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Sample records for chromatid exchange induced

  1. SISTER CHROMATID EXCHANGES IN MAMMALIAN MEIOTIC CHROMOSOMES

    EPA Science Inventory

    Very little is known about sister chromatid exchanges (SCEs) in meiotic cells--only that they occur (1) and reveal frequency and distribution patterns apparently unaffected by cross-over (CO) exchange conditions in those cells; (2) unfortunately, the number of studies from which ...

  2. 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)

  3. 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.

  4. 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.

  5. TISSUE-SPECIFIC SISTER CHROMATID EXCHANGE ANALYSES IN MUTAGEN-CARCINOGEN EXPOSED ANIMALS

    EPA Science Inventory

    The phenomenon of sister chromatid exchange (SCE) has been extensively reviewed. Sister chromatid exchanges are intrachromosomal events, wherein segments of DNA are reciprocally swapped between the chromatids. They are most easily studied with 5-bromodeoxyuridine (BrdU) dye metho...

  6. Evidence for an indirect effect of radiation on mammalian chromosomes. III. UV- and x-ray-induced sister chromatid exchanges in heterokaryons

    SciTech Connect

    Graves, J.A.; Kellow, G.N.

    1983-04-01

    The hypothesis that chromosomes may be damaged indirectly by radiation was examined by assaying sister chromatid exchange, (SCE) frequency in heterokaryons between irradiated and unirradiated mouse and Chinese hamster cells. One cell line was UV or x irradiated, then fused to unirradiated BrdU-labeled cells of the other line; SCEs in the unirradiated set were scored in heterokaryons. A dose-dependent increase was consistently observed; the magnitude of which suggested that 25% of UV-induced and up to 60% of x-ray-induced SCEs are indirectly induced. Medium transfer experiments, cell mixing, and fusion with irradiated chick erythrocyte ghosts suggested that unirradiated chromosomes in heterokaryons are damaged by a stable, nondiffusible cytoplasmic component contributed by the irradiated cell.

  7. 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

  8. Sister chromatid exchange (SCE) induced by laser-UV-microirradiation: correlation between the distribution of photolesions and the distribution of SCEs.

    PubMed

    Raith, M; Cremer, T; Cremer, C; Speit, G

    1984-01-01

    Small, medium, and large nuclear areas comprising approximately 5, 30, or 80% of the total area of the interphase nuclei of Chinese hamster cells (M3-1) cultivated in vitro were irradiated with a laser-UV-microbeam of wavelength 257 nm. The DNA of the cells was substituted with 5-bromodeoxyuridine (BrdUrd) for 1 cell cycle in one set of experiments. After microirradiation the cells were grown for a second cycle in medium without BrdUrd (protocol A). In a second set, cells with nonsubstituted DNA were microirradiated and grown for 2 additional cycles, the first in the presence, the second in the absence of BrdUrd (protocol B). In situ chromosome preparation and differential chromatid staining was subsequently performed. The induction of sister chromatid exchanges (SCEs) was found to be dependent on both the ultraviolet (UV) dose and the spatial distribution of the UV energy within the cell nucleus. Following both protocols the average number of chromosomes with SCEs was significantly higher after microirradiation of a large nuclear area as compared to microirradiation of a small nuclear area. In the latter case, multiple SCEs were noted on individual chromosome arms at the first postirradiation mitosis (protocol A). In other cells, especially at higher doses, protocol A resulted in shattering of a few closely neighbored chromosomes which were surrounded by intact ones with normal SCE levels. Microirradiation of medium-sized nuclear areas produced high levels of SCEs over a number of chromosomes which still appeared spatially related in a part of the metaphase spread. Finally, high SCE levels could be observed over most or all chromosomes when a large nuclear area (up to 100%) was exposed to the microbeam. Following protocol B the increase of SCEs was much less pronounced. Microirradiation of a small part of the cytoplasm in addition to the nuclei did not induce SCEs. Our results support the concept (i) that interphase chromosomes occupy distinct nuclear domains and

  9. 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

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

    PubMed

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

    2015-01-01

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

  11. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  12. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  13. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... references should be consulted. (1) 40 CFR 798.5915, In vivo Sister Chromatid Exchange Assay. (2) Kato, H...) 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...

  14. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  15. Nonhomologous chromatid exchange in hereditary and sporadic renal cell carcinomas.

    PubMed Central

    Kovacs, G; Kung, H F

    1991-01-01

    For the development of renal cell carcinomas, it has been suggested that a germ-line or somatic mutation occurs on one of the homologous chromosomes 3p, and subsequently the other 3p segment is lost. We have examined the karyotype and/or the allelic combination on chromosomes 3 and 5 by restriction fragment length polymorphism analysis in normal kidney and tumor samples from 28 renal cell carcinomas that developed in two patients with von Hippel-Lindau disease; we then compared the results to those of sporadic tumors. An unbalanced translocation between chromosome 3p and 5q or other chromosomes was found to be the most common aberration. We developed a model of nonhomologous chromatid exchange involving breakpoint clusters at chromosomes 3p13, 3p11.2, 5q22, and 8q11.2. Subsequent chromatid segregation may result in net loss of the 3p segment either (i) in one step or (ii) after a nondisjunctional loss of the derivative chromosome carrying the 3p segment. This general mechanism could also be implicated to explain genetic changes occurring in other types of solid tumors. Images PMID:1986366

  16. Increased sister chromatid exchange associated with smoking and coffee consumption.

    PubMed

    Reidy, J A; Annest, J L; Chen, A T; Welty, T K

    1988-01-01

    Sister chromatid exchange (SCE) is a very sensitive cytogenetic assay for detecting exposure to chemical mutagens and carcinogens. One application of SCE is the monitoring of populations believed to be exposed to such agents. We have, however, relatively little knowledge about common lifestyle factors that may influence SCE and therefore complicate any study designed to examine the effects of exposure to genotoxins. In this study, we assessed the effect of cigarette smoking and coffee consumption on SCE. Smoking was associated with an increase of approximately 2 SCEs per cell and a decrease in cell proliferation. A positive linear relationship between SCE and coffee consumption was also observed. This effect was similar for smokers and nonsmokers. Additionally, the folic acid content of cell culture medium seemed to affect neither SCE nor cell proliferation. PMID:3169009

  17. Sister chromatid exchanges in peripheral lymphocytes after preoperative mammography

    SciTech Connect

    Husum, B.; Wulf, H.C.; Niebuhr, E.

    1981-09-01

    Examination of sister chromatid exchanges (SCE) in peripheral lymphocytes may be useful for evaluating in vivo exposure to chemical mutagens. In vitro exposure of human lymphocytes to low levels of ionizing radiation has failed to produce increased SCE rates. Scarcity of information about the SCE test system and in vivo exposure to radiation prompted the present study of SCE rates in peripheral lymphocytes in women investigated with mammography prior to operation because of a tumor of the breast. In 64 of a total of 131 women a mammography was performed before the operation. The two groups of patients were identical with respect to age, smoking habits, and incidence of malignancy of the mammary tumors. SCE rates were examined in 30 metaphases from each patient following cultivation of peripheral blood lymphocytes using the BrdU/Giemsa technique.

  18. Telomere sister chromatid exchange in telomerase deficient murine cells

    SciTech Connect

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

    2005-01-01

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

  19. Cultured mouse embryos metabolize benzo[a]pyrene during early gestation: genetic differences detectable by sister chromatid exchange.

    PubMed Central

    Galloway, S M; Perry, P E; Meneses, J; Nebert, D W; Pedersen, R A

    1980-01-01

    Mouse embryos explanted at 7 1/2 or 8 1/2 days of gestation were cultured in medium containing benzo[a]pyrene and supplemented with 5-bromodeoxyuridine to allow detection of sister chromatid exchanges. The murine Ah locus regulates the inducible metabolism of polycyclic hydrocarbons such as benzo[a]pyrene. A high frequency of sister chromatid exchange was induced by benzo[a]pyrene in embryos from three Ah-"responsive" inbred strains (BALB/cDub, C3H/AnfCum, and C57BL/6N); there was little or no increase in two Ah-"nonresponsive" inbred strains (AKR/J and DBA/2J). Benzo[a]pyrene also induced sister chromatid exchanges in the Ah-responsive recombinant inbred line B6NXAKN-12 but not in the Ah-nonresponsive recombinant inbred line B6NXAKN-3. Sister chromatid exchange in cultured Ah-responsive mouse embryos was thus shown to be a sensitive assay. These data provide direct evidence that genetically responsive mouse embryos (early postimplantation stage) possess the subcellular processes necessary for induction of enzymes that metabolize benzo[a]pyrene to its chemically active forms(s). Both the Ah regulatory gene product (a cytoslic receptor) and the structural gene product (inducible cytochrome P1-450) therefore appear to be functional at an early embryonic age. Furthermore, this metabolic capacity may play an important role in the damage to embryonic cells by polycyclic hydracarbons. PMID:6932035

  20. Sister chromatid exchange assay as a predictor of tumor chemoresponse.

    PubMed

    Mourelatos, D

    2016-06-01

    Sister Chromatid Exchanges (SCEs) are known to enhance as a consequence of exposure to various mutagenic agents and appear to indicate DNA damaging effects and/or subsequent repair by homologous recombination (HR). DNA damage plays an interesting role in the majority of mechanisms underlying the effects of antitumor drugs, since the genetic activity of the plethora of these agents is due to their ability to damage the DNA. The DNA-effects of antitumor agents towards normal cells (genotoxicity) are great drawbacks of antitumor therapy and are connected to important adverse health effects in cancer patients undergoing chemotherapy. On the other hand, failure of chemotherapy in many cases is due to the DNA repair ability which cancer, like normal cells, also possess. As both DNA repair and genotoxic exposure are expected to vary among patients, correlating SCEs frequencies with only individual repair capacity may be feasible to predict. Cancer risk has not been observed to be associated with high SCEs levels. Since the administration of effective antitumor drugs with limited adverse effects is of great importance in the success of anticancer therapy, a lot of interest has been directed toward the development of methods and approaches that would enable the correct selection of appropriate drugs prior to the initiation of therapy on an individual basis. To this effect, more than 30 years ago, an investigation of the ability of the in vitro and the in vivo SCEs-assay to predict the in vitro and in vivo sensitivity of tumor cells to newly synthesized drugs or to those already in use began. In this short review a critical appraisal of the SCEs-assay as an important biomarker used for predicting cancer chemo-response as well as a summary of the key findings from several studies published within the last 20 years in this field is performed. PMID:27265374

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

    PubMed

    van Wietmarschen, Niek; Lansdorp, Peter M

    2016-08-19

    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

  2. Effect of lead chromate on chromosome aberration, sister-chromatid exchange and DNA damage in mammalian cells in vitro.

    PubMed

    Douglas, G R; Bell, R D; Grant, C E; Wytsma, J M; Bora, K C

    1980-02-01

    Possible mutagenic activity of lead chromate in mammalian cells was studied using assays for chromosome aberrations and sister-chromatid exchanges in cultured human lymphocytes, and DNA fragmentation as detected by alkaline-sucrose gradient sedimentation in cultured Chinese hamster ovary (CHO) cells. Lead chromate caused dose-related increases in chromosome aberration and sister-chromatid exchange in human lymphocytes. No increase in DNA damage was observed in CHO cells, possibly due to the relative insensitivity of the CHO cells and the limited solubility of lead chromate in tissue culture medium. The mutagenicity of lead chromate in human lymphocytes appears to be entirely due to the chromate ion since chromosome aberrations were induced by potassium chromate but not lead chloride. PMID:7374664

  3. 40 CFR 79.65 - In vivo sister chromatid exchange assay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... references should be consulted. (1) 40 CFR 798.5915, In vivo Sister Chromatid Exchange Assay. (2) Kato, H... peripheral blood lymphocytes, often from rodent species. (b) Definitions. For the purposes of this section... the end of the exposure period and blood lymphocyte cell cultures are prepared from study...

  4. EVIDENCE FOR THE CHROMOSOMAL REPLICONS AS UNITS OF SISTER CHROMATID EXCHANGES

    EPA Science Inventory

    Current hypotheses of sister chromatid exchange (SCE) formation postulate that sites of SCE induction are associated with active replicons or replicon clusters. We have applied the FCC-SCD technique to in vivo studies of mouse bone marrow cells that have been treated with cycloph...

  5. Chromosome aberration and sister chromatid exchange test results with 42 chemicals.

    PubMed

    Anderson, B E; Zeiger, E; Shelby, M D; Resnick, M A; Gulati, D K; Ivett, J L; Loveday, K S

    1990-01-01

    Forty-two chemicals were tested for their ability to induce cytogenetic change in Chinese hamster ovary cells using assays for chromosome aberrations (ABS) and sister chromatid exchanges (SCE). These chemicals were included in the National Toxicology Program's evaluation of the ability of four in vitro short-term genetic toxicity assays to distinguish between rodent carcinogens and noncarcinogens. The conclusions of this comparison are presented in Zeiger et al. [Zeiger E, Haseman JK, Shelby MD, Margolin BH, Tennant RW (1990): [Environ Molec Mutagen 16(Suppl 18): 1-14]. The in vitro cytogenetic testing was conducted at four laboratories, each using a standard protocol to evaluate coded chemicals with and without exogenous metabolic activation. Most chemicals were tested in a single laboratory; however, two chemicals, tribromomethane and p-chloroaniline, were tested at two laboratories as part of an interlaboratory comparison. Four chemicals (C.I. basic red 9 HCl, 2-mercaptobenzothiazole, oxytetracycline HCl, and rotenone) were tested for SCE in one laboratory and in a different laboratory for ABS. Tetrakis(hydroxymethyl)phosphonium sulfate was tested at one laboratory and the chloride form was tested at a different laboratory. Twenty-five of the 42 chemicals tested induced SCE. Sixteen of these also induced ABS; all chemicals that induced ABS also induced SCE. There was approximately 79% reproducibility of results in repeat tests, thus, we conclude that this protocol is effective and reproducible in detecting ABS and SCE. PMID:2091924

  6. 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.

  7. DNA crosslinking, sister-chromatid exchange and specific-locus mutations.

    PubMed

    Carrano, A V; Thompson, L H; Stetka, D G; Minkler, J L; Mazrimas, J A; Fong, S

    1979-11-01

    Chinese hamster ovary cells were treated with the DNA-crosslinking chemicals, mitomycin C (MMC) and porfiromycin (POR), and their monofunctional derivative decarbamoyl mitomycin C (DCMMC). After exposure, the cells were studied for the induction of sister-chromatid exchanges (SCEs) and mutations at the hypoxanthine phosphoribosyltransferase and adenine phosphoribosyltransferase loci. The frequency of SCEs varied significantly in successive sampling intervals, requiring the weighting of each interval by the percentage of second-division mitosis in that interval to obtain the mean SCE frequency for each dose. All 3 compounds were potent inducers of SCEs but weakly mutagenic. All 3 chemicals by concentration were approximately equally effective in inducing SCEs or mutations. When the induced SCEs and mutations were compared at equal levels of survival, DCMMC was slightly more effective than MMC or POR in inducing SCEs and somewhat less mutagenic. These results indicate that the DNA interstrand crosslink is not the major lesion responsible for the induction of SCE or mutation by these compounds. PMID:522865

  8. 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.

  9. INDUCTION, ACCUMULATION, AND PERSISTENCE OF SISTER CHROMATID EXCHANGES IN WOMEN WITH BREAST CANCER RECEIVING CYCLOPHOSPHAMIDE, ANDRIAMYCIN, AND 5-FLUOROACIL CHEMOTHERAPY

    EPA Science Inventory

    The induction, stimulation, and persistence of sister chromatid exchanges (SCE's) and high SCE frequency cells (HFC's) was measured in peripheral lymphocytes of women with breast cancer before chemotherapy and on multiple occasions during and after therapy. Chemotherapy consisted...

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

    PubMed

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

    2005-12-30

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

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

    SciTech Connect

    Not Available

    1993-03-01

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

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

    PubMed

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

    2014-11-01

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

  13. The effects of boric acid on sister chromatid exchanges and chromosome aberrations in cultured human lymphocytes

    PubMed Central

    Arslan, Mehmet; Topaktas, Mehmet

    2007-01-01

    The aim of this study was to determine the possible genotoxic effects of boric acid (BA) (E284), which is used as an antimicrobial agent in food, by using sister chromatid exchange (SCEs) and chromosome aberration (CAs) tests in human peripheral lymphocytes. The human lymphocytes were treated with 400, 600, 800, and 1000 μg/mL concentrations of BA dissolved in dimethyl sulfoxide (DMSO), for 24 h and 48 h treatment periods. BA did not increase the SCEs for all the concentrations and treatment periods when compared to control and solvent control (DMSO). BA induced structural and total CAs at all the tested concentrations for 24 and 48 h treatment periods. The induction of the total CAs was dose dependent for the 24 h treatment period. However, BA did not cause numerical CAs. BA showed a cytotoxic effect by decreasing the replication index (RI) and mitotic index (MI). BA decreased the MI in a dose-dependent manner for the 24 h treatment period. PMID:19002846

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

    PubMed Central

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

    1991-01-01

    Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. It was shown previously that asbestos samples collected from a local asbestos factory enhanced sister chromatid exchanges (SCEs) and chromosomal aberrations in vitro using human lymphocytes. In the present study, 22 workers from the same factory and 12 controls were further investigated. Controls were matched for age, sex, and socioeconomic state. The peripheral blood lymphocytes were cultured and harvested at 48 hours for studies of chromosomal aberrations and at 72 hours for SCE frequency determinations. Asbestos workers had a raised mean SCE rate and increased numbers of chromosomal aberrations compared with a control population. Most of the chromosomal aberrations were chromatid gap and break types. PMID:1998603

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

    PubMed

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

    1991-02-01

    Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. It was shown previously that asbestos samples collected from a local asbestos factory enhanced sister chromatid exchanges (SCEs) and chromosomal aberrations in vitro using human lymphocytes. In the present study, 22 workers from the same factory and 12 controls were further investigated. Controls were matched for age, sex, and socioeconomic state. The peripheral blood lymphocytes were cultured and harvested at 48 hours for studies of chromosomal aberrations and at 72 hours for SCE frequency determinations. Asbestos workers had a raised mean SCE rate and increased numbers of chromosomal aberrations compared with a control population. Most of the chromosomal aberrations were chromatid gap and break types. PMID:1998603

  16. Genotoxicity evaluation in patients on phenobarbital monotherapy by sister chromatid exchange.

    PubMed

    Schaumann, B A; Winge, V B; Pederson, M

    1989-01-01

    The potential of phenobarbital to interact with DNA has been studied using the sister chromatid exchange (SCE) assay in peripheral lymphocytes of nine adult male patients with epilepsy and of their matched controls. All patients were otherwise healthy individuals, treated chronically with phenobarbital in monotherapy. No statistically significant differences in SCE levels were found between the patient and control groups. Smoking was associated with increased SCE frequencies. The experiment was repeated with five available patients, using a slightly modified methodology. Although different SCE scores were obtained, the results of both tests were comparable. PMID:2585535

  17. 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)

  18. Sister chromatid exchange analysis in lymphocytes of workers exposed to hexavalent chromium.

    PubMed Central

    Nagaya, T; Ishikawa, N; Hata, H

    1989-01-01

    To investigate the usefulness of sister chromatid exchange (SCE) analysis in lymphocytes as an indicator for mutagenic effects after in vivo exposure to hexavalent chromium (Cr), SCE frequency was analysed in lymphocytes of 44 Cr platers occupationally exposed to hexavalent Cr and 47 controls. Although urinary Cr analysis confirmed that the Cr platers were exposed to Cr, no effects of the exposure on SCE frequency were found. Smokers, both Cr platers and controls, had a significantly higher SCE frequency than non-smokers. These results suggest that SCE analysis in human lymphocytes is not a good indicator of possible mutagenic effects of exposure to hexavalent Cr. PMID:2920143

  19. Comparison of sister chromatid exchange induction in murine germinal and somatic cells by gamma radiation exposure in vivo

    SciTech Connect

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

    1994-12-31

    Sister chromatid exchange (SCE) induction by gamma rays was determined in speratogonia irradiated before or after BrdU incorporation. Furthermore, the comparison of responses obtained in spermatogonia, bone marrow and salivary gland cells was carried out in the cells irradiated after BrdU incorporation, a condition which permits a higher SCE induction. Results indicate that gamma ray exposure of spermatogonia could induce a significant increase in SCE frequency with doses as low as 0.27 Gy, either before or after BrdU incorporation. However, the increase caused by radiation exposure after BrdU incorporation in spermatogonia was nearly three times lower than that obtained in both bone marrow and salivary gland cells. These data suggest that spermatogonia are either more efficient in repairing the gamma ray-induced lesions involved in SCE production or that these cells are less prone to the induction of such lesions. 53 refs., 2 figs., 3 tabs.

  20. The induction of sister chromatid exchanges by environmental pollutants: relationship of SCE to other measures of genetic damage

    SciTech Connect

    Brooks, A.L.; Shimizu, R.W.; Li, A.P.; Benson, J.M.; Dutcher, J.S.

    1984-01-01

    Sister chromatid exchanges (SCEs), induced by environmental pollutants from fossil fuel use, were measured in 2 cell systems, Chinese hamster ovary (CHO) cells and Chinese hamster primary lung cell cultures. The frequency of SCEs induced in these cell systems was related to other measures of genetic damage, namely mutations in CHO cells at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) gene locus and in bacteria (Salmonella mutagenicity test TA-98), produced by the same pollutants. The pollutants were divided into 2 classes: those produced in oxidizing combustion environments--extracts of particles from light-duty diesel cars, spark-ignition cars, and an automotive tunnel; and those produced in reducing environments--extracts from coke oven mains and condensates from a low BTU coal gasifier obtained either before or after cleanup of the process stream. Sister chromatid exchanges were induced by all pollutants without the addition of a rat liver microsomal fraction (S-9 mix), whereas S-9 mix was required to induce a positive response in the CHO/HGPRT assay for all pollutants. The pollutants produced in a reducing environment required metabolic activation by S-9 mix to be mutagenic in the Salmonella mutation assay. The addition of S-9 mix to pollutants produced in an oxidizing environment reduced the response in the Salmonella test. The relative genotoxic potency for each pollutant was determined for all 3 endpoints. The slopes of dose-response curves for each pollutant were plotted for each assay to compare relative potency. When the bacterial mutagenicity test was compared to either mammalian cell assay, SCE or CHO/HGPRT, there was little correlation between relative potencies. However, the data indicated that the responses in the 2 mammalian cell assays, SCE and CHO/HGPRT, showed similar relative responses to the pollutants.

  1. Sister chromatid exchanges in Chinese hamster ovary cells exposed to high intensity pulsed ultrasound: inability to confirm previous positive results.

    PubMed

    Miller, M W; Azadniv, M; Pettit, S E; Church, C C; Carstensen, E L; Hoffman, D

    1989-01-01

    This study was undertaken in an attempt to determine a physical mechanism of action for a recently published report of a small but statistically significant increase in sister chromatid exchanges (SCEs) in Chinese hamster ovary cells exposed to high-intensity pulsed ultrasound. The "positive" report's protocol involved a sizeable chance of ultrasound beam impingement on the side wall of the cell exposure chamber. Ten experiments per regimen were conducted; the regimens included exposures of (a) chamber center, (b) chamber wall, (c) nine grid sites, 0.5 mm between sites, and (d) nine grid sites, 1.5 mm between sites. The last was an exact replication of the conditions previously reported to induce the small SCE effect. The results did not support the postulate of an increase in SCEs with the ultrasound exposures. PMID:2741252

  2. KINETICS OF IN VIVO SISTER CHROMATID EXCHANGE INDUCTION IN MOUSE BONE MARROW CELLS BY ALKYLATING AGENTS: CYCLOPHOSPHAMIDE

    EPA Science Inventory

    Administration of cyclophosphamide (5, 10, 20 and 25 mg/kg body weight) to male CD-1 mice 2 hours after subcutaneous implantation of a 5-bromo-2'-deoxyuridine (BrdU) pellet (55 mg) resulted in a dose-dependent increase in sister chromatid exchanges (SCE) in bone marrow cells. Tre...

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

    SciTech Connect

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

    2005-01-01

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

  4. Effects of infliximab on sister chromatid exchanges and chromosomal aberration in patients with rheumatoid arthritis.

    PubMed

    Atteritano, M; Mazzaferro, S; Mantuano, S; Bagnato, G L; Bagnato, G F

    2016-03-01

    The aim of this study was to evaluate in a 24-weeks the effect of anti-TNF-alpha, infliximab, on cytogenetic biomarkers in peripheral lymphocytes of patients with rheumatoid arthritis (RA). A total of 40 patients with RA met the criteria to be treated with methotrexate (15 mg/week) were evaluated. Twenty patients, randomly selected, were treated with infliximab in addition to methotrexate (group I), whereas the other 20 patients continued with only methotrexate treatment (group M). Twenty healthy volunteers matched for age, gender and smoking habits served as control group (group C). At baseline, sister chromatid exchange rate was 7.20 ± 2.21 in group I, 7.40 ± 1.60 in group M and 4.97 ± 1.32 in group C (P < 0.01 vs group I and M). After 24-weeks, sister chromatid exchange rate was 7.87 ± 2.54 in group I and 7.81 ± 1.95 in group M (P = ns). High frequency cells count was 4.9 % and 4.7 % in the groups I and M, respectively, at the end of the study (P = ns). The basal chromosomal aberration frequency was 4.90 % in group I and 5.20 % in groups M; after 24-weeks, this was 5.10 % in group I and 5.10 % in groups M (P = ns). Infliximab treatment, for 24 weeks, did not increase the cytogenetic biomarkers in patients with RA. Our data show that the use of infliximab has not a genotoxic effect in patients with RA. PMID:26012953

  5. Retinoid protection against x-ray-induced chromatid damage in human peripheral blood lymphocytes.

    PubMed Central

    Sanford, K K; Parshad, R; Price, F M; Tarone, R E; Kraemer, K H

    1992-01-01

    Oral administration of isotretinoin (13-cis retinoic acid) was shown previously (Kraemer, K. H., J. J. DiGiovanna, A. N. Moshell, R. E. Tarone, and G. L. Peck. 1988. N. Engl. J. Med. 318:1633-1637) to reduce the frequency of skin cancers in xeroderma pigmentosum (XP) patients. The mechanism of protection was unclear. In the present study, x-ray-induced chromatid damage in PHA-stimulated blood lymphocytes from five XP patients receiving isotretinoin was approximately half that in blood samples from the same patients before or subsequent to treatment. The x-ray-induced chromatid damage in blood lymphocytes from a normal control was reduced significantly by cocultivation with blood or plasma from an XP patient receiving isotretinoin or by addition of 10(-6) M isotretinoin to cultures 1 h before x-irradiation. A similar reduction in x-ray-induced chromatid damage was reported previously by adding to the culture medium, mannitol, a scavenger of the free hydroxyl radical, or catalase, which decomposes hydrogen peroxide; both of these products are generated during ionizing radiation. The present observations suggest that isotretinoin acts as a scavenger of such radiation products, thereby providing protection against x-ray-induced chromatid damage. PMID:1430230

  6. 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.

  7. The induction of sister chromatid exchanges by environmental pollutants: relationship of SCE to other measures of genetic damage.

    PubMed

    Brooks, A L; Shimizu, R W; Li, A P; Benson, J M; Dutcher, J S

    1984-01-01

    Sister chromatid exchanges (SCEs), induced by environmental pollutants from fossil fuel use, were measured in 2 cell systems, Chinese hamster ovary (CHO) cells and Chinese hamster primary lung cell cultures. The frequency of SCEs induced in these cell systems was related to other measures of genetic damage, namely mutations in CHO cells at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) gene locus and in bacteria (Salmonella mutagenicity test TA-98), produced by the same pollutants. The pollutants were divided into 2 classes: those produced in oxidizing combustion environments--extracts of particles from light-duty diesel cars, spark-ignition cars, and an automotive tunnel; and those produced in reducing environments--extracts from coke oven mains and condensates from a low BTU coal gasifier obtained either before or after cleanup of the process stream. Sister chromatid exchanges were induced by all pollutants without the addition of a rat liver microsomal fraction (S-9 mix), whereas S-9 mix was required to induce a positive response in the CHO/HGPRT assay for all pollutants. The pollutants produced in a reducing environment required metabolic activation by S-9 mix to be mutagenic in the Salmonella mutation assay. The addition of S-9 mix to pollutants produced in an oxidizing environment reduced the response in the Salmonella test. The relative genotoxic potency for each pollutant was determined for all 3 endpoints. The slopes of dose-response curves for each pollutant were plotted for each assay to compare relative potency. When the bacterial mutagenicity test was compared to either mammalian cell assay, SCE or CHO/HGPRT, there was little correlation between relative potencies. However, the data indicated that the responses in the 2 mammalian cell assays, SCE and CHO/HGPRT, showed similar relative responses to the pollutants. Differences in the requirement for S-9 mix seem to be related to both the chemical nature of the mixture and the endpoint

  8. Analysis of chromosome aberrations and sister chromatid exchanges in peripheral blood lymphocytes of newborns after vitamin K prophylaxis at birth.

    PubMed

    Cornelissen, M; Smeets, D; Merkx, G; De Abreu, R; Kollee, L; Monnens, L

    1991-12-01

    In many countries vitamin K prophylaxis at birth is recommended to prevent bleeding in infants due to vitamin K deficiency. Because the incidence of clinical vitamin K deficiency is very low, such a vitamin K administration should be completely safe. However, an increase in sister chromatid exchanges in lymphocytes of fetal sheep 24 h after injection of vitamin K1 has been reported. Therefore, a study concerning genotoxicity of vitamin K1 in man was conducted. Sister chromatid exchanges and chromosome aberrations were analyzed in peripheral blood lymphocytes of six newborns 24 h after intramuscular administration of 1 mg vitamin K1 and in six control neonates. The mean number of sister chromatid exchanges per metaphase in the vitamin K group was 8.88 +/- 1.22 as compared with 9.05 +/- 1.14 in the control group (NS). The mean number of chromosome aberrations per 100 mitoses was 3.00 +/- 2.61 in the vitamin K group and 2.50 +/- 1.87 in the control group (NS). Vitamin K1 plasma concentrations ranged from 115 to 1150 ng/mL (255 to 2555 x 10(-9) M) in the supplemented group, a 5000-fold rise as compared with the control group (p less than 0.01). We did not find any evidence for genetic toxicity due to the administration of 1 mg vitamin K1 intramuscularly to the newborn child. PMID:1805152

  9. Role of oxygen free radicals in the induction of sister chromatid exchanges by cigarette smoke

    SciTech Connect

    Lee, C.K.; Brown, B.G.; Rice, W.Y. Jr.; Doolittle, D.J. )

    1989-01-01

    Cigarette smoke has been reported to contain free radicals and free radical generators in both the gas and particulate phases. Studies in our laboratory have shown that both cigarette smoke condensate (CSC) and smoke bubbled through phosphate buffered saline solution (smoke-PBS) increased sister chromatid exchanges (SCE) in Chinese hamster ovary cells in a dose-dependent manner. Since oxygen free radicals have been shown to cause SCEs and other chromosomal damage, we investigated the role of these radicals in the induction of SCEs by CSC and smoke-PBS. Addition of the antioxidant enzymes catalase and superoxide dismutase or the oxygen-radical scavenger ascorbic acid failed to reduce the SCE frequency in the presence of either CSC or smoke-PBS. Additional studies indicated that the quantity of hydrogen peroxide produced in CSC or smoke-PBS is too small to account for the observed SCE induction. It appears, therefore, that SCE induction by CSC or smoke-PBS does not involve the participation of oxygen free radicals.

  10. 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.

  11. The correlation between the frequency of sister-chromatid exchange and human reproductive hormones.

    PubMed

    Joseph-Lerner, N; Fejgin, M; Ben-Nun, I; Legum, C; Amiel, A

    1993-08-01

    Different frequencies of sister-chromatid exchanges (SCEs) during various stages of the menstrual cycle have previously been observed. We tested the hypothesis that sex hormones, particularly steroids, influence the frequency of SCEs in women undergoing ovulation induction for in vitro fertilization treatment. These women undergo extreme hormonal changes and therefore serve as a good model for testing the rate of genetic damage due to these changes. As controls, we tested fertile women with regular menstrual cycles who received no hormonal treatment. Peripheral lymphocytes were obtained during different stages of the normal and treated cycles. We examined SCE frequency as related to the different hormones of the reproductive cycle at each of the stages. In general, an increased SCE frequency was observed around ovulation time in the controls, and around the time of human chorionic gonadotropin administration in the group undergoing ovulation induction. However, in the latter group, SCE frequency was significantly higher. SCE frequency was positively correlated with the level of testosterone and FSH in the ovulation induction group, and positively correlated with the estradiol level in both groups. PMID:7687025

  12. Effects of cigarette smoking and solvent exposure on sister chromatid exchange frequency in painters

    SciTech Connect

    Kelsey, K.T.; Wiencke, J.K.; Little, F.F.; Baker, E.L. Jr.; Little, J.B.

    1988-01-01

    A cross-sectional study of sister chromatid exchange frequency (SCE) in peripheral blood lymphocytes from 117 members of the International Brotherhood of Painters and Allied Tradesman was conducted in union locals in two major US cities. Chronic solvent exposure intensity and duration were estimated from interviewer-administered-questionnaire data. SCE for all of the workers in the study were scored by one reader. A second reader determined the SCE frequency from a random sample of 30 workers. Age, coffee and alcohol intake and chronic solvent exposure (both intensity and duration, estimated over the working lifetime and over the year prior to study for each worker) did not significantly elevate SCE. The effect of smoking on SCE frequency, assessed by analysis of variance controlling for other possible confounding factors, showed that smoking increased SCE frequency. The SCE frequency in the smoking, solvent-exposed (estimated as lifetime exposure) painters were 6.75 SCE/cell; in the non-smoking, solvent-exposed workers the SCE frequency was 5.73 SCE/cell. These observations are consistent with other work suggesting that chronic solvent exposure in the paint trade is not associated with an elevation in SCE in peripheral blood lymphocytes. However, further work is necessary to address adequately the question of the genotoxicity of acute solvent exposure in these workers.

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

    PubMed

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

    2007-01-01

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

  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. PMID:26970083

  15. Induction of sister chromatid exchanges by direct and indirect chemical agents in a human teratoma cell line

    SciTech Connect

    Murison, G. . Dept. of Biological Sciences)

    1989-01-01

    In the present work, we have extended the characterization of the P3 cell line, derived from a human epithelial teratocarcinoma, by studying the induction of sister chromatid exchanges (SCEs) by direct and indirect carcinogens. Several direct-acting carcinogens produce a dose-dependent increase in SCEs. Most notably, N-methyl-N{prime}-nitro-N-nitrosoguanidine and 7{beta}, 8{alpha}-dihydroxy-9 {alpha},10{alpha}-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene produce increases in SCEs at dosages comparable to those used to induce mutations at the hypoxanthine-guanine phosphoribosyl transferase locus. The indirect carcinogens elicit SCEs only when the P3 cells are cocultured with cells capable of metabolizing the indirect carcinogens to the active form. Human breast carcinoma (BJ-015) and rat hepatoma (RL12) cells are equally efficient in activating polycyclic aromatic hydrocarbons to the active form. This cell-mediated induction of SCEs is obtained when P3 cells are incubated with live, x-irradiated, or UV-irradiated BJ or RL cells. This P3 cell line is thus equally suitable to study the induction of mutations or the induction of SCEs with direct and indirect carcinogens. 35 refs., 3 tabs.

  16. Effects of cigarette smoking and solvent exposure on sister chromatid exchange frequency in painters.

    PubMed

    Kelsey, K T; Wiencke, J K; Little, F F; Baker, E L; Little, J B

    1988-01-01

    A cross-sectional study of sister chromatid exchange frequency (SCE) in peripheral blood lymphocytes from 117 members of the International Brotherhood of Painters and Allied Tradesman was conducted in union locals in two major U.S. cities. Chronic solvent exposure intensity and duration were estimated from interviewer-administered-questionnaire data. SCE for all of the workers in the study were scored by one reader. A second reader determined the SCE frequency from a random sample of 30 workers. No significant difference in SCE frequency was associated with reader or time of reading. Age, coffee and alcohol intake and chronic solvent exposure (both intensity and duration, estimated over the working lifetime and over the year prior to study for each worker) did not significantly elevate SCE. The effect of smoking on SCE frequency, assessed by analysis of variance controlling for other possible confounding factors, showed that smoking increased SCE frequency (P less than .0001). The SCE frequency in the smoking, solvent-exposed (estimated as lifetime exposure) painters was 6.75 SCE/cell; in the non-smoking, solvent-exposed workers the SCE frequency was 5.73 SCE/cell; the controls had SCE levels of 6.84 SCE/cell (smokers) and 5.90 SCE/cell (non-smokers), respectively. These observations are consistent with other work suggesting that chronic solvent exposure in the paint trade is not associated with an elevation in SCE in peripheral blood lymphocytes. However, further work is necessary to address adequately the question of the genotoxicity of acute solvent exposure in these workers. PMID:3356184

  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. Sister chromatid exchange: A possible approach to characterize familial breast cancer patients.

    PubMed

    De Pascalis, Ivana; Pilato, Brunella; Mazzotta, Annalisa; Dell'Endice, Teresa Stefania; Rubini, Vincenza; Simone, Giovanni; Paradiso, Angelo; Aiello, Vincenzo; Mangia, Anita

    2015-02-01

    Sister chromatid exchange (SCE) frequency is widely used as an indicator of spontaneous chromosome instability. We investigated SCE frequency in the peripheral blood lymphocytes of familial and sporadic breast cancer (BC) patients from the Apulian Caucasian Population. Eighty-one patients were enrolled: 22 with familial history and 59 sporadic patients. Eleven familial patients had an 'increased risk' of BRCA gene mutation (BRCAPro ≥ 10%) and were candidates for BRCA1 and BRCA2 mutation analysis. For these reasons, we stratified the 22 familial BC patients in two group: 'low-risk' (n=11) and 'high-risk' (n=11) patients for BRCA gene mutations. Two of these 11 'high-risk' patients (18%) had pathogenic mutations in the BRCA2 gene. The subjects were not cigarette smokers or alcohol or drug users, and had no genetic disorders or chronic diseases affecting the family. Our results showed a significant increase in SCE frequency in the familial (5.305 ± 1.088/metaphase) (P<0.0001) and the sporadic patients (3.943 ± 0.552) (P<0.0001) compared to the controls (3.197 ± 0.649). We found that the SCE frequency was always significantly higher in familial than in sporadic patients, regardless of their clinicopathological characteristics. Moreover, we observed that the frequency of SCE in BRCA2 mutation carrier patients was higher compared to patients without mutations in BRCA1/2 genes. These findings highlight an intrinsic genomic instability in familial patients, and we suggest that SCE frequency may be used as a biomarker to better characterize familial BC. PMID:25434423

  19. 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.

  20. Molecular cloning of the human XRCC1 gene, which corrects defective DNA strand break repair and sister chromatid exchange.

    PubMed Central

    Thompson, L H; Brookman, K W; Jones, N J; Allen, S A; Carrano, A V

    1990-01-01

    We describe the cloning and function of the human XRCC1 gene, which is the first mammalian gene isolated that affects cellular sensitivity to ionizing radiation. The CHO mutant EM9 has 10-fold-higher sensitivity to ethyl methanesulfonate, 1.8-fold-higher sensitivity to ionizing radiation, a reduced capacity to rejoin single-strand DNA breaks, and a 10-fold-elevated level of sister chromatid exchange compared with the CHO parental cells. The complementing human gene was cloned from a cosmid library of a tertiary transformant. Two cosmid clones produced transformants that showed approximately 100% correction of the repair defect in EM9 cells, as determined by the kinetics of strand break repair, cell survival, and the level of sister chromatid exchange. A nearly full-length clone obtained from the pcD2 human cDNA expression library gave approximately 80% correction of EM9, as determined by the level of sister chromatid exchange. Based on an analysis of the nucleotide sequence of the cDNA insert compared with that of the 5' end of the gene from a cosmid clone, the cDNA clone appeared to be missing approximately 100 bp of transcribed sequence, including 26 nucleotides of coding sequence. The cDNA probe detected a single transcript of approximately 2.2 kb in HeLa polyadenylated RNA by Northern (RNA) blot hybridization. From the open reading frame and the positions of likely start sites for transcription and translation, the size of the putative XRCC1 protein is 633 amino acids (69.5 kDa). The size of the XRCC1 gene is 33 kb, as determined by localizing the endpoints on a restriction endonuclease site map of one cosmid clone. The deduced amino acid sequence did not show significant homology with any protein in the protein sequence data bases examined. Images PMID:2247054

  1. In vitro and occupational induction of sister-chromatid exchanges in human lymphocytes with furfuryl alcohol and furfural.

    PubMed

    Gomez-Arroyo, S; Souza, V

    1985-06-01

    Sister-chromatid exchanges (SCEs) in human lymphocytes were studied using the FPG technique in order to determine the cytogenetic effect of furfural and furfuryl alcohol. The induction of SCEs was also investigated in workers occupationally exposed to these solvents that are commonly used in the manufacture of furoic resins. The results obtained from the in vitro treatments show that furfural increased the number of SCEs, while furfuryl alcohol did not. In exposed workers, neither of these solvents increased the spontaneous frequency of SCEs per metaphase. PMID:4000179

  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. PMID:6211614

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

    PubMed

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

    2016-09-01

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

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

    SciTech Connect

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

    1994-09-01

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

  5. Elevated frequency of sister chromatid exchanges in lymphocytes of victims of the Tokyo sarin disaster and in experiments exposing lymphocytes to by-products of sarin synthesis.

    PubMed

    Li, Q; Minami, M; Clement, J G; Boulet, C A

    1998-09-01

    More than 5000 passengers of Tokyo subway trains were injured with toxic chemicals including the nerve gas sarin. Most of the victims examined had marked miosis and decreased serum cholinesterase activity. To monitor the genetic aftereffects of sarin exposure, we measured sister chromatid exchanges (SCEs) of the victims using peripheral blood lymphocytes. The frequency of SCEs was significantly higher in the victims than in the control group. Analyzing results using samples of urine from the victims suggested that the victims were exposed to not only sarin per se, but by-products of sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP) and ethyl isopropyl methylphosphonate (EIMP). Thus, the in vitro SCE-inducing effect of DIMP, DEMP and EIMP was examined using human lymphocytes and we obtained positive results. PMID:9776566

  6. 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.

  7. Mutagenicity of inhalation anaesthetics studied by the sister chromatid exchange test in lymphocytes of patients and operating room personnel.

    PubMed

    Husum, B

    1987-06-01

    Retrospective studies have indicated that operating room personnel may have increased risks of spontaneous abortion, congenital malformations in offspring, and cancer (Cohen et al 1980, Buring et al 1985). Occupational exposure to waste anaesthetic gases may be responsible for these possible adverse health effects, but a cause-effect relationship has never been proved. Induction of changes in the DNA in the chromosomes leading to mutations may play a role in teratogenicity and carcinogenicity. Along with an increasing concern in society regarding occupational diseases and working and living environment in general, cytogenetic methods have been developed for rapid detection of potential mutagenicity in vitro of chemical agents. One such method is the SCE test, which is based on examination of sister chromatid exchanges (SCEs), i.e. exchanges of chromatid-segments between the two chromatids in a chromosome, during cell replication. SCEs are not mutations, but an increased frequency of SCE is a sensitive indicator of exposure to agents that are capable of producing damage to the DNA and thus possibly mutations. In vitro tests like the SCE test are very useful for evaluation of specific chemical agents, which may be added to the culture in known concentrations. In studies of possible hazards from chemical agents in the working or living environment, the exposure is often poorly defined. Also, biotransformation may be different in different species, and the duration and the level of the exposure may play a role. Examination of SCEs is, therefore, increasingly performed directly on human lymphocytes from peripheral blood. Thus, although the examination of SCEs is still performed in vitro, the exposure has taken place in vivo. Increased SCE levels are then regarded as a non-specific indicator that the donor has been exposed to potentially mutagenic agents in the environment. The author and his associates used the SCE test to investigate the possible mutagenicity of

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Absence of a synergistic effect between moderate-power radio-frequency electromagnetic radiation and adriamycin on cell-cycle progression and sister-chromatid exchange.

    PubMed

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

    1991-01-01

    In our laboratories we are conducting investigations of potential interactions between radio-frequency electromagnetic radiation (RFR) and chemicals that are toxic by different mechanisms to mammalian cells. The RFR is being tested at frequencies in the microwave range and at different power levels. We report here on the 1) ability of simultaneous RFR exposures to alter the distribution of cells in first and second mitoses from that after treatment by adriamycin alone, and 2) on the ability of simultaneous RFR exposure to alter the extent of sister chromatid exchanges (SCEs) induced by adriamycin alone. This chemical was selected because of its reported mechanism of action and because it is of interest in the treatment of cancer. In our studies, Chinese hamster ovary (CHO) cells were exposed for 2 h simultaneously to adriamycin and pulsed RFR at a frequency of 2,450 MHz and a specific absorption rate of 33.8 W/Kg. The maximal temperature (in the tissue-culture medium) was 39.7 +/- 0.2 degrees C. The experiments were controlled for chemical and RFR exposures, as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin, and the RFR did not change the number of SCEs that were induced by the adriamycin, which adriamycin is known to affect cells by damaging their membranes and DNA. PMID:1759979

  14. Comparison of 6-thioguanine-resistant mutation and sister chromatid exchanges in Chinese hamster V79 cells with forty chemical and physical agents

    SciTech Connect

    Nishi, Y.; Hasegawa, M.M.; Taketomi, M.; Ohkawa, Y.; Inui, N.

    1984-08-01

    The induction of sister chromatid exchanges (SCE) and mutation at the hypoxanthine-guanine phosphoribosyl transferase locus and toxicities of 40 different chemical and physical agents were examined on Chinese hamster V79 cells. These agents included mono-, di-, tri-, and polyfunctional alkylating agents, intercalators, gamma-rays, and UV light irradiation. Mutation was measured as resistance to 6-thioguanine and toxicity as loss of cell-plating efficiency. SCE were examined 29 hr after treatment. With the agents examined, a highly positive correlation existed between SCE-inducing and mutagenic potencies, when expressed as increase in the number per a unit dose over the control values. But the great difference of the ratios of mutagenic potencies versus SCE-inducing potencies among agents was observed, the maximal difference in the ratios being about 200-fold. The agents that showed the higher values of the ratio (agents producing more mutations than SCE) were bleomycin, cobalt-60 gamma-rays, all ethylating agents (N-ethyl-N-nitrosourea, N-ethyl-N'-nitro-N-nitrosoguanidine, ethyl methanesulfonate, and diethylsulfate), N-propyl-N-nitrosourea, N-butyl-N-nitrosourea, isopropyl methanesulfonate, intercalating acridine compounds (2-methoxy-6-chloro-9-(3-(ethyl-2-chloroethyl)aminopropylamino)-acridine X 2HCl and 2-methoxy-6-chloro-9-(3-(chloroethyl)-aminopropylamino)acridine 2HCl) and UV light at 254 nm.

  15. G2-phase chromatid break kinetics in irradiated DNA repair mutant hamster cell lines using calyculin-induced PCC and colcemid-block.

    PubMed

    Bryant, Peter E; Mozdarani, Hossein; Marr, Christie

    2008-11-17

    We have investigated the role of the major pathways of DNA double-strand break (DSB) rejoining in the formation and kinetics of disappearance of chromatid breaks following irradiation in the G2 phase of the cell-cycle. We studied the responses of Chinese hamster cell lines xrs5, UV41 and irs1 with mutations in DNA repair genes XRCC5, ERCC4/XPF and XRCC2, involved in the non-homologous end-joining (NHEJ), single-strand annealing (SSA) and homologous recombination (HR) pathways of DSB rejoining respectively. We have used calyculin-induced PCC to study the kinetics of chromatid breaks in xrs5 and UV41 and wild-type CHOK1 cell line. xrs5 showed an elevated frequency of both spontaneous and radiation-induced chromatid breaks. However, the rate of disappearance of chromatid breaks with time was similar in xrs5 to that in its parental CHO cell line. The results with xrs5 firstly confirm our previous findings using the traditional colcemid-block technique, and secondly they demonstrate the independence of chromatid break kinetics of the radiation-induced cell-cycle checkpoint delay. The lack of correspondence between chromatid break kinetics and the deficiency in DSB rejoining in xrs5 argues strongly for an indirect involvement of DSB in the formation of chromatid breaks. The UV41 strain also showed similar chromatid break frequencies and kinetics to CHOK1 suggesting that the SSA pathway is not involved in the rejoining of DSB in the G2 phase of the cell-cycle. We found it not possible to use calyculin-induced PCC in V79-4 and irs1 cell lines. However, using colcemid block we show an elevation in both spontaneous and radiation-induced chromatid break frequency, and a similar rate of disappearance of G2 chromatid breaks with time after irradiation to its wild-type parental V79 line. Thus, deficiencies in two of the major pathways of DSB rejoining (NHEJ and HR) lead to elevated frequencies of chromatid breaks, but do not significantly influence the kinetics of their

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

    SciTech Connect

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

    1987-01-01

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

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

    SciTech Connect

    Not Available

    1990-04-01

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

  18. 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

  19. 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.

