+)-vATPase, but rather to the activity of the Na(+)/H(+)-<span class="hlt">exchanger</span>. Our data demonstrate that extracellular synaptic pH shifts take place during epileptic-like activity of neural cultures, underlying the strict links existing between synaptic activity and synaptic pH. This evidence may contribute to the understanding of the physio-pathological mechanisms associated with hyperexcitability in the epileptic brain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23134723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23134723"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Oost, Kristof; Verstraeten, Gert; Doetterl, Sebastian; Notebaert, Bastiaan; Wiaux, François; Broothaerts, Nils; Six, Johan</p> <p>2012-11-20</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-km(2) 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040088798&hterms=polycyclic+aromatic+hydrocarbons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpolycyclic%2Baromatic%2Bhydrocarbons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088798&hterms=polycyclic+aromatic+hydrocarbons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpolycyclic%2Baromatic%2Bhydrocarbons"><span id="translatedtitle">Deuterium enrichment of polycyclic aromatic hydrocarbons by photochemically <span class="hlt">induced</span> <span class="hlt">exchange</span> with deuterium-rich cosmic ices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sandford, S. A.; Bernstein, M. P.; Allamandola, L. J.; Gillette, J. S.; Zare, R. N.</p> <p>2000-01-01</p> <p>The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly <span class="hlt">exchanges</span> its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. <span class="hlt">Exchange</span> occurs via three different chemical processes: D atom addition, D atom <span class="hlt">exchange</span> at oxidized edge sites, and D atom <span class="hlt">exchange</span> at aromatic edge sites. Observed <span class="hlt">exchange</span> rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These <span class="hlt">exchange</span> mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23729739','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23729739"><span id="translatedtitle">SA1 binds directly to DNA through its unique AT-hook to promote sister <span class="hlt">chromatid</span> cohesion at telomeres.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bisht, Kamlesh K; Daniloski, Zharko; Smith, Susan</p> <p>2013-08-01</p> <p>Sister <span class="hlt">chromatid</span> cohesion relies on cohesin, a complex comprising a tri-partite ring and a peripheral subunit Scc3, which is found as two related isoforms SA1 and SA2 in vertebrates. There is a division of labor between the vertebrate cohesin complexes; SA1-cohesin is required at telomeres and SA2-cohesin at centromeres. Depletion of SA1 has dramatic consequences for telomere function and genome integrity, but the mechanism by which SA1-cohesin mediates cohesion at telomeres is not well understood. Here we dissect the individual contribution of SA1 and the ring subunits to telomere cohesion and show that telomeres rely heavily on SA1 and to a lesser extent on the ring for cohesion. Using chromatin immunoprecipitation we show that SA1 is highly enriched at telomeres, is decreased at mitosis when cohesion is resolved, and is increased when cohesion persists. Overexpression of SA1 alone was sufficient to <span class="hlt">induce</span> cohesion at telomeres, independent of the cohesin ring and dependent on its unique (not found in SA2) N-terminal domain, which we show binds to telomeric DNA through an AT-hook motif. We suggest that a specialized cohesion mechanism may be required to accommodate the high level of DNA replication-associated repair at telomeres.</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> </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://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dchromosome','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dchromosome"><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://adsabs.harvard.edu/abs/2017JPhD...50l5004Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhD...50l5004Y"><span id="translatedtitle"><span class="hlt">Exchange</span> bias <span class="hlt">induced</span> at a Co2FeAl0.5Si0.5/Cr interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, C. N. T.; Vick, A. J.; Inami, N.; Ono, K.; Frost, W.; Hirohata, A.</p> <p>2017-03-01</p> <p>In order to engineer the strength of an <span class="hlt">exchange</span> bias in a cubic Heusler alloy layer, crystalline strain has been <span class="hlt">induced</span> at a ferromagnet/antiferromagnet interface by their lattice mismatch in addition to the conventional interfacial <span class="hlt">exchange</span> coupling between them. Such interfaces have been formed in (Co2FeAl0.5Si0.5(CFAS)/Cr)3 structures grown by ultrahigh vacuum molecular beam epitaxy. The magnetic and structural properties have been characterised to investigate the <span class="hlt">exchange</span> interactions at the CFAS/Cr interfaces. Due to the interfacial lattice mismatch of 1.4%, the maximum offset of 18 Oe in a magnetisation curve has been measured for the case of a CFAS (2 nm)/Cr (0.9 nm) interface at 193 K. The half-metallic property of CFAS has been observed to remain unchanged, which agrees with the theoretical prediction by Culbert et al (2008 J. Appl. Phys. 103 07D707). Such a strain-<span class="hlt">induced</span> <span class="hlt">exchange</span> bias may provide insight of the interfacial interactions and may offer a wide flexibility in spintronic device design.</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('https://www.ncbi.nlm.nih.gov/pubmed/21639986','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21639986"><span id="translatedtitle">The detection of palladium particles in proton <span class="hlt">exchange</span> membrane fuel-cell water by laser-<span class="hlt">induced</span> breakdown spectroscopy (LIBS).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Snyder, Stuart C; Wickun, William G; Mode, Jeremy M; Gurney, Brian D; Michels, Fred G</p> <p>2011-06-01</p> <p>Laser-<span class="hlt">induced</span> breakdown spectroscopy (LIBS) using conditional data analysis was applied to aqueous suspensions of palladium particles in the reformate water of palladium-based proton <span class="hlt">exchange</span> membrane fuel cells. A significant amount of palladium was found in the water, indicating degradation of the fuel-cell cathode catalytic layers. The palladium particle-size detection limit was found to be about 400 nm. Calibration procedures to quantify the palladium concentration are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24824847','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24824847"><span id="translatedtitle">Redox-<span class="hlt">exchange</span> <span class="hlt">induced</span> heterogeneous RuO2-conductive polymer nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gui, Zhe; Duay, Jonathon; Hu, Junkai; Lee, Sang Bok</p> <p>2014-06-28</p> <p>A redox <span class="hlt">exchange</span> mechanism between potassium perruthenate (KRuO4) and the functional groups of selected polymers is used here to <span class="hlt">induce</span> RuO2 into and onto conductive polymer nanowires by simply soaking the polymer nanowire arrays in KRuO4 solution. Conductive polymer nanowire arrays of polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT) were studied in this work. SEM and TEM results show that the RuO2 material was distributed differently in the PPY and PEDOT nanowire matrices. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were used to confirm the dispersion and formation of RuO2 materials in these polymer nanowires. Cyclic voltammetry and galvanostatic charge-discharge experiments were used to characterize their electrochemical performance. RuO2-polymer samples prepared with a 6 min soaking time in 10 mM KRuO4 solution show a high specific capacitance of 371 F g(-1) and 500 F g(-1) for PEDOT-based and PPY-based composite nanowires, respectively. This is attributed to the high exposure area of the conductive RuO2 and the good conductivity of the polymer matrix. This work demonstrates a simple method to synthesize heterogeneous polymer based-materials through the redox reaction between conductive polymers and high oxidation state transition metal oxide ions. Different heterogeneous nanocomposites were obtained depending on the polymer properties, and high energy storage performance of the metal oxides can be achieved within these heterogeneous nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10486307','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10486307"><span id="translatedtitle">Copper effects on ion transport across lamprey erythrocyte membrane: Cl(-)/OH(-) <span class="hlt">exchange</span> <span class="hlt">induced</span> by cuprous ions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bogdanova, A Y; Virkki, L V; Gusev, G P; Nikinmaa, M</p> <p>1999-09-15</p> <p>We studied the effects of prelytic copper concentrations on cell volume, intracellular pH, and ion transport in lamprey erythrocytes. Ion fluxes and pH were measured by radioactive tracer technique, patch clamp, and flame photometry. Prelytic CuSO(4) concentration of 100 microM caused anion-dependent intracellular acidification and increase in Cl(-) influx after 2 min lag-phase. In the presence of ascorbate copper effect was amplified and lag-phase was skipped. Pretreatment of the cells with N-phenyl maleimide abolished copper-<span class="hlt">induced</span> changes completely. Copper treatment caused an increase in Na(+) fluxes in both directions and a net Na(+) uptake. Copper-<span class="hlt">induced</span> Na(+) transport was partially amiloride(MIA)-sensitive representing Na(+)/H(+) <span class="hlt">exchange</span>. The nature of the amiloride-insensitive fraction of copper-activated Na(+) influx remains unknown. Cell swelling after 15 min of copper exposure <span class="hlt">induced</span> regulatory volume decrease response involving KCl extrusion via K(+) and Cl(-) volume-sensitive channels. We suggest that the effects of copper on ion transport fit the following sequence of events: (i) cupric ions are reduced to cuprous state on the membrane surface, (ii) electroneutral pairs CuCl and CuOH mediate chloride/hydroxyl <span class="hlt">exchange</span>, as shown before for trialkyltin, dissipating transmembrane pH gradient, and (iii) changes in intracellular pH result in the activation of the Na(+)/H(+) <span class="hlt">exchange</span> and consecutive volume changes cause the RVD response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22927794','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22927794"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23434280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23434280"><span id="translatedtitle">The PP2A inhibitor I2PP2A is essential for sister <span class="hlt">chromatid</span> segregation in oocyte meiosis II.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chambon, Jean-Philippe; Touati, Sandra A; Berneau, Stéphane; Cladière, Damien; Hebras, Céline; Groeme, Rachel; McDougall, Alex; Wassmann, Katja</p> <p>2013-03-18</p> <p>Haploid gametes are generated through two consecutive meiotic divisions, with the segregation of chromosome pairs in meiosis I and sister <span class="hlt">chromatids</span> in meiosis II. Separase-mediated stepwise removal of cohesion, first from chromosome arms and later from the centromere region, is a prerequisite for maintaining sister <span class="hlt">chromatids</span> together until their separation in meiosis II [1]. In all model organisms, centromeric cohesin is protected from separase-dependent removal in meiosis I through the activity of PP2A-B56 phosphatase, which is recruited to centromeres by shugoshin/MEI-S332 (Sgo) [2-5]. How this protection of centromeric cohesin is removed in meiosis II is not entirely clear; we find that all the PP2A subunits remain colocalized with the cohesin subunit Rec8 at the centromere of metaphase II chromosomes. Here, we show that sister <span class="hlt">chromatid</span> separation in oocytes depends on a PP2A inhibitor, namely I2PP2A. I2PP2A colocalizes with the PP2A enzyme at centromeres at metaphase II, independently of bipolar attachment. When I2PP2A is depleted, sister <span class="hlt">chromatids</span> fail to segregate during meiosis II. Our findings demonstrate that in oocytes I2PP2A is essential for faithful sister <span class="hlt">chromatid</span> segregation by mediating deprotection of centromeric cohesin in meiosis II.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1484498','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1484498"><span id="translatedtitle">Metazoan Scc4 Homologs Link Sister <span class="hlt">Chromatid</span> Cohesion to Cell and Axon Migration Guidance</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Seitan, Vlad C; Banks, Peter; Laval, Steve; Majid, Nazia A; Dorsett, Dale; Rana, Amer; Smith, Jim; Bateman, Alex; Krpic, Sanja; Hostert, Arnd; Rollins, Robert A; Erdjument-Bromage, Hediye; Tempst, Paul; Benard, Claire Y; Hekimi, Siegfried; Newbury, Sarah F</p> <p>2006-01-01</p> <p>Saccharomyces cerevisiae Scc2 binds Scc4 to form an essential complex that loads cohesin onto chromosomes. The prevalence of Scc2 orthologs in eukaryotes emphasizes a conserved role in regulating sister <span class="hlt">chromatid</span> cohesion, but homologs of Scc4 have not hitherto been identified outside certain fungi. Some metazoan orthologs of Scc2 were initially identified as developmental gene regulators, such as Drosophila Nipped-B, a regulator of cut and Ultrabithorax, and delangin, a protein mutant in Cornelia de Lange syndrome. We show that delangin and Nipped-B bind previously unstudied human and fly orthologs of Caenorhabditis elegans MAU-2, a non-axis-specific guidance factor for migrating cells and axons. PSI-BLAST shows that Scc4 is evolutionarily related to metazoan MAU-2 sequences, with the greatest homology evident in a short N-terminal domain, and protein–protein interaction studies map the site of interaction between delangin and human MAU-2 to the N-terminal regions of both proteins. Short interfering RNA knockdown of human MAU-2 in HeLa cells resulted in precocious sister <span class="hlt">chromatid</span> separation and in impaired loading of cohesin onto chromatin, indicating that it is functionally related to Scc4, and RNAi analyses show that MAU-2 regulates chromosome segregation in C. elegans embryos. Using antisense morpholino oligonucleotides to knock down Xenopus tropicalis delangin or MAU-2 in early embryos produced similar patterns of retarded growth and developmental defects. Our data show that sister <span class="hlt">chromatid</span> cohesion in metazoans involves the formation of a complex similar to the Scc2-Scc4 interaction in the budding yeast. The very high degree of sequence conservation between Scc4 homologs in complex metazoans is consistent with increased selection pressure to conserve additional essential functions, such as regulation of cell and axon migration during development. PMID:16802858</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.osti.gov/scitech/biblio/5046839','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5046839"><span id="translatedtitle">Effects of contrast medium on radiation-<span class="hlt">induced</span> chromosome aberrations. [X-ray; /sup 60/Co</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matsubara, S.; Suzuki, S.; Suzuki, H.; Kuwabara, Y.; Okano, T.</p> <p>1982-07-01</p> <p>The effects of contrast material (meglumine iothalamate) on radiation-<span class="hlt">induced</span> chromosome aberrations were investigated in studies on the lymphocytes of patients who had undergone diagnostic radiography and in vitro experiments with diagnostic x rays and /sup 60/Co ..gamma.. rays. Chromosome and chromatic aberrations were found to increase significantly with increasing concentrations of contrast material that were added at irradiation. However, the aberrations were not associated with elevation of the ratio of dicentric and ring chromosomes to the number of cells with unstable chromosome aberrations at the first mitosis. Lymphocytes irradiated in the absence of contrast material did not show an increase in chromosome-type aberrations when the agent was given in increasing concentrations during subsequent incubation, but there were greater numbers of <span class="hlt">chromatid</span> gaps and breaks. When lymphocytes were exposed to 400 R (103.2 mC/kg) of /sup 60/Co ..gamma.. rays, the presence of contrast agent did not increase the yield of dicentric and ring chromosomes, but <span class="hlt">induced</span> a marked delay in cell proliferation, especially in lymphocytes with more heavily damaged chromosomes. In additional examination, the contrast agent itself <span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in lymphocytes.</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.ncbi.nlm.nih.gov/pubmed/23122964','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23122964"><span id="translatedtitle">Cyclin A2 is required for sister <span class="hlt">chromatid</span> segregation, but not separase control, in mouse oocyte meiosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Touati, Sandra A; Cladière, Damien; Lister, Lisa M; Leontiou, Ioanna; Chambon, Jean-Philippe; Rattani, Ahmed; Böttger, Franziska; Stemmann, Olaf; Nasmyth, Kim; Herbert, Mary; Wassmann, Katja</p> <p>2012-11-29</p> <p>In meiosis, two specialized cell divisions allow the separation of paired chromosomes first, then of sister <span class="hlt">chromatids</span>. Separase removes the cohesin complex holding sister <span class="hlt">chromatids</span> together in a stepwise manner from chromosome arms in meiosis I, then from the centromere region in meiosis II. Using mouse oocytes, our study reveals that cyclin A2 promotes entry into meiosis, as well as an additional unexpected role; namely, its requirement for separase-dependent sister <span class="hlt">chromatid</span> separation in meiosis II. Untimely cyclin A2-associated kinase activity in meiosis I leads to precocious sister separation, whereas inhibition of cyclin A2 in meiosis II prevents it. Accordingly, endogenous cyclin A is localized to kinetochores throughout meiosis II, but not in anaphase I. Additionally, we found that cyclin B1, but not cyclin A2, inhibits separase in meiosis I. These findings indicate that separase-dependent cohesin removal is differentially regulated by cyclin B1 and A2 in mammalian meiosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25337657','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25337657"><span id="translatedtitle">Solid-solid phase transformations <span class="hlt">induced</span> through cation <span class="hlt">exchange</span> and strain in 2D heterostructured copper sulfide nanocrystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ha, Don-Hyung; Caldwell, Andrew H; Ward, Matthew J; Honrao, Shreyas; Mathew, Kiran; Hovden, Robert; Koker, Margaret K A; Muller, David A; Hennig, Richard G; Robinson, Richard D</p> <p>2014-12-10</p> <p>We demonstrate dual interface formation in nanocrystals (NCs) through cation <span class="hlt">exchange</span>, creating epitaxial heterostructures within spherical NCs. The thickness of the inner-disk layer can be tuned to form two-dimensional (2D), single atomic layers (<1 nm). During the cation <span class="hlt">exchange</span> reaction from copper sulfide to zinc sulfide (ZnS), we observe a solid-solid phase transformation of the copper sulfide phase in heterostructured NCs. As the cation <span class="hlt">exchange</span> reaction is initiated, Cu ions replaced by Zn ions at the interfaces are accommodated in intrinsic Cu vacancy sites present in the initial roxbyite (Cu1.81S) phase of copper sulfide, <span class="hlt">inducing</span> a full phase transition to djurleite (Cu1.94S)/low chalcocite (Cu2S), a more thermodynamically stable phase than roxbyite. As the reaction proceeds and reduces the size of the copper sulfide layer, the epitaxial strain at the interfaces between copper sulfide and ZnS increases and is maximized for a copper sulfide disk ∼ 5 nm thick. To minimize this strain energy, a second phase transformation occurs back to the roxbyite phase, which shares a similar sulfur sublattice to wurtzite ZnS. The observation of a solid-solid phase transformation in our unique heterostructured NCs provides a new pathway to control desired phases and an insight into the influence of cation <span class="hlt">exchange</span> on nanoscale phase transitions in heterostructured materials.</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.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://adsabs.harvard.edu/abs/2006JPS...161...99L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JPS...161...99L"><span id="translatedtitle">Performance of membrane electrode assemblies based on proton <span class="hlt">exchange</span> membranes prepared by pre-irradiation <span class="hlt">induced</span> grafting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jingye; Matsuura, Akio; Kakigi, Tomoyuki; Miura, Takaharu; Oshima, Akihiro; Washio, Masakazu</p> <p></p> <p>Proton <span class="hlt">exchange</span> membranes (PEMs) were prepared by pre-irradiation <span class="hlt">induced</span> grafting of styrene (S) or styrene/divinylbenzene (S/DVB) into the radiation-crosslinked polytetrafluoroethylene (RX-PTFE) films and then sulfonated. The thicknesses of the obtained PEMs were lower than 20 μm and the ion <span class="hlt">exchange</span> capacity (IEC) values were around 2 meq g -1. The surfaces of the PEMs and carbon electrodes were coated with Nafion ® dispersion, and then membrane electrode assembles (MEAs) were prepared by hot-pressing them together. A MEA based on a Nafion ® 112 membrane was also prepared under same procedure for comparison. The performances of the MEAs in a single cell were tested under different cell temperatures and humidifications. Electrochemical impedance spectra (EIS) were measured with ac frequencies which ranged from 100 kHz to 1 Hz at a dc density of 0.5 A cm -2. The obtained impedance curves in Nyquist representation were semicircular.</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/2012CP....402..105A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CP....402..105A"><span id="translatedtitle">Proton <span class="hlt">exchange</span> in acid-base complexes <span class="hlt">induced</span> by reaction coordinates with heavy atom motions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alavi, Saman; Taghikhani, Mahdi</p> <p>2012-06-01</p> <p>We extend previous work on nitric acid-ammonia and nitric acid-alkylamine complexes to illustrate that proton <span class="hlt">exchange</span> reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid-strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton <span class="hlt">exchange</span> transition states are <400 cm-1. This contrasts with widely studied proton <span class="hlt">exchange</span> reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm-1. Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.106b2407N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.106b2407N"><span id="translatedtitle">Antisite disorder-<span class="hlt">induced</span> <span class="hlt">exchange</span> bias effect in multiferroic Y2CoMnO6</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.; Chatterji, Tapan; Strydom, André M.</p> <p>2015-01-01</p> <p><span class="hlt">Exchange</span> bias effect in the ferromagnetic double perovskite compound Y2CoMnO6, which is also a multiferroic, is reported. The <span class="hlt">exchange</span> bias, observed below 8 K, is explained as arising due to the interface effect between the ferromagnetic and antiferromagnetic clusters created by antisite disorder in this material. Below 8 K, prominent ferromagnetic hysteresis with metamagnetic "steps" and significant coercive field, Hc ≈ 10 kOe are observed in this compound which has a Tc ≈ 75 K. A model based on growth of ferromagnetic domains overcoming the elastic energy of structurally pinned magnetic interfaces, which closely resembles martensitic-like transitions, is adapted to explain the observed effects. The role of antisite disorder in creating the domain structure leading to <span class="hlt">exchange</span> bias effect is highlighted in the present work.</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('https://www.ncbi.nlm.nih.gov/pubmed/3824903','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3824903"><span id="translatedtitle">The use of differential staining of sister <span class="hlt">chromatid</span> to estimate the in vitro effect of human alpha interferon on cell division in normal and tumour cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Georgian, L; Moraru, I; Ghyka, G; Savi, I; Călugăru, A</p> <p>1986-01-01</p> <p>Concentration of 10, 100 and 1000 I.U./ml of human leukocyte alpha interferon (IFN) were added into peripheral human blood (PBL) cultures and in KB cell cultures in the presence of 5-bromdeoxyuridine (BrdU) at 10 micrograms/ml. After 72 hours the differential staining of sister <span class="hlt">chromatid</span> (harlequin) technique was applied in order to differentiate among the metaphases of successive cell generations occurring in the presence of IFN. The frequency of the first (M1), second (M2) and third (M3) metaphases was recorded and the replication index (RI) as well as the average generation time (AGT) was calculated for untreated controls and for each of the IFN concentrations used, both in the blood cultures and in the KB cells. In the PBL cultures a clear dose-related inhibitory effect of IFN on cell division was observed, the RI values being lessened whereas the AGT concomitantly increased by increasing the IFN concentrations. An increase in M1 metaphase frequency was observed concomitantly with a diminished number of M3 cells. In KB cells the division kinetics was not influenced by IFN as indicated by similar RI and AGT values observed in controls and in IFN treated cells. However, the frequencies of both M1 and M3 cells were slightly diminished concomitantly with a discrete augmentation of M2 cell number. The differential staining of sister <span class="hlt">chromatid</span> thus proved a highly useful technique to investigate the different sensitivity of the normal and malignant cells to the growth inhibitory effect <span class="hlt">induced</span> by alpha IFN in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...120v3904G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...120v3904G"><span id="translatedtitle">Defect-<span class="hlt">induced</span> magnon scattering mechanisms in <span class="hlt">exchange</span>-coupled bilayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gallardo, R. A.; Rodríguez-Suárez, R. L.; Landeros, P.</p> <p>2016-12-01</p> <p>The influence of two-magnon scattering mechanisms, which may be activated by different sorts of defects, is theoretically studied in ferromagnetic/antiferromagnetic <span class="hlt">exchange</span>-biased bilayers. The spin-wave based model considers the influence of geometrical defects in the ferromagnetic (FM) layer as well as small domains in the antiferromagnetic (AFM) sub-lattice of the FM/AFM interface in such a way that both kinds of defects are randomly distributed over their respective surfaces. The in-plane angular dependence of the ferromagnetic resonance (FMR) linewidth allows detection of the relevant influence of such defects in the relaxation mechanisms, where the role of the <span class="hlt">exchange</span>-bias field is clearly identified. Typical experimental findings, such as quadratic dependence of the linewidth with the <span class="hlt">exchange</span>-bias field and the in-plane angular dependence, are well explained within the proposed model. This lends confidence in the model's utility and leads to a better understanding of the role of the magnon-magnon scattering in the magnetization dynamics of <span class="hlt">exchange</span>-coupled antiferromagnetic/ferromagnetic bilayers.</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('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('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('https://www.ncbi.nlm.nih.gov/pubmed/27116203','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27116203"><span id="translatedtitle">Characterization of Antimicrobial Agent Loaded Eudragit RS Solvent <span class="hlt">Exchange-Induced</span> In Situ Forming Gels for Periodontitis Treatment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Phaechamud, Thawatchai; Jantadee, Takron; Mahadlek, Jongjan; Charoensuksai, Purin; Pichayakorn, Wiwat</p> <p>2017-02-01</p> <p>Eudragit RS (ERS), a quaternary polyacrylate positively charged polymer, exhibits a very low permeability and swells in aqueous media independently of pH without dissolving. Owing to its high solubility in N-methyl pyrrolidone (NMP), it was interesting to apply as polymer matrix for solvent-<span class="hlt">exchanged</span> in situ forming gel. The aim of this research was to prepare in situ forming gels from ERS to deliver the antimicrobial agents (doxycycline hyclate, metronidazole, and benzoyl peroxide) for periodontitis treatment. They were evaluated for viscosity and rheology, gel formation, syringeability, drug release, and antimicrobial activities. The solvent <span class="hlt">exchange</span> between NMP and an external aqueous simulated gingival crevicular fluid stimulated the dissolved ERS transforming into the opaque rigid gel. Antimicrobial agent loaded ERS systems exhibited Newtonian flow with acceptable syringeability. The higher-loaded ERS promoted the more prolongation of drug release because of the retardation of water diffusion into the precipitated matrix. Antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans, and Porphyromonas gingivalis depended on type of drugs and test microorganisms. Doxycycline hyclate loaded ERS systems showed these activities greater than the others; however, all of them could inhibit all test microorganisms. Thus, the solvent <span class="hlt">exchange-induced</span> in situ forming gels comprising ERS-antimicrobial drugs exhibited potential use as localized delivery systems for periodontitis treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AdSpR..25.2107L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AdSpR..25.2107L"><span id="translatedtitle">Genomic Instability <span class="hlt">Induced</span> by High and Low Let Ionizing Radiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Limoli, C. L.; Ponnaiya, B.; Corcoran, J. J.; Giedzinski, E.; Kaplan, M. I.; Hartmann, A.; Morgan, W. F.</p> <p></p> <p>Genomic instability is the increased rate of acquisition of alterations in the mammalian genome, and includes such diverse biological endpoints as chromosomal destabilization, aneuploidy, micronucleus formation, sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span>, gene mutation and amplification, variations in colony size, reduced plating efficiency, and cellular transformation. Because these multiple endpoints persist long after initial radiation exposure, genomic instability has been proposed to operate as a driving force contributing to genetic plasticity and carcinogenic potential. Many of these radiation-<span class="hlt">induced</span> endpoints depend qualitatively and quantitatively on genetic background, dose and LET. Differences in the frequency and temporal expression of chromosomal instability depend on all three of the foregoing factors. On the other hand, many of these endpoints appear independent of dose and show bystander effects, implicating non-nuclear targets and epigenetic regulatory mechanisms. The present work will survey results concerning the LET dependence of genomic instability and the role of epigenetic mechanisms, with a particular emphasis on the endpoint of chromosomal in tability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dchromosome','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dchromosome"><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('https://www.ncbi.nlm.nih.gov/pubmed/17210183','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17210183"><span id="translatedtitle"><span class="hlt">Induced</span> binding of proteins by ammonium sulfate in affinity and ion-<span class="hlt">exchange</span> column chromatography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arakawa, Tsutomu; Tsumoto, Kouhei; Ejima, Daisuke; Kita, Yoshiko; Yonezawa, Yasushi; Tokunaga, Masao</p> <p>2007-04-10</p> <p>In general, proteins bind to affinity or ion-<span class="hlt">exchange</span> columns at low salt concentrations, and the bound proteins are eluted by raising the salt concentration, changing the solvent pH, or adding competing ligands. Blue-Sepharose is often used to remove bovine serum albumin (BSA) from samples, but when we applied BSA to Blue-Sepharose in 20 mM phosphate, pH 7.0, 50%-60% of the protein flowed through the column; however, complete binding of BSA was achieved by the addition of 2 M ammonium sulfate (AS) to the column equilibration buffer and the sample. The bound protein was eluted by decreasing the AS concentration or by adding 1 M NaCl or arginine. AS at high concentrations resulted in binding of BSA even to an ion-<span class="hlt">exchange</span> column, Q-Sepharose, at pH 7.0. Thus, although moderate salt concentrations elute proteins from Blue-Sepharose or ion-<span class="hlt">exchange</span> columns, proteins can be bound to these columns under extreme salting-out conditions. Similar enhanced binding of proteins by AS was observed with an ATP-affinity column.</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('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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3872193','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3872193"><span id="translatedtitle">Chromosome Segregation in Budding Yeast: Sister <span class="hlt">Chromatid</span> Cohesion and Related Mechanisms</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>2014-01-01</p> <p>Studies on budding yeast have exposed the highly conserved mechanisms by which duplicated chromosomes are evenly distributed to daughter cells at the metaphase–anaphase transition. The establishment of proteinaceous bridges between sister <span class="hlt">chromatids</span>, a function provided by a ring-shaped complex known as cohesin, is central to accurate segregation. It is the destruction of this cohesin that triggers the segregation of chromosomes following their proper attachment to microtubules. Since it is irreversible, this process must be tightly controlled and driven to completion. Furthermore, during meiosis, modifications must be put in place to allow the segregation of maternal and paternal chromosomes in the first division for gamete formation. Here, I review the pioneering work from budding yeast that has led to a molecular understanding of the establishment and destruction of cohesion. PMID:24395824</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24298060','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24298060"><span id="translatedtitle">The sister <span class="hlt">chromatid</span> cohesion pathway suppresses multiple chromosome gain and chromosome amplification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Covo, Shay; Puccia, Christopher M; Argueso, Juan Lucas; Gordenin, Dmitry A; Resnick, Michael A</p> <p>2014-02-01</p> <p>Gain or loss of chromosomes resulting in aneuploidy can be important factors in cancer and adaptive evolution. Although chromosome gain is a frequent event in eukaryotes, there is limited information on its genetic control. Here we measured the rates of chromosome gain in wild-type yeast and sister <span class="hlt">chromatid</span> cohesion (SCC) compromised strains. SCC tethers the newly replicated <span class="hlt">chromatids</span> until anaphase via the cohesin complex. Chromosome gain was measured by selecting and characterizing copper-resistant colonies that emerged due to increased copies of the metallothionein gene CUP1. Although all defective SCC diploid strains exhibited increased rates of chromosome gain, there were 15-fold differences between them. Of all mutants examined, a hypomorphic mutation at the cohesin complex caused the highest rate of chromosome gain while disruption of WPL1, an important regulator of SCC and chromosome condensation, resulted in the smallest increase in chromosome gain. In addition to defects in SCC, yeast cell type contributed significantly to chromosome gain, with the greatest rates observed for homozygous mating-type diploids, followed by heterozygous mating type, and smallest in haploids. In fact, wpl1-deficient haploids did not show any difference in chromosome gain rates compared to wild-type haploids. Genomic analysis of copper-resistant colonies revealed that the "driver" chromosome for which selection was applied could be amplified to over five copies per diploid cell. In addition, an increase in the expected driver chromosome was often accompanied by a gain of a small number of other chromosomes. We suggest that while chromosome gain due to SCC malfunction can have negative effects through gene imbalance, it could also facilitate opportunities for adaptive changes. In multicellular organisms, both factors could lead to somatic diseases including cancer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19262753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19262753"><span id="translatedtitle">The Elg1-RFC clamp-loading complex performs a role in 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>Maradeo, Marie E; Skibbens, Robert V</p> <p>2009-01-01</p> <p>It is widely accepted that of the four Replication Factor C (RFC) complexes (defined by the associations of either Rfc1p, Ctf18p, Elg1p or Rad24p with Rfc2p-Rfc5p), only Ctf18-RFC functions in sister <span class="hlt">chromatid</span> cohesion. This model is based on findings that CTF18 deletion is lethal in combination with mutations in either CTF7(ECO1) or MCD1 sister <span class="hlt">chromatid</span> cohesion genes and that ctf18 mutant cells exhibit cohesion defects. Here, we report that Elg1-RFC not only participates in cohesion but performs a function that is distinct from that of Ctf18-RFC. The results show that deletion of ELG1 rescues both ctf7(eco1) mutant cell temperature sensitivity and cohesion defects. Moreover, over-expression of ELG1 enhances ctf7(eco1) mutant cell phenotypes. These findings suggest that the balance of Ctf7p(Eco1p) activity depends on both Ctf18-RFC and Elg1-RFC. We also report that ELG1 deletion produces cohesion defects and intensifies the conditional phenotype of mcd1 mutant cells, further supporting a role for Elg1-RFC in cohesion. Attesting to the specificity of these interactions, deletion of RAD24 neither suppressed nor exacerbated cohesion defects in either ctf7(eco1) or mcd1 mutant cells. While parallel analyses failed to uncover a similar role in cohesion for Rad24-RFC, it is well known that Rad24-RFC, Elg1-RFC and Ctf18-RFC play key roles in DNA damage responses. We tested and found that Ctf7p(Eco1p) plays a significant role in Rad24-RFC-based DNA response pathways. In combination, these findings challenge current views and document new and distinct roles for RFC complexes in cohesion and for Ctf7p(Eco1p) in DNA repair.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26479775','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26479775"><span id="translatedtitle">Light-<span class="hlt">induced</span> cation <span class="hlt">exchange</span> for copper sulfide based CO2 reduction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Manzi, Aurora; Simon, Thomas; Sonnleitner, Clemens; Döblinger, Markus; Wyrwich, Regina; Stern, Omar; Stolarczyk, Jacek K; Feldmann, Jochen</p> <p>2015-11-11</p> <p>Copper(I)-based catalysts, such as Cu2S, are considered to be very promising materials for photocatalytic CO2 reduction. A common synthesis route for Cu2S via cation <span class="hlt">exchange</span> from CdS nanocrystals requires Cu(I) precursors, organic solvents, and neutral atmosphere, but these conditions are not compatible with in situ applications in photocatalysis. Here we propose a novel cation <span class="hlt">exchange</span> reaction that takes advantage of the reducing potential of photoexcited electrons in the conduction band of CdS and proceeds with Cu(II) precursors in an aqueous environment and under aerobic conditions. We show that the synthesized Cu2S photocatalyst can be efficiently used for the reduction of CO2 to carbon monoxide and methane, achieving formation rates of 3.02 and 0.13 μmol h(-1) g(-1), respectively, and suppressing competing water reduction. The process opens new pathways for the preparation of new efficient photocatalysts from readily available nanostructured templates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23985971','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23985971"><span id="translatedtitle">Strain engineering <span class="hlt">induced</span> interfacial self-assembly and intrinsic <span class="hlt">exchange</span> bias in a manganite perovskite film.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cui, B; Song, C; Wang, G Y; Mao, H J; Zeng, F; Pan, F</p> <p>2013-01-01</p> <p>The control of complex oxide heterostructures at atomic level generates a rich spectrum of exotic properties and unexpected states at the interface between two separately prepared materials. The frustration of magnetization and conductivity of manganite perovskite at surface/interface which is inimical to their device applications, could also flourish in tailored functionalities in return. Here we prove that the <span class="hlt">exchange</span> bias (EB) effect can unexpectedly emerge in a (La,Sr)MnO3 (LSMO) "single" film when large compressive stress imposed through a lattice mismatched substrate. The intrinsic EB behavior is directly demonstrated to be originating from the <span class="hlt">exchange</span> coupling between ferromagnetic LSMO and an unprecedented LaSrMnO4-based spin glass, formed under a large interfacial strain and subsequent self-assembly. The present results not only provide a strategy for producing a new class of delicately functional interface by strain engineering, but also shed promising light on fabricating the EB part of spintronic devices in a single step.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24844246','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24844246"><span id="translatedtitle">Pharmacological inhibition of cystine-glutamate <span class="hlt">exchange</span> <span class="hlt">induces</span> endoplasmic reticulum stress and ferroptosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dixon, Scott J; Patel, Darpan N; Welsch, Matthew; Skouta, Rachid; Lee, Eric D; Hayano, Miki; Thomas, Ajit G; Gleason, Caroline E; Tatonetti, Nicholas P; Slusher, Barbara S; Stockwell, Brent R</p> <p>2014-05-20</p> <p><span class="hlt">Exchange</span> of extracellular cystine for intracellular glutamate by the antiporter system xc (-) is implicated in numerous pathologies. Pharmacological agents that inhibit system xc (-) activity with high potency have long been sought, but have remained elusive. In this study, we report that the small molecule erastin is a potent, selective inhibitor of system xc (-). RNA sequencing revealed that inhibition of cystine-glutamate <span class="hlt">exchange</span> leads to activation of an ER stress response and upregulation of CHAC1, providing a pharmacodynamic marker for system xc (-) inhibition. We also found that the clinically approved anti-cancer drug sorafenib, but not other kinase inhibitors, inhibits system xc (-) function and can trigger ER stress and ferroptosis. In an analysis of hospital records and adverse event reports, we found that patients treated with sorafenib exhibited unique metabolic and phenotypic alterations compared to patients treated with other kinase-inhibiting drugs. Finally, using a genetic approach, we identified new genes dramatically upregulated in cells resistant to ferroptosis.DOI: http://dx.doi.org/10.7554/eLife.02523.001.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27859838','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27859838"><span id="translatedtitle">Aggregation-<span class="hlt">induced</span> changes in the chemical <span class="hlt">exchange</span> saturation transfer (CEST) signals of proteins.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goerke, Steffen; Milde, Katharina S; Bukowiecki, Raul; Kunz, Patrick; Klika, Karel D; Wiglenda, Thomas; Mogk, Axel; Wanker, Erich E; Bukau, Bernd; Ladd, Mark E; Bachert, Peter; Zaiss, Moritz</p> <p>2017-01-01</p> <p>Chemical <span class="hlt">exchange</span> saturation transfer (CEST) is an MRI technique that allows mapping of biomolecules (small metabolites, proteins) with nearly the sensitivity of conventional water proton MRI. In living organisms, several tissue-specific CEST effects have been observed and successfully applied to diagnostic imaging. In these studies, particularly the signals of proteins showed a distinct correlation with pathological changes. However, as CEST effects depend on various properties that determine and affect the chemical <span class="hlt">exchange</span> processes, the origins of the observed signal changes remain to be understood. In this study, protein aggregation was identified as an additional process that is encoded in the CEST signals of proteins. Investigation of distinct proteins that are involved in pathological disorders, namely amyloid beta and huntingtin, revealed a significant decrease of all protein CEST signals upon controlled aggregation. This finding is of particular interest with regard to diagnostic imaging of patients with neurodegenerative diseases that involve amyloidogenesis, such as Alzheimer's or Huntington's disease. To investigate whether the observed CEST signal decrease also occurs in heterogeneous mixtures of aggregated cellular proteins, and thus prospectively in tissue, heat-shocked yeast cell lysates were employed. Additionally, investigation of different cell compartments verified the assignment of the protein CEST signals to the soluble part of the proteome. The results of in vitro experiments demonstrate that aggregation affects the CEST signals of proteins. This observation can enable hypotheses for CEST imaging as a non-invasive diagnostic tool for monitoring pathological alterations of the proteome in vivo.</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('http://adsabs.harvard.edu/abs/2017ChOE...31...91K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ChOE...31...91K"><span id="translatedtitle">Experimental study on cross-flow <span class="hlt">induced</span> vibrations in heat <span class="hlt">exchanger</span> tube bundle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khushnood, Shahab; Nizam, Luqman Ahmad</p> <p>2017-03-01</p> <p>Vibration in heat <span class="hlt">exchangers</span> is one of the main problems that the industry has faced over last few decades. Vibration phenomenon in heat <span class="hlt">exchangers</span> is of major concern for designers and process engineers since it can lead to the tube damage, tube leakage, baffle damage, tube collision damage, fatigue, creep etc. In the present study, vibration response is analyzed on single tube located in the centre of the tube bundle having parallel triangular arrangement (60°) with P/ D ratio of 1.44. The experiment is performed for two different flow conditions. This kind of experiment has not been reported in the literature. Under the first condition, the tube vibration response is analyzed when there is no internal flow in the tube and under the second condition, the response is analyzed when the internal tube flow is maintained at a constant value of 0.1 m/s. The free stream shell side velocity ranges from 0.8 m/s to 1.3 m/s, the reduced gap velocity varies from 1.80 to 2.66 and the Reynolds number varies from 44500 to 66000. It is observed that the internal tube flow results in larger vibration amplitudes for the tube than that without internal tube flow. It is also established that over the current range of shell side flow velocity, the turbulence is the dominant excitation mechanism for producing vibration in the tube since the amplitude varies directly with the increase in the shell side velocity. Damping has no significant effect on the vibration behavior of the tube for the current velocity range.</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://adsabs.harvard.edu/abs/2017PhRvB..95k5306T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95k5306T"><span id="translatedtitle">Reduced <span class="hlt">exchange</span> narrowing caused by gate-<span class="hlt">induced</span> charge carriers in high-mobility donor-acceptor copolymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsutsumi, Jun'ya; Matsuoka, Satoshi; Osaka, Itaru; Kumai, Reiji; Hasegawa, Tatsuo</p> <p>2017-03-01</p> <p>Variations in exciton absorption resulting from charge accumulation in various semiconducting donor-acceptor (DA) copolymer thin films were systematically investigated by gate modulation (GM) spectroscopy by using the field-effect transistor device structure. The GM spectra obtained for high-mobility DA copolymer thin films exhibited second-derivative like line shapes due to an effect of spectral broadening of ordinary exciton absorption spectra by accumulated charges. In contrast, the GM spectra obtained for relatively low-mobility DA copolymer thin films exhibited simple bleaching of exciton absorption spectra, as well as observed for non-DA-type polymers like poly(3-hexylthiophene-2,5-diyl) (P3HT). From a systematic comparison of the GM spectra with temperature-dependent absorption spectra for the polymers in solution, we found that the spectral broadening observed in the GM spectra can be attributed to a reduced effect on the <span class="hlt">exchange</span> narrowing where excitonic transitions of individual polymer chains are coherently coupled within highly ordered crystalline domains in the polymer thin films. We discuss that the gate-<span class="hlt">induced</span> charge accumulation in the polymer films effects to suppress the exciton coherence length, which contributes to the reduced <span class="hlt">exchange</span> narrowing. We also discuss that the whole feature of the GM spectra can be understood in terms of a decomposition into ordered and disordered polymers and that the GM spectra can be used as fine probes for a degree of structural ordering in semiconductor channels of polymer field-effect transistors.</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('http://adsabs.harvard.edu/abs/1997NIMPB.131..321D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997NIMPB.131..321D"><span id="translatedtitle">Gamma irradiation-<span class="hlt">induced</span> modifications of polymers found in nuclear waste embedding processes Part II: The ion-<span class="hlt">exchange</span> resin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Debré, O.; Nsouli, B.; Thomas, J.-P.; Stevenson, I.; Colombini, D.; Romero, M.-A.</p> <p>1997-08-01</p> <p>Ion <span class="hlt">exchange</span> resins (IERs) saturated in cesium and borate ions are well representative of low and medium activity nuclear waste to be embedded in an epoxy resin/amine hardener, such a conditioning procedure being under qualification. In order to test these materials in realistic conditions they are externally irradiated (air and water), in mixed beds saturated in fixed ions (cesium and borate) and water. Irradiation effects are evidenced with the HSF-SIMS technique by the variation of the emission characteristic of both the fixed ions, the chemical structure of the IERs and their interrelationship, both from the analysis of the solid material and of the residual or rinsing water. It appears that the fixed ions can be released in surrounding water as a consequence of radiation-<span class="hlt">induced</span> resin fragments solubility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23419837','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23419837"><span id="translatedtitle">Refractory heparin <span class="hlt">induced</span> thrombocytopenia with thrombosis (HITT) treated with therapeutic plasma <span class="hlt">exchange</span> and rituximab as adjuvant therapy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schell, Amy M; Petras, Melissa; Szczepiorkowski, Zbigniew M; Ornstein, Deborah L</p> <p>2013-10-01</p> <p>We report a case of refractory heparin-<span class="hlt">induced</span> thrombocytopenia with thrombosis (HITT) with prolonged thrombocytopenia and multiple thrombotic complications that failed to improve despite aggressive treatment. A 60 year old female with a prior history of venous thromboembolism was admitted with an acute pulmonary embolism, and developed HITT after several days on heparin therapy. She suffered multiple complications including bilateral venous limb gangrene, acute renal failure, and refractory thrombocytopenia, leading us to use multimodality therapy including therapeutic plasma <span class="hlt">exchange</span> (TPE) and rituximab immunosuppression. The patient had transient improvements in her thrombocytopenia with TPE, and rituximab was added in an attempt to reduce antibody production. She eventually required bilateral limb amputation, and only after removal of the gangrenous limbs did her platelet count show sustained improvement. We discuss the possible contribution of infection to her prolonged course.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22486158','SCIGOV-STC'); return false;" href="https://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://adsabs.harvard.edu/abs/2015ApPhL.107v2404M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.107v2404M"><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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Q. L.; Iihama, S.; Zhang, X. M.; Miyazaki, T.; Mizukami, S.</p> <p>2015-11-01</p> <p>The laser-<span class="hlt">induced</span> spin dynamics of FeCo in perpendicularly magnetized L10-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('https://www.osti.gov/scitech/biblio/6696891','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6696891"><span id="translatedtitle">The effect of flat bar supports on the crossflow <span class="hlt">induced</span> response of heat <span class="hlt">exchanger</span> U-tubes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weaver, D.S.; Schneider, W.</p> <p>1982-10-01</p> <p>A wind tunnel study was conducted to determine the effect of flat bar supports on the crossflow <span class="hlt">induced</span> response of heat <span class="hlt">exchanger</span> U-tubes. The 13-mm-dia tubes formed a triangular array with a pitch ratio of 1.57 and a mean U-bend diameter of about 1.5 m. A 0.3-m-long section of the array was exposed to a flow parallel to the plane of the U-bends. Experiments were conducted with no supports, with one set of flat bars at the apex, and with two sets of flat bar supports at the apex and 45 deg points. In each case, the tube response was monitored to a flow velocity beyond that required for fluid elastic instability. Limited experiments were also conducted to examine the effect of tube support clearance on tube response. Conclusions are drawn regarding the effectiveness of flat bars as U-bend antivibration supports.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5551998','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5551998"><span id="translatedtitle">The effect of flat bar supports on the cross flow <span class="hlt">induced</span> response of heat <span class="hlt">exchanger</span> U-tubes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weaver, D.S.; Schneider, W.</p> <p>1982-01-01</p> <p>A wind tunnel study was conducted to determine the effect of flat bar supports on the cross-flow <span class="hlt">induced</span> response of heat <span class="hlt">exchanger</span> U-tubes. The 13 mm diameter tubes formed a triangular array with a pitch ratio o 1.57 and a mean U-bend diameter of about 1.5 m. A 0.3 m long section of the array was exposed to a flow parallel to the plane of the U-bends. Experiments were conducted with no supports, with 1 set of flat bars at the apex and with 2 sets of flat bar supports at the apex and 45/sup 0/ points. In each case, the tube response was monitored to a flow velocity beyond that required for fluid elastic instability. Limited experiments were also conducted to examine the effect of tube support clearance on tube response. Conclusions are drawn regarding the effectiveness of flat bars as U-bend antivibration supports.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21335991','SCIGOV-STC'); return false;" href="https://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.osti.gov/scitech/biblio/974629','SCIGOV-STC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/11389843','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11389843"><span id="translatedtitle">Identification of RFC(Ctf18p, Ctf8p, Dcc1p): an alternative RFC complex required for sister <span class="hlt">chromatid</span> cohesion in S. cerevisiae.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mayer, M L; Gygi, S P; Aebersold, R; Hieter, P</p> <p>2001-05-01</p> <p>We have identified and characterized an alternative RFC complex RFC(Ctf18p, Ctf8p, Dcc1p) that is required for sister <span class="hlt">chromatid</span> cohesion and faithful chromosome transmission. Ctf18p, Ctf8p, and Dcc1p interact physically in a complex with Rfc2p, Rfc3p, Rfc4p, and Rfc5p but not with Rfc1p or Rad24p. Deletion of CTF18, CTF8, or DCC1 singly or in combination (ctf18Deltactf8Deltadcc1Delta) leads to sensitivity to microtubule depolymerizing drugs and a severe sister <span class="hlt">chromatid</span> cohesion defect. Furthermore, temperature-sensitive mutations in RFC4 result in precocious sister <span class="hlt">chromatid</span> separation. Our results highlight a novel function of the RFC proteins and support a model in which sister <span class="hlt">chromatid</span> cohesion is established at the replication fork via a polymerase switching mechanism and a replication-coupled remodeling of chromatin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24844569','PUBMED'); return false;" href="https://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.</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://www.dtic.mil/docs/citations/ADA184570','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA184570"><span id="translatedtitle">Field Verification Program (Aquatic Disposal). Sister <span class="hlt">Chromatid</span> <span class="hlt">Exchange</span> in Marine Polychaetes Exposed to Black Rock Harbor Sediment.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1985-07-01</p> <p>Environmental Laboratory. Manager of the Environ- mental Effects of Dredging Programs was Dr. Robert M. Engler, with Mr. Robert L. Lazor , FVP Coordinator...34,000 4,900 - .4. PAH po i,, nuclear ar omatl ; 0,4. .. . .. I, , ’ " , ml m m m m - ml . m m m mm. m m m - .,, ,, -D-RiS4 578 FIELD VERIFICATION PROGRAM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19893489','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19893489"><span id="translatedtitle">Tipin/Tim1/And1 protein complex promotes Pol alpha chromatin binding 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>Errico, Alessia; Cosentino, Claudia; Rivera, Teresa; Losada, Ana; Schwob, Etienne; Hunt, Tim; Costanzo, Vincenzo</p> <p>2009-12-02</p> <p>The Tipin/Tim1 complex plays an important role in the S-phase checkpoint and replication fork stability. However, the biochemical function of this complex is poorly understood. Using Xenopus laevis egg extract we show that Tipin is required for DNA replication in the presence of limiting amount of replication origins. Under these conditions the DNA replication defect correlates with decreased levels of DNA Polalpha on chromatin. We identified And1, a Polalpha chromatin-loading factor, as new Tipin-binding partner. We found that both Tipin and And1 promote stable binding of Polalpha to chromatin and that this is required for DNA replication under unchallenged conditions. Strikingly, extracts lacking Tipin and And1 also show reduced sister <span class="hlt">chromatids</span> cohesion. These data indicate that Tipin/Tim1/And1 form a complex that links stabilization of replication fork and establishment of sister <span class="hlt">chromatid</span> cohesion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5171793','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5171793"><span id="translatedtitle">Naa50/San-dependent N-terminal acetylation of Scc1 is potentially important for 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>Ribeiro, Ana Luisa; Silva, Rui D.; Foyn, Håvard; Tiago, Margarida N.; Rathore, Om Singh; Arnesen, Thomas; Martinho, Rui Gonçalo</p> <p>2016-01-01</p> <p>The gene separation anxiety (san) encodes Naa50/San, a N-terminal acetyltransferase required for chromosome segregation during mitosis. Although highly conserved among higher eukaryotes, the mitotic function of this enzyme is still poorly understood. Naa50/San was originally proposed to be required for centromeric sister <span class="hlt">chromatid</span> cohesion in Drosophila and human cells, yet, more recently, it was also suggested to be a negative regulator of microtubule polymerization through internal acetylation of beta Tubulin. We used genetic and biochemical approaches to clarify the function of Naa50/San during development. Our work suggests that Naa50/San is required during tissue proliferation for the correct interaction between the cohesin subunits Scc1 and Smc3. Our results also suggest a working model where Naa50/San N-terminally acetylates the nascent Scc1 polypeptide, and that this co-translational modification is subsequently required for the establishment and/or maintenance of sister <span class="hlt">chromatid</span> cohesion. PMID:27996020</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/75589','SCIGOV-STC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/23620524','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23620524"><span id="translatedtitle">Immune tolerance <span class="hlt">induced</span> using plasma <span class="hlt">exchange</span> and rituximab in an infantile Pompe disease patient.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deodato, Federica; Ginocchio, Virginia Maria; Onofri, Alfredo; Grutter, Giorgia; Germani, Alessandro; Dionisi-Vici, Carlo</p> <p>2014-06-01</p> <p>Infantile Pompe disease, resulting from deficiency of lysosomal acid α-glucosidase, requires enzyme replacement therapy with recombinant human acid α-glucosidase. Most patients develop antirecombinant human acid α-glucosidase antibodies, leading to reduced response to enzyme therapy in a subgroup of them. Aiming to improve treatment response, several immune tolerance induction strategies have been explored. We describe a patient with life-threatening infusion-associated reactions presenting anti-recombinant human acid α-glucosidase antibodies. He was successfully treated with an immune tolerance induction protocol, consisting of plasma <span class="hlt">exchange</span> combined with a single dose of rituximab. Immediate reduction of antibody titer was obtained and enzyme therapy was resumed without infusion-associated reactions. Twenty-two months later, immunoglobulin G titer remained below 1:100. In conclusion, we applied a short-course immune tolerance induction strategy in a patient with severe infusion-associated reactions and anti-recombinant human acid α-glucosidase antibodies, leading to early and persisting reduction of antibody titer, in the absence of significant adverse events.</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.ncbi.nlm.nih.gov/pubmed/23681662','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23681662"><span id="translatedtitle">A CO-FISH assay to assess sister <span class="hlt">chromatid</span> segregation patterns in mitosis of mouse embryonic stem cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sauer, Stephan; Burkett, Sandra S; Lewandoski, Mark; Klar, Amar J S</p> <p>2013-05-01</p> <p>Sister <span class="hlt">chromatids</span> contain identical DNA sequence but are chiral with respect to both their helical handedness and their replication history. Emerging evidence from various model organisms suggests that certain stem cells segregate sister <span class="hlt">chromatids</span> nonrandomly to either maintain genome integrity or to bias cellular differentiation in asymmetric cell divisions. Conventional methods for tracing of old vs. newly synthesized DNA strands generally lack resolution for individual chromosomes and employ halogenated thymidine analogs with profound cytotoxic effects on rapidly dividing cells. Here, we present a modified chromosome orientation fluorescence in situ hybridization (CO-FISH) assay, where identification of individual chromosomes and their replication history is achieved in subsequent hybridization steps with chromosome-specific DNA probes and PNA telomere probes. Importantly, we tackle the issue of BrdU cytotoxicity and show that our method is compatible with normal mouse ES cell biology, unlike a recently published related protocol. Results from our CO-FISH assay show that mitotic segregation of mouse chromosome 7 is random in ES cells, which contrasts previously published results from our laboratory and settles a controversy. Our straightforward protocol represents a useful resource for future studies on <span class="hlt">chromatid</span> segregation patterns of in vitro-cultured cells from distinct model organisms.</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('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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5249256','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5249256"><span id="translatedtitle">ASXL1 interacts with the cohesin complex to maintain <span class="hlt">chromatid</span> separation and gene expression for normal hematopoiesis</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, Zhaomin; Zhang, Peng; Yan, Aimin; Guo, Zhengyu; Ban, Yuguang; Li, Jin; Chen, Shi; Yang, Hui; He, Yongzheng; Li, Jianping; Guo, Ying; Zhang, Wen; Hajiramezanali, Ehsan; An, Huangda; Fajardo, Darlene; Harbour, J. William; Ruan, Yijun; Nimer, Stephen D.; Yu, Peng; Chen, Xi; Xu, Mingjiang; Yang, Feng-Chun</p> <p>2017-01-01</p> <p>ASXL1 is frequently mutated in a spectrum of myeloid malignancies with poor prognosis. Loss of Asxl1 leads to myelodysplastic syndrome–like disease in mice; however, the underlying molecular mechanisms remain unclear. We report that ASXL1 interacts with the cohesin complex, which has been shown to guide sister <span class="hlt">chromatid</span> segregation and regulate gene expression. Loss of Asxl1 impairs the cohesin function, as reflected by an impaired telophase <span class="hlt">chromatid</span> disjunction in hematopoietic cells. Chromatin immunoprecipitation followed by DNA sequencing data revealed that ASXL1, RAD21, and SMC1A share 93% of genomic binding sites at promoter regions in Lin−cKit+ (LK) cells. We have shown that loss of Asxl1 reduces the genome binding of RAD21 and SMC1A and alters the expression of ASXL1/cohesin target genes in LK cells. Our study underscores the ASXL1-cohesin interaction as a novel means to maintain normal sister <span class="hlt">chromatid</span> separation and regulate gene expression in hematopoietic cells. PMID:28116354</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://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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686863','PMC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/26423134','PUBMED'); return false;" href="https://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>2015-10-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20980821','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20980821"><span id="translatedtitle">Rfc5p regulates alternate RFC complex functions in sister <span class="hlt">chromatid</span> pairing reactions in budding yeast.