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

    SciTech Connect

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

    1989-01-01

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

  1. Increased sister chromatid exchange frequency in young women with breast cancer and in their first-degree relatives.

    PubMed

    Cefle, Kivanc; Ucur, Ali; Guney, Nese; Ozturk, Sukru; Palanduz, Sukru; Tas, Faruk; Asoglu, Oktar; Bayrak, Aysegul; Muslumanoglu, Mahmut; Aydiner, Adnan

    2006-11-01

    The well-known increased risk of breast cancer (BC) in first-degree relatives of patients with BC has been related to shared genetic factors including defective DNA repair, with loss of genomic integrity. On the other hand, it can be hypothesized that early-onset breast cancer is also associated with overburden of heritable factors leading to increased DNA injury. In this respect, we analyzed sister chromatid exchange frequency (SCE) in 20 women with breast cancer (all < or =40 years old), in their first-degree female relatives, and in 20 age-matched healthy females without a personal or family history of cancer. SCE was significantly increased (P < 0.05) in patients (7.17 +/- 1.81 per metaphase) and in their first-degree relatives (6.44 +/- 0.98), compared with controls (5.85 +/- 0.72). There was no difference in SCE frequency between patients and their first-degree relatives. We suggest that the increased SCE in patients reflects a genomic instability that may be operative in carcinogenesis. Further, genomic instability is shared also by first-degree relatives, although none of them had a history of breast cancer at the time of the study. PMID:17074593

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

    PubMed

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

    2001-01-01

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

  3. Elevated frequency of sister chromatid exchanges of lymphocytes in sarin-exposed victims of the Tokyo sarin disaster 3 years after the event.

    PubMed

    Li, Qing; Hirata, Yukiyo; Kawada, Tomoyuki; Minami, Masayasu

    2004-09-01

    We previously reported that the frequency of sister chromatid exchanges (SCEs) among victims of the Tokyo subway sarin disaster was significantly higher than that of controls 2-3 months after the disaster. It has been reported that the victims were also exposed to the by-products generated during sarin synthesis, i.e., diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP) and N,N-diethylaniline (DEA) during the disaster and we previously found that DIMP, DEMP and DEA induced a significant SCE increase in human lymphocytes in vitro. To monitor the genetic aftereffects of the sarin exposure, SCEs of peripheral blood lymphocytes were measured in fire fighters and police officers involved in the disaster 3 years after the event. We found that the frequency of SCEs was still significantly higher in the exposed subjects than the controls, suggesting a risk of the genetic aftereffects of the sarin exposure. We further found a significant positive correlation between the frequency of SCEs and the inhibition of serum cholinesterase activity in the exposed subjects, suggesting that the elevated frequency of SCEs is related to the sarin exposure. On the other hand, there was no significant difference in natural killer activity between the exposed and the controls. PMID:15297034

  4. Correlations of blood lead with DNA-protein cross-links and sister chromatid exchanges in lead workers.

    PubMed

    Wu, Fang-Yang; Chang, Pao-Wen; Wu, Chin-Ching; Kuo, Hsien-Wen

    2002-03-01

    Levels of sister chromatid exchanges (SCEs), high-SCE frequency cells (HFCs), DNA-protein cross-links (DPCs), blood lead (BLL), and zinc protoporphyrin (ZPP) were measured in peripheral blood from three groups. The lead workers were divided into two groups: a high BLL group (> or =15 microg/dl) and a low BLL group (<15 microg/dl). The control subjects were selected from an area that had not been contaminated with lead and had normal BLL and ZPP levels. In addition, exposure to airborne lead was measured for 11 lead workers, and the time-weighted average was shown to range from 0.19 to 10.32 mg/m(3). The BLL levels of 9 of 11 workers were >15 microg/dl, of which, 3 exceeded current exposure limits (> or =40 microg/dl). The BLL levels of all 11 controls were < 15 microg/dl. The average SCE and DPC values for the workers were 6.1 SCEs/cell and 1.9%, which were significantly higher (P < 0.01, Wilcoxon's test) than the value of 5.2 SCEs/cell and 1.1% for the control subjects. Lead workers had significantly higher BLL and ZPP levels than did the controls. Statistically significant increases in DPCs, SCEs, and HFCs were observed for the high-BLL group compared with the control group. The results of this study suggest that DPCs, SCEs, and HFCs are reliable biomarkers for monitoring workers exposed to lead and clearly indicate health effects from occupational exposure to lead. PMID:11895879

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

    PubMed

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

    2016-01-15

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

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

    PubMed

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

    1998-12-01

    Vinyl chloride monomer (VCM) is a human carcinogen. However, the exact mechanism of carcinogenesis remains unclear. VCM may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferases (GSTs). Thus workers with inherited variant metabolic enzyme activities may have an altered risk of genotoxicity. This study was designed to investigate which risk factors might affect sister chromatid exchange (SCE) frequency in polyvinyl chloride (PVC) workers. Study subjects were 44 male workers from three PVC factories. Questionnaires were administered to obtain detailed histories of cigarette smoking, alcohol consumption, occupations, and medications. SCE frequency in peripheral lymphocytes was determined using a standardized method, and CYP2E1, GSTM1, GSTT1 and ALDH2 genotypes were identified by the polymerase chain reaction (PCR). Analysis revealed that smoking status and exposure to VCM were significantly associated with increased SCE frequency. The presence of ALDH2 1-2/2-2 genotypes was also significantly associated with an elevation of SCE frequency (9. 5 vs. 8.1, p<0.01). However, CYP2E1, GSTM1 or GSTT1 genotypes were not significantly associated with SCE frequency. When various genotypes were considered together, combination of CYP2E1 c1c2/c2c2 with ALDH2 1-2/2-2 showed an additive effect on SCE frequency. Similar results were also found for the combination of smoking with CYP2E1, or smoking with ALDH2. These results suggest that VCM workers with ALDH2 1-2/2-2 genotypes, who also smoke, may have increased risk of DNA damage. PMID:9838066

  7. 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.

  8. Stimulation of Sister Chromatid Exchanges and Mutation by Aflatoxin B1-DNA Adducts in Saccharomyces cerevisiae Requires MEC1 (ATR), RAD53, and DUN1

    PubMed Central

    Fasullo, Michael; Sun, Mingzeng; Egner, Patricia

    2008-01-01

    The hepatocarcinogen aflatoxin B1 (AFB1) is a potent recombinagen but weak mutagen in the yeast Saccharomyces cerevisiae. AFB1 exposure induces DNA damage-inducible genes, such as RAD51 and those encoding ribonucleotide reductase (RNR), through a MEC1 (ATR homolog)-dependent pathway. Previous studies have indicated that MEC1 is required for both AFB1-associated recombination and mutation, and suggested that AFB1-DNA adducts are common substrates for recombination and mutagenesis. However, little is known about the downstream effectors of MEC1 required for genotoxic events associated with AFB1 exposure. Here we show that AFB1 exposure increases frequencies of RAD51-dependent unequal sister chromatid exchange (SCE) and activates Rad53 (CHK2). We found that MEC1, RAD53, and DUN1 are required for both AFB1-associated mutation and SCE. Deletion of SML1, which encodes an inhibitor of RNR, did not suppress the DUN1-dependent requirement for AFB1-associated genetic events, indicating that higher dNTP levels could not suppress the dun1 phenotype. We identified AFB1-DNA adducts and show that approximately the same number of adducts are obtained in both wild type and rad53 mutants. Since DUN1 is not required for UV-associated mutation and recombination, these studies define a distinct role for DUN1 in AFB1-associated mutagenesis and recombination. We speculate that AFB1-associated DNA adducts stall DNA replication, a consequence of which can either be mutation or recombination. PMID:18228255

  9. Possible synergistic effect of mercury and smoking on sister-chromatid-exchange (SCE) rates in humans

    SciTech Connect

    Mottironi, V.D.; Harrison, B.; Pollara, B.; Gooding, R.; Banks, S.

    1986-03-01

    The authors previously reported that exposure to mercury did not appear to cause DNA damage as measured by SCE. They have expanded these studies and have further defined smokers and nonsmokers in the mercury exposed population. Cytogenetic analyses were performed in 29 mercury exposed workers and in 26 controls. The SCE technique was applied to monitor the possible mutagenic effects of elemental and inorganic mercury in somatic cells of exposed workers from two plants that use a mercury electrolytic process to generate caustic soda and copper foil. The mercury levels in blood samples from the exposed workers showed a range of 6.69 to 103.90 ng/ml, with a mean of 26.90 ng/ml. The mercury levels for the controls ranged from 1.52 to 6.08 ng/ml, with a mean of 3.87 ng/ml. Mean duration of exposure was 8 years, with a range of 0.90 to 34.80 years. Results showed a significant increase in the number of SCE in exposed workers with high mercury levels as compared to controls. When exposed workers and controls were subdivided into smokers and nonsmokers, a significant increase in the number of SCE in smoking workers with either low or high mercury levels in their blood were also shown. The data suggest a mutagenic effect induced by mercury, which is further enhanced by smoking. Thus, mercury and smoking may exert a synergistic effect in the induction of SCE.

  10. 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.)

  11. Analysis of chromosome damage by sister chromatid exchange (SCE) and redox homeostasis characterization on sheep flocks from Sardinian pasturelands.

    PubMed

    Genualdo, Viviana; Perucatti, Angela; Pauciullo, Alfredo; Iannuzzi, Alessandra; Incarnato, Domenico; Spagnuolo, Maria Stefania; Solinas, Nicolina; Bullitta, Simonetta; Iannuzzi, Leopoldo

    2015-09-15

    Over the last decades, an increase of pollutants of diverse origin (industrial, military, mining, etc.) was recorded in several areas of Sardinia Island. We report the results of a multidisciplinary and complementary study based on cytogenetic and physiological analyses. The data obtained show the effects of the environmental impact on six sheep flocks (Sardinian breed) grazing on natural pasturelands next to possible polluted areas and compared to three herds grazing in different areas far from those potentially contaminated and used as control. Sister chromatid exchange (SCE) test was used as cytogenetic test to analyze chromosomal damages and it was performed on peripheral blood samples collected from 129 adult sheep (age > 4 years) randomly selected from polluted (92 animals) and control (37 animals) areas. Two types of cell cultures were performed: without (normal cultures) and with the addition of 5-BrdU. SCE-mean values estimated over 35 cells counted for each animal were 8.65 ± 3.40, 8.10 ± 3.50, 8.05 ± 3.08, 7.42 ± 3.34, 9.28 ± 3.56 and 8.38 ± 3.29 in the exposed areas, whereas the average values were 7.86 ± 3.31 in the control group. Significant increases (P < 0.01) of SCEs were found in three investigated areas of Southern Sardinia. Furthermore, sheep of the same flocks were characterized for blood redox homeostasis in order to define the potential targets of oxidative damage and to identify biomarkers of the extent of animal exposure to environmental contaminants. The plasma levels of Asc, Toc and Ret were found to be significantly lower (P < 0.001) in exposed sheep (I, II, IV and V) than in the control group. TAC as well as GPx and SOD activities were higher in control than in the exposed groups (P < 0.001). Finally, plasma levels of N-Tyr, PC, and LPO were significantly lower (P < 0.001) in the control group than in the exposed groups. PMID:25984702

  12. Genotoxicity of the anticonvulsant drug phenytoin (PHT): a follow-up study of PHT-untreated epileptic patients. I. Sister chromatid exchange (SCE) analysis.

    PubMed

    Kaul, A; Goyle, S

    1999-01-01

    Phenytoin (PHT) is a widely prescribed antiepileptic drug. Its potential to interact with genetic material was investigated in a set of 30 epileptic patients (age 10-30 years) prior to and following the administration of PHT over a period of 9 months (grouped in a multiple of 3 months) and 40 control subjects in relation to age, sex, duration of drug therapy, and plasma concentration of PHT, using the sister chromatid exchange (SCE) frequency assay. Plasma levels of the phenytoin were measured by biochemical assay in epileptic patients before and after the PHT therapy. The peripheral blood lymphocytes were cultured and harvested at 72 h. The frequency of SCE was significantly higher (P < 0.001) in both age groups (10-20 and 21-30 years) for PHT-treated epileptics compared to PHT-untreated and control subjects. However, there were no considerable variations in SCE finding between the control and PHT-untreated patients. Between the two age groups, a significantly higher SCE frequency was observed in PHT-treated patients (P < 0.01) in the older age group (21-30 years). Mean SCE frequency did not differ between the male and female in the controls, PHT-untreated, or treated epileptics. Correlation between the plasma concentration of PHT and the incidence of SCE among 30 patients was insignificant. PHT monotherapy appears to have genotoxic effect as expressed by the induction of increased SCE rates in treated epileptics, while disease does not play any role in inducing genetic damage as shown by no difference in SCE frequencies between control subjects and PHT-untreated epileptic patients. PMID:10321411

  13. 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.

  14. Use of a Ring Chromosome and Pulsed-Field Gels to Study Interhomolog Recombination, Double-Strand DNA Breaks and Sister-Chromatid Exchange in Yeast

    PubMed Central

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

    1989-01-01

    We 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 III (Chr. III). Meiotic recombination between this ring chromosome and a linear homolog produces new molecules of sizes distinguishable on gels from either parental molecule. We 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, we present data on the timing of commitment to meiotic recombination scored genetically. We 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-sized circles originating in part from sister-chromatid exchange, which we find to be frequent during meiosis. PMID:2693206

  15. Sister chromatid exchanges, hyperdiploidy and chromosomal rearrangements studied in cells from melanoma-prone individuals belonging to families with the dysplastic nevus syndrome.

    PubMed

    Jaspers, N G; Roza-de Jongh, E J; Donselaar, I G; Van Velzen-Tillemans, J T; van Hemel, J O; Rümke, P; van der Kamp, A W

    1987-01-01

    Cytogenetic investigations were performed on 25 individuals belonging to six melanoma-prone families with multiple melanocytic lesions (the dysplastic nevus syndrome, DNS). Patients having DNS with or without a history of melanoma were compared with clinically normal relatives and unrelated normal controls. The results indicate normal frequencies of hyperdiploidy and spontaneous sister chromatid exchanges in the fibroblasts of all individuals studied. Karyotypic analyses were carried out on the members of one family. The patients with DNS had a normal constitutional karyotype. In lymphocytes or fibroblasts from five patients, however, increased frequencies of cells with random chromosomal rearrangements were observed. These abnormalities, mainly translocations and inversions, were not found in two of the patients' spouses and in six clinically normal relatives. In the fibroblast cultures considerable clonal selection of cytogenetically abnormal cells occurred. PMID:3791172

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

    PubMed

    Ellenton, J A; McPherson, M F

    1983-01-01

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

  17. 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.

  18. 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.

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

    PubMed Central

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

    2015-01-01

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

  20. 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.

  1. 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.

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

    PubMed Central

    Kotadia, Shaila; Montembault, Emilie; Sullivan, William

    2012-01-01

    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. PMID:23185030

  3. 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

  4. Analysis of chromosomal aberrations, sister-chromatid exchanges and micronuclei in peripheral lymphocytes of pharmacists before and after working with cytostatic drugs.

    PubMed

    Roth, S; Norppa, H; Järventaus, H; Kyyrönen, P; Ahonen, M; Lehtomäki, J; Sainio, H; Sorsa, M

    1994-12-01

    The frequencies of chromosome aberrations, SCEs and micronuclei (cytokinesis-block method) in blood lymphocytes were compared among six nonsmoking female pharmacists before and after 1 year of working with cytostatic drugs. All possible precautions were taken to avoid exposure to cytostatics, including proper protective clothing and a monitored, negative-pressured working environment with vertical laminar flow cabinet. As referents, an age-matched group of six nonsmoking female hospital workers not dealing with cytostatics was simultaneously sampled twice with the same time interval. The pharmacists showed a marginally higher mean frequency of SCEs/cell (6.3; P = 0.049) after the working period than 1 year earlier (5.8). On the other hand, the referents, with no obvious exposure, had a higher mean number of cells with chromatid-type aberrations, gaps excluded, in the second sampling (2.0%; P = 0.048) than in the first one (0.5%). In addition, a slight (P = 0.055) trend towards a higher frequency of micronucleated binucleate cells was observed in the second sampling for both the exposed and control subjects. As such findings suggest technical variation in the cytogenetic parameters, the small difference observed in SCEs for the pharmacists between the two samplings was probably not related to the cytostatics exposure. No statistically significant differences were observed for any of the cytogenetic parameters in comparisons between the pharmacists and the referents. The findings suggest that caution should be exercised in comparing results obtained from two different samplings in prospective cytogenetic studies. PMID:7527908

  5. 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.

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

    PubMed

    Matsuoka, Atsuko; Isama, Kazuo; Tsuchiya, Toshie

    2005-11-01

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

  7. COMPARISON OF SISTER-CHROMATID EXCHANGE IN MOUSE PERIPHERAL BLOOD LYMPHOCYTES EXPOSED IN VITRO AND IN VIVO TO PHOSPHORAMIDE MUSTARD AND 4-HYDROXYCLOPHOSPHAMIDE

    EPA Science Inventory

    The present study was designed to investigate the genotoxicity of 4-hydroxycyclophosphamide (4-OHCP) and phosphoramide mustard (PAM), both reactive metabolites of cyclophosphamide (CP), for possible differences in SCE-inducing activity in mouse T- and B-lymphocytes. ouse peripher...

  8. Genetic control of recombination partner preference in yeast meiosis. Isolation and characterization of mutants elevated for meiotic unequal sister-chromatid recombination.

    PubMed Central

    Thompson, D A; Stahl, F W

    1999-01-01

    Meiotic exchange occurs preferentially between homologous chromatids, in contrast to mitotic recombination, which occurs primarily between sister chromatids. To identify functions that direct meiotic recombination events to homologues, we screened for mutants exhibiting an increase in meiotic unequal sister-chromatid recombination (SCR). The msc (meiotic sister-chromatid recombination) mutants were quantified in spo13 meiosis with respect to meiotic unequal SCR frequency, disome segregation pattern, sporulation frequency, and spore viability. Analysis of the msc mutants according to these criteria defines three classes. Mutants with a class I phenotype identified new alleles of the meiosis-specific genes RED1 and MEK1, the DNA damage checkpoint genes RAD24 and MEC3, and a previously unknown gene, MSC6. The genes RED1, MEK1, RAD24, RAD17, and MEC1 are required for meiotic prophase arrest induced by a dmc1 mutation, which defines a meiotic recombination checkpoint. Meiotic unequal SCR was also elevated in a rad17 mutant. Our observation that meiotic unequal SCR is elevated in meiotic recombination checkpoint mutants suggests that, in addition to their proposed monitoring function, these checkpoint genes function to direct meiotic recombination events to homologues. The mutants in class II, including a dmc1 mutant, confer a dominant meiotic lethal phenotype in diploid SPO13 meiosis in our strain background, and they identify alleles of UBR1, INP52, BUD3, PET122, ELA1, and MSC1-MSC3. These results suggest that DMC1 functions to bias the repair of meiosis-specific double-strand breaks to homologues. We hypothesize that the genes identified by the class II mutants function in or are regulators of the DMC1-promoted interhomologue recombination pathway. Class III mutants may be elevated for rates of both SCR and homologue exchange. PMID:10511544

  9. 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.

  10. 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.

  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. Flow-induced vibration of component cooling water heat exchangers

    SciTech Connect

    Yeh, Y.S.; Chen, S.S. . Nuclear Engineering Dept.; Argonne National Lab., IL )

    1990-01-01

    This paper presents an evaluation of flow-induced vibration problems of component cooling water heat exchangers in one of Taipower's nuclear power stations. Specifically, it describes flow-induced vibration phenomena, tests to identify the excitation mechanisms, measurement of response characteristics, analyses to predict tube response and wear, various design alterations, and modifications of the original design. Several unique features associated with the heat exchangers are demonstrated, including energy-trapping modes, existence of tube-support-plate (TSP)-inactive modes, and fluidelastic instability of TSP-active and -inactive modes. On the basis of this evaluation, the difficulties and future research needs for the evaluation of heat exchangers are identified. 11 refs., 19 figs., 3 tabs.

  13. Commitment in Structurally Enabled and Induced Exchange Relations

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  14. CYCLOPENTA[CD]PYRENE-INDUCED TUMORIGENICITY, KI-RAS CODON 12 MUTATIONS AND DNA ADDUCTS IN STRAIN A/J MOUSE LUNG

    EPA Science Inventory

    Cyclopenta[cd]pyrene (CPP) is a ubiquitous cyclopenta-fused polycyclic aromatic hydrocarbon. PP is highly genotoxic in bacterial and mammalian systems inducing gene mutations, sister-chromatid exchanges, and morphological transformation. PP is a mouse skin carcinogen, a mouse ski...

  15. 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

  16. Chromatin Structure and Radiation-Induced Intrachromosome Exchange

    NASA Technical Reports Server (NTRS)

    Mangala; Zhang, Ye; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

    2011-01-01

    We have recently investigated the location of breaks involved in intrachromosomal type exchange events, using the multicolor banding in situ hybridization (mBAND) technique for human chromosome 3. In human epithelial cells exposed to both low- and high-LET radiations in vitro, intrachromosome exchanges were found to occur preferentially between a break in the 3p21 and one in the 3q11. Exchanges were also observed between a break in 3p21 and one in 3q26, but few exchanges were observed between breaks in 3q11 and 3q26, even though the two regions were on the same arm of the chromosome. To explore the relationships between intrachromosome exchanges and chromatin structure, we used probes that hybridize the three regions of 3p21, 3q11 and 3q26, and measured the distance between two of the three regions in interphase cells. We further analyzed fragile sites on the chromosome that have been identified in various types of cancers. Our results demonstrated that the distribution of breaks involved in radiation-induced intrachromosome aberrations depends upon both the location of fragile sites and the folding of chromatins

  17. 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

  18. SISTER CHROMATID EXCHANGE AND GENOTOXICITY MEASUREMENTS USING POLYCHAETE WORMS

    EPA Science Inventory

    Contaminants entering coastal marine environments may affect the genetic constitution of exposed organisms by causing shifts in gene pool composition through selective pressures or by acting directly on the genetic material to cause damage. he latter problem is referred to as gen...

  19. The nature of high frequency sister chromatid exchange cells (HFCs).

    PubMed

    Ponzanelli, I; Landi, S; Bernacchi, F; Barale, R

    1997-09-01

    We employed the three-way differential staining technique (TWD), which allows SCEs to be distinguished on a per generation basis by scoring third metaphases (M3), in order to study the spontaneous levels of SCEs in normal and high frequency cells (HFCs) that occurred in the first (S1), second (S2) and third (S3) S phases. Fifty one of 900 lymphocytes from 37 healthy donors were defined as HFCs by calculating the 95th percentile of the distribution of SCEs in S1 + S2. 'Normal' cells presented almost the same number of SCEs after the first, second and third cell cycles (SCE averages of 2.43, 2.04 and 3.53 respectively). In contrast, HFCs showed a higher SCE count in S1, which decreased rapidly through the cycles and reached baseline level at S3 (SCE averages of 7.18, 4.29 and 3.45 respectively). This would suggest that the lesions responsible for the higher SCE frequency in HFCs were effectively removed after two cell cycles and strongly support the hypothesis that HFCs are lymphocytes which accumulate higher levels of DNA lesions through time. PMID:9379910

  20. Proximity induced exchange interaction in graphene-YIG devices

    NASA Astrophysics Data System (ADS)

    Leutenantsmeyer, Johannes Christian; Kaverzin, Alexey; Wojtaszek, Magdalena; van Wees, Bart J.; Physics of Nanodevices Team

    The proximity of two materials with radically different properties can give rise to a new physical phenomenon present only in the direct vicinity to the interface. Graphene is a perfect candidate for observing proximity effects as being ultimately thin and therefore ultimately sensitive for such interactions. Ferromagnetism is one of the desired properties for spintronics applications of graphene. It is absent in the pristine state, however, one can artificially induce magnetic ordering by bringing graphene in the proximity of ferrimagnetic insulating material, such as yttrium iron garnet (YIG). In this work we show that a monolayer of graphene placed on top of YIG adopts the exchange interaction induced by YIG and thus becomes ferromagnetic even at room temperatures. The proximity induced exchange interaction results in an effective magnetic field that influences directly the spin transport in graphene seen in a spin precession measurements. We are able to fit the measured Hanle dependences with extended solutions of Bloch diffusion equations and extract the value of the effective exchange field that is around 200 mT. Our findings open up a new route for creating novel all graphene in plane spin valve devices for spintronics applications. European Union's Seventh Framework Programme n607904-13 Spinograph, n604391 Graphene Flagship, FOM, ZIAM.

  1. 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

  2. A Long Noncoding RNA Regulates Sister Chromatid Cohesion.

    PubMed

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

    2016-08-01

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

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

    PubMed Central

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

    1995-01-01

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

  4. Precocious Sister Chromatid Separation (PSCS) in Cornelia de Lange Syndrome

    PubMed Central

    Kaur, Maninder; DeScipio, Cheryl; McCallum, Jennifer; Yaeger, Dinah; Devoto, Marcella; Jackson, Laird G.; Spinner, Nancy B.; Krantz, Ian D.

    2009-01-01

    The Cornelia de Lange syndrome (CdLS) (OMIM# 122470) is a dominantly inherited multisystem developmental disorder. The phenotype consists of characteristic facial features, hirsutism, abnormalities of the upper extremities ranging from subtle changes in the phalanges and metacarpal bones to oligodactyly and phocomelia, gastroesophageal dysfunction, growth retardation, and neurodevelopmental delay. Prevalence is estimated to be as high as 1 in 10,000. Recently, mutations in NIPBL were identified in sporadic and familial CdLS cases. To date, mutations in this gene have been identified in over 45% of individuals with CdLS. NIPBL is the human homolog of the Drosophila Nipped-B gene. Although its function in mammalian systems has not yet been elucidated, sequence homologs of Nipped-B in yeast (Scc2 and Mis4) are required for sister chromatid cohesion during mitosis, and a similar role was recently demonstrated for Nipped-B in Drosophila. In order to evaluate NIPBL role in sister chromatid cohesion in humans, metaphase spreads on 90 probands (40 NIPBL mutation positive and 50 NIPBL mutation negative) with CdLS were evaluated for evidence of precocious sister chromatid separation (PSCS). We screened 50 metaphases from each proband and found evidence of PSCS in 41% (compared to 9% in control samples). These studies indicate that NIPBL may play a role in sister chromatid cohesion in humans as has been reported for its homologs in Drosophila and yeast. PMID:16100726

  5. DNA damage tolerance branches out toward sister chromatid cohesion

    PubMed Central

    Branzei, Dana

    2016-01-01

    ABSTRACT Genome duplication is temporarily coordinated with sister chromatid cohesion and DNA damage tolerance. Recently, we found that replication fork-coupled repriming is important for both optimal cohesion and error-free replication by recombination. The mechanism involved has implications for the etiology of replication-based genetic diseases and cancer. PMID:27308553

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

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  7. 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.

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

    PubMed

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

    2008-09-15

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

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

    PubMed Central

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

    2016-01-01

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

  10. Sister chromatid junctions in the hyperthermophilic archaeon Sulfolobus solfataricus

    PubMed Central

    Robinson, Nicholas P; Blood, Katherine A; McCallum, Simon A; Edwards, Paul A W; Bell, Stephen D

    2007-01-01

    Although the Archaea exhibit an intriguing combination of bacterial- and eukaryotic-like features, it is not known how these prokaryotic cells segregate their chromosomes before the process of cell division. In the course of our analysis of the third replication origin in the archaeon Sulfolobus solfataricus, we identify and characterise sister chromatid junctions in this prokaryote. This pairing appears to be mediated by hemicatenane-like structures, and we provide evidence that these junctions persist in both replicating and postreplicative cells. These data, in conjunction with fluorescent in situ hybridisation analyses, suggest that Sulfolobus chromosomes have a significant period of postreplicative sister chromatid synapsis, a situation that is more reminiscent of eukaryotic than bacterial chromosome segregation mechanisms. PMID:17255945

  11. 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.

  12. Merotelic attachments allow alignment and stabilization of chromatids in meiosis II oocytes.

    PubMed

    Kouznetsova, Anna; Hernández-Hernández, Abrahan; Höög, Christer

    2014-01-01

    The chromosome segregation process in human oocytes is highly error-prone, generating meiosis II (MII) oocytes with unbalanced chromatids that contribute to aneuploidy in offspring. This raises questions regarding the mechanism for transmission of chromatids and how chromatids evade the error correction mechanisms in MII oocytes. Here, we analyse the behaviour of chromatids in mouse MII oocytes. We find that chromatids align at the spindle equator at the metaphase stage of MII and that their presence does not obstruct entry into the anaphase stage. The alignment process is mediated by merotelic (bi-directional) microtubule-kinetochore attachments, revealing a multi-domain organization of the kinetochore of mammalian meiotic chromosomes. Our results suggest that biorientation of chromatids stabilize microtubule attachments at the kinetochores in a tension-dependent manner. Our results also suggest that merotelic attachments contribute to chromosome mis-segregation in wild-type MII oocytes. Thus, merotely is an important promoter of aneuploidy in mammalian oocytes. PMID:25007239