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maradeo, Marie E; Garg, Anisha; Skibbens, Robert V</p> <p>2010-11-01</p> <p>Sister <span class="hlt">chromatid</span> pairing reactions, termed cohesion establishment, occur during S-phase and appear to be regulated by Replication Factor C (RFC) complexes. For instance, RFCs that contain Ctf18p exhibit pro-establishment activities while those that contain Elg1p exhibit anti-establishment activities. It remains unknown whether Ctf18p-RFC and Elg1p-RFC functions are simply opposing or instead reveal complicated and non-parallel regulatory mechanisms. To better understand the nature of these novel pathways, we analyzed the small RFC subunit Rfc5p that is common to both Ctf18p-RFC and Elg1p-RFC. Despite this commonality, the data show that diminished Rfc5p function rescues ctf7/eco1 mutant cell phenotypes, revealing that Rfc5p promotes anti-establishment activities. This rescue is specific to establishment pathways in that rfc5-1 greatly accentuates growth defects when expressed in scc2 (deposition), mcd1/scc1 or smc3 (cohesion maintenance) mutated cells. Our results reveal for the first time a role for small RFC subunits in directing RFC complex functions-in this case towards anti-establishment pathways. We further report that Pds5p exhibits both establishment and anti-establishment functions in cohesion. This duality suggests that categorizations of establishment and anti-establishment activities require further examination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4586513','PMC'); return false;" href="https://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/25877869','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25877869"><span id="translatedtitle">The nucleotide <span class="hlt">exchange</span> factors Grp170 and Sil1 <span class="hlt">induce</span> cholera toxin release from BiP to enable retrotranslocation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Williams, Jeffrey M; Inoue, Takamasa; Chen, Grace; Tsai, Billy</p> <p>2015-06-15</p> <p>Cholera toxin (CT) intoxicates cells by trafficking from the cell surface to the endoplasmic reticulum (ER), where the catalytic CTA1 subunit hijacks components of the ER-associated degradation (ERAD) machinery to retrotranslocate to the cytosol and <span class="hlt">induce</span> toxicity. In the ER, CT targets to the ERAD machinery composed of the E3 ubiquitin ligase Hrd1-Sel1L complex, in part via the activity of the Sel1L-binding partner ERdj5. This J protein stimulates BiP's ATPase activity, allowing BiP to capture the toxin. Presumably, toxin release from BiP must occur before retrotranslocation. Here, using loss-and gain-of-function approaches coupled with binding studies, we demonstrate that the ER-resident nucleotide <span class="hlt">exchange</span> factors (NEFs) Grp170 and Sil1 <span class="hlt">induce</span> CT release from BiP in order to promote toxin retrotranslocation. In addition, we find that after NEF-dependent release from BiP, the toxin is transferred to protein disulfide isomerase; this ER redox chaperone is known to unfold CTA1, which allows the toxin to cross the Hrd1-Sel1L complex. Our data thus identify two NEFs that trigger toxin release from BiP to enable successful retrotranslocation and clarify the fate of the toxin after it disengages from BiP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25830299','PUBMED'); return false;" href="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4462937','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4462937"><span id="translatedtitle">The nucleotide <span class="hlt">exchange</span> factors Grp170 and Sil1 <span class="hlt">induce</span> cholera toxin release from BiP to enable retrotranslocation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Williams, Jeffrey M.; Inoue, Takamasa; Chen, Grace; Tsai, Billy</p> <p>2015-01-01</p> <p>Cholera toxin (CT) intoxicates cells by trafficking from the cell surface to the endoplasmic reticulum (ER), where the catalytic CTA1 subunit hijacks components of the ER-associated degradation (ERAD) machinery to retrotranslocate to the cytosol and <span class="hlt">induce</span> toxicity. In the ER, CT targets to the ERAD machinery composed of the E3 ubiquitin ligase Hrd1-Sel1L complex, in part via the activity of the Sel1L-binding partner ERdj5. This J protein stimulates BiP's ATPase activity, allowing BiP to capture the toxin. Presumably, toxin release from BiP must occur before retrotranslocation. Here, using loss-and gain-of-function approaches coupled with binding studies, we demonstrate that the ER-resident nucleotide <span class="hlt">exchange</span> factors (NEFs) Grp170 and Sil1 <span class="hlt">induce</span> CT release from BiP in order to promote toxin retrotranslocation. In addition, we find that after NEF-dependent release from BiP, the toxin is transferred to protein disulfide isomerase; this ER redox chaperone is known to unfold CTA1, which allows the toxin to cross the Hrd1-Sel1L complex. Our data thus identify two NEFs that trigger toxin release from BiP to enable successful retrotranslocation and clarify the fate of the toxin after it disengages from BiP. PMID:25877869</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011RaPC...80..803C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011RaPC...80..803C"><span id="translatedtitle">Comparative studies on performance of radiation-<span class="hlt">induced</span> and thermal cross-linked ion-<span class="hlt">exchange</span> membrane for water electrolysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chakrabarty, Tina; Jasti, Amaranadh; Goel, N. K.; Shahi, Vinod K.; Sabharwal, Sunil</p> <p>2011-07-01</p> <p>Radiation-<span class="hlt">induced</span> and thermal cross-linked sulfonated poly(ether sulfone) (SPS)-sulfonated poly(ether ether ketone) (SPK) composite ion-<span class="hlt">exchange</span> membranes (SPS/SPK(γ) and SPS/SPK(T), respectively) were prepared. Their performances for water electrolysis were comparatively assessed. Thermal cross-linked membrane (SPS/SPK(T)) showed cross-linking of part functional groups (-SO 3H) and thus deterioration in membrane conductivity. While, radiation-<span class="hlt">induced</span> cross-linked membrane (SPS/SPK(γ)) avoided any cross-linking between functional groups and thus conductivity. Electrolysis performances of these membranes were evaluated in comparison with Nafion117 membrane. Relatively low current efficiency (CE) for SPS/SPK and SPS/SPK(T) membranes was due to their high mass transfer (water) via electro-osmotic drag, which was negligible for SPS/SPK(γ) membrane. SPS/SPK(γ) membrane exhibited comparable stabilities and water splitting performance with Nafion117 membrane, which revealed its suitability as substitute for electrochemical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7033558','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7033558"><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="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kelsey, K.T.; Xia, F.; Christiani, D.C.; Liber, H.L.; Spengler, J.D.; Dockery, D.W. ); Bodell, W.J. )</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 materials. 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 [sup 32]P-postlabeling assay, no increase in DNA adduct formation was observed in AHH-1 cells treated with particulates isolated from sampling in Kuwait. 18 refs., 4 figs.</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('http://adsabs.harvard.edu/abs/2014WRR....50.6168A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.6168A"><span id="translatedtitle">Comparison of effects of inset floodplains and hyporheic <span class="hlt">exchange</span> <span class="hlt">induced</span> by in-stream structures on solute retention</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azinheira, David L.; Scott, Durelle T.; Hession, W.; Hester, Erich T.</p> <p>2014-07-01</p> <p>The pollution of streams and rivers is a growing concern, and environmental guidance increasingly suggests stream restoration to improve water quality. Solute retention in off-channel storage zones, such as hyporheic zones and floodplains, is typically necessary for significant reaction to occur. Yet, the effects of two common restoration techniques, in-stream structures and inset floodplains, on solute retention have not been rigorously compared. We used MIKE SHE to model hydraulics and solute transport in the channel, on inset floodplains, and in structure-<span class="hlt">induced</span> hyporheic zones of a third-order stream. We varied hydraulic conditions (winter base flow, summer base flow, and stormflow), geology (hydraulic conductivity), and stream restoration design parameters (inset floodplain length and presence of in-stream structures). The in-stream structures <span class="hlt">induced</span> hyporheic <span class="hlt">exchange</span> for approximately 20% of the year (during summer base flow) while inset floodplains were active for approximately 1% of the year (during stormflow). Flow onto inset floodplains and residence times in both the channel and on the floodplains increased nonlinearly with the fraction of bank with floodplains installed. The fraction of streamflow that flowed onto the inset floodplains was 1-3 orders of magnitude higher than that which flowed through the structure-<span class="hlt">induced</span> hyporheic zone. Yet, residence times and mass storage in the hyporheic zone were 1-5 orders of magnitude larger than that on individual inset floodplains. In our modeling, neither in-stream structures nor inset floodplains had sufficient percent flow and residence times simultaneously to have a substantial impact on dissolved contaminants flowing downstream.</p> </li> <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('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('https://www.ncbi.nlm.nih.gov/pubmed/25964420','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25964420"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Verberk, Wilco C E P; Bilton, David T</p> <p>2015-07-01</p> <p>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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22043856','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22043856"><span id="translatedtitle">Hydrogen <span class="hlt">exchange</span> mass spectrometry of bacteriorhodopsin reveals light-<span class="hlt">induced</span> changes in the structural dynamics of a biomolecular machine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pan, Yan; Brown, Leonid; Konermann, Lars</p> <p>2011-12-21</p> <p>Many proteins act as molecular machines that are fuelled by a nonthermal energy source. Examples include transmembrane pumps and stator-rotor complexes. These systems undergo cyclic motions (CMs) that are being driven along a well-defined conformational trajectory. Superimposed on these CMs are thermal fluctuations (TFs) that are coupled to stochastic motions of the solvent. Here we explore whether the TFs of a molecular machine are affected by the occurrence of CMs. Bacteriorhodopsin (BR) is a light-driven proton pump that serves as a model system in this study. The function of BR is based on a photocycle that involves trans/cis isomerization of a retinal chromophore, as well as motions of transmembrane helices. Hydrogen/deuterium <span class="hlt">exchange</span> (HDX) mass spectrometry was used to monitor the TFs of BR, focusing on the monomeric form of the protein. Comparative HDX studies were conducted under illumination and in the dark. The HDX kinetics of BR are dramatically accelerated in the presence of light. The isotope <span class="hlt">exchange</span> rates and the number of backbone amides involved in EX2 opening transitions increase roughly 2-fold upon illumination. In contrast, light/dark control experiments on retinal-free protein produced no discernible differences. It can be concluded that the extent of TFs in BR strongly depends on photon-driven CMs. The light-<span class="hlt">induced</span> differences in HDX behavior are ascribed to protein destabilization. Specifically, the thermodynamic stability of the dark-adapted protein is estimated to be 5.5 kJ mol(-1) under the conditions of our work. This value represents the free energy difference between the folded state F and a significantly unfolded conformer U. Illumination reduces the stability of F by 2.2 kJ mol(-1). Mechanical agitation caused by isomerization of the chromophore is transferred to the surrounding protein scaffold, and subsequently, the energy dissipates into the solvent. Light-<span class="hlt">induced</span> retinal motions therefore act analogously to an internal heat</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('https://www.ncbi.nlm.nih.gov/pubmed/25378582','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25378582"><span id="translatedtitle">A novel mechanism for the establishment of sister <span class="hlt">chromatid</span> cohesion by the ECO1 acetyltransferase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guacci, Vincent; Stricklin, Jeremiah; Bloom, Michelle S; Guō, Xuánzōng; Bhatter, Meghna; Koshland, Douglas</p> <p>2015-01-01</p> <p>Cohesin complex mediates cohesion between sister <span class="hlt">chromatids</span>, which promotes high-fidelity chromosome segregation. Eco1p acetylates the cohesin subunit Smc3p during S phase to establish cohesion. The current model posits that this Eco1p-mediated acetylation promotes establishment by abrogating the ability of Wpl1p to destabilize cohesin binding to chromosomes. Here we present data from budding yeast that is incompatible with this Wpl1p-centric model. Two independent in vivo assays show that a wpl1∆ fails to suppress cohesion defects of eco1∆ cells. Moreover, a wpl1∆ also fails to suppress cohesion defects engendered by blocking just the essential Eco1p acetylation sites on Smc3p (K112, K113). Thus removing WPL1 inhibition is insufficient for generating cohesion without ECO1 activity. To elucidate how ECO1 promotes cohesion, we conducted a genetic screen and identified a cohesion activator mutation in the SMC3 head domain (D1189H). Smc3-D1189H partially restores cohesion in eco1∆ wpl1∆ or eco1 mutant cells but robustly restores cohesion in cells blocked for Smc3p K112 K113 acetylation. These data support two important conclusions. First, acetylation of the K112 K113 region by Eco1p promotes cohesion establishment by altering Smc3p head function independent of its ability to antagonize Wpl1p. Second, Eco1p targets other than Smc3p K112 K113 are necessary for efficient establishment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://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="https://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/2011JPS...196..614A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPS...196..614A"><span id="translatedtitle">Characterization of polyethyleneterephthalate (PET) based proton <span class="hlt">exchange</span> membranes prepared by UV-radiation-<span class="hlt">induced</span> graft copolymerization of styrene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahmed, Mostak; Khan, Mohammad B.; Khan, Mubarak A.; Alam, S. Shamsul; Halim, Md. Abdul; Khan, M. Anwar H.</p> <p></p> <p>Polymer electrolyte membranes (PEMs) were successfully prepared by simultaneous ultraviolet (UV) radiation-<span class="hlt">induced</span> graft copolymerization of styrene (35 vol.% concentration) onto poly(ethyleneterephthalate) (PET) film, followed by sulfonation on the styrene monomer units in the grafting chain using 0.05 M chlorosulfonic acid (ClSO 3H). The radiation grafting and the sulfonation have been confirmed by titrimetric and gravimetric analyses as well as Fourier Transform Infrared (FTIR) spectroscopy. The maximum ion-<span class="hlt">exchange</span> capacity (IEC) of the PEM was measured to be 0.04385 mmol g -1 at its highest level of grafting and sulfonation. They exhibited high thermal and mechanical properties as well as oxidative stability. They are highly stable in H 2SO 4 solutions and can be used in the acidic fuel cells. The membranes showed low water uptake as well as low proton conductivity than Nafion. In this study, the preparation of PEMs from commodity-type polymers is found to be very inexpensive and is a suitable candidate for applications in fuel cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26951505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26951505"><span id="translatedtitle">Designing Solvent <span class="hlt">Exchange-Induced</span> In Situ Forming Gel from Aqueous Insoluble Polymers as Matrix Base for Periodontitis Treatment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srichan, Tharatree; Phaechamud, Thawatchai</p> <p>2017-01-01</p> <p>An in situ forming gel is a dosage form which is promised for site-specific therapy such as periodontal pocket of periodontitis treatment. Ethylcellulose, bleached shellac, and Eudragit RS were applied in this study as a polymeric matrix for in situ forming gel employing N-methyl pyrrolidone (NMP) as solvent. Solutions comprising ethylcellulose, bleached shellac, and Eudragit RS in NMP were evaluated for viscosity, rheology, and rate of water penetration. Ease of administration by injection was determined as the force required to expel polymeric solutions through a needle using texture analyzer. In vitro gel formation and in vitro gel degradation were conducted after injection into phosphate buffer solution pH 6.8. Ethylcellulose, bleached shellac, and Eudragit RS could form the in situ gel, in vitro. Gel viscosity and pH value depended on percentage amount of the polymer, whereas the water diffusion at early period likely relied on types of polymer. Furthermore, the solutions containing higher polymer concentration exhibited the lower degree of degradation. All the preparations were acceptable as injectable dosage forms because the applied force was lower than 50 N. All of them inhibited Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans, and Porphyrommonas gingivalis growth owing to antimicrobial activity of NMP which exhibited a potential use for periodontitis treatment. Moreover, the developed systems presented as the solvent <span class="hlt">exchange</span> <span class="hlt">induced</span> in situ forming gel and showed capability to be incorporated with the suitable antimicrobial active compounds for periodontitis treatment which should be further studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28343969','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28343969"><span id="translatedtitle">Pds5 Regulates Sister-<span class="hlt">Chromatid</span> Cohesion and Chromosome Bi-orientation through a Conserved Protein Interaction Module.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goto, Yuhei; Yamagishi, Yuya; Shintomi-Kawamura, Miyuki; Abe, Mayumi; Tanno, Yuji; Watanabe, Yoshinori</p> <p>2017-04-03</p> <p>Sister-<span class="hlt">chromatid</span> cohesion is established by the cohesin complex in S phase and persists until metaphase, when sister <span class="hlt">chromatids</span> are captured by microtubules emanating from opposite poles [1]. The Aurora-B-containing chromosome passenger complex (CPC) plays a crucial role in achieving chromosome bi-orientation by correcting erroneous microtubule attachment [2]. The centromeric localization of the CPC relies largely on histone H3-T3 phosphorylation (H3-pT3), which is mediated by the mitotic histone kinase Haspin/Hrk1 [3-5]. Hrk1 localization to centromeres depends largely on the cohesin subunit Pds5 in fission yeast [5]; however, it is unknown how Pds5 regulates Hrk1 localization. Here we identify a conserved Hrk1-interacting motif (HIM) in Pds5 and a Pds5-interacting motif (PIM) in Hrk1 in fission yeast. Mutations in either motif result in the displacement of Hrk1 from centromeres. We also show that the mechanism of Pds5-dependent Hrk1 recruitment is conserved in human cells. Notably, the PIM in Haspin/Hrk1 is reminiscent of the YSR motif found in the mammalian cohesin destabilizer Wapl and stabilizer Sororin, both of which bind PDS5 [6-12]. Similarly, and through the same motifs, fission yeast Pds5 binds to Wpl1/Wapl and acetyltransferase Eso1/Eco1, in addition to Hrk1. Thus, we have identified a protein-protein interaction module in Pds5 that serves as a chromatin platform for regulating sister-<span class="hlt">chromatid</span> cohesion and chromosome bi-orientation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23444375','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23444375"><span id="translatedtitle">Overexpression of SETβ, a protein localizing to centromeres, causes precocious separation of <span class="hlt">chromatids</span> during the first meiosis of mouse oocytes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qi, Shu-Tao; Wang, Zhen-Bo; Ouyang, Ying-Chun; Zhang, Qing-Hua; Hu, Meng-Wen; Huang, Xin; Ge, Zhaojia; Guo, Lei; Wang, Ya-Peng; Hou, Yi; Schatten, Heide; Sun, Qing-Yuan</p> <p>2013-04-01</p> <p>Chromosome segregation in mammalian oocyte meiosis is an error-prone process, and any mistake in this process may result in aneuploidy, which is the main cause of infertility, abortion and many genetic diseases. It is now well known that shugoshin and protein phosphatase 2A (PP2A) play important roles in the protection of centromeric cohesion during the first meiosis. PP2A can antagonize the phosphorylation of rec8, a member of the cohesin complex, at the centromeres and thus prevent cleavage of rec8 and so maintain the cohesion of <span class="hlt">chromatids</span>. SETβ is a protein that physically interacts with shugoshin and inhibits PP2A activity. We thus hypothesized that SETβ might regulate cohesion protection and chromosome segregation during oocyte meiotic maturation. Here we report for the first time the expression, subcellular localization and functions of SETβ during mouse oocyte meiosis. Immunoblotting analysis showed that the expression level of SETβ was stable from the germinal vesicle stage to the MII stage of oocyte meiosis. Immunofluorescence analysis showed SETβ accumulation in the nucleus at the germinal vesicle stage, whereas it was targeted mainly to the inner centromere area and faintly localized to the interchromatid axes from germinal vesicle breakdown to MI stages. At the MII stage, SETβ still localized to the inner centromere area, but could relocalize to kinetochores in a process perhaps dependent on the tension on the centromeres. SETβ partly colocalized with PP2A at the inner centromere area. Overexpression of SETβ in mouse oocytes caused precocious separation of sister <span class="hlt">chromatids</span>, but depletion of SETβ by RNAi showed little effects on the meiotic maturation process. Taken together, our results suggest that SETβ, even though it localizes to centromeres, might not be essential for chromosome separation during mouse oocyte meiotic maturation, although its forced overexpression causes premature <span class="hlt">chromatid</span> separation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://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="https://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 PAGES</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; ...</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.ncbi.nlm.nih.gov/pubmed/26576658','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26576658"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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 |∆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.</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('https://www.osti.gov/scitech/biblio/276718','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/276718"><span id="translatedtitle">Generation of light-<span class="hlt">induced</span> electrical potential from ion <span class="hlt">exchange</span> membranes containing 4,4{prime}-bipyridine moiety</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sata, Toshikatsu</p> <p>1996-07-15</p> <p>Ion <span class="hlt">exchange</span> membranes, which are some of the most advanced separation membranes, are widely used in industry, i.e., in electrodialysis processes, diffusion dialysis processes, as separators for electrolysis, solid polyelectrolytes for fuel cells, etc. Generation of photovoltage and photocurrent from ion <span class="hlt">exchange</span> membranes containing a viologen moiety was examined, cation <span class="hlt">exchange</span> membranes ion-<span class="hlt">exchanged</span> with methyl viologen and anion <span class="hlt">exchange</span> membranes to which a viologen moiety was bonded. After the membrane, swelled with ethylene glycol, had been clamped between two ITO electrodes and sealed, it was irradiated with a xenon lamp. In the case of the cation <span class="hlt">exchange</span> membranes ion-<span class="hlt">exchanged</span> with methyl viologen, 155.3 mV of photo-voltage was observed immediately after photoirradiation, and the voltage decreased and attained almost a constant value. The photovoltage of anion <span class="hlt">exchange</span> membranes with the viologen moiety increased very slowly (maximum 81 mV, 405 nA; load resistance 200 K{Omega}) after beginning the irradiation. However, when the light was irradiated again on the membrane after interruption of the irradiation, almost the same photovoltage was generated immediately after the irradiation. Though the anion <span class="hlt">exchange</span> membrane showed absorbance only at 320 nm in the UV-VIS spectrum, wavelengths between 300 and 400 nm were active to reduce the viologen moiety of the membrane. This might be due to a polymer effect. On the other hand, the electrical resistance between the ITO electrodes decreased upon photoirradiation because of radical formation. In order to accelerate generation of the voltage, an oxidative agent (ferric ions) or a reductive agent (triethanolamine) was added to the system. The photovoltage was generated immediately after irradiation in both cases. Ferric ions act as an electron acceptor and triethanolamine forms cation radicals in the membrane before the irradiation.</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('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://adsabs.harvard.edu/abs/2016PhRvC..94e4610S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvC..94e4610S"><span id="translatedtitle">Emission of neutron-proton and proton-proton pairs in electron scattering <span class="hlt">induced</span> by meson-<span class="hlt">exchange</span> currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simo, I. Ruiz; Amaro, J. E.; Barbaro, M. B.; De Pace, A.; Caballero, J. A.; Megias, G. D.; Donnelly, T. W.</p> <p>2016-11-01</p> <p>We use a relativistic model of meson-<span class="hlt">exchange</span> currents to compute the proton-neutron and proton-proton yields in (e ,e') scattering from 12C in the 2p-2h channel. We compute the response functions and cross section with the relativistic Fermi gas model for a range of kinematics from intermediate- to high-momentum transfers. We find a large contribution of neutron-proton configurations in the initial state, as compared to proton-proton pairs. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-<span class="hlt">exchange</span> currents, mainly by the Δ isobar current. We also analyze the effect of the <span class="hlt">exchange</span> contribution and show that the direct-<span class="hlt">exchange</span> interference strongly affects the determination of the n p /p p ratio.</p> </li> <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('https://www.ncbi.nlm.nih.gov/pubmed/22366186','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22366186"><span id="translatedtitle">Intracellular pH regulation by Na⁺/H⁺ <span class="hlt">exchanger</span>-1 (NHE1) is required for growth factor-<span class="hlt">induced</span> mammary branching morphogenesis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jenkins, Edmund C; Debnath, Shawon; Gundry, Stephen; Gundry, Sajini; Uyar, Umit; Fata, Jimmie E</p> <p>2012-05-01</p> <p>Regulation of intracellular pH (pHi) and protection against cytosolic acidification is primarily a function of the ubiquitous plasma membrane Na+/H+<span class="hlt">exchanger</span>-1 (NHE1), which uses a highly conserved process to transfer cytosolic hydrogen ions (H+) across plasma membranes in <span class="hlt">exchange</span> for extracellular sodium ions (Na+). Growth factors, which are essential regulators of morphogenesis, have also been found to be key activators of NHE1 <span class="hlt">exchanger</span> activity; however, the crosstalk between both has not been fully evaluated during organ development. Here we report that mammary branching morphogenesis <span class="hlt">induced</span> by transforming growth factor-alpha (TGFα) requires PI3K-dependent NHE1-activation and subsequent pHi alkalization. Inhibiting NHE1 activity after TGFα stimulation with 10 μM of the NHE1-specific inhibitor N-Methyl-N-isobutyl Amiloride (MIA) dramatically disrupted branching morphogenesis, <span class="hlt">induced</span> extensive proliferation, ectopic expression of the epithelial hyper-proliferative marker Keratin-6 and sustained activation of MAPK. Together these findings indicate a novel developmental signaling cascade involving TGFα>PI3K>NHE1>pHi alkalization, which leads to a permissible environment for MAPK negative feedback inhibition and thus regulated mammary branching morphogenesis.</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.osti.gov/scitech/biblio/22273941','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22273941"><span id="translatedtitle"><span class="hlt">Exchange</span> bias <span class="hlt">induced</span> by the fully strained La{sub 2/3}Ca{sub 1/3}MnO{sub 3} dead layers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xie, Q. Y.; Wu, X. S.; Gao, J.; Jia, Q. J.</p> <p>2014-05-07</p> <p>A pure compressively strained La{sub 2/3}Ca{sub 1/3}MnO{sub 3} (LCMO) dead layer grown on (001)-oriented LaAlO{sub 3} substrate can show all the rich phenomenon of large bias field shift, coercive field enhancement, and high blocking temperature. The obtained <span class="hlt">exchange</span> bias field (∼350 Oe) and the enhanced coercivity of about 1160 Oe at 5 K under 500 Oe cooling field are superior to that have been reported in LCMO-based ferromagnetic/antiferromagnetic superlattices or nanoscale systems. Our results clearly demonstrate that the inhomogeneous magnetic dead layer of LCMO can <span class="hlt">induce</span> a strong <span class="hlt">exchange</span> bias effect, which may be exploited as a very simple structure for spin-valve device application.</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('http://adsabs.harvard.edu/abs/2017ApPhL.110j2403W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.110j2403W"><span id="translatedtitle">Charge transfer-<span class="hlt">induced</span> magnetic <span class="hlt">exchange</span> bias and electron localization in (111)- and (001)-oriented LaNiO3/LaMnO3 superlattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Haoming; Barzola-Quiquia, Jose Luis; Yang, Chang; Patzig, Christian; Höche, Thomas; Esquinazi, Pablo; Grundmann, Marius; Lorenz, Michael</p> <p>2017-03-01</p> <p>High-quality lattice-matched LaNiO3/LaMnO3 superlattices with monolayer terrace structure have been grown on both (111)- and (001)-oriented SrTiO3 substrates by pulsed laser deposition. In contrast to the previously reported experiments, a magnetic <span class="hlt">exchange</span> bias is observed that reproducibly occurs in both (111)- and (001)-oriented superlattices with the thin single layers of 5 and 7 unit cells, respectively. The <span class="hlt">exchange</span> bias is theoretically explained by charge transfer-<span class="hlt">induced</span> magnetic moments at Ni atoms. Furthermore, magnetization data at low temperature suggest two magnetic phases in the superlattices, with Néel temperature around 10 K. Electrical transport measurements reveal a metal-insulator transition with strong localization of electrons in the superlattices with the thin LaNiO3 layers of 4 unit cells, in which the electrical transport is dominated by two-dimensional variable range hopping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22416178','SCIGOV-STC'); return false;" href="https://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> </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://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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=312743','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=312743"><span id="translatedtitle">SWITCH1 (SWI1): a novel protein required for the establishment of sister <span class="hlt">chromatid</span> cohesion and for bivalent formation at 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>Mercier, Raphaël; Vezon, Daniel; Bullier, Erika; Motamayor, Juan C.; Sellier, Aurélie; Lefèvre, François; Pelletier, Georges; Horlow, Christine</p> <p>2001-01-01</p> <p>We have characterized a new gene, SWI1, involved in sister <span class="hlt">chromatid</span> cohesion during both male and female meiosis in Arabidopsis thaliana. A first allele, swi1.1, was obtained as a T-DNA tagged mutant and was described previously as abnormal exclusively in female meiosis. We have isolated a new allele, swi1.2, which is defective for both male and female meiosis. In swi1.2 male meiosis, the classical steps of prophase were not observed, especially because homologs do not synapse. <span class="hlt">Chromatid</span> arms and centromeres lost their cohesion in a stepwise manner before metaphase I, and 20 <span class="hlt">chromatids</span> instead of five bivalents were seen at the metaphase plate, which was followed by an aberrant segregation. In contrast, swi1.2 female meiocytes performed a mitotic-like division instead of meiosis, indicating a distinct role for SWI1 or a different effect of the loss of SWI1 function in both processes. The SWI1 gene was cloned; the putative SWI1 protein did not show strong similarity to any known protein. Plants transformed with a SWI1–GFP fusion indicated that SWI1 protein is present in meiocyte nuclei, before meiosis and at a very early stage of prophase. Thus, SWI1 appears to be a novel protein involved in <span class="hlt">chromatid</span> cohesion establishment and in chromosome structure during meiosis, but with clear differences between male and female meiosis. PMID:11459834</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26623927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26623927"><span id="translatedtitle">Peroxisome proliferator-activated receptor alpha 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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Cheng-Hsien; Chen, Tso-Hsiao; Wu, Mei-Yi; Chen, Jia-Rung; Tsai, Hwei-Fang; Hong, Li-Yu; Zheng, Cai-Mei; Chiu, I-Jen; Lin, Yuh-Feng; Hsu, Yung-Ho</p> <p>2015-11-23</p> <p>Peroxisome proliferator-activated receptor alpha (PPARα) is a transcription factor which 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> 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 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 pro-survival 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22036860','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22036860"><span id="translatedtitle">Interface roughness <span class="hlt">induced</span> asymmetric magnetic property in sputter-deposited Co/CoO/Co <span class="hlt">exchange</span> coupled trilayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, J.; Sannomiya, T.; Shi, J.; Nakamura, Y.</p> <p>2012-04-01</p> <p>The effect of interface roughness on magnetic properties of <span class="hlt">exchange</span> coupled polycrystalline Co/CoO(t{sub AF})/Co trilayers has been investigated by varying antiferromagnetic layer (CoO) thickness. It has been found that the upper CoO/Co interface becomes rougher with increasing CoO layer thickness, resulting in stronger <span class="hlt">exchange</span> bias of the upper interface than the lower one. The interfacial <span class="hlt">exchange</span> coupling is strengthened by the increase of defect-generated uncompensated antiferromagnetic spins; such spins form coupling with spins in the Co layer at the interface. As a result, the CoO layer thickness dependence of <span class="hlt">exchange</span> bias is much enhanced for the upper Co layer. The transition from anisotropic magnetoresistance to isotropic magnetoresistance for the top Co layer has also been found. This could be attributed to the defects, probably partial thin oxide layers, between Co grains in the top Co layer that leads a switch from spin-orbit scattering related magnetoresistance to spin-dependent electron scattering dominated magnetoresistance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7235798','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7235798"><span id="translatedtitle">Dimethylarsenic acid <span class="hlt">induces</span> tetraploids in Chinese hamster cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Endo, Ginji; Horiguchi, Shun'ichi ); Kuroda, Koichi; Okamoto, Akiyoshi )</p> <p>1992-01-01</p> <p>Arsenic has been documented as a human carcinogen of the skin and lungs. However, attempts to <span class="hlt">induce</span> tumors in experimental animals with inorganoarsenic compounds have mostly failed except in a few studies in which animals were given arsenic trioxide by intratracheal instillation. Moreover, inorganoarsenics are either inactive or too weak to <span class="hlt">induce</span> gene mutations in vitro. The mechanism of arsenic carcinogenicity has not yet been discovered. Most mammals including human are able to methylate inorganoarsenic compounds to methylarsonic acid and dimethylarsenic acid. However, the genotoxicity of organoarsenic compounds has hardly been examined. The authors therefore decided to study this genotoxicity, including the frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) of nine organic and three inorganic arsenic compounds. Observation of the metaphases in the SCE test revealed that only DMA of the organo- and inorgano-arsenic compounds <span class="hlt">induces</span> tetraploids and mitotic arrest. This indicates that the role of DMA may be important in arsenic genotoxicity and may give a clue to the carcinogenic mechanism of arsenic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26477560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26477560"><span id="translatedtitle">Selective <span class="hlt">chromatid</span> segregation mechanism proposed for the human split hand/foot malformation development by chromosome 2 translocations: A perspective.</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>2015-12-01</p> <p>Three unrelated chromosome 2q14.1-14.2 region translocations caused the split hand/foot limb malformation development in humans by an unknown mechanism. Their etiology was described by the autosomal dominant inheritance with incomplete penetrance genetic model although authors stated, "the understanding of the genotype-to-phenotype relationship has been most challenging". The conundrums are that no mutation was found in known genes located at or near the translocation breakpoints, some limbs were malformed while others were not in the same patient and surprisingly breakpoints lie at relatively large distance of more than 2.5 million bases to have caused disorder-causing gene mutations in a single gene. To help understand translocations etiology for limb development, we invoke the selective DNA strand/<span class="hlt">chromatid</span>-specific epigenetic imprinting and segregation mechanism employed by the two highly diverged fission yeasts to produce daughter cells of different cell types by mitosis. By this mechanism, an anterior- and posterior-limb-tissues-generating pair of daughter cells is produced by a single deterministic cell dividing in the anlagen of the limb bud. Accordingly, malformation develops simply because translocations hinder the proper distribution of <span class="hlt">chromatid</span>-specific epialleles of a limb developmental gene during the deterministic cell's mitosis. It is tempting to speculate that such a mechanism might involve the HOXD-cluster genes situated centromere-distal to the translocation breakpoints many million bases away at the 2q31.1 region. Further genetic tests of the hypothesis are proposed for the human and mouse limb development. In sum, genetic analysis of translocations suggests that the sequence asymmetry of strands in the double-helical DNA structure of a developmental gene forms the physical basis of daughter cells' developmental asymmetry, thus opposing the morphogen-gradient research paradigm of limb development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21887327','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21887327"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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 Ca(2+) and apoptosis. However, ethylisopropyl-amiloride (EIPA), a selective inhibitor of NHE, prevented Na(+), K(+) and Ca(2+) 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7738406','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7738406"><span id="translatedtitle">Frequencies of complex chromosome <span class="hlt">exchange</span> aberrations <span class="hlt">induced</span> by 238Pu alpha-particles and detected by fluorescence in situ hybridization using single chromosome-specific probes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Griffin, C S; Marsden, S J; Stevens, D L; Simpson, P; Savage, J R</p> <p>1995-04-01</p> <p>We undertook an analysis of chromosome-type <span class="hlt">exchange</span> aberrations <span class="hlt">induced</span> by alpha-particles using fluorescence in situ hybridization (FISH) with whole chromosome-specific probes for human chromosomes 1 or 4, together with a pan-centromeric probe. Contact-inhibited primary human fibroblasts (in G1) were irradiated with 0.41-1.00 Gy 238Pu alpha-particles and aberrations were analysed at the next mitosis following a single chromosome paint. <span class="hlt">Exchange</span> and aberration painting patterns were classified according to Savage and Simpson (1994a). Of <span class="hlt">exchange</span> aberrations, 38-47% were found to be complex derived, i.e. resulting from three or more breaks in two or more chromosomes, and the variation with dose was minimal. The class of complex aberrations most frequently observed were insertions, derived from a minimum of three breaks in two chromosomes. There was also an elevated frequency of rings. The high level of complex aberrations observed after alpha-particle irradiation indicates that, when chromosome domains are traversed by high linear energy transfer alpha-particle tracks, there is an enhanced probability of production of multiple localized double-strand breaks leading to more complicated interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001REDS..155..415R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001REDS..155..415R"><span id="translatedtitle">Hydrogen-deuterium <span class="hlt">exchange</span> <span class="hlt">induced</span> by an electric field in α-Al2O3 single crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramírez, R.; Colera, I.; Gonz&Ález, R.; Savoini, B.; Chen, Y.</p> <p></p> <p>Hydrogen and deuterium are observed in α-Al2O3 crystals in the form of OH- and OD- radicals, respectively, which absorb in the infrared region. Infrared-absorption measurements were used to monitor diffusion of deuterons and protons in α-Al2O3 single crystals under the application of a moderate electric field parallel to the crystallographic c-axis, in the temperature range of 973-1333K. A linear dependence of the percent of <span class="hlt">exchange</span> with both annealing time and applied voltage is observed, indicating that ionic conduction was taking place. The activation energy for the H+ ↔; D+ <span class="hlt">exchange</span> was determined to be 2.4 eV, less than half the value obtained by pure thermal means, suggesting that under the application of an electric field the deuteron (proton) diffusion mechanism is different.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2712990','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2712990"><span id="translatedtitle">Ca2+ signaling evoked by activation of Na+ channels and Na+/Ca2+ <span class="hlt">exchangers</span> is required for GABA-<span class="hlt">induced</span> NG2 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>Tong, Xiao-ping; Li, Xiang-yao; Zhou, Bing; Shen, Wanhua; Zhang, Zhi-jun; Xu, Tian-le</p> <p>2009-01-01</p> <p>NG2 cells originate from various brain regions and migrate to their destinations during early development. These cells express voltage-gated Na+ channels but fail to produce typical action potentials. The physiological role of Na+ channels in these cells is unclear. We found that GABA <span class="hlt">induces</span> membrane depolarization and Ca2+ elevation in NG2 cells, a process requiring activation of GABAA receptors, Na+ channels, and Na+/Ca2+ <span class="hlt">exchangers</span> (NCXs), but not Ca2+ channels. We have identified a persistent Na+ current in these cells that may underlie the GABA-<span class="hlt">induced</span> pathway of prolonged Na+ elevation, which in turn triggers Ca2+ influx via NCXs. This unique Ca2+ signaling pathway is further shown to be involved in the migration of NG2 cells. Thus, GABAergic signaling mediated by sequential activation of GABAA receptors, noninactivating Na+ channels, and NCXs may play an important role in the development and function of NG2 glial cells in the brain. PMID:19596850</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1240279','SCIGOV-STC'); return false;" href="https://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.osti.gov/pages/biblio/1210146-exchange-bias-effect-au-fe3o4-dumbbell-nanoparticles-induced-charge-transfer-from-gold','SCIGOV-DOEP'); return false;" href="https://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 PAGES</a></p> <p>Feygenson, Mikhail; Bauer, John C; Gai, Zheng; ...</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://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('http://adsabs.harvard.edu/abs/2012JChPh.137e4503N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137e4503N"><span id="translatedtitle">Nuclear magnetic relaxation <span class="hlt">induced</span> by <span class="hlt">exchange</span>-mediated orientational randomization: Longitudinal relaxation dispersion for spin I = 1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nilsson, Tomas; Halle, Bertil</p> <p>2012-08-01</p> <p>The frequency dependence of the longitudinal relaxation rate, known as the magnetic relaxation dispersion (MRD), can provide a frequency-resolved characterization of molecular motions in complex biological and colloidal systems on time scales ranging from 1 ns to 100 μs. The conformational dynamics of immobilized proteins and other biopolymers can thus be probed in vitro or in vivo by exploiting internal water molecules or labile hydrogens that <span class="hlt">exchange</span> with a dominant bulk water pool. Numerous water 1H and 2H MRD studies of such systems have been reported, but the widely different theoretical models currently used to analyze the MRD data have resulted in divergent views of the underlying molecular motions. We have argued that the essential mechanism responsible for the main dispersion is the <span class="hlt">exchange</span>-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings when internal water molecules or labile hydrogens escape from orientationally confining macromolecular sites. In the EMOR model, the <span class="hlt">exchange</span> process is thus not just a means of mixing spin populations but it is also the direct cause of spin relaxation. Although the EMOR theory has been used in several studies to analyze water 2H MRD data from immobilized biopolymers, the fully developed theory has not been described. Here, we present a comprehensive account of a generalized version of the EMOR theory for spin I = 1 nuclides like 2H. As compared to a previously described version of the EMOR theory, the present version incorporates three generalizations that are all essential in applications to experimental data: (i) a biaxial (residual) electric field gradient tensor, (ii) direct and indirect effects of internal motions, and (iii) multiple sites with different <span class="hlt">exchange</span> rates. In addition, we describe and assess different approximations to the exact EMOR theory that are useful in various regimes. In particular, we consider the experimentally important</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22894360','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22894360"><span id="translatedtitle">Nuclear magnetic relaxation <span class="hlt">induced</span> by <span class="hlt">exchange</span>-mediated orientational randomization: longitudinal relaxation dispersion for spin I = 1.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nilsson, Tomas; Halle, Bertil</p> <p>2012-08-07</p> <p>The frequency dependence of the longitudinal relaxation rate, known as the magnetic relaxation dispersion (MRD), can provide a frequency-resolved characterization of molecular motions in complex biological and colloidal systems on time scales ranging from 1 ns to 100 μs. The conformational dynamics of immobilized proteins and other biopolymers can thus be probed in vitro or in vivo by exploiting internal water molecules or labile hydrogens that <span class="hlt">exchange</span> with a dominant bulk water pool. Numerous water (1)H and (2)H MRD studies of such systems have been reported, but the widely different theoretical models currently used to analyze the MRD data have resulted in divergent views of the underlying molecular motions. We have argued that the essential mechanism responsible for the main dispersion is the <span class="hlt">exchange</span>-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings when internal water molecules or labile hydrogens escape from orientationally confining macromolecular sites. In the EMOR model, the <span class="hlt">exchange</span> process is thus not just a means of mixing spin populations but it is also the direct cause of spin relaxation. Although the EMOR theory has been used in several studies to analyze water (2)H MRD data from immobilized biopolymers, the fully developed theory has not been described. Here, we present a comprehensive account of a generalized version of the EMOR theory for spin I = 1 nuclides like (2)H. As compared to a previously described version of the EMOR theory, the present version incorporates three generalizations that are all essential in applications to experimental data: (i) a biaxial (residual) electric field gradient tensor, (ii) direct and indirect effects of internal motions, and (iii) multiple sites with different <span class="hlt">exchange</span> rates. In addition, we describe and assess different approximations to the exact EMOR theory that are useful in various regimes. In particular, we consider the experimentally</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21143909','SCIGOV-STC'); return false;" href="https://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=5182059','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5182059"><span id="translatedtitle">Ric-8A, a G protein chaperone with nucleotide <span class="hlt">exchange</span> activity <span class="hlt">induces</span> long-range secondary structure changes in Gα</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kant, Ravi; Zeng, Baisen; Thomas, Celestine J; Bothner, Brian; Sprang, Stephen R</p> <p>2016-01-01</p> <p>Cytosolic Ric-8A has guanine nucleotide <span class="hlt">exchange</span> factor (GEF) activity and is a chaperone for several classes of heterotrimeric G protein α subunits in vertebrates. Using Hydrogen-Deuterium <span class="hlt">Exchange</span>-Mass Spectrometry (HDX-MS) we show that Ric-8A disrupts the secondary structure of the Gα Ras-like domain that girds the guanine nucleotide-binding site, and destabilizes the interface between the Gαi1 Ras and helical domains, allowing domain separation and nucleotide release. These changes are largely reversed upon binding GTP and dissociation of Ric-8A. HDX-MS identifies a potential Gα interaction site in Ric-8A. Alanine scanning reveals residues crucial for GEF activity within that sequence. HDX confirms that, like G protein-coupled receptors (GPCRs), Ric-8A binds the C-terminus of Gα. In contrast to GPCRs, Ric-8A interacts with Switches I and II of Gα and possibly at the Gα domain interface. These extensive interactions provide both allosteric and direct catalysis of GDP unbinding and release and GTP binding. DOI: http://dx.doi.org/10.7554/eLife.19238.001 PMID:28008853</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28008853','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28008853"><span id="translatedtitle">Ric-8A, a G protein chaperone with nucleotide <span class="hlt">exchange</span> activity <span class="hlt">induces</span> long-range secondary structure changes in Gα.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kant, Ravi; Zeng, Baisen; Thomas, Celestine J; Bothner, Brian; Sprang, Stephen R</p> <p>2016-12-23</p> <p>Cytosolic Ric-8A has guanine nucleotide <span class="hlt">exchange</span> factor (GEF) activity and is a chaperone for several classes of heterotrimeric G protein α subunits in vertebrates. Using Hydrogen-Deuterium <span class="hlt">Exchange</span>-Mass Spectrometry (HDX-MS) we show that Ric-8A disrupts the secondary structure of the Gα Ras-like domain that girds the guanine nucleotide-binding site, and destabilizes the interface between the Gαi1 Ras and helical domains, allowing domain separation and nucleotide release. These changes are largely reversed upon binding GTP and dissociation of Ric-8A. HDX-MS identifies a potential Gα interaction site in Ric-8A. Alanine scanning reveals residues crucial for GEF activity within that sequence. HDX confirms that, like G protein-coupled receptors (GPCRs), Ric-8A binds the C-terminus of Gα. In contrast to GPCRs, Ric-8A interacts with Switches I and II of Gα and possibly at the Gα domain interface. These extensive interactions provide both allosteric and direct catalysis of GDP unbinding and release and GTP binding.</p> </li> <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> </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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3540932','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3540932"><span id="translatedtitle">Left-right symmetry breaking in mice by left-right dynein may occur via a biased <span class="hlt">chromatid</span> segregation mechanism, without directly involving the Nodal gene</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sauer, Stephan; Klar, Amar J. S.</p> <p>2012-01-01</p> <p>Ever since cloning the classic iv (inversed viscerum) mutation identified the “left-right dynein” (lrd) gene in mice, most research on body laterality determination has focused on its function in motile cilia at the node embryonic organizer. This model is attractive, as it links chirality of cilia architecture to asymmetry development. However, lrd is also expressed in blastocysts and embryonic stem cells, where it was shown to bias the segregation of recombined sister <span class="hlt">chromatids</span> away from each other in mitosis. These data suggested that lrd is part of a cellular mechanism that recognizes and selectively segregates sister <span class="hlt">chromatids</span> based on their replication history: old “Watson” versus old “Crick” strands. We previously proposed that the mouse left-right axis is established via an asymmetric cell division prior to/or during gastrulation. In this model, left-right dynein selectively segregates epigenetically differentiated sister <span class="hlt">chromatids</span> harboring a hypothetical “left-right axis development 1” (“lra1”) gene during the left-right axis establishing cell division. Here, asymmetry development would be ultimately governed by the chirality of the cytoskeleton and the DNA molecule. Our model predicts that randomization of <span class="hlt">chromatid</span> segregation in lrd mutants should produce embryos with 25% situs solitus, 25% situs inversus, and 50% embryonic death due to heterotaxia and isomerism. Here we confirmed this prediction by using two distinct lrd mutant alleles. Other than lrd, thus far Nodal gene is the most upstream function implicated in visceral organs laterality determination. We next tested whether the Nodal gene constitutes the lra1 gene hypothesized in the model by testing mutant’s effect on 50% embryonic lethality observed in lrd mutants. Since Nodal mutation did not suppress lethality, we conclude that Nodal is not equivalent to the lra1 gene. In summary, we describe the origin of 50% lethality in lrd mutant mice not yet explained by any other</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23316472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23316472"><span id="translatedtitle">Left-right symmetry breaking in mice by left-right dynein may occur via a biased <span class="hlt">chromatid</span> segregation mechanism, without directly involving the Nodal gene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sauer, Stephan; Klar, Amar J S</p> <p>2012-01-01</p> <p>Ever since cloning the classic iv (inversedviscerum) mutation identified the "left-right dynein" (lrd) gene in mice, most research on body laterality determination has focused on its function in motile cilia at the node embryonic organizer. This model is attractive, as it links chirality of cilia architecture to asymmetry development. However, lrd is also expressed in blastocysts and embryonic stem cells, where it was shown to bias the segregation of recombined sister <span class="hlt">chromatids</span> away from each other in mitosis. These data suggested that lrd is part of a cellular mechanism that recognizes and selectively segregates sister <span class="hlt">chromatids</span> based on their replication history: old "Watson" versus old "Crick" strands. We previously proposed that the mouse left-right axis is established via an asymmetric cell division prior to/or during gastrulation. In this model, left-right dynein selectively segregates epigenetically differentiated sister <span class="hlt">chromatids</span> harboring a hypothetical "left-right axis development 1" ("lra1") gene during the left-right axis establishing cell division. Here, asymmetry development would be ultimately governed by the chirality of the cytoskeleton and the DNA molecule. Our model predicts that randomization of <span class="hlt">chromatid</span> segregation in lrd mutants should produce embryos with 25% situs solitus, 25% situs inversus, and 50% embryonic death due to heterotaxia and isomerism. Here we confirmed this prediction by using two distinct lrd mutant alleles. Other than lrd, thus far Nodal gene is the most upstream function implicated in visceral organs laterality determination. We next tested whether the Nodal gene constitutes the lra1 gene hypothesized in the model by testing mutant's effect on 50% embryonic lethality observed in lrd mutants. Since Nodal mutation did not suppress lethality, we conclude that Nodal is not equivalent to the lra1 gene. In summary, we describe the origin of 50% lethality in lrd mutant mice not yet explained by any other laterality</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3834830','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3834830"><span id="translatedtitle">Homology-mediated end-capping as a primary step of sister <span class="hlt">chromatid</span> fusion in the breakage-fusion-bridge cycles</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marotta, Michael; Chen, Xiongfong; Watanabe, Takaaki; Faber, Pieter W.; Diede, Scott J.; Tapscott, Stephen; Tubbs, Raymond; Kondratova, Anna; Stephens, Robert; Tanaka, Hisashi</p> <p>2013-01-01</p> <p>Breakage-fusion-bridge (BFB) cycle is a series of chromosome breaks and duplications that could lead to the increased copy number of a genomic segment (gene amplification). A critical step of BFB cycles leading to gene amplification is a palindromic fusion of sister <span class="hlt">chromatids</span> following the rupture of a dicentric chromosome during mitosis. It is currently unknown how sister <span class="hlt">chromatid</span> fusion is produced from a mitotic break. To delineate the process, we took an integrated genomic, cytogenetic and molecular approach for the recurrent MCL1 amplicon at chromosome 1 in human tumor cells. A newly developed next-generation sequencing-based approach identified a cluster of palindromic fusions within the amplicon at ∼50-kb intervals, indicating a series of breaks and fusions by BFB cycles. The physical location of the amplicon (at the end of a broken chromosome) further indicated BFB cycles as underlying processes. Three palindromic fusions were mediated by the homologies between two nearby inverted Alu repeats, whereas the other two fusions exhibited microhomology-mediated events. Such breakpoint sequences indicate that homology-mediated fold-back capping of broken ends followed by DNA replication is an underlying mechanism of sister <span class="hlt">chromatid</span> fusion. Our results elucidate nucleotide-level events during BFB cycles and end processing for naturally occurring mitotic breaks. PMID:23975201</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/975402','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/975402"><span id="translatedtitle"><span class="hlt">Exchange-Induced</span> Negative-U Charge Order in N-Doped WO3: A Spin-Peierls-Like System</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Huda, M. N.; Yan, Y.; Wei, S.-H.; Al-Jassim, M. M.</p> <p>2009-01-01</p> <p>An unconventional spin-Peierls-type distortion was found in a nonmagnetic atom N doped pseudo-one-dimensional WO{sub 3} system. The periodicity of the initial ferromagnetic WO{sub 3}:N is doubled in one direction, and the band gap opens up due to this distortion. The magnetic moment at the N site is asymmetric in the distorted system, and the interaction between the localized spin is very weak. We show that the large <span class="hlt">exchange</span> interaction of the nitrogen 2p atomic orbital and the pseudo-one-dimensional W-O-W chain in monoclinic WO{sub 3} structure is the origin of this spin-Peierls-like transition that leads to the stabilization of an unusual negative-U charge-ordered system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSSCh.246...23W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSSCh.246...23W"><span id="translatedtitle">Metal-ion <span class="hlt">exchange</span> <span class="hlt">induced</span> structural transformation as a way of forming novel Ni(II)- and Cu(II)-salicylaldimine structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Jing-Yun; Tsai, Chi-Jou; Chang, Ching-Yun; Wu, Yung-Yuan</p> <p>2017-02-01</p> <p>A Zn(II)-salicylaldimine complex [Zn(Lsalpyca)(H2O)]n (1, where H2Lsalpyca=4-hydroxy-3-(((pyridin-2-yl)methylimino)methyl)benzoic acid), with a one-dimensional (1D) chain structure, has been successfully converted to a discrete Ni(II)-salicylaldimine complex [Ni(Lsalpyca)(H2O)3] (2) and an infinite Cu(II)-salicylaldimine complex {[Cu(Lsalpyca)]·3H2O}n (3) through a metal-ion <span class="hlt">exchange</span> <span class="hlt">induced</span> structural transformation process. However, such processes do not worked by Mn(II) and Co(II) ions. Solid-state structure analyses reveal that complexes 1-3 form comparable coordinative or supramolecular zigzag chains running along the crystallographic [201] direction. In addition, replacing Zn(II) ion by Ni(II) and Cu(II) ions caused changes in coordination environment and sphere of metal centers, from a 5-coordinate intermediate geometry of square pyramidal and trigonal bipyramidal in 1 to a 6-coordinate octahedral geometry in 2, and to a 4-coordiante square planar geometry in 3. This study shows that metal-ion <span class="hlt">exchange</span> serves as a very efficient way of forming new coordination complexes that may not be obtained through direct synthesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5325406','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5325406"><span id="translatedtitle">Essential role of Na+/Ca2+ <span class="hlt">exchanger</span> 1 in smoking-<span class="hlt">induced</span> growth and migration of esophageal squamous cell carcinoma</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Tao; Qi, Ximing; Zhao, Min; Xuan, Bin; Meng, Xiangcai; Guo, Yunsheng; Liu, Qingbin; Liang, Huagang; Li, Yang; Dong, Hui; Wang, Yimin</p> <p>2016-01-01</p> <p>Tobacco-derived carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a major environmental risk factor for the pathogenesis of human esophageal squamous cell carcinoma (ESCC). However, the molecular mechanisms by which tobacco <span class="hlt">induces</span> ESCC are not well understood. Na+/Ca2+ <span class="hlt">exchanger</span> 1 (NCX1) is a plasma membrane transporter protein that plays an essential role in maintaining cytosolic Ca2+ ([Ca2+]cyt) homeostasis under physiological conditions and is implicated in tumorigenesis as well. In this study, we found that NCX1 expression was significantly higher in ESCC primary tissues compared to the noncancerous tissues and was overexpressed in tumor samples from the smoking patients. The expression of NCX1 proteins was also significantly higher in human ESCC cell lines compared to normal esophageal epithelial cell line. Moreover, NNK potentiated the [Ca2+]cyt signaling <span class="hlt">induced</span> by removal of extracellular Na+, which was abolished by KB-R7943 or SN-6. NNK dose-dependently promoted proliferation and migration of human ESCC cells <span class="hlt">induced</span> by NCX1 activation. Therefore, NCX1 expression correlates with the smoking status of ESCC patients, and NNK activates the Ca2+ entry mode of NCX1 in ESCC cells, leading to cell proliferation and migration. Our findings suggest NCX1 protein is a novel potential target for ESCC therapy. PMID:27588478</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646195','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646195"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rajendran, Vazhaikkurichi M.; Nanda Kumar, Navalpur S.; Tse, Chung M.; Binder, Henry J.</p> <p>2015-01-01</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. PMID:26350456</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25257309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25257309"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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>2014-11-18</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15509707','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15509707"><span id="translatedtitle">Hoechst 33342 stain and u.v. laser exposure do not <span class="hlt">induce</span> genotoxic effects in flow-sorted boar spermatozoa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Parrilla, I; Vázquez, J M; Cuello, C; Gil, M A; Roca, J; Di Berardino, D; Martínez, E A</p> <p>2004-11-01</p> <p>Sex selection by flow cytometry/cell sorting involves the staining of spermatozoa with Hoechst 33342 in combination with the impact of a u.v. laser beam, two potentially mutagenic agents. A phenotypic and cytogenetic study of lymphocytes of piglets born after insemination with spermatozoa stained with Hoechst 33342 and from piglets obtained from stain-sorted spermatozoa was performed to evaluate the genotoxic effect of Hoechst 33342 staining and u.v. laser irradiation on the offspring. Lymphocytes from piglets born after insemination with unstained spermatozoa, but from the same ejaculate, were used as a control group. Peripheral blood lymphocytes from these piglets were cultured following a standard cell culture protocol. Cells were then collected by centrifugation, subjected to hypotonic solution and fixed and dropped onto slides. Sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) and chromosome aberrations (CAs: including chromosome and <span class="hlt">chromatid</span> breaks) per cell were scored in 50-s division metaphase spreads from each donor. Reproductive parameters and litter performance of all inseminations performed were also recorded in all groups. Data were analyzed by ANOVA. No significant increase (P > 0.05) of SCE and CA frequencies were observed in piglets born from stained spermatozoa or from stain-sorted spermatozoa with respect to controls (untreated sperm). The results indicated that no mutagenic effect on spermatozoa, expressed as increases in the incidence of abnormalities in the resulting offspring and also as increases in SCE and CA frequencies on lymphocytes from these individuals, was <span class="hlt">induced</span> by the staining of boar spermatozoa with Hoechst 33342, nor by combination of staining with laser impact during flow cytometry.</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.osti.gov/scitech/biblio/5734773','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5734773"><span id="translatedtitle">Correction of enhanced Na(+)-H+ <span class="hlt">exchange</span> of rat small intestinal brush-border membranes in streptozotocin-<span class="hlt">induced</span> diabetes by insulin or 1,25-dihydroxycholecalciferol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dudeja, P.K.; Wali, R.K.; Klitzke, A.; Sitrin, M.D.; Brasitus, T.A. )</p> <p>1991-05-01</p> <p>Diabetes was <span class="hlt">induced</span> in rats by administration of a single i.p. injection of streptozotocin (50 mg/kg body wt). After 7 d, diabetic rats were further treated with insulin or 1,25-dihydroxycholecalciferol (1,25(OH)2D3) for an additional 5-7 d. Control, diabetic, diabetic + insulin, and diabetic + 1,25(OH)2D3 rats were then killed, their proximal small intestines were removed, and villus-tip epithelial cells were isolated and used to prepare brush-border membrane vesicles. Preparations from each of these groups were then analyzed and compared with respect to their amiloride-sensitive, electroneutral Na(+)-H+ <span class="hlt">exchange</span> activity, using {sup 22}Na uptake as well as acridine orange techniques. The results of these experiments demonstrated that (a) H+ gradient-dependent {sup 22}Na uptake as well as Na+ gradient-dependent transmembrane H+ fluxes were significantly increased in diabetic vesicles compared to their control counterparts, (b) kinetic studies demonstrated that this enhanced {sup 22}Na uptake in diabetes was a result of increased maximal velocity (Vmax) of this <span class="hlt">exchanger</span> with no change in apparent affinity (Km) for Na+, (c) serum levels of 1,25(OH)2D3 were significantly lower in diabetic animals compared with their control counterparts; and (d) insulin or 1,25(OH)2D3 treatment restored the Vmax alterations to control values, without any significant changes in Km, concomitant with significantly increasing the serum levels of 1,25(OH)2D3 in diabetic animals. These results indicate that Na(+)-H+ activity is significantly increased in proximal small intestinal luminal membranes of streptozotocin-<span class="hlt">induced</span> diabetic rats. Moreover, alterations in the serum levels of 1,25(OH)2D3 may, at least in part, explain this enhanced antiporter activity and its correction by insulin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22402585','SCIGOV-STC'); return false;" href="https://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('https://www.osti.gov/scitech/biblio/6654578','SCIGOV-STC'); return false;" href="https://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/27901091','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27901091"><span id="translatedtitle">Kitaev <span class="hlt">exchange</span> and field-<span class="hlt">induced</span> quantum spin-liquid states in honeycomb α-RuCl3.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yadav, Ravi; Bogdanov, Nikolay A; Katukuri, Vamshi M; Nishimoto, Satoshi; van den Brink, Jeroen; Hozoi, Liviu</p> <p>2016-11-30</p> <p>Large anisotropic <span class="hlt">exchange</span> in 5d and 4d oxides and halides open the door to new types of magnetic ground states and excitations, inconceivable a decade ago. A prominent case is the Kitaev spin liquid, host of remarkable properties such as protection of quantum information and the emergence of Majorana fermions. Here we discuss the promise for spin-liquid behavior in the 4d(5) honeycomb halide α-RuCl3. From advanced electronic-structure calculations, we find that the Kitaev interaction is ferromagnetic, as in 5d(5) iridium honeycomb oxides, and indeed defines the largest superexchange energy scale. A ferromagnetic Kitaev coupling is also supported by a detailed analysis of the field-dependent magnetization. Using exact diagonalization and density-matrix renormalization group techniques for extended Kitaev-Heisenberg spin Hamiltonians, we find indications for a transition from zigzag order to a gapped spin liquid when applying magnetic field. Our results offer a unified picture on recent magnetic and spectroscopic measurements on this material and open new perspectives on the prospect of realizing quantum spin liquids in d(5) halides and oxides in general.