  13. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-08-01

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

  16. 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. PMID:23430991

  17. Mechanics of Sister Chromatids studied with a Polymer Model English</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yang; Isbaner, Sebastian; Heermann, Dieter</p> <p>2013-10-01</p> <p>Sister <span class="hlt">chromatid</span> cohesion denotes the phenomenon that sister <span class="hlt">chromatids</span> are initially attached to each other in mitosis to guarantee the error-free distribution into the daughter cells. Cohesion is mediated by binding proteins and only resolved after mitotic chromosome condensation is completed. However, the amount of attachement points required to maintain sister <span class="hlt">chromatid</span> cohesion while still allowing proper chromosome condensation is not known yet. Additionally the impact of cohesion on the mechanical properties of chromosomes also poses an interesting problem. In this work we study the conformational and mechanical properties of sister <span class="hlt">chromatids</span> by means of computer simulations. We model both protein-mediated cohesion between sister <span class="hlt">chromatids</span> and chromosome condensation with a dynamic binding mechanisms. We show in a phase diagram that only specific link concentrations lead to connected and fully condensed <span class="hlt">chromatids</span> that do not intermingle with each other nor separate due to entropic forces. Furthermore we show that dynamic bonding between <span class="hlt">chromatids</span> decrease the Young's modulus compared to non-bonded <span class="hlt">chromatids</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780068435&hterms=solar+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bhydrogen','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780068435&hterms=solar+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bhydrogen"><span id="translatedtitle">The diurnal and solar cycle variation of the charge <span class="hlt">exchange</span> <span class="hlt">induced</span> hydrogen escape flux</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maher, L. J.; Tinsley, B. A.</p> <p>1978-01-01</p> <p>On the basis of ion temperature and density data at specific points and times in June 1969 provided by the OGO 6 satellite, and altitude profiles of the ion and electron temperature and concentration provided by the Arecibo radar facility over the period February 1972-April 1974, the diurnal and solar cycle variation of the charge-<span class="hlt">exchange-induced</span> hydrogen escape flux was investigated. It was calculated that for low to moderate solar activity at Arecibo, the diurnal ratio of the maximum-to-minimum charge-<span class="hlt">exchange-induced</span> hydrogen escape flux was approximately 6 with a peak around noon and a minimum somewhere between 0100 and 0300 h LT. This study of a limited amount of OGO 6 and Arecibo data seems to indicate that the charge-<span class="hlt">exchange-induced</span> hydrogen escape flux increases as the F(10.7) flux increases for low to moderate solar activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27084937','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27084937"><span id="translatedtitle">Transcription facilitates sister <span class="hlt">chromatid</span> cohesion on chromosomal arms.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bhardwaj, Shweta; Schlackow, Margarita; Rabajdova, Miroslava; Gullerova, Monika</p> <p>2016-08-19</p> <p>Cohesin is a multi-subunit protein complex essential for sister <span class="hlt">chromatid</span> cohesion, gene expression and DNA damage repair. Although structurally well studied, the underlying determinant of cohesion establishment on chromosomal arms remains enigmatic. Here, we show two populations of functionally distinct cohesin on chromosomal arms using a combination of genomics and single-locus specific DNA-FISH analysis. Chromatin bound cohesin at the loading sites co-localizes with Pds5 and Eso1 resulting in stable cohesion. In contrast, cohesin independent of its loader is unable to maintain cohesion and associates with chromatin in a dynamic manner. Cohesive sites coincide with highly expressed genes and transcription inhibition leads to destabilization of cohesin on chromatin. Furthermore, induction of transcription results in de novo recruitment of cohesive cohesin. Our data suggest that transcription facilitates cohesin loading onto chromosomal arms and is a key determinant of cohesive sites in fission yeast. PMID:27084937</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001RaPC...60..503C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001RaPC...60..503C"><span id="translatedtitle">Desalination by electrodialysis with the ion-<span class="hlt">exchange</span> membrane prepared by radiation-<span class="hlt">induced</span> graft polymerization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Seong-Ho; Han Jeong, Young; Jeong Ryoo, Jae; Lee, Kwang-Pill</p> <p>2001-01-01</p> <p>Ion-<span class="hlt">exchange</span> membranes modified with the triethylamine [-N(CH 2CH 3) 3] and phosphoric acid (-PO 3 H) groups were prepared by radiation-<span class="hlt">induced</span> grafting of glycidyl methacrylate (GMA) onto the polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly(GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-<span class="hlt">exchange</span> groups were investigated by SEM, XPS, TGA, and DSC. Furthermore, electrochemical properties such as specific electric resistance, transport number of K +, and desalination were examined. The grafting yield increased with increasing reaction time and reaction temperature. The maximum grafting yield was obtained with 40% (vol.%) monomer concentration in dioxane at 60°C. The content of the cation- and anion-<span class="hlt">exchange</span> group increased with increasing grafting yield. Electrical resistance of the PNF modified with TEA and -PO 3 H group decreased, while the water uptake (%) increased with increasing ion-<span class="hlt">exchange</span> group capacities. Transport number of the PNF modified with ion-<span class="hlt">exchange</span> group were the range of ca. 0.82-0.92. The graft-type ion-<span class="hlt">exchange</span> membranes prepared by radiation-<span class="hlt">induced</span> graft copolymerization were successfully applied as separators for electrodialysis.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55g0304O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55g0304O"><span id="translatedtitle"><span class="hlt">Exchange</span> bias controlled by electric current: Interplay of Joule heating and the <span class="hlt">induced</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oda, Kent; Moriyama, Takahiro; Kawaguchi, Masashi; Kamiya, Michinari; Tanaka, Kensho; Kim, Kab-Jin; Ono, Teruo</p> <p>2016-07-01</p> <p><span class="hlt">Exchange</span> bias is a unidirectional magnetic anisotropy developed in a bilayer of ferromagnetic and antiferromagnetic layers. Its technical importance as a “fix layer” is seen in various spintronic devices. The <span class="hlt">exchange</span> bias can also be a probe to investigate the antiferromagnetic layer as it partly reflects the magnetic state of the antiferromagnet. In this work, we investigated the modulation of the <span class="hlt">exchange</span> bias by a flow of electric current in Pt/Fe50Mn50/FeNi and Cu/Fe50Mn50/FeNi. We show that the <span class="hlt">exchange</span> bias can be modulated just by applying the current due to interplay among the Joule heating, Ampere field, and current-<span class="hlt">induced</span> effective field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EL....11437001N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EL....11437001N"><span id="translatedtitle"><span class="hlt">Exchange</span> bias-like effect in TbFeAl <span class="hlt">induced</span> by atomic disorder</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nair, Harikrishnan S.; Strydom, André M.</p> <p>2016-05-01</p> <p>The <span class="hlt">exchange</span> bias-like effect observed in the intermetallic compound TbFeAl, which displays a magnetic phase transition at T^hc ≈ 198 \\text{K} and a second one at T^lc ≈ 154 \\text{K} , is reported. Jump-like features are observed in the isothermal magnetization, M (H) , at 2 K which disappear above 8 K. The field-cooled magnetization isotherms below 10 K show loop shifts that are reminiscent of <span class="hlt">exchange</span> bias, also supported by the training effect. A significant coercive field, Hc ≈ 1.5 \\text{T} at 2 K, is observed in TbFeAl which, after an initial increase, shows a subsequent decrease with temperature. The <span class="hlt">exchange</span> bias field, H eb , shows a slight increase and a subsequent leveling off with temperature. It is argued that the inherent crystallographic disorder among Fe and Al and the high magnetocrystalline anisotropy related to Tb3+ lead to the <span class="hlt">exchange</span> bias effect. TbFeAl has been recently reported to show the magnetocaloric effect and the present discovery of <span class="hlt">exchange</span> bias makes this compound a multifunctional one. The result obtained on TbFeAl generalizes the observation of <span class="hlt">exchange</span> bias in crystallographically disordered materials and gives impetus for the search for materials with <span class="hlt">exchange</span> bias <span class="hlt">induced</span> by atomic disorder.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NaPho...9..506B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NaPho...9..506B"><span id="translatedtitle">Probing ultrafast photo-<span class="hlt">induced</span> dynamics of the <span class="hlt">exchange</span> energy in a Heisenberg antiferromagnet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Batignani, G.; Bossini, D.; di Palo, N.; Ferrante, C.; Pontecorvo, E.; Cerullo, G.; Kimel, A.; Scopigno, T.</p> <p>2015-08-01</p> <p>Manipulating the macroscopic phases of solids using ultrashort light pulses has resulted in spectacular phenomena, including metal-insulator transitions, superconductivity and subpicosecond modification of magnetic order. The development of this research area strongly depends on the understanding and optical control of fundamental interactions in condensed matter, in particular the <span class="hlt">exchange</span> interaction. However, disentangling the timescales relevant for the contributions of the <span class="hlt">exchange</span> interaction and spin dynamics to the <span class="hlt">exchange</span> energy, Eex, is a challenge. Here, we introduce femtosecond stimulated Raman scattering to unravel the ultrafast photo-<span class="hlt">induced</span> dynamics of magnetic excitations at the edge of the Brillouin zone. We find that femtosecond laser excitation of the antiferromagnet KNiF3 triggers a spectral shift of the two-magnon line, the energy of which is proportional to Eex. By unravelling the photo-<span class="hlt">induced</span> modification of the two-magnon line frequency from a dominating nonlinear optical effect, we find that Eex is increased by the electromagnetic stimulus.</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145703','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145703"><span id="translatedtitle">Acid-<span class="hlt">induced</span> <span class="hlt">exchange</span> of the imino proton in G.C pairs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nonin, S; Leroy, J L; Gueron, M</p> <p>1996-01-01</p> <p>Acid-<span class="hlt">induced</span> catalysis of imino proton <span class="hlt">exchange</span> in G.C pairs of DNA duplexes is surprisingly fast, being nearly as fast as for the isolated nucleoside, despite base-pair dissociation constants in the range of 10(-5) at neutral or basic pH. It is also observed in terminal G.C pairs of duplexes and in base pairs of drug-DNA complexes. We have measured imino proton <span class="hlt">exchange</span> in deoxyguanosine and in the duplex (ATATAGATCTATAT) as a function of pH. We show that acid-<span class="hlt">induced</span> <span class="hlt">exchange</span> can be assigned to proton transfer from N7-protonated guanosine to cytidine in the open state of the pair. This is faster than transfer from neutral guanosine (the process of intrinsic catalysis previously characterized at neutral ph) due to the lower imino proton pK of the protonated form, 7.2 instead of 9.4. Other interpretations are excluded by a study of <span class="hlt">exchange</span> catalysis by formiate and cytidine as <span class="hlt">exchange</span> catalysts. The cross-over pH between the regimes of pH-independent and acid-<span class="hlt">induced</span> <span class="hlt">exchange</span> rates is more basic in the case of base pairs than in the mononucleoside, suggestive of an increase by one to two decades in the dissociation constant of the base pair upon N7 protonation of G. Acid-<span class="hlt">induced</span> catalysis is much weaker in A.T base pairs, as expected in view of the low pK for protonation of thymidine. PMID:8604298</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145417','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=145417"><span id="translatedtitle">Securin degradation is mediated by fzy and fzr, and is required for complete <span class="hlt">chromatid</span> separation but not for cytokinesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zur, Amit; Brandeis, Michael</p> <p>2001-01-01</p> <p>We have studied the ubiquitination and degradation patterns of the human securin/PTTG protein. We show that, in contrast to budding yeast pds1, securin degradation is catalyzed by both fzy (fizzy/cdc20) and fzr (fizzy-related/cdh1/hct1). Both fzy and fzr also <span class="hlt">induce</span> the APC/C to ubiquitinate securin in vitro. Securin degradation is mediated by an RXXL destruction box and a KEN box, and is inhibited only when both sequences are mutated. Interestingly, the non-degradable securin mutant is also partially ubiquitinated by fzy and fzr in vitro. Expressing the non-degradable securin mutant in cells frequently resulted in incomplete <span class="hlt">chromatid</span> separation and gave rise to daughter cells connected by a thin chromatin fiber, presumably of chromosomes that failed to split completely. Strikingly, the mutant securin did not prevent the majority of sister <span class="hlt">chromatids</span> from separating completely, nor did it prevent mitotic cyclin degradation and cytokinesis. This phenotype, reminiscent of the fission yeast cut (cells untimely torn) phenotype, is reported here for the first time in mammals. PMID:11179223</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27136266','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27136266"><span id="translatedtitle">Sister <span class="hlt">chromatid</span> resolution is an intrinsic part of chromosome organization in prophase.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nagasaka, Kota; Hossain, M Julius; Roberti, M Julia; Ellenberg, Jan; Hirota, Toru</p> <p>2016-06-01</p> <p>The formation of mitotic chromosomes requires both compaction of chromatin and the resolution of replicated sister <span class="hlt">chromatids</span>. Compaction occurs during mitotic prophase and prometaphase, and in prophase relies on the activity of condensin II complexes. Exactly when and how sister <span class="hlt">chromatid</span> resolution occurs has been largely unknown, as has its molecular requirements. Here, we established a method to visualize sister resolution by sequential replication labelling with two distinct nucleotide derivatives. Quantitative three-dimensional imaging then allowed us to measure the resolution of sister <span class="hlt">chromatids</span> throughout mitosis by calculating their non-overlapping volume within the whole chromosome. Unexpectedly, we found that sister <span class="hlt">chromatid</span> resolution starts already at the beginning of prophase, proceeds concomitantly with chromatin compaction and is largely completed by the end of prophase. Sister <span class="hlt">chromatid</span> resolution was abolished by inhibition of topoisomerase IIα and by depleting or preventing mitotic activation of condensin II, whereas blocking cohesin dissociation from chromosomes had little effect. Mitotic sister <span class="hlt">chromatid</span> resolution is thus an intrinsic part of mitotic chromosome formation in prophase that relies largely on DNA decatenation and shares the molecular requirement for condensin II with prophase compaction. PMID:27136266</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SSCom.230...11C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SSCom.230...11C"><span id="translatedtitle">Tiny Ni-NiO nanocrystals with <span class="hlt">exchange</span> bias <span class="hlt">induced</span> room temperature ferromagnetism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaghouri, Hanan Al; Tuna, F.; Santhosh, P. N.; Thomas, P. John</p> <p>2016-03-01</p> <p>Ni nanocrystals coated with a thin layer of NiO with a diameter of 5.0 nm show <span class="hlt">exchange</span> bias <span class="hlt">induced</span> ferromagnetism at room temperature. These particulates are freely dispersible in water and were obtained by annealing Ni nanoparticles coated with a thin amorphous layer of NiO. Particulates with diameters between 5.0 and 16.8 nm are studied. Detailed magnetic measurements reveal signs consistent with strong <span class="hlt">exchange</span> bias including elevated blocking temperatures and tangible loop shifts. The structure of the particulates are characterized by high resolution transmission electron microscopy, energy dispersive x-ray analysis and x-ray diffraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4933981','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4933981"><span id="translatedtitle">Plasma <span class="hlt">exchange</span> in the treatment of thyroid storm secondary to type II amiodarone-<span class="hlt">induced</span> thyrotoxicosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zainudin, Sueziani Binte; Kaushik, Manish; Khor, Li Yan; Chng, Chiaw Ling</p> <p>2016-01-01</p> <p>Summary Type II amiodarone-<span class="hlt">induced</span> thyrotoxicosis (AIT) is an uncommon cause of thyroid storm. Due to the rarity of the condition, little is known about the role of plasma <span class="hlt">exchange</span> in the treatment of severe AIT. A 56-year-old male presented with thyroid storm 2months following cessation of amiodarone. Despite conventional treatment, his condition deteriorated. He underwent two cycles of plasma <span class="hlt">exchange</span>, which successfully controlled the severe hyperthyroidism. The thyroid hormone levels continued to fall up to 10h following plasma <span class="hlt">exchange</span>. He subsequently underwent emergency total thyroidectomy and the histology of thyroid gland confirmed type II AIT. Management of thyroid storm secondary to type II AIT can be challenging as patients may not respond to conventional treatments, and thyroid storm may be more harmful in AIT patients owing to the underlying cardiac disease. If used appropriately, plasma <span class="hlt">exchange</span> can effectively reduce circulating hormones, to allow stabilisation of patients in preparation for emergency thyroidectomy. Learning points Type II AIT is an uncommon cause of thyroid storm and may not respond well to conventional thyroid storm treatment. Prompt diagnosis and therapy are important, as patients may deteriorate rapidly. Plasma <span class="hlt">exchange</span> can be used as an effective bridging therapy to emergency thyroidectomy. This case shows that in type II AIT, each cycle of plasma <span class="hlt">exchange</span> can potentially lower free triiodothyronine levels for 10h. Important factors to consider when planning plasma <span class="hlt">exchange</span> as a treatment for thyroid storm include timing of each session, type of <span class="hlt">exchange</span> fluid to be used and timing of surgery. PMID:27398220</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/153685','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/153685"><span id="translatedtitle">Novel ion-<span class="hlt">exchange</span> membranes for electrodialysis prepared by radiation-<span class="hlt">induced</span> graft polymerization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsuneda, Satoshi; Saito, Kyoichi; Misuhara, Hisashi; Sugo, Takanobu</p> <p>1995-11-01</p> <p>Ion-<span class="hlt">exchange</span> membranes have been used to concentrate seawater to produce salt as well as to desalinate brackish water to render it potable. Also, the interest in applications of ion-<span class="hlt">exchange</span> membranes as separators for electrodialytic desalination of bioproducts and separators in hydrogen-oxygen fuel cells has been growing. Novel ion-<span class="hlt">exchange</span> membranes containing sulfonic acid (SO{sub 3}H) and trimethyl ammonium [N(CH{sub 3}){sub 3}] groups were prepared by a simple method of radiation-<span class="hlt">induced</span> cografting of sodium styrene sulfonate (SSS) with acrylic acid (AAc) and vinyl benzyl trimethyl ammonium chloride (VBTAC) with 2-hydroxyethyl methacrylate (HEMA), onto a polyethylene film with a thickness of 50 {micro}m. The high density graft chain was introduced throughout the polyethylene film. The maximum cation- and anion-<span class="hlt">exchange</span> capacities of the resultant membranes were 2.5 and 1.3 mol/kg, receptively. These membranes exhibited an electrical resistance one order lower than commercially available ion-<span class="hlt">exchange</span> membranes; for example, 12 h cografting provided cation- and anion-<span class="hlt">exchange</span> membranes whose electrical resistances in a 0.5 M NaCl solution were 0.25 and 0.85 {Omega} cm{sup 2}, respectively. From the evaluation of electrodialytic desalination in a batch mode, using a pair of the graft-type ion-<span class="hlt">exchange</span> membranes, the time required to achieve 99.5% desalination of the initial 0.5 M NaCl solutions was reduced to 85% comparing with that of the commercial ion-<span class="hlt">exchange</span> membranes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3575537','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3575537"><span id="translatedtitle">Condensin II initiates sister <span class="hlt">chromatid</span> resolution during S phase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ono, Takao; Yamashita, Daisuke</p> <p>2013-01-01</p> <p>Condensins I and II are multisubunit complexes that play essential yet distinct functions in chromosome condensation and segregation in mitosis. Unlike condensin I, condensin II localizes to the nucleus during interphase, but it remains poorly understood what functions condensin II might have before mitotic entry. Here, we report that condensin II changes its chromatin-binding property during S phase. Remarkably, advanced premature chromosome condensation (PCC) assays enabled us to visualize condensin II forming “sister axes” in replicated regions of chromosomes in S phase cells. Depletion of condensin II compromised PCC-driven sister <span class="hlt">chromatid</span> resolution during S phase. Moreover, fluorescence in situ hybridization assays revealed that condensin II, but not condensin I, promotes disjoining duplicated chromosomal loci during S phase. Application of mild replicative stress partially impaired this process and further exacerbated phenotypes arising from condensin II depletion. Our results suggest that condensin II initiates structural reorganization of duplicated chromosomes during S phase to prepare for their proper condensation and segregation in mitosis. PMID:23401001</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567865','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567865"><span id="translatedtitle">Shugoshin1 May Play Important Roles in Separation of Homologous Chromosomes and Sister <span class="hlt">Chromatids</span> during Mouse Oocyte Meiosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yin, Shen; Ai, Jun-Shu; Shi, Li-Hong; Wei, Liang; Yuan, Ju; Ouyang, Ying-Chun; Hou, Yi; Chen, Da-Yuan; Schatten, Heide; Sun, Qing-Yuan</p> <p>2008-01-01</p> <p>Background Homologous chromosomes separate in meiosis I and sister <span class="hlt">chromatids</span> separate in meiosis II, generating haploid gametes. To address the question why sister <span class="hlt">chromatids</span> do not separate in meiosis I, we explored the roles of Shogoshin1 (Sgo1) in chromosome separation during oocyte meiosis. Methodology/Principal Findings Sgo1 function was evaluated by exogenous overexpression to enhance its roles and RNAi to suppress its roles during two meioses of mouse oocytes. Immunocytochemistry and chromosome spread were used to evaluate phenotypes. The exogenous Sgo1 overexpression kept homologous chromosomes and sister <span class="hlt">chromatids</span> not to separate in meiosis I and meiosis II, respectively, while the Sgo1 RNAi promoted premature separation of sister <span class="hlt">chromatids</span>. Conclusions Our results reveal that prevention of premature separation of sister <span class="hlt">chromatids</span> in meiosis I requires the retention of centromeric Sgo1, while normal separation of sister <span class="hlt">chromatids</span> in meiosis II requires loss of centromeric Sgo1. PMID:18949044</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22162960','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22162960"><span id="translatedtitle">Boron- and phosphorus-doped polycrystalline silicon thin films prepared by silver-<span class="hlt">induced</span> layer <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Antesberger, T.; Wassner, T. A.; Jaeger, C.; Algasinger, M.; Kashani, M.; Scholz, M.; Matich, S.; Stutzmann, M.</p> <p>2013-05-27</p> <p>Intentional boron and phosphorus doping of polycrystalline silicon thin films on glass prepared by the silver-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> is presented. A silver/(titanium) oxide/amorphous silicon stack is annealed at temperatures below the eutectic temperature of the Ag/Si system, leading to a complete layer <span class="hlt">exchange</span> and simultaneous crystallization of the amorphous silicon. Intentional doping of the amorphous silicon prior to the <span class="hlt">exchange</span> process results in boron- or phosphorus-doped polycrystalline silicon. Hall effect measurements show carrier concentrations between 2 Multiplication-Sign 10{sup 17} cm{sup -3} and 3 Multiplication-Sign 10{sup 20} cm{sup -3} for phosphorus and 4 Multiplication-Sign 10{sup 18} cm{sup -3} to 3 Multiplication-Sign 10{sup 19} cm{sup -3} for boron-doped layers, with carrier mobilities up to 90 cm{sup 2}/V s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=461013','PMC'); return false;" href="http://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/2015Nanot..26D5602T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanot..26D5602T"><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="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tyagi, Pawan; Baker, Collin; D'Angelo, Christopher</p> <p>2015-07-01</p> <p>This paper reports our Monte Carlo (MC) studies aiming to explain the experimentally observed paramagnetic molecule <span class="hlt">induced</span> antiferromagnetic coupling between ferromagnetic (FM) electrodes. Recently developed magnetic tunnel junction based molecular spintronics devices (MTJMSDs) were prepared by chemically bonding the paramagnetic molecules between the FM electrodes along the tunnel junction’s perimeter. These MTJMSDs exhibited molecule-<span class="hlt">induced</span> strong antiferromagnetic coupling. We simulated the 3D atomic model analogous to the MTJMSD and studied the effect of molecule’s magnetic couplings with the two FM electrodes. Simulations show that when a molecule established ferromagnetic coupling with one electrode and antiferromagnetic coupling with the other electrode, then theoretical results effectively explained the experimental findings. Our studies suggest that in order to align MTJMSDs’ electrodes antiparallel to each other, the <span class="hlt">exchange</span> coupling strength between a molecule and FM electrodes should be ˜50% of the interatomic <span class="hlt">exchange</span> coupling for the FM electrodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26159362','PUBMED'); return false;" href="http://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="http://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. PMID:26159362</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('http://www.ncbi.nlm.nih.gov/pubmed/27170622','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27170622"><span id="translatedtitle">High density of REC8 constrains sister <span class="hlt">chromatid</span> axes and prevents illegitimate synaptonemal complex formation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Agostinho, Ana; Manneberg, Otto; van Schendel, Robin; Hernández-Hernández, Abrahan; Kouznetsova, Anna; Blom, Hans; Brismar, Hjalmar; Höög, Christer</p> <p>2016-06-01</p> <p>During meiosis, cohesin complexes mediate sister <span class="hlt">chromatid</span> cohesion (SCC), synaptonemal complex (SC) assembly and synapsis. Here, using super-resolution microscopy, we imaged sister <span class="hlt">chromatid</span> axes in mouse meiocytes that have normal or reduced levels of cohesin complexes, assessing the relationship between localization of cohesin complexes, SCC and SC formation. We show that REC8 foci are separated from each other by a distance smaller than 15% of the total chromosome axis length in wild-type meiocytes. Reduced levels of cohesin complexes result in a local separation of sister <span class="hlt">chromatid</span> axial elements (LSAEs), as well as illegitimate SC formation at these sites. REC8 but not RAD21 or RAD21L cohesin complexes flank sites of LSAEs, whereas RAD21 and RAD21L appear predominantly along the separated sister-<span class="hlt">chromatid</span> axes. Based on these observations and a quantitative distribution analysis of REC8 along sister <span class="hlt">chromatid</span> axes, we propose that the high density of randomly distributed REC8 cohesin complexes promotes SCC and prevents illegitimate SC formation. PMID:27170622</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22374834','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22374834"><span id="translatedtitle">Accurate quantification of water-macromolecule <span class="hlt">exchange</span> <span class="hlt">induced</span> frequency shift: effects of reference substance.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leutritz, Tobias; Hilfert, Liane; Smalla, Karl-Heinz; Speck, Oliver; Zhong, Kai</p> <p>2013-01-01</p> <p>Water-macromolecule <span class="hlt">exchange</span> <span class="hlt">induces</span> a bulk water frequency shift contributing to the contrast in phase imaging. For separating the effects of the water-macromolecule <span class="hlt">exchange</span> and the macromolecule susceptibility, appropriate internal or external references are needed. In this study, two internal reference compounds, 2,2,3,3-tetradeuterio-3-trimethylsilyl-propionate (TMSP) and 1,4-dioxane, were used to study the macromolecule-dependent water frequency shift in a bovine serum albumin (BSA)-water system in detail. For TMSP, the water-macromolecule <span class="hlt">exchange</span> shift depended on both the BSA and the reference concentration and stabilized to a value of 0.025 ppm/mM (298 K, TMSP concentrations > 30 mM). For dioxane, the dependency of the water-macromolecule <span class="hlt">exchange</span> shift on the BSA concentration is independent of dioxane at low concentrations. The resulting shift was smaller (0.009 ppm/mM) when compared with using higher TMSP concentrations as reference. This discrepancy might be due to additional dioxane-water interactions. Measurements with an external chloroform reference in a coaxial geometry showed a shift of -0.013 ppm/mM resulting from the opposing effects of macromolecules in water <span class="hlt">exchange-induced</span> shift and diamagnetic susceptibility shift. All these effects should be considered in the interpretation of tissue phase contrast. From the experimental data, the equilibrium binding constant between BSA and TMSP has been quantified to be K(d) = 1.3 ± 0.4, and the estimated number of interaction sites for BSA is 12.7 ± 2.6. PMID:22374834</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=ocean+AND+currents&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=65307677&CFTOKEN=54495834','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=69342&keyword=ocean+AND+currents&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=65307677&CFTOKEN=54495834"><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> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJD...70..120H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJD...70..120H"><span id="translatedtitle">The weakening of fermionization of one dimensional spinor Bose gases <span class="hlt">induced</span> by spin-<span class="hlt">exchange</span> interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hao, Yajiang</p> <p>2016-05-01</p> <p>We investigate the ground state density distributions of anti-ferromagnetic spin-1 Bose gases in a one dimensional harmonic potential in the full interacting regimes. The ground state is obtained by diagonalizing the Hamiltonian in the Hilbert space composed of the lowest eigenstates of noninteracting Bose gas and spin components. The study reveals that in the situation of a weak spin-dependent interaction the total density profiles evolve from a Gaussian-like distribution to a Fermi-like shell structure of N peaks with the increasing of spin-independent interaction. The increasing spin-<span class="hlt">exchange</span> interaction always weakens the fermionization of the density distribution such that the total density profiles show the shell structure of less peaks and even show single peak structure in the limit of the strong spin-<span class="hlt">exchange</span> interaction. The weakening of fermionization results from the formation of composite atoms <span class="hlt">induced</span> by the spin-<span class="hlt">exchange</span> interaction. It is also shown that phase separation occurs for the spinor Bose gas with a weak spin-<span class="hlt">exchange</span> interaction, meanwhile the spin-independent interaction is strong.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016RaPC..118...35K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016RaPC..118...35K&link_type=ABSTRACT"><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/2014JMagR.245...12S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMagR.245...12S"><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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sorce, Dennis J.; Mangia, Silvia; Liimatainen, Timo; Garwood, Michael; Michaeli, Shalom</p> <p>2014-08-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24911888','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24911888"><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=pubmed">PubMed</a></p> <p>Sorce, Dennis J; Mangia, Silvia; Liimatainen, Timo; Garwood, Michael; Michaeli, Shalom</p> <p>2014-08-01</p> <p>In the present study we derive a solution for two site fast <span class="hlt">exchange-induced</span> relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n=2 are derived for the fast <span class="hlt">exchange</span> regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n>2. PMID:24911888</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308052','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308052"><span id="translatedtitle"><span class="hlt">Exchange-Induced</span> Relaxation in the Presence of a Fictitious Field</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sorce, Dennis J.; Mangia, Silvia; Liimatainen, Timo; Garwood, Michael; Michaeli, Shalom</p> <p>2014-01-01</p> <p>In the present study we derive a solution for two site fast <span class="hlt">exchange-induced</span> relaxation in the presence of a fictitious magnetic field as generated by amplitude and frequency modulated RF pulses. This solution provides a means to analyze data obtained from relaxation experiments with the method called RAFFn (Relaxation Along a Fictitious Field of rank n), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (rank n). The RAFF2 technique is relevant to MRI relaxation methods that provide good contrast enhancement for tumor detection. The relaxation equations for n = 2 are derived for the fast <span class="hlt">exchange</span> regime using density matrix formalism. The method of derivation can be further extended to obtain solutions for n > 2. PMID:24911888</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4358958','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4358958"><span id="translatedtitle"><span class="hlt">Inducible</span> and Reversible Lentiviral and Recombination Mediated Cassette <span class="hlt">Exchange</span> (RMCE) Systems for Controlling 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>Bersten, David C.; Sullivan, Adrienne E.; Li, Dian; Bhakti, Veronica; Bent, Stephen J.; Whitelaw, Murray L.</p> <p>2015-01-01</p> <p>Manipulation of gene expression to invoke loss of function (LoF) or gain of function (GoF) phenotypes is important for interrogating complex biological questions both in vitro and in vivo. Doxycycline (Dox)-<span class="hlt">inducible</span> gene expression systems are commonly used although success is often limited by high background and insufficient sensitivity to Dox. Here we develop broadly applicable platforms for reliable, tightly controlled and reversible Dox-<span class="hlt">inducible</span> systems for lentiviral mediated generation of cell lines or FLP Recombination-Mediated Cassette <span class="hlt">Exchange</span> (RMCE) into the Collagen 1a1 (Col1a1) locus (FLP-In Col1a1) in mouse embryonic stem cells. We significantly improve the flexibility, usefulness and robustness of the Dox-<span class="hlt">inducible</span> system by using Tetracycline (Tet) activator (Tet-On) variants which are more sensitive to Dox, have no background activity and are expressed from single Gateway-compatible constructs. We demonstrate the usefulness of these platforms in ectopic gene expression or gene knockdown in multiple cell lines, primary neurons and in FLP-In Col1a1 mouse embryonic stem cells. We also improve the flexibility of RMCE Dox-<span class="hlt">inducible</span> systems by generating constructs that allow for tissue or cell type-specific Dox-<span class="hlt">inducible</span> expression and generate a shRNA selection algorithm that can effectively predict potent shRNA sequences able to knockdown gene expression from single integrant constructs. These platforms provide flexible, reliable and broadly applicable <span class="hlt">inducible</span> expression systems for studying gene function. PMID:25768837</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25795300','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25795300"><span id="translatedtitle">Rho guanine nucleotide <span class="hlt">exchange</span> factors involved in cyclic-stretch-<span class="hlt">induced</span> reorientation of vascular endothelial cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abiko, Hiyori; Fujiwara, Sachiko; Ohashi, Kazumasa; Hiatari, Ryuichi; Mashiko, Toshiya; Sakamoto, Naoya; Sato, Masaaki; Mizuno, Kensaku</p> <p>2015-05-01</p> <p>Cyclic stretch is an artificial model of mechanical force loading, which <span class="hlt">induces</span> the reorientation of vascular endothelial cells and their stress fibers in a direction perpendicular to the stretch axis. Rho family GTPases are crucial for cyclic-stretch-<span class="hlt">induced</span> endothelial cell reorientation; however, the mechanism underlying stretch-<span class="hlt">induced</span> activation of Rho family GTPases is unknown. A screen of short hairpin RNAs targeting 63 Rho guanine nucleotide <span class="hlt">exchange</span> factors (Rho-GEFs) revealed that at least 11 Rho-GEFs – Abr, alsin, ARHGEF10, Bcr, GEF-H1 (also known as ARHGEF2), LARG (also known as ARHGEF12), p190RhoGEF (also known as ARHGEF28), PLEKHG1, P-REX2, Solo (also known as ARHGEF40) and α-PIX (also known as ARHGEF6) – which specifically or broadly target RhoA, Rac1 and/or Cdc42, are involved in cyclic-stretch-<span class="hlt">induced</span> perpendicular reorientation of endothelial cells. Overexpression of Solo <span class="hlt">induced</span> RhoA activation and F-actin accumulation at cell-cell and cell-substrate adhesion sites. Knockdown of Solo suppressed cyclic-stretch- or tensile-force-<span class="hlt">induced</span> RhoA activation. Moreover, knockdown of Solo significantly reduced cyclic-stretch-<span class="hlt">induced</span> perpendicular reorientation of endothelial cells when cells were cultured at high density, but not when they were cultured at low density or pretreated with EGTA or VE-cadherin-targeting small interfering RNAs. These results suggest that Solo is involved in cell-cell-adhesion-mediated mechanical signal transduction during cyclic-stretch-<span class="hlt">induced</span> endothelial cell reorientation. PMID:25795300</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApPhB..80..193W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApPhB..80..193W"><span id="translatedtitle">Wavelength-tunable polarization converter utilizing the strain <span class="hlt">induced</span> by proton <span class="hlt">exchange</span> in lithium niobate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, T.-J.; Chung, J.-S.</p> <p>2005-02-01</p> <p>A new wavelength-tunable polarization converter utilizing the strain <span class="hlt">induced</span> by proton <span class="hlt">exchange</span> is demonstrated in x-cut LiNbO3. The light polarization is converted by the strain-optic effect through the phase-matched coupling of two orthogonal polarizations. The stress-applying structure is designed to be composed of several proton-<span class="hlt">exchanged</span> strip regions for maximization of the stress distribution. The principle of birefringent chain filters is utilized to design the device structure in order to avoid the requirement of large stress, which results in serious cracks on the substrate surface. The overlap integral between the optical field distribution and the stress distribution can be enhanced simply by prolonging the proton-<span class="hlt">exchange</span> time. Besides, the stress distribution and its strength in the stress-applying structure can be fine tuned without affecting the waveguide characteristics such that the principle of the birefringent chain filters is completely satisfied. Therefore, the polarization-conversion efficiency can be optimized when utilizing this exclusive stress-tuning ability. By the thermal-optic effect, the wavelength of maximum conversion can be tuned at a rate of -0.115 nm/°C with a maximum conversion efficiency of 92.41%. The proposed polarization converter has the advantages of adequate stress distribution and strength, high parameter-tuning feasibility, low propagation loss, easy fabrication, and low fabrication cost.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25962614','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25962614"><span id="translatedtitle">The effects of oxygen <span class="hlt">induced</span> pulmonary vasoconstriction on bedside measurement of pulmonary gas <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weinreich, Ulla M; Thomsen, Lars P; Rees, Stephen E; Rasmussen, Bodil S</p> <p>2016-04-01</p> <p>In patients with respiratory failure measurements of pulmonary gas <span class="hlt">exchange</span> are of importance. The bedside automatic lung parameter estimator (ALPE) of pulmonary gas <span class="hlt">exchange</span> is based on changes in inspired oxygen (FiO2) assuming that these changes do not affect pulmonary circulation. This assumption is investigated in this study. Forty-two out of 65 patients undergoing coronary artery bypass grafting (CABG) had measurements of mean pulmonary arterial pressure (MPAP), cardiac output and pulmonary capillary wedge pressure thus enabling the calculation of pulmonary vascular resistance (PVR) at each FiO2 level. The research version of ALPE was used and FiO2 was step-wise reduced a median of 0.20 and ultimately returned towards baseline values, allowing 6-8 min' steady state period at each of 4-6 levels before recording the oxygen saturation (SpO2). FiO2 reduction led to median decrease in SpO2 from 99 to 92 %, an increase in MPAP of 4 mmHg and an increase in PVR of 36 dyn s cm(-5). Changes were immediately reversed on returning FiO2 towards baseline. In this study changes in MPAP and PVR are small and immediately reversible consistent with small changes in pulmonary gas <span class="hlt">exchange</span>. This indicates that mild deoxygenation <span class="hlt">induced</span> pulmonary vasoconstriction does not have significant influences on the ALPE parameters in patients after CABG. PMID:25962614</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25319531','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25319531"><span id="translatedtitle">Uncoupled surface spin <span class="hlt">induced</span> <span class="hlt">exchange</span> bias in α-MnO2 nanowires.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Wenxian; Zeng, Rong; Sun, Ziqi; Tian, Dongliang; Dou, Shixue</p> <p>2014-01-01</p> <p>We have studied the microstructure, surface states, valence fluctuations, magnetic properties, and <span class="hlt">exchange</span> bias effect in MnO2 nanowires. High purity α-MnO2 rectangular nanowires were synthesized by a facile hydrothermal method with microwave-assisted procedures. The microstructure analysis indicates that the nanowires grow in the [0 0 1] direction with the (2 1 0) plane as the surface. Mn(3+) and Mn(2+) ions are not found in the system by X-ray photoelectron spectroscopy. The effective magnetic moment of the manganese ions fits in with the theoretical and experimental values of Mn(4+) very well. The uncoupled spins in 3d(3) orbitals of the Mn(4+) ions in MnO6 octahedra on the rough surface are responsible for the net magnetic moment. Spin glass behavior is observed through magnetic measurements. Furthermore, the <span class="hlt">exchange</span> bias effect is observed for the first time in pure α-MnO2 phase due to the coupling of the surface spin glass with the antiferromagnetic α-MnO2 matrix. These α-MnO2 nanowires, with a spin-glass-like behavior and with an <span class="hlt">exchange</span> bias effect excited by the uncoupled surface spins, should therefore inspire further study concerning the origin, theory, and applicability of surface structure <span class="hlt">induced</span> magnetism in nanostructures. PMID:25319531</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E6641L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E6641L"><span id="translatedtitle">Uncoupled surface spin <span class="hlt">induced</span> <span class="hlt">exchange</span> bias in α-MnO2 nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Wenxian; Zeng, Rong; Sun, Ziqi; Tian, Dongliang; Dou, Shixue</p> <p>2014-10-01</p> <p>We have studied the microstructure, surface states, valence fluctuations, magnetic properties, and <span class="hlt">exchange</span> bias effect in MnO2 nanowires. High purity α-MnO2 rectangular nanowires were synthesized by a facile hydrothermal method with microwave-assisted procedures. The microstructure analysis indicates that the nanowires grow in the [0 0 1] direction with the (2 1 0) plane as the surface. Mn3+ and Mn2+ ions are not found in the system by X-ray photoelectron spectroscopy. The effective magnetic moment of the manganese ions fits in with the theoretical and experimental values of Mn4+ very well. The uncoupled spins in 3d3 orbitals of the Mn4+ ions in MnO6 octahedra on the rough surface are responsible for the net magnetic moment. Spin glass behavior is observed through magnetic measurements. Furthermore, the <span class="hlt">exchange</span> bias effect is observed for the first time in pure α-MnO2 phase due to the coupling of the surface spin glass with the antiferromagnetic α-MnO2 matrix. These α-MnO2 nanowires, with a spin-glass-like behavior and with an <span class="hlt">exchange</span> bias effect excited by the uncoupled surface spins, should therefore inspire further study concerning the origin, theory, and applicability of surface structure <span class="hlt">induced</span> magnetism in nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198866','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198866"><span id="translatedtitle">Uncoupled surface spin <span class="hlt">induced</span> <span class="hlt">exchange</span> bias in α-MnO2 nanowires</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Wenxian; Zeng, Rong; Sun, Ziqi; Tian, Dongliang; Dou, Shixue</p> <p>2014-01-01</p> <p>We have studied the microstructure, surface states, valence fluctuations, magnetic properties, and <span class="hlt">exchange</span> bias effect in MnO2 nanowires. High purity α-MnO2 rectangular nanowires were synthesized by a facile hydrothermal method with microwave-assisted procedures. The microstructure analysis indicates that the nanowires grow in the [0 0 1] direction with the (2 1 0) plane as the surface. Mn3+ and Mn2+ ions are not found in the system by X-ray photoelectron spectroscopy. The effective magnetic moment of the manganese ions fits in with the theoretical and experimental values of Mn4+ very well. The uncoupled spins in 3d3 orbitals of the Mn4+ ions in MnO6 octahedra on the rough surface are responsible for the net magnetic moment. Spin glass behavior is observed through magnetic measurements. Furthermore, the <span class="hlt">exchange</span> bias effect is observed for the first time in pure α-MnO2 phase due to the coupling of the surface spin glass with the antiferromagnetic α-MnO2 matrix. These α-MnO2 nanowires, with a spin-glass-like behavior and with an <span class="hlt">exchange</span> bias effect excited by the uncoupled surface spins, should therefore inspire further study concerning the origin, theory, and applicability of surface structure <span class="hlt">induced</span> magnetism in nanostructures. PMID:25319531</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/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('http://adsabs.harvard.edu/abs/2012EGUGA..14.9059B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9059B"><span id="translatedtitle">Modeling dune-<span class="hlt">induced</span> hyporheic <span class="hlt">exchange</span> and nutrient reactions in stream sediments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bardini, L.; Boano, F.; Cardenas, M. B.; Revelli, R.; Ridolfi, L.</p> <p>2012-04-01</p> <p>The <span class="hlt">exchange</span> of water across the streambed plays an important role in the ecology of fluvial environments, since it assures the connections of surface and subsurface waters, which have very different peculiarities. Water-borne chemicals are also involved in the process: they enter the sediments with the water and they are transformed into oxidized or reduced substances by biogeochemical reactions, mediated by the hyporheic microbiota. In particular, organic substances can be used as electron donors in a series of redox reactions, with different electron acceptors, e.g., oxygen and nitrate. Nitrification and other secondary reactions also occur as soon as water enters the streambed. These pore-scale transformations concur to affect subsurface solute concentrations and, consequently, the chemistry of upwelling water and the quality of the stream environment. The <span class="hlt">exchange</span> with the hyporheic zone occurs in response to variations in bed topography, with a very wide range of spatial and temporal scales. For instance, small-scale <span class="hlt">exchanges</span> are mainly <span class="hlt">induced</span> by river bed forms, like ripples and dunes, while large-scale <span class="hlt">exchanges</span> depend on larger geomorphological features. In this work we focus on small-scale <span class="hlt">exchange</span> <span class="hlt">induced</span> by the presence of dunes on the streambed, investigating the interplay of hydrological and biogeochemical processes and their effects on solute spatial distribution in the sediments. We numerically simulate the turbulent water flow and the pressure distribution on the streambed and then we evaluate the coupled flow field and biogeochemical reactions in the hyporheic zone in steady-state conditions. Four representative reactive compounds are taken into account: dissolved organic carbon (DOC), oxygen (O2), nitrate (NO3-) and ammonium (NH4+). Sensitivity analyses are also performed to analyze the influence of hydrological and chemical properties of the system on solute reaction rates. The results demonstrate that the stream water quality can strongly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP43C3583L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP43C3583L"><span id="translatedtitle">Hyporheic <span class="hlt">exchange</span> <span class="hlt">induced</span> by channel-spanning obstacles in a coarse, highly-permeable laboratory streambed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lichtner, D.; Best, J.; Blois, G.; Kim, T.; Christensen, K. T.</p> <p>2014-12-01</p> <p>Knowledge of flow over and through a porous streambed is essential to understanding hyporheic <span class="hlt">exchange</span> in coarse gravel-bed rivers, where turbulence in the stream flow can penetrate significantly into the streambed. To study the turbulent momentum <span class="hlt">exchange</span> between a stream and gravel streambed, laboratory experiments were conducted in a 2.5 m long refractive-index matching (RIM) laboratory flume. A flat gravel bed was simulated using cubically packed acrylic spheres (Ds = 1.27 cm) with a refractive index, RI = 1.495, that matched that of the NaI solution in the flume. Thus, optical access to the pore spaces could be gained, and the flow field from the near-bed and into the pore spaces could be measured with particle image velocimetry (PIV). Dense 2-D velocity vector fields were measured for two bed configurations: (1) a flat, porous, bed composed of three layers of spheres and (2) a flat bed with a cylinder (Dc = 1.27 cm) placed atop it, to <span class="hlt">induce</span> hyporheic <span class="hlt">exchange</span> in the manner of a channel-spanning large woody debris. The flow over and through the bed produced by the cylinder is found to be dramaticallydifferent from that associated with a flat bed. The mean velocity field produced by the cylinder exhibited strong flow downwelling in the pore space immediately upstream of the cylinder and upwelling several pore spaces downstream. In particular, the shear layer separating from the cylinder remained parallel to the bed from the point of flow separation to the edge of the field of view, instead of reattaching several grain diameters downstream. The cylinder also promoted increased vertical momentum <span class="hlt">exchange</span> as suggested by turbulent kinetic energy maps.</p> </li> <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.ncbi.nlm.nih.gov/pubmed/25970916','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25970916"><span id="translatedtitle">[Piezoresistivity of ultra-thin poly-silicon layer by aluminum-<span class="hlt">induced</span> layer <span class="hlt">exchange</span>].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Cheng-long; Ma, Jun; Fan, Duo-wang; Xing, Da; Liu, Song-hao</p> <p>2015-02-01</p> <p>Poly-Si film, due to its favorable piezoresistive properties, has been widely used in piezoresistive sensors. The previous researches have shown that the ultra-thin poly-Si film have better piezoresistive properties than common poly-silicon film, and have promising future of application. A promising method to obtain large grained high quality poly-silicon films by low-temperature crystallization of an amorphous precursor material is the aluminum-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> (ALILE). In this paper, ultra-thin poly-Si films were prepared by aluminum <span class="hlt">induced</span> layer <span class="hlt">exchange</span> (ALILE). Experimental results of Raman spectroscopy show that a narrow and symmetrical Raman peak at the wave number of about 518 cm(-1) was observed for all samples, indicating that the films were fully crystallized. XRD results show that the crystallites of ultra-thin poly-silicon layer were preferably (111) and (220) oriented. Hall affect measurements show that hole concentration of the films (p-type) were between 9 x 10(18) and 6 x 10(19) cm(-3). Restorative properties show that the piezoresistors exhibit gauge factors (GFs) up to 60, with temperature coefficients of GF (TCGF) between -0.17-0% degree C and temperature coefficients of resistance (TCR) between -0.2 and -0.1% degrees C. The study of the ultra-thin poly-Si films by ALILE is completed, and the study results lay a foundation for application of the film PMID:25970916</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://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528Y%2Bchromosome%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040088723&hterms=chromosome&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528Y%2Bchromosome%2529"><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> </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://www.ncbi.nlm.nih.gov/pubmed/24955171','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24955171"><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=pubmed">PubMed</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('http://www.ncbi.nlm.nih.gov/pubmed/23756266','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23756266"><span id="translatedtitle">Role of plasma <span class="hlt">exchange</span> in autoimmune hyperthyroidism complicated by severe tiamazol-<span class="hlt">induced</span> cholestatic jaundice.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miljić, D; Stojanović, M; Ješić, R; Bogadnović, G; Popović, V</p> <p>2013-10-01</p> <p>Therapeutic plasma <span class="hlt">exchange</span> (TPE) is an alternative treatment for hyperthyroidism, resulting in a rapid decline in plasma thyroid hormones and anti-thyroid antibodies. TPE has also been used both in primary liver disease and in drug-<span class="hlt">induced</span> cholestasis. Data on thyrotoxic patients with severe hepatic complications are scarce. Cholestasis <span class="hlt">induced</span> by imidazol-derived anti-thyroid drugs is extremely rare. The use of TPE for treating this complication was not previously reported. We report the experience of one such patient with a favorable response to TPE. A 45-year-old male patient with Graves' disease, presented with severe jaundice and extremely high serum bilirubin levels due to hepatotoxicity <span class="hlt">induced</span> by tiamazol. Through extensive investigation primary liver disease, including viral, metabolic, neoplastic and autoimmune disease, as a cause of cholestasis were all ruled out. The patient underwent total of 6 TPEs which in combination with low dose of glucocorticoids and standard supportive measures, resulted in normalization of thyroid hormones and normal liver function tests. TPE provided a safe, rapid and effective treatment of severe drug-<span class="hlt">induced</span> cholestasis and auto immune hyperthyroidism. From this case we conclude that TPE should be considered as a valuable alternative therapeutic option in thyrotoxic patients with severe complications. Guidelines and indication criteria for TPE treatment in patients with hyperthyroidism are still lacking. PMID:23756266</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15254761','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15254761"><span id="translatedtitle">The Na+/H+ <span class="hlt">exchange</span> inhibitor HOE642 prevents stress-<span class="hlt">induced</span> epithelial barrier dysfunction.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nowak, Peter; Blaheta, Roman; Schuller, Alina; Cinatl, Jindrich; Wimmer-Greinecker, Gerhard; Moritz, Anton; Scholz, Martin</p> <p>2004-08-01</p> <p>Recently, evidence has been obtained that the Na+/H+ <span class="hlt">exchange</span> (NHE) inhibitor HOE642 may stabilize endothelial and epithelial barrier function in vivo. However, the underlying mechanisms are not known. Therefore, we studied the influence of HOE642 on the barrier function of the epithelial cell line CaCo2. The phorbolester phorbol 12-myristate 13-acetate (PMA) was used to <span class="hlt">induce</span> hyperpermeability of the epithelial layer which was indirectly determined by measuring the transepithelial electrical resistance (TER). Confocal laser scan microscopy (LSM) served to analyze the intracellular localization of adherens and tight junction molecules. In five independent experiments we found that HOE642 increased TER in non-treated CaCo2 cells (control: 350 +/- 28 Omega/cm2; HOE642: 444 +/- 53 Omega/cm2) and prevented PMA-<span class="hlt">induced</span> barrier dysfunction (PMA: 33 +/- 12 Omega/cm2; PMA plus HOE642: 496 +/- 47 Omega/cm2). LSM showed that HOE642 prevented the PMA-<span class="hlt">induced</span> disassociation of the zonula adherens molecule beta-catenin from the cell membrane and the decreased expression of the zonula occludens molecule ZO-1. From our data we conclude that HOE642 may prevent stress-<span class="hlt">induced</span> epithelial dysfunction by stabilization of cell membrane-associated junction molecules. PMID:15254761</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8625980','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8625980"><span id="translatedtitle">A third interferon-gamma-<span class="hlt">induced</span> subunit <span class="hlt">exchange</span> in the 20S proteasome.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Groettrup, M; Kraft, R; Kostka, S; Standera, S; Stohwasser, R; Kloetzel, P M</p> <p>1996-04-01</p> <p>The 20S proteasome is a protease complex of functional importance for antigen processing. Two of the 14 proteasome subunits, delta and MB1, can be replaced by the major histocompatibility complex (MHC)-encoded and interferon-gamma (IFN-gamma)-<span class="hlt">inducible</span> subunits LMP2 and LMP7, respectively. LMP2 and LMP7 alter the cleavage site specificity of the 20S proteasome and are required for the efficient generation of T cell epitopes from a number of viral proteins and for optimal MHC class I cell surface expression. We compared the 20S proteasome subunit pattern from IFN-gamma-<span class="hlt">induced</span> and non-<span class="hlt">induced</span> mouse fibroblasts on two-dimensional gels and identified a third subunit <span class="hlt">exchange</span> by microsequencing: the non-MHC-encoded subunit MECL-1 is <span class="hlt">induced</span> by IFN-gamma and replaces a sofar barely characterized beta subunit designated 'MC14'. In analogy to LMP2 and LMP7, MECL-1 may be functional in MHC class I-restricted antigen presentation. PMID:8625980</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941706','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941706"><span id="translatedtitle">Sodium hydrogen <span class="hlt">exchanger</span> as a mediator of hydrostatic edema <span class="hlt">induced</span> intestinal contractile dysfunction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Uray, Karen S.; Shah, Shinil K.; Radhakrishnan, Ravi S.; Jimenez, Fernando; Walker, Peter A.; Stewart, Randolph H.; Laine, Glen A.; Cox, Charles S.