</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/2016NatSR...637925Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...637925Y"><span id="translatedtitle">Kitaev <span class="hlt">exchange</span> and field-<span class="hlt">induced</span> quantum spin-liquid states in honeycomb α-RuCl3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yadav, Ravi; Bogdanov, Nikolay A.; Katukuri, Vamshi M.; Nishimoto, Satoshi; van den Brink, Jeroen; Hozoi, Liviu</p> <p>2016-11-01</p> <p>Large anisotropic <span class="hlt">exchange</span> in 5d and 4d oxides and halides open the door to new types of magnetic ground states and excitations, inconceivable a decade ago. A prominent case is the Kitaev spin liquid, host of remarkable properties such as protection of quantum information and the emergence of Majorana fermions. Here we discuss the promise for spin-liquid behavior in the 4d5 honeycomb halide α-RuCl3. From advanced electronic-structure calculations, we find that the Kitaev interaction is ferromagnetic, as in 5d5 iridium honeycomb oxides, and indeed defines the largest superexchange energy scale. A ferromagnetic Kitaev coupling is also supported by a detailed analysis of the field-dependent magnetization. Using exact diagonalization and density-matrix renormalization group techniques for extended Kitaev-Heisenberg spin Hamiltonians, we find indications for a transition from zigzag order to a gapped spin liquid when applying magnetic field. Our results offer a unified picture on recent magnetic and spectroscopic measurements on this material and open new perspectives on the prospect of realizing quantum spin liquids in d5 halides and oxides in general.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26317726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26317726"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Itin, A P; Katsnelson, M I</p> <p>2015-08-14</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5128801','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5128801"><span id="translatedtitle">Kitaev <span class="hlt">exchange</span> and field-<span class="hlt">induced</span> quantum spin-liquid states in honeycomb α-RuCl3</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yadav, Ravi; Bogdanov, Nikolay A.; Katukuri, Vamshi M.; Nishimoto, Satoshi; van den Brink, Jeroen; Hozoi, Liviu</p> <p>2016-01-01</p> <p>Large anisotropic <span class="hlt">exchange</span> in 5d and 4d oxides and halides open the door to new types of magnetic ground states and excitations, inconceivable a decade ago. A prominent case is the Kitaev spin liquid, host of remarkable properties such as protection of quantum information and the emergence of Majorana fermions. Here we discuss the promise for spin-liquid behavior in the 4d5 honeycomb halide α-RuCl3. From advanced electronic-structure calculations, we find that the Kitaev interaction is ferromagnetic, as in 5d5 iridium honeycomb oxides, and indeed defines the largest superexchange energy scale. A ferromagnetic Kitaev coupling is also supported by a detailed analysis of the field-dependent magnetization. Using exact diagonalization and density-matrix renormalization group techniques for extended Kitaev-Heisenberg spin Hamiltonians, we find indications for a transition from zigzag order to a gapped spin liquid when applying magnetic field. Our results offer a unified picture on recent magnetic and spectroscopic measurements on this material and open new perspectives on the prospect of realizing quantum spin liquids in d5 halides and oxides in general. PMID:27901091</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25055824','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25055824"><span id="translatedtitle">Epidermal growth factor-<span class="hlt">induced</span> proliferation of collecting duct cells from Oak Ridge polycystic kidney mice involves activation of Na+/H+ <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>Coaxum, Sonya D; Blanton, Mary G; Joyner, Alisha; Akter, Tanjina; Bell, P Darwin; Luttrell, Louis M; Raymond, John R; Lee, Mi-Hye; Blichmann, Paul A; Garnovskaya, Maria N; Saigusa, Takamitsu</p> <p>2014-09-15</p> <p>Epidermal growth factor (EGF) is linked to the pathogenesis of polycystic kidney disease (PKD). We explored signaling pathways activated by EGF in orpk cilia (-) collecting duct cell line derived from a mouse model of PKD (hypomorph of the Tg737/Ift88 gene) with severely stunted cilia, and in a control orpk cilia (+) cell line with normal cilia. RT-PCR demonstrated mRNAs for EGF receptor subunits ErbB1, ErbB2, ErbB3, ErbB4, and mRNAs for Na(+)/H(+) <span class="hlt">exchangers</span> (NHE), NHE-1, NHE-2, NHE-3, NHE-4, and NHE-5 in both cell lines. EGF stimulated proton efflux in both cell lines. This effect was significantly attenuated by MIA, 5-(n-methyl-N-isobutyl) amiloride, a selective inhibitor of NHE-1 and NHE-2, and orpk cilia (-) cells were more sensitive to MIA than control cells (P < 0.01). EGF significantly <span class="hlt">induced</span> extracellular signal-regulated kinase (ERK) phosphorylation in both cilia (+) and cilia (-) cells (63.3 and 123.6%, respectively), but the effect was more pronounced in orpk cilia (-) cells (P < 0.01). MIA significantly attenuated EGF-<span class="hlt">induced</span> ERK phosphorylation only in orpk cilia (-) cells (P < 0.01). EGF increased proliferation of orpk cilia (+) cells and orpk cilia (-) cells, respectively, and MIA at 1-5 μM attenuated EGF-<span class="hlt">induced</span> proliferation in orpk cilia (-) cells without affecting proliferation of orpk cilia (+) cells. EGF-<span class="hlt">induced</span> proliferation of both cell lines was significantly decreased by the EGFR tyrosine kinase inhibitor AG1478 and MEK inhibitor PD98059. These results suggest that EGF exerts mitogenic effects in the orpk cilia (-) cells via activation of growth-associated amiloride-sensitive NHEs and ERK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17308111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17308111"><span id="translatedtitle">c-Jun NH2-terminal kinase-related Na+/H+ <span class="hlt">exchanger</span> isoform 1 activation controls hexokinase II expression in benzo(a)pyrene-<span class="hlt">induced</span> apoptosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huc, Laurence; Tekpli, Xavier; Holme, Jørn A; Rissel, Mary; Solhaug, Anita; Gardyn, Claire; Le Moigne, Gwénaelle; Gorria, Morgane; Dimanche-Boitrel, Marie-Thérèse; Lagadic-Gossmann, Dominique</p> <p>2007-02-15</p> <p>Regulation of the balance between survival, proliferation, and apoptosis on carcinogenic polycyclic aromatic hydrocarbon (PAH) exposure is still poorly understood and more particularly the role of physiologic variables, including intracellular pH (pH(i)). Although the involvement of the ubiquitous pH(i) regulator Na(+)/H(+) <span class="hlt">exchanger</span> isoform 1 (NHE1) in tumorigenesis is well documented, less is known about its role and regulation during apoptosis. Our previous works have shown the primordial role of NHE1 in carcinogenic PAH-<span class="hlt">induced</span> apoptosis. This alkalinizing transporter was activated by an early CYP1-dependent H(2)O(2) production, subsequently promoting mitochondrial dysfunction leading to apoptosis. The aim of this study was to further elucidate how NHE1 was activated by benzo(a)pyrene (BaP) and what the downstream events were in the context of apoptosis. Our results indicate that the mitogen-activated protein kinase kinase 4/c-Jun NH(2)-terminal kinase (MKK4/JNK) pathway was a link between BaP-<span class="hlt">induced</span> H(2)O(2) production and NHE1 activation. This activation, in combination with BaP-<span class="hlt">induced</span> phosphorylated p53, promoted mitochondrial superoxide anion production, supporting the existence of a common target for NHE1 and p53. Furthermore, we showed that the mitochondrial expression of glycolytic enzyme hexokinase II (HKII) was decreased following a combined action of NHE1 and p53 pathways, thereby enhancing the BaP-<span class="hlt">induced</span> apoptosis. Taken together, our findings suggest that, on BaP exposure, MKK4/JNK targets NHE1 with consequences on HKII protein, which might thus be a key protein during carcinogenic PAH apoptosis.</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/23254329','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23254329"><span id="translatedtitle">Competing roles of DNA end resection and non-homologous end joining functions in the repair of replication-born double-strand breaks by 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>Muñoz-Galván, Sandra; López-Saavedra, Ana; Jackson, Stephen P; Huertas, Pablo; Cortés-Ledesma, Felipe; Aguilera, Andrés</p> <p>2013-02-01</p> <p>While regulating the choice between homologous recombination and non-homologous end joining (NHEJ) as mechanisms of double-strand break (DSB) repair is exerted at several steps, the key step is DNA end resection, which in Saccharomyces cerevisiae is controlled by the MRX complex and the Sgs1 DNA helicase or the Sae2 and Exo1 nucleases. To assay the role of DNA resection in sister-<span class="hlt">chromatid</span> recombination (SCR) as the major repair mechanism of spontaneous DSBs, we used a circular minichromosome system for the repair of replication-born DSBs by SCR in yeast. We provide evidence that MRX, particularly its Mre11 nuclease activity, and Sae2 are required for SCR-mediated repair of DSBs. The phenotype of nuclease-deficient MRX mutants is suppressed by ablation of Yku70 or overexpression of Exo1, suggesting a competition between NHEJ and resection factors for DNA ends arising during replication. In addition, we observe partially redundant roles for Sgs1 and Exo1 in SCR, with a more prominent role for Sgs1. Using human U2OS cells, we also show that the competitive nature of these reactions is likely evolutionarily conserved. These results further our understanding of the role of DNA resection in repair of replication-born DSBs revealing unanticipated differences between these events and repair of enzymatically <span class="hlt">induced</span> DSBs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20590128','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20590128"><span id="translatedtitle">Redox <span class="hlt">exchange</span> <span class="hlt">induced</span> MnO2 nanoparticle enrichment in poly(3,4-ethylenedioxythiophene) nanowires for electrochemical energy storage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Ran; Duay, Jonathon; Lee, Sang Bok</p> <p>2010-07-27</p> <p>MnO2 nanoparticle enriched poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires are fabricated by simply soaking the PEDOT nanowires in potassium permanganate (KMnO4) solution. The structures of these MnO2 nanoparticle enriched PEDOT nanowires are characterized by SEM and TEM, which show that the MnO2 nanoparticles have uniform sizes and are finely dispersed in the PEDOT matrix. The chemical constituents and bonding of these composite nanowires are characterized by energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and infrared spectroscopy, which indicate that the formation and dispersion of these MnO2 nanoparticles into the nanoscale pores of the PEDOT nanowires are most likely triggered by the reduction of KMnO4 via the redox <span class="hlt">exchange</span> of permanganate ions with the functional group on PEDOT. Varying the concentrations of KMnO4 and the reaction time controls the loading amount and size of the MnO2 nanoparticles. Cyclic voltammetry and galvanostatic charge-discharge are used to characterize the electrochemical properties of these MnO2 nanoparticle loaded PEDOT nanowires. Due to their extremely high exposed surface area with nanosizes, the pristine MnO2 nanoparticles in these MnO2 nanoparticle enriched PEDOT nanowires show very high specific capacitance (410 F/g) as the supercapacitor electrode materials as well as high Li+ storage capacity (300 mAh/g) as cathode materials of Li ion battery, which boost the energy storage capacity of PEDOT nanowires to 4 times without causing excessive volume expansion in the polymer. The highly conductive and porous PEDOT matrix facilitates fast charge/discharge of the MnO2 nanoparticles and prevents them from agglomerating. These synergic properties enable the MnO2 nanoparticle enriched PEDOT nanowires to be promising electrode materials for supercapacitors and lithium ion batteries.</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('https://www.epa.gov/exchangenetwork','PESTICIDES'); return false;" href="https://www.epa.gov/exchangenetwork"><span id="translatedtitle"><span class="hlt">Exchange</span> Network</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>The Environmental Information <span class="hlt">Exchange</span> Network (EIEN) is an Internet-based system used by state, tribal and territorial partners to securely share environmental and health information with one another and EPA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/anatomyvideos/000059.htm','SCIGOVIMAGE-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/anatomyvideos/000059.htm"><span id="translatedtitle">Gas <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.nlm.nih.gov/medlineplus/videosandcooltools.html">MedlinePlus Videos and Cool Tools</a></p> <p></p> <p></p> <p>... during exhalation. Gas <span class="hlt">exchange</span> is the delivery of oxygen from the lungs to the bloodstream, and the ... share a membrane with the capillaries in which oxygen and carbon dioxide move freely between the respiratory ...</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('https://www.ncbi.nlm.nih.gov/pubmed/21347277','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21347277"><span id="translatedtitle">New functions of Ctf18-RFC in preserving genome stability outside its role in 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>Gellon, Lionel; Razidlo, David F; Gleeson, Olive; Verra, Lauren; Schulz, Danae; Lahue, Robert S; Freudenreich, Catherine H</p> <p>2011-02-10</p> <p>Expansion of DNA trinucleotide repeats causes at least 15 hereditary neurological diseases, and these repeats also undergo contraction and fragility. Current models to explain this genetic instability invoke erroneous DNA repair or aberrant replication. Here we show that CAG/CTG tracts are stabilized in Saccharomyces cerevisiae by the alternative clamp loader/unloader Ctf18-Dcc1-Ctf8-RFC complex (Ctf18-RFC). Mutants in Ctf18-RFC increased all three forms of triplet repeat instability--expansions, contractions, and fragility--with effect over a wide range of allele lengths from 20-155 repeats. Ctf18-RFC predominated among the three alternative clamp loaders, with mutants in Elg1-RFC or Rad24-RFC having less effect on trinucleotide repeats. Surprisingly, chl1, scc1-73, or scc2-4 mutants defective in sister <span class="hlt">chromatid</span> cohesion (SCC) did not increase instability, suggesting that Ctf18-RFC protects triplet repeats independently of SCC. Instead, three results suggest novel roles for Ctf18-RFC in facilitating genomic stability. First, genetic instability in mutants of Ctf18-RFC was exacerbated by simultaneous deletion of the fork stabilizer Mrc1, but suppressed by deletion of the repair protein Rad52. Second, single-cell analysis showed that mutants in Ctf18-RFC had a slowed S phase and a striking G2/M accumulation, often with an abnormal multi-budded morphology. Third, ctf18 cells exhibit increased Rad52 foci in S phase, often persisting into G2, indicative of high levels of DNA damage. The presence of a repeat tract greatly magnified the ctf18 phenotypes. Together these results indicate that Ctf18-RFC has additional important functions in preserving genome stability, besides its role in SCC, which we propose include lesion bypass by replication forks and post-replication repair.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27151921','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27151921"><span id="translatedtitle">Double Knockout of the Na+-Driven Cl-/HCO3- <span class="hlt">Exchanger</span> and Na+/Cl- Cotransporter <span class="hlt">Induces</span> Hypokalemia and Volume Depletion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sinning, Anne; Radionov, Nikita; Trepiccione, Francesco; López-Cayuqueo, Karen I; Jayat, Maximilien; Baron, Stéphanie; Cornière, Nicolas; Alexander, R Todd; Hadchouel, Juliette; Eladari, Dominique; Hübner, Christian A; Chambrey, Régine</p> <p>2017-01-01</p> <p>We recently described a novel thiazide-sensitive electroneutral NaCl transport mechanism resulting from the parallel operation of the Cl(-)/HCO3(-) <span class="hlt">exchanger</span> pendrin and the Na(+)-driven Cl(-)/2HCO3(-) <span class="hlt">exchanger</span> (NDCBE) in β-intercalated cells of the collecting duct. Although a role for pendrin in maintaining Na(+) balance, intravascular volume, and BP is well supported, there is no in vivo evidence for the role of NDCBE in maintaining Na(+) balance. Here, we show that deletion of NDCBE in mice caused only subtle perturbations of Na(+) homeostasis and provide evidence that the Na(+)/Cl(-) cotransporter (NCC) compensated for the inactivation of NDCBE. To unmask the role of NDCBE, we generated Ndcbe/Ncc double-knockout (dKO) mice. On a normal salt diet, dKO and single-knockout mice exhibited similar activation of the renin-angiotensin-aldosterone system, whereas only dKO mice displayed a lower blood K(+) concentration. Furthermore, dKO mice displayed upregulation of the epithelial sodium channel (ENaC) and the Ca(2+)-activated K(+) channel BKCa. During NaCl depletion, only dKO mice developed marked intravascular volume contraction, despite dramatically increased renin activity. Notably, the increase in aldosterone levels expected on NaCl depletion was attenuated in dKO mice, and single-knockout and dKO mice had similar blood K(+) concentrations under this condition. In conclusion, NDCBE is necessary for maintaining sodium balance and intravascular volume during salt depletion or NCC inactivation in mice. Furthermore, NDCBE has an important role in the prevention of hypokalemia. Because NCC and NDCBE are both thiazide targets, the combined inhibition of NCC and the NDCBE/pendrin system may explain thiazide-<span class="hlt">induced</span> hypokalemia in some patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22676472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22676472"><span id="translatedtitle">Ligand <span class="hlt">exchange</span> <span class="hlt">inducing</span> efficient incorporation of CisPt derivatives into Ureasil-PPO hybrid and their interactions with the multifunctional hybrid network.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Molina, Eduardo F; Pulcinelli, Sandra H; Santilli, Celso V; Briois, Valérie</p> <p>2012-07-12</p> <p>Efficient incorporation of (PtCl3EtOH)(-) anion derived from CisPt moiety into ureasil-PPO (poly(propylene oxide)) network was achieved from one-pot sol-gel synthesis carried out in the presence of water, HCl, and ethanol. Reactant proportion was adequately chosen to lead the sol-gel formation of siloxane nodes at the end of short PPO chains, to prevent the CisPt hydrolysis, and to <span class="hlt">induce</span> platinum ligand <span class="hlt">exchange</span>. The efficient dissolution of Pt species and the formation of a homogeneous liquid-like solution on the transparent and elastomeric ureasil-PPO hybrid were evidenced by differential scanning calorimetry and small-angle X-ray scattering. The CisPt ligand <span class="hlt">exchange</span> and the formation of a Zeise-type salt Y(+)(PtCl3R)(-) were demonstrated by Raman spectroscopy and Pt L3-edge EXAFS analysis. In light of these results and in agreement with the proportion of reactants introduced in the media for synthesis and those self-produced by hydrolysis and condensation processes, we proposed for R the ethanol moiety and for Y the ammonium cation. The Raman spectroscopy studies indicated also that the ammonium cations are coordinated by the ether-type oxygen atoms of the PPO chains backbone, whereas the amine groups of the urea linkage participate in the (PtCl3EtOH)(-) anion coordination. In situ Raman monitoring of Pt species decomplexation <span class="hlt">induced</span> by immersion of hybrid matrix in water highlighted the specific participation of Pt ligands in interaction with the urea group and of NH4(+) cations coordinated by ether-type oxygen atoms in the formation of supramolecular interactions between the PPO chains. The electrospray mass spectrometry analysis of the Pt species released in water from the ureasil-PPO hybrid evidenced that the structure of the complex, NH4 (PtCl3 EtOH), incorporated in the matrix is totally preserved after delivery. Due to both well-known antitumoral and catalytic activities of Pt species, the results reported herein are of prime importance for further</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24911448','PUBMED'); return false;" href="https://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>2014-08-07</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25858142','PUBMED'); return false;" href="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3554610','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3554610"><span id="translatedtitle">Histone H3K56 Acetylation, Rad52, and Non-DNA Repair Factors Control Double-Strand Break Repair Choice with the Sister <span class="hlt">Chromatid</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>Rothstein, Rodney; Aguilera, Andrés</p> <p>2013-01-01</p> <p>DNA double-strand breaks (DSBs) are harmful lesions that arise mainly during replication. The choice of the sister <span class="hlt">chromatid</span> as the preferential repair template is critical for genome integrity, but the mechanisms that guarantee this choice are unknown. Here we identify new genes with a specific role in assuring the sister <span class="hlt">chromatid</span> as the preferred repair template. Physical analyses of sister <span class="hlt">chromatid</span> recombination (SCR) in 28 selected mutants that increase Rad52 foci and inter-homolog recombination uncovered 8 new genes required for SCR. These include the SUMO/Ub-SUMO protease Wss1, the stress-response proteins Bud27 and Pdr10, the ADA histone acetyl-transferase complex proteins Ahc1 and Ada2, as well as the Hst3 and Hst4 histone deacetylase and the Rtt109 histone acetyl-transferase genes, whose target is histone H3 Lysine 56 (H3K56). Importantly, we use mutations in H3K56 residue to A, R, and Q to reveal that H3K56 acetylation/deacetylation is critical to promote SCR as the major repair mechanism for replication-born DSBs. The same phenotype is observed for a particular class of rad52 alleles, represented by rad52-C180A, with a DSB repair defect but a spontaneous hyper-recombination phenotype. We propose that specific Rad52 residues, as well as the histone H3 acetylation/deacetylation state of chromatin and other specific factors, play an important role in identifying the sister as the choice template for the repair of replication-born DSBs. Our work demonstrates the existence of specific functions to guarantee SCR as the main repair event for replication-born DSBs that can occur by two pathways, one Rad51-dependent and the other Pol32-dependent. A dysfunction can lead to genome instability as manifested by high levels of homolog recombination and DSB accumulation. PMID:23357952</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3608299','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3608299"><span id="translatedtitle">Aluminium phosphide-<span class="hlt">induced</span> genetic and oxidative damages in vitro: Attenuation by Laurus nobilis L. leaf extract</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Türkez, Hasan; Toğar, Başak</p> <p>2013-01-01</p> <p>Objective: The present investigation was undertaken to assess the protective effect of Laurus nobilis leaf extract (LNE) against aluminum phosphide (AIP)-<span class="hlt">induced</span> genotoxic and oxidative damages stress in cultured human blood cells in the presence of a metabolic activator (S9 mix). Materials and Methods: Sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) and chromosome aberration (CA) assays were used to assess AlP-<span class="hlt">induced</span> genotoxicity and to establish the protective effects of LNE. In addition, we determined total antioxidant capacity (TAC) and total oxidative status (TOS) levels in AlP and LNE treated cultures for biomonitoring the oxidative alterations. Results: There was significant increases (P < 0.05) in both SCE and CA frequencies of cultures treated with AlP as compared to controls. Our results also showed that AlP (58 mg/l) caused oxidative stress by altering TAC and TOS levels. However, co-application of LNE (25, 50, 100 and 200 mg/l) and AlP resulted in decreases of SCE, CA rates and TOS level and increases of TAC level as compared to the group treated with AlP alone. Conclusion: The preventive role of LNE in alleviating AlP-<span class="hlt">induced</span> DNA and oxidative damages was indicated for the first time in the present study. PMID:23543905</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7105076','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7105076"><span id="translatedtitle">Ultraviolet-<span class="hlt">induced</span> chromosomal instability in cultured fibroblasts of heterozygote carriers for xeroderma pigmentosum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bielfeld, V.; Weichenthal, M.; Roser, M.; Breitbart, E.; Berger, J.; Seemanova, E.; Ruediger, H.W. )</p> <p>1989-12-01</p> <p>Fibroblast cultures of seven patients with xeroderma pigmentosum (XP), 19 healthy sibs or parents of XP patients (XP-heterozygotes), and 24 healthy normal controls were studied for chromosome instability <span class="hlt">induced</span> by ultraviolet rays (UV). We used a UV source that contained predominantly UV-A and UV-B at an intensity of 500 J/m2 and evaluated the induction of micronuclei (MN) and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE). the XP homozygotes had a UV sensitivity that was clearly above that of all heterozygotes and normal controls. Heterozygotes had an increased rate of UV-<span class="hlt">induced</span> MN (4.76 {plus minus} 1.96 vs. 1.82 {plus minus} 2.05, p less than 0.0001) and increased UV induction of SCE (13.21 {plus minus} 3.49 vs. 9.01 {plus minus} 1.25, p less than 0.001), as compared to normal controls. These data support epidemiologic findings that suggest that XP heterozygotes are particularly cancer prone. In addition, the determination of the UV sensitivity in vitro as described may be used for genetic counseling of asymptomatic relatives of XP patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010mdpe.book...45G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010mdpe.book...45G"><span id="translatedtitle">Modeling of Membrane-Electrode-Assembly Degradation in Proton-<span class="hlt">Exchange</span>-Membrane Fuel Cells - Local H2 Starvation and Start-Stop <span class="hlt">Induced</span> Carbon-Support Corrosion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gu, Wenbin; Yu, Paul T.; Carter, Robert N.; Makharia, Rohit; Gasteiger, Hubert A.</p> <p></p> <p>Carbon-support corrosion causes electrode structure damage and thus electrode degradation. This chapter discusses fundamental models developed to predict cathode carbon-support corrosion <span class="hlt">induced</span> by local H2 starvation and start-stop in a proton-<span class="hlt">exchange</span>-membrane (PEM) fuel cell. Kinetic models based on the balance of current among the various electrode reactions are illustrative, yielding much insight on the origin of carbon corrosion and its implications for future materials developments. They are particularly useful in assessing carbon corrosion rates at a quasi-steady-state when an H2-rich region serves as a power source that drives an H2-free region as a load. Coupled kinetic and transport models are essential in predicting when local H2 starvation occurs and how it affects the carbon corrosion rate. They are specifically needed to estimate length scales at which H2 will be depleted and time scales that are valuable for developing mitigation strategies. To predict carbon-support loss distributions over an entire active area, incorporating the electrode pseudo-capacitance appears necessary for situations with shorter residence times such as start-stop events. As carbon-support corrosion is observed under normal transient operations, further model improvement shall be focused on finding the carbon corrosion kinetics associated with voltage cycling and incorporating mechanisms that can quantify voltage decay with carbon-support loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhyB..410...74P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhyB..410...74P"><span id="translatedtitle">The field-<span class="hlt">induced</span> laws of thermodynamic properties in the two-dimensional spin-1 ferromagnetic Heisenberg model with the <span class="hlt">exchange</span> and single-ion anisotropies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pu, Qiurong; Chen, Yuan</p> <p>2013-02-01</p> <p>Green's function method is applied to investigate the two-dimensional spin-1 ferromagnetic Heisenberg model with the <span class="hlt">exchange</span> and single-ion anisotropies. In the presence of the magnetic field, the effects of the anisotropies and field on the thermodynamic properties are obtained within the random phase approximation combining with Anderson-Callen approximation. The field-<span class="hlt">induced</span> laws are found for the thermodynamic properties. Field dependences of heights of the susceptibility maximum and specific heat maximum fit well to power laws. The linear increase at high fields is shown for positions of the susceptibility maximum and specific heat maximum. A power law at low fields occurs for the position of the susceptibility maximum. At the positions of the maxima, the magnetization and internal energy display the power-law increase and linear decrease with the field, respectively. The exponents of the power laws are dependent of the anisotropies, as well as the slopes of the linear laws. Our results do not support the 2/3 power law which was obtained by the Landau theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16409016','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16409016"><span id="translatedtitle">A full dimensional time-dependent wave packet study for the H4 four-center, collision <span class="hlt">induced</span> dissociation, and single <span class="hlt">exchange</span> reactions: reaction probabilities for J=0.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Yunpeng; Lee, Soo-Y; Zhang, Dong H</p> <p>2006-01-07</p> <p>A time-dependent initial state selected wave packet method has been developed to study the H2(v(1)=10-11,j1=0)+H2'(v2=0,j2=0)-->HH'+HH' four-center (4C) reaction, and two other competing reactions: the H2+H2'-->H+H+H2' collision <span class="hlt">induced</span> dissociation (CID) and the H2+H2'-->H+HH'+H' single <span class="hlt">exchange</span> (SE) reaction, in full six dimensions. Initial state-specific total reaction probabilities for these three competing reactions are presented for total angular momentum J=0 and the effects of reagent vibration on reactions are examined. It is found that (a) the CID process is the dominant process over the whole energy range considered in this study, but the 4C and SE processes also have non-negligible probabilities; (b) the SE process has a lower threshold energy than the 4C process, but the SE probability increases slower than the 4C probability as collision energy increases; (c) the vibrational excitation of H2(v1) is much more efficient than translational motion for promoting these processes, in particular to the CID process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21880903','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21880903"><span id="translatedtitle">Essential role for vav Guanine nucleotide <span class="hlt">exchange</span> factors in brain-derived neurotrophic factor-<span class="hlt">induced</span> dendritic spine growth and synapse plasticity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hale, Carly F; Dietz, Karen C; Varela, Juan A; Wood, Cody B; Zirlin, Benjamin C; Leverich, Leah S; Greene, Robert W; Cowan, Christopher W</p> <p>2011-08-31</p> <p>Brain-derived neurotrophic factor (BDNF) and its cognate receptor, TrkB, regulate a wide range of cellular processes, including dendritic spine formation and functional synapse plasticity. However, the signaling mechanisms that link BDNF-activated TrkB to F-actin remodeling enzymes and dendritic spine morphological plasticity remain poorly understood. We report here that BDNF/TrkB signaling in neurons activates the Vav family of Rac/RhoA guanine nucleotide <span class="hlt">exchange</span> factors through a novel TrkB-dependent mechanism. We find that Vav is required for BDNF-stimulated Rac-GTP production in cortical and hippocampal neurons. Vav is partially enriched at excitatory synapses in the postnatal hippocampus but does not appear to be required for normal dendritic spine density. Rather, we observe significant reductions in both BDNF-<span class="hlt">induced</span>, rapid, dendritic spine head growth and in CA3-CA1 theta burst-stimulated long-term potentiation in Vav-deficient mouse hippocampal slices, suggesting that Vav-dependent regulation of dendritic spine morphological plasticity facilitates normal functional synapse plasticity.</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> </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/18848466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18848466"><span id="translatedtitle">Probing peptide fragment ion structures by combining sustained off-resonance collision-<span class="hlt">induced</span> dissociation and gas-phase H/D <span class="hlt">exchange</span> (SORI-HDX) in Fourier transform ion-cyclotron resonance (FT-ICR) instruments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Somogyi, Arpád</p> <p>2008-12-01</p> <p>The usefulness of gas-phase H/D <span class="hlt">exchange</span> is demonstrated to probe heterogeneous fragment and parent ion populations. Singly and multiply protonated peptides/proteins were fragmented by using sustained off-resonance irradiation collision-<span class="hlt">induced</span> dissociation (SORI-CID). The fragments and the surviving precursor ions then all undergo H/D <span class="hlt">exchange</span> in the gas-phase with either D(2)O or CD(3)OD under the same experimental conditions. Usually, 10 to 60 s of reaction time is adequate to monitor characteristic differences in the H/D <span class="hlt">exchange</span> kinetic rates. These differences are then correlated to isomeric ion structures. The SORI-HDX method can be used to rapidly test fragment ion structures and provides useful insights into peptide fragmentation mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26852417','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26852417"><span id="translatedtitle">Nonadiabatic <span class="hlt">exchange</span> dynamics during adiabatic frequency sweeps.