</p> <p>2010-01-01</p> <p>Background Resuscitation-<span class="hlt">induced</span> intestinal edema is associated with early and profound mechanical changes in intestinal tissue. We hypothesize that the sodium hydrogen <span class="hlt">exchanger</span> (NHE), a mechano-responsive ion channel, is a mediator of edema-<span class="hlt">induced</span> intestinal contractile dysfunction. Methods An animal model of hydrostatic intestinal edema was utilized for all experiments. NHE isoforms 1-3 mRNA and protein were evaluated. Subsequently, the effects of NHE inhibition (with 5-(N-ethyl-N-isopropyl) amiloride (EIPA)) on wet to dry ratios, signal transduction and activator of transcription (STAT)-3, intestinal smooth muscle myosin light chain (MLC) phosphorylation, intestinal contractile activity, and intestinal transit were measured. Results NHE1-3 mRNA and protein levels were significantly increased in the small intestinal mucosa with the induction of intestinal edema. Administration of EIPA, an NHE inhibitor, attenuated validated markers of intestinal contractile dysfunction <span class="hlt">induced</span> by edema as measured by decreased STAT-3 activation, increased MLC phosphorylation, improved intestinal contractile activity, and enhanced intestinal transit. Conclusion The mechano-responsive ion channel NHE may mediate edema-<span class="hlt">induced</span> intestinal contractile dysfunction, possibly via a STAT-3 related mechanism. PMID:20553904</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4401699','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4401699"><span id="translatedtitle">Na+/H+ <span class="hlt">Exchanger</span> Isoform 1-<span class="hlt">Induced</span> Osteopontin Expression Facilitates Cardiomyocyte Hypertrophy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mohamed, Iman A.; Gadeau, Alain-Pierre; Fliegel, Larry; Lopaschuk, Gary; Mlih, Mohamed; Abdulrahman, Nabeel; Fillmore, Natasha; Mraiche, Fatima</p> <p>2015-01-01</p> <p>Enhanced expression and activity of the Na+/H+ <span class="hlt">exchanger</span> isoform 1 (NHE1) has been implicated in cardiomyocyte hypertrophy in various experimental models. The upregulation of NHE1 was correlated with an increase in osteopontin (OPN) expression in models of cardiac hypertrophy (CH), and the mechanism for this remains to be delineated. To determine whether the expression of active NHE1-<span class="hlt">induces</span> OPN and contributes to the hypertrophic response in vitro, cardiomyocytes were infected with the active form of the NHE1 adenovirus or transfected with OPN silencing RNA (siRNA-OPN) and characterized for cardiomyocyte hypertrophy. Expression of NHE1 in cardiomyocytes resulted in a significant increase in cardiomyocyte hypertrophy markers: cell surface area, protein content, ANP mRNA and expression of phosphorylated-GATA4. NHE1 activity was also significantly increased in cardiomyocytes expressing active NHE1. Interestingly, transfection of cardiomyocytes with siRNA-OPN significantly abolished the NHE1-<span class="hlt">induced</span> cardiomyocyte hypertrophy. siRNA-OPN also significantly reduced the activity of NHE1 in cardiomyocytes expressing NHE1 (68.5±0.24%; P<0.05), confirming the role of OPN in the NHE1-<span class="hlt">induced</span> hypertrophic response. The hypertrophic response facilitated by NHE1-<span class="hlt">induced</span> OPN occurred independent of the extracellular-signal-regulated kinases and Akt, but required p90-ribosomal S6 kinase (RSK). The ability of OPN to facilitate the NHE1-<span class="hlt">induced</span> hypertrophic response identifies OPN as a potential therapeutic target to reverse the hypertrophic effect <span class="hlt">induced</span> by the expression of active NHE1. PMID:25884410</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JIEx...22...53A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JIEx...22...53A"><span id="translatedtitle">Electrodialysis of Sulfuric Acid with Cation-<span class="hlt">Exchange</span> Membranes Prepared by Electron-Beam-<span class="hlt">Induced</span> Graft Polymerization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asari, Yuki; Shoji, Nobuyoshi; Miyoshi, Kazuyoshi; Umeno, Daisuke; Saito, Kyoichi</p> <p></p> <p>Strongly acidic cation-<span class="hlt">exchange</span> membranes were prepared by the electron-beam-<span class="hlt">induced</span> graft polymerization of glycidyl methacrylate onto a high-density polyethylene film with a thickness of 35 μm and the subsequent conversion of the resulting epoxy group into a sulfonic acid group. The resulting cation-<span class="hlt">exchange</span> membranes with various ion-<span class="hlt">exchange</span> capacities or sulfonic acid group densities ranging from 1.9 to 2.7 mmol/g were applied to the enrichment of 0.50 mol/L sulfuric acid by electrodialysis. Concentrated sulfuric acids at concentrations of 1.4 to 2.9 mol/L were obtained in the concentrate chamber during the electrodialysis operated at 30 mA/cm2 and 298 K, using a pair of this cation-<span class="hlt">exchange</span> membrane and a commercially available anion-<span class="hlt">exchange</span> membrane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25141009','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25141009"><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=pubmed">PubMed</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://www.ncbi.nlm.nih.gov/pubmed/2791669','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2791669"><span id="translatedtitle">Pulmonary gas <span class="hlt">exchange</span> during histamine-<span class="hlt">induced</span> bronchoconstriction in asthmatic subjects.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Burke, T V; Küng, M; Burki, N K</p> <p>1989-10-01</p> <p>Bronchial provocation for testing airway hyperreactivity is now well-established. However, the effects of histamine-<span class="hlt">induced</span> bronchoconstriction on pulmonary gas <span class="hlt">exchange</span> in man have not been systematically studied. We empirically noted marked decreases in PaO2 in some asthmatic subjects following <span class="hlt">induced</span> bronchoconstriction. Nine subjects with mild, stable asthma were studied, each on two separate days. The first determined the dose of inhaled histamine necessary to decrease FEV1 by 20 percent and the relationship to lung volume and to pulmonary resistance by the interrupter technique (Rint). On the second day arterial blood gases, ventilation, Rint, and the anatomic (VDan) and physiologic (VDphys) dead spaces were measured simultaneously. There was a significant (p less than 0.05), profound fall in PaO2 (mean, -21.8 mm Hg) and in P(A-a)O2 (mean +14.7 mm Hg) within 5 min after bronchoconstriction, associated with a significant (p less than 0.05) increase in respiratory frequency (mean +5.1 min-1); and decrease in tidal volume (mean, -0.3 L). The ratio VDphys/VT increased significantly (p less than 0.05; mean change, +0.08) even though VDan and VDphys did not. Bronchoconstriction <span class="hlt">induced</span> the broadening of ventilation (V)/perfusion (Q) ratios, with, most likely, an increase in areas of high V/Q. Histamine-<span class="hlt">induced</span> bronchoconstriction in mild asthma results in a marked fall in PaO2 due to <span class="hlt">induced</span> V/Q inequality. Therefore, histamine airway challenge should be used with caution in patients with any preexisting hypoxemia. PMID:2791669</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4290709','PMC'); return false;" href="http://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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5017209','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5017209"><span id="translatedtitle"><span class="hlt">Exchange</span> factors directly activated by cAMP mediate melanocortin 4 receptor-<span class="hlt">induced</span> gene expression</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Glas, Evi; Mückter, Harald; Gudermann, Thomas; Breit, Andreas</p> <p>2016-01-01</p> <p>Gs protein-coupled receptors regulate many vital body functions by activation of cAMP response elements (CRE) via cAMP-dependent kinase A (PKA)-mediated phosphorylation of the CRE binding protein (CREB). Melanocortin 4 receptors (MC4R) are prototypical Gs-coupled receptors that orchestrate the hypothalamic control of food-intake and metabolism. Remarkably, the significance of PKA for MC4R-<span class="hlt">induced</span> CRE-dependent transcription in hypothalamic cells has not been rigorously interrogated yet. In two hypothalamic cell lines, we observed that blocking PKA activity had only weak or no effects on reporter gene expression. In contrast, inhibitors of <span class="hlt">exchange</span> factors directly activated by cAMP-1/2 (EPAC-1/2) mitigated MC4R-<span class="hlt">induced</span> CRE reporter activation and mRNA induction of the CREB-dependent genes c-fos and thyrotropin-releasing hormone. Furthermore, we provide first evidence that extracellular-regulated kinases-1/2 (ERK-1/2) activated by EPACs and not PKA are the elusive CREB kinases responsible for MC4R-<span class="hlt">induced</span> CREB/CRE activation in hypothalamic cells. Overall, these data emphasize the pivotal role of EPACs rather than PKA in hypothalamic gene expression elicited by a prototypical Gs-coupled receptor. PMID:27612207</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26302862','PUBMED'); return false;" href="http://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="http://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. PMID:26302862</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.105o2402C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.105o2402C"><span id="translatedtitle"><span class="hlt">Exchange</span> bias field <span class="hlt">induced</span> symmetry-breaking of magnetization rotation in two-dimension</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, B.; Song, C.; Sun, Y.; Wang, Y. Y.; Zhao, Y. L.; Li, F.; Wang, G. Y.; Zeng, F.; Pan, F.</p> <p>2014-10-01</p> <p>We investigate the effect of strain-<span class="hlt">induced</span> intrinsic <span class="hlt">exchange</span> bias field (HEB) on the magnetization rotation process in a nominally "single" layered La2/3Sr1/3MnO3 (LSMO) film. The intrinsic <span class="hlt">exchange</span> bias appears when the LSMO film is grown on LaAlO3 substrate. The HEB is proved to be an effective approach to tuning the in-plane magnetization rotation, producing a 360° instead of 180° periodicity in the anisotropic magnetoresistance curves measured in a low external magnetic field. The planar Hall effect curves are asymmetric when the in-plane magnetization rotate between two orthogonal axes of LSMO, helped or hindered by the HEB. Our study reveals that the HEB in but not limited to LSMO with phase separation exhibits an unprecedentedly two-dimensional effect rather than merely establishing a reference magnetization direction as achieved in ferromagnetic/antiferromagnetic bilayers, thus furthering the cognition of manipulating the magnetization orientation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24777198','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24777198"><span id="translatedtitle">High-temperature electromagnons in the magnetically <span class="hlt">induced</span> multiferroic cupric oxide driven by intersublattice <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jones, S P P; Gaw, S M; Doig, K I; Prabhakaran, D; Hétroy Wheeler, E M; Boothroyd, A T; Lloyd-Hughes, J</p> <p>2014-01-01</p> <p>Magnetically <span class="hlt">induced</span> ferroelectric multiferroics present an exciting new paradigm in the design of multifunctional materials, by intimately coupling magnetic and polar order. Magnetoelectricity creates a novel quasiparticle excitation--the electromagnon--at terahertz frequencies, with spectral signatures that unveil important spin interactions. To date, electromagnons have been discovered at low temperature (<70 K) and predominantly in rare-earth compounds such as RMnO3. Here we demonstrate using terahertz time-domain spectroscopy that intersublattice <span class="hlt">exchange</span> in the improper multiferroic cupric oxide (CuO) creates electromagnons at substantially elevated temperatures (213-230 K). Dynamic magnetoelectric coupling can therefore be achieved in materials, such as CuO, that exhibit minimal static cross-coupling. The electromagnon strength and energy track the static polarization, highlighting the importance of the underlying cycloidal spin structure. Polarized neutron scattering and terahertz spectroscopy identify a magnon in the antiferromagnetic ground state, with a temperature dependence that suggests a significant role for biquadratic <span class="hlt">exchange</span>. PMID:24777198</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JaJAP..55hNB07K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JaJAP..55hNB07K&link_type=ABSTRACT"><span id="translatedtitle">Surface-segregated Si and Ge ultrathin films formed by Ag-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurosawa, Masashi; Ohta, Akio; Araidai, Masaaki; Zaima, Shigeaki</p> <p>2016-08-01</p> <p>We have developed a new method of growing Si or Ge ultrathin films on a Ag(111) surface by using a Ag-<span class="hlt">induced</span> layer <span class="hlt">exchange</span> (ALEX) process toward the creation of 2D honeycomb sheets of Si and Ge, known as silicene and germanene, respectively. In the present paper, we clarify ALEX features, specifically the surface segregation of Si (or Ge) atoms from the underlying substrate, focusing on the annealing temperature and time. Hard X-ray photoelectron spectroscopy analyses demonstrate that surface-segregated Si (or Ge) exists on the Ag surfaces after the epitaxial growth of the Ag layer on Si(111) [or Ge(111)] substrates; the amount of segregated Si (or Ge) can be controlled by a subsequent annealing. Also, we find that the segregation of an ultrathin Si or Ge layer proceeds at an interface between Ag and the AlO x capping layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AcSpA..95..533V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AcSpA..95..533V"><span id="translatedtitle">Multivariate analysis of Ion Beam <span class="hlt">Induced</span> Luminescence spectra of irradiated silver ion-<span class="hlt">exchanged</span> silicate glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valotto, Gabrio; Quaranta, Alberto; Cattaruzza, Elti; Gonella, Francesco; Rampazzo, Giancarlo</p> <p></p> <p>A multivariate analysis is used for the identification of the spectral features in Ion Beam <span class="hlt">Induced</span> Luminescence (IBIL) spectra of soda-lime silicate glasses doped with silver by Ag+-Na+ ion <span class="hlt">exchange</span>. Both Principal Component Analysis and multivariate analysis were used to characterize time-evolving IBIL spectra of Ag-doped glasses, by means of the identification of the number and of the wavelength positions of the main luminescent features and the study of their evolution during irradiation. This method helps to identify the spectral features of the samples spectra, even when partially overlapped or less intense. This analysis procedure does not require additional input such as the number of peaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22571943','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22571943"><span id="translatedtitle">Multivariate analysis of Ion Beam <span class="hlt">Induced</span> Luminescence spectra of irradiated silver ion-<span class="hlt">exchanged</span> silicate glasses.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Valotto, Gabrio; Quaranta, Alberto; Cattaruzza, Elti; Gonella, Francesco; Rampazzo, Giancarlo</p> <p>2012-09-01</p> <p>A multivariate analysis is used for the identification of the spectral features in Ion Beam <span class="hlt">Induced</span> Luminescence (IBIL) spectra of soda-lime silicate glasses doped with silver by Ag(+)-Na(+) ion <span class="hlt">exchange</span>. Both Principal Component Analysis and multivariate analysis were used to characterize time-evolving IBIL spectra of Ag-doped glasses, by means of the identification of the number and of the wavelength positions of the main luminescent features and the study of their evolution during irradiation. This method helps to identify the spectral features of the samples spectra, even when partially overlapped or less intense. This analysis procedure does not require additional input such as the number of peaks. PMID:22571943</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23003184','PUBMED'); return false;" href="http://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="http://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. PMID:23003184</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150009494','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150009494"><span id="translatedtitle">Proximity Within Interphase Chromosome Contributes to the Breakpoint Distribution in Radiation-<span class="hlt">Induced</span> Intrachromosomal <span class="hlt">Exchanges</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu</p> <p>2015-01-01</p> <p>Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome3 in human mammary epithelial cells after exposures to either low-or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome <span class="hlt">exchange</span> event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-<span class="hlt">induced</span> chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome <span class="hlt">exchanges</span> involving breaks on the p-arm and in the centromere region of chromosome3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-<span class="hlt">induced</span> chromosome aberrations. Further investigations suggest that the 3D chromosome folding is cell type and culture condition dependent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16334295','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16334295"><span id="translatedtitle">Antigenotoxic effect of allicin against methyl methanesulphonate <span class="hlt">induced</span> genotoxic damage.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siddique, Yasir Hasan; Afzal, Mohammad</p> <p>2005-07-01</p> <p>Allicin, one of the sulfur compounds especially thiosulphonates of garlic (Allium sativum), possesses antioxidant and thioldisulphide <span class="hlt">exchange</span> activity and is also shown to cause a variety of actions potentially useful for human health. In this investigation we determined its antigenotoxic potential using chromosomal aberrations (CAs) and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) <span class="hlt">induced</span> by methyl methanesulphonate (MMS) as genotoxic end points both in the presence as well as absence of rat liver microsomal activation system (S9 mix) in cultured human lymphocytes. We tested the effect of 5, 10 and 20 microM of allicin on the damage exerted by 60 microM of MMS. The levels of CAs and SCEs were lowered suggesting an antigenotoxic role of allicin against genotoxic damage both in the presence as well as absence of metabolic activation. PMID:16334295</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1783675','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1783675"><span id="translatedtitle">Roles of the sister <span class="hlt">chromatid</span> cohesion apparatus in gene expression, development, and human syndromes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dorsett, Dale</p> <p>2006-01-01</p> <p>The sister <span class="hlt">chromatid</span> cohesion apparatus mediates physical pairing of duplicated chromosomes. This pairing is essential for appropriate distribution of chromosomes into the daughter cells upon cell division. Recent evidence shows that the cohesion apparatus, which is a significant structural component of chromosomes during interphase, also affects gene expression and development. The Cornelia de Lange (CdLS) and Roberts/SC phocomelia (RBS/SC) genetic syndromes in humans are caused by mutations affecting components of the cohesion apparatus. Studies in Drosophila suggest that effects on gene expression are most likely responsible for developmental alterations in CdLS. Effects on <span class="hlt">chromatid</span> cohesion are apparent in RBS/SC syndrome, but data from yeast and Drosophila point to the likelihood that changes in expression of genes located in heterochromatin could contribute to the developmental deficits. PMID:16819604</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1470669','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/15454308','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15454308"><span id="translatedtitle">Reduction of chrysotile asbestos-<span class="hlt">induced</span> genotoxicity in human peripheral blood lymphocytes by garlic extract.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bhattacharya, Kunal; Yadava, Santosh; Papp, Thilo; Schiffmann, Dietmar; Rahman, Qamar</p> <p>2004-11-28</p> <p>Asbestos fibers are well known environmental carcinogen, however, the underlying mechanisms of their action have still not clearly been identified. Asbestos is capable of depleting glutathione and generating reactive oxygen species (ROS), which are important mediators of damage in biological system. Asbestos-<span class="hlt">induced</span> mutagenecity, may be mediated by the generation. It is known that a number of scavengers and antioxidants attenuate asbestos-<span class="hlt">induced</span> ROS release. Furthermore, it is known that garlic, contains numerous sulfur compounds and glutathione precursors which act as antioxidants and also demonstrate anticarcinogenic properties. The aim of this study was to investigate whether garlic extract has any influence on asbestos-mediated genotoxicity. As an assay system, we applied the micronucleus assay, sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, and chromosomal aberrations with human peripheral blood lymphocytes, which has already been used to analyze the genotoxicity of asbestos fibers. Our results indicate that garlic extract, when administered to the lymphocytes cell culture simultaneously with chrysotile reduced the rates of micronucleus formation, sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, and chromosomal aberrations significantly. We conclude that garlic extract may be an efficient, physiologically tolerable quencher of asbestos-mediated genotoxicity. PMID:15454308</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2670183','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2670183"><span id="translatedtitle">Characterization of the components of the putative mammalian sister <span class="hlt">chromatid</span> cohesion complex</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Darwiche, N.; Freeman, L.A.; Strunnikov, A.</p> <p>2009-01-01</p> <p>Establishing and maintaining proper sister <span class="hlt">chromatid</span> cohesion throughout the cell cycle are essential for maintaining genome integrity. To understand how sister <span class="hlt">chromatid</span> cohesion occurs in mammals, we have cloned and characterized mouse orthologs of proteins known to be involved in sister <span class="hlt">chromatid</span> cohesion in other organisms. The cDNAs for the mouse orthologs of SMC1S.c. and SMC3S.c., mSMCB and mSMCD respectively, were cloned and the corresponding transcripts and proteins were characterized. mSMCB and mSMCD are transcribed at similar levels in adult mouse tissues except in testis, which has an excess of mSMCD transcripts. The mSMCB and mSMCD proteins, as well as the PW29 protein, a mouse homolog of Mcd1pS.c./Rad21S.p., form a complex similar to cohesin in X. laevis. mSMCB, mSMCD and PW29 protein levels show no significant cell-cycle dependence. The bulk of the mSMCB, mSMCD and PW29 proteins undergo redistribution from the chromosome vicinity to the cytoplasm during prometaphase and back to the chromatin in telophase. This pattern of intracellular localization suggests a complex role for this group of SMC proteins in chromosome dynamics. The PW29 protein and PCNA, which have both been implicated in sister <span class="hlt">chromatid</span> cohesion, do not colocalize, indicating that these proteins may not function in the same cohesion pathway. Overexpression of a PW29-GFP fusion protein in mouse fibroblasts leads to inhibition of proliferation, implicating this protein and its complex with SMC proteins in the control of mitotic cycle progression. PMID:10375619</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20582805','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20582805"><span id="translatedtitle">Antigenotoxic effect of allicin against estradiol-17beta-<span class="hlt">induced</span> genotoxic damage in cultured mammalian cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siddique, Yasir Hasan; Beg, Tanveer; Ara, Gulshan; Gupta, Jyoti; Afzal, Mohammad</p> <p>2010-07-01</p> <p>Antigenotoxic activity of allicin, one of the sulphur compounds of garlic (Allium sativum) which possesses antioxidant and thiol disulphide <span class="hlt">exchange</span> activity, was studied against estradiol-17beta-<span class="hlt">induced</span> genotoxic damage using chromosomal aberrations (CAs) and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) as parameters. Approximately 10, 20 and 40 microM of estradiol-17beta was tested for its genotoxic effect in the presence of metabolic activation and was found to be genotoxic at 20 and 40 microM. Approximately 20 microM of estradiol-17beta was treated along with 5, 10 and 15 microM of allicin, separately, in the presence of metabolic activation. Similar treatments were given with 40 microM of estradiol-17beta. Treatments along with allicin result in the reduction of CAs and SCEs, suggesting its anti-genotoxic activity in human lymphocytes in vitro against estradiol-17beta-<span class="hlt">induced</span> genotoxic damage. PMID:20582805</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18613199','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18613199"><span id="translatedtitle">Photo-<span class="hlt">induced</span> hydrogen <span class="hlt">exchange</span> reaction between methanol and glyoxal: formation of hydroxyketene.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mielke, Zofia; Mucha, Małgorzata; Bil, Andrzej; Golec, Barbara; Coussan, Stephane; Roubin, Pascale</p> <p>2008-08-25</p> <p>We study the structure and photochemistry of the glyoxal-methanol system (G-MeOH) by means of FTIR matrix isolation spectroscopy and ab initio calculations. The FTIR spectra show that the non-hydrogen-bonded complex, G-MeOH-1, is present in an inert environment of solid argon. MP2/aug-cc-pVDZ calculations indicate that G-MeOH-1 is the most stable complex among the five optimized structures. The interaction energy partitioned according to the symmetry-adapted perturbation theory (SAPT) scheme demonstrates that the dispersion energy gives a larger contribution to the stabilization of a non-hydrogen-bonded G-MeOH-1 complex than compared to the hydrogen-bonded ones. The irradiation of G-MeOH-1 with the filtered output of a mercury lamp (lambda>370 nm) leads to its photo-conversion into the hydroxyketene-methanol complex HK-MeOH-1. The identity of HK-MeOH-1 is confirmed by both FTIR spectroscopy and MP2/aug-cc-pVDZ calculations. An experiment with deuterated methanol (CH(3)OD) evidences that hydroxyketene is formed in a photo-<span class="hlt">induced</span> hydrogen <span class="hlt">exchange</span> reaction between glyoxal and methanol. The pathway for the photo-conversion of G-MeOH-1 to HK-MeOH-1 is studied by a coupled-cluster method [CR-CC(2,3)]. The calculations confirm our experimental findings that the reaction proceeds via hydrogen atom <span class="hlt">exchange</span> between the OH group of methanol and CH group of glyoxal. PMID:18613199</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.2923C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.2923C"><span id="translatedtitle">Three-dimensional versus two-dimensional bed form-<span class="hlt">induced</span> 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>Chen, Xiaobing; Cardenas, M. Bayani; Chen, Li</p> <p>2015-04-01</p> <p>The hyporheic zone is often a critical component of river systems. Hyporheic <span class="hlt">exchange</span> is generally forced by variation in riverbed topography such as due to bed forms. Most previous research on bed form-driven hyporheic flow has focused on two-dimensional (2-D) dunes and ripples, while little has been done on their three-dimensional (3-D) counterparts. Here we compared hyporheic <span class="hlt">exchange</span> and associated metrics for a previously studied pair of corresponding 2-D and 3-D bed forms. To accomplish this, a series of multiphysics computational fluid dynamics models were conducted both in 2-D and 3-D with similar open channel Reynolds numbers (Re). Results show that the pressure gradient along the sediment-water interface is highly sensitive to the spatial structure of bed forms, which consequently determines hyporheic flow dynamics. Hyporheic flux is a function of Re for both 2-D and 3-D dunes via a power law; however, the equivalent 3-D dunes have a higher flux since the 3-D form <span class="hlt">induces</span> more drag. The hyporheic zone depths and volumes are only slightly different with the 3-D case having a larger volume. The mean fluid residence times for both cases are related to Re by an inverse power law relationship, with the 3-D dune having smaller residence times at moderate to high Re. The effects of increasing flux on residence time in 3-D dunes are partly modulated by a slightly increasing hyporheic volume. Our results suggest that a 2-D idealization is a reasonable approximation for the more complex 3-D situation if local details are unimportant but that development of predictive models for mean fluxes and residence times, which are critical for biogeochemical processes, based on 2-D models may be insufficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3730250','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3730250"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bisht, Kamlesh K.; Daniloski, Zharko; Smith, Susan</p> <p>2013-01-01</p> <p>Summary 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. PMID:23729739</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23134723','PUBMED'); return false;" href="http://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="http://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. PMID:23134723</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1637748','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1637748"><span id="translatedtitle">Studies of negative ions by collision-<span class="hlt">induced</span> decomposition and hydrogen-deuterium <span class="hlt">exchange</span> techniques.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hunt, D F; Sethi, S K; Shabanowitz, J</p> <p>1980-01-01</p> <p>Development of two new techniques for studying the gas phase chemistry of negative ions is reported. Collision <span class="hlt">induced</span> dissociation (CID) of (M-1)- ions has been accomplished in a newly constructed triple stage quadrupole mass spectrometer. This instrument was assembled by adding two additional Finnigan quadrupole mass filters to a Finnigan Model 3200 CI mass spectrometer. Generation of (M-1)- ions is accomplished by allowing OH- and sample to react under CI conditions in the ion source. The first quadrupole mass filter, Q1, is then employed to selectively pass the (M-1)- ion into a second quadrupole filter containing argon or neon at 10(-3) torr. On collision with the inert gas the (M-1)- ions dissociate into fragments which are then mass analyzed in the third quadrupole filter, CID spectra of (M-1)- ions from twelve carbonyl compounds are presented in this paper. Ion molecule isotope <span class="hlt">exchange</span> reactions in the CI ion source can be used to count the number of hydrogen atoms in many different chemical environments. Collisions between sample (M-1)- ions and deuterium-labeled reagent gases (ND3, D2O, EtOD) facilitate incorporation of deuterium into the negative ion if the basicities of the sample and reagent anions are similar. Thus it is possible to selectively incorporate deuterium into many organic samples by controlling the exothermicity of the acid base, ion-molecule chemistry. PMID:7428745</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040088798&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddeuterium','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040088798&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddeuterium"><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('http://adsabs.harvard.edu/abs/2010AGUFMNH13B1151A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNH13B1151A"><span id="translatedtitle">Climate-<span class="hlt">induced</span> tree mortality: earth system consequences for carbon, energy, and water <span class="hlt">exchanges</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adams, H. D.; Macalady, A.; Breshears, D. D.; Allen, C. D.; Luce, C.; Royer, P. D.; Huxman, T. E.</p> <p>2010-12-01</p> <p> subsurface flow, runoff, groundwater recharge, and streamflow. Under some circumstances there may also be increased flood risks. We hypothesized thresholds of mean annual precipitation and canopy cover reduction identified from the forest harvesting literature as minima that must be exceeded for die-off to noticeably affect hydrologic processes. We note exceptions to these thresholds when snowmelt dominates the watershed hydrology and when mortality affects a single species with a unique hydrologic role. Management options for mitigating die-off effects on ecosystem and earth system processes and implementing post-die-off restoration will likely be limited and costly, requiring ecological and societal adaptation in many areas. As such, climate-<span class="hlt">induced</span> tree mortality poses a significant risk to the current earth system function through altered <span class="hlt">exchanges</span> of carbon, energy, and water between the land surface and atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/14598338','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/14598338"><span id="translatedtitle">Chromosome instability <span class="hlt">induced</span> in vitro with mitomycin C in five Seckel syndrome patients.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bobabilla-Morales, Lucina; Corona-Rivera, Alfredo; Corona-Rivera, J Román; Buenrostro, C; García-Cobián, Teresa A; Corona-Rivera, Enrique; Cantú-Garza, José María; García-Cruz, Diana</p> <p>2003-12-01</p> <p>Seckel syndrome (SS) is an autosomal recessive entity characterized by proportionate pre- and post-natal growth retardation, microcephaly, typical facial appearance with beak-like protrusion, and severe mental retardation. A heterogeneous basis for SS was proposed since around 25% of SS patients have hematological anomalies, suggesting a subgroup of SS with chromosome instability and hematological disorders. Chromosome instability <span class="hlt">induced</span> by mitomycin C (MMC) has been observed in previous reports. The purpose of this study is to report cytogenetic features in five patients with SS. The patients had low birth weight (mean 1,870 g), short stature (SD = 6.36), microcephaly (OFC, SD = 8.1), typical facial appearance, and multiple articular dislocations. None of them had anemia at the time of examination. In all cases their parents were healthy and non-consanguineous. Lymphocytes of SS patients and a control group (n = 9) matched by age and sex were cultured with and without MMC, and harvested at 72 and 96 hr. Chromosomal aberrations (<span class="hlt">chromatid</span> and chromosomal gaps and breaks, deletions, fragments, and <span class="hlt">exchanges</span>) were scored in 100 metaphases per culture. A statistical increase of chromosomal aberrations was observed in 96 hr MMC cultures in all patients (40.2% vs. 2.8%). Sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> were also performed with no differences between groups. Clinical and cytogenetic findings support the idea that SS may correspond to a chromosome instability syndrome. PMID:14598338</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3424243','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3424243"><span id="translatedtitle">LAB-1 Targets PP1 and Restricts Aurora B Kinase upon Entrance into Meiosis to Promote Sister <span class="hlt">Chromatid</span> Cohesion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tzur, Yonatan B.; Egydio de Carvalho, Carlos; Nadarajan, Saravanapriah; Van Bostelen, Ivo; Gu, Yanjie; Chu, Diana S.; Cheeseman, Iain M.; Colaiácovo, Monica P.</p> <p>2012-01-01</p> <p>Successful execution of the meiotic program depends on the timely establishment and removal of sister <span class="hlt">chromatid</span> cohesion. LAB-1 has been proposed to act in the latter by preventing the premature removal of the meiosis-specific cohesin REC-8 at metaphase I in C. elegans, yet the mechanism and scope of LAB-1 function remained unknown. Here we identify an unexpected earlier role for LAB-1 in promoting the establishment of sister <span class="hlt">chromatid</span> cohesion in prophase I. LAB-1 and REC-8 are both required for the chromosomal association of the cohesin complex subunit SMC-3. Depletion of lab-1 results in partial loss of sister <span class="hlt">chromatid</span> cohesion in rec-8 and coh-4 coh-3 mutants and further enhanced <span class="hlt">chromatid</span> dissociation in worms where all three kleisins are mutated. Moreover, lab-1 depletion results in increased Aurora B kinase (AIR-2) signals in early prophase I nuclei, coupled with a parallel decrease in signals for the PP1 homolog, GSP-2. Finally, LAB-1 directly interacts with GSP-1 and GSP-2. We propose that LAB-1 targets the PP1 homologs to the chromatin at the onset of meiosis I, thereby antagonizing AIR-2 and cooperating with the cohesin complex to promote sister <span class="hlt">chromatid</span> association and normal progression of the meiotic program. PMID:22927794</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=dna+metabolism&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddna%2Bmetabolism','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040088722&hterms=dna+metabolism&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddna%2Bmetabolism"><span id="translatedtitle">Probabilities of radiation-<span class="hlt">induced</span> inter- and intrachromosomal <span class="hlt">exchanges</span> and their dependence on the DNA content of the chromosome</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, H.; Yang, T. C. (Principal Investigator)</p> <p>2001-01-01</p> <p>A biophysical model has been developed that is based on the assumptions that an interphase chromosome occupies a spherical territory and that chromosome <span class="hlt">exchanges</span> are formed by the misrejoining of two DNA double-strand breaks <span class="hlt">induced</span> within a defined interaction distance. The model is used to explain the relative frequencies of inter- and intrachromosomal <span class="hlt">exchanges</span> and the relationship between radiation-<span class="hlt">induced</span> aberrations in individual chromosomes and the DNA content of the chromosome. Although this simple model predicts a higher ratio of inter- to intrachromosomal <span class="hlt">exchanges</span> for low-LET radiation than for high-LET radiation, as has been suggested by others, we argue that the comparison of the prediction of the model with experimental results is not straightforward. With the model, we also show that the probability of the formation of interchromosomal <span class="hlt">exchanges</span> is proportional to the "surface area" of the chromosome domain plus a correction term. The correction term is small if the interaction distance is less than 1 microm for both low- and high-LET radiations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16802858','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16802858"><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=pubmed">PubMed</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; Strachan, Tom</p> <p>2006-07-01</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1484498','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/26697498','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26697498"><span id="translatedtitle">Inhibition of NA(+)/H(+) <span class="hlt">Exchanger</span> 1 Attenuates Renal Dysfunction <span class="hlt">Induced</span> by Advanced Glycation End Products in Rats.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Peng; Chen, Geng-Rong; Wang, Fu; Xu, Ping; Liu, Li-Ying; Yin, Ya-Ling; Wang, Shuang-Xi</p> <p>2016-01-01</p> <p>It has been recognized that sodium hydrogen <span class="hlt">exchanger</span> 1 (NHE1) is involved in the development of diabetic nephropathy. The role of NHE1 in kidney dysfunction <span class="hlt">induced</span> by advanced glycation end products (AGEs) remains unknown. Renal damage was <span class="hlt">induced</span> by AGEs via tail vein injections in rats. Function and morphology of kidney were determined. Compared to vehicle- or BSA-treated rats, AGEs caused abnormalities of kidney structures and functions in rats, accompanied with higher MDA level and lower GSH content. Gene expressions of NHE1 gene and TGF-β1 in the renal cortex and urine were also increased in AGEs-injected rats. Importantly, all these detrimental effects <span class="hlt">induced</span> by AGEs were reversed by inhibition of NHE1 or suppression of oxidative stress. These pieces of data demonstrated that AGEs may activate NHE1 to <span class="hlt">induce</span> renal damage, which is related to TGF-β1. PMID:26697498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838874','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/27098292','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27098292"><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=pubmed">PubMed</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 Ln(3+) complexes. PMID:27098292</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25337657','PUBMED'); return false;" href="http://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="http://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. PMID:25337657</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27389420','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27389420"><span id="translatedtitle">Water-<span class="hlt">Induced</span> Decoupling of Tracer and Electrochemical Oxygen <span class="hlt">Exchange</span> Kinetics on Mixed Conducting Electrodes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nenning, Andreas; Navickas, Edvinas; Hutter, Herbert; Fleig, Jürgen</p> <p>2016-07-21</p> <p>Isotope <span class="hlt">exchange</span> depth profiling and electrochemical impedance spectroscopy are usually regarded as complementary tools for measuring the surface oxygen <span class="hlt">exchange</span> activity of mixed conducting oxides, for example used in solid oxide fuel cell (SOFC) electrodes. Only very few studies compared electrical (k(q)) and tracer (k*) <span class="hlt">exchange</span> coefficients of solid-gas interfaces measured under identical conditions. The 1:1 correlation between k(q) and k* often made is thus more an assumption than experimentally verified. In this study it is shown that the measured rates of electrical and tracer <span class="hlt">exchange</span> of oxygen may strongly differ. Simultaneous acquisition of k(q) and k* on La0.6Sr0.4FeO3-δ and SrTi0.3Fe0.7O3-δ thin film electrodes revealed that k* > 100 k(q) in humid oxidizing ((16)O2 + H2(18)O) and humid reducing (H2 + H2(18)O) atmospheres. These results are explained by fast water adsorption and dissociation on surface oxygen vacancies, forming two surface hydroxyl groups. Hence, interpreting experimentally determined k* values in terms of electrochemically relevant oxygen <span class="hlt">exchange</span> is not straightforward. PMID:27389420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25946564','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25946564"><span id="translatedtitle">The SUMO deconjugating peptidase Smt4 contributes to the mechanism required for transition from sister <span class="hlt">chromatid</span> arm cohesion to sister <span class="hlt">chromatid</span> pericentromere separation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stephens, Andrew D; Snider, Chloe E; Bloom, Kerry</p> <p>2015-01-01</p> <p>The pericentromere chromatin protrudes orthogonally from the sister-sister chromosome arm axis. Pericentric protrusions are organized in a series of loops with the centromere at the apex, maximizing its ability to interact with stochastically growing and shortening kinetochore microtubules. Each pericentromere loop is ∼50 kb in size and is organized further into secondary loops that are displaced from the primary spindle axis. Cohesin and condensin are integral to mechanisms of loop formation and generating resistance to outward forces from kinesin motors and anti-parallel spindle microtubules. A major unanswered question is how the boundary between chromosome arms and the pericentromere is established and maintained. We used sister <span class="hlt">chromatid</span> separation and dynamics of LacO arrays distal to the pericentromere to address this issue. Perturbation of chromatin spring components results in 2 distinct phenotypes. In cohesin and condensin mutants sister pericentric LacO arrays separate a defined distance independent of spindle length. In the absence of Smt4, a peptidase that removes SUMO modifications from proteins, pericentric LacO arrays separate in proportion to spindle length increase. Deletion of Smt4, unlike depletion of cohesin and condensin, causes stretching of both proximal and distal pericentromere LacO arrays. The data suggest that the sumoylation state of chromatin topology adjusters, including cohesin, condensin, and topoisomerase II in the pericentromere, contribute to chromatin spring properties as well as the sister cohesion boundary. PMID:25946564</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/2011PlST...13..604L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PlST...13..604L"><span id="translatedtitle">Plasma-<span class="hlt">induced</span> Styrene Grafting onto the Surface of Polytetrafluoroethylene Powder for Proton <span class="hlt">Exchange</span> Membrane Application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lan, Yan; Cheng, Cheng; Zhang, Suzhen; Ni, Guohua; Chen, Longwei; Yang, Guangjie; Nagatsu, M.; Meng, Yuedong</p> <p>2011-10-01</p> <p>Low-temperature plasma treatment was adopted to graft styrene onto polytetrafluoroethylene (PTFE) powder, which is widely used in the fabrication of proton <span class="hlt">exchange</span> membrane (PEM). The grafted PTFE powder was sulfonated in chlorosulfonic acid and fabricated into a membrane, which was used as inexpensive PEM material for a proton <span class="hlt">exchange</span> membrane fuel cell (PEMFC). Fourier transform infrared spectroscopy attenuated total reflection spectroscopy (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) analysis were used to characterize the structure of the sulfonated PTFE powder. The results showed that all the PTFE powders were successfully grafted by nitrogen plasma and then sulfonated under such experimental conditions. A scanning electron microscopy (SEM) image indicated that the fabricated membrane exhibits flat morphology and homogenous structure. The ion <span class="hlt">exchange</span> capacity (IEC) of this kind of PEM was also investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.108s2402L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.108s2402L"><span id="translatedtitle"><span class="hlt">Exchange</span> magnon <span class="hlt">induced</span> resistance asymmetry in permalloy spin-Hall oscillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langenfeld, S.; Tshitoyan, V.; Fang, Z.; Wells, A.; Moore, T. A.; Ferguson, A. J.</p> <p>2016-05-01</p> <p>We investigate magnetization dynamics in a spin-Hall oscillator using a direct current measurement as well as conventional microwave spectrum analysis. When the current applies an anti-damping spin-transfer torque, we observe a change in resistance which we ascribe mainly to the excitation of incoherent <span class="hlt">exchange</span> magnons. A simple model is developed based on the reduction of the effective saturation magnetization, quantitatively explaining the data. The observed phenomena highlight the importance of <span class="hlt">exchange</span> magnons on the operation of spin-Hall oscillators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16719949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16719949"><span id="translatedtitle">Na+ /Ca2+ <span class="hlt">exchanger</span> contributes to asterosap-<span class="hlt">induced</span> elevation of intracellular Ca2+ concentration in starfish spermatozoa.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Islam, M Sadiqul; Kawase, Osamu; Hase, Sumitaka; Minakata, Hiroyuki; Hoshi, Motonori; Matsumoto, Midori</p> <p>2006-05-01</p> <p>Asterosap, a group of equally active isoforms of sperm-activating peptides from the egg jelly of the starfish Asterias amurensis, functions as a chemotactic factor for sperm. It transiently increases the intracellular cGMP level of sperm, which in turn <span class="hlt">induces</span> a transient elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)). Using a fluorescent Ca(2+)-sensitive dye, Fluo-4 AM, we measured the changes in sperm [Ca(2+)](i) in response to asterosap. KB-R7943 (KB), a selective inhibitor of Na(+)/Ca(2+) <span class="hlt">exchanger</span> (NCX), significantly inhibited the asterosap-<span class="hlt">induced</span> transient elevation of [Ca(2+)](i), suggesting that asterosap influences [Ca(2+)](i) through activation of a K+-dependent NCX (NCKX). An NCKX activity of starfish sperm also shows K(+) dependency like other NCKXs. Therefore, we cloned an NCKX from the starfish testes and predicted that it codes for a 616 amino acid protein that is a member of the NCKX family. Pharmacological evidence suggests that this <span class="hlt">exchanger</span> participates in the asterosap-<span class="hlt">induced</span> Ca(2+) entry into sperm. PMID:16719949</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApSS..367..418Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApSS..367..418Z"><span id="translatedtitle">Fast laser annealing <span class="hlt">induced</span> <span class="hlt">exchange</span> bias in poly-crystalline BiFeO3/Co bilayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y. Q.; Ruan, X. Z.; Liu, B.; Xu, Z. Y.; Xu, Q. Y.; Shen, J. D.; Li, Q.; Wang, J.; You, B.; Tu, H. Q.; Gao, Y.; Zhang, W.; Xu, Y. B.; Du, J.</p> <p>2016-03-01</p> <p>The conventional field cooling process for antiferromagnetic/ferromagnetic bilayer system might strongly damage the interface of BiFeO3 (BFO) with metallic ferromagnetic layer, leading to significant deterioration of <span class="hlt">exchange</span> bias (EB). In this paper, a field cooling process with fast laser annealing has been proposed and applied on polycrystalline-BFO/Co bilayers, which can effectively modify the EB. In those samples with obvious EB, it is found that the <span class="hlt">exchange</span> field (HE) increases abruptly when the laser fluence rises to a critical value, and decreases when the laser fluence is large enough. On the other hand, in those samples with negligible HE, EB could be easily <span class="hlt">induced</span> after field cooling with proper laser fluence. In addition, the sign of HE could also be changed, depending on the direction of the cooling field. In contrast, after field cooling by conventional heat treatment, EB could be neither <span class="hlt">induced</span> nor enhanced. The feasibility of fast laser annealing accompanied with field cooling to enhance or <span class="hlt">induce</span> EB in the BFO/Co bilayer can be understood by much less interfacial diffusion in comparison with conventional field cooling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25378216','PUBMED'); return false;" href="http://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="http://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. PMID:25378216</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467855','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467855"><span id="translatedtitle">Phosphorylation of the <span class="hlt">exchange</span> factor DENND3 by ULK in response to starvation activates Rab12 and <span class="hlt">induces</span> autophagy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Jie; Fotouhi, Maryam; McPherson, Peter S</p> <p>2015-01-01</p> <p>Unc-51-like kinases (ULKs) are the most upstream kinases in the initiation of autophagy, yet the molecular mechanisms underlying their function are poorly understood. We report a new role for ULK in the induction of autophagy. ULK-mediated phosphorylation of the guanine nucleotide <span class="hlt">exchange</span> factor DENND3 at serines 554 and 572 upregulates its GEF activity toward the small GTPase Rab12. Through binding to LC3 and associating with LC3-positive autophagosomes, active Rab12 facilitates autophagosome trafficking, thus establishing a crucial role for the ULK/DENND3/Rab12 axis in starvation-<span class="hlt">induced</span> autophagy. PMID:25925668</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21596540','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21596540"><span id="translatedtitle">Synthesis of N=127 isotones through (p,n) charge-<span class="hlt">exchange</span> reactions <span class="hlt">induced</span> by relativistic {sup 208}Pb projectiles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morales, A. I.; Benlliure, J.; Alvarez-Pol, H.; Casarejos, E.; Dragosavac, D.; Perez-Loureiro, D.; Verma, S.; Agramunt, J.; Molina, F.; Rubio, B.; Algora, A.; Alkhomashi, N.; Farrelly, G.; Gelletly, W.; Pietri, S.; Podolyak, Z.; Regan, P. H.; Steer, S. J.; Boutachkov, P.; Caceres, L. S.</p> <p>2011-07-15</p> <p>The production cross sections of four N=127 isotones ({sup 207}Hg, {sup 206}Au, {sup 205}Pt, and {sup 204}Ir) have been measured using (p,n) charge-<span class="hlt">exchange</span> reactions, <span class="hlt">induced</span> in collisions of a {sup 208}Pb primary beam at 1 A GeV with a Be target. These data allow one to investigate the use of a reaction mechanism to extend the limits of the chart of nuclides toward the important r-process nuclei in the region of the third peak of elemental abundance distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510348S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510348S"><span id="translatedtitle">Light-<span class="hlt">induced</span> diurnal pattern of methane <span class="hlt">exchange</span> in a boreal forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sundqvist, Elin; Crill, Patrick; Mölder, Meelis; Vestin, Patrik; Lindroth, Anders</p> <p>2013-04-01</p> <p>Boreal forests represents one third of the Earth's forested land surface area and is a net sink of methane and an important component of the atmospheric methane budget. Methane is oxidized in well-aerated forest soils whereas ponds and bog soils are sources of methane. Besides the microbial processes in the soil also forest vegetation might contribute to methane <span class="hlt">exchange</span>. Due to a recent finding of methane consumption by boreal plants that correlated with photosynthetic active radiation (PAR), we investigate the impact of PAR on soil methane <span class="hlt">exchange</span> at vegetated plots on the forest floor. The study site, Norunda in central Sweden, is a 120 years old boreal forest stand, dominated by Scots pine and Norway spruce. We used continuous chamber measurements in combination with a high precision laser gas analyzer (Los Gatos Research), to measure the methane <span class="hlt">exchange</span> at four different plots in July-November 2009, and April-June 2010. The ground vegetation consisted almost entirely of mosses and blueberry-shrubs. Two of the plots acted as stable sinks of methane whereas the other two plots shifted from sinks to sources during very wet periods. The preliminary results show a clear diurnal pattern of the methane <span class="hlt">exchange</span> during the growing season, which cannot be explained by temperature. The highest consumption occurs at high PAR levels. The amplitude of the diurnal methane <span class="hlt">exchange</span> during the growing season is in the order of 10 μmol m-2 h-1. This indicates that besides methane oxidation by methanotrophs in the soil there is an additional removal of methane at soil level by a process related to ground vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AnGeo..21.1289F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AnGeo..21.1289F"><span id="translatedtitle">The charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> coupling between plasma-gas counterflows in the heliosheath</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fahr, H. J.</p> <p>2003-06-01</p> <p>Many hydrodynamic models have been presented which give similar views of the interaction of the solar wind plasma bubble with the counterstreaming partially ionized interstellar medium. In the more recent of these models it is taken into account that the solar and interstellar hydrodynamic flows of neutral atoms and protons are coupled by mass-, momentum-, and energy-<span class="hlt">exchange</span> terms due to charge <span class="hlt">exchange</span> processes. We shall reinvestigate the theoretical basis of this coupling here by use of a simplified description of the heliospheric interface and describe the main physics of the H-atom penetration through the more or less standing well-known plasma wall ahead of the heliopause. Thereby we can show that the type of charge <span class="hlt">exchange</span> coupling terms used in up-to-now hydrodynamic treatments unavoidably leads to an O-type critical point at the sonic point of the H-atom flow, thus not allowing for a continuation of the integration of the hydrodynamic set of differential equations. The remedy for this problem is given by a more accurate formulation of the momentum <span class="hlt">exchange</span> term for quasi-and sub-sonic H-atom flows. With a refined momentum <span class="hlt">exchange</span> term derived from basic kinetic Boltzmann principles, we instead arrive at a characteristic equation with an X-type critical point, allowing for a continuous solution from supersonic to subsonic flow conditions. This necessitates that the often treated problem of the propagation of inter-stellar H-atoms through the heliosheath has to be solved using these newly derived, differently effective plasma - gas friction forces. Substantially different results are to be expected from this context for the filtration efficiency of the heliospheric interface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3872193','PMC'); return false;" href="http://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('http://www.osti.gov/scitech/biblio/20991421','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20991421"><span id="translatedtitle">Elimination of radiation-<span class="hlt">induced</span> {gamma}-H2AX foci in mammalian nucleus can occur by histone <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Svetlova, Maria; Solovjeva, Liudmila; Nishi, Kayoko; Nazarov, Igor; Siino, Joseph; Tomilin, Nikolai . E-mail: nvtom@mail.ru</p> <p>2007-06-29</p> <p>Double-strand breaks in mammalian DNA lead to rapid phosphorylation of C-terminal serines in histone H2AX ({gamma}-H2AX) and formation of large nuclear {gamma}-H2AX foci. After DNA repair these foci disappear, but molecular mechanism of elimination of {gamma}-H2AX foci remains unclear. H2AX protein can be phosphorylated and dephosphorylated in vitro in the absence of chromatin. Here, we compared global <span class="hlt">exchange</span> of GFP-H2AX with kinetics of formation and elimination of radiation-<span class="hlt">induced</span> {gamma}-H2AX foci. Maximal number of {gamma}-H2AX foci is observed one hour after irradiation, when {approx}20% of GFP-H2AX is <span class="hlt">exchanged</span> suggesting that formation of the foci mostly occurs by in situ H2AX phosphorylation. However, slow elimination of {gamma}-H2AX foci is weakly affected by an inhibitor of protein phosphatases calyculin A which is known as an agent suppressing dephosphorylation of {gamma}-H2AX. This indicates that elimination of {gamma}-H2AX foci may be independent of dephosphorylation of H2AX which can occur after its removal from the foci by <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=human+genomics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dhuman%2Bgenomics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100015501&hterms=human+genomics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dhuman%2Bgenomics"><span id="translatedtitle">Distributions of Low- and High-LET Radiation-<span class="hlt">Induced</span> Breaks in Chromosomes are Associated with Inter- and Intrachromosome <span class="hlt">Exchanges</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hada, Megumi; Zhang, Ye; Feiveson, Alan; Cucinotta, Francis A.; Wu, Honglu</p> <p>2010-01-01</p> <p>To study the breakpoint along the length of the chromosome <span class="hlt">induced</span> by low- and high-LET radiations, we exposed human epithelial cells in vitro to Cs-137 rays at both low and high dose rates, secondary neutrons at a low dose rate, and 600 MeV/u Fe ions at a high dose rate. The location of the breaks was identified using the multicolor banding in situ hybridization (mBAND) that paints Chromosome 3 in 23 different colored bands. The breakpoint distributions were found to be similar between rays of low and high dose rates and between the two high-LET radiation types. Detailed analysis of the chromosome break ends involved in inter- and intrachromosome <span class="hlt">exchanges</span> revealed that only the break ends participating in interchromosome <span class="hlt">exchanges</span> contributed to the hot spots found for low-LET. For break ends participating in intrachromosome <span class="hlt">exchanges</span>, the distributions for all four radiation scenarios were similar with clusters of breaks found in three regions. Analysis of the locations of the two break ends in Chromosome 3 that joined to form an intrachromosome <span class="hlt">exchange</span> demonstrated that two breaks with a greater genomic separation may be more likely to rejoin than two closer breaks, indicating that chromatin folding can play an important role in the rejoining of chromosome breaks. Our study demonstrated that the gene-rich regions do not necessarily contain more breaks. The breakpoint distribution depends more on the likelihood that a break will join with another break in the same chromosome or in a different chromosome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.2266Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.2266Z"><span id="translatedtitle">Correlation Between Interphase Chromatin Structure and - and High-Let Radiation-<span class="hlt">Induced</span> - and Intra-Chromosome <span class="hlt">Exchange</span> Hotspots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ye; Wu, Honglu; Mangala, Lingegowda; Asaithamby, Aroumougame; Chen, David</p> <p>2012-07-01</p> <p>CORRELATION BETWEEN INTERPHASE CHROMATIN STRUCTURE AND LOW- AND HIGH-LET RADIATION-<span class="hlt">INDUCED</span> INTER- AND INTRA-CHROMOSOME <span class="hlt">EXCHANGE</span> HOTSPOTS Ye Zhang1,2, Lingegowda S. Mangala1,3, Aroumougame Asaithamby4, David J. Chen4, and Honglu Wu1 1 NASA Johnson Space Center, Houston, Texas, USA 2 Wyle Integrated Science and Engineering Group, Houston, Texas, USA 3 University of Houston Clear Lake, Houston, Texas, USA 4 University of Texas, Southwestern Medical Center, Dallas, Texas, USA To investigate the relationship between chromosome aberrations <span class="hlt">induced</span> by low- and high-LET radiation and chromatin folding, we reconstructed the three dimensional structure of chromosome 3 and measured the physical distances between different regions of this chromosome. Previously, we investigated the location of breaks involved in inter- and intrachromosomal type <span class="hlt">exchange</span> events in chromosome 3 of human epithelial cells, using the multicolor banding in situ hybridization (mBAND) technique. After exposure to both low- and high-LET radiations in vitro, intra-chromosome <span class="hlt">exchanges</span> occurred preferentially between a break in the 3p21 and one in the 3q11 regions, and the breaks involved in inter-chromosome <span class="hlt">exchanges</span> occurred in two regions near the telomeres of the chromosome. In this study, human epithelial cells were fixed in G1 phase and interphase chromosomes hybridized with an mBAND probe for chromosome 3 were captured with a laser scanning confocal microscope. The 3-dimensional structure of interphase chromosome 3 with different colored regions was reconstructed, and the distance between different regions was measured. We show that, in most of the G1 cells, the regions containing 3p21 and 3q11 are colocalized in the center of the chromosome domain, whereas, the regions towards the telomeres of the chromosome are located in the peripherals of the chromosome domain. Our results demonstrate that the distribution of breaks involved in radiation-<span class="hlt">induced</span> inter and intra-chromosome aberrations depends</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25633096','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25633096"><span id="translatedtitle">NCX1 <span class="hlt">Exchanger</span> Cooperates with Calretinin to Confer Preconditioning-<span class="hlt">Induced</span> Tolerance Against Cerebral Ischemia in the Striatum.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boscia, Francesca; Casamassa, Antonella; Secondo, Agnese; Esposito, Alba; Pannaccione, Anna; Sirabella, Rossana; Pignataro, Giuseppe; Cuomo, Ornella; Vinciguerra, Antonio; de Rosa, Valeria; Annunziato, Lucio</p> <p>2016-03-01</p> <p>Recently, the Na(+)/Ca(+2) <span class="hlt">exchanger</span> NCX1 and the calcium binding protein calretinin have emerged as new molecular effectors of delayed preconditioning in the brain. In the present study, we investigated whether NCX1 and calretinin cooperate within the preconditioned striatum to confer neurons greater resistance to degeneration. Confocal microscopy analysis revealed that NCX1 expression was upregulated in calretinin-positive interneurons in the rat striatum after tolerance induction. Consistently, coimmunoprecipitation assays performed on human SHSY-5Y cells, a neuronal cell line which constitutively expresses calretinin, revealed a binding between NCX1 and calretinin. Finally, silencing of calretinin expression, both in vitro and in vivo, significantly prevented preconditioning-<span class="hlt">induced</span> neuroprotection. Interestingly, our biochemical and functional studies showed that the selective silencing of calretinin in brain cells significantly prevented not only the preconditioning-<span class="hlt">induced</span> upregulation of NCX1 expression and activity but also the activation of the prosurvival protein kinase Akt, which is involved in calretinin and NCX1 protective actions. Collectively, our results indicate that the Na(+)/Ca(+2) <span class="hlt">exchanger</span> NCX1 and the calcium binding protein calretinin cooperate within the striatum to confer tolerance against cerebral ischemia. PMID:25633096</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H31B0595C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H31B0595C"><span id="translatedtitle">Analysis of three-dimensional versus two-dimensional bedform-<span class="hlt">induced</span> 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>Chen, X.; Cardenas, M. B.; Chen, L.</p> <p>2014-12-01</p> <p>The hyporheic zone is a critical ecotone for maintaining the health of river systems due to the <span class="hlt">exchange</span> of water and nutrients between streams and groundwater. Within riverbeds, hyporheic <span class="hlt">exchange</span> is generally forced by variation in riverbed topography such as due to bedforms. In the past, a vast majority of research on bedform-driven hyporheic flow has focused on two-dimensional (2D) scenarios, while little has been done on more realistic three-dimensional (3D) situations. We investigated hyporheic <span class="hlt">exchanged</span> using a sinuous-crested 3D dune which is superimposed with successive crest lines of 2D dunes, and compared it to a 2D dune with similar wavelength and height. These 2D and 3D dunes are depicted in detail in McLean (1997) and Maddux (2003), respectively. A series of modeling studies are conducted both in 2D and 3D with similar open channel Reynolds numbers (Re). Turbulent flow in the water column is simulated by solving the Reynolds-averaged Navier-Stokes equations with the k-ω turbulence closure model, and a Darcy flow model is applied for the underlying porous media. These two sets of equations are coupled via the pressure distribution on the sediment-water interface (SWI). Results show that the pressure gradient along the SWI is highly controlled by the spatial structure of bedforms, which consequently determines flow dynamics in the porous media. Hyporheic flux is a function of Re for both 2D and 3D via a power-law trend; however, the hyporheic flux in the 3D dunes is generally higher and much more sensitive to Re. The depth and volume of the interfacial <span class="hlt">exchange</span> zone of the 3D-bedform driven flow are only slightly different from the 2D situation, showing that the dimensionality of bedform has less impact on the <span class="hlt">exchanged</span> zone. The mean fluid residence times for both 3D/2D dunes are related to Re by an inverse-power law relationship, they are different at low Re and become similar at higher Re. A 2D idealization seems a reasonable approximation for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6709721','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6709721"><span id="translatedtitle">Implications of S-phase <span class="hlt">exchanges</span> for the mechanisms of radiosensitivity in trisomy 21</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Athanasiou, K.; Bartsocas, C.S.</p> <p>1982-06-01</p> <p>Human lymphocytes obtained from four patients with Down syndrome and from two normal individuals were irradiated with X-rays during their S phase and examined for <span class="hlt">chromatid</span> type aberrations. It is suggested that the significantly increased frequency of asymmetrical <span class="hlt">chromatid</span> interchanges found in trisomic cells is related to an altered DNA repair system. This altered repair system is probably responsible for the increased frequency of chromosome aberrations that can be <span class="hlt">induced</span> in these cells by x-rays and the increased tendency for leukemia observed in Down syndrome as well.</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/cgi-bin/nph-data_query?bibcode=2001AdSpR..27..383K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001AdSpR..27..383K&link_type=ABSTRACT"><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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267994','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267994"><span id="translatedtitle">Involvement of the Sodium-Calcium <span class="hlt">exchanger</span> 3 (NCX3) in ziram-<span class="hlt">induced</span> calcium dysregulation and toxicity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jin, J.; Lao, A.J.; Katsura, M.; Caputo, A.; Schweizer, F. E.; Sokolow, S.</p> <p>2014-01-01</p> <p>Ziram is a dimethyldithiocarbamate fungicide which can cause intraneuronal calcium (Ca2+) dysregulation and subsequently neuronal death. The signaling mechanisms underlying ziram-<span class="hlt">induced</span> Ca2+ dyshomeostasis and neurotoxicity are not fully understood. NCX3 is the third isoform of the sodium-calcium <span class="hlt">exchanger</span> (NCX) family and plays an important role in regulating Ca2+ homeostasis in excitable cells. We previously generated a mouse model deficient for the sodium-calcium <span class="hlt">exchanger</span> 3 and showed that NCX3 is protective against ischemic damage. In the present study, we aim to examine whether NCX3 exerts a similar role against toxicological injury caused by the pesticide ziram. Our data show baby hamster kidney (BHK) cells stably transfected with NCX3 (BHK-NCX3) are more susceptible to ziram toxicity than cells transfected with the empty vector (BHK-WT). Increased toxicity in BHK-NCX3 was associated with a rapid rise in cytosolic Ca2+ concentration [Ca2+i] <span class="hlt">induced</span> by ziram. Profound mitochondrial dysfunction and ATP depletion were also observed in BHK-NCX3 cells following treatment with ziram. Lastly, primary dopaminergic neurons lacking NCX3 (NCX3−/−) were less sensitive to ziram neurotoxicity than wildtype control dopaminergic neurons. These results demonstrate that NCX3 genetic deletion protects against ziram-<span class="hlt">induced</span> neurotoxicity and suggest NCX3 and its downstream molecular pathways as key factors involved in ziram toxicity. Our study identifies new molecular events through which pesticides (e.g. ziram) can lead to pathological features of degenerative diseases such as Parkinson’s disease and indicates new targets to slow down neuronal degeneration. PMID:25284465</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24844246','PUBMED'); return false;" href="http://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="http://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>2014-01-01</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. PMID:24844246</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4054777','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4054777"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</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>2014-01-01</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 PMID:24844246</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995NIMPB..96..382C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995NIMPB..96..382C&link_type=ABSTRACT"><span id="translatedtitle">Irradiation-<span class="hlt">induced</span> Ag-colloid formation in ion-<span class="hlt">exchanged</span> soda-lime glass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caccavale, F.; De Marchi, G.; Gonella, F.; Mazzoldi, P.; Meneghini, C.; Quaranta, A.; Arnold, G. W.; Battaglin, G.; Mattei, G.</p> <p>1995-03-01</p> <p>Ion-<span class="hlt">exchanged</span> glass samples were obtained by immersing soda-lime slides in molten salt baths of molar concentration in the range 1-20% AgNO 3 in NaNO 3, at temperatures varying from 320 to 350°C, and processing times of the order of a few minutes. Irradiations of <span class="hlt">exchanged</span> samples were subsequently performed by using H +m, He +, N + ions at different energies in order to obtain comparable projected ranges. The fluence was varied between 5 × 10 15 and 2 × 10 17 ions/cm 2. Most of the samples were treated at current densities lower than 2 μA/cm 2, in order to avoid heating effects. Some samples were irradiated with 4 keV electrons, corresponding to a range of 250 nm. The formation of nanoclusters of radii in the range 1-10 nm has been observed after irradiation, depending on the treatment conditions. The precipitation process is governed by the electronic energy deposition of incident particles. The most desirable results are obtained for helium implants. The process was characterized by the use of Secondary Ion Mass Spectrometry (SIMS) and nuclear techniques (Rutherford Backscattering (RBS), Nuclear Reactions (NRA)), in order to determine concentration-depth profiles and by optical absorption and Transmission Electron Microscopy (TEM) measurements for the silver nanoclusters detection and size evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2759111','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2759111"><span id="translatedtitle">Size-<span class="hlt">Induced</span> Enhancement of Chemical <span class="hlt">Exchange</span> Saturation Transfer (CEST) Contrast in Liposomes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhao, Jason M.; Har-el, Yah-el; McMahon, Michael T.; Zhou, Jinyuan; Sherry, A. Dean; Sgouros, George; Bulte, Jeff W. M.; van Zijl, Peter C. M.</p> <p>2009-01-01</p> <p>Liposome-based chemical <span class="hlt">exchange</span> saturation transfer (lipoCEST) agents have shown great sensitivity and potential for molecular magnetic resonance imaging (MRI). Here we demonstrate that the size of liposomes can be exploited to enhance the lipoCEST contrast. A concise analytical model is developed to describe the contrast dependence on size for an ensemble of liposomes. The model attributes the increased lipoCEST contrast in smaller liposomes to their larger surface-to-volume ratio, causing an increased membrane water <span class="hlt">exchange</span> rate. Experimentally measured rates correlate with size, in agreement with the model. The water permeability of liposomal membrane is found to be 1.11 ± 0.14 μm/s for the specific lipid composition at 22 °C. Availability of the model allows rational design of the size of liposomes and quantification of their properties. These new theoretical and experimental tools are expected to benefit applications of liposomes to sensing the cellular environment, targeting and imaging biological processes, and optimizing drug delivery properties. PMID:18361490</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26479775','PUBMED'); return false;" href="http://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="http://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. PMID:26479775</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Nanos...5.6589M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Nanos...5.6589M"><span id="translatedtitle">Tunable properties <span class="hlt">induced</span> by ion <span class="hlt">exchange</span> in multilayer intertwined CuS microflowers with hierarchal structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mi, Liwei; Wei, Wutao; Zheng, Zhi; Gao, Yang; Liu, Yang; Chen, Weihua; Guan, Xinxin</p> <p>2013-06-01</p> <p>Novel hierarchical wool-ball-like copper sulfide (CuS) microflowers with a three-dimensional (3D) porous framework were successfully synthesized by the direct reaction of copper with sulfur powder using a one-pot in situ growth method at low temperature (60 °C). The CuS microflowers covered firmly the surface of the 3D porous framework. The formation mechanism was examined in detail by adjusting the amount of hydrochloric acid and reaction time. Most importantly, the chemical composition of the CuS microflowers was altered by the Se <span class="hlt">exchange</span> without changing their morphology and structure. In this way, pure CuSe and Cu1.8Se crystalline materials were obtained on the surface of the porous microtube at different reaction times and the appropriate amount of Se powder. And interestingly, the core material remained as CuS. This behavior greatly affects the physical and chemical properties of the materials. The catalytic ability of the as-obtained CuSe@CuS and CuSe1.8@CuS composite materials to degrade methylene blue and rhodamine B is several times greater than that of the as-synthesized CuS microflowers.Novel hierarchical wool-ball-like copper sulfide (CuS) microflowers with a three-dimensional (3D) porous framework were successfully synthesized by the direct reaction of copper with sulfur powder using a one-pot in situ growth method at low temperature (60 °C). The CuS microflowers covered firmly the surface of the 3D porous framework. The formation mechanism was examined in detail by adjusting the amount of hydrochloric acid and reaction time. Most importantly, the chemical composition of the CuS microflowers was altered by the Se <span class="hlt">exchange</span> without changing their morphology and structure. In this way, pure CuSe and Cu1.8Se crystalline materials were obtained on the surface of the porous microtube at different reaction times and the appropriate amount of Se powder. And interestingly, the core material remained as CuS. This behavior greatly affects the physical and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20863868','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20863868"><span id="translatedtitle">Pion-<span class="hlt">induced</span> double-charge <span class="hlt">exchange</span> reactions in the {delta} resonance region</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Buss, O.; Alvarez-Ruso, L.; Larionov, A. B.; Mosel, U.</p> <p>2006-10-15</p> <p>We have applied the Giessen BUU (GiBUU) transport model to the description of the double-charge <span class="hlt">exchange</span> (DCX) reaction of pions with different nuclear targets at incident kinetic energies of 120-180 MeV. The DCX process is highly sensitive to details of the interactions of pions with the nuclear medium and, therefore, represents a major benchmark for any model of pion scattering off nuclei at low and intermediate energies. The impact of surface effects, such as the neutron skins of heavy nuclei, is investigated. The dependence of the total cross section on the nuclear mass number is also discussed. We achieve a good quantitative agreement with the extensive data set obtained at LAMPF. Furthermore, we compare the solutions of the transport equations obtained in the test-particle ansatz using two different schemes: the full and the parallel ensemble methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26176908','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26176908"><span id="translatedtitle">Excess titanium dioxide nanoparticles on the cell surface <span class="hlt">induce</span> cytotoxicity by hindering ion <span class="hlt">exchange</span> and disrupting exocytosis processes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yanli; Yao, Chenjie; Li, Chenchen; Ding, Lin; Liu, Jian; Dong, Peng; Fang, Haiping; Lei, Zhendong; Shi, Guosheng; Wu, Minghong</p> <p>2015-08-14</p> <p>To date, considerable effort has been devoted to determine the potential toxicity of nanoparticles to cells and organisms. However, determining the mechanism of cytotoxicity <span class="hlt">induced</span> by different types of nanoparticles remains challenging. Herein, typically low toxicity nanomaterials were used as a model to investigate the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials. We studied the effect of nano-TiO2, nano-Al2O3 and nano-SiO2 deposition films on the ion concentration on a cell-free system simulating the cell membrane. The results showed that the ion concentration of K(+), Ca(2+), Na(+), Mg(2+) and SO4(2-) decreased significantly following filtration of the prepared deposition films. More specifically, at a high nano-TiO2 concentration (200 mg L(-1)) and a long nano-TiO2 deposition time (48 h), the concentration of Na(+) decreased from 2958.01 to 2775.72, 2749.86, 2757.36, and 2719.82 mg L(-1), respectively, for the four types of nano-TiO2 studied. Likewise, the concentration of SO4(2-) decreased from 38.83 to 35.00, 35.80, 35.40, and 35.27 mg L(-1), respectively. The other two kinds of typical low toxicity nanomaterials (nano-Al2O3 and nano-SiO2) have a similar impact on the ion concentration change trend. Adsorption of ions on nanoparticles and the hydrated shell around the ions strongly hindered the ions through the nanoparticle films. The endocytosed nanoparticles could be released from the cells without <span class="hlt">inducing</span> cytotoxicity. Hindering the ion <span class="hlt">exchange</span> and disrupting the exocytosis process are the main factors that <span class="hlt">induce</span> cytotoxicity in the presence of excess nano-TiO2 on the cell surface. The current findings may offer a universal principle for understanding the mechanism of cytotoxicity <span class="hlt">induced</span> by low toxicity nanomaterials. PMID:26176908</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/75589','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/75589"><span id="translatedtitle">Cis-acting determinants affecting centromere function, sister-<span class="hlt">chromatid</span> cohesion and reciprocal recombination during meiosis in Saccharomyces cerevisiae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sears, D.D.; Hieter, P.; Shero, J.H. |; Hegemann, J.H.</p> <p>1995-03-01</p> <p>We have employed a system that utilizes homologous pairs of human DNA-derived yeast artificial chromosomes (YACs) as marker chromosomes to assess the specific role(s) of conserved centromere DNA elements (CDEI, CDEII, and CDEIII) in meiotic chromosome disjunction fidelity. Thirteen different centromere (CEN) mutations were tested for their effects on meiotic centromere function. YACs containing a wild-type CEN DNA sequence segregate with high fidelity in meiosis I (99% normal segregation) and in meiosis II (96% normal segregation). YACs containing a 31-bp deletion mutation in centromere DNA element II (CDEII{Delta}31) in either a heterocentric (mutant/wild type), homocentric (mutant/mutant) or monosomic (mutant/-) YAC pair configuration exhibited high levels (16-28%) of precocious sister-<span class="hlt">chromatid</span> segregation (PSS) and increased levels (1-6%) of nondisjunction meiosis I (NDI). YACs containing this mutation also exhibit high levels (21%) of meiosis II nondisjunction. Interestingly, significant alterations in homolog recombination frequency were observed in the exceptional PSS class of tetrads, suggesting unusual interactions between prematurely separated sister <span class="hlt">chromatids</span> and their homologous nonsister <span class="hlt">chromatids</span>. We also have assessed the meiotic segregation effects of rare gene conversion events occurring at sites located immediately adjacent to or distantly from the centromere region. Proximal gene conversion events were associated with extremely high levels (60%) of meiosis I segregation errors (including both PSS and NDI), whereas distal events had no apparent effect. Taken together, our results indicate a critical role for CDEII in meiosis and underscore the importance of maintaining sister-<span class="hlt">chromatid</span> cohesion for proper recombination in meiotic prophase and for proper disjunction in meiosis I. 49 refs., 4 figs., 5 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/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('http://www.osti.gov/scitech/biblio/22486158','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22486158"><span id="translatedtitle">Spin dynamics <span class="hlt">induced</span> by ultrafast heating with ferromagnetic/antiferromagnetic interfacial <span class="hlt">exchange</span> in perpendicularly magnetized hard/soft bilayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ma, Q. L. E-mail: mizukami@wpi-aimr.tohoku.ac.jp; Miyazaki, T.; Mizukami, S. E-mail: mizukami@wpi-aimr.tohoku.ac.jp; Iihama, S.; Zhang, X. M.</p> <p>2015-11-30</p> <p>The laser-<span class="hlt">induced</span> spin dynamics of FeCo in perpendicularly magnetized L1{sub 0}-MnGa/FeCo bilayers with ferromagnetic and antiferromagnetic interfacial <span class="hlt">exchange</span> coupling (IEC) are examined using the time-resolved magneto-optical Kerr effect. We found a precessional phase reversal of the FeCo layer as the IEC changes from ferromagnetic to antiferromagnetic. Moreover, a precession-suspension window was observed when the magnetic field was applied in a certain direction for the bilayer with ferromagnetic IEC. Our observations reveal that the spin dynamics modulation is strongly dependent on the IEC type within the Landau-Lifshitz-Gilbert depiction. The IEC dependence of the precessional phase and amplitude suggests the interesting method for magnetization dynamics modulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.104b2407Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.104b2407Y"><span id="translatedtitle"><span class="hlt">Exchange</span> bias and magnetic properties <span class="hlt">induced</span> by intrinsic structural distortion in CaMn3O6 nanoribbons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, J. Y.; Huang, K.; Wu, H. Y.; Feng, Y.; Wang, L.; Tang, Z.; Zhang, L.</p> <p>2014-01-01</p> <p>Single-crystalline CaMn3O6 nanoribbons have been synthesized by a molten-salt method. To explore the origin of the magnetism of nanosized antiferromagnetic (AFM) manganites, a comparative study has been conducted for CaMn3O6 (CMO-1) and post-growth vacuum annealed (CMO-2) nanoribbons. A lattice expansion resulting from oxygen release during vacuum annealing is observed. Correspondingly, AFM ordering in CMO-2 is further suppressed, and ferromagnetism and spin-glass (SG)-like behavior are significantly enhanced, which are presumed attributable to the intrinsic structural distortions <span class="hlt">induced</span> by oxygen vacancies. In this case, side and surface effects are not decisive factors. In addition, this study provided observations of the <span class="hlt">exchange</span> bias effect in manganite nanoribbons with an AFM-SG-like-ferromagnetic (FM) structure, as compared with the typical AFM-core-FM-shell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..92l5148B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..92l5148B"><span id="translatedtitle">Interface <span class="hlt">exchange</span> processes in LaAlO3/Sr TiO3 <span class="hlt">induced</span> by oxygen vacancies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Behrmann, Malte; Lechermann, Frank</p> <p>2015-09-01</p> <p>Understanding the role of defects in oxide heterostructures is crucial for future materials control and functionalization. We hence study the impact of oxygen vacancies (OVs) at variable concentrations on orbital and spin <span class="hlt">exchange</span> in the LaAlO3/Sr TiO3 interface by first-principles many-body theory and real-space model-Hamiltonian techniques. Intricate interplay between the Hubbard U and Hund's coupling JH for OV-<span class="hlt">induced</span> correlated states is demonstrated. Orbital polarization towards an effective eg state with predominant local antiferromagnetic alignment on Ti sites near OVs is contrasted with t2 g(x y ) states with ferromagnetic tendencies in the defect-free regions. Different magnetic phases are identified, giving rise to distinct net-moment behavior at low and high OV concentrations. This provides a theoretical basis for prospective tailored magnetism by defect manipulation in oxide interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21335991','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21335991"><span id="translatedtitle">THE ION-<span class="hlt">INDUCED</span> CHARGE-<span class="hlt">EXCHANGE</span> X-RAY EMISSION OF THE JOVIAN AURORAS: MAGNETOSPHERIC OR SOLAR WIND ORIGIN?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hui Yawei; Schultz, David R.; Kharchenko, Vasili A.; Stancil, Phillip C.; Cravens, Thomas E.; Lisse, Carey M. E-mail: schultzd@ornl.gov E-mail: stancil@physast.uga.edu E-mail: carey.lisse@jhuapl.edu</p> <p>2009-09-10</p> <p>A new and more comprehensive model of charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions ({approx}0.7-2 MeV u{sup -1}), but infer a different relative sulfur-to-oxygen abundance ratio for these Chandra observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/974629','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/974629"><span id="translatedtitle">The Ion-<span class="hlt">induced</span> Charge-<span class="hlt">exchange</span> X-ray Emission of the Jovian Auroras: Magnetospheric or Solar Wind Origin?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hui, Yawei; Schultz, David Robert; Kharchenko, Vasili A; Stancil, Phillip C.; Cravens, Thomas E. E.; Lisse, Carey M.; Dalgarno, A.</p> <p>2009-01-01</p> <p>A new and more comprehensive model of charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions ( 0.7-2 MeV/u), but infer a different relative sulfur to oxygen abundance ratio for these Chandra observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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('http://www.osti.gov/scitech/biblio/7033558','SCIGOV-STC'); return false;" href="http://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://www.osti.gov/scitech/biblio/121755','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/121755"><span id="translatedtitle">Comparison of gamma-ray-<span class="hlt">induced</span> chromosome ring and inversion frequencies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Muehlmann, M.C.; Bedford, J.S.</p> <p>1995-08-01</p> <p>A method was used to detect chromosome inversions as apparent or false sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) in the first mitosis after {gamma} irradiation of human G{sub o} cells. Dose-response relationships for small inversions have not been measured and reported previously, but it has been assumed that these are <span class="hlt">induced</span> with a frequency equal to that of their easily mesured asymmetrical counterpart, the interstitial deletion. Our experiments confirm this expectation. The results also demonstrate, as others have suggested, that in protocols where SCEs have been reported in the first postirradiation mitosis after incorporation of BrdU in the previous cell cycle, the X- or {gamma}-ray treatment of G{sub o}{sup {minus}} or G{sub 1}-phase cells produces virtually no true SCEs. 23 refs., 3 figs., 2 tabs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24844569','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24844569"><span id="translatedtitle">On-line stable isotope gas <span class="hlt">exchange</span> reveals an <span class="hlt">inducible</span> but leaky carbon concentrating mechanism in Nannochloropsis salina.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hanson, David T; Collins, Aaron M; Jones, Howland D T; Roesgen, John; Lopez-Nieves, Samuel; Timlin, Jerilyn A</p> <p>2014-09-01</p> <p>Carbon concentrating mechanisms (CCMs) are common among microalgae, but their regulation and even existence in some of the most promising biofuel production strains is poorly understood. This is partly because screening for new strains does not commonly include assessment of CCM function or regulation despite its fundamental role in primary carbon metabolism. In addition, the <span class="hlt">inducible</span> nature of many microalgal CCMs means that environmental conditions should be considered when assessing CCM function and its potential impact on biofuels. In this study, we address the effect of environmental conditions by combining novel, high frequency, on-line (13)CO2 gas <span class="hlt">exchange</span> screen with microscope-based lipid characterization to assess CCM function in Nannochloropsis salina and its interaction with lipid production. Regulation of CCM function was explored by changing the concentration of CO2 provided to continuous cultures in airlift bioreactors where cell density was kept constant across conditions by controlling the rate of media supply. Our isotopic gas <span class="hlt">exchange</span> results were consistent with N. salina having an <span class="hlt">inducible</span> "pump-leak" style CCM similar to that of Nannochloropsis gaditana. Though cells grew faster at high CO2 and had higher rates of net CO2 uptake, we did not observe significant differences in lipid content between conditions. Since the rate of CO2 supply was much higher for the high CO2 conditions, we calculated that growing cells bubbled with low CO2 is about 40 % more efficient for carbon capture than bubbling with high CO2. We attribute this higher efficiency to the activity of a CCM under low CO2 conditions. PMID:24844569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=231210','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=231210"><span id="translatedtitle">Calcineurin inhibits VCX1-dependent H+/Ca2+ <span class="hlt">exchange</span> and <span class="hlt">induces</span> Ca2+ ATPases 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>Cunningham, K W; Fink, G R</p> <p>1996-01-01</p> <p>The PMC1 gene in Saccharomyces cerevisiae encodes a vacuolar Ca2+ ATPase required for growth in high-Ca2+ conditions. Previous work showed that Ca2+ tolerance can be restored to pmc1 mutants by inactivation of calcineurin, a Ca2+/calmodulin-dependent protein phosphatase sensitive to the immunosuppressive drug FK506. We now report that calcineurin decreases Ca2+ tolerance of pmc1 mutants by inhibiting the function of VCX1, which encodes a vacuolar H+/Ca2+ <span class="hlt">exchanger</span> related to vertebrate Na+/Ca2+ <span class="hlt">exchangers</span>. The contribution of VCX1 in Ca2+ tolerance is low in strains with a functional calcineurin and is high in strains which lack calcineurin activity. In contrast, the contribution of PMC1 to Ca2+ tolerance is augmented by calcineurin activation. Consistent with these positive and negative roles of calcineurin, expression of a vcx1::lacZ reporter was slightly diminished and a pmc1::lacZ reporter was <span class="hlt">induced</span> up to 500-fold by processes dependent on calcineurin, calmodulin, and Ca2+. It is likely that calcineurin inhibits VCX1 function mainly by posttranslational mechanisms. Activities of VCX1 and PMC1 help to control cytosolic free Ca2+ concentrations because their function can decrease pmc1::lacZ induction by calcineurin. Additional studies with reporter genes and mutants indicate that PMR1 and PMR2A, encoding P-type ion pumps required for Mn2+ and Na+ tolerance, may also be <span class="hlt">induced</span> physiologically in response to high-Mn2+ and -Na+ conditions through calcineurin-dependent mechanisms. In these situations, inhibition of VCX1 function may be important for the production of Ca2+ signals. We propose that elevated cytosolic free Ca2+ concentrations, calmodulin, and calcineurin regulate at least four ion transporters in S. cerevisiae in response to several environmental conditions. PMID:8628289</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4527282','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4527282"><span id="translatedtitle">Variations in dysfunction of sister <span class="hlt">chromatid</span> cohesion in esco2 mutant zebrafish reflect the phenotypic diversity of Roberts syndrome</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Percival, Stefanie M.; Thomas, Holly R.; Amsterdam, Adam; Carroll, Andrew J.; Lees, Jacqueline A.; Yost, H. Joseph; Parant, John M.</p> <p>2015-01-01</p> <p>ABSTRACT Mutations in ESCO2, one of two establishment of cohesion factors necessary for proper sister <span class="hlt">chromatid</span> cohesion (SCC), cause a spectrum of developmental defects in the autosomal-recessive disorder Roberts syndrome (RBS), warranting in vivo analysis of the consequence of cohesion dysfunction. Through a genetic screen in zebrafish targeting embryonic-lethal mutants that have increased genomic instability, we have identified an esco2 mutant zebrafish. Utilizing the natural transparency of zebrafish embryos, we have developed a novel technique to observe chromosome dynamics within a single cell during mitosis in a live vertebrate embryo. Within esco2 mutant embryos, we observed premature <span class="hlt">chromatid</span> separation, a unique chromosome scattering, prolonged mitotic delay, and genomic instability in the form of anaphase bridges and micronuclei formation. Cytogenetic studies indicated complete <span class="hlt">chromatid</span> separation and high levels of aneuploidy within mutant embryos. Amongst aneuploid spreads, we predominantly observed decreases in chromosome number, suggesting that either cells with micronuclei or micronuclei themselves are eliminated. We also demonstrated that the genomic instability leads to p53-dependent neural tube apoptosis. Surprisingly, although many cells required Esco2 to establish cohesion, 10-20% of cells had only weakened cohesion in the absence of Esco2, suggesting that compensatory cohesion mechanisms exist in these cells that undergo a normal mitotic division. These studies provide a unique in vivo vertebrate view of the mitotic defects and consequences of cohesion establishment loss, and they provide a compensation-based model to explain the RBS phenotypes. PMID:26044958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26044958','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26044958"><span id="translatedtitle">Variations in dysfunction of sister <span class="hlt">chromatid</span> cohesion in esco2 mutant zebrafish reflect the phenotypic diversity of Roberts syndrome.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Percival, Stefanie M; Thomas, Holly R; Amsterdam, Adam; Carroll, Andrew J; Lees, Jacqueline A; Yost, H Joseph; Parant, John M</p> <p>2015-08-01</p> <p>Mutations in ESCO2, one of two establishment of cohesion factors necessary for proper sister <span class="hlt">chromatid</span> cohesion (SCC), cause a spectrum of developmental defects in the autosomal-recessive disorder Roberts syndrome (RBS), warranting in vivo analysis of the consequence of cohesion dysfunction. Through a genetic screen in zebrafish targeting embryonic-lethal mutants that have increased genomic instability, we have identified an esco2 mutant zebrafish. Utilizing the natural transparency of zebrafish embryos, we have developed a novel technique to observe chromosome dynamics within a single cell during mitosis in a live vertebrate embryo. Within esco2 mutant embryos, we observed premature <span class="hlt">chromatid</span> separation, a unique chromosome scattering, prolonged mitotic delay, and genomic instability in the form of anaphase bridges and micronuclei formation. Cytogenetic studies indicated complete <span class="hlt">chromatid</span> separation and high levels of aneuploidy within mutant embryos. Amongst aneuploid spreads, we predominantly observed decreases in chromosome number, suggesting that either cells with micronuclei or micronuclei themselves are eliminated. We also demonstrated that the genomic instability leads to p53-dependent neural tube apoptosis. Surprisingly, although many cells required Esco2 to establish cohesion, 10-20% of cells had only weakened cohesion in the absence of Esco2, suggesting that compensatory cohesion mechanisms exist in these cells that undergo a normal mitotic division. These studies provide a unique in vivo vertebrate view of the mitotic defects and consequences of cohesion establishment loss, and they provide a compensation-based model to explain the RBS phenotypes. PMID:26044958</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27397686','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27397686"><span id="translatedtitle">Ctf4 Links DNA Replication with Sister <span class="hlt">Chromatid</span> Cohesion Establishment by Recruiting the Chl1 Helicase to the Replisome.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Samora, Catarina P; Saksouk, Julie; Goswami, Panchali; Wade, Ben O; Singleton, Martin R; Bates, Paul A; Lengronne, Armelle; Costa, Alessandro; Uhlmann, Frank</p> <p>2016-08-01</p> <p>DNA replication during S phase is accompanied by establishment of sister <span class="hlt">chromatid</span> cohesion to ensure faithful chromosome segregation. The Eco1 acetyltransferase, helped by factors including Ctf4 and Chl1, concomitantly acetylates the chromosomal cohesin complex to stabilize its cohesive links. Here we show that Ctf4 recruits the Chl1 helicase to the replisome via a conserved interaction motif that Chl1 shares with GINS and polymerase α. We visualize recruitment by EM analysis of a reconstituted Chl1-Ctf4-GINS assembly. The Chl1 helicase facilitates replication fork progression under conditions of nucleotide depletion, partly independently of Ctf4 interaction. Conversely, Ctf4 interaction, but not helicase activity, is required for Chl1's role in sister <span class="hlt">chromatid</span> cohesion. A physical interaction between Chl1 and the cohesin complex during S phase suggests that Chl1 contacts cohesin to facilitate its acetylation. Our results reveal how Ctf4 forms a replisomal interaction hub that coordinates replication fork progression and sister <span class="hlt">chromatid</span> cohesion establishment. PMID:27397686</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/115138','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/115138"><span id="translatedtitle">Increased frequencies of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE) in peripheral blood lymphocytes of U.S. troops deployed in Kuwait</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McDiarmid, M.A. Kolodner, K.; Scott, B.G.</p> <p>1995-11-01</p> <p>Concern over potential exposure of U.S. troops to genotoxic emissions generated in oil well fires prompted a Biologic Surveillance Initiative to examine levels of genetic damage in a cohort of troops deployed in Kuwait. Blood was drawn from members of the 11th Armored Cavalry Regiment on June 6, 1991 while they were stationed in Germany (PRE, n=61), on August 11, 1991 after being deployed in Kuwait (DURING, n=51) and again on October 10, 1991 after returning to Germany (POST, n=36). Cells were cultured for 68-72 hours in RPMI 1640 medium supplemented with 15% fetal bovine serum, 1% phytohemagglutinin and 10 {mu}g/ml 5-bromo-2`-deoxyuridine. Metaphase cells were prepared by standard techniques and stained with Hoechst 33258 plus Giemsa to visualize SCE. Whenever possible, a total of 25 well-spread and well-stained cells were evaluated for each individual. Only 26 soldiers had values available for all three sampling points. Data on 50 soldiers was available for PRE and DURING sampling while data on 35 samples was available for a PRE vs POST comparison. The average frequency of SCE/cell increased from 4.33 {plus_minus} 0.53 in the PRE samples to 5.12 {plus_minus} 0.64 in the DURING samples to 5.28 {plus_minus} 0.72 in the POST samples. The PRE values were significantly different from both the DURING and POST values (p<0.001) using the paired t-test. While these results suggest that this cohort was potentially exposed to genotoxic materials, the source of the exposure(s) is presently not known.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=48048&keyword=bone+AND+marrow&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=75615756&CFTOKEN=86746968','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=48048&keyword=bone+AND+marrow&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=75615756&CFTOKEN=86746968"><span id="translatedtitle">KINETICS OF IN VIVO SISTER <span class="hlt">CHROMATID</span> <span class="hlt">EXCHANGE</span> INDUCTION IN MOUSE BONE MARROW CELLS IN ETHYLNITROSOUREA AND METHYLNITROSOUREA</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>Administration of ethylnitrosourea (ENU) (20, 25, 40, 50, and 60 mg/kg body weight) or methylnitrosourea (MNU) (25, 40, 50, 60, 75, and 80 mg/kg body weight) to male CD-1 mice 2 hours after subcutaneous implantation of 5-bromo-2'-deoxyurdine (BrdUrd) pellet (55 mg) resulted in a ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=37643&keyword=bone+AND+marrow&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=75615756&CFTOKEN=86746968','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=37643&keyword=bone+AND+marrow&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=75615756&CFTOKEN=86746968"><span id="translatedtitle">SISTER <span class="hlt">CHROMATID</span> <span class="hlt">EXCHANGE</span> AND CHROMOSOME ABERRATION ANALYSES IN MICE AFTER IN VIVO EXPOSURE TO ACRYLONITRILE, STYRENE, OR BUTADIENE MONOXIDE</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>The use of polymers in plastic and rubber products has generated concern that monomers potentially active in biological systems may be eluted from these substances. The authors have evaluated two such monomers, acrylonitrile and styrene, for the induction of chromosome damage in ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=49074&keyword=p1&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=75511804&CFTOKEN=84302941','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=49074&keyword=p1&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=75511804&CFTOKEN=84302941"><span id="translatedtitle">DNA ADDUCTS AND INDUCTION OF SISTER <span class="hlt">CHROMATID</span> <span class="hlt">EXCHANGES</span> IN THE RAT FOLLOWING BENZO[B]FLUORANTHENE ADMINISTRATION</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>Male Sprague Dawley rats were injected with single i.p. doses of benzo[a]pyrene (B[a]P), and peripheral blood lymphocytes (PBLs), livers, and lungs were removed at various times after administration. NA adducts, analyzed by 32P-postlabeling with nuclease P1 enhancement, were obse...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=34365&keyword=Gupta&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=61143919&CFTOKEN=51255392','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=34365&keyword=Gupta&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=61143919&CFTOKEN=51255392"><span id="translatedtitle">DNA ADDUCTS AND INDUCTION OF SISTER <span class="hlt">CHROMATID</span> <span class="hlt">EXCHANGES</span> IN THE RAT FOLLOWING BENZO(B)FLUORANTHENE ADMINISTRATION</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>Benzo[b]fluoranthene (B[b]F) was administered (100 mg/kg by i.p. injection) to male Sprague-Dawley rats. Lungs, livers, and peripheral blood lymphocytes (PBLs) were harvested 1, 3, 5, 7, 14, 28, and 56 days after treatment. Several DNA adducts were observed in each tissue, with m...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARA50012B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARA50012B"><span id="translatedtitle"><span class="hlt">Exchange</span> interaction and the tunneling <span class="hlt">induced</span> transparency in coupled quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borges, Halyne; Alcalde, Augusto; Ulloa, Sergio</p> <p>2014-03-01</p> <p>Stacked semiconductor quantum dots coupled by tunneling are unique ``quantum molecule'' where it is possible to create a multilevel structure of excitonic states. This structure allows the investigation of quantum interference processes and their control via electric external fields. In this work, we investigate the optical response of a quantum molecule coherently driven by a polarized laser, considering the splitting in excitonic levels caused by isotropic and anisotropic <span class="hlt">exchange</span> interactions. In our model we consider interdot transitions mediated by the the hole tunneling between states with the same total spin and, between bright and dark exciton states. Using realistic experimental parameters, we demonstrate that the excitonic states coupled by tunneling exhibit an enriched and controllable optical response. Our results show that through the appropriate control of the external electric field and light polarization, the tunneling coupling establishes an efficient destructive quantum interference path that creates a transparency window in the absorption spectra, whenever states of appropriate symmetry are mixed by the hole tunneling. We explore the relevant parameters space that would allows with the experiments. CAPES, INCT-IQ and MWN/CIAM-NSF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13E..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13E..04S"><span id="translatedtitle">Modeling coupled thermal-mechanical processes of frozen soil <span class="hlt">induced</span> by borehole heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shao, H.</p> <p>2015-12-01</p> <p>To utilize the shallow geothermal energy, heat pumps are often coupled with Borehole Heat <span class="hlt">Exchangers</span> (BHE) to provide heating and cooling for buildings. In cold regions, soil freezing around the BHE is a potential problem which will dramatically influence the underground soil temperature distribution, subsequently the inlet and outlet refrigerant temperature of the BHE, and finally the efficiency of the heat pump. In this study, a numerical model has been developed to simulate the coupled temperature evolution both inside the BHE, and the propagating freezing front in the surrounding soil. The coupled model was validated against analytical solutions and experimental data. The influence of the freezing process on the overall system performance is investigated by comparing one long BHE configuration without freezing and another short one with latent heat from the frozen groundwater. It is found that when freezing happens, the coefficient of performance (COP) of the heat pump will decrease by around 0.5, leading to more electricity consumption. Furthermore, analysis of the simulation result reveals that the exploitation of latent heat through groundwater freezing is only economically attractive if electricity price is low and interest rate high, and it is not the case is most European countries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004A%26A...422..391L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004A%26A...422..391L"><span id="translatedtitle">On the contribution of charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission in the ISM and ICM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lallement, R.</p> <p>2004-08-01</p> <p>X-ray emission can be generated by charge-<span class="hlt">exchange</span> (CXE) between highly charged ions of a hot plasma and neutral species of an interacting cool/warm gas, a phenomenon recently observed in the case of the solar wind interaction with cometary, interstellar, and geocoronal neutrals (Lisse et al. \\cite{Lisse96}; Cox \\cite{Cox98}; Cravens \\cite{Cravens97}, \\cite{Cravens02}). Charge-<span class="hlt">exchange</span> processes are included in most theoretical models of hot interstellar plasmas interacting with partially neutral gas, resulting in a modification of the physical states of the gases in the interaction region. However, the contribution of the charge-<span class="hlt">exchange</span> <span class="hlt">induced</span> X-ray emission produced at these interfaces has hitherto not been considered to be significant. The detailed calculations performed by Wise & Sarazin (\\cite{Wise89}), motivated by the observations of X-ray emission following charge-<span class="hlt">exchange</span> in laboratory fusion devices, have shown that the emission is negligible in the case of an SNR fast shock. Our goal here is to investigate its relative importance in different astrophysical cases. We simplistically consider interfaces between partially neutral and hot gas in the following cases: (a) a supernova blast wave propagating in a neutral (or partially ionized) ISM (b) a galactic wind engulfing a halo dense cloud; (c) a high velocity cloud (HVC) moving through the halo, and (c) a dense cloud moving in intra-cluster gas. Although the phenomenon is restricted to the very narrow envelopes defined by the mean free path of the neutrals through the hot plasma, it is easy to show that its efficiency is such that the volume emissivity from these interfaces can be orders of magnitude above the emissivity of the hot gas itself, and, more important, that its relative contribution increases with decreasing hot gas density. As a consequence it should be at maximum in mixing layers in very low density hot gas. Our preliminary results suggest that the charge-<span class="hlt">exchange</span> X-ray emission from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26643143','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26643143"><span id="translatedtitle">PICH promotes sister <span class="hlt">chromatid</span> disjunction and co-operates with topoisomerase II in mitosis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nielsen, Christian F; Huttner, Diana; Bizard, Anna H; Hirano, Seiki; Li, Tian-Neng; Palmai-Pallag, Timea; Bjerregaard, Victoria A; Liu, Ying; Nigg, Erich A; Wang, Lily Hui-Ching; Hickson, Ian D</p> <p>2015-01-01</p> <p>PICH is a SNF2 family DNA translocase that binds to ultra-fine DNA bridges (UFBs) in mitosis. Numerous roles for PICH have been proposed from protein depletion experiments, but a consensus has failed to emerge. Here, we report that deletion of PICH in avian cells causes chromosome structural abnormalities, and hypersensitivity to an inhibitor of Topoisomerase II (Topo II), ICRF-193. ICRF-193-treated PICH(-/-) cells undergo sister <span class="hlt">chromatid</span> non-disjunction in anaphase, and frequently abort cytokinesis. PICH co-localizes with Topo IIα on UFBs and at the ribosomal DNA locus, and the timely resolution of both structures depends on the ATPase activity of PICH. Purified PICH protein strongly stimulates the catalytic activity of Topo II in vitro. Consistent with this, a human PICH(-/-) cell line exhibits chromosome instability and chromosome condensation and decatenation defects similar to those of ICRF-193-treated cells. We propose that PICH and Topo II cooperate to prevent chromosome missegregation events in mitosis. PMID:26643143</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686863','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686863"><span id="translatedtitle">PICH promotes sister <span class="hlt">chromatid</span> disjunction and co-operates with topoisomerase II in mitosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nielsen, Christian F.; Huttner, Diana; Bizard, Anna H.; Hirano, Seiki; Li, Tian-Neng; Palmai-Pallag, Timea; Bjerregaard, Victoria A.; Liu, Ying; Nigg, Erich A.; Wang, Lily Hui-Ching; Hickson, Ian D.</p> <p>2015-01-01</p> <p>PICH is a SNF2 family DNA translocase that binds to ultra-fine DNA bridges (UFBs) in mitosis. Numerous roles for PICH have been proposed from protein depletion experiments, but a consensus has failed to emerge. Here, we report that deletion of PICH in avian cells causes chromosome structural abnormalities, and hypersensitivity to an inhibitor of Topoisomerase II (Topo II), ICRF-193. ICRF-193-treated PICH−/− cells undergo sister <span class="hlt">chromatid</span> non-disjunction in anaphase, and frequently abort cytokinesis. PICH co-localizes with Topo IIα on UFBs and at the ribosomal DNA locus, and the timely resolution of both structures depends on the ATPase activity of PICH. Purified PICH protein strongly stimulates the catalytic activity of Topo II in vitro. Consistent with this, a human PICH−/− cell line exhibits chromosome instability and chromosome condensation and decatenation defects similar to those of ICRF-193-treated cells. We propose that PICH and Topo II cooperate to prevent chromosome missegregation events in mitosis. PMID:26643143</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5997976','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5997976"><span id="translatedtitle">Proliferative kinetics of human lymphocytes in culture measured by autoradiography and sister <span class="hlt">chromatid</span> differential staining</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morimoto, K.; Sato, M.; Koizumi, A.</p> <p>1983-01-01</p> <p>A simple combination of autoradiography, to determine when a cell synthesized DNA, and sister <span class="hlt">chromatid</span> differential staining, to determine how many times a cell has divided, was used to follow up the proliferating fate of human lymphocytes in culture. Cells were incubated continuously with 5-bromodeoxyuridine (BrdU) and pulse-labelled with 0.1 ..mu..Ci/ml (/sup 3/H)thymidine at various times after stimulation with phytohemagglutinin (PHA). The cells were then harvested at 4 h intervals up to 72 h, and the percentage of labelled mitoses was determined separately in first, second, or third division cells. The data showed that the cycling cells, whether they began cycling at earlier or later times after stimulation, had about the same generation times of 12-14 h. This confirms that the heterogeneity of cell generations seen in short-term lymphocyte cultures is in large part due to the difference in the times when cells began cell cycling in response to PHA. 34 references, 2 figures, 1 table.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1635493','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1635493"><span id="translatedtitle">Effects of sister <span class="hlt">chromatid</span> cohesion proteins on cut gene expression during wing development in Drosophila</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dorsett, Dale; Eissenberg, Joel C.; Misulovin, Ziva; Martens, Andrew; Redding, Bethany; McKim, Kim</p> <p>2006-01-01</p> <p>Summary The cohesin protein complex is a conserved structural component of chromosomes. Cohesin binds numerous sites along interphase chromosomes and is essential for sister <span class="hlt">chromatid</span> cohesion and DNA repair. Here, we test the idea that cohesin also regulates gene expression. This idea arose from the finding that the Drosophila Nipped-B protein, a functional homolog of the yeast Scc2 factor that loads cohesin onto chromosomes, facilitates the transcriptional activation of certain genes by enhancers located many kilobases away from their promoters. We find that cohesin binds between a remote wing margin enhancer and the promoter at the cut locus in cultured cells, and that reducing the dosage of the Smc1 cohesin subunit increases cut expression in the developing wing margin. We also find that cut expression is increased by a unique pds5 gene mutation that reduces the binding of cohesin to chromosomes. On the basis of these results, we posit that cohesin inhibits long-range activation of the Drosophila cut gene, and that Nipped-B facilitates activation by regulating cohesin-chromosome binding. Such effects of cohesin on gene expression could be responsible for many of the developmental deficits that occur in Cornelia de Lange syndrome, which is caused by mutations in the human homolog of Nipped-B. PMID:16207752</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24797474','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24797474"><span id="translatedtitle">Meiotic cohesin STAG3 is required for chromosome axis formation and sister <span class="hlt">chromatid</span> cohesion.