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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('https://www.ncbi.nlm.nih.gov/pubmed/19525383','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19525383"><span id="translatedtitle"><span class="hlt">Induced</span> overexpression of Na+/Ca2+ <span class="hlt">exchanger</span> transgene: altered myocyte contractility, [Ca2+]i transients, SR Ca2+ contents, and action potential duration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, JuFang; Chan, Tung O; Zhang, Xue-Qian; Gao, Erhe; Song, Jianliang; Koch, Walter J; Feldman, Arthur M; Cheung, Joseph Y</p> <p>2009-08-01</p> <p>We have produced mice in which expression of the rat cardiac Na(+)/Ca(2+) <span class="hlt">exchanger</span> (NCX1) transgene was switched on when doxycycline was removed from the feed at 5 wk. At 8 to 10 wk, NCX1 expression in <span class="hlt">induced</span> (Ind) mouse hearts was 2.5-fold higher but protein levels of sarco(endo)plasmic reticulum Ca(2+)-ATPase, alpha(1)- and alpha(2)-subunits of Na(+)-K(+)-ATPase, phospholamban, ryanodine receptor, calsequestrin, and unphosphorylated and phosphorylated phospholemman were unchanged compared with wild-type (WT) or noninduced (non-Ind) hearts. There was no cellular hypertrophy since WT, non-Ind, and Ind myocytes had similar whole cell membrane capacitance. In Ind myocytes, NCX1 current amplitude was approximately 42% higher, L-type Ca(2+) current amplitude was unchanged, and action potential duration was prolonged compared with WT or non-Ind myocytes. Contraction and intracellular Ca(2+) concentration ([Ca(2+)](i)) transient amplitudes in Ind myocytes were lower at 0.6, not different at 1.8, and higher at 5.0 mM extracellular Ca(2+) concentration ([Ca(2+)](o)) compared with WT or non-Ind myocytes. Despite similar Ca(2+) current amplitude and sarcoplasmic reticulum (SR) Ca(2+) uptake, SR Ca(2+) content at 5.0 mM [Ca(2+)](o) was significantly higher in Ind compared with non-Ind myocytes, indicating that NCX1 directly contributed to SR Ca(2+) loading. Echocardiography demonstrated that heart rate, left ventricular mass, ejection fraction, stroke volume, and cardiac output were similar among the three groups of animals. In vivo close-chest catheterization demonstrated similar contractility and relaxation among the three groups of mice, both at baseline and after stimulation with isoproterenol. We conclude that <span class="hlt">induced</span> expression of NCX1 transgene resulted in altered [Ca(2+)](i) homeostasis, myocyte contractility, and action potential morphology. In addition, heart failure did not occur 3 to 5 wk after NCX1 transgene was <span class="hlt">induced</span> to be expressed at levels found in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70178327','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70178327"><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, Donald O.; Healy, Richard 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</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> <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('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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2697716','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2697716"><span id="translatedtitle">The role of the Na+/Ca2+ <span class="hlt">exchanger</span>, INa and ICaL in the genesis of dofetilide-<span class="hlt">induced</span> torsades de pointes in isolated, AV-blocked rabbit hearts</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Farkas, Attila S; Makra, Péter; Csík, Norbert; Orosz, Szabolcs; Shattock, Michael J; Fülöp, Ferenc; Forster, Tamás; Csanády, Miklós; Papp, Julius Gy; Varró, András; Farkas, András</p> <p>2009-01-01</p> <p>Background and purpose: The Na+/Ca2+ <span class="hlt">exchanger</span> (NCX) may contribute to triggered activity and transmural dispersion of repolarization, which are substrates of torsades de pointes (TdP) type arrhythmias. This study examined the effects of selective inhibition of the NCX by SEA0400 on the occurrence of dofetilide-<span class="hlt">induced</span> TdP. Experimental approach: Effects of SEA0400 (1 µmol·L−1) on dofetilide-<span class="hlt">induced</span> TdP was studied in isolated, Langendorff-perfused, atrioventricular (AV)-blocked rabbit hearts. To verify the relevance of the model, lidocaine (30 µmol·L−1) and verapamil (750 nmol·L−1) were also tested against dofetilide-<span class="hlt">induced</span> TdP. Key results: Acute AV block caused a chaotic idioventricular rhythm and strikingly increased beat-to-beat variability of the RR and QT intervals. SEA0400 exaggerated the dofetilide-<span class="hlt">induced</span> increase in the heart rate-corrected QT interval (QTc) and did not reduce the incidence of dofetilide-<span class="hlt">induced</span> TdP [100% in the SEA0400 + dofetilide group vs. 75% in the dofetilide (100 nmol·L−1) control]. In the second set of experiments, verapamil further increased the dofetilide-<span class="hlt">induced</span> QTc prolongation and neither verapamil nor lidocaine reduced the dofetilide-<span class="hlt">induced</span> increase in the beat-to-beat variability of the QT interval. However, lidocaine decreased and verapamil prevented the development of dofetilide-<span class="hlt">induced</span> TdP as compared with the dofetilide control (TdP incidence: 13%, 0% and 88% respectively). Conclusions and implications: Na+/Ca2+ <span class="hlt">exchanger</span> does not contribute to dofetilide-<span class="hlt">induced</span> TdP, whereas Na+ and Ca2+ channel activity is involved in TdP genesis in isolated, AV-blocked rabbit hearts. Neither QTc prolongation nor an increase in the beat-to-beat variability of the QT interval is a sufficient prerequisite of TdP genesis in rabbit hearts. PMID:19222480</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23959673','PUBMED'); return false;" href="https://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/servlets/purl/1176550','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176550"><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>Brackenbury, Phillip J.</p> <p>1986-04-01</p> <p>A heat <span class="hlt">exchanger</span> comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22416738','SCIGOV-STC'); return false;" href="https://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=4872126','PMC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/16238299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16238299"><span id="translatedtitle">Unexpected formation of 1-diethylaminobutadiene in photosensitized oxidation of triethylamine <span class="hlt">induced</span> by 2,3-dihydro-oxoisoaporphine dyes. A 1H NMR and isotopic <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 la Fuente, Julio R; Jullian, Carolina; Saitz, Claudio; Neira, Verónica; Poblete, Oscar; Sobarzo-Sánchez, Eduardo</p> <p>2005-10-28</p> <p>[reaction: see text] Photoreduction of oxoisoaporphine dyes occurs via a stepwise mechanism of electron-proton-electron transfer that leads to the N-hydrogen oxoisoaporphine anion. When triethylamine, TEA, was used as the electron donor in anaerobic conditions, 1-diethylaminobutadiene, DEAB, was one of the oxidation products of TEA, among diethylamine and acetaldehyde. DEAB was identified by (1)H NMR and GC-MS experiments by comparison with the authentic 1-diethylaminobutadiene. This is the first report of a butadienyl derivative formed in the dye-sensitized photooxidation of TEA. In addition, isotopic <span class="hlt">exchange</span> experiments with TEA-d(15) and D(2)O show that the hydrogens at carbon-2 and carbon-4 of the butadienyl moiety are <span class="hlt">exchangeable</span>. The observed isotopic <span class="hlt">exchange</span> pattern could be explained by the head-to-tail coupling of an N,N-diethylvinylamine intermediate that <span class="hlt">exchanges</span> hydrogens at the C-beta via the enammonium ion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.H33B..12S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.H33B..12S"><span id="translatedtitle">Propagating of uncertainties due to human-<span class="hlt">induced</span> surface-heterogeneities in regional estimation of energy and mass <span class="hlt">exchange</span> from flux aggregation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siqueira, M. B.</p> <p>2013-05-01</p> <p>Agriculture and forestry practices have added a multitude of vegetation heterogeneity scales to the landscape. The effects of the human <span class="hlt">induced</span> heterogeneity, such as multi-crop agriculture and selective logging, on regional estimates of gas <span class="hlt">exchange</span> from remote sensing platforms can now be added to the list of major problems that must be confronted by the ecohydrology communities. The last decade provided perhaps the most rapid advances given developments in satellite remote sensing products and computational methods. Recent studies on sub-pixel heterogeneity effects on pixel-averaged fluxes using a two-source (soil + vegetation) energy balance model over semi-arid landscapes have concluded that sub-pixel variability could lead to significantly biased results when compared to true turbulent energy fluxes. Moreover, these studies have shown that errors in outputs from flux models driven by remotely sensed surface properties would be dependent on the distribution and the magnitude of the sub-pixel spatial variability. In addition, it has been demonstrated that the discrepancy is not only associated with the spatial variability level but also a function of the wind speed (i.e. the turbulent state of the atmosphere), suggesting that a formal analysis of turbulence on scalar transport is the logical step to increase confidence in subpixel flux estimates under these circumstances. Computational-fluid-mechanic studies point towards the importance of sub-pixel spatial heterogeneity on regional flux estimates, suggesting that they are sensitive to the scale of the land surface heterogeneity. These studies primarily considered the effects of small-scale (sub-grid) heterogeneity on pixel-scale energy budgets. However, the emergent theme remains the same - large uncertainties are associated with fluxes derived from spatially averaged surface properties. To advance in this topic, the heterogeneity should be confronted with two dynamic-length-scale, namely, the convective scale</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.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('https://www.ncbi.nlm.nih.gov/pubmed/18253721','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18253721"><span id="translatedtitle">Cell protection <span class="hlt">induced</span> by beta-sitosterol: inhibition of genotoxic damage, stimulation of lymphocyte production, and determination of its antioxidant capacity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Paniagua-Pérez, R; Madrigal-Bujaidar, E; Reyes-Cadena, S; Alvarez-González, I; Sánchez-Chapul, L; Pérez-Gallaga, J; Hernández, N; Flores-Mondragón, G; Velasco, O</p> <p>2008-09-01</p> <p>Beta-sitosterol (BS) is a compound that has shown various activities potentially useful for human health. In the present study, we determined its antigenotoxic capacity and lymphocyte induction potential in mouse as well as its capacity to trap free radicals in vitro. BS, in doses from 200 to 1,000 mg/kg, was able to significantly reduce the frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> <span class="hlt">induced</span> by 10 mg/kg of doxorubicin (DX) in bone marrow cells. The same range of BS doses also gave rise to a strong reduction in the rate of micronucleated, polychromatic erythrocytes <span class="hlt">induced</span> by DX. In addition, we determined an increase in the production of lymphocytes in mice administered with BS. By means of the DPPH assay, the compound was shown to trap free radicals in a concentration dependent manner as high as 78.12% using 250 mug/ml. Our research established three relevant biological activities of BS which show its potential as a chemopreventive agent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6408254','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6408254"><span id="translatedtitle">Effects of cellular non-protein sulfhydryl depletion in radiation <span class="hlt">induced</span> oncogenic transformation and genotoxicity in mouse C/sub 3/H 10T1/2 cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hei, T.K.; Geard, C.R.; Hall, E.J.</p> <p>1984-08-01</p> <p>A study was made of the effects of cellular non-protein sulfhydryl (NPSH) depletion on cytotoxicity, cell cycle kinetics, oncogenic transformation and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) in C/sub 3/H 10T1/2 cells. Using DL-Buthionine S-R-Sulfoximine (BSO) to deplete thiols, it was found spectrophotometrically that less than 5% of control NPSH level remained in the cells after 24-hour treatment under aerated conditions. Such NPSH depleted cells, when subject to a 3 Gy ..gamma..-ray treatment, were found to have no radiosensitizing response either in terms of cell survival or oncogenic transformation. In addition, decreased levels of NPSH had no effect on spontaneous or radiation-<span class="hlt">induced</span> SCE nor were cell cycle kinetics additionally altered. Therefore, the inability of NPSH depletion to alter ..gamma..-ray <span class="hlt">induced</span> cellular transformation was unrelated to any possible effect of BSO on the cell cycle. These results suggest that such depletion may result in little or no additional oncogenic or genotoxic effects on aerated normal tissues.</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('https://www.ncbi.nlm.nih.gov/pubmed/21875949','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21875949"><span id="translatedtitle">Ginseng (Panax quinquefolius) attenuates leptin-<span class="hlt">induced</span> cardiac hypertrophy through inhibition of p115Rho guanine nucleotide <span class="hlt">exchange</span> factor-RhoA/Rho-associated, coiled-coil containing protein kinase-dependent mitogen-activated protein kinase pathway activation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moey, Melissa; Rajapurohitam, Venkatesh; Zeidan, Asad; Karmazyn, Morris</p> <p>2011-12-01</p> <p>Leptin is a 16-kDa peptide primarily derived from white adipocytes and is typically elevated in plasma of obese individuals. Although leptin plays a critical role in appetite regulation, leptin receptors have been identified in numerous tissues including the heart and have been shown to directly mediate cardiac hypertrophy through RhoA/ROCK (Ras homolog gene family, member A/Rho-associated, coiled-coil containing protein kinase)-dependent p38 mitogen-activated protein kinase (MAPK) activation; however, the basis for RhoA stimulation is unknown. Rho guanine nucleotide <span class="hlt">exchange</span> factors (GEFs) catalyze the <span class="hlt">exchange</span> of GDP for GTP resulting in Rho activation and may be the potential upstream factors mediating leptin-<span class="hlt">induced</span> RhoA activation and therefore a potential target for inhibition. We investigated the effects of North American ginseng (Panax quinquefolius), reported to reduce cardiac hypertrophy, on RhoA/ROCK and MAPK activation in ventricular cardiomyocytes exposed to leptin (50 ng/ml) and the possible role of p115RhoGEF and p63RhoGEF in these responses. Leptin produced a robust hypertrophic response that was associated with RhoA/ROCK activation resulting in a significant increase in cofilin-2 phosphorylation and actin polymerization, the latter evidenced by a reduction in the G/F actin ratio. These effects were prevented by ginseng (10 μg/ml). The stimulation of RhoA/ROCK by leptin was associated with significantly increased p115RhoGEF gene and protein expression and <span class="hlt">exchange</span> activity, all of which were completely prevented by ginseng. The ability of ginseng to prevent leptin-<span class="hlt">induced</span> activation of RhoA/ROCK was further associated with diminished p38 MAPK activation and nuclear translocation. These results demonstrate a potent inhibitory effect of ginseng against leptin-<span class="hlt">induced</span> cardiac hypertrophy, an effect associated with prevention of p115RhoGEF-RhoA/ROCK-dependent p38 MAPK activation.</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.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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JChPh.128b4103S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JChPh.128b4103S"><span id="translatedtitle"><span class="hlt">Exchange</span> frequency in replica <span class="hlt">exchange</span> molecular dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sindhikara, Daniel; Meng, Yilin; Roitberg, Adrian E.</p> <p>2008-01-01</p> <p>The effect of the <span class="hlt">exchange</span>-attempt frequency on sampling efficiency is studied in replica <span class="hlt">exchange</span> molecular dynamics (REMD). We show that sampling efficiency increases with increasing <span class="hlt">exchange</span>-attempt frequency. This conclusion is contrary to a commonly expressed view in REMD. Five peptides (1-21 residues long) are studied with a spectrum of <span class="hlt">exchange</span>-attempt rates. Convergence rates are gauged by comparing ensemble properties between fixed length test REMD simulations and longer reference simulations. To show the fundamental correlation between <span class="hlt">exchange</span> frequency and convergence time, a simple model is designed and studied, displaying the same basic behavior of much more complex systems.</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('https://www.osti.gov/scitech/biblio/6515249','SCIGOV-STC'); return false;" href="https://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://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('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/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('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('https://www.ncbi.nlm.nih.gov/pubmed/19482912','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19482912"><span id="translatedtitle">Protective role of vitamins A, C, and E against the genotoxic damage <span class="hlt">induced</span> by aflatoxin B1 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>Alpsoy, L; Agar, G; Ikbal, M</p> <p>2009-04-01</p> <p>In this study, we aimed to evaluate the effect of vitamins A, C, and E against aflatoxin B1 (AFB1) on blood cultures in relation to induction of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE). The results indicated genotoxic and mutagenic damage in cultured human lymphocytes exposed to AFB1. The results showed that 5 microM concentration of AFB1 increased SCE. When vitamins A, C, and E were added to AFB1, the frequency of SCE decreased. These results suggest that vitamins A, C, and E could effectively inhibit AFB1-<span class="hlt">induced</span> SCE, which may partially responsible for its mutagenic effect of AFB1. Besides, the protective effect of vitamins A, C, and E against AFB1 was increased in a dose-dependent manner (i.e., as the doses increased, their protective effects also increased). There was a significant decrease in the SCE frequency in AFB1-treated group compared with the groups receiving AFB1 and also vitamins A, C, and E. The most effective concentration was 100 microM vitamin C, and the lowest effective concentration was 0.5 microM vitamin A. Vitamin C has the most effective concentration of 100 microM, and vitamin A has the lowest effective concentration of 0.5 microM. The order of the decreasing effect of the SCE frequency of vitamins was as follows: vitamin C > vitamin E > vitamin A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5844458','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5844458"><span id="translatedtitle">Comparative cytogenetic analysis of bone marrow damage <span class="hlt">induced</span> in male B6C3F1 mice by multiple exposures to gaseous 1,3-butadiene</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tice, R.R.; Boucher, R.; Luke, C.A.; Shelby, M.D.</p> <p>1987-01-01</p> <p>Groups of male B6C3F1 mice were exposed to ambient air or to gaseous 1,3-butadiene (BD) at 6.25, 62.5, and 625 ppm for 10 exposure days. Exposure to BD <span class="hlt">induced</span> in bone marrow: 1) a significant increase in the frequency of chromosomal aberrations (CA); 2) a significant elevation in the frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE); 3) a significant lengthening of the average generation time (AGT); 4) a significant depression in the mitotic index (MI): and, as measured in the peripheral blood, 5) a significant increase in the proportion of circulating polychromatic erythrocytes (% PCE), and 6) a significant increase in the level of micronucleated PCE (MN-PCE) and micronucleated normochromatic erythrocytes (MN-NCE). The most sensitive indicator of genotoxic damage was the frequency of SCE, followed by MN-PCE levels, and then by CA and MN-NCE frequencies. The most sensitive measure of cytotoxic damage was AGT followed by % PCE and then my MI. The extent of concordance ranged from a very good correlation between the induction of MN-PCE and the induction of SCE to the lack of a significant correlation between the depression in the MI and any other endpoint.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22342611','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22342611"><span id="translatedtitle">The modifying effect of selenium and vitamins A, C, and E on the genotoxicity <span class="hlt">induced</span> by sunset yellow in male mice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sayed, Hanaa M; Fouad, Dalia; Ataya, Farid S; Hassan, Nagwa H A; Fahmy, Maha A</p> <p>2012-05-15</p> <p>The use of food additives in various products is growing up. It has attracted the attention towards the possible correlation between the mutagenic potential of food additives and various human diseases. This work evaluated the protective role of selenium and vitamins A, C and E (selenium ACE)(1) against the genotoxic effects <span class="hlt">induced</span> by a synthetic food additive, sunset yellow, in mice. Six groups were studied including two control groups (negative and positive control), two groups are given single dose of sunset yellow (either 0.325, 0.65 or 1.3mg/kg body weight(2) alone or with selenium ACE) and two groups are given sunset yellow daily for 1, 2 or 3 weeks (0.325mg/kg b.wt./day alone or with selenium ACE), respectively. The study examined the induction of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE's)(3) in bone-marrow cells, chromosomal aberration in somatic (bone-marrow) and germ cells (spermatocytes) after single and repeated oral treatment, and the induction of morphological sperm abnormalities. The results showed that sunset yellow had genotoxic effects as indicated by increased frequency of SCE's, by chromosomal aberrations in both somatic and germ cells, and by increased morphological sperm abnormalities and DNA fragmentation. The results also indicated that the oral administration of selenium ACE significantly reduced the genotoxic effects of sunset yellow, a result that may support the use of antioxidants as chemopreventive agents in many applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25025061','PUBMED'); return false;" href="https://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.</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.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/20617204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20617204"><span id="translatedtitle">Cohesin Is limiting for the suppression of DNA damage-<span class="hlt">induced</span> recombination 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>Covo, Shay; Westmoreland, James W; Gordenin, Dmitry A; Resnick, Michael A</p> <p>2010-07-01</p> <p>Double-strand break (DSB) repair through homologous recombination (HR) is an evolutionarily conserved process that is generally error-free. The risk to genome stability posed by nonallelic recombination or loss-of-heterozygosity could be reduced by confining HR to sister <span class="hlt">chromatids</span>, thereby preventing recombination between homologous chromosomes. Here we show that the sister <span class="hlt">chromatid</span> cohesion complex (cohesin) is a limiting factor in the control of DSB repair and genome stability and that it suppresses DNA damage-<span class="hlt">induced</span> interactions between homologues. We developed a gene dosage system in tetraploid yeast to address limitations on various essential components in DSB repair and HR. Unlike RAD50 and RAD51, which play a direct role in HR, a 4-fold reduction in the number of essential MCD1 sister <span class="hlt">chromatid</span> cohesion subunit genes affected survival of gamma-irradiated G(2)/M cells. The decreased survival reflected a reduction in DSB repair. Importantly, HR between homologous chromosomes was strongly increased by ionizing radiation in G(2)/M cells with a single copy of MCD1 or SMC3 even at radiation doses where survival was high and DSB repair was efficient. The increased recombination also extended to nonlethal doses of UV, which did not <span class="hlt">induce</span> DSBs. The DNA damage-<span class="hlt">induced</span> recombinants in G(2)/M cells included crossovers. Thus, the cohesin complex has a dual role in protecting chromosome integrity: it promotes DSB repair and recombination between sister <span class="hlt">chromatids</span>, and it suppresses damage-<span class="hlt">induced</span> recombination between homologues. The effects of limited amounts of Mcd1and Smc3 indicate that small changes in cohesin levels may increase the risk of genome instability, which may lead to genetic diseases and cancer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..MARZ35001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..MARZ35001B"><span id="translatedtitle">Photophysical Properties of Colloidal Mn(II)-Doped CdSe Nanoparticles: <span class="hlt">Exchange</span> Fields, Exciton Storage, and Light-<span class="hlt">Induced</span> Spontaneous Magnetization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beaulac, Remi</p> <p>2010-03-01</p> <p>An attractive approach to controlling spin effects in semiconductor nanostructures for applications in electronics is to use light to generate, manipulate, or read out spins. The main focus of this presentation will be on the recent demonstration of spontaneous photoinduced polarization of Mn(II) spins in doped colloidal CdSe quantum dots, an effect due to the formation of excitonic magnetic polarons. Photoexcitation generates large dopant-carrier <span class="hlt">exchange</span> fields, enhanced by strong spatial confinement, that lead to giant Zeeman splittings of the semiconductor band structure in the absence of applied magnetic fields. These internal <span class="hlt">exchange</span> fields allow spontaneous magnetic saturation of the Mn(II) spins to be achieved at zero external magnetic field up to ca. 50 K, and photomagnetic effects are observed all the way up to room temperature. The factors that allow this fascinating effect to be observed in colloidal Mn(II)-doped CdSe nanoparticles will be discussed. Relevant Publications: 1) Beaulac, Schneider, Archer, Bacher, and Gamelin. Science, 325, 973 (2009) 2) Beaulac, Archer, Ochsenbein, and Gamelin, Adv. Funct. Mat., 18, 3873 (2008)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11564864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11564864"><span id="translatedtitle">Involvement of alpha-PAK-interacting <span class="hlt">exchange</span> factor in the PAK1-c-Jun NH(2)-terminal kinase 1 activation and apoptosis <span class="hlt">induced</span> by benzo[a]pyrene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoshii, S; Tanaka, M; Otsuki, Y; Fujiyama, T; Kataoka, H; Arai, H; Hanai, H; Sugimura, H</p> <p>2001-10-01</p> <p>Benzo[a]pyrene [B(a)P], a potent procarcinogen found in combustion products such as diesel exhaust and cigarette smoke, has been recently shown to activate the c-Jun NH(2)-terminal kinase 1 (JNK1) and <span class="hlt">induce</span> caspase-3-mediated apoptosis in Hepa1c1c7 cells. However, the molecules of the signaling pathway that control the mitogen-activated protein kinase cascades <span class="hlt">induced</span> by B(a)P and the interaction between those and apoptosis by B(a)P have not been well defined. We report here that B(a)P promoted Cdc42/Rac1, p21-activated kinase 1 (PAK1), and JNK1 activities in 293T and HeLa cells. Moreover, alpha-PAK-interacting <span class="hlt">exchange</span> factor (alpha PIX) mRNA and its protein expression were upregulated by B(a)P. While overexpression of an active mutant of alpha PIX (DeltaCH) facilitated B(a)P-<span class="hlt">induced</span> activation of Cdc42/Rac1, PAK1, and JNK1, overexpression of mutated alphaPIX (L383R, L384S), which lacks guanine nucleotide <span class="hlt">exchange</span> factor activity, SH3 domain-deleted alphaPIX (Delta SH3), which lacks the ability to bind PAK, kinase-negative PAK1 (K299R), and kinase-negative SEK1 (K220A, K224L) inhibited B(a)P-triggered JNK1 activation. Interestingly, overexpression of alphaPIX (Delta CH) and a catalytically active mutant PAK1 (T423E) accelerated B(a)P-<span class="hlt">induced</span> apoptosis in HeLa cells, whereas alphaPIX (Delta SH3), PAK1 (K299R), and SEK 1 (K220A, K224L) inhibited B(a)P-initiated apoptosis. Finally, a preferential caspase inhibitor, Z-Asp-CH2-DCB, strongly blocked the alphaPIX (Delta CH)-enhanced apoptosis in cells treated with B(a)P but did not block PAK1/JNK1 activation. Taken together, these results indicate that alphaPIX plays a crucial role in B(a)P-<span class="hlt">induced</span> apoptosis through activation of the JNK1 pathway kinases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.139n4203C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.139n4203C"><span id="translatedtitle">Nuclear magnetic relaxation <span class="hlt">induced</span> by <span class="hlt">exchange</span>-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Zhiwei; Halle, Bertil</p> <p>2013-10-01</p> <p>In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via <span class="hlt">exchange</span>-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical <span class="hlt">exchange</span> processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25578862','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25578862"><span id="translatedtitle">RhoA Kinase (Rock) and p90 Ribosomal S6 Kinase (p90Rsk) phosphorylation of the sodium hydrogen <span class="hlt">exchanger</span> (NHE1) is required for lysophosphatidic acid-<span class="hlt">induced</span> transport, cytoskeletal organization 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>Wallert, Mark A; Hammes, Daniel; Nguyen, Tony; Kiefer, Lea; Berthelsen, Nick; Kern, Andrew; Anderson-Tiege, Kristina; Shabb, John B; Muhonen, Wallace W; Grove, Bryon D; Provost, Joseph J</p> <p>2015-03-01</p> <p>The sodium hydrogen <span class="hlt">exchanger</span> isoform one (NHE1) plays a critical role coordinating asymmetric events at the leading edge of migrating cells and is regulated by a number of phosphorylation events influencing both the ion transport and cytoskeletal anchoring required for directed migration. Lysophosphatidic acid (LPA) activation of RhoA kinase (Rock) and the Ras-ERK growth factor pathway <span class="hlt">induces</span> cytoskeletal reorganization, activates NHE1 and <span class="hlt">induces</span> an increase in cell motility. We report that both Rock I and II stoichiometrically phosphorylate NHE1 at threonine 653 in vitro using mass spectrometry and reconstituted kinase assays. In fibroblasts expressing NHE1 alanine mutants for either Rock (T653A) or ribosomal S6 kinase (Rsk; S703A) we show that each site is partially responsible for the LPA-<span class="hlt">induced</span> increase in transport activity while NHE1 phosphorylation by either Rock or Rsk at their respective site is sufficient for LPA stimulated stress fiber formation and migration. Furthermore, mutation of either T653 or S703 leads to a higher basal pH level and a significantly higher proliferation rate. Our results identify the direct phosphorylation of NHE1 by Rock and suggest that both RhoA and Ras pathways mediate NHE1-dependent ion transport and migration in fibroblasts.</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> </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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3398457','PMC'); return false;" href="https://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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183305','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183305"><span id="translatedtitle">Absence of SUN-domain protein Slp1 blocks karyogamy and switches meiotic recombination and synapsis from homologs to 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>Vasnier, Christelle; de Muyt, Arnaud; Zhang, Liangran; Tessé, Sophie; Kleckner, Nancy E.; Zickler, Denise; Espagne, Eric</p> <p>2014-01-01</p> <p>Karyogamy, the process of nuclear fusion is required for two haploid gamete nuclei to form a zygote. Also, in haplobiontic organisms, karyogamy is required to produce the diploid nucleus/cell that then enters meiosis. We identify sun like protein 1 (Slp1), member of the mid–Sad1p, UNC-84–domain ubiquitous family, as essential for karyogamy in the filamentous fungus Sordaria macrospora, thus uncovering a new function for this protein family. Slp1 is required at the last step, nuclear fusion, not for earlier events including nuclear movements, recognition, and juxtaposition. Correspondingly, like other family members, Slp1 localizes to the endoplasmic reticulum and also to its extensions comprising the nuclear envelope. Remarkably, despite the absence of nuclear fusion in the slp1 null mutant, meiosis proceeds efficiently in the two haploid “twin” nuclei, by the same program and timing as in diploid nuclei with a single dramatic exception: the normal prophase program of recombination and synapsis between homologous chromosomes, including loading of recombination and synaptonemal complex proteins, occurs instead between sister <span class="hlt">chromatids</span>. Moreover, the numbers of recombination-initiating double-strand breaks (DSBs) and ensuing recombinational interactions, including foci of the essential crossover factor Homo sapiens enhancer of invasion 10 (Hei10), occur at half the diploid level in each haploid nucleus, implying per-chromosome specification of DSB formation. Further, the distribution of Hei10 foci shows interference like in diploid meiosis. Centromere and spindle dynamics, however, still occur in the diploid mode during the two meiotic divisions. These observations imply that the prophase program senses absence of karyogamy and/or absence of a homolog partner and adjusts the interchromosomal interaction program accordingly. PMID:25210014</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25210014','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25210014"><span id="translatedtitle">Absence of SUN-domain protein Slp1 blocks karyogamy and switches meiotic recombination and synapsis from homologs to sister <span class="hlt">chromatids</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vasnier, Christelle; de Muyt, Arnaud; Zhang, Liangran; Tessé, Sophie; Kleckner, Nancy E; Zickler, Denise; Espagne, Eric</p> <p>2014-09-23</p> <p>Karyogamy, the process of nuclear fusion is required for two haploid gamete nuclei to form a zygote. Also, in haplobiontic organisms, karyogamy is required to produce the diploid nucleus/cell that then enters meiosis. We identify sun like protein 1 (Slp1), member of the mid-Sad1p, UNC-84-domain ubiquitous family, as essential for karyogamy in the filamentous fungus Sordaria macrospora, thus uncovering a new function for this protein family. Slp1 is required at the last step, nuclear fusion, not for earlier events including nuclear movements, recognition, and juxtaposition. Correspondingly, like other family members, Slp1 localizes to the endoplasmic reticulum and also to its extensions comprising the nuclear envelope. Remarkably, despite the absence of nuclear fusion in the slp1 null mutant, meiosis proceeds efficiently in the two haploid "twin" nuclei, by the same program and timing as in diploid nuclei with a single dramatic exception: the normal prophase program of recombination and synapsis between homologous chromosomes, including loading of recombination and synaptonemal complex proteins, occurs instead between sister <span class="hlt">chromatids</span>. Moreover, the numbers of recombination-initiating double-strand breaks (DSBs) and ensuing recombinational interactions, including foci of the essential crossover factor Homo sapiens enhancer of invasion 10 (Hei10), occur at half the diploid level in each haploid nucleus, implying per-chromosome specification of DSB formation. Further, the distribution of Hei10 foci shows interference like in diploid meiosis. Centromere and spindle dynamics, however, still occur in the diploid mode during the two meiotic divisions. These observations imply that the prophase program senses absence of karyogamy and/or absence of a homolog partner and adjusts the interchromosomal interaction program accordingly.</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.ncbi.nlm.nih.gov/pubmed/19032443','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19032443"><span id="translatedtitle">Drought-<span class="hlt">induced</span> hydraulic limitations constrain leaf gas <span class="hlt">exchange</span> recovery after precipitation pulses in the C3 woody legume, Prosopis velutina.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Resco, Víctor; Ewers, Brent E; Sun, Wei; Huxman, Travis E; Weltzin, Jake F; Williams, David G</p> <p>2009-01-01</p> <p>The hypothesis that drought intensity constrains the recovery of photosynthesis from drought was tested in the C(3) woody legume Prosopis velutina, and the mechanisms underlying this constraint examined. Hydraulic status and gas <span class="hlt">exchange</span> were measured the day before a 39 mm precipitation pulse, and up to 7 d afterwards. The experiment was conducted under rainout shelters, established on contrasting soil textures and with different vegetation cover at the Santa Rita Experimental Range in southeastern Arizona, USA. Rates of photosynthesis and stomatal conductance after re-watering, as well as the number of days necessary for photosynthesis to recover after re-watering, were negatively correlated with predawn water potential, a measure of drought intensity (R(2) = 0.83, 0.64 and 0.92, respectively). Photosynthetic recovery was incomplete when the vascular capacity for water transport had been severely impaired (percentage loss of hydraulic conductance > 80%) during the drought, which largely increased stomatal limitations. However, changes in biochemical capacity or in mesophyll conductance did not explain the observed pattern of photosynthesis recovery. Although the control that hydraulic limitations impose on photosynthesis recovery had been previously inferred, the first empirical test of this concept is reported here.</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://adsabs.harvard.edu/abs/2012PhDT........20H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT........20H"><span id="translatedtitle">The Electrically Controlled <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>Harper, Jacob</p> <p></p> <p>/CoO bilayer is deposited on the surface of BaTiO 3 substrate which allows for tunable stress in the adjacent Co thin film. This stress <span class="hlt">induces</span> strain in the Co film thus alters its magnetic anisotropy. The change of the magnetization orientation at the Co/CoO interface tunes its <span class="hlt">exchange</span> bias and coercivity and provides a route to study the interface magnetism of the <span class="hlt">exchange</span> bias heterostructure from a new perspective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=369184','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=369184"><span id="translatedtitle">Meiotic <span class="hlt">exchange</span> within and between chromosomes requires a common Rec function 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>Wagstaff, J E; Klapholz, S; Waddell, C S; Jensen, L; Esposito, R E</p> <p>1985-01-01</p> <p>We used haploid yeast cells that express both the MATa and MAT alpha mating-type alleles and contain the spo13-1 mutation to characterize meiotic recombination within single, unpaired chromosomes in Rec+ and Rec- Saccharomyces cerevisiae. In Rec+ haploids, as in diploids, intrachromosomal recombination in the ribosomal DNA was detected in 2 to 6% of meiotic divisions, and most events were unequal reciprocal sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE). By contrast, intrachromosomal recombination between duplicated copies of the his4 locus occurred in approximately 30% of haploid meiotic divisions, a frequency much higher than that reported in diploids; only about one-half of the events were unequal reciprocal SCE. The spo11-1 mutation, which virtually eliminates meiotic <span class="hlt">exchange</span> between homologs in diploid meiosis, reduced the frequency of intrachromosomal recombination in both the ribosomal DNA and the his4 duplication during meiosis by 10- to greater than 50-fold. This Rec- mutation affected all forms of recombination within chromosomes: unequal reciprocal SCE, reciprocal intrachromatid <span class="hlt">exchange</span>, and gene conversion. Intrachromosomal recombination in spo11-1 haploids was restored by transformation with a plasmid containing the wild-type SPO11 gene. Mitotic intrachromosomal recombination frequencies were unaffected by spo11-1. This is the first demonstration of a gene product required for recombination between homologs as well as recombination within chromosomes during meiosis. Images PMID:3915779</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27192441','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27192441"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Zixing; Waadt, Rainer; Schroeder, Julian I</p> <p>2016-05-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28167534','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28167534"><span id="translatedtitle">Detection of Lipid <span class="hlt">Induced</span> Structural Changes of the Marburg Virus Matrix Protein VP40 Using Hydrogen/Deuterium <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>Wijesinghe, Kaveesha J; Urata, Sarah; Bhattarai, Nisha; Kooijman, Edgar E; Gerstman, Bernard S; Chapagain, Prem P; Li, Sheng; Stahelin, Robert V</p> <p>2017-02-06</p> <p>Marburg virus (MARV) is a lipid-enveloped virus from the Filoviridae family containing a negative sense RNA genome. One of the seven MARV genes encodes the matrix protein VP40, which forms a matrix layer beneath the plasma membrane inner leaflet to facilitate budding from the host cell. MARV VP40 (mVP40) has been shown to be a dimeric peripheral protein with a broad and flat basic surface that can associate with anionic phospholipids such as phosphatidylserine. While a number of mVP40 cationic residues have been shown to facilitate binding to membranes containing anionic lipids, much less is known on how mVP40 assembles to form the matrix layer following membrane binding. Here we have used hydrogen-deuterium <span class="hlt">exchange</span> (H/DX) mass spectrometry to determine the solvent accessibility of mVP40 residues in the absence and presence of phosphatidylserine and phosphatidylinositol-4,5-bisphosphate. H/DX analysis demonstrates two basic loops in the mVP40 C-terminal domain make important contributions to anionic membrane binding and also revealed a potential oligomerization interface in the C-terminal domain as well as a conserved oligomerization interface in the mVP40 N-terminal domain. Lipid binding assays confirm the role of the two basic patches elucidated with HD/X measurements while molecular dynamics simulations and membrane insertion measurements complement these studies to demonstrate mVP40 doesn't appreciably insert into the hydrocarbon region of anionic membranes in contrast to the matrix protein from Ebola virus. Taken together, we propose a model by which association of the mVP40 dimer with the anionic plasma membrane facilitates assembly of mVP40 oligomers.</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('https://www.ncbi.nlm.nih.gov/pubmed/8427015','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8427015"><span id="translatedtitle">SCE frequencies <span class="hlt">induced</span> by ethanol, tequila and brandy in mouse bone marrow cells in vivo.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Piña Calva, A; Madrigal-Bujaidar, E</p> <p>1993-01-01</p> <p>The genotoxicity of ethanol, tequila and brandy was evaluated by scoring the frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE) and determining the values of the average generation time (AGT). We studied four dosages of each substance i.p. inoculated into mice. The cytogenetic analysis was performed in bone marrow cells. The results showed that all three substances were weak genotoxicants. Tequila showed the strongest response followed by brandy and ethanol. None of them modified the cell proliferation kinetics as demonstrated by the AGT results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21843205','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21843205"><span id="translatedtitle">Protective effects of a magnesium magnetic isotope (Mg25)-<span class="hlt">exchanging</span> nanoparticle (25MgPMC16 ) on mitochondrial functional disorders in esmolol-<span class="hlt">induced</span> cardiac arrest in rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Adeli, S; Zarrindast, M R; Niknahad, H; Sarkar, S; Bidgoli, S A; Korani, M; Ghasemzadeh, P; Rezayat, S M</p> <p>2012-04-01</p> <p>In cardiac surgery, agents are needed to produce temporary cardiac arrest (cardioplegia). One of these agents is esmolol (ESM) which is a short-acting selective beta-1 adrenergic receptor antagonist and its overdose causes diastolic ventricular arrest. The (25) MgPMC(16) (porphyrin adducts of cyclohexil fullerene-C60) is known as a nanoparticle which has a cardioprotective effect when the heart is subjected to stressful conditions. In this study, we aimed to confirm the deleterious effects of ESM overdose on cardiac mitochondria and identify any protective effects of (25) MgPMC(16) in male Wistar rats. Esmolol 100 mg kg(-1) (LD50 = 71 mg kg(-1) ) was injected intravenously (i.v.) into tail vein to <span class="hlt">induce</span> cardiac arrest. This dose was obtained from an ESM dose-response curve which <span class="hlt">induces</span> at least 80% arrest in rats. (25) MgPMC(16) at three different doses (45, 90 and 224 mg kg(-1) ) was injected i.v. as pretreatment, eight hours before ESM injection. (25) MgCl(2) or (24) MgPMC(16) were used as controls. Following cardiac arrest, the heart was removed and the mitochondria extracted. Mitochondrial viability and the adenosine 5'-diphosphate sodium salt hydrate/Adenosine 5'-triphosphate disodium salt hydrate (ADP/ATP) ratio were measured as biomarkers of mitochondrial function. Results indicate that (25) MgPMC(16) caused a significant increase in mitochondrial viability and decrease in ADP/ATP ratio. No significant changes were seen with (24) MgPMC(16) or (25) MgCl(2) . It is concluded that cardiac arrest <span class="hlt">induced</span> by ESM overdose leads to a significant decrease in mitochondrial viability and their ATP levels, whereas pretreatment by (25) MgPMC(16) can protect mitochondria by increasing ATP level through liberation of Mg into cells and the improvement of hypoxia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23325115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23325115"><span id="translatedtitle">In vitro studies on protective effect of Glycyrrhiza glabra root extracts against cadmium-<span class="hlt">induced</span> genetic and oxidative 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>Dirican, Ebubekir; Turkez, Hasan</p> <p>2014-01-01</p> <p>Cadmium is a modern environmental contaminant that is toxic and carcinogenic. Glycyrrhiza glabra is a traditional medicinal herb which grows in the various parts of the World. Recent studies demonstrated that G. glabra has antifungal, antimicrobial, antioxidant, and powerful antiinflammatory features. The purpose of this study was to investigate the genetic safety of extracts from G. glabra and its effects on cadmium (as CdCl2) <span class="hlt">induced</span> genotoxicity. Therefore we evaluated the capability of G. glabra extract to inhibit the rate of micronucleus (MN), sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) formations <span class="hlt">induced</span> by CdCl2. Moreover, to assess the effects of G. glabra on cell viability and oxidative status, we performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and total antioxidant capacity (TAC) assays. Our results showed that there were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with CdCl2 (5 ppm) as compared to controls. However, co-application of G. glabra extract (5, 10 and 20 ppm) and CdCl2 resulted in decreases of MN and SCE rates as compared to the group treated with CdCl2 alone. Again, the results of MTT and TAC assays clearly indicated dose dependent ameliorative effects of G. glabra extracts against CdCl2 toxicity. In conclusion, this study demonstrated for the first time that G. glabra extracts provided increased resistance of DNA against CdCl2 <span class="hlt">induced</span> genetic and oxidative damage in human lymphocytes. So, the risk on target tissues of CdCl2 could be reduced and ensured early recovery from its toxicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27613321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27613321"><span id="translatedtitle">Cytotoxicity and genotoxicity <span class="hlt">induced</span> in vitro by solvent-extractable organic matter of size-segregated urban particulate matter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Velali, Ekaterini; Papachristou, Eleni; Pantazaki, Anastasia; Choli-Papadopoulou, Theodora; Argyrou, Nikoleta; Tsourouktsoglou, Theodora; Lialiaris, Stergios; Constantinidis, Alexandros; Lykidis, Dimitrios; Lialiaris, Thedore S; Besis, Athanasios; Voutsa, Dimitra; Samara, Constantini</p> <p>2016-11-01</p> <p>Three organic fractions of different polarity, including a non polar organic fraction (NPOF), a moderately polar organic fraction (MPOF), and a polar organic fraction (POF) were obtained from size-segregated (<0.49, 0.49-0.97, 0.97-3 and >3 μm) urban particulate matter (PM) samples, and tested for cytotoxicity and genotoxicity using a battery of in vitro assays. The cytotoxicity <span class="hlt">induced</span> by the organic PM fractions was measured by the mitochondrial dehydrogenase (MTT) cell viability assay applied on MRC-5 human lung epithelial cells. DNA damages were evaluated through the comet assay, determination of the poly(ADP-Ribose) polymerase (PARP) activity, and the oxidative DNA adduct 8-hydroxy-deoxyguanosine (8-OHdG) formation, while pro-inflammatory effects were assessed by determination of the tumor necrosis factor-alpha (TNF-α) mediator release. In addition, the Sister <span class="hlt">Chromatid</span> <span class="hlt">Exchange</span> (SCE) <span class="hlt">inducibility</span> of the solvent-extractable organic matter was measured on human peripheral lymphocyte. Variations of responses were assessed in relation to the polarity (hence the expected composition) of the organic PM fractions, particle size, locality, and season. Organic PM fractions were found to <span class="hlt">induce</span> rather comparable Cytotoxicity and genotoxicity of PM appeared to be rather independent from the polarity of the extractable organic PM matter (EOM) with POF often being relatively more toxic than NPOF or MPOF. All assays indicated stronger mass-normalized bioactivity for fine than coarse particles peaking in the 0.97-3 and/or the 0.49-0.97 μm size ranges. Nevertheless, the air volume-normalized bioactivity in all assays was highest for the <0.49 μm size range highlighting the important human health risk posed by the inhalation of these quasi-ultrafine particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27894685','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27894685"><span id="translatedtitle">DNA damage <span class="hlt">induced</span> by occupational and environmental exposure to miscellaneous chemicals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, Juliana</p> <p></p> <p>Epidemiological studies for hazardous situations resulting from the risk of environmental and/or occupational exposure to miscellaneous chemicals present several difficulties. Biomonitoring of human populations can provide an early detection system for the initiation of cell dysregulation in the development of cancer, which would help develop an efficient prevention program. Recently, the cytokinesis-block micronucleus (CBMN) assay in lymphocyte cells has become an important tool for assessing DNA damage in exposed populations. This is the method of choice for population-based studies of occupational and/or environmental exposure to different agents. In this review, human populations exposed to coal, dyes, paints, organic solvents in a complex mixture, and others miscellaneous chemicals were analyzed. Data from 28 studies was evaluated in relation to the effect of complex mixture exposition on micronucleus (MN) frequency. Other biomarkers and the background factors were evaluated as well, such as gender, age, or smoking habit. Most of these studies (75%) showed a significant increase of micronucleated cells to exposed groups in relation to the control groups, besides chromosomal aberrations (CA), sister <span class="hlt">chromatid</span> <span class="hlt">exchanging</span> (SCE) and comet cells (comet assay). The studies from this review about miscellaneous chemicals exposures using CBMN assay have indicated some time and dose-dependent effects. Overall, the findings suggest that the responses resulting from exposure to complex mixtures are varied and complicated. However, they are also an important mechanism of DNA damage concerning disruption of metal ion homeostasis that may lead to oxidative stress, a state where increased formation of reactive oxygen species (ROS) overwhelms body antioxidant protection and subsequently could <span class="hlt">induce</span> cancer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4081007','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4081007"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hopkins, Jessica; Bedigian, Rick; Oka, Kazuhiro; Overbeek, Paul; Murray, Steve; Jordan, Philip W.</p> <p>2014-01-01</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/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('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> </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('https://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=system+wide+information+management&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsystem%2Bwide%2Binformation%2Bmanagement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=system+wide+information+management&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsystem%2Bwide%2Binformation%2Bmanagement"><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('https://www.ncbi.nlm.nih.gov/pubmed/21988569','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21988569"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Booker, Fitzgerald; Burkey, Kent; Morgan, Patrick; Fiscus, Edwin; Jones, Alan</p> <p>2012-04-01</p> <p>Ozone (O(3)) 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 O(3) 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 O(3) 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) O(3) 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 O(3) 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 O(3) stress at physiological levels were not detectably influenced by α and β G-proteins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17912684','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17912684"><span id="translatedtitle">Strobilurin fungicides <span class="hlt">induce</span> changes in photosynthetic gas <span class="hlt">exchange</span> that do not improve water use efficiency of plants grown under conditions of water stress.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nason, Mark A; Farrar, John; Bartlett, David</p> <p>2007-12-01</p> <p>The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-<span class="hlt">induced</span> changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23275470','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23275470"><span id="translatedtitle">Gastrin <span class="hlt">induces</span> sodium-hydrogen <span class="hlt">exchanger</span> 3 phosphorylation and mTOR activation via a phosphoinositide 3-kinase-/protein kinase C-dependent but AKT-independent pathway in renal proximal tubule cells derived from a normotensive male human.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Tianbing; Jose, Pedro A</p> <p>2013-02-01</p> <p>Gastrin is natriuretic, but its renal molecular targets and signal transduction pathways are not fully known. In this study, we confirmed the existence of CCKBR (a gastrin receptor) in male human renal proximal tubule cells and discovered that gastrin <span class="hlt">induced</span> S6 phosphorylation, a downstream component of the phosphatidylinositol 3 kinase (PI3 kinase)-mammalian target of rapamycin pathway. Gastrin also increased the phosphorylation of sodium-hydrogen <span class="hlt">exchanger</span> 3 (NHE3) at serine 552, caused its internalization, and decreased its expression at the cell surface and NHE activity. The phosphorylation of NHE3 and S6 was dependent on PI3 kinases because it was blocked by 2 different PI3-kinase inhibitors, wortmannin and LY294,002. The phosphorylation of NHE3 and S6 was not affected by the protein kinase A inhibitor H-89 but was blocked by a pan-PKC (chelerythrine) and a conventional PKC (cPKC) inhibitor (Gö6976) (10 μM) and an intracellular calcium chelator, 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetra(acetoxymethyl)-ester, suggesting the importance of cPKC and intracellular calcium in the gastrin signaling pathway. The cPKC involved was probably PKCα because it was phosphorylated by gastrin. The gastrin-mediated phosphorylation of NHE3, S6, and PKCα was via phospholipase C because it was blocked by a phospholipase C inhibitor, U73122 (10 μM). The phosphorylation (activation) of AKT, which is usually upstream of mammalian target of rapamycin in the classic PI3 kinase-AKT-p70S6K signaling pathway, was not affected, suggesting that the gastrin-<span class="hlt">induced</span> phosphorylation of NHE3 and S6 is dependent on both PI3 kinase and PKCα but not AKT.</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…</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/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/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…</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/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…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=primavera&id=EJ965736','ERIC'); return false;" href="http://eric.ed.gov/?q=primavera&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://eric.ed.gov/?q=disadvantages+AND+capitalistic+AND+society&id=ED306612','ERIC'); return false;" href="http://eric.ed.gov/?q=disadvantages+AND+capitalistic+AND+society&id=ED306612"><span id="translatedtitle">Handicapping Social <span class="hlt">Exchange</span> Theory.</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>Mishler, Barbara</p> <p></p> <p>The economic theory of social <span class="hlt">exchange</span> has some serious shortcomings when applied to minorities--especially the disabled. First, it assumes dyads comprise the basic unit where <span class="hlt">exchange</span> occurs and that rewards and costs must occur at that level. Second, the model standardizes the experience of white, Western European and American males. The model…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27667326','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27667326"><span id="translatedtitle">Ion-<span class="hlt">Exchange-Induced</span> 2D-3D Conversion of HMA1-x FAx PbI3 Cl Perovskite into a High-Quality MA1-x FAx PbI3 Perovskite.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Ge; Zhang, Taiyang; Guo, Nanjie; Xu, Feng; Qian, Xufang; Zhao, Yixin</p> <p>2016-10-17</p> <p>High-quality phase-pure MA1-x FAx PbI3 planar films (MA=methylammonium, FA=formamidinium) with extended absorption and enhanced thermal stability are difficult to deposit by regular simple solution chemistry approaches owing to crystallization competition between the easy-to-crystallize but unwanted δ-FAPbI3 /MAPbI3 and FAx MA1-x PbI3 requiring rigid crystallization conditions. Here A 2D-3D conversion to transform compact 2D mixed composition HMA1-x FAx PbI3 Cl perovskite precursor films into 3D MA1-x FAx PbI3 (x=0.1-0.9) perovskites is presented. The designed Cl/I and H/FA(MA) ion <span class="hlt">exchange</span> reaction <span class="hlt">induced</span> fast transformation of compact 2D perovskite film, helping to form the phase-pure and high quality MA1-x FAx PbI3 without δ-FAPbI3 and MAPbI3 impurity. In all, we successfully developed a facile one-step method to fabricate high quality phase-pure MA1-x FAx PbI3 (x=0.1-0.9) perovskite films by 2D-3D conversion of HMA1-x FAx PbI3 Cl perovskite. This 2D-3D conversion is a promising strategy for lead halide perovskite fabrication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22443764','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22443764"><span id="translatedtitle">Fully converged integral cross sections of collision <span class="hlt">induced</span> dissociation, four-center, and single <span class="hlt">exchange</span> reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Hongwei; Lu, Yunpeng; Lee, Soo-Y</p> <p>2012-03-21</p> <p>The initial state selected time-dependent wave packet method was employed to calculate the integral cross sections for the H(2) + D(2) reaction with and without the centrifugal sudden (CS) approximation by including all important K (the projection of the total angular momentum on the body-fixed axis) blocks. With a full-dimensional model, the first fully converged coupled-channel (CC) cross sections for different competitive processes from the ground rotational state were obtained: collision <span class="hlt">induced</span> dissociation (CID), four-center (4C) reaction and single <span class="hlt">exchange</span> (SE) reaction. The effect of the total angular momentum J on the reaction dynamics of H(2) + D(2) and the accuracy of the CS approximation have also been studied. It was found that the CID and SE processes occur in a wide range of J values while the 4C process can only take place in a narrow window of J values. For this reason, the CC cross section for the 4C channel is merely comparable to the SE channel. A comparison of the integral cross sections from CC and CS calculations showed that the CS approximation works well for the CID process but not for the 4C and SE processes, and the discrepancy between the CC and CS cross sections grows larger as the translational energy and/or the vibrational energy increase(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16101287','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16101287"><span id="translatedtitle">Temperature-<span class="hlt">induced</span> conformational change at the catalytic site of Sulfolobus solfataricus alcohol dehydrogenase highlighted by Asn249Tyr substitution. A hydrogen/deuterium <span class="hlt">exchange</span>, kinetic, and fluorescence quenching study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Secundo, Francesco; Russo, Consiglia; Giordano, Antonietta; Carrea, Giacomo; Rossi, Mosè; Raia, Carlo A</p> <p>2005-08-23</p> <p>A combination of hydrogen/deuterium <span class="hlt">exchange</span>, fluorescence quenching, and kinetic studies was used to acquire experimental evidence for the crystallographically hypothesized increase in local flexibility which occurs in thermophilic NAD(+)-dependent Sulfolobus solfataricus alcohol dehydrogenase (SsADH) upon substitution Asn249Tyr. The substitution, located at the adenine-binding site, proved to decrease the affinity for both coenzyme and substrate, rendering the mutant enzyme 6-fold more active when compared to the wild-type enzyme [Esposito et al. (2003) FEBS Lett. 539, 14-18]. The amide H/D <span class="hlt">exchange</span> data show that the wild-type and mutant enzymes have similar global flexibility at 22 and 60 degrees C. However, the temperature dependence of the Stern-Volmer constant determined by acrylamide quenching shows that the increase in temperature affects the local flexibility differently, since the K(SV) increment is significantly higher for the wild-type than for the mutant enzyme over the range 18-45 degrees C. Interestingly, the corresponding van't Hoff plot (log K(SV) vs 1/T) proves nonlinear for the apo and holo wild-type and apo mutant enzymes, with a break at approximately 45 degrees C in all three cases due to a conformational change affecting the tryptophan microenvironment experienced by the quencher molecules. The Arrhenius and van't Hoff plots derived from the k(cat) and K(M) thermodependence measured with cyclohexanol and NAD(+) at different temperatures display an abrupt change of slope at 45-50 degrees C. This proves more pronounced in the case of the mutant enzyme compared to the wild-type enzyme due to a conformational change in the structure rather than to an overlapping of two or more rate-limiting reaction steps with different temperature dependencies of their rate constants. Three-dimensional analysis indicates that the observed conformational change <span class="hlt">induced</span> by temperature is associated with the flexible loops directly involved in the substrate and</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/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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007LNCS.4886..163T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007LNCS.4886..163T"><span id="translatedtitle">Cryptographic 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>While transparency in financial markets should enhance liquidity, its exploitation by unethical and parasitic traders discourages others from fully embracing disclosure of their own information. Traders exploit both the private information in upstairs markets used to trade large orders outside traditional <span class="hlt">exchanges</span> and the public information present in <span class="hlt">exchanges</span>' quoted limit order books. Using homomorphic cryptographic protocols, market designers can create "partially transparent" markets in which every matched trade is provably correct and only beneficial information is revealed. In a cryptographic securities <span class="hlt">exchange</span>, market operators can hide information to prevent its exploitation, and still prove facts about the hidden information such as bid/ask spread or market depth.</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> </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('https://ntrs.nasa.gov/search.jsp?R=19800000081&hterms=wire+heat+transfer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwire%2Bheat%2Btransfer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800000081&hterms=wire+heat+transfer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwire%2Bheat%2Btransfer"><span id="translatedtitle">Compact, super 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>Fortini, A.; Kazaroff, J. M.</p> <p>1980-01-01</p> <p>Heat <span class="hlt">exchanger</span> uses porous media to enhance heat transfer through walls of cooling channels, thereby lowering wall temperature. Porous media within cooling channel increases internal surface area from which heat can be transferred to coolant. Comparison data shows wall has lower temperature and coolant has higher temperature when porous medium is used within heat <span class="hlt">exchanger</span>. Media can be sintered powedered metal, metal fibers, woven wire layers, or any porous metal having desired permeability and porosity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23737179','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23737179"><span id="translatedtitle">Hibernation and 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>Milsom, William K; Jackson, Donald C</p> <p>2011-01-01</p> <p>Hibernation in endotherms and ectotherms is characterized by an energy-conserving metabolic depression due to low body temperatures and poorly understood temperature-independent mechanisms. Rates of gas <span class="hlt">exchange</span> are correspondly reduced. In hibernating mammals, ventilation falls even more than metabolic rate leading to a relative respiratory acidosis that may contribute to metabolic depression. Breathing in some mammals becomes episodic and in some small mammals significant apneic gas <span class="hlt">exchange</span> may occur by passive diffusion via airways or skin. In ectothermic vertebrates, extrapulmonary gas <span class="hlt">exchange</span> predominates and in reptiles and amphibians hibernating underwater accounts for all gas <span class="hlt">exchange</span>. In aerated water diffusive <span class="hlt">exchange</span> permits amphibians and many species of turtles to remain fully aerobic, but hypoxic conditions can challenge many of these animals. Oxygen uptake into blood in both endotherms and ectotherms is enhanced by increased affinity of hemoglobin for O₂ at low temperature. Regulation of gas <span class="hlt">exchange</span> in hibernating mammals is predominately linked to CO₂/pH, and in episodic breathers, control is principally directed at the duration of the apneic period. Control in submerged hibernating ectotherms is poorly understood, although skin-diffusing capacity may increase under hypoxic conditions. In aerated water blood pH of frogs and turtles either adheres to alphastat regulation (pH ∼8.0) or may even exhibit respiratory alkalosis. Arousal in hibernating mammals leads to restoration of euthermic temperature, metabolic rate, and gas <span class="hlt">exchange</span> and occurs periodically even as ambient temperatures remain low, whereas body temperature, metabolic rate, and gas <span class="hlt">exchange</span> of hibernating ectotherms are tightly linked to ambient temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7295355','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7295355"><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>1992-07-09</p> <p>The purpose of this contract has been to explore the limits of miniaturization of heat <span class="hlt">exchangers</span> with the goals of (1) improving the theoretical understanding of laminar heat <span class="hlt">exchangers</span>, (2) evaluating various manufacturing difficulties, and (3) identifying major applications for the technology. A low-cost, ultra-compact heat <span class="hlt">exchanger</span> could have an enormous impact on industry in the areas of cryocoolers and energy conversion. Compact cryocoolers based on the reverse Brayton cycle (RBC) would become practical with the availability of compact heat <span class="hlt">exchangers</span>. Many experts believe that hardware advances in personal computer technology will rapidly slow down in four to six years unless lowcost, portable cryocoolers suitable for the desktop supercomputer can be developed. Compact refrigeration systems would permit dramatic advances in high-performance computer work stations with conventional'' microprocessors operating at 150 K, and especially with low-cost cryocoolers below 77 K. NASA has also expressed strong interest in our MTS <span class="hlt">exchanger</span> for space-based RBC cryocoolers for sensor cooling. 