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Winters, Tristan; McNicoll, Francois; Jessberger, Rolf</p> <p>2014-06-01</p> <p>The cohesin complex is essential for mitosis and meiosis. The specific meiotic roles of individual cohesin proteins are incompletely understood. We report in vivo functions of the only meiosis-specific STAG component of cohesin, STAG3. Newly generated STAG3-deficient mice of both sexes are sterile with meiotic arrest. In these mice, meiotic chromosome architecture is severely disrupted as no bona fide axial elements (AE) form and homologous chromosomes do not synapse. Axial element protein SYCP3 forms dot-like structures, many partially overlapping with centromeres. Asynapsis marker HORMAD1 is diffusely distributed throughout the chromatin, and SYCP1, which normally marks synapsed axes, is largely absent. Centromeric and telomeric sister <span class="hlt">chromatid</span> cohesion are impaired. Centromere and telomere clustering occurs in the absence of STAG3, and telomere structure is not severely affected. Other cohesin proteins are present, localize throughout the STAG3-devoid chromatin, and form complexes with cohesin SMC1β. No other deficiency in a single meiosis-specific cohesin causes a phenotype as drastic as STAG3 deficiency. STAG3 emerges as the key STAG cohesin involved in major functions of meiotic cohesin. PMID:24797474</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3784504','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3784504"><span id="translatedtitle">Histone Chaperone NAP1 Mediates Sister <span class="hlt">Chromatid</span> Resolution by Counteracting Protein Phosphatase 2A</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kan, Tsung-Wai; Chalkley, Gillian E.; Sap, Karen; Bezstarosti, Karel; Demmers, Jeroen A.; Ozgur, Zeliha; van Ijcken, Wilfred F. J.; Verrijzer, C. Peter</p> <p>2013-01-01</p> <p>Chromosome duplication and transmission into daughter cells requires the precisely orchestrated binding and release of cohesin. We found that the Drosophila histone chaperone NAP1 is required for cohesin release and sister <span class="hlt">chromatid</span> resolution during mitosis. Genome-wide surveys revealed that NAP1 and cohesin co-localize at multiple genomic loci. Proteomic and biochemical analysis established that NAP1 associates with the full cohesin complex, but it also forms a separate complex with the cohesin subunit stromalin (SA). NAP1 binding to cohesin is cell-cycle regulated and increases during G2/M phase. This causes the dissociation of protein phosphatase 2A (PP2A) from cohesin, increased phosphorylation of SA and cohesin removal in early mitosis. PP2A depletion led to a loss of centromeric cohesion. The distinct mitotic phenotypes caused by the loss of either PP2A or NAP1, were both rescued by their concomitant depletion. We conclude that the balanced antagonism between NAP1 and PP2A controls cohesin dissociation during mitosis. PMID:24086141</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198028','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4198028"><span id="translatedtitle">Meiotic cohesin STAG3 is required for chromosome axis formation and sister <span class="hlt">chromatid</span> cohesion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Winters, Tristan; McNicoll, Francois; Jessberger, Rolf</p> <p>2014-01-01</p> <p>The cohesin complex is essential for mitosis and meiosis. The specific meiotic roles of individual cohesin proteins are incompletely understood. We report in vivo functions of the only meiosis-specific STAG component of cohesin, STAG3. Newly generated STAG3-deficient mice of both sexes are sterile with meiotic arrest. In these mice, meiotic chromosome architecture is severely disrupted as no bona fide axial elements (AE) form and homologous chromosomes do not synapse. Axial element protein SYCP3 forms dot-like structures, many partially overlapping with centromeres. Asynapsis marker HORMAD1 is diffusely distributed throughout the chromatin, and SYCP1, which normally marks synapsed axes, is largely absent. Centromeric and telomeric sister <span class="hlt">chromatid</span> cohesion are impaired. Centromere and telomere clustering occurs in the absence of STAG3, and telomere structure is not severely affected. Other cohesin proteins are present, localize throughout the STAG3-devoid chromatin, and form complexes with cohesin SMC1β. No other deficiency in a single meiosis-specific cohesin causes a phenotype as drastic as STAG3 deficiency. STAG3 emerges as the key STAG cohesin involved in major functions of meiotic cohesin. PMID:24797474</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010JGRG..115.3026S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010JGRG..115.3026S&link_type=ABSTRACT"><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('http://www.ncbi.nlm.nih.gov/pubmed/25877869','PUBMED'); return false;" href="http://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="http://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. PMID:25877869</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24727538','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24727538"><span id="translatedtitle">Experience of Treatments of Amanita phalloides-<span class="hlt">Induced</span> Fulminant Liver Failure with Molecular Adsorbent Recirculating System and Therapeutic Plasma <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Jicheng; Zhang, Ying; Peng, Zhiyong; Maberry, Donald; Feng, Xueqiang; Bian, Pengfei; Ma, Wenjuan; Wang, Chunting; Qin, Chengyong</p> <p>2014-01-01</p> <p>Ingestion of the mushroom containing Amanita phalloides can <span class="hlt">induce</span> fulminant liver failure and death. There are no specific antidotes. Blood purifications, such as molecular adsorbent recirculating system (MARS) and therapeutic plasma <span class="hlt">exchange</span> (TPE), are potential therapies. However, the extent to which these technologies avert the deleterious effects of amatoxins remains controversial; the optimal intensity, duration, and initiation criteria have not been determined yet. This study aimed to retrospectively observe the effects of MARS and TPE on nine patients with A. phalloides-<span class="hlt">induced</span> fulminant liver failure. The survival rate for the nine patients was 66.7%. Both TPE and MARS might remove toxins and improve liver functions. However, a single session of TPE produced immediately greater improvements in alanine aminotransferase (-60% vs. -16.3%), aspartate aminotransferase (-47.6% vs. -15.4%), and total bilirubin (-37.3% vs. -17.1%) (compared with the values of pretreatment, all p < 0.05) than MARS compared with MARS. Early intervention may be more effective than delayed therapy. Additionally, the presence of severe liver failure and renal failure indicated worse outcome. Although these findings are promising, additional case-controlled, randomized studies are required to confirm our results. PMID:24727538</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007OptMa..29..987N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007OptMa..29..987N"><span id="translatedtitle">Beam power-dependent laser-<span class="hlt">induced</span> fluorescence radiation quenching of silver-ion-<span class="hlt">exchanged</span> glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nahal, Arashmid; Khalesifard, Hamid Reza M.</p> <p>2007-04-01</p> <p>In this article, results of an investigation about the modification of silver ions embedded in a glass matrix under the action of a CW high-power Ar + laser beam, by means of laser-<span class="hlt">induced</span> fluorescence, is reported. It is known [A. Nahal, H.R.M. Khalesifard, J. Mostafavi-Amjad, Appl. Phys. B 79 (2004) 513-518] that, as a result of the interaction of the laser beam with the sample, the embedded silver ions reduce to neutral ones and silver clusters are formed. We observed that the fluorescence radiation of the central part of the interaction area, on the sample, diminishes simultaneously with the formation of the neutral clusters. Further increase in the exposure time or the power of the beam results in reappearance of the fluorescence radiation, in the central part of the interaction area. We found that, during and after the interaction the spectrum of the fluorescence radiation changes. This makes it possible to study the laser-<span class="hlt">induced</span> changes in the embedded silver ions and clusters, in real-time.</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://www.ncbi.nlm.nih.gov/pubmed/27074433','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27074433"><span id="translatedtitle">Regioselective Lithium-Iodine <span class="hlt">Exchange</span>-Initiated Cleavage of 2-Iodomethyl-1,3-dioxanes: A Complex-<span class="hlt">Induced</span> Proximity Effect.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bailey, William F; Fair, Justin D</p> <p>2016-05-01</p> <p>Lithium-iodine <span class="hlt">exchange</span>-initiated fragmentation of a series of 4-substituted 2-iodomethyl-1,3-dioxanes proceeds rapidly and regioselectively to afford enol ether alcohols by preferential cleavage of the less congested C(2)-O(1) bond. The results demonstrate that a complex-<span class="hlt">induced</span> proximity effect (CIPE) is likely responsible for the selectivity of the cleavage. PMID:27074433</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AGUFM.B22A0744V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AGUFM.B22A0744V&link_type=ABSTRACT"><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://www.ncbi.nlm.nih.gov/pubmed/19823170','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19823170"><span id="translatedtitle">Compensatory role of <span class="hlt">inducible</span> annexin A2 for impaired biliary epithelial anion-<span class="hlt">exchange</span> activity of inflammatory cholangiopathy.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kido, Osamu; Fukushima, Koji; Ueno, Yoshiyuki; Inoue, Jun; Jefferson, Douglas M; Shimosegawa, Tooru</p> <p>2009-12-01</p> <p>The peribiliary inflammation of cholangiopathy affects the physiological properties of biliary epithelial cells (cholangiocyte), including bicarbonate-rich ductular secretion. We revealed the upregulation of annexin A2 (ANXA2) in cholangiocytes in primary biliary cirrhosis (PBC) by a proteomics approach and evaluated its physiological significance. Global protein expression profiles of a normal human cholangiocyte line (H69) in response to interferon-gamma (IFNgamma) were obtained by two-dimensional electrophoresis followed by MALDI-TOF-MS. Histological expression patterns of the identified molecules in PBC liver were confirmed by immunostaining. H69 cells stably transfected with doxycyclin-<span class="hlt">inducible</span> ANXA2 were subjected to physiological evaluation. Recovery of the intracellular pH after acute alkalinization was measured consecutively by a pH indicator with a specific inhibitor of anion <span class="hlt">exchanger</span> (AE), 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). Protein kinase-C (PKC) activation was measured by PepTag Assay and immunoblotting. Twenty spots that included ANXA2 were identified as IFNgamma-responsive molecules. Cholangiocytes of PBC liver were decorated by the unique membranous overexpression of ANXA2. Apical ANXA2 of small ducts of PBC was directly correlated with the clinical cholestatic markers and transaminases. Controlled induction of ANXA2 resulted in significant increase of the DIDS-inhibitory fraction of AE activity of H69, which was accompanied by modulation of PKC activity. We, therefore, identified ANXA2 as an IFNgamma-<span class="hlt">inducible</span> gene in cholangiocytes that could serve as a potential histological marker of inflammatory cholangiopathy, including PBC. We conclude that <span class="hlt">inducible</span> ANXA2 expression in cholangiocytes may play a compensatory role for the impaired AE activity of cholangiocytes in PBC in terms of bicarbonate-rich ductular secretion and bile formation through modulation of the PKC activity. PMID:19823170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..287M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..287M"><span id="translatedtitle">Eddy <span class="hlt">induced</span> Temperature <span class="hlt">Exchange</span> between Subpolar and Subtropical Gyre - a comparison of observations and model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, Vasco; Kieke, Dagmar; Myers, Paul G.; Mertens, Christian; Pennelly, Clark</p> <p>2016-04-01</p> <p>Eddies in the subpolar North Atlantic play an important role for temperature, freshwater and volume fluxes across the front between the subpolar and subtropical gyre and thus influence the hydrography and dynamics in the Subarctic and Arctic realm. Here, we ask where and how eddy <span class="hlt">induced</span> mixing takes place, if there are localized hotspots of mixing and what are the main pathways of eddies between the gyres. We analyze the eddy field in more than 20 years of satellite altimetry observations with 1/4° horizontal resolution, using a geometry based eddy detection and tracking algorithm. To estimate the respective temperature flux of individual eddies, the eddy surface area and translation speed from the eddy detection and tracking algorithm are combined with anomalies of a real-time global sea surface temperature (SST) analysis. In order to analyze the effect of resolution on the results, we compare the findings in the observations to model experiments with the NEMO ocean model using two different set-ups: (1) ANHA4 with 1/4° horizontal resolution and (2) ANHA4 with an nested 1/12° horizontal resolution encompassing the subpolar North Atlantic. For the analysis of the temperature flux, we focus on the zonal section at 47°N as it represents a good approximation for the gyre boundary. Additionally, we have ship based velocity observations from 10 cruises between 2003 and 2014 available for this section, that allow us to compare the observed eddy temperature flux to the mean circulation across the section. In both observations and model, the shear region between Western Boundary Current, North Atlantic Current and the recirculation cell in the Newfoundland Basin is the most active region regarding eddy activity and eddy <span class="hlt">induced</span> temperature flux across 47°N.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7683769','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7683769"><span id="translatedtitle">Increasing effect of tri-n-butyltins and triphenyltins on the frequency of chemically <span class="hlt">induced</span> chromosome aberrations in cultured Chinese hamster cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sasaki, Y F; Yamada, H; Sugiyama, C; Kinae, N</p> <p>1993-06-01</p> <p>Organotins have been widely used as anti-fouling coatings for fishing nets and ship bottoms, and marine pollution by them has become a serious environmental problem. In this communication, the potentiating effects of three kinds of tri-n-butyltins and three thiphenyltins on chromosome aberrations were studied in Chinese hamster CHO K1 cells. None of the organotins studied showed any clastogenic activity under the experimental conditions without rat liver S9. Post-treatment with organotins, however, increased the number of breakage-type (but not <span class="hlt">exchange</span>-type) <span class="hlt">chromatid</span> aberrations <span class="hlt">induced</span> by five kinds of S-phase-dependent clastogens: MMC, cisPt, 4NQO, MMS, and AMD). Enhancement of the induction of chromosome aberrations by MMC was observed when cells were treated with organotins during the G2 phase. These results suggest that organotin G2 effect causes potentiating effects. Organotins also enhanced the induction of breakage-type <span class="hlt">chromatid</span> aberrations by clastogenic pollutants in chlorinated tap water, indicating their potential for a more realistic health risk. PMID:7683769</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25964420','PUBMED'); return false;" href="http://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="http://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. PMID:25964420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510840','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510840"><span id="translatedtitle">Oxygen-limited thermal tolerance is seen in a plastron-breathing insect and can be <span class="hlt">induced</span> in a bimodal gas <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Verberk, Wilco C. E. P.; Bilton, David T.</p> <p>2015-01-01</p> <p>ABSTRACT Thermal tolerance has been hypothesized to result from a mismatch between oxygen supply and demand. However, the generality of this hypothesis has been challenged by studies on various animal groups, including air-breathing adult insects. Recently, comparisons across taxa have suggested that differences in gas <span class="hlt">exchange</span> mechanisms could reconcile the discrepancies found in previous studies. Here, we test this suggestion by comparing the behaviour of related insect taxa with different gas <span class="hlt">exchange</span> mechanisms, with and without access to air. We demonstrate oxygen-limited thermal tolerance in air-breathing adults of the plastron-<span class="hlt">exchanging</span> water bug Aphelocheirus aestivalis. Ilyocoris cimicoides, a related, bimodal gas <span class="hlt">exchanger</span>, did not exhibit such oxygen-limited thermal tolerance and relied increasingly on aerial gas <span class="hlt">exchange</span> with warming. Intriguingly, however, when denied access to air, oxygen-limited thermal tolerance could also be <span class="hlt">induced</span> in this species. Patterns in oxygen-limited thermal tolerance were found to be consistent across life-history stages in these insects, with nymphs employing the same gas <span class="hlt">exchange</span> mechanisms as adults. These results advance our understanding of oxygen limitation at high temperatures; differences in the degree of respiratory control appear to modulate the importance of oxygen in setting tolerance limits. PMID:25964420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20130010162&hterms=LL&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DLL','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20130010162&hterms=LL&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DLL"><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/2015JMMM..394..349G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMMM..394..349G"><span id="translatedtitle">Magnetoelastically <span class="hlt">induced</span> perpendicular magnetic anisotropy and perpendicular <span class="hlt">exchange</span> bias of CoO/CoPt multilayer films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Lei; Wang, Yue; Wang, Jian; Muraishi, Shinji; Sannomiya, Takumi; Nakamura, Yoshio; Shi, Ji</p> <p>2015-11-01</p> <p>The effects of magnetoelastically <span class="hlt">induced</span> perpendicular magnetic anisotropy (PMA) on perpendicular <span class="hlt">exchange</span> bias (PEB) have been studied in [CoO5nm/CoPt5nm]5 multilayer films. After deposition at room temperature, [CoO5nm/CoPt5nm]5 multilayer films were post-annealed at 100 °C, 250 °C, 300 °C and 375 °C for 3 h. In-plane tensile stress of CoPt layer was calculated by sin2 φ method, and we found it increased gradually upon annealing from 0.99 GPa (as-deposited) up to 3.02 GPa (300 °C-annealed). As to the magnetic property, significant enhancement of PMA was achieved in [CoO5nm/CoPt5nm]5 multilayer films after annealing due to the increase of CoPt layer in-plane tensile stress. With the enhancement of magnetoelastically <span class="hlt">induced</span> PMA, great improvement of PEB was also achieved in [CoO5nm/CoPt5nm]5 multilayer films, which increased from 130 Oe (as-deposited) up to 1060 Oe (300 °C-annealed), showing the same change tendency as PMA and the strong correlation with CoPt layer in-plane tensile stress. We consider it is the increase of CoPt layer in-plane tensile stress that leads to the enhancement of CoPt layer PMA, which is favorable for the spins in CoPt layer aligning to a more perpendicular direction. And thus the enhanced PMA with more perpendicular spins alignment in CoPt layer results in the improved PEB in [CoO5nm/CoPt5nm]5 multilayer films through enhanced perpendicular spins coupling at CoO/CoPt interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3441363','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3441363"><span id="translatedtitle">Inhibitor of neuronal nitric oxide synthase improves gas <span class="hlt">exchange</span> in ventilator-<span class="hlt">induced</span> lung injury after pneumonectomy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Mechanical ventilation with high tidal volumes may cause ventilator-<span class="hlt">induced</span> lung injury (VILI) and enhanced generation of nitric oxide (NO). We demonstrated in sheep that pneumonectomy followed by injurious ventilation promotes pulmonary edema. We wished both to test the hypothesis that neuronal NOS (nNOS), which is distributed in airway epithelial and neuronal tissues, could be involved in the pathogenesis of VILI and we also aimed at investigating the influence of an inhibitor of nNOS on the course of VILI after pneumonectomy. Methods Anesthetized sheep underwent right pneumonectomy, mechanical ventilation with tidal volumes (VT) of 6 mL/kg and FiO2 0.5, and were subsequently randomized to a protectively ventilated group (PROTV; n = 8) keeping VT and FiO2 unchanged, respiratory rate (RR) 25 inflations/min and PEEP 4 cm H2O for the following 8 hrs; an injuriously ventilated group with VT of 12 mL/kg, zero end-expiratory pressure, and FiO2 and RR unchanged (INJV; n = 8) and a group, which additionally received the inhibitor of nNOS, 7-nitroindazole (NI) 1.0 mg/kg/h intravenously from 2 hours after the commencement of injurious ventilation (INJV + NI; n = 8). We assessed respiratory, hemodynamic and volumetric variables, including both the extravascular lung water index (EVLWI) and the pulmonary vascular permeability index (PVPI). We measured plasma nitrite/nitrate (NOx) levels and examined lung biopsies for lung injury score (LIS). Results Both the injuriously ventilated groups demonstrated a 2–3-fold rise in EVLWI and PVPI, with no significant effects of NI. In the INJV group, gas <span class="hlt">exchange</span> deteriorated in parallel with emerging respiratory acidosis, but administration of NI antagonized the derangement of oxygenation and the respiratory acidosis significantly. NOx displayed no significant changes and NI exerted no significant effect on LIS in the INJV group. Conclusion Inhibition of nNOS improved gas <span class="hlt">exchange</span>, but did not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=364730','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=364730"><span id="translatedtitle">Delayed chromosomal instability <span class="hlt">induced</span> by DNA damage.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marder, B A; Morgan, W F</p> <p>1993-01-01</p> <p>DNA damage <span class="hlt">induced</span> by ionizing radiation can result in gene mutation, gene amplification, chromosome rearrangements, cellular transformation, and cell death. Although many of these changes may be <span class="hlt">induced</span> directly by the radiation, there is accumulating evidence for delayed genomic instability following X-ray exposure. We have investigated this phenomenon by studying delayed chromosomal instability in a hamster-human hybrid cell line by means of fluorescence in situ hybridization. We examined populations of metaphase cells several generations after expanding single-cell colonies that had survived 5 or 10 Gy of X rays. Delayed chromosomal instability, manifested as multiple rearrangements of human chromosome 4 in a background of hamster chromosomes, was observed in 29% of colonies surviving 5 Gy and in 62% of colonies surviving 10 Gy. A correlation of delayed chromosomal instability with delayed reproductive cell death, manifested as reduced plating efficiency in surviving clones, suggests a role for chromosome rearrangements in cytotoxicity. There were small differences in chromosome destabilization and plating efficiencies between cells irradiated with 5 or 10 Gy of X rays after a previous exposure to 10 Gy and cells irradiated only once. Cell clones showing delayed chromosomal instability had normal frequencies of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> formation, indicating that at this cytogenetic endpoint the chromosomal instability was not apparent. The types of chromosomal rearrangements observed suggest that chromosome fusion, followed by bridge breakage and refusion, contributes to the observed delayed chromosomal instability. Images PMID:8413263</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1258605-electric-field-induced-reversible-magnetization-switching-through-tuning-interfacial-exchange-bias-along-magnetic-easy-axis-multiferroic-laminates','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1258605-electric-field-induced-reversible-magnetization-switching-through-tuning-interfacial-exchange-bias-along-magnetic-easy-axis-multiferroic-laminates"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; et al</p> <p>2015-11-18</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shiftedmore » by up to |ΔHex|/Hex=8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |ΔHex|/Hc=67.5~125% in NiFe/FeMn/glass/PZN-PT and 30~38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Lastly, electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4649679','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4649679"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; Liu, Ming</p> <p>2015-01-01</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shifted by up to |∆Hex|/Hex = 8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |∆Hex|/Hc = 67.5 ~ 125% in NiFe/FeMn/glass/PZN-PT and 30 ~ 38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies. PMID:26576658</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMMM..373..120A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMMM..373..120A"><span id="translatedtitle">Interface <span class="hlt">induced</span> manipulation of perpendicular <span class="hlt">exchange</span> bias in Pt/Co/(Pt,Cr)/CoO 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>Akdoğan, N.; Yağmur, A.; Öztürk, M.; Demirci, E.; Öztürk, O.; Erkovan, M.</p> <p>2015-01-01</p> <p>Perpendicular <span class="hlt">exchange</span> bias has been manipulated by changing ferromagnetic film thickness and spacer layer in Pt/Co/(Pt,Cr)/CoO thin films. The <span class="hlt">exchange</span> bias characteristics, blocking temperature, and magnetization of thin films strongly depend on the spacer layer (Pt,Cr) between ferromagnetic and antiferromagnetic layers. While Pt/Co/Pt/CoO thin films show perpendicular <span class="hlt">exchange</span> bias, Pt/Co/Cr/CoO has <span class="hlt">exchange</span> bias with easy magnetization axis in the film plane. We have also observed very small hysteretic behavior from the hard axis magnetization curve of Pt/Co/Cr/CoO film. This can be attributed to misalignment of the sample or small perpendicular contribution from Pt/Co bottom interface. We have also investigated the temperature and spacer layer dependent <span class="hlt">exchange</span> bias properties of the samples. We observed higher HEB and HC for the thicker Co layer in the Pt/Co/Pt/CoO sample. In addition, onset of <span class="hlt">exchange</span> bias effect starts at much lower temperatures for Pt/Co/Cr/CoO thin film. This clearly shows that Cr spacer layer not only removes the perpendicular <span class="hlt">exchange</span> bias, but also reduces the <span class="hlt">exchange</span> interaction between Co and CoO and thus lowers the TB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApSS..371...67M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApSS..371...67M&link_type=ABSTRACT"><span id="translatedtitle">Sulfidation behavior of ZnFe2O4 roasted with pyrite: Sulfur <span class="hlt">inducing</span> and sulfur-oxygen interface <span class="hlt">exchange</span> mechanism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Min, Xiaobo; Zhou, Bosheng; Ke, Yong; Chai, Liyuan; Xue, Ke; Zhang, Chun; Zhao, Zongwen; Shen, Chen</p> <p>2016-05-01</p> <p>The sulfidation roasting behavior was analyzed in detail to reveal the reaction mechanism. Information about the sulfidation reaction, including phase transformation, ionic migration behavior and morphological change, were obtained by XRD, 57Fe Mossbauer spectroscopy, XPS and SEM analysis. The results showed that the sulfidation of zinc ferrite is a process of sulfur <span class="hlt">inducing</span> and sulfur-oxygen interface <span class="hlt">exchange</span>. This process can be divided into six stages: decomposition of FeS2, formation of the oxygen-deficient environment, migration of O2- <span class="hlt">induced</span> by S2(g), formation of ZnFe2O4-δ, migration of Fe2+ accompanied by the precipitation of ZnO, and the sulfur-oxygen interface <span class="hlt">exchange</span> reaction. The sulfidation products were zinc blende, wurtzite, magnetite and a fraction of zinc-bearing magnetite. These findings can provide theoretical support for controlling the process during which the recovery of Zn and Fe is achieved through the combined flotation-magnetic separation process.</p> </li> </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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4159693','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4159693"><span id="translatedtitle">Selective <span class="hlt">Chromatid</span> Segregation Mechanism Invoked For the Human Congenital Mirror Hand Movement Disorder Development by RAD51 Mutations: A Hypothesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Klar, Amar J. S.</p> <p>2014-01-01</p> <p>The vertebrate body plan externally is largely symmetrical across the midline but internal organs develop asymmetrically. The biological basis of asymmetric organ development has been investigated extensively for years, although the proposed mechanisms remain controversial. By comparison, the biological origin of external organs symmetry has not been extensively investigated. Bimanual hand control is one such external organs symmetry allowing independent motor control movements of both hands to a person. This gap in our knowledge is illustrated by the recent reports of heterozygous rad51 mutations causing mysterious symptoms of congenital mirror hand movement disorder (MM) in humans with 50% penetrance by an unknown mechanism. The analysis of mutations that vary symmetry or asymmetry could be exploited to decipher the mechanisms of laterality development. Here I present a hypothesis for explaining 50% penetrance of the rad51 mutation. The MM's origin is explained with the Somatic Strand-specific Imprinting and selective sister <span class="hlt">chromatid</span> Segregation (SSIS) hypothesis proposed originally as the mechanism of asymmetric cell division to promote visceral organs body plan laterality development in vertebrates. By hypothesis, random sister <span class="hlt">chromatid</span> segregation in mitosis occurs for a specific chromosome due to rad51/RAD51 constitution causing MM disorder development in 50% of subjects. PMID:25210500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12379012','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12379012"><span id="translatedtitle"><span class="hlt">Chromatid</span> gaps as a marker of mutagenic effect of environmental pollution in commensal and wild rodents of the Ural mountains.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gileva, E A</p> <p>2002-01-01</p> <p>It was supposed earlier that achromatic gaps could be used as markers of mutagenic effect of environmental pollution, especially under weaker clastogenic influences. The frequencies of true chromosome aberrations and those of <span class="hlt">chromatid</span> gaps were estimated in house mice and common voles from Uralian localities with various mutagenic potential of environment. Gaps and breaks were distinguished according to the CBIS system. In several localities, rodents displayed highly significant increase of the rates of cells with chromosome aberrations and with gaps as compared to the baseline values; only in the common vole, the P level for the gap increase was 0.056. The mean gap rate was correlated significantly with that of chromosome aberrations, not only with <span class="hlt">chromatid</span> breaks, but with the aberrations of other types, too. This parameter appears not to be more sensitive indicator of environmental mutagens than true chromosome mutations, when mutagenic impact is not very powerful, as it was in the localities investigated. The house mouse can be recommended as an effective test species for ecogenetic monitoring. PMID:12379012</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25210500','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25210500"><span id="translatedtitle">Selective <span class="hlt">chromatid</span> segregation mechanism invoked for the human congenital mirror hand movement disorder development by RAD51 mutations: a hypothesis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klar, Amar J S</p> <p>2014-01-01</p> <p>The vertebrate body plan externally is largely symmetrical across the midline but internal organs develop asymmetrically. The biological basis of asymmetric organ development has been investigated extensively for years, although the proposed mechanisms remain controversial. By comparison, the biological origin of external organs symmetry has not been extensively investigated. Bimanual hand control is one such external organs symmetry allowing independent motor control movements of both hands to a person. This gap in our knowledge is illustrated by the recent reports of heterozygous rad51 mutations causing mysterious symptoms of congenital mirror hand movement disorder (MM) in humans with 50% penetrance by an unknown mechanism. The analysis of mutations that vary symmetry or asymmetry could be exploited to decipher the mechanisms of laterality development. Here I present a hypothesis for explaining 50% penetrance of the rad51 mutation. The MM's origin is explained with the Somatic Strand-specific Imprinting and selective sister <span class="hlt">chromatid</span> Segregation (SSIS) hypothesis proposed originally as the mechanism of asymmetric cell division to promote visceral organs body plan laterality development in vertebrates. By hypothesis, random sister <span class="hlt">chromatid</span> segregation in mitosis occurs for a specific chromosome due to rad51/RAD51 constitution causing MM disorder development in 50% of subjects. PMID:25210500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4231310','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4231310"><span id="translatedtitle">Sgo1 recruits PP2A to chromosomes to ensure sister <span class="hlt">chromatid</span> bi-orientation during mitosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Eshleman, Heather D.; Morgan, David O.</p> <p>2014-01-01</p> <p>ABSTRACT Sister <span class="hlt">chromatid</span> bi-orientation on the mitotic spindle is essential for proper chromosome segregation. Defects in bi-orientation are sensed and corrected to prevent chromosome mis-segregation and aneuploidy. This response depends on the adaptor protein Sgo1, which associates with pericentromeric chromatin in mitosis. The mechanisms underlying Sgo1 function and regulation are unclear. Here, we show that Sgo1 is an anaphase-promoting complex/cyclosome (APC/C) substrate in budding yeast (Saccharomyces cerevisiae), and that its mitotic destruction depends on an unusual D-box-related sequence motif near its C-terminus. We find that the removal of Sgo1 from chromosomes before anaphase is not dependent on its destruction, but rather on other mechanisms responsive to tension between sister <span class="hlt">chromatids</span>. Additionally, we find that Sgo1 recruits the protein phosphatase 2A (PP2A) isoform containing Rts1 to the pericentromeric region prior to bi-orientation, and that artificial recruitment of Rts1 to this region of a single chromosome is sufficient to perform the function of Sgo1 on that chromosome. We conclude that in early mitosis, Sgo1 associates transiently with pericentromeric chromatin to promote bi-orientation, in large part by recruiting the Rts1 isoform of PP2A. PMID:25236599</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26724742','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26724742"><span id="translatedtitle">Treadmill exercise ameliorates ischemia-<span class="hlt">induced</span> brain edema while suppressing Na⁺/H⁺ <span class="hlt">exchanger</span> 1 expression.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nishioka, Ryutaro; Sugimoto, Kana; Aono, Hitomi; Mise, Ayano; Choudhury, Mohammed E; Miyanishi, Kazuya; Islam, Afsana; Fujita, Takahiro; Takeda, Haruna; Takahashi, Hisaaki; Yano, Hajime; Tanaka, Junya</p> <p>2016-03-01</p> <p>Exercise may be one of the most effective and sound therapies for stroke; however, the mechanisms underlying the curative effects remain unclear. In this study, the effects of forced treadmill exercise with electric shock on ischemic brain edema were investigated. Wistar rats were subjected to transient (90 min) middle cerebral artery occlusion (tMCAO). Eighty nine rats with substantially large ischemic lesions were evaluated using magnetic resonance imaging (MRI) and were randomly assigned to exercise and non-exercise groups. The rats were forced to run at 4-6m/s for 10 min/day on days 2, 3 and 4. Brain edema was measured on day 5 by MRI, histochemical staining of brain sections and tissue water content determination (n=7, each experiment). Motor function in some rats was examined on day 30 (n=6). Exercise reduced brain edema (P<0.05-0.001, varied by the methods) and ameliorated motor function (P<0.05). The anti-glucocorticoid mifepristone or the anti-mineralocorticoid spironolactone abolished these effects, but orally administered corticosterone mimicked the ameliorating effects of exercise. Exercise prevented the ischemia-<span class="hlt">induced</span> expression of mRNA encoding aquaporin 4 (AQP4) and Na(+)/H(+) <span class="hlt">exchangers</span> (NHEs) (n=5 or 7, P<0.01). Microglia and NG2 glia expressed NHE1 in the peri-ischemic region of rat brains and also in mixed glial cultures. Corticosterone at ~10nM reduced NHE1 and AQP4 expression in mixed glial and pure microglial cultures. Dexamethasone and aldosterone at 10nM did not significantly alter NHE1 and AQP4 expression. Exposure to a NHE inhibitor caused shrinkage of microglial cells. These results suggest that the stressful short-period and slow-paced treadmill exercise suppressed NHE1 and AQP4 expression resulting in the amelioration of brain edema at least partly via the moderate increase in plasma corticosterone levels. PMID:26724742</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23869070','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23869070"><span id="translatedtitle">Normal pulmonary gas <span class="hlt">exchange</span> efficiency and absence of exercise-<span class="hlt">induced</span> arterial hypoxemia in adults with bronchopulmonary dysplasia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lovering, Andrew T; Laurie, Steven S; Elliott, Jonathan E; Beasley, Kara M; Yang, Ximeng; Gust, Caitlyn E; Mangum, Tyler S; Goodman, Randall D; Hawn, Jerold A; Gladstone, Igor M</p> <p>2013-10-01</p> <p>Cardiopulmonary function is reduced in adults born very preterm, but it is unknown if this results in reduced pulmonary gas <span class="hlt">exchange</span> efficiency during exercise and, consequently, leads to reduced aerobic capacity in subjects with and without bronchopulmonary dysplasia (BPD). We hypothesized that an excessively large alveolar to arterial oxygen difference (AaDO2) and resulting exercise-<span class="hlt">induced</span> arterial hypoxemia (EIAH) would contribute to reduced aerobic fitness in adults born very preterm with and without BPD. Measurements of pulmonary function, lung volumes and diffusion capacity for carbon monoxide (DLco) were made at rest. Measurements of maximal oxygen consumption, peak workload, temperature- and tonometry-corrected arterial blood gases, and direct measure of hemoglobin saturation with oxygen (SaO2) were made preexercise and during cycle ergometer exercise in ex-preterm subjects ≤32-wk gestational age, with BPD (n = 12), without BPD (PRE; n = 12), and full term controls (CONT; n = 12) breathing room air. Both BPD and PRE had reduced pulmonary function and reduced DLco compared with CONT. The AaDO2 was not significantly different between groups, and there was no evidence of EIAH (SaO2 < 95% and/or AaDO2 ≥ 40 Torr) in any subject group preexercise or at any workload. Arterial O2 content was not significantly different between the groups preexercise or during exercise. However, peak power output was decreased in BPD and PRE subjects compared with CONT. We conclude that EIAH in adult subjects born very preterm with and without BPD does not likely contribute to the reduction in aerobic exercise capacity observed in these subjects. PMID:23869070</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26716266','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26716266"><span id="translatedtitle">Preparation of a Proton-<span class="hlt">Exchange</span> Me mbrane with -SO3H Group Based on Polyethylene and Poly(vinylidene fluoride) Film by Radiation-<span class="hlt">Induced</span> Graft Polymerization for Proton-<span class="hlt">Exchange</span> Fuel Cell.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Sang-Kyum; Lee, Yong-Sang; Koo, Kee-Kahb; Kim, Sang-Ho; Choi, Seong-Ho</p> <p>2015-09-01</p> <p>This paper reports the preparation of a proton-<span class="hlt">exchange</span> membrane (PEM) with sulfonic acid (-SO3H) groups based on polyethylene (PE) films and poly(vinylidene fluoride) (PVdF) films by the radiation-<span class="hlt">induced</span> graft polymerization (RIGP) of sodium styrene sulfonate (NaSS) in the presence of the polymerizable access agents, such as acrylic acid and pyrollidone in a methanol solution. A PEM with -SO3H based on PE and PVdF films were confirmed by ATR, XPS and contact angle measurements. The water uptake (%), graft yield (%), ion-<span class="hlt">exchange</span> content (mmol/g), and proton conductivity (S/cm), as well as the current density (mA/cm2), and power density (mW/cm) for PEM with -SO3H groups prepared by RIGP were evaluated. The PEM prepared with the -SO3H groups based on PE and PVdF films can be used as a proton-<span class="hlt">exchange</span> fuel cell membrane. PMID:26716266</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=312743','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/10487777','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10487777"><span id="translatedtitle">H(+)/solute-<span class="hlt">induced</span> intracellular acidification leads to selective activation of apical Na(+)/H(+) <span class="hlt">exchange</span> in human intestinal epithelial cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thwaites, D T; Ford, D; Glanville, M; Simmons, N L</p> <p>1999-09-01</p> <p>The intestinal absorption of many nutrients and drug molecules is mediated by ion-driven transport mechanisms in the intestinal enterocyte plasma membrane. Clearly, the establishment and maintenance of the driving forces - transepithelial ion gradients - are vital for maximum nutrient absorption. The purpose of this study was to determine the nature of intracellular pH (pH(i)) regulation in response to H(+)-coupled transport at the apical membrane of human intestinal epithelial Caco-2 cells. Using isoform-specific primers, mRNA transcripts of the Na(+)/H(+) <span class="hlt">exchangers</span> NHE1, NHE2, and NHE3 were detected by RT-PCR, and identities were confirmed by sequencing. The functional profile of Na(+)/H(+) <span class="hlt">exchange</span> was determined by a combination of pH(i), (22)Na(+) influx, and EIPA inhibition experiments. Functional NHE1 and NHE3 activities were identified at the basolateral and apical membranes, respectively. H(+)/solute-<span class="hlt">induced</span> acidification (using glycylsarcosine or beta-alanine) led to Na(+)-dependent, EIPA-inhibitable pH(i) recovery or EIPA-inhibitable (22)Na(+) influx at the apical membrane only. Selective activation of apical (but not basolateral) Na(+)/H(+) <span class="hlt">exchange</span> by H(+)/solute cotransport demonstrates that coordinated activity of H(+)/solute symport with apical Na(+)/H(+) <span class="hlt">exchange</span> optimizes the efficient absorption of nutrients and Na(+), while maintaining pH(i) and the ion gradients involved in driving transport. PMID:10487777</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22416178','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22416178"><span id="translatedtitle">Collision-<span class="hlt">induced</span> absorption with <span class="hlt">exchange</span> effects and anisotropic interactions: Theory and application to H{sub 2} − H{sub 2}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karman, Tijs; Avoird, Ad van der; Groenenboom, Gerrit C.</p> <p>2015-02-28</p> <p>We discuss three quantum mechanical formalisms for calculating collision-<span class="hlt">induced</span> absorption spectra. First, we revisit the established theory of collision-<span class="hlt">induced</span> absorption, assuming distinguishable molecules which interact isotropically. Then, the theory is rederived incorporating <span class="hlt">exchange</span> effects between indistinguishable molecules. It is shown that the spectrum can no longer be written as an incoherent sum of the contributions of the different spherical components of the dipole moment. Finally, we derive an efficient method to include the effects of anisotropic interactions in the computation of the absorption spectrum. This method calculates the dipole coupling on-the-fly, which allows for the uncoupled treatment of the initial and final states without the explicit reconstruction of the many-component wave functions. The three formalisms are applied to the collision-<span class="hlt">induced</span> rotation-translation spectra of hydrogen molecules in the far-infrared. Good agreement with experimental data is obtained. Significant effects of anisotropic interactions are observed in the far wing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4861913','PMC'); return false;" href="http://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('http://adsabs.harvard.edu/abs/2016NatSR...625644S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...625644S"><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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiraishi, Junya; Miyato, Naoaki; Matsunaga, Go</p> <p>2016-05-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27160346','PUBMED'); return false;" href="http://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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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('http://www.osti.gov/scitech/biblio/22273941','SCIGOV-STC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/8488876','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8488876"><span id="translatedtitle">Recombinant chromosome 9 possibly derived from breakage and reunion of sister <span class="hlt">chromatids</span> within a paracentric inversion loop.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Phelan, M C; Stevenson, R E; Anderson, E V</p> <p>1993-05-15</p> <p>Chromosomally unbalanced offspring resulting from the recombination of parental paracentric inversions are uncommon. We report on a 20-month-old boy with a partial duplication of 9p due to the recombination of a paternal paracentric inversion. The patient's recombinant chromosome was designated rec(9)(p13-->p24::p12-->p24::p12-->qter). The patient's father and paternal aunt have a paracentric inversion of chromosome 9:inv(9)(p13p24). Although several mechanisms have been proposed to explain the chromosome imbalance generated from paracentric inversions, none of the previously described mechanisms can account for the structure of the recombinant chromosome observed in the propositus. We propose an unusual mechanism of formation involving breakage and unequal reunion of sister <span class="hlt">chromatids</span> within the inversion loop to explain the structure of the patient's recombinant chromosome. PMID:8488876</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818255','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818255"><span id="translatedtitle">Peroxisome Proliferator–Activated Receptor α Protects Renal Tubular Cells from Gentamicin-<span class="hlt">Induced</span> Apoptosis via Upregulating Na+/H+ <span class="hlt">Exchanger</span> NHE1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Cheng-Hsien; Chen, Tso-Hsiao; Wu, Mei-Yi; Chen, Jia-Rung; Hong, Li-Yu; Zheng, Cai-Mei; Chiu, I-Jen; Lin, Yuh-Feng; Hsu, Yung-Ho</p> <p>2015-01-01</p> <p>Peroxisome proliferator–activated receptor (PPAR)-α is a transcription factor that has been reported to inhibit gentamicin-<span class="hlt">induced</span> apoptosis in renal tubular cells. However, the antiapoptotic mechanism of PPARα is still unknown. In this study, we found that PPARα overexpression <span class="hlt">induced</span> Na+/H+ <span class="hlt">exchanger</span>-1 (NHE1) expression in the rat renal tubular cells NRK-52E. Beraprost, a PPARα ligand, also increased NHE1 expression in the renal tubules in normal mice, but not in PPARα knockout mice. Chromatin immunoprecipitation assays revealed that two PPARα binding elements were located in the rat NHE1 promoter region. Na+/H+ <span class="hlt">exchanger</span> activity also increased in the PPARα-overexpressed cells. Flow cytometry showed that the PPARα-overexpressed cells were resistant to apoptosis-<span class="hlt">induced</span> shrinkage. Cariporide, a selective NHE1 inhibitor, inhibited the antiapoptotic effect of PPARα in the gentamicin-treated cells. The interaction between NHE1 and ezrin/radixin/moesin (ERM) and between ERM and phosphatidylinositol 4,5-bisphosphate in the PPARα-overexpressed cells was more than in the control cells. ERM short interfering RNA (siRNA) transfection inhibited the PPARα-<span class="hlt">induced</span> antiapoptotic effect. PPARα overexpression also increased the phosphoinositide 3-kinase (PI3K) expression, which is dependent on NHE1 activity. Increased PI3K further increased the phosphorylation of the prosurvival kinase Akt in the PPARα-overexpressed cells. Wortmannin, a PI3K inhibitor, inhibited PPARα-<span class="hlt">induced</span> Akt activity and the antiapoptotic effect. We conclude that PPARα <span class="hlt">induces</span> NHE1 expression and then recruits ERM to promote PI3K/Akt-mediated cell survival in renal tubular cells. The application of PPARα activation reduces the nephrotoxicity of gentamicin and may expand the clinical use of gentamicin. PMID:26623927</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26477560','PUBMED'); return false;" href="http://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="http://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. PMID:26477560</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1258605','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1258605"><span id="translatedtitle">Electric field <span class="hlt">induced</span> reversible 180° magnetization switching through tuning of interfacial <span class="hlt">exchange</span> bias along magnetic easy-axis in multiferroic laminates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xue, Xu; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Zhang, Yijun; Ren, Wei; Ren, Tao; Yang, Xi; Nan, Tianxiang; Sun, Nian X.; Liu, Ming</p> <p>2015-11-18</p> <p>E-field control of interfacial <span class="hlt">exchange</span> coupling and deterministic switching of magnetization have been demonstrated in two sets of ferromagnetic(FM)/antiferromagnetic(AFM)/ferroelectric(FE) multiferroic heterostructures, including NiFe/NiCoO/glass/PZN-PT (011) and NiFe/FeMn/glass/PZN-PT (011). We designed this experiment to achieve <span class="hlt">exchange</span> bias tuning along the magnetic easy axis, which is critical for realizing reversible 180° magnetization deterministic switching at zero or small magnetic bias. Strong <span class="hlt">exchange</span> coupling were established across AFM-FM interfaces, which plays an important role in voltage control of magnetization switching. Through the competition between the E-field <span class="hlt">induced</span> uniaxial anisotropy in ferromagnetic layer and unidirectional anisotropy in antiferromagnetic layer, the <span class="hlt">exchange</span> bias was significantly shifted by up to |ΔH<sub>ex</sub>|/H<sub>ex</sub>=8% in NiFe/FeMn/glass/PZN-PT (011) and 13% in NiFe/NiCoO/glass/PZN-PT (011). In addition, the square shape of the hysteresis loop, as well as a strong shape tunability of |ΔH<sub>ex</sub>|/H<sub>c</sub>=67.5~125% in NiFe/FeMn/glass/PZN-PT and 30~38% in NiFe/NiCoO/glass/PZN-PT were achieved, which lead to a near 180° magnetization switching. Lastly, electrical tuning of interfacial <span class="hlt">exchange</span> coupling in FM/AFM/FE systems paves a new way for realizing magnetoelectric random access memories and other memory technologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3516844','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3516844"><span id="translatedtitle">Cdc42 and the Guanine Nucleotide <span class="hlt">Exchange</span> Factors Ect2 and Trio Mediate Fn14-<span class="hlt">Induced</span> Migration and Invasion of Glioblastoma Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fortin, Shannon P.; Ennis, Matthew J.; Schumacher, Cassie A.; Zylstra-Diegel, Cassandra R.; Williams, Bart O.; Ross, Julianna T.D.; Winkles, Jeffrey A.; Loftus, Joseph C.; Symons, Marc H.; Tran, Nhan L.</p> <p>2012-01-01</p> <p>Malignant glioblastomas are characterized by their ability to infiltrate into normal brain. We previously reported that binding of the multifunctional cytokine TNF-like weak <span class="hlt">inducer</span> of apoptosis (TWEAK) to its receptor fibroblast growth factor–<span class="hlt">inducible</span> 14 (Fn14) <span class="hlt">induces</span> glioblastoma cell invasion via Rac1 activation. Here, we show that Cdc42 plays an essential role in Fn14-mediated activation of Rac1. TWEAK-treated glioma cells display an increased activation of Cdc42, and depletion of Cdc42 using siRNA abolishes TWEAK-<span class="hlt">induced</span> Rac1 activation and abrogates glioma cell migration and invasion. In contrast, Rac1 depletion does not affect Cdc42 activation by Fn14, showing that Cdc42 mediates TWEAK-stimulated Rac1 activation. Furthermore, we identified two guanine nucleotide <span class="hlt">exchange</span> factors (GEF), Ect2 and Trio, involved in TWEAK-<span class="hlt">induced</span> activation of Cdc42 and Rac1, respectively. Depletion of Ect2 abrogates both TWEAK-<span class="hlt">induced</span> Cdc42 and Rac1 activation, as well as subsequent TWEAK-Fn14–directed glioma cell migration and invasion. In contrast, Trio depletion inhibits TWEAK-<span class="hlt">induced</span> Rac1 activation but not TWEAK-<span class="hlt">induced</span> Cdc42 activation. Finally, inappropriate expression of Fn14 or Ect2 in mouse astrocytes in vivo using an RCAS vector system for glial-specific gene transfer in G-tva transgenic mice <span class="hlt">induces</span> astrocyte migration within the brain, corroborating the in vitro importance of the TWEAK-Fn14 signaling cascade in glioblastoma invasion. Our results suggest that the TWEAK-Fn14 signaling axis stimulates glioma cell migration and invasion through two GEF-GTPase signaling units, Ect2-Cdc42 and Trio-Rac1. Components of the Fn14-Rho GEF-Rho GTPase signaling pathway present innovative drug targets for glioma therapy. PMID:22571869</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12740420','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12740420"><span id="translatedtitle">An important role for the Na+-Ca2+ <span class="hlt">exchanger</span> in the decrease in cytosolic Ca2+ concentration <span class="hlt">induced</span> by isoprenaline in the porcine coronary artery.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yamanaka, Jun; Nishimura, Junji; Hirano, Katsuya; Kanaide, Hideo</p> <p>2003-06-01</p> <p>The role of the Na+-Ca2+ <span class="hlt">exchanger</span> (NCX) in the mechanism of the isoprenaline (Iso)-<span class="hlt">induced</span> vasorelaxation was investigated by simultaneously monitoring the intracellular Ca2+ concentration ([Ca2+]i) and tension of fura-2-loaded medial strips of porcine coronary arteries. Normal physiological salt solution (PSS) contained 137.3 mM Na+ and 5.9 mM K+. During the sustained phase of contraction, Iso <span class="hlt">induced</span> only a transient decrease in [Ca2+]i when contraction was <span class="hlt">induced</span> by depolarization with 118 mM K+ solution containing 25.2 mM Na+. When contraction was <span class="hlt">induced</span> with 30 mM K+ in PSS containing 113.2 mM Na+, Iso <span class="hlt">induced</span> a sustained decrease in [Ca2+]i, whereas in contractions <span class="hlt">induced</span> by 30 mM K+ in a low Na+ (25.2 mM Na+) PSS, Iso transiently decreased [Ca2+]i. Replacement of Ca2+ with Ba2+ (which cannot be extruded by the Ca2+ pumps but can be extruded through the NCX) resulted in decreased [Ba2+]i <span class="hlt">induced</span> by Iso in normal but not in low Na+ PSS. On the other hand, Iso <span class="hlt">induced</span> a sustained decrease in [Ca2+]i when strips were pre-contracted by U46619, a thromboxane A2 analogue, in PSS. Various types of K+ channel blockers (iberiotoxin, 4-aminopyridine, apamin or glibenclamide) or combinations of these blockers failed to completely inhibit the Iso-<span class="hlt">induced</span> decreases in [Ca2+]i and tension. However, Iso-<span class="hlt">induced</span> sustained decreases in [Ca2+]i during the contraction <span class="hlt">induced</span> by U46619 were greatly inhibited in a low Na+ PSS. The Iso-<span class="hlt">induced</span> decrease in tension during contraction by U46619 was greatly inhibited by 2',4'-dichlorobenzamil, a forward- and reverse-mode NCX inhibitor, but not by ouabain, a selective inhibitor of Na+,K+-ATPase. These results indicate that the NCX is involved in the Iso-<span class="hlt">induced</span> reduction of [Ca2+]i and tension of the porcine coronary arterial smooth muscle. PMID:12740420</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010MeScT..21k5405S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010MeScT..21k5405S"><span id="translatedtitle">Application of planar laser-<span class="hlt">induced</span> fluorescence measurement techniques to study the heat transfer characteristics of parallel-plate heat <span class="hlt">exchangers</span> in thermoacoustic devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Lei; Mao, Xiaoan; Jaworski, Artur J.</p> <p>2010-11-01</p> <p>This paper describes the development of an experimental arrangement and the application of acetone-based planar laser-<span class="hlt">induced</span> fluorescence (PLIF) measurement techniques to study the unsteady characteristics of heat transfer processes in the parallel-plate heat <span class="hlt">exchangers</span> of thermoacoustic devices. The experimental rig is a quarter-wavelength acoustic resonator where a standing wave imposes oscillatory flow conditions. Two mock-up heat <span class="hlt">exchangers</span>, 'hot' and 'cold', have their fins kept at constant temperatures by electrical heating and water cooling, respectively. A purpose-designed acetone tracer seeding mechanism is used for PLIF temperature measurement. Acetone concentration is optimized from the viewpoint of PLIF signal intensity. Two-dimensional temperature distributions in the gas surrounding the heat <span class="hlt">exchanger</span> plates, as a function of phase angle in the acoustic cycle, are obtained. Local and global (instantaneous and cycle-averaged) heat flux values on the fin surface are estimated and used to obtain the dependence of the space-cycle averaged Nusselt versus Reynolds number. Measurement uncertainties are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/268256','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/268256"><span id="translatedtitle">Elastomer-<span class="hlt">induced</span> crevice corrosion and stress corrosion cracking of stainless steel heat <span class="hlt">exchanger</span> plates in sour amine service</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hay, M.G.; Baron, J.J.; Moffat, T.A.</p> <p>1996-08-01</p> <p>Types S31600 and S31254 stainless steel heat <span class="hlt">exchanger</span> plates have suffered crevice corrosion and stress corrosion cracking under gaskets in rich amine service in a sour gas plant. The gasket material, ethylene-propylene-diene monomer (EPDM), has been used successfully for many years at other sour gas plants. Laboratory testing has duplicated the corrosion observed and shown that the mechanism is synergistic sulfide-halide attack. The use of a bromine plus chlorine-activated curing system for the EPDM rubber gaskets provided the necessary halides. Laboratory testing identified some nickel-based superalloys which were resistant to this corrosion and also demonstrated that essentially halogen-free, peroxide-cured EPDM gaskets do not cause attack of S31600 or S31254. The heat <span class="hlt">exchanger</span> packs were replaced with S31600 plates and peroxide-cured EPDM gaskets having a specified total halogen concentration of 200 ppm maximum. Field operating experience has been excellent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1210146-exchange-bias-effect-au-fe3o4-dumbbell-nanoparticles-induced-charge-transfer-from-gold','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1210146-exchange-bias-effect-au-fe3o4-dumbbell-nanoparticles-induced-charge-transfer-from-gold"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe3O4 dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; et al</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatchmore » between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1240279','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1240279"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe3O4 dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Feygenson, Mikhail; Bauer, John C.; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S.; Beyer, Kevin A.; Dai, Sheng</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron-scattering, synchrotron x-ray diffraction, and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into the FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed, presumably across the interface to accommodate an excess of oxygen released during the reduction of magnetite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3733826','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3733826"><span id="translatedtitle">Assessment of gene expression of intracellular calcium channels, pumps and <span class="hlt">exchangers</span> with epidermal growth factor-<span class="hlt">induced</span> epithelial-mesenchymal transition in a breast cancer cell line</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Background Epithelial-mesenchymal transition (EMT) is a process implicated in cancer metastasis that involves the conversion of epithelial cells to a more mesenchymal and invasive cell phenotype. In breast cancer cells EMT is associated with altered store-operated calcium influx and changes in calcium signalling mediated by activation of cell surface purinergic receptors. In this study, we investigated whether MDA-MB-468 breast cancer cells <span class="hlt">induced</span> to undergo EMT exhibit changes in mRNA levels of calcium channels, pumps and <span class="hlt">exchangers</span> located on intracellular calcium storing organelles, including the Golgi, mitochondria and endoplasmic reticulum (ER). Methods Epidermal growth factor (EGF) was used to <span class="hlt">induce</span> EMT in MDA-MB-468 breast cancer cells. Serum-deprived cells were treated with EGF (50 ng/mL) for 12 h and gene expression was assessed using quantitative RT-PCR. Results and conclusions These data reveal no significant alterations in mRNA levels of the Golgi calcium pump secretory pathway calcium ATPases (SPCA1 and SPCA2), or the mitochondrial calcium uniporter (MCU) or Na+/Ca2+ <span class="hlt">exchanger</span> (NCLX). However, EGF-<span class="hlt">induced</span> EMT was associated with significant alterations in mRNA levels of specific ER calcium channels and pumps, including (sarco)-endoplasmic reticulum calcium ATPases (SERCAs), and inositol 1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor (RYR) calcium channel isoforms. The most prominent change in gene expression between the epithelial and mesenchymal-like states was RYR2, which was enriched 45-fold in EGF-treated MDA-MB-468 cells. These findings indicate that EGF-<span class="hlt">induced</span> EMT in breast cancer cells may be associated with major alterations in ER calcium homeostasis. PMID:23890218</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6654578','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6654578"><span id="translatedtitle">Repair of chromosome damage <span class="hlt">induced</span> by X-irradiation during G2 phase in a line of normal human fibroblasts and its malignant derivative</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parshad, R.; Gantt, R.; Sanford, K.K.; Jones, G.M.; Tarone, R.E.</p> <p>1982-08-01</p> <p>A line of normal human skin fibroblasts (KD) differed from its malignant derivative (HUT-14) in the extent of cytogenetic damage <span class="hlt">induced</span> by X-irradiation during G2 phase. Malignant cells had significantly more <span class="hlt">chromatid</span> breaks and gaps after exposure to 25, 50, or 100 rad. The gaps may represent single-strand breaks. Results from alkaline elution of cellular DNA immediately after irradiation showed that the normal and malignant cells in asynchronous population were equally sensitive to DNA single-strand breakage by X-irradiation. Caffeine or beta-cytosine arabinoside (ara-C), inhibitors of DNA repair, when added directly following G2 phase exposure, significantly increased the incidence of radiation-<span class="hlt">induced</span> <span class="hlt">chromatid</span> damage in the normal cells. In contrast, similar treatment of the malignant cells had little influence. Ara-C differed from caffeine in its effects; whereas both agents increased the frequency of <span class="hlt">chromatid</span> breaks and gaps, only ara-C increased the frequency of gaps to the level observed in the irradiated malignant cells. Addition of catalase, a scavenger of the derivative free hydroxyl radical (.OH), to the cultures of malignant cells before, during, and following irradiation significantly reduced the <span class="hlt">chromatid</span> damage; and catalase prevented formation of <span class="hlt">chromatid</span> gaps. The DNA damage <span class="hlt">induced</span> by X-ray during G2 phase in the normal KD cells was apparently repaired by a caffeine- and ara-C-sensitive mechanism(s) that was deficient or absent in their malignant derivatives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21143909','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21143909"><span id="translatedtitle">Involvement of Na{sup +}/H{sup +} <span class="hlt">exchanger</span> 1 in advanced glycation end products-<span class="hlt">induced</span> proliferation of vascular smooth muscle cell</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu Shujin; Song Tao; Zhou Shouhong; Liu Yuhui; Chen Gengrong; Huang Ningjiang; Liu Liying</p> <p>2008-10-24</p> <p>In this present study, we examined the role of Na{sup +}/H{sup +} <span class="hlt">exchanger</span> 1 (NHE1) in the cultured rat vascular smooth muscle cell (VSMC) proliferation <span class="hlt">induced</span> by advanced glycation end products (AGEs). AGEs significantly increased the [{sup 3}H] thymidine incorporation of VSMC. Cariporide, an NHE1 inhibitor, dose-dependently attenuated the AGEs-<span class="hlt">induced</span> increase in cell DNA synthesis. Thus the effect of AGEs on NHE1 activity was next examined. The cariporide-dependent intracellular pH (pH{sub i}) was significantly increased after 24 h exposure to AGEs (10 {mu}g/ml). The direct AGEs-<span class="hlt">induced</span> NHE1 activation was measured by the Na{sup +}-dependent intracellular pH recovery from intracellular acidosis. AGEs can increase the NHE1 activity in a time- and concentration-dependent manner. Inhibition of either the receptor for AGEs (RAGE) by anti-RAGE or mitogen-activated protein kinases (MAPK) by PD98059 reversed the effect of AGEs on NHE1 activity. Reverse transcription (RT)-PCR analysis revealed that AGEs dose-dependently increased NHE1 mRNA at 24 h. These findings demonstrate NHE1 is required for in AGEs-<span class="hlt">induced</span> proliferation of VSMC, and AGEs increase NHE1 activity via the MAPK pathway.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3387235','PMC'); return false;" href="http://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('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/2014APS..MARG55001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARG55001M"><span id="translatedtitle">Broken lattice-symmetry influence on electronic anisotropy and interface <span class="hlt">exchange-coupling-induced</span> ferromagnetic state in TI thin films and heterostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moodera, Jagadeesh</p> <p>2014-03-01</p> <p><span class="hlt">Inducing</span> an <span class="hlt">exchange</span> gap locally on the Dirac surface states of a topological insulator (TI) is ideal for observing the predicted unique features such as the quantized topological magnetoelectric effect, half-integer quantized Hall effect, as well as to con?ne Majorana fermions. Our work experimentally demonstrated the proximity-<span class="hlt">induced</span> interface ferromagnetism in a heterostructure combining a ferromagnetic insulator EuS layer with Bi2Se3, without introducing defects. An <span class="hlt">exchange</span> gap was observed to be <span class="hlt">induced</span> on the surface of the TI. Extensive magnetic and magneto-transport (magnetoresistance and anomalous Hall effect) investigation of the heterostructures, including synchrotron interfacial (XAS and XMCD measurements) studies have shown the emergence of a ferromagnetic phase in TI, which is a step forward to unveiling the above exotic properties. Also, to understand the intrinsic properties of TI it is necessary to correlate structure with the exotic electronic properties as well as interaction with other materials. Molecular beam epitaxy (MBE) ideally allows us to engineer the system whereas using synchrotron and electron diffraction based experimental techniques helps us to investigate with atomic resolution. We will elucidate our studies on well-defined TI films and heterostructure, and the role of imperfections on the symmetry of the material that leads to internal atomic ordering by the decoration of the defects. Charge transport and mobility are seen to relate with film growth strain and relaxation as well as display strong directional dependence on the defect geometry. Work done in collaboration with Peng Wei, Ferhat Katmis and others. NSF and ONR grants supported this work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1567390','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1567390"><span id="translatedtitle">Role of DNA repair inhibition in lead- and cadmium-<span class="hlt">induced</span> genotoxicity: a review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hartwig, A</p> <p>1994-01-01</p> <p>Compounds of lead and cadmium have been shown to be carcinogenic to humans and experimental animals. However, the underlying mechanisms are still not understood. In mammalian cells in culture, lead(II) is weakly mutagenic after long incubation times and generates DNA strand breaks only after treatment with high, toxic doses. Cadmium(II) <span class="hlt">induces</span> DNA strand breaks and chromosomal aberrations, but its mutagenic potential is rather weak. However, both metals exert pronounced indirect genotoxic effects. Lead(II) is comutagenic towards UV and N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and enhances the number of UV-<span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in V79 Chinese hamster cells. With regard to DNA repair, lead(II) causes an accumulation of DNA strand breaks after UV-irradiation in HeLa cells, indicating an interference with the polymerization or ligation step in excision repair. Cadmium(II) enhances the mutagenicity of UV light in V79 Chinese hamster cells and an increased sensitivity toward UV light is observed in various rodent and human cell lines. Furthermore, an inhibition of unscheduled DNA synthesis after UV-irradiation and a partial inhibition of the removal of UV-<span class="hlt">induced</span> DNA lesions has been shown. For both metals, the indirect genotoxic effects are observed at low, nontoxic concentrations, suggesting that an interference with DNA repair processes may be predominant at biologically relevant concentrations. This might also explain the conflicting results of epidemiological studies obtained for both metals. Possible mechanisms of repair inhibition are discussed. PMID:7843136</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2703808','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2703808"><span id="translatedtitle">Regulation of the Drosophila Enhancer of split and invected-engrailed Gene Complexes by Sister <span class="hlt">Chromatid</span> Cohesion Proteins</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sahota, Gurmukh; Siddiqui, Akbar M.; Schwartz, Yuri B.; Kahn, Tatyana G.; Pirrotta, Vincenzo; Gause, Maria; Dorsett, Dale</p> <p>2009-01-01</p> <p>The cohesin protein complex was first recognized for holding sister <span class="hlt">chromatids</span> together and ensuring proper chromosome segregation. Cohesin also regulates gene expression, but the mechanisms are unknown. Cohesin associates preferentially with active genes, and is generally absent from regions in which histone H3 is methylated by the Enhancer of zeste [E(z)] Polycomb group silencing protein. Here we show that transcription is hypersensitive to cohesin levels in two exceptional cases where cohesin and the E(z)-mediated histone methylation simultaneously coat the entire Enhancer of split and invected-engrailed gene complexes in cells derived from Drosophila central nervous system. These gene complexes are modestly transcribed, and produce seven of the twelve transcripts that increase the most with cohesin knockdown genome-wide. Cohesin mutations alter eye development in the same manner as increased Enhancer of split activity, suggesting that similar regulation occurs in vivo. We propose that cohesin helps restrain transcription of these gene complexes, and that deregulation of similarly cohesin-hypersensitive genes may underlie developmental deficits in Cornelia de Lange syndrome. PMID:19587787</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3376262','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3376262"><span id="translatedtitle">Multiple meiotic errors caused by predivision of <span class="hlt">chromatids</span> in women of advanced maternal age undergoing in vitro fertilisation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Handyside, Alan H; Montag, Markus; Magli, M Cristina; Repping, Sjoerd; Harper, Joyce; Schmutzler, Andreas; Vesela, Katerina; Gianaroli, Luca; Geraedts, Joep</p> <p>2012-01-01</p> <p>Chromosome aneuploidy is a major cause of pregnancy loss, abnormal pregnancy and live births following both natural conception and in vitro fertilisation (IVF) and increases exponentially with maternal age in the decade preceding the menopause. Molecular genetic analysis following natural conception and spontaneous miscarriage demonstrates that trisomies arise mainly in female meiosis and particularly in the first meiotic division. Here, we studied copy number gains and losses for all chromosomes in the two by-products of female meiosis, the first and second polar bodies, and the corresponding zygotes in women of advanced maternal age undergoing IVF, using microarray comparative genomic hybridisation (array CGH). Analysis of the segregation patterns underlying the copy number changes reveals that premature predivision of <span class="hlt">chromatids</span> rather than non-disjunction of whole chromosomes causes almost all errors in the first meiotic division and unlike natural conception, over half of aneuploidies result from errors in the second meiotic division. Furthermore, most abnormal zygotes had multiple aneuploidies. These differences in the aetiology of aneuploidy in IVF compared with natural conception may indicate a role for ovarian stimulation in perturbing meiosis in ageing oocytes. PMID:22317970</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4282573','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4282573"><span id="translatedtitle">SNW1 enables sister <span class="hlt">chromatid</span> cohesion by mediating the splicing of sororin and APC2 pre-mRNAs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van der Lelij, Petra; Stocsits, Roman R; Ladurner, Rene; Petzold, Georg; Kreidl, Emanuel; Koch, Birgit; Schmitz, Julia; Neumann, Beate; Ellenberg, Jan; Peters, Jan-Michael</p> <p>2014-01-01</p> <p>Although splicing is essential for the expression of most eukaryotic genes, inactivation of splicing factors causes specific defects in mitosis. The molecular cause of this defect is unknown. Here, we show that the spliceosome subunits SNW1 and PRPF8 are essential for sister <span class="hlt">chromatid</span> cohesion in human cells. A transcriptome-wide analysis revealed that SNW1 or PRPF8 depletion affects the splicing of specific introns in a subset of pre-mRNAs, including pre-mRNAs encoding the cohesion protein sororin and the APC/C subunit APC2. SNW1 depletion causes cohesion defects predominantly by reducing sororin levels, which causes destabilisation of cohesin on DNA. SNW1 depletion also reduces APC/C activity and contributes to cohesion defects indirectly by delaying mitosis and causing “cohesion fatigue”. Simultaneous expression of sororin and APC2 from intron-less cDNAs restores cohesion in SNW1-depleted cells. These results indicate that the spliceosome is required for mitosis because it enables expression of genes essential for cohesion. Our transcriptome-wide identification of retained introns in SNW1- and PRPF8-depleted cells may help to understand the aetiology of diseases associated with splicing defects, such as retinosa pigmentosum and cancer. PMID:25257309</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20591439','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20591439"><span id="translatedtitle">Resonance elastic light scattering (RELS) spectroscopy of fast non-Langmuirian ligand-<span class="hlt">exchange</span> in glutathione-<span class="hlt">induced</span> gold nanoparticle assembly.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stobiecka, Magdalena; Coopersmith, Kaitlin; Hepel, Maria</p> <p>2010-10-01</p> <p>The interactions of a biomolecule glutathione (GSH) with citrate-capped gold nanoparticles (AuNP) have been investigated to evaluate the viability of a rapid GSH-capture by gold nanoparticle carriers, as a model system for applications ranging from designing nanoparticle-enhanced functional biosensor interfaces to nanomedicine. The measurements, performed using resonance elastic light scattering (RELS) spectroscopy, have shown a strong dependence of GSH-<span class="hlt">induced</span> scattering cross-section on gold nanoparticle size. A large increase in RELS intensity after injection of GSH, in a short reaction time (tau=60 s), has been observed for small AuNP (5nm dia.) and ascribed to the fast ligand-<span class="hlt">exchange</span> followed by AuNP assembly. The unexpected non-Langmuirian concentration dependence of scattering intensity for AuNP (5 nm) indicates on a 2D nucleation and growth mechanism of the ligand-<span class="hlt">exchange</span> process. The ligand-<span class="hlt">exchange</span> and small nanoparticle ensemble formation followed by relaxation have been observed in long term (10 h) monitoring of GSH-AuNP interactions by RELS. The results of molecular dynamics and quantum mechanical calculations corroborate the mechanism of the formation of hydrogen-bonded GSH-linkages and interparticle interactions and show that the assembly is driven by multiple H-bonding between GSH-capped AuNP and electrostatic zwitterionic interactions. The RELS spectroscopy has been found as a very sensitive tool for studying interparticle interactions. The application of RELS can be expanded to monitor reactivities and assembly of other monolayer-protected metal clusters, especially in very fast processes which cannot be followed by other techniques. PMID:20591439</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27029886','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27029886"><span id="translatedtitle">Orbitally <span class="hlt">induced</span> hierarchy of <span class="hlt">exchange</span> interactions in the zigzag antiferromagnetic state of honeycomb silver delafossite Ag3Co2SbO6.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zvereva, E A; Stratan, M I; Ushakov, A V; Nalbandyan, V B; Shukaev, I L; Silhanek, A V; Abdel-Hafiez, M; Streltsov, S V; Vasiliev, A N</p> <p>2016-04-25</p> <p>We report the revised crystal structure, static and dynamic magnetic properties of quasi-two dimensional honeycomb-lattice silver delafossite Ag3Co2SbO6. The magnetic susceptibility and specific heat data are consistent with the onset of antiferromagnetic long range order at low temperatures with Néel temperature TN ∼ 21.2 K. In addition, the magnetization curves revealed a field-<span class="hlt">induced</span> (spin-flop type) transition below TN in moderate magnetic fields. The GGA+U calculations show the importance of the orbital degrees of freedom, which maintain a hierarchy of <span class="hlt">exchange</span> interaction in the system. The strongest antiferromagnetic <span class="hlt">exchange</span> coupling was found in the shortest Co-Co pairs and is due to direct and superexchange interaction between the half-filled xz + yz orbitals pointing directly to each other. The other four out of six nearest neighbor <span class="hlt">exchanges</span> within the cobalt hexagon are suppressed, since for these bonds the active half-filled orbitals turned out to be parallel and do not overlap. The electron spin resonance (ESR) spectra reveal a broad absorption line attributed to the Co(2+) ion in an octahedral coordination with an average effective g-factor g = 2.40 ± 0.05 at room temperature and show strong divergence of the ESR parameters below ∼150 K, which implies an extended region of short-range correlations. Based on the results of magnetic and thermodynamic studies in applied fields, we propose a magnetic phase diagram for the new honeycomb-lattice delafossite. PMID:27029886</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4915239','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4915239"><span id="translatedtitle">miR-185 inhibits endoplasmic reticulum stress-<span class="hlt">induced</span> apoptosis by targeting Na+/H+ <span class="hlt">exchanger</span>-1 in the heart</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, Jin Ock; Kwon, Eun Jeong; Song, Dong Woo; Lee, Jong Sub; Kim, Do Han</p> <p>2016-01-01</p> <p>Prolonged ER stress (ERS) can be associated with the induction of apoptotic cell death in various heart diseases. In this study, we searched for microRNAs affecting ERS in the heart using in silico and in vitro methods. We found that miR-185 directly targets the 3′-untranslated region of Na+/H+ <span class="hlt">exchanger</span>-1 (NHE-1), a protein involved in ERS. Cardiomyocyte ERS-triggered apoptosis <span class="hlt">induced</span> by 100 ng/ml tunicamycin (TM) or 1 μM thapsigargin (TG), ERS <span class="hlt">inducers</span>, was significantly reduced by miR-185 overexpression. Protein expression of pro-apoptotic markers such as CCAAT/enhancer-binding protein homologous protein (CHOP) and cleaved-caspase-3 was also markedly reduced by miR-185 in a dose-dependent manner. Cariporide (20 μM), a pharmacological inhibitor of NHE-1, also attenuated ERS-<span class="hlt">induced</span> apoptosis in cardiomyocytes and CHOP protein expression, suggesting that NHE-1 plays an important role in ERS-associated apoptosis in cardiomyocytes. Collectively, the present results demonstrate that miR-185 is involved in cardio-protection against ERS-mediated apoptotic cell death. [BMB Reports 2016; 49(4): 208-213] PMID:26521941</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JEMat..44.1377N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JEMat..44.1377N"><span id="translatedtitle">Effect of Diffusion Control Layer on Reverse Al-<span class="hlt">Induced</span> Layer <span class="hlt">Exchange</span> Process for High-Quality Ge/Al/Glass Structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakazawa, K.; Toko, K.; Suemasu, T.</p> <p>2015-05-01</p> <p>Fabricating large-grained polycrystalline Ge (poly-Ge) thin films on conducting-layer coated glass is a promising approach to lower the manufacturing cost of high-efficiency III-V tandem solar cells. We investigated the self-organizing formation of poly-Ge/Al/glass structures by using Al-<span class="hlt">induced</span> layer <span class="hlt">exchange</span>. The layer <span class="hlt">exchange</span> between amorphous Ge and Al layers was completed at a low temperature of 350°C. Forming the interlayer between Ge and Al, i.e., limiting the diffusion of Ge to Al lowered the Ge nucleation rate and then enlarged the grain size of the resulting poly-Ge layer. The natively oxidized Al interlayer, formed by exposing a thin Al membrane (2-nm thickness) to air for 180 min, led to the poly-Ge with grains 46 μm in size. Moreover, the Ge layer was highly (111)-oriented. This Ge/Al/glass structure appears promising for use in the bottom cell of the III-V semiconductor based tandem solar cells, as well as in the epitaxial templates for aligned nanowires and other advanced materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4529306','PMC'); return false;" href="http://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> </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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3766282','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3766282"><span id="translatedtitle">Modulation of radiation-<span class="hlt">induced</span> and mitomycin C-<span class="hlt">induced</span> chromosome damage by apigenin in human lymphocytes in vitro</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sharma, Narinder K.</p> <p>2013-01-01</p> <p>Apigenin (APG), a flavone, is known to exhibit antioxidant, antimutagenic and antitumorigenic activity, both in vivo and in vitro. The aim of this study is to investigate the modulatory effects of APG on human lymphocytes after irradiation with gamma rays (3 Gy) or treatment with the antineoplastic agent, mitomycin C (MMC), in vitro. Cytogenetic biomarkers such as chromosome aberrations (CAs), sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) and cytochalasin-B blocked micronuclei (CBMN), were studied in blood lymphocytes treated with radiation, or antineoplastic agent (MMC), and APG. Whole blood lymphocytes were cultured in vitro using a standard protocol. No significant differences were found in the frequency of CAs or micronuclei (MN) in human peripheral blood lymphocytes irradiated with gamma rays (3 Gy) and then post-treated with APG. There was an increase in the frequency of SCEs per cell in APG-treated samples compared with the controls. Lymphocytes treated with MMC in the presence of APG exhibited a significant decrease (P < 0.01) in the frequency of SCEs compared with MMC treatment alone. The data for the MN test indicated that APG treatment significantly reduced (P < 0.01) the frequency of MMC-<span class="hlt">induced</span> MN. PMID:23764456</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22402585','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22402585"><span id="translatedtitle">Comprehensive study of Al-<span class="hlt">induced</span> layer-<span class="hlt">exchange</span> growth for orientation-controlled Si crystals on SiO{sub 2} substrates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kurosawa, Masashi; Sadoh, Taizoh; Miyao, Masanobu</p> <p>2014-11-07</p> <p>Orientation-controlled crystalline Si films on insulating substrates are strongly required to achieve high-performance thin-film devices for next-generation electronics. We have comprehensively investigated the layer-<span class="hlt">exchange</span> kinetics of Al-<span class="hlt">induced</span> crystallization (AIC) in stacked structures, i.e., amorphous-Si/Al-oxide/Al/SiO{sub 2}-substrates, as a function of the air-exposure time of Al surfaces (t{sub air}: 0–24 h) to form Al-oxide interface-layers, the thickness of Al and Si layers (d{sub Al,} d{sub Si}: 50–200 nm), the annealing temperature (450–500 °C), and the annealing time (0–50 h). It has been clarified that longer t{sub air} (>60 min) and/or thinner d{sub Al} and d{sub Si} (<50 nm) lead to the (111) oriented growth; in contrast, shorter t{sub air} (<60 min) and/or thicker d{sub Al} and d{sub Si} (>100 nm) lead to the (100) oriented growth. No correlation between the annealing temperature and the crystal orientation is observed. Detailed analysis reveals that the layer-<span class="hlt">exchange</span> kinetics are dominated by “supply-limited” processing, i.e., diffusion of Si atoms into Al layers through Al-oxide layer. Based on the growth rate dependent Si concentration profiles in Al layers, and the free-energy of Si at Al-oxide/Al or Al/SiO{sub 2} interfaces, a comprehensive model for layer-<span class="hlt">exchange</span> growth is proposed. This well explains the experimental results of not only Si-AIC but also another material system such as gold-<span class="hlt">induced</span> crystallization of Ge. In this way, a growth technique achieving the orientation-controlled Si crystals on insulating substrates is established from both technological and scientific points of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115g5301I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115g5301I"><span id="translatedtitle">Effective Hamiltonians for Rapidly Driven Many-Body Lattice Systems: <span class="hlt">Induced</span> <span class="hlt">Exchange</span> Interactions and Density-Dependent Hoppings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Itin, A. P.; Katsnelson, M. I.</p> <p>2015-08-01</p> <p>We consider 1D lattices described by Hubbard or Bose-Hubbard models, in the presence of periodic high-frequency perturbations, such as uniform ac force or modulation of hopping coefficients. Effective Hamiltonians for interacting particles are derived using an averaging method resembling classical canonical perturbation theory. As is known, a high-frequency force may renormalize hopping coefficients, causing interesting phenomena such as coherent destruction of tunneling and creation of artificial gauge fields. We find explicitly additional corrections to the effective Hamiltonians due to interactions, corresponding to nontrivial processes such as single-particle density-dependent tunneling, correlated pair hoppings, nearest neighbor interactions, etc. Some of these processes arise also in multiband lattice models, and are capable of giving rise to a rich variety of quantum phases. The apparent contradiction with other methods, e.g., Floquet-Magnus expansion, is explained. The results may be useful for designing effective Hamiltonian models in experiments with ultracold atoms, as well as in the field of ultrafast nonequilibrium magnetism. An example of manipulating <span class="hlt">exchange</span> interaction in a Mott-Hubbard insulator is considered, where our corrections play an essential role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25643124','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25643124"><span id="translatedtitle">Placental Hypoxia Developed During Preeclampsia <span class="hlt">Induces</span> Telocytes Apoptosis in Chorionic Villi Affecting The Maternal-Fetus Metabolic <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bosco, Cleofina Becerra; Díaz, Eugenia Guerra; Gutierrez, Rodrigo Rojas; González, Jaime Montero; Parra-Cordero, Mauro; Rodrigo, Ramón Salinas; Barja, Pilar Yañez</p> <p>2016-01-01</p> <p>Telocytes (TC) are a new type of stromal cells initially found and studied in digestive and extra- digestive organs. These cells have a small cell body with 2 to 5 thin and extremely long cytoplasmic prolongations named telopodes. In recent years, TC have also been described in placental chorionic villi, located in a strategical position between the smooth muscle cells from fetal vessels and the myofibroblasts in the stromal villi. Unlike other organs, the placenta is not innervated and considering the strategic location of TC is has been postulated that TC function would be related to signal transduction mechanisms involved in the regulation of the fetal vessels blood flow, as well as in the shortening/lengthening of the chorionic villi, providing the necessary rhythmicity to the process of maternal/fetal metabolic <span class="hlt">exchange</span>. Preeclampsia (PE) is a systemic syndrome that affects 4%-6% of pregnancies worldwide. It is characterized by a placental state of ischemia-hypoxia which triggers an oxidative stress stage with the concomitant production of reactive oxygen species (ROS) leading to an increase in the degree of placental apoptosis. Placental vascular tone is regulated by the vasodilator nitric oxide (NO) and, in PE cases, NO is diverted towards the formation of peroxynitrite, a powerful oxidative agent whose activity leads to an increase of placental apoptosis degree that compromises TC and myofibroblasts, a key feature we would like to emphasize in this work. PMID:25643124</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19044625','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19044625"><span id="translatedtitle">Calculation of low-Z impurity pellet <span class="hlt">induced</span> fluxes of charge <span class="hlt">exchange</span> neutral particles escaping from magnetically confined toroidal plasmas.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goncharov, P R; Ozaki, T; Sudo, S; Tamura, N; Tolstikhina, I Yu; Sergeev, V Yu</p> <p>2008-10-01</p> <p>Measurements of energy- and time-resolved neutral hydrogen and helium fluxes from an impurity pellet ablation cloud, referred to as pellet charge <span class="hlt">exchange</span> or PCX experiments, can be used to study local fast ion energy distributions in fusion plasmas. The estimation of the local distribution function f(i)(E) of fast ions entering the cloud requires knowledge of both the fraction F(0)(E) of incident ions exiting the cloud as neutral atoms and the attenuation factor A(E,rho) describing the loss of fast atoms in the plasma. Determination of A(E,rho), in turn, requires the total stopping cross section sigma(loss) of neutral atoms in the plasma and the Jacobian reflecting the measurement geometry and the magnetic surface shape. The obtained functions F(0)(E) and A(E,rho) enter multiplicatively into the probability density for escaping neutral particle kinetic energy. A general calculation scheme has been developed and realized as a FORTRAN code, which is to be applied for the calculation of f(i)(E) from PCX experimental results obtained with low-Z impurity pellets. PMID:19044625</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4347488','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4347488"><span id="translatedtitle">Fluoxetine <span class="hlt">induces</span> alkalinization of astroglial cytosol through stimulation of sodium-hydrogen <span class="hlt">exchanger</span> 1: dissection of intracellular signaling pathways</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ren, Jienan; Song, Dan; Bai, Qiufang; Verkhratsky, Alexei; Peng, Liang</p> <p>2015-01-01</p> <p>Clinical evidence suggest astrocytic abnormality in major depression (MD) while treatment with anti-psychotic drugs affects astroglial functions. Astroglial cells are involved in pH homeostasis of the brain by transporting protons (through sodium-proton transporter 1, NHE1, glutamate transporters EAAT1/2 and proton-lactate co-transporter MCT1) and bicarbonate (through the sodium-bicarbonate co-transporter NBC or the chloride-bicarbonate <span class="hlt">exchanger</span> AE). Here we show that chronic treatment with fluoxetine increases astroglial pHi by stimulating NHE1-mediated proton extrusion. At a clinically relevant concentration of 1 μM, fluoxetine significantly increased astroglial pHi from 7.05 to 7.34 after 3 weeks and from 7.18 to 7.58 after 4 weeks of drug treatment. Stimulation of NHE1 is a result of transporter phosphorylation mediated by several intracellular signaling cascades that include MAPK/ERK1/2, PI3K/AKT and ribosomal S6 kinase (RSK). Fluoxetine stimulated phosphorylation of ERK1/2, AKT and RSK in a concentration dependent manner. Positive crosstalk exists between two signal pathways, MAPK/ERK1/2 and PI3K/AKT activated by fluoxetine since ERK1/2 phosphrylation could be abolished by inhibitors of PI3K, LY294002 and AKT, triciribine, and AKT phosphorylation by inhibitor of MAPK, U0126. As a result, RSK phosphorylation was not only inhibited by U0126 but also by inhibitor of LY294002. The NHE1 phoshorylation resulted in stimulation of NHE1 activity as revealed by the NH4Cl-prepulse technique; the increase of NHE1 activity was dependent on fluoxetine concentration, and could be inhibited by both U0126 and LY294002. Our findings suggest that regulation of astrocytic pHi and brain pH may be one of the mechanisms underlying fluoxetine action. PMID:25784857</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('http://www.ncbi.nlm.nih.gov/pubmed/19495847','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19495847"><span id="translatedtitle">Hypoxia-<span class="hlt">induced</span> cytosolic calcium decrease is mediated primarily by the forward mode of Na(+)/Ca(2+) <span class="hlt">exchanger</span> in smooth muscle cells of fetal ductus arteriosus.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hong, Haifa; Chen, Huiwen; Gao, Wei; Cai, Xiaoman; Sun, Yanjuan; Yin, Meng; Liu, Jinfen</p> <p>2009-10-01</p> <p>Closure of the ductus arteriosus (DA) after birth, essential for postnatal adaptation, is initiated by the transition from hypoxia to normoxia. The current study investigated how hypoxia affects the level of cytosolic calcium ([Ca(2+)](i)) in fetal lamb DA smooth muscle cells (DASMCs) and the role of calcium pumps in this process. The [Ca(2+)](i) variation in response to acute hypoxia was determined spectrofluorometrically with fura-3-AM in cultured fetal DASMCs. Interventions using chemicals or solutions including thapsigargin, vanadate, KB-R7943, alkaline PH9.0 solution, or Na(+)-free medium were administered when samples were exposed to acute hypoxia. The results show that [Ca(2+)](i) decreased dramatically under acute hypoxia. This decrease was not attenuated completely by an inhibitor of sarcoplasmic/endoplasmic reticulum Ca(2+) adenosine triphosphatase (ATPase) (SERCA), a blocker of plasma membrane Ca(2+) ATPase (PMCA), or an inhibitor and activator of the reserve mode of the Na(+)/Ca(2+) <span class="hlt">exchanger</span> (NCX). In contrast, KT-R9743, an inhibitor of the forward mode of NCX at a high concentration (30 microm), greatly diminished the hypoxia-<span class="hlt">induced</span> [Ca(2+)](i) decrease in fetal DASMCs. These results suggest that a hypoxia-<span class="hlt">induced</span> Ca(2+) decrease in fetal DASMCs results from cytosolic Ca(2+) efflux mediated primarily by the forward mode of NCX. PMID:19495847</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961294','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961294"><span id="translatedtitle">Biotic Control of Surface pH and Evidence of Light-<span class="hlt">Induced</span> H+ Pumping and Ca2+-H+ <span class="hlt">Exchange</span> in a Tropical Crustose Coralline Alga</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hofmann, Laurie C.; Koch, Marguerite; de Beer, Dirk</p> <p>2016-01-01</p> <p>Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA) using microsensors. We measured pH, oxygen (O2), and calcium (Ca2+) dynamics and fluxes at the thallus surface under ambient (8.1) and low (7.8) seawater pH (pHSW) and across a range of irradiances. Acetazolamide (AZ) was used to inhibit extracellular carbonic anhydrase (CAext), which mediates hydrolysis of HCO3-, and 4,4′ diisothiocyanatostilbene-2,2′-disulphonate (DIDS) that blocks direct HCO3- uptake by anion <span class="hlt">exchange</span> transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ <span class="hlt">exchange</span>. Rapid light-<span class="hlt">induced</span> H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-<span class="hlt">inducible</span> H+ pumps. Our results suggest that complex light-<span class="hlt">induced</span> ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA. PMID:27459463</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27459463','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27459463"><span id="translatedtitle">Biotic Control of Surface pH and Evidence of Light-<span class="hlt">Induced</span> H+ Pumping and Ca2+-H+ <span class="hlt">Exchange</span> in a Tropical Crustose Coralline Alga.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hofmann, Laurie C; Koch, Marguerite; de Beer, Dirk</p> <p>2016-01-01</p> <p>Presently, an incomplete mechanistic understanding of tropical reef macroalgae photosynthesis and calcification restricts predictions of how these important autotrophs will respond to global change. Therefore, we investigated the mechanistic link between inorganic carbon uptake pathways, photosynthesis and calcification in a tropical crustose coralline alga (CCA) using microsensors. We measured pH, oxygen (O2), and calcium (Ca2+) dynamics and fluxes at the thallus surface under ambient (8.1) and low (7.8) seawater pH (pHSW) and across a range of irradiances. Acetazolamide (AZ) was used to inhibit extracellular carbonic anhydrase (CAext), which mediates hydrolysis of HCO3-, and 4,4' diisothiocyanatostilbene-2,2'-disulphonate (DIDS) that blocks direct HCO3- uptake by anion <span class="hlt">exchange</span> transport. Both inhibited photosynthesis, suggesting both diffusive uptake of CO2 via HCO3- hydrolysis to CO2 and direct HCO3- ion transport are important in this CCA. Surface pH was raised approximately 0.3 units at saturating irradiance, but less when CAext was inhibited. Surface pH was lower at pHSW 7.8 than pHSW 8.1 in the dark, but not in the light. The Ca2+ fluxes were large, complex and temporally variable, but revealed net Ca2+ uptake under all conditions. The temporal variability in Ca2+ dynamics was potentially related to localized dissolution during epithallial cell sloughing, a strategy of CCA to remove epiphytes. Simultaneous Ca2+ and pH dynamics suggest the presence of Ca2+/H+ <span class="hlt">exchange</span>. Rapid light-<span class="hlt">induced</span> H+ surface dynamics that continued after inhibition of photosynthesis revealed the presence of a light-mediated, but photosynthesis-independent, proton pump. Thus, the study indicates metabolic control of surface pH can occur in CCA through photosynthesis and light-<span class="hlt">inducible</span> H+ pumps. Our results suggest that complex light-<span class="hlt">induced</span> ion pumps play an important role in biological processes related to inorganic carbon uptake and calcification in CCA. PMID:27459463</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3608299','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/23761013','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23761013"><span id="translatedtitle">Tempol prevents genotoxicity <span class="hlt">induced</span> by vorinostat: role of oxidative DNA damage.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alzoubi, Karem H; Khabour, Omar F; Jaber, Aya G; Al-Azzam, Sayer I; Mhaidat, Nizar M; Masadeh, Majed M</p> <p>2014-05-01</p> <p>Vorinostat is a member of histone deacetylase inhibitors, which represents a new class of anticancer agents for the treatment of solid and hematological malignancies. Studies have shown that these drugs <span class="hlt">induce</span> DNA damage in blood lymphocytes, which is proposed to be due to the generation of oxidative lesions. The increase in DNA damage is sometimes associated with risk of developing secondary cancer. Thus, finding a treatment that limits DNA damage caused by anticancer drugs would be beneficial. Tempol is a potent antioxidant that was shown to prevent DNA damage <span class="hlt">induced</span> by radiation. In this study, we aimed to investigate the harmful effects of vorinostat on DNA damage, and the possible protective effects of tempol against this damage. For that, the spontaneous frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs), chromosomal aberrations (CAs), and 8-hydroxy-2-deoxy guanosine (8-OHdG) levels were measured in cultured human lymphocytes treated with vorinostat and/or tempol. The results showed that vorinostat significantly increases the frequency of SCEs, CAs and 8-OHdG levels in human lymphocytes as compared to control. These increases were normalized by the treatment of cells with tempol. In conclusion, vorinostat is genotoxic to lymphocytes, and this toxicity is reduced by tempol. Such results could set the stage for future studies investigating the possible usefulness of antioxidants co-treatment in preventing the genotoxicity of vorinostat when used as anticancer in human. PMID:23761013</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4340380','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4340380"><span id="translatedtitle">Involvement of the Na+/Ca2+ <span class="hlt">exchanger</span> isoform 1 (NCX1) in Neuronal Growth Factor (NGF)-<span class="hlt">induced</span> Neuronal Differentiation through Ca2+-dependent Akt Phosphorylation*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Secondo, Agnese; Esposito, Alba; Sirabella, Rossana; Boscia, Francesca; Pannaccione, Anna; Molinaro, Pasquale; Cantile, Maria; Ciccone, Roselia; Sisalli, Maria Josè; Scorziello, Antonella; Di Renzo, Gianfranco; Annunziato, Lucio</p> <p>2015-01-01</p> <p>NGF <span class="hlt">induces</span> neuronal differentiation by modulating [Ca2+]i. However, the role of the three isoforms of the main Ca2+-extruding system, the Na+/Ca2+ <span class="hlt">exchanger</span> (NCX), in NGF-<span class="hlt">induced</span> differentiation remains unexplored. We investigated whether NCX1, NCX2, and NCX3 isoforms could play a relevant role in neuronal differentiation through the modulation of [Ca2+]i and the Akt pathway. NGF caused progressive neurite elongation; a significant increase of the well known marker of growth cones, GAP-43; and an enhancement of endoplasmic reticulum (ER) Ca2+ content and of Akt phosphorylation through an early activation of ERK1/2. Interestingly, during NGF-<span class="hlt">induced</span> differentiation, the NCX1 protein level increased, NCX3 decreased, and NCX2 remained unaffected. At the same time, NCX total activity increased. Moreover, NCX1 colocalized and coimmunoprecipitated with GAP-43, and NCX1 silencing prevented NGF-<span class="hlt">induced</span> effects on GAP-43 expression, Akt phosphorylation, and neurite outgrowth. On the other hand, the overexpression of its neuronal splicing isoform, NCX1.4, even in the absence of NGF, <span class="hlt">induced</span> an increase in Akt phosphorylation and GAP-43 protein expression. Interestingly, tetrodotoxin-sensitive Na+ currents and 1,3-benzenedicarboxylic acid, 4,4′-[1,4,10-trioxa-7,13-diazacyclopentadecane-7,13-diylbis(5-methoxy-6,12-benzofurandiyl)]bis-, tetrakis[(acetyloxy)methyl] ester-detected [Na+]i significantly increased in cells overexpressing NCX1.4 as well as ER Ca2+ content. This latter effect was prevented by tetrodotoxin. Furthermore, either the [Ca2+]i chelator(1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) (BAPTA-AM) or the PI3K inhibitor LY 294002 prevented Akt phosphorylation and GAP-43 protein expression rise in NCX1.4 overexpressing cells. Moreover, in primary cortical neurons, NCX1 silencing prevented Akt phosphorylation, GAP-43 and MAP2 overexpression, and neurite elongation. Collectively, these data show that NCX1 participates in neuronal differentiation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25858142','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25858142"><span id="translatedtitle">Light-<span class="hlt">induced</span> plasticity in leaf hydraulics, venation, anatomy, and gas <span class="hlt">exchange</span> in ecologically diverse Hawaiian lobeliads.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scoffoni, Christine; Kunkle, Justin; Pasquet-Kok, Jessica; Vuong, Christine; Patel, Amish J; Montgomery, Rebecca A; Givnish, Thomas J; Sack, Lawren</p> <p>2015-07-01</p> <p>Leaf hydraulic conductance (Kleaf ) quantifies the capacity of a leaf to transport liquid water and is a major constraint on light-saturated stomatal conductance (gs ) and photosynthetic rate (Amax ). Few studies have tested the plasticity of Kleaf and anatomy across growth light environments. These provided conflicting results. The Hawaiian lobeliads are an excellent system to examine plasticity, given the striking diversity in the light regimes they occupy, and their correspondingly wide range of Amax , allowing maximal carbon gain for success in given environments. We measured Kleaf , Amax , gs and leaf anatomical and structural traits, focusing on six species of lobeliads grown in a common garden under two irradiances (300/800 μmol photons m(-2)  s(-1) ). We tested hypotheses for light-<span class="hlt">induced</span> plasticity in each trait based on expectations from optimality. Kleaf , Amax , and gs differed strongly among species. Sun/shade plasticity was observed in Kleaf , Amax, and numerous traits relating to lamina and xylem anatomy, venation, and composition, but gs was not plastic with growth irradiance. Species native to higher irradiance showed greater hydraulic plasticity. Our results demonstrate that a wide set of leaf hydraulic, stomatal, photosynthetic, anatomical, and structural traits tend to shift together during plasticity and adaptation to diverse light regimes, optimizing performance from low to high irradiance. PMID:25858142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/6675430','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/6675430"><span id="translatedtitle">Ambient temperature effect on changes in heat <span class="hlt">exchange</span> and skin and coat thermoisolation <span class="hlt">induced</span> with nembutal in guinea pigs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Laszczyńska, J</p> <p>1983-01-01</p> <p>The experiment was carried out on adult male guinea pigs not adapted to cold at temperatures of 29 degrees, 20 degrees and 12 degrees C. During 150 minutes after nembutal injection the following values were recorded: oxygen consumption, subcutaneous, cutaneous and hair-coat temperatures. Using Hatfield's disc heat loss from the body surface by radiation and convection was measured. Nembutal not only inhibited thermogenetic processes at low ambient temperature, but decreased also heat production in a thermoneutral environment. This effect increased with decreasing ambient temperature. At the same time, there was a reduction in heat loss, although in a lower degree. The final result was a fall of the rectal temperature (even by 10 degrees C in a cold environment). Following nembutal administration skin thermoinsulation decreased slightly but the thermoinsulating activity of the hair-coat increased (the pilomotor response was more pronounced than in waking animals). Thermoregulation disturbances <span class="hlt">induced</span> by nembutal included mainly thermogenesis impairment. The effect of general anaesthesia on heat loss was without any greater importance for maintenance of thermic homeostasis of the organism. PMID:6675430</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=43251&keyword=pathologies&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=72032158&CFTOKEN=16676154','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=43251&keyword=pathologies&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=72032158&CFTOKEN=16676154"><span id="translatedtitle">SISTER-<span class="hlt">CHROMATID</span> <span class="hlt">EXCHANGE</span> INDUCTION IN RAT MATERNAL, EMBRYONIC AND EXTRA-EMBRYONIC CELLS AFTER IN VIVO EXPOSURE TO 4-NITROQUINOLINE 1-OXIDE</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>Genetic damage is associated with various embryo pathologies; and many teratogens and transplacental carcinogens are known to be genotoxic. The present study was aimed at charaterizing SCE induction levels in rodent maternal, embryonic and extra-embryonic cells after maternal exp...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4766842','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4766842"><span id="translatedtitle">HEAT <span class="hlt">EXCHANGER</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fox, T.H. III; Richey, T. Jr.; Winders, G.R.</p> <p>1962-10-23</p> <p>A heat <span class="hlt">exchanger</span> is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The <span class="hlt">exchanger</span> employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26211649','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26211649"><span id="translatedtitle">Role of Sodium-Hydrogen <span class="hlt">Exchanger</span>-1 (NHE-1) in the Effect of Exercise on Intermittent Hypoxia-<span class="hlt">Induced</span> Left Ventricular Dysfunction.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen M, Yu-Chih; Yang, Kun-Ta; Shen, Yan-Jhih; Cheng, Ching-Feng; Tu, Wei-Chia; Chen, Tsung-I</p> <p>2015-08-31</p> <p>Intermittent hypoxia (IH) occurs frequently in patients with obstructive sleep apnoea and can cause ventricular dysfunction. However, whether myocardial inflammation and sodium-hydrogen <span class="hlt">exchanger</span>-1 (NHE-1) expression play an important role in IH-<span class="hlt">induced</span> ventricular dysfunction remains unclear. This study aimed to investigate whether short-term exercise provides a protective effect on IH-<span class="hlt">induced</span> left ventricular (LV) function impairment. Male Sprague-Dawley rats were randomly assigned to 4 groups: control (CON), IH, exercise (EXE) or IH interspersed with EXE (IHEXE). IH rats were exposed to repetitive hypoxia/reoxygenation cycles (2%-6% O₂ for 2-5 s per 75 s, followed by 21% O₂ for 6 h/day) during the light phase for 12 consecutive days. EXE rats were habituated to treadmill running for 5 days, permitted 2 days of rest, and followed by 5 exercise bouts (30 m/min for 60 min on a 2% grade) on consecutive days during the dark phase. IHEXE rats were exposed to IH during the light phase interspersed with exercise programs during the dark phase on the same day. Cardiac function was quantified by echocardiographic evaluation. Myocardial levels of tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and NHE-1 were determined. IH rats showed LV dysfunction characterized by lower LV fractional shortening (LVFS%) and LV ejection fraction (LVEF%). LV dysfunction was associated with higher myocardial levels of TNF-α, IL-6 and NHE-1 mRNA and protein. These changes were not observed in IHEXE rats (P > 0.05 for all). EXE rats showed lower levels of NHE-1 protein than CON rats (P < 0.05). However, the levels of LVFS%, LVEF%, TNF-α and IL-6 protein and NHE-1 mRNA did not differ between EXE and CON rats (P > 0.05 for all). These data indicated that exercise may provide a protective effect on IH-<span class="hlt">induced</span> LV dysfunction by attenuating IH-<span class="hlt">induced</span> myocardial NHE-1 hyperactivity. PMID:26211649</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H11D1222H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H11D1222H"><span id="translatedtitle">Effect of Hyporheic <span class="hlt">Exchange</span> <span class="hlt">Induced</span> by Riverbed Dunes on Mixing of Contaminants Daylighting from Aquifers to Rivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hester, E. T.; Young, K. I.; Widdowson, M. A.</p> <p>2012-12-01</p> <p>Interaction of surface water and groundwater in hyporheic sediments of river systems is known to create unique biogeochemical conditions that can attenuate contaminants flowing downstream. In such cases, oxygen, carbon, and the contaminants themselves often advect together from sources in surface water. However, the ability of the hyporheic zone to attenuate contaminants in upwelling groundwater plumes as they exit to rivers is less known. Such reactions may be more dependent on mixing of carbon and oxygen sources from surface water with contaminants from deeper groundwater. A few studies have shown that attenuation in shallow sediments can be much greater than in upgradient aquifers, yet have not determined what site characteristics most control such "hyporheic natural attenuation." Here we focus on mixing between hyporheic flow paths <span class="hlt">induced</span> beneath riverbed dunes and flowpaths of adjacent upwelling of deeper groundwater. We simulated such mixing using numerical simulations of groundwater flow, particle tracking, and conservative tracer transport using MODFLOW, MODPATH, and MT3DMS, respectively. We conducted a sensitivity analysis that varied parameters which affect the degree of mixing. We found that mixing occurs only within a thin zone at the interface of hyporheic flow paths and upwelling groundwater flowpaths. We also found that variation of control parameters affects mixing zone size in two distinct ways. On the one hand, variation of sediment hydraulic conductivity (K), upwelling groundwater flowrate (bottom Q), and anisotropy all affect mixing zone size primarily by affecting the length of the mixing zone: mixing zone size increases as K increases, bottom Q decreases, or anisotropy decreases. On the other hand, sediment heterogeneity affects mixing zone size primarily by affecting the thickness of the mixing zone: mixing zone size increases as standard deviation of the K field increases and as the ratio of horizontal to vertical correlation scales of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19301149','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19301149"><span id="translatedtitle">The ambiguous role of the Na+-H+ <span class="hlt">exchanger</span> isoform 1 (NHE1) in leptin-<span class="hlt">induced</span> oxidative stress in human monocytes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Konstantinidis, Diamantis; Paletas, Konstantinos; Koliakos, George; Kaloyianni, Martha</p> <p>2009-11-01</p> <p>Leptin, a 16-kDa cytokine produced mainly by the adipose tissue, is known to increase energy expenditure while at the same time lowering food intake by acting directly on the hypothalamus. ObRb, the leptin receptor mostly involved in intracellular signaling, is expressed in a wide range of tissues, thus allowing leptin to affect a much broader diversity of biological processes. High concentrations of leptin are encountered in patients with hyperleptinemia, a condition which very often accompanies obesity and which is a direct result of leptin resistance. In the present study, moderate and high concentrations of leptin (16 and 160 ng/ml) were mostly utilized in order to investigate the role of this cytokine in oxidative stress levels in human monocytes. Leptin was found to increase oxidative species production as measured with 2',7'-dichlorodihydrofluorescein diacetate (general marker of oxidative species, but not O2-*) and dihydroethidium (marker of O2-*). Surprisingly, it also augmented superoxide dismutase activity. Inhibition of the Na+-H+ <span class="hlt">exchanger</span> isoform 1 (NHE1) also inhibited leptin-<span class="hlt">induced</span> superoxide anion production but at the same time amplified leptin-<span class="hlt">induced</span> production of other oxidative species. Signaling proteins such as phosphoinositide 3 kinase and conventional isoforms of protein kinase C (alpha-, beta(i)-, beta(ii)-), as well as NADPH oxidase, also participated in leptin signaling. Finally, leptin was found to increase glutathionylation levels of NHE1-bound heat shock protein 70 kDa (Hsp70) but not Hsp70 binding to NHE1. PMID:19301149</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4709268','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4709268"><span id="translatedtitle">The Rho-guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF governs susceptibility to diet-<span class="hlt">induced</span> obesity and type 2 diabetes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chang, Ying-Ju; Pownall, Scott; Jensen, Thomas E; Mouaaz, Samar; Foltz, Warren; Zhou, Lily; Liadis, Nicole; Woo, Minna; Hao, Zhenyue; Dutt, Previn; Bilan, Philip J; Klip, Amira; Mak, Tak; Stambolic, Vuk</p> <p>2015-01-01</p> <p>Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-<span class="hlt">induced</span> obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies. DOI: http://dx.doi.org/10.7554/eLife.06011.001 PMID:26512886</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26512886','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26512886"><span id="translatedtitle">The Rho-guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF governs susceptibility to diet-<span class="hlt">induced</span> obesity and type 2 diabetes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Ying-Ju; Pownall, Scott; Jensen, Thomas E; Mouaaz, Samar; Foltz, Warren; Zhou, Lily; Liadis, Nicole; Woo, Minna; Hao, Zhenyue; Dutt, Previn; Bilan, Philip J; Klip, Amira; Mak, Tak; Stambolic, Vuk</p> <p>2015-01-01</p> <p>Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide <span class="hlt">exchange</span> factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-<span class="hlt">induced</span> obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies. PMID:26512886</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10814853','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10814853"><span id="translatedtitle">The by-products generated during sarin synthesis in the Tokyo sarin disaster <span class="hlt">induced</span> inhibition of natural killer and cytotoxic T lymphocyte activity.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Q; Hirata, Y; Piao, S; Minami, M</p> <p>2000-05-01</p> <p>More than 5000 passengers on Tokyo subway trains were injured by the nerve gas, sarin and its by-products. Analysis of phosphor-carrying metabolites of sarin and its by-products in urine samples from the victims suggested that they were exposed not only to sarin, but also by-products generated during sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP) and diethyl methylphosphonate (DEMP). We suspected genetic after-effects due to sarin by-products, thus, we checked the frequency of sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) and found that SCE was significantly higher in the victims than in a control group, and that DIMP and DEMP significantly <span class="hlt">induced</span> human lymphocyte SCE in vitro. In the present study, to explore whether DIMP and DEMP, which <span class="hlt">induced</span> a high frequency of SCE of lymphocytes, also affected the lymphocyte functions, we examined the effect of DIMP and DEMP on splenic natural killer (NK) and splenic cytotoxic T lymphocyte (CTL) activity in mice, and NK activity of human lymphocytes in vitro. We found that DIMP and DEMP significantly inhibited NK and CTL activity in a dose-dependent manner. The inhibition <span class="hlt">induced</span> by DIMP was stronger than that by DEMP. The effect of DIMP and DEMP on the splenic NK activity of mice was stronger than on the splenic CTL activity, and the human lymphocytes is more sensitive to DIMP and DEMP than the splenocytes of mice. PMID:10814853</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=307542','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=307542"><span id="translatedtitle">The Chromokinesin, KLP3A, Drives Mitotic Spindle Pole Separation during Prometaphase and Anaphase and Facilitates <span class="hlt">Chromatid</span> Motility D⃞V⃞</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kwon, Mijung; Morales-Mulia, Sandra; Brust-Mascher, Ingrid; Rogers, Gregory C.; Sharp, David J.; Scholey, Jonathan M.</p> <p>2004-01-01</p> <p>Mitosis requires the concerted activities of multiple microtubule (MT)-based motor proteins. Here we examined the contribution of the chromokinesin, KLP3A, to mitotic spindle morphogenesis and chromosome movements in Drosophila embryos and cultured S2 cells. By immunofluorescence, KLP3A associates with nonfibrous punctae that concentrate in nuclei and display MT-dependent associations with spindles. These punctae concentrate in indistinct domains associated with chromosomes and central spindles and form distinct bands associated with telophase midbodies. The functional disruption of KLP3A by antibodies or dominant negative proteins in embryos, or by RNA interference (RNAi) in S2 cells, does not block mitosis but produces defects in mitotic spindles. Time-lapse confocal observations of mitosis in living embryos reveal that KLP3A inhibition disrupts the organization of interpolar (ip) MTs and produces short spindles. Kinetic analysis suggests that KLP3A contributes to spindle pole separation during the prometaphase-to-metaphase transition (when it antagonizes Ncd) and anaphase B, to normal rates of <span class="hlt">chromatid</span> motility during anaphase A, and to the proper spacing of daughter nuclei during telophase. We propose that KLP3A acts on MTs associated with chromosome arms and the central spindle to organize ipMT bundles, to drive spindle pole separation and to facilitate <span class="hlt">chromatid</span> motility. PMID:14528012</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22526492','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22526492"><span id="translatedtitle">In vitro studies on chemoprotective effect of borax against aflatoxin B1-<span class="hlt">induced</span> genetic damage in human lymphocytes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turkez, Hasan; Geyikoğlu, Fatime; Dirican, Ebubekir; Tatar, Abdulgani</p> <p>2012-12-01</p> <p>A common dietary contaminant, aflatoxin B1 (AFB1), has been shown to be a potent mutagen and carcinogen in humans and many animal species. Since the eradication of AFB1 contamination in agricultural products has been rare, the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Boron compounds like borax (BX) and boric acid are the major components of industry and their antioxidant role has recently been reported. In the present report, we evaluated the capability of BX to inhibit the rate of micronucleus (MN) and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) formations <span class="hlt">induced</span> by AFB1. There were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with AFB1 (3.12 ppm) as compared to controls. However, co-application of BX (1, 2 and 5 ppm) and AFB1 resulted in decreases of SCE and MN rates as compared to the group treated with AFB1 alone. Borax gave 30-50 % protection against AFB1 <span class="hlt">induced</span> SCEs and MNs. In conclusion, the support of borax was especially useful in aflatoxin-toxicated blood tissue. Thus, the risk on target tissues of AFB1 could be reduced and ensured early recovery from its toxicity. PMID:22526492</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5748472','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5748472"><span id="translatedtitle">Mechanisms of induction of SCE and mutations by BrdU and CldU and the use of inhibitors of DNA repair to study mechanisms of 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>Heartlein, M.W.