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://adsabs.harvard.edu/abs/2011JHEP...10..108G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHEP...10..108G"><span id="translatedtitle">Reggeon <span class="hlt">exchange</span> from gauge/gravity duality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giordano, Matteo; Peschanski, Robi</p> <p>2011-10-01</p> <p>We perform the analysis of quark-antiquark Reggeon <span class="hlt">exchange</span> in meson-meson scattering, in the framework of the gauge/gravity correspondence in a confining background. On the gauge theory side, Reggeon <span class="hlt">exchange</span> is described as quark-antiquark <span class="hlt">exchange</span> in the t channel between fast projectiles. The corresponding amplitude is represented in terms of Wilson loops running along the trajectories of the constituent quarks and antiquarks. The paths of the <span class="hlt">exchanged</span> fermions are integrated over, while the "spectator" fermions are dealt with in an eikonal approximation. On the gravity side, we follow a previously proposed approach, and we evaluate the Wilson-loop expectation value by making use of gauge/gravity duality for a generic confining gauge theory. The amplitude is obtained in a saddle-point approximation through the determination near the confining horizon of a Euclidean "minimal surface with floating boundaries", i.e., by fixing the trajectories of the <span class="hlt">exchanged</span> quark and antiquark by means of a minimisation procedure, which involves both area and length terms. After discussing, as a warm-up exercise, a simpler problem on a plane involving a soap film with floating boundaries, we solve the variational problem relevant to Reggeon <span class="hlt">exchange</span>, in which the basic geometry is that of a helicoid. A compact expression for the Reggeon-<span class="hlt">exchange</span> amplitude, including the effects of a small fermion mass, is then obtained through analytic continuation from Euclidean to Minkowski space-time. We find in particular a linear Regge trajectory, corresponding to a Regge-pole singularity supplemented by a logarithmic cut <span class="hlt">induced</span> by the non-zero quark mass. The analytic continuation leads also to companion contributions, corresponding to the convolution of the same Reggeon-<span class="hlt">exchange</span> amplitude with multiple elastic rescattering interactions between the colliding mesons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/209888','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/209888"><span id="translatedtitle">Low-sister-<span class="hlt">chromatid-exchange</span> Bloom syndrome cell lines: An important new tool for mapping the basic genetic defect in Bloom syndrome and for unraveling the biology of human tumor development</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weksberg, R.</p> <p>1995-11-01</p> <p>Bloom syndrome (BS) is a rare autosomal recessive disorder characterized by growth failure, immunodeficiency, and a predisposition to cancer. A variety of malignancies, including both carcinomas and leukemias, occur by age 30 years in {approximately}25% of patients. Cells from BS patients exhibit excessive chromosome breakage and rearrangements, suggesting a defect in DNA metabolism. Multiple defects of DNA replication and cell-cycle progression have been documented. Activity of several enzymes involved in DNA replication is altered, including that of DNA ligase I, uracil-DNA glycosylase, and super-oxide dismutase. Replication fork progression is retarded, and an unusual size distribution of DNA replication intermediates is observed. Cell-cycle kinetic studies show that BS fibroblasts are arrested in the G2 phase and often have an abnormally prolonged G1 phase. However, all these known defects in DNA metabolism appear to be secondary to the elusive fundamental genetic defect in BS. 30 refs.</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.osti.gov/scitech/biblio/5462064','SCIGOV-STC'); return false;" href="https://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('https://www.osti.gov/scitech/biblio/22391356','SCIGOV-STC'); return false;" href="https://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('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/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('https://www.ncbi.nlm.nih.gov/pubmed/21368764','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21368764"><span id="translatedtitle">Chromosome length influences replication-<span class="hlt">induced</span> topological stress.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kegel, Andreas; Betts-Lindroos, Hanna; Kanno, Takaharu; Jeppsson, Kristian; Ström, Lena; Katou, Yuki; Itoh, Takehiko; Shirahige, Katsuhiko; Sjögren, Camilla</p> <p>2011-03-17</p> <p>During chromosome duplication the parental DNA molecule becomes overwound, or positively supercoiled, in the region ahead of the advancing replication fork. To allow fork progression, this superhelical tension has to be removed by topoisomerases, which operate by introducing transient DNA breaks. Positive supercoiling can also be diminished if the advancing fork rotates along the DNA helix, but then sister <span class="hlt">chromatid</span> intertwinings form in its wake. Despite these insights it remains largely unknown how replication-<span class="hlt">induced</span> superhelical stress is dealt with on linear, eukaryotic chromosomes. Here we show that this stress increases with the length of Saccharomyces cerevisiae chromosomes. This highlights the possibility that superhelical tension is handled on a chromosome scale and not only within topologically closed chromosomal domains as the current view predicts. We found that inhibition of type I topoisomerases leads to a late replication delay of longer, but not shorter, chromosomes. This phenotype is also displayed by cells expressing mutated versions of the cohesin- and condensin-related Smc5/6 complex. The frequency of chromosomal association sites of the Smc5/6 complex increases in response to chromosome lengthening, chromosome circularization, or inactivation of topoisomerase 2, all having the potential to increase the number of sister <span class="hlt">chromatid</span> intertwinings. Furthermore, non-functional Smc6 reduces the accumulation of intertwined sister plasmids after one round of replication in the absence of topoisomerase 2 function. Our results demonstrate that the length of a chromosome influences the need of superhelical tension release in Saccharomyces cerevisiae, and allow us to propose a model where the Smc5/6 complex facilitates fork rotation by sequestering nascent <span class="hlt">chromatid</span> intertwinings that form behind the replication machinery.</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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15668106','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15668106"><span id="translatedtitle">V79-hCYP2E1-hSULT1A1, a cell line for the sensitive detection of genotoxic effects <span class="hlt">induced</span> by carbohydrate pyrolysis products and other food-borne chemicals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glatt, Hansruedi; Schneider, Heiko; Liu, Yungang</p> <p>2005-02-07</p> <p>We recently constructed a Chinese hamster V79-derived cell line that stably expresses human cytochrome P450 (CYP) 2E1 and human sulphotransferase (SULT) 1A1. These enzymes are involved in the bioactivation of numerous promutagens/procarcinogens, but are not taken into account in standard in vitro mutagenicity assays. Various carbohydrate pyrolysis products and other food contaminants that <span class="hlt">induce</span> tumours or preneoplastic lesions in laboratory animals are inactive or only weakly active in standard in vitro genotoxicity assays. This is the case for acrylamide, furan, 5-hydroxymethylfurfural, nitrofen and N-nitrosodimethylamine. These compounds were investigated for induction of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) in V79-hCYP2E1-hSULT1A1 cells. All test compounds showed positive results over a wide concentration range, starting at 0.01 microM for N-nitrosodimethylamine, 3 microM for furan, 12.5 microM for nitrofen, 20 microM for 5-hydroxymethylfurfural, and 200 microM for acrylamide. The concentration-response curve of furan was unusual, as this compound <span class="hlt">induced</span> a statistically significant, but rather constant and weak increase in SCE over an extremely wide concentration range (3-16,000 microM). Furan was slightly less active, whereas the remaining compounds were much less active in the parental V79 cell line than in V79-hCYP2E1-hSULT1A1 cells. Compared to many other genotoxic effects, the study of SCE only requires small numbers of cells (and incubation volumes) and usually is detected even at low concentrations of the genotoxicant. Therefore, induction of SCE in V79-hCYP2E1-hSULT1A1 cells may be useful in the genotoxicity testing of preparations of heated food and in their bioassay-directed fractionation.</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/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.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/2060/20080005075','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://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/2060/20110012957','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('https://www.osti.gov/scitech/biblio/7050066','SCIGOV-STC'); return false;" href="https://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> </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://adsabs.harvard.edu/abs/2012APS..MAR.W8007D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MAR.W8007D"><span id="translatedtitle">Universal <span class="hlt">exchange</span>-driven phonon splitting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deisenhofer, Joachim; Kant, Christian; Schmidt, Michael; Wang, Zhe; Mayr, Franz; Tsurkan, Vladimir; Loidl, Alois</p> <p>2012-02-01</p> <p>We report on a linear dependence of the phonon splitting on the non-dominant <span class="hlt">exchange</span> coupling Jnd in the antiferromagnetic monoxides MnO, Fe0.92O, CoO and NiO, and in the highly frustrated antiferromagnetic spinels CdCr2O4, MgCr2O4 and ZnCr2O4. For the monoxides our results directly confirm the theoretical prediction of a predominantly <span class="hlt">exchange</span> <span class="hlt">induced</span> splitting of the zone-centre optical phonon [1,2]. We find the linear relation δφ= βJndS^2 with slope β = 3.7. This relation also holds for a very different class of systems, namely the highly frustrated chromium spinels. Our finding suggests a universal dependence of the <span class="hlt">exchange-induced</span> phonon splitting at the antiferromagnetic transition on the non-dominant <span class="hlt">exchange</span> coupling [3].[4pt] [1] S. Massidda et al., Phys. Rev. Lett. 82, 430 (1999).[0pt] [2] W. Luo et al., Solid State Commun. 142, 504 (2007).[0pt] [3] Ch. Kant et al., arxiv:1109.4809.</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://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…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5758003','SCIGOV-STC'); return false;" href="https://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://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://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://eric.ed.gov/?q=convection&pg=6&id=EJ452044','ERIC'); return false;" href="http://eric.ed.gov/?q=convection&pg=6&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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED475319.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED475319.pdf"><span id="translatedtitle">Research <span class="hlt">Exchange</span>, 2002.</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>Research Exchange, 2002</p> <p>2002-01-01</p> <p>These three issues of the "Research <span class="hlt">Exchange</span>" focus on how better to conduct disability research and disseminate research results. The first issue examines the topic of human subject/human research participant protection, with a focus on research funded through the National Institute on Disability and Rehabilitation Research (NIDRR). It…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=coastal+AND+ecosystem&pg=2&id=EJ346259','ERIC'); return false;" href="http://eric.ed.gov/?q=coastal+AND+ecosystem&pg=2&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…</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…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991mshe.reptR....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991mshe.reptR....D"><span id="translatedtitle">Microtube strip 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>Doty, F. D.</p> <p>1991-04-01</p> <p>During the last quarter, Doty Scientific, Inc. (DSI) continued to make progress on the microtube strip (MTS) heat <span class="hlt">exchangers</span>. The team has begun a heat <span class="hlt">exchanger</span> stress analysis; however, they have been concentrating the bulk of their analytical energies on a computational fluid dynmaics (CFD) model to determine the location and magnitude of shell-side flow maldistribution which decreases heat <span class="hlt">exchanger</span> effectiveness. DSI received 120 fineblanked tubestrips from Southern Fineblanking (SFB) for manufacturing process development. Both SFB and NIST provided inspection reports of the tubestrips. DSI completed the tooling required to encapsulate a tube array and press tubestrips on the array. Pressing the tubestrips on tube arrays showed design deficiencies both in the tubestrip design and the tooling design. DSI has a number of revisions in process to correct these deficiencies. The research effort has identified a more economical fusible alloy for encapsulating the tube array, and determined the parameters required to successfully encapsulate the tube array with the new alloy. A more compact MTS heat <span class="hlt">exchanger</span> bank was designed.</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,…</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://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('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('http://adsabs.harvard.edu/abs/2017PhyA..469..102H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..469..102H"><span id="translatedtitle"><span class="hlt">Exchange</span> rate rebounds after foreign <span class="hlt">exchange</span> market interventions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoshikawa, Takeshi</p> <p>2017-03-01</p> <p>This study examined the rebounds in the <span class="hlt">exchange</span> rate after foreign <span class="hlt">exchange</span> intervention. When intervention is strongly effective, the <span class="hlt">exchange</span> rate rebounds at next day. The effect of intervention is reduced slightly by the rebound after the intervention. The <span class="hlt">exchange</span> rate might have been 67.12-77.47 yen to a US dollar without yen-selling/dollar-purchasing intervention of 74,691,100 million yen implemented by the Japanese government since 1991, in comparison to the actual <span class="hlt">exchange</span> rate was 103.19 yen to the US dollar at the end of March 2014.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994JAP....75.2289M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994JAP....75.2289M"><span id="translatedtitle">Intergranular <span class="hlt">exchange</span> coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muller, M. W.; Indeck, R. S.</p> <p>1994-02-01</p> <p>We evaluate the <span class="hlt">exchange</span> interaction between neighboring grains of a polycrystalline magnetic material with uniaxial magnetocrystalline anisotropy, based on the energy of the domain wall formed at the portion of the interface in atomic contact. The analysis suggests that previous work [J.-G. Zhu and H. N. Bertram, in Solid State Physics Vol. 46, edited by H. Ehrenreich and T. Turnbull (Academic, San Diego, 1992)] may underestimate the interaction, and it predicts a different dependence on grain size.</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> </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('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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19539779','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19539779"><span id="translatedtitle">Inhalation of formaldehyde does not <span class="hlt">induce</span> systemic genotoxic effects in rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Speit, Günter; Zeller, Jasmin; Schmid, Oliver; Elhajouji, Azeddine; Ma-Hock, Lan; Neuss, Simone</p> <p>2009-01-01</p> <p>Male Fischer-344 rats were exposed to formaldehyde (FA) by inhalation for 4 weeks (6 h/day, 5 days/week). Groups of six rats each were exposed to the target concentrations of 0, 0.5, 1, 2, 6, 10 and 15 ppm. Potential systemic genotoxic effects were investigated as part of a comprehensive study on local and systemic toxic and genotoxic effects. For this purpose, peripheral blood samples were obtained by puncturing the retro-orbital venous plexus at the end of the exposure period. Blood sampling was carried out in a randomized sequence and samples were coded by sequence number to ensure blind evaluation. Blood samples were used for the comet assay, the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> test (SCE test) and the micronucleus test (MNT). DNA migration in the comet assay was measured both directly and after irradiation of the blood samples with 2 Gy gamma-radiation. The latter modification of the comet assay was included to increase its sensitivity for the detection of DNA-protein cross-links (DPX). The following positive control groups were included: one group (six animals) was treated with 50mg/kg methyl methanesulfonate (MMS) once by gavage 4h before blood sampling. Another group (six animals) was treated twice orally with 10mg/kg cyclophosphamide (CP) with an interval of 24 h. The last application of CP was 24h before blood sampling. For the comet assay, four slides were analysed from each blood sample, two without and two with irradiation. From each slide, 50 randomly selected cells were measured by image analysis, and tail intensity (% tail DNA) and tail moment were evaluated. For the SCE test, blood was cultured for 56 h in the presence of BrdU (10 microg/ml for the last 35 h) and SCE were counted in 30 second-division metaphases per sample. The MNT with peripheral blood was performed according to the instructions for the micronucleus analysis kit MICROFLOW (Litron Laboratories). Approximately 20,000 cells per sample were analysed by flow cytometry and the percentage of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16527753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16527753"><span id="translatedtitle">Scraped surface heat <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>Rao, Chetan S; Hartel, Richard W</p> <p>2006-01-01</p> <p>Scraped surface heat <span class="hlt">exchangers</span> (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat <span class="hlt">exchange</span>, the scraper blades also provide simultaneous mixing and agitation. Heat <span class="hlt">exchange</span> for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6151417','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6151417"><span id="translatedtitle">Optimizing <span class="hlt">exchanger</span> design early</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lacunza, M.; Vaschetti, G.; Campana, H.</p> <p>1987-08-01</p> <p>It is not practical for process engineers and designers to make a rigorous economic evaluation for each component of a process due to the loss of time and money. But, it's very helpful and useful to have a method for a quick design evaluation of heat <span class="hlt">exchangers</span>, considering their important contribution to the total fixed investment in a process plant. This article is devoted to this subject, and the authors present a method that has been proved in some design cases. Linking rigorous design procedures with a quick cost-estimation method provides a good technique for obtaining the right heat <span class="hlt">exchanger</span>. The cost will be appropriate, sometimes not the lowest because of design restrictions, but a good approach to the optimum in an earlier process design stage. The authors intend to show the influence of the design variables in a shell and tube heat <span class="hlt">exchanger</span> on capital investment, or conversely, taking into account the general limiting factors of the process such as thermodynamics, operability, corrosion, etc., and/or from the mechanical design of the calculated unit. The last is a special consideration for countries with no access to industrial technology or with difficulties in obtaining certain construction materials or equipment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14524747','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14524747"><span id="translatedtitle"><span class="hlt">Exchange</span>-driven growth.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ben-Naim, E; Krapivsky, P L</p> <p>2003-09-01</p> <p>We study a class of growth processes in which clusters evolve via <span class="hlt">exchange</span> of particles. We show that depending on the rate of <span class="hlt">exchange</span> there are three possibilities: (I) Growth-clusters grow indefinitely, (II) gelation-all mass is transformed into an infinite gel in a finite time, and (III) instant gelation. In regimes I and II, the cluster size distribution attains a self-similar form. The large size tail of the scaling distribution is Phi(x) approximately exp(-x(2-nu)), where nu is a homogeneity degree of the rate of <span class="hlt">exchange</span>. At the borderline case nu=2, the distribution exhibits a generic algebraic tail, Phi(x) approximately x(-5). In regime III, the gel nucleates immediately and consumes the entire system. For finite systems, the gelation time vanishes logarithmically, T approximately [lnN](-(nu-2)), in the large system size limit N--> infinity. The theory is applied to coarsening in the infinite range Ising-Kawasaki model and in electrostatically driven granular layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28060322','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28060322"><span id="translatedtitle">Analysis of the Ambient Particulate Matter-<span class="hlt">induced</span> Chromosomal Aberrations Using an In Vitro System.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miousse, Isabelle R; Koturbash, Igor; Chalbot, Marie-Cécile; Hauer-Jensen, Martin; Kavouras, Ilias; Pathak, Rupak</p> <p>2016-12-21</p> <p>Exposure to particulate matter (PM) is a major world health concern, which may damage various cellular components, including the nuclear genetic material. To assess the impact of PM on nuclear genetic integrity, structural chromosomal aberrations are scored in the metaphase spreads of mouse RAW264.7 macrophage cells. PM is collected from ambient air with a high volume total suspended particles sampler. The collected material is solubilized and filtered to retain the water-soluble, fine portion. The particles are characterized for chemical composition by nuclear magnetic resonance (NMR) spectroscopy. Different concentrations of particle suspension are added onto an in vitro culture of RAW264.7 mouse macrophages for a total exposure time of 72 hr, along with untreated control cells. At the end of exposure, the culture is treated with colcemid to arrest cells in metaphase. Cells are then harvested, treated with hypotonic solution, fixed in acetomethanol, dropped onto glass slides and finally stained with Giemsa solution. Slides are examined to assess the structural chromosomal aberrations (CAs) in metaphase spreads at 1,000X magnification using a bright-field microscope. 50 to 100 metaphase spread are scored for each treatment group. This technique is adapted for the detection of structural chromosomal aberrations (CAs), such as <span class="hlt">chromatid</span>-type breaks, <span class="hlt">chromatid</span>-type <span class="hlt">exchanges</span>, acentric fragments, dicentric and ring chromosomes, double minutes, endoreduplication, and Robertsonian translocations in vitro after exposure to PM. It is a powerful method to associate a well-established cytogenetic endpoint to epigenetic alterations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLA..381.1169Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLA..381.1169Z"><span id="translatedtitle">Long range ferromagnetism in (Zn, Mn, Li)Se with competition between double <span class="hlt">exchange</span> and p-d <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>Zhu, Y.; Liu, T.; Zhang, X. Y.; Pan, Y. F.; Wei, X. Y.; Ma, C. L.; Shi, D. N.; Fan, J. Y.</p> <p>2017-04-01</p> <p>In this paper, we elucidate the mechanism for Li co-dopant <span class="hlt">induced</span> enhancement of the ferromagnetism in 2 × 2 × 2 and 3 × 3 × 3 cubic (Zn, Mn)Se using density functional calculations. The doping atoms tend to congregate together according to the ferromagnetic (FM) energy. All configurations are strongly FM ones due to double <span class="hlt">exchange</span> (DE) and p-d <span class="hlt">exchange</span> (PE). DE and PE are shown in the partial density of states. The hole is uniformly distributed in the cubic (Zn, Mn, Li)Se, and it is the one and only parameter to decide the <span class="hlt">exchange</span> energy, when impurity atoms stay further away from each other. The average <span class="hlt">exchange</span> energy of these configurations is considered to be a function of the square root of the hole concentration. The fitting data to a polynomial function shows that DE and PE have roles of similar importance in the <span class="hlt">exchange</span> energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770003526','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770003526"><span id="translatedtitle">Lightweight Long Life 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>Moore, E. K.</p> <p>1976-01-01</p> <p>A shuttle orbiter flight configuration aluminum heat <span class="hlt">exchanger</span> was designed, fabricated, and tested. The heat <span class="hlt">exchanger</span> utilized aluminum clad titanium composite parting sheets for protection against parting sheet pin hole corrosion. The heat <span class="hlt">exchanger</span>, which is fully interchangeable with the shuttle condensing heat <span class="hlt">exchanger</span>, includes slurpers (a means for removing condensed water from the downstream face of the heat <span class="hlt">exchanger</span>), and both the core air passes and slurpers were hydrophilic coated to enhance wettability. The test program included performance tests which demonstrated the adequacy of the design and confirmed the predicted weight savings.</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('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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=546951','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=546951"><span id="translatedtitle">Gas <span class="hlt">Exchange</span> of Algae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ammann, Elizabeth C. B.; Lynch, Victoria H.</p> <p>1967-01-01</p> <p>The oxygen production of a photosynthetic gas <span class="hlt">exchanger</span> containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present within the culture unit. The internal carbon dioxide concentrations were obtained by manipulating the entrance gas concentration and the flow rate. Carbon dioxide percentages were monitored by means of electrodes placed directly in the nutrient medium. The concentration of carbon dioxide in the nutrient medium which produced maximal photosynthesis was in the range of 1.5 to 2.5% by volume. Results were unaffected by either the level of carbon dioxide in the entrance gas or the rate of gas flow. Entrance gases containing 2% carbon dioxide flowing at 320 ml/min, 3% carbon dioxide at 135 ml/min, and 4% carbon dioxide at 55 ml/min yielded optimal carbon dioxide concentrations in the particular unit studied. By using carbon dioxide electrodes implanted directly in the gas <span class="hlt">exchanger</span> to optimize the carbon dioxide concentration throughout the culture medium, it should be possible to design more efficient large-scale units. PMID:4382391</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://www.dtic.mil/docs/citations/ADA181755','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA181755"><span id="translatedtitle">Genotoxicity of Dyes Present in Colored Smoke Munitions.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1986-07-07</p> <p>sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, and chromosome aberration induction in mammalian cells. The dyes evaluated in the report include Solvent Red 24, Solvent...<span class="hlt">Chromatid</span> <span class="hlt">Exchanges</span> from Dyes ... .............. .... 255 Chromosome Aberrations from Dyes .... ................ .... 26 RESULTS...77 Mammalian Cell Mutagenicity of Dyes .... ............... .... 79 Sister <span class="hlt">Chromatid</span> <span class="hlt">Exchanges</span> from Dyes .............. 91 Chromosome</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1521837','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1521837"><span id="translatedtitle">Genotoxicity studies of the food additive ester gum.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mukherjee, A; Agarwal, K; Chakrabarti, J</p> <p>1992-07-01</p> <p>Ester gum (EG) is used in citrus oil-based beverage flavourings as a weighting or colouring agent. In the present study, concentrations of 50, 100 and 150 mg/kg body weight were administered orally to male Swiss albino mice, and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> and chromosomal aberration were used as the cytogenetic endpoints to determine the genotoxic and clastogenic potential of the food additive. Although EG was weakly clastogenic and could <span class="hlt">induce</span> a marginal increase in sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> frequencies, it was not a potential health hazard at the doses tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6420524','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6420524"><span id="translatedtitle">Ion <span class="hlt">exchange</span> technology assessment report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duhn, E.F.</p> <p>1992-01-01</p> <p>In the execution of its charter, the SRS Ion <span class="hlt">Exchange</span> Technology Assessment Team has determined that ion <span class="hlt">exchange</span> (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion <span class="hlt">exchange</span> media available today offer the ability to design ion <span class="hlt">exchange</span> processing systems tailored to the unique physical and chemical properties of SRS soluble HLW's. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion <span class="hlt">exchange</span> and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion <span class="hlt">exchange</span> technology assessment and conclusions of the task team.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10165109','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10165109"><span id="translatedtitle">Ion <span class="hlt">exchange</span> technology assessment report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duhn, E.F.</p> <p>1992-12-31</p> <p>In the execution of its charter, the SRS Ion <span class="hlt">Exchange</span> Technology Assessment Team has determined that ion <span class="hlt">exchange</span> (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion <span class="hlt">exchange</span> media available today offer the ability to design ion <span class="hlt">exchange</span> processing systems tailored to the unique physical and chemical properties of SRS soluble HLW`s. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion <span class="hlt">exchange</span> and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion <span class="hlt">exchange</span> technology assessment and conclusions of the task team.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080012237','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080012237"><span id="translatedtitle">Ion-<span class="hlt">exchange</span> hollow fibers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rembaum, Alan (Inventor); Yen, Shiao-Ping S. (Inventor); Klein, Elias (Inventor)</p> <p>1977-01-01</p> <p>An ion-<span class="hlt">exchange</span> hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-<span class="hlt">exchange</span> resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-<span class="hlt">exchange</span> capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-<span class="hlt">exchange</span> hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080004196','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080004196"><span id="translatedtitle">Ion-<span class="hlt">exchange</span> hollow fibers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rembaum, Alan (Inventor); Yen, Shiao-Ping S. (Inventor); Klein, Elias (Inventor)</p> <p>1980-01-01</p> <p>An ion-<span class="hlt">exchange</span> hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-<span class="hlt">exchange</span> resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-<span class="hlt">exchange</span> capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-<span class="hlt">exchange</span> hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810010717','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810010717"><span id="translatedtitle">Ion-<span class="hlt">exchange</span> hollow fibers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rembaum, A.; Yen, S. P. S.; Klein, E. (Inventor)</p> <p>1976-01-01</p> <p>An ion-<span class="hlt">exchange</span> hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, crosslinked, ion-<span class="hlt">exchange</span> resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-<span class="hlt">exchange</span> capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-<span class="hlt">exchange</span> hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080008777','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080008777"><span id="translatedtitle">Monogroove liquid 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>Brown, Richard F. (Inventor); Edelstein, Fred (Inventor)</p> <p>1990-01-01</p> <p>A liquid supply control is disclosed for a heat transfer system which transports heat by liquid-vapor phase change of a working fluid. An assembly (10) of monogroove heat pipe legs (15) can be operated automatically as either heat acquisition devices or heat discharge sources. The liquid channels (27) of the heat pipe legs (15) are connected to a reservoir (35) which is filled and drained by respective filling and draining valves (30, 32). Information from liquid level sensors (50, 51) on the reservoir (35) is combined (60) with temperature information (55) from the liquid heat <span class="hlt">exchanger</span> (12) and temperature information (56) from the assembly vapor conduit (42) to regulate filling and draining of the reservoir (35), so that the reservoir (35) in turn serves the liquid supply/drain needs of the heat pipe legs (15), on demand, by passive capillary action (20, 28).</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. 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