</p> <p>1984-01-01</p> <p>The induction of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCE) and specific locus mutations was studied by utilizing incorporation into DNA of the nucleoside analogues 5-bromo-and 5-chlorodeoxyuridine (BrdU and CldU). CldU was found to <span class="hlt">induce</span> SCE seven-times more efficiently than BrdU at equal extracellular concentrations. This induction was linearly associated with substitution for thymidine from 0.5-20 ..mu..M. In these experiments, specific locus mutations were not detected at concentrations less than 50 ..mu..M and were not correlated with SCE induction. At concentrations greater than 50 ..mu..M, the mutagenicity of CldU and BrdU was similar, although BrdU was slightly more mutagenic than CldU. In the examination of radiation-<span class="hlt">induced</span> chromosome aberrations in mammalian lymphocytes, 3-aminobenzamide and cytosine arabinoside, which are excision repair inhibitors, were used to show that the induction of chromosome aberrations depends upon the ratio of base damage to directly-<span class="hlt">induced</span> DNA strand breaks for a particular radiation quality. In addition, it was shown that sensitivity of various mammalian species to X ray-<span class="hlt">induced</span> aberrations depends upon the rate of repair of base damage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3679082','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3679082"><span id="translatedtitle">GhCAX3 Gene, a Novel Ca2+/H+ <span class="hlt">Exchanger</span> from Cotton, Confers Regulation of Cold Response and ABA <span class="hlt">Induced</span> Signal Transduction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>He, Liangrong; Zhang, Wenwen; He, Xin; Zhang, Xianlong; Yang, Xiyan; Zhu, Longfu</p> <p>2013-01-01</p> <p>As a second messenger, Ca2+ plays a major role in cold <span class="hlt">induced</span> transduction via stimulus-specific increases in [Ca2+]cyt, which is called calcium signature. During this process, CAXs (Ca2+/H+ <span class="hlt">exchangers</span>) play critical role. For the first time, a putative Ca2+/H+ <span class="hlt">exchanger</span> GhCAX3 gene from upland cotton (Gossypium hirsutum cv. ‘YZ-1′) was isolated and characterized. It was highly expressed in all tissues of cotton except roots and fibers. This gene may act as a regulator in cotton’s response to abiotic stresses as it could be up-regulated by Ca2+, NaCl, ABA and cold stress. Similar to other CAXs, it was proved that GhCAX3 also had Ca2+ transport activity and the N-terminal regulatory region (NRR) through yeast complementation assay. Over-expression of GhCAX3 in tobacco showed less sensitivity to ABA during seed germination and seedling stages, and the phenotypic difference between wild type (WT) and transgenic plants was more significant when the NRR was truncated. Furthermore, GhCAX3 conferred cold tolerance in yeast as well as in tobacco seedlings based on physiological and molecular studies. However, transgenic plant seeds showed more sensitivity to cold stress compared to WT during seed germination, especially when expressed in N-terminal truncated version. Finally, the extent of sensitivity in transgenic lines was more severe than that in WT line under sodium tungstate treatment (an ABA repressor), indicating that ABA could alleviate cold sensitivity of GhCAX3 seeds, especially in short of its NRR. Meanwhile, we also found that overexpression of GhCAX3 could enhance some cold and ABA responsive marker genes. Taken together, these results suggested that GhCAX3 plays important roles in the cross-talk of ABA and cold signal transduction, and compared to full-length of GhCAX3, the absence of NRR could enhance the tolerance or sensitivity to cold stress, depending on seedling’s developmental stages. PMID:23776653</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983EOSTr..64..515R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983EOSTr..64..515R"><span id="translatedtitle">Science <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>Richman, Barbara T.</p> <p></p> <p>Dwindling scientific and technical <span class="hlt">exchange</span> between the United States and the Soviet Union and prospects for enhancing such <span class="hlt">exchanges</span> were discussed at an August 2 hearing by the Foreign Affairs Committee of the U.S. House of Representatives. The committee also heard overviews on the United States' approach to international <span class="hlt">exchange</span> of science and technology. The hearing was the first in a series on current and future international science and technology programs.Four of eight science and technology agreements with the USSR that have expired in the last 15 months, including one on space, have not been renewed. The remaining four agreements have been extended into 1987 and 1988. Two others, including one on oceanography, are scheduled to run out in 1984.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5276019','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5276019"><span id="translatedtitle">Heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Drury, C.R.</p> <p>1988-02-02</p> <p>A heat <span class="hlt">exchanger</span> having primary and secondary conduits in heat-<span class="hlt">exchanging</span> relationship is described comprising: at least one serpentine tube having parallel sections connected by reverse bends, the serpentine tube constituting one of the conduits; a group of open-ended tubes disposed adjacent to the parallel sections, the open-ended tubes constituting the other of the conduits, and forming a continuous mass of contacting tubes extending between and surrounding the serpentine tube sections; and means securing the mass of tubes together to form a predetermined cross-section of the entirety of the mass of open-ended tubes and tube sections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22416738','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22416738"><span id="translatedtitle">WRNIP1 functions upstream of DNA polymerase η in the UV-<span class="hlt">induced</span> DNA damage response</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yoshimura, Akari; Kobayashi, Yume; Tada, Shusuke; Seki, Masayuki; Enomoto, Takemi</p> <p>2014-09-12</p> <p>Highlights: • The UV sensitivity of POLH{sup −/−} cells was suppressed by disruption of WRNIP1. • In WRNIP1{sup −/−/−}/POLH{sup −/−} cells, mutation frequencies and SCE after irradiation reduced. • WRNIP1 defect recovered rate of fork progression after irradiation in POLH{sup −/−} cells. • WRNIP1 functions upstream of Polη in the translesion DNA synthesis pathway. - Abstract: WRNIP1 (WRN-interacting protein 1) was first identified as a factor that interacts with WRN, the protein that is defective in Werner syndrome (WS). WRNIP1 associates with DNA polymerase η (Polη), but the biological significance of this interaction remains unknown. In this study, we analyzed the functional interaction between WRNIP1 and Polη by generating knockouts of both genes in DT40 chicken cells. Disruption of WRNIP1 in Polη-disrupted (POLH{sup −/−}) cells suppressed the phenotypes associated with the loss of Polη: sensitivity to ultraviolet light (UV), delayed repair of cyclobutane pyrimidine dimers (CPD), elevated frequency of mutation, elevated levels of UV-<span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE), and reduced rate of fork progression after UV irradiation. These results suggest that WRNIP1 functions upstream of Polη in the response to UV irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872126','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872126"><span id="translatedtitle">Mechanistic insight into cadmium-<span class="hlt">induced</span> inactivation of the Bloom protein</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qin, Wei; Bazeille, Nicolas; Henry, Etienne; Zhang, Bo; Deprez, Eric; Xi, Xu-Guang</p> <p>2016-01-01</p> <p>Cadmium is a toxic metal that inactivates DNA-repair proteins via multiple mechanisms, including zinc substitution. In this study, we investigated the effect of Cd2+ on the Bloom protein (BLM), a DNA-repair helicase carrying a zinc-binding domain (ZBD) and playing a critical role to ensure genomic stability. One characteristics of BLM-deficient cells is the elevated rate of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, a phenomenon that is also <span class="hlt">induced</span> by Cd2+. Here, we show that Cd2+ strongly inhibits both ATPase and helicase activities of BLM. Cd2+ primarily prevents BLM-DNA interaction via its binding to sulfhydryl groups of solvent-exposed cysteine residues and, concomitantly, promotes the formation of large BLM multimers/aggregates. In contrast to previously described Cd2+ effects on other zinc-containing DNA-repair proteins, the ZBD appears to play a minor role in the Cd2+-mediated inhibition. While the Cd2+-dependent formation of inactive multimers and the defect of DNA-binding were fully reversible upon addition of EDTA, the inhibition of the DNA unwinding activity was not counteracted by EDTA, indicating another mechanism of inhibition by Cd2+ relative to the targeting of a catalytic residue. Altogether, our results provide new clues for understanding the mechanism behind the ZBD-independent inactivation of BLM by Cd2+ leading to accumulation of DNA double-strand breaks. PMID:27194376</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9804941','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9804941"><span id="translatedtitle">In vivo and in vitro antigenotoxic effect of nordihydroguaiaretic acid against SCEs <span class="hlt">induced</span> by methyl methanesulfonate.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Madrigal-Bujaidar, E; Díaz Barriga, S; Cassani, M; Márquez, P; Revuelta, P</p> <p>1998-11-01</p> <p>Nordihydroguaiaretic acid (NDGA) is a phenolic lignan which has shown to cause a variety of actions potentially useful for human health; therefore, in this investigation we determined its capacity for inhibiting the rate of sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs) <span class="hlt">induced</span> by methyl methanesulfonate (MMS). We tested the effect of 0.25, 0.50, 1.0, and 2.0 microM of NDGA on the damage exerted by 55 microM of MMS. Cultured human lymphocytes from two female donors were used for the experiment. The best result concerning its modulatory action was obtained with 1.0 microM of NDGA; with this dose the mean inhibitory index including both donors reached 68.2%. The values obtained for the mitotic and proliferative indexes were not significantly modified with respect to the basal data. We also used the mouse bone marrow in vivo system to evaluate the inhibitory effect of the chemical. In this study we tested 1.0, 6.0, and 11.0 mg/kg of NDGA intraperitoneally (i.p.) administered 1 h before an i.p. injection of MMS (40 mg/kg). The best inhibitory index in this model corresponded to the dose of 11 mg/kg of NDGA (86.9%). The mitotic index and the average generation time showed no significant variation with respect to the control data. Our study established that NDGA produces antigenotoxic action in mammalian cells in vitro and in vivo. PMID:9804941</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863465','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863465"><span id="translatedtitle">Heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Daman, Ernest L.; McCallister, Robert A.</p> <p>1979-01-01</p> <p>A heat <span class="hlt">exchanger</span> is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70032533','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70032533"><span id="translatedtitle">Influence of a thin veneer of low-hydraulic-conductivity sediment on modelled <span class="hlt">exchange</span> between river water and groundwater in response to <span class="hlt">induced</span> infiltration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rosenberry, D.O.; Healy, R.W.</p> <p>2012-01-01</p> <p>A thin layer of fine-grained sediment commonly is deposited at the sediment-water interface of streams and rivers during low-flow conditions, and may hinder <span class="hlt">exchange</span> at the sediment-water interface similar to that observed at many riverbank-filtration (RBF) sites. Results from a numerical groundwater-flow model indicate that a low-permeability veneer reduces the contribution of river water to a pumping well in a riparian aquifer to various degrees, depending on simulated hydraulic gradients, hydrogeological properties, and pumping conditions. Seepage of river water is reduced by 5-10% when a 2-cm thick, low-permeability veneer is present on the bed surface. Increasing thickness of the low-permeability layer to 0??1 m has little effect on distribution of seepage or percentage contribution from the river to the pumping well. A three-orders-of-magnitude reduction in hydraulic conductivity of the veneer is required to reduce seepage from the river to the extent typically associated with clogging at RBF sites. This degree of reduction is much larger than field-measured values that were on the order of a factor of 20-25. Over 90% of seepage occurs within 12 m of the shoreline closest to the pumping well for most simulations. Virtually no seepage occurs through the thalweg near the shoreline opposite the pumping well, although no low-permeability sediment was simulated for the thalweg. These results are relevant to natural settings that favour formation of a substantial, low-permeability sediment veneer, as well as central-pivot irrigation systems, and municipal water supplies where river seepage is <span class="hlt">induced</span> via pumping wells. Published in 2011 by John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2697716','PMC'); return false;" href="http://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('http://adsabs.harvard.edu/abs/2016JMagR.265...45B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMagR.265...45B"><span id="translatedtitle">Nonadiabatic <span class="hlt">exchange</span> dynamics during adiabatic frequency sweeps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbara, Thomas M.</p> <p>2016-04-01</p> <p>A Bloch equation analysis that includes relaxation and <span class="hlt">exchange</span> effects during an adiabatic frequency swept pulse is presented. For a large class of sweeps, relaxation can be incorporated using simple first order perturbation theory. For anisochronous <span class="hlt">exchange</span>, new expressions are derived for <span class="hlt">exchange</span> augmented rotating frame relaxation. For isochronous <span class="hlt">exchange</span> between sites with distinct relaxation rate constants outside the extreme narrowing limit, simple criteria for adiabatic <span class="hlt">exchange</span> are derived and demonstrate that frequency sweeps commonly in use may not be adiabatic with regard to <span class="hlt">exchange</span> unless the <span class="hlt">exchange</span> rates are much larger than the relaxation rates. Otherwise, accurate assessment of the sensitivity to <span class="hlt">exchange</span> dynamics will require numerical integration of the rate equations. Examples of this situation are given for experimentally relevant parameters believed to hold for in-vivo tissue. These results are of significance in the study of <span class="hlt">exchange</span> <span class="hlt">induced</span> contrast in magnetic resonance imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4673635','PMC'); return false;" href="http://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('http://www.ncbi.nlm.nih.gov/pubmed/24549317','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24549317"><span id="translatedtitle">Downregulation of Rap1 promotes 5-fluorouracil-<span class="hlt">induced</span> apoptosis in hepatocellular carcinoma cell line HepG2.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zha, Yong; Gan, Ping; Yao, Qian; Ran, Feng-Ming; Tan, Jing</p> <p>2014-04-01</p> <p>Recent studies have revealed that repressor/activator protein (Rap1) not only protects telomeres from sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span>, but also functions in genomewide transcriptional regulation. Knockdown of Rap1 sensitizes breast cancer cells to adriamycin-<span class="hlt">induced</span> apoptosis. However, little is known about the role of Rap1 in the progression of hepatocellular carcinoma (HCC). The present study aimed to investigate the functions of Rap1 in HCC progression and to determine whether targeting the Rap1 signaling pathway may be of therapeutic value against HCC. We found knockdown of Rap1 by microRNA (miRNA) interference enhanced significantly apoptosis and 5-fluorouracil (5-FU) chemosensitivity in HepG2 cell line. Rap1 miRNA downregulated nuclear factor-κB p65 (NF-κB p65) expression, and upregulated inhibitor of NF-κB (IκB) expression. In vivo, Rap1 miRNA combined with 5-FU treatment led to a significant reduction of tumor growth as compared with 5-FU alone. The results indicate that Rap1 miRNA can effectively enhance sensitivity of HepG2 cell line to 5-FU chemotherapy in vitro and in vivo. PMID:24549317</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('http://www.ncbi.nlm.nih.gov/pubmed/2228998','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2228998"><span id="translatedtitle">Plasma <span class="hlt">exchange</span> in endocrine ophthalmopathy.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berlin, G; Hjelm, H; Liedén, G; Tegler, L</p> <p>1990-01-01</p> <p>We studied the effects of intensive plasma <span class="hlt">exchange</span> on endocrine ophthalmopathy in 12 patients with Graves' disease and one with Hashimoto's thyroiditis. All patients were euthyroid at the time of plasma <span class="hlt">exchange</span>. All but five had concomitant treatment with azathioprine. Each patient had a treatment period consisting of six plasma <span class="hlt">exchanges</span> performed in 2-3 weeks; two patients were treated in two periods. Each time a mean of 2.4 liters plasma was <span class="hlt">exchanged</span>. There was a prompt reduction in the concentration of circulating immune complexes and/or thyrotropin receptor antibodies following plasma <span class="hlt">exchange</span>. Six of the 13 patients improved their proptosis; their median duration of eye symptoms before treatment was less than 8 months. In patients suffering from eye symptoms for more than 1 year improvement was rare. Overall the Hertel values were 24.1 +/- 4.4 (SD) before and 22.8 +/- 3.4 after plasma <span class="hlt">exchange</span> for the left eyes (P = 0.07) and 23.8 +/- 4.0 before and 23.0 +/- 3.8 after for the right eyes (P = 0.09). Nine patients altogether improved their ophthalmopathy index and periorbital oedema. In patients with disabling endocrine ophthalmopathy plasma <span class="hlt">exchange</span> may sometimes be of value to <span class="hlt">induce</span> a relief of the ophthalmopathy; when it is used it should be instituted before fibrotic changes occur. We suggest that concomitant immunosuppressive drugs should be given to prevent rebound phenomenon <span class="hlt">induced</span> by plasma <span class="hlt">exchange</span>. To establish the role of plasma <span class="hlt">exchange</span> in the treatment of endocrine ophthalmopathy controlled studies should be performed. PMID:2228998</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/biblio/6515249','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6515249"><span id="translatedtitle">Repair of chromosome damage <span class="hlt">induced</span> by X-irradiation during G/sub 2/ phase in a line of normal human fibroblasts and its malignant derivative</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parshad, R.; Gantt, R.; Sanford, K.K.; Jones, G.M.; Tarone, R.E.</p> <p>1982-08-01</p> <p>A line of normal human skin fibroblasts (KD) differed from its malignant derivative (HUT-14) in the extent of cytogenetic damage <span class="hlt">induced</span> by X-irradiation during G/sub 2/ phase. Malignant cells had significantly more <span class="hlt">chromatid</span> breaks and gaps after exposure to 25, 50, or 100 rad. Results from alkaline elution of cellular DNA immediately after irradiation showed that the normal and malignant cells in asynchronous population were equally sensitive to DNA single-strand breakage by X-irradiation. Caffeine or ..beta..-cytosine arabinoside (ara-C), inhibitors of DNA repair, when added directly following G/sub 2/ phase exposure, significantly increased the incidence of radiation-<span class="hlt">induced</span> <span class="hlt">chromatid</span> damage in the normal cells. In contrast, similar treatment of the malignant cells had little influence. Ara-C differed from caffeine in its effects; whereas both agents increased the frequency of <span class="hlt">chromatid</span> breaks and gaps, only ara-C increased the frequency of gaps to the level observed in the irradiated malignant cells. Addition of catalase, which destroys H/sub 2/O/sub 2/, or mannitol, a scavenger of the derivative free hydroxyl radical (.OH), to the cultures of malignant cells before, during, and following irradiation significantly reduced the <span class="hlt">chromatid</span> damage; and catalase prevented formation of <span class="hlt">chromatid</span> gaps. The DNA damage <span class="hlt">induced</span> by X-ray during G/sub 2/ phase in the normal KD cells was apparently repaired by a caffeine- and ara-C-sensitive mechanism(s) that was deficient or absent in their malignant derivatives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25645230','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25645230"><span id="translatedtitle">Ameliorative effect of certain antioxidants against mercury <span class="hlt">induced</span> genotoxicity in peripheral blood lymphocytes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patel, Tapan A; Rao, Mandava V</p> <p>2015-10-01</p> <p>Various antioxidants play an important role in reducing the reactive oxygen species (ROS) by scavenging them directly or indirectly. Mercury (Hg) is one of the known hazardous genotoxicant, <span class="hlt">induces</span> the genotoxicity by enhancing the ROS. In the present study, three structurally different bioactive compounds such as melatonin (0.2 mM), curcumin (3.87 µM) and andrographolide (0.4 µM) were evaluated against the genotoxic effect of mercury. All the experiments were conducted using the peripheral blood lymphocytes In Vitro. The cultures were exposed to different doses (2.63 µM; 6.57 µM; 10.52 µM) of mercury salt (HgCl2) for studying various genotoxic indices. All three antioxidant compounds, alone and in combination with high dose of mercury, were added to the cultures with controls. For ascertaining genotoxicity, sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> (SCEs), cell cycle proliferative index/replicative index (CCPI/RI), average generation time (AGT), population doubling time (PDT), %M1, %M2 and %M3 were assessed and analyzed using suitable statistical analysis. The results revealed a dose dependent increase in SCEs, AGT and PDT, with a concomitant reduction in CCPI values after treatment of mercury. Supplementation of these three antioxidant compounds effectively negated these genotoxic endpoints in treated cultures with improvement in the cell cycle kinetics i.e. CCPI. The antimutagenic activity of these compounds on mercury <span class="hlt">induced</span> genotoxicity was in the following order: melatonin > curcumin > andrographolide. In conclusion, these compounds have ameliorated mercury <span class="hlt">induced</span> increase in genotoxic indices due to their excellent antioxidant properties and the combination seems to be effective. PMID:25645230</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1011401','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1011401"><span id="translatedtitle">Segmented heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann</p> <p>2010-12-14</p> <p>A segmented heat <span class="hlt">exchanger</span> system for transferring heat energy from an exhaust fluid to a working fluid. The heat <span class="hlt">exchanger</span> system may include a first heat <span class="hlt">exchanger</span> for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat <span class="hlt">exchanger</span> in a parallel flow configuration. In addition, the heat <span class="hlt">exchanger</span> system may include a second heat <span class="hlt">exchanger</span> for receiving working fluid from the first heat <span class="hlt">exchanger</span> and exhaust fluid from a third heat <span class="hlt">exchanger</span>. The working fluid and exhaust fluid may travel through at least a portion of the second heat <span class="hlt">exchanger</span> in a counter flow configuration. Furthermore, the heat <span class="hlt">exchanger</span> system may include a third heat <span class="hlt">exchanger</span> for receiving working fluid from the second heat <span class="hlt">exchanger</span> and exhaust fluid from the first heat <span class="hlt">exchanger</span>. The working fluid and exhaust fluid may travel through at least a portion of the third heat <span class="hlt">exchanger</span> in a parallel flow configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2895640','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2895640"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Covo, Shay; Westmoreland, James W.</p> <p>2010-01-01</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 G2/M cells. The decreased survival reflected a reduction in DSB repair. Importantly, HR between homologous chromosomes was strongly increased by ionizing radiation in G2/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 G2/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. PMID:20617204</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012cosp...39...47A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012cosp...39...47A&link_type=ABSTRACT"><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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082875','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082875"><span id="translatedtitle">Xanthium strumarium L. Extracts Produce DNA Damage Mediated by Cytotoxicity in In Vitro Assays but Does Not <span class="hlt">Induce</span> Micronucleus in Mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Piloto Ferrer, Janet; Cozzi, Renata; Cornetta, Tommaso; Stano, Pasquale; Fiore, Mario; Degrassi, Francesca; De Salvia, Rosella; Remigio, Antonia; Francisco, Marbelis; Quiñones, Olga; Valdivia, Dayana; González, Maria L.; Pérez, Carlos; Sánchez-Lamar, Angel</p> <p>2014-01-01</p> <p>Xanthium strumarium L. is a member of the Asteraceae commonly used in Cuba, mainly as diuretic. Some toxic properties of this plant have also been reported and, to date, very little is known about its genotoxic properties. The present work aims was to evaluate the potential cytotoxic and genotoxic risk of whole extract from Xanthium strumarium L. whole extract of aerial parts. No positive response was observed in a battery of four Salmonella typhimurium strains, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation (liver microsomal S9 fraction from Wistar rats). In CHO cells, high concentrations (25–100 μg/mL) revealed significant reduction in cell viability. Results from sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosome aberrations, and comet assay showed that X. strumarium extract is genotoxic at the highest concentration used, when clear cytotoxic effects were also observed. On the contrary, no increase in micronuclei frequency in bone marrow cells was observed when the extract was orally administered to mice (100, 500, and 2000 mg/Kg doses). The data presented here constitute the most complete study on the genotoxic potential of X. strumarium L. and show that the extract can <span class="hlt">induce</span> in vitro DNA damage at cytotoxic concentrations. PMID:25025061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25025061','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25025061"><span id="translatedtitle">Xanthium strumarium L. extracts produce DNA damage mediated by cytotoxicity in in vitro assays but does not <span class="hlt">induce</span> micronucleus in mice.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Piloto Ferrer, Janet; Cozzi, Renata; Cornetta, Tommaso; Stano, Pasquale; Fiore, Mario; Degrassi, Francesca; De Salvia, Rosella; Remigio, Antonia; Francisco, Marbelis; Quiñones, Olga; Valdivia, Dayana; González, Maria L; Pérez, Carlos; Sánchez-Lamar, Angel</p> <p>2014-01-01</p> <p>Xanthium strumarium L. is a member of the Asteraceae commonly used in Cuba, mainly as diuretic. Some toxic properties of this plant have also been reported and, to date, very little is known about its genotoxic properties. The present work aims was to evaluate the potential cytotoxic and genotoxic risk of whole extract from Xanthium strumarium L. whole extract of aerial parts. No positive response was observed in a battery of four Salmonella typhimurium strains, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation (liver microsomal S9 fraction from Wistar rats). In CHO cells, high concentrations (25-100 μg/mL) revealed significant reduction in cell viability. Results from sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>, chromosome aberrations, and comet assay showed that X. strumarium extract is genotoxic at the highest concentration used, when clear cytotoxic effects were also observed. On the contrary, no increase in micronuclei frequency in bone marrow cells was observed when the extract was orally administered to mice (100, 500, and 2000 mg/Kg doses). The data presented here constitute the most complete study on the genotoxic potential of X. strumarium L. and show that the extract can <span class="hlt">induce</span> in vitro DNA damage at cytotoxic concentrations. PMID:25025061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED428920.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED428920.pdf"><span id="translatedtitle">Educator <span class="hlt">Exchange</span> Resource Guide.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Garza, Cris; Rodriguez, Victor</p> <p></p> <p>This resource guide was developed for teachers and administrators interested in participating in intercultural and international <span class="hlt">exchange</span> programs or starting an <span class="hlt">exchange</span> program. An analysis of an <span class="hlt">exchange</span> program's critical elements discusses <span class="hlt">exchange</span> activities; orientation sessions; duration of <span class="hlt">exchange</span>; criteria for participation; travel,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22681112','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22681112"><span id="translatedtitle">Giant ferroelectric polarization of CaMn7O12 <span class="hlt">induced</span> by a combined effect of Dzyaloshinskii-Moriya interaction and <span class="hlt">exchange</span> striction.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, X Z; Whangbo, M-H; Dong, Shuai; Gong, X G; Xiang, H J</p> <p>2012-05-01</p> <p>By extending our general spin-current model to noncentrosymmetric spin dimers and performing density functional calculations, we investigate the causes for the helical magnetic order and the origin of the giant ferroelectric polarization of CaMn7O12. The giant ferroelectric polarization is proposed to be caused by the symmetric <span class="hlt">exchange</span> striction due to the canting of the Mn4+ spin arising from its strong Dzyaloshinskii-Moriya interaction. Our study suggests that CaMn7O12 may exhibit a novel magnetoelectric coupling mechanism in which the magnitude of the polarization is governed by the <span class="hlt">exchange</span> striction, but the direction of the polarization by the chirality of the helical magnetic order. PMID:22681112</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1210146','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1210146"><span id="translatedtitle"><span class="hlt">Exchange</span> bias effect in Au-Fe<sub>3</sub>O<sub>4</sub> dumbbell nanoparticles <span class="hlt">induced</span> by the charge transfer from gold</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; Dai, Sheng</p> <p>2015-08-10</p> <p>We have studied the origin of the <span class="hlt">exchange</span> bias effect in the Au-Fe<sub>3</sub>O<sub>4</sub> dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe<sub>3</sub>O<sub>4</sub> nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe<sub>3</sub>O<sub>4</sub> nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe<sub>3</sub>O<sub>4</sub> is giving rise to the <span class="hlt">exchange</span> bias effect. The strength of the <span class="hlt">exchange</span> bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe<sub>3</sub>O<sub>4</sub> into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26423135','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26423135"><span id="translatedtitle">The lethal response to Cdk1 inhibition depends on sister <span class="hlt">chromatid</span> alignment errors generated by KIF4 and isoform 1 of PRC1.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Voets, Erik; Marsman, Judith; Demmers, Jeroen; Beijersbergen, Roderick; Wolthuis, Rob</p> <p>2015-01-01</p> <p>Cyclin-dependent kinase 1 (Cdk1) is absolutely essential for cell division. Complete ablation of Cdk1 precludes the entry of G2 phase cells into mitosis, and is early embryonic lethal in mice. Dampening Cdk1 activation, by reducing gene expression or upon treatment with cell-permeable Cdk1 inhibitors, is also detrimental for proliferating cells, but has been associated with defects in mitotic progression, and the formation of aneuploid daughter cells. Here, we used a large-scale RNAi screen to identify the human genes that critically determine the cellular toxicity of Cdk1 inhibition. We show that Cdk1 inhibition leads to fatal sister <span class="hlt">chromatid</span> alignment errors and mitotic arrest in the spindle checkpoint. These problems start early in mitosis and are alleviated by depletion of isoform 1 of PRC1 (PRC1-1), by gene ablation of its binding partner KIF4, or by abrogation of KIF4 motor activity. Our results show that, normally, Cdk1 activity must rise above the level required for mitotic entry. This prevents KIF4-dependent PRC1-1 translocation to astral microtubule tips and safeguards proper chromosome congression. We conclude that cell death in response to Cdk1 inhibitors directly relates to chromosome alignment defects generated by insufficient repression of PRC1-1 and KIF4 during prometaphase. PMID:26423135</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17977840','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17977840"><span id="translatedtitle">Hst3 is regulated by Mec1-dependent proteolysis and controls the S phase checkpoint and sister <span class="hlt">chromatid</span> cohesion by deacetylating histone H3 at lysine 56.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thaminy, Safia; Newcomb, Benjamin; Kim, Jessica; Gatbonton, Tonibelle; Foss, Eric; Simon, Julian; Bedalov, Antonio</p> <p>2007-12-28</p> <p>The SIR2 homologues HST3 and HST4 have been implicated in maintenance of genome integrity in the yeast Saccharomyces cerevisiae. We find that Hst3 has NAD-dependent histone deacetylase activity in vitro and that it functions during S phase to deacetylate the core domain of histone H3 at lysine 56 (H3K56). In response to genotoxic stress, Hst3 undergoes rapid Mec1-dependent phosphorylation and is targeted for ubiquitin-mediated proteolysis, thus providing a mechanism for the previously observed checkpoint-dependent accumulation of Ac-H3K56 at sites of DNA damage. Loss of Hst3-mediated regulation of H3K56 acetylation results in a defect in the S phase DNA damage checkpoint. The pathway that regulates H3K56 acetylation acts in parallel with the Rad9 pathway to transmit a DNA damage signal from Mec1 to Rad53. We also observe that loss of Hst3 function impairs sister <span class="hlt">chromatid</span> cohesion (SCC). Both S phase checkpoint and SCC defects are phenocopied by H3K56 point mutants. Our findings demonstrate that Hst3-regulated H3K56 acetylation safeguards genome stability by controlling the S phase DNA damage response and promoting SCC. PMID:17977840</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2064017','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2064017"><span id="translatedtitle">RAD51C deficiency in mice results in early prophase I arrest in males and sister <span class="hlt">chromatid</span> separation at metaphase II in females</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kuznetsov, Sergey; Pellegrini, Manuela; Shuda, Kristy; Fernandez-Capetillo, Oscar; Liu, Yilun; Martin, Betty K.; Burkett, Sandra; Southon, Eileen; Pati, Debananda; Tessarollo, Lino; West, Stephen C.; Donovan, Peter J.; Nussenzweig, Andre; Sharan, Shyam K.</p> <p>2007-01-01</p> <p>RAD51C is a member of the RecA/RAD51 protein family, which is known to play an important role in DNA repair by homologous recombination. In mice, it is essential for viability. Therefore, we have generated a hypomorphic allele of Rad51c in addition to a null allele. A subset of mice expressing the hypomorphic allele is infertile. This infertility is caused by sexually dimorphic defects in meiotic recombination, revealing its two distinct functions. Spermatocytes undergo a developmental arrest during the early stages of meiotic prophase I, providing evidence for the role of RAD51C in early stages of RAD51-mediated recombination. In contrast, oocytes can progress normally to metaphase I after superovulation but display precocious separation of sister <span class="hlt">chromatids</span>, aneuploidy, and broken chromosomes at metaphase II. These defects suggest a possible late role of RAD51C in meiotic recombination. Based on the marked reduction in Holliday junction (HJ) resolution activity in Rad51c-null mouse embryonic fibroblasts, we propose that this late function may be associated with HJ resolution. PMID:17312021</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=365491','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=365491"><span id="translatedtitle"><span class="hlt">Inducible</span> expression and cytogenetic effects of the EcoRI restriction endonuclease in Chinese hamster ovary 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>Morgan, W F; Fero, M L; Land, M C; Winegar, R A</p> <p>1988-01-01</p> <p>The cytogenetic endpoints sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) and chromosome aberrations are widely used as indicators of DNA damage <span class="hlt">induced</span> by mutagenic carcinogens. Chromosome aberrations appear to result directly from DNA double-strand breaks, but the lesion(s) giving rise to SCE formation remains unknown. Most compounds that <span class="hlt">induce</span> SCEs <span class="hlt">induce</span> a spectrum of lesions in DNA. To investigate the role of double-strand breakage in SCE formation, we constructed a plasmid that gives rise to one specific lesion, a staggered-end ("cohesive") DNA double-strand break. This plasmid, designated pMENs, contains a selectable marker, neo, which is a bacterial gene for neomycin resistance, and the coding sequence for the bacterial restriction endonuclease EcoRI attached to the mouse metallothionein gene promoter. EcoRI recognizes G decreases AATTC sequences in DNA and makes DNA double-strand breaks with four nucleotides overhanging as staggered ends. Cells transfected with pMENS were resistant to the antibiotic G418 and contained an integrated copy of the EcoRI gene, detectable by DNA filter hybridization. The addition of the heavy metal CdSO4 resulted in the intracellular production of EcoRI, as measured by an anti-EcoRI antibody. Cytogenetic analysis after the addition of CdSO4 indicated a dramatic increase in the frequency of chromosome aberrations but very little effect on SCE frequency. Although there was some intercellular heterogeneity, these results confirm that DNA double-strand breaks do result in chromosome aberrations but that these breaks are not sufficient to give rise to SCE formation. Images PMID:3054512</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999731"><span id="translatedtitle">Oxygen desaturation during a 6-minute walk test as a predictor of maximal exercise-<span class="hlt">induced</span> gas <span class="hlt">exchange</span> abnormalities in sarcoidosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chenivesse, Cecile; Boulanger, Sarah; Langlois, Carole; Wemeau-Stervinou, Lidwine; Perez, Thierry</p> <p>2016-01-01</p> <p>Background Common tests for evaluating gas <span class="hlt">exchange</span> impairment have different strengths and weaknesses. Alveolar-to-arterial oxygen pressure difference (AaDO2) at peak exercise is a sensitive indicator but it cannot be measured repeatedly. Diffusing capacity of the lung for carbon monoxide (DLco) is measured at rest and may be too insensitive to predict the effects of exercise on gas <span class="hlt">exchange</span> impairment. Oxygen desaturation during a 6-minute walk test (∆SpO2-6MWT) can be measured repeatedly, but its value in sarcoidosis is unknown. Here, we evaluated the ability of ∆SpO2-6MWT and DLco to predict gas <span class="hlt">exchange</span> impairment during exercise in sarcoidosis. Methods This retrospective study of 130 subjects with sarcoidosis investigated the relationship between DLco, ∆SpO2-6MWT, and peak AaDO2 using correlation tests, inter-test reliability analyses, and predictive values. For the analyses of inter-test reliability and predictive values, DLco, peak AaDO2, and ∆SpO2-6MWT were considered as binary variables (normal/abnormal) according to previously defined thresholds. Results Correlation coefficients between DLco, ∆SpO2-6MWT, and peak AaDO2 were intermediate (0.53–0.67, P<0.0003) and Kappa coefficients were low (0.21–0.42, P=0.0003–0.02). DLco predicted (I) increased peak AaDO2 with a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 78% and (II) increased ∆SpO2-6MWT with a PPV at 36% and an NPV at 88%. Normal DLco was a good predictor of the absence of severe desaturation during the 6MWT (94% NPV) and at peak exercise during cardiopulmonary exercise test (CPET) (100% NPV). ∆SpO2-6MWT predicted peak AaDO2 increase with a PPV of 74% and an NPV of 60%. Conclusions In a large population of sarcoidosis patients, neither ∆SpO2-6MWT nor DLco was a good predictor of increased peak AaDO2. In contrast, normal DLco was a good predictor of the absence of severe desaturation during the 6MWT and at peak exercise during CPET. PMID</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('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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4302738','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4302738"><span id="translatedtitle">Genomic duplication resulting in increased copy number of genes encoding the sister <span class="hlt">chromatid</span> cohesion complex conveys clinical consequences distinct from Cornelia de Lange</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yan, Jiong; Zhang, Feng; Brundage, Ellen; Scheuerle, Angela; Lanpher, Brendan; Erickson, Robert P.; Powis, Zoe; Robinson, Haynes B.; Trapane, Pamela L.; Stachiw-Hietpas, Danuta; Keppler-Noreuil, Kim M.; Lalani, Seema R.; Sahoo, Trilochan; Chinault, A. Craig; Patel, Ankita; Cheung, Sau Wai; Lupski, James R.</p> <p>2009-01-01</p> <p>Cornelia de Lange Syndrome (CdLS) is a multisystem congenital anomaly disorder. Heterozygous point mutations in three genes (NIPBL, SMC3 and SMC1A), encoding components of the sister <span class="hlt">chromatid</span> cohesion apparatus, are responsible for ∼ 50-60% of CdLS cases. Recent studies have revealed a high degree of genomic rearrangements (e.g. deletions and duplications) in the human genome, which result in gene copy number variations (CNV). CNVs have been associated with a wide range of both Mendelian and complex traits including disease phenotypes such as Charcot-Marie-Tooth type 1A, Pelizaeus-Merzbacher, Parkinson, Alzheimer, autism and schizophrenia. Increased versus decreased copy number of the same gene can potentially cause either similar or different clinical features. We identified duplications on chromosomes 5 or X using genome wide array Comparative Genomic Hybridization (aCGH). The duplicated regions contain either the NIPBL or the SMC1A genes. Junction sequences analyses revealed the involvement of three genomic rearrangement mechanisms. The patients share some common features including mental retardation, developmental delay, sleep abnormalities, and crainofacial and limb defects. The systems affected are the same as in CdLS, but clinical manifestations are distinct from CdLS; particularly the absence of the CdLS facial gestalt. Our results confirm the notion that duplication CNV of genes can be a common mechanism for human genetic diseases. Defining the clinical consequences for a specific gene dosage alteration represents a new “reverse genomics” trend in medical genetics that is reciprocal to the traditional approach of delineation of the common clinical phenotype preceding the discovery of the genetic etiology. PMID:19052029</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=260309','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=260309"><span id="translatedtitle">Minimal influence of G-protein null mutations on ozone-<span class="hlt">induced</span> changes in gene expression, foliar injury, gas-<span class="hlt">exchange</span> and peroxidase activity in Arabidopsis thaliana L</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Ozone uptake by plants leads to an increase in reactive oxygen species (ROS) in the intercellular space of leaves and <span class="hlt">induces</span> signalling processes reported to involve the membrane-bound heterotrimeric G-protein complex. Therefore, potential G-protein-mediated response mechanisms to ozone were compar...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3398457','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3398457"><span id="translatedtitle">Root and shoot gas <span class="hlt">exchange</span> respond additively to moderate ozone and methyl jasmonate without induction of ethylene: ethylene is <span class="hlt">induced</span> at higher O3 concentrations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grantz, D.A.; Vu, H.-B.</p> <p>2012-01-01</p> <p>The available literature is conflicting on the potential protection of plants against ozone (O3) injury by exogenous jasmonates, including methyl jasmonate (MeJA). Protective antagonistic interactions of O3 and MeJA have been observed in some systems and purely additive effects in others. Here it is shown that chronic exposure to low to moderate O3 concentrations (4–114 ppb; 12 h mean) and to MeJA <span class="hlt">induced</span> additive reductions in carbon assimilation (A n) and root respiration (R r), and in calculated whole plant carbon balance. Neither this chronic O3 regime nor MeJA <span class="hlt">induced</span> emission of ethylene (ET) from the youngest fully expanded leaves. ET emission was <span class="hlt">induced</span> by acute 3 h pulse exposure to much higher O3 concentrations (685 ppb). ET emission was further enhanced in plants treated with MeJA. Responses of growth, allocation, photosynthesis, and respiration to moderate O3 concentrations and to MeJA appear to be independent and additive, and not associated with emission of ET. These results suggest that responses of Pima cotton to environmentally relevant O3 are not mediated by signalling pathways associated with ET and MeJA, though these pathways are <span class="hlt">inducible</span> in this species and exhibit a synergistic O3×MeJA interaction at very high O3 concentrations. PMID:22563119</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948829','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948829"><span id="translatedtitle">Multiple Rad52-Mediated Homology-Directed Repair Mechanisms Are Required to Prevent Telomere Attrition-<span class="hlt">Induced</span> Senescence in Saccharomyces cerevisiae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>Most human somatic cells express insufficient levels of telomerase, which can result in telomere shortening and eventually senescence, both of which are hallmarks of ageing. Homology-directed repair (HDR) is important for maintaining proper telomere function in yeast and mammals. In Saccharomyces cerevisiae, Rad52 is required for almost all HDR mechanisms, and telomerase-null cells senesce faster in the absence of Rad52. However, its role in preventing accelerated senescence has been unclear. In this study, we make use of rad52 separation-of-function mutants to find that multiple Rad52-mediated HDR mechanisms are required to delay senescence, including break-<span class="hlt">induced</span> replication and sister <span class="hlt">chromatid</span> recombination. In addition, we show that misregulation of histone 3 lysine 56 acetylation, which is known to be defective in sister <span class="hlt">chromatid</span> recombination, also causes accelerated senescence. We propose a model where Rad52 is needed to repair telomere attrition-<span class="hlt">induced</span> replication stress. PMID:27428329</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846941','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846941"><span id="translatedtitle">Pendrin, an anion <span class="hlt">exchanger</span> on lung epithelial cells, could be a novel target for lipopolysaccharide-<span class="hlt">induced</span> acute lung injury mice</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jia, Chun-E; Jiang, Dingyuan; Dai, Huaping; Xiao, Fei; Wang, Chen</p> <p>2016-01-01</p> <p>Objective: The aim of this study is to evaluate the role of pendrin in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and to explore whether pendrin expression existing on alveolar cells. Methods: ALI C57BL/6 mice model <span class="hlt">induced</span> by lipopolysaccharide (LPS) was established. The expression of pendrin in lung was analyzed by RT-PCR and western blotting methods, the changes of lung inflammatory parameters and pathology were observed, the cellular distribution of pendrin in the lung was determined using immunofluorescence. Statistical comparisons between groups were made by two-tailed Student’s t-test. Results: Enhanced expression of the slc26a4 gene and production of pendrin in lungs of LPS-<span class="hlt">induced</span> ALI mice were confirmed. In comparison with vehicle-control mice, methazolamide treatment mitigated lung inflammatory parameters and pathology. IL-6 and MCP-1 in lung tissues and BALF in methazolamide-treated mice were statistically decreased. Methazolamide treatment had significant effect on the total protein concentration in the BALF and the ratio of lung wet/dry weight. The percentage of macrophages in the BALF was increased. There was a low expression of pendrin in ATII. Conclusions: Pendrin may be involved in pathological process of LPS-<span class="hlt">induced</span> ALI. Inhibition of the pendrin function could be used to treat ALI. Airway epithelial cell may be a valuable therapeutic target for discovering and developing new drugs and/or new therapeutic strategies for the treatment of ALI/ARDS. PMID:27158384</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3570780','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3570780"><span id="translatedtitle">Nucleotide-<span class="hlt">induced</span> conformational changes of tetradecameric GroEL mapped by H/D <span class="hlt">exchange</span> monitored by FT-ICR mass spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Qian; Chen, Jin; Kuwajima, Kunihiro; Zhang, Hui-Min; Xian, Feng; Young, Nicolas L.; Marshall, Alan G.</p> <p>2013-01-01</p> <p>Here we employ hydrogen/deuterium <span class="hlt">exchange</span> mass spectrometry (HDX-MS) to access E. coli chaperonin GroEL conformation. The ~800 kDa tetradecameric GroEL plays an essential role in the proper folding of many proteins. Previous studies of the structural dynamics of GroEL upon ATP binding have been inconsistent, showing either minimal or major allosteric changes. Our results, based on the native, non-mutated, protein under physiological conditions in solution demonstrate substantial changes in conformation and/or flexibility upon ATP binding. We capture the pivotal step in its functional cycle by use of a non-hydrolyzable ATP analog, ATPγS, to mimic the ATP-bound GroEL state. Comparison of HDX-MS results for apo GroEL and GroEL-ATPγS enables the characterization of the nucleotide-regulated conformational changes throughout the entire protein with high sequence resolution. The 14-mer GroEL complex is the largest protein assembly yet accessed by HDX-MS, with sequence resolution of segments of as few as five amino acids. PMID:23409238</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPS...196.9884U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPS...196.9884U"><span id="translatedtitle">Pt/C catalyst degradation in proton <span class="hlt">exchange</span> membrane fuel cells due to high-frequency potential cycling <span class="hlt">induced</span> by switching power converters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uno, Masatoshi; Tanaka, Koji</p> <p></p> <p>Proton <span class="hlt">exchange</span> membrane fuel cells are operated using switching power converters that produce high-frequency ripple currents. These ripples cause high-frequency potential cycling of cells, which is believed to lead premature deterioration in the electrochemical surface area (ECA) of Pt/C catalysts. The qualitative relationship between ECA losses and the frequency of potential cycling was investigated in the range of 1 Hz to 1 kHz. For frequencies higher than 100 Hz, ECA losses were comparable with those at the potential hold condition. However, for lower frequencies, ECA decreased significantly with decreasing frequency. TEM observations showed that there was marked Pt particle growth for the 1-Hz cycling condition, whereas particle size distributions at 100 Hz and potential hold conditions were comparable. The currents associated with Pt oxidation and reduction during potential cycling were also investigated at various potentials and frequencies, and the charges associated with Pt loss (Δ Q) were determined by integrating the measured current. A correlation between the ECA trend and Δ Q was observed. The results obtained in this study are considered informative for electrical engineering research, because it relates to the design of switching power converters that do not negatively influence the Pt/C catalyst durability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JAP...111e3904H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JAP...111e3904H"><span id="translatedtitle">Field-<span class="hlt">induced</span> transitions from negative to positive <span class="hlt">exchange</span> bias in nanoparticles with inverted ferromagnetic-antiferromagnetic core-shell morphology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Yong; Wu, Guo-Zhen; Liu, Yan; Du, An</p> <p>2012-03-01</p> <p>In an antiferromagnetic (core)/ferromagnetic (shell) nanoparticle, the transition behaviors from negative (NEB) to positive <span class="hlt">exchange</span> bias (PEB) at low temperature after field cooling are studied in detail. The NEB field may exhibit an oscillatory behavior due to the competition between interfacial coupling and cooling field. The critical cooling fields, at which the transitions occur, exhibit a logarithmic decrement with the decrease of interfacial coupling, but indicate a linear decrease with the decrease of antiferromagnetic coupling or with the further dilution in the antiferromagnetic core. With the further increase of cooling field, the PEB field increases linearly and finally levels off. Moreover, the weaker antiferromagnetic coupling may enhance the NEB field value, whereas the suppression of PEB may be observed by diluting the antiferromagnetic core. The magnetization reversal by coherent rotation strongly depends on the variation of the magnetic parameters, because its occurrence just needs to consume a lower additional energy, which is the main reason for these unique phenomena. We have shed new light on the microscopic origin of the peculiar magnetic properties in the nanoparticles with such an inverted magnetic structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9237771','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9237771"><span id="translatedtitle">Damage proneness <span class="hlt">induced</span> by genomic DNA demethylation in mammalian cells cultivated in vitro.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perticone, P; Gensabella, G; Cozzi, R</p> <p>1997-07-01</p> <p>Variations in the genomic DNA methylation level have been shown to be an epigenetic inheritable modification affecting, among other targets, the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) rate in mammalian cells in vitro. The inheritable increase in SCE rate in affected cell populations appears as a puzzling phenomenon in view of the well established relation between SCE and both mutagenesis and carcinogenesis. In the present work we demonstrate that, in a treated cell population, demethylation could be responsible for the inheritable induction of damage proneness affecting both damage induction and repair. Normal and ethionine or azacytidine treated Chinese hamster ovary cells, subclone K1 (CHO-K1), were challenged with UV light (UV) or mitomycin-C (MMC) at different times from the demethylating treatment. The SCE rate was measured with two main objects in view: (i) the induction of synergism or additivity in combined treatments, where mutagen (UV or MMC) pulse is supplied from 0 to 48 h after the end of the demethylating treatment; and (ii) the pattern of damage extinction, for the duration of up to six cell cycles after the end of the combined (demethylating agent + mutagen) treatment. Results indicate both a synergism in SCE induction by mutagens in demethylated cells even if supplied up to four cell cycles after the end of the demethylation treatment and a delay in recovery of <span class="hlt">induced</span> damage, compared with normally methylated cells. These data are discussed in the light of the supposed mechanism of SCE increase and of the possible biological significance in terms of mutagenesis and carcinogenesis. PMID:9237771</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93r4430M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93r4430M"><span id="translatedtitle">Negative <span class="hlt">exchange</span> bias in single-phase D y1 -xN dxCr O3 <span class="hlt">induced</span> by Nd doping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDannald, A.; dela Cruz, C. R.; Seehra, M. S.; Jain, M.</p> <p>2016-05-01</p> <p>Observation of significant negative <span class="hlt">exchange</span> bias (HE) is reported in solid solutions of single-phase samples of D y1 -xN dxCr O3 for x = 0.33 ,0.67 , and 1 with corresponding Néel temperatures at TNCr= 175 K ,200 K , and 225 K, respectively, and the spin-reorientation transitions TS R at 48 K, 58 K, and 38 K, respectively. In contrast, no HE was observed for the sample with x =0 (i.e., DyCr O3 ) shows no HE below its TNCr= 145 K , and no reorientation of spins at lower temperatures was observed. More importantly, the (negative) HE for the x = 0.33 ,0.67 , and 1 samples is observed only in the temperature range between TN and TS R with the corresponding observation of magnetic coercivity. These results show that the canted antiferromagnetic Γ7 ,Cr structure of the C r3 + moments present between TNCr and TS R is essential for the observed HE. By comparing this result to the literature, common features of single-phase materials with HE were identified. The present bulk powder samples were prepared by the citrate method and structurally characterized by x-ray diffraction and Raman spectroscopy techniques. Neutron diffraction measurements for the x = 0.33 ,0.67 , and 1 samples at select temperatures were done to verify the presence of the Γ7 ,Cr structure between TNCr and TS R and the Γ1 ,Cr structure (with no canting of C r3 + moments) below TS R.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871701','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871701"><span id="translatedtitle">Release of GTP <span class="hlt">Exchange</span> Factor Mediated Down-Regulation of Abscisic Acid Signal Transduction through ABA-<span class="hlt">Induced</span> Rapid Degradation of RopGEFs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Waadt, Rainer; Schroeder, Julian I.</p> <p>2016-01-01</p> <p>The phytohormone abscisic acid (ABA) is critical to plant development and stress responses. Abiotic stress triggers an ABA signal transduction cascade, which is comprised of the core components PYL/RCAR ABA receptors, PP2C-type protein phosphatases, and protein kinases. Small GTPases of the ROP/RAC family act as negative regulators of ABA signal transduction. However, the mechanisms by which ABA controls the behavior of ROP/RACs have remained unclear. Here, we show that an Arabidopsis guanine nucleotide <span class="hlt">exchange</span> factor protein RopGEF1 is rapidly sequestered to intracellular particles in response to ABA. GFP-RopGEF1 is sequestered via the endosome-prevacuolar compartment pathway and is degraded. RopGEF1 directly interacts with several clade A PP2C protein phosphatases, including ABI1. Interestingly, RopGEF1 undergoes constitutive degradation in pp2c quadruple abi1/abi2/hab1/pp2ca mutant plants, revealing that active PP2C protein phosphatases protect and stabilize RopGEF1 from ABA-mediated degradation. Interestingly, ABA-mediated degradation of RopGEF1 also plays an important role in ABA-mediated inhibition of lateral root growth. The presented findings point to a PP2C-RopGEF-ROP/RAC control loop model that is proposed to aid in shutting off ABA signal transduction, to counteract leaky ABA signal transduction caused by “monomeric” PYL/RCAR ABA receptors in the absence of stress, and facilitate signaling in response to ABA. PMID:27192441</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://epi.grants.cancer.gov/pharm/pharmacoepi_db/indiana.html','NCI'); return false;" href="http://epi.grants.cancer.gov/pharm/pharmacoepi_db/indiana.html"><span id="translatedtitle">Indiana Health Information <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p>The Indiana Health Information <span class="hlt">Exchange</span> is comprised of various Indiana health care institutions, established to help improve patient safety and is recognized as a best practice for health information <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863101','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863101"><span id="translatedtitle">Charge <span class="hlt">exchange</span> system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Anderson, Oscar A.</p> <p>1978-01-01</p> <p>An improved charge <span class="hlt">exchange</span> system for substantially reducing pumping requirements of excess gas in a controlled thermonuclear reactor high energy neutral beam injector. The charge <span class="hlt">exchange</span> system utilizes a jet-type blanket which acts simultaneously as the charge <span class="hlt">exchange</span> medium and as a shield for reflecting excess gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1064936','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1064936"><span id="translatedtitle">Redox <span class="hlt">Exchange</span> <span class="hlt">Induced</span> MnO<sub>2</sub> Nanoparticle Enrichment in Poly(3,4-ethylenedioxythiophene) Nanowires for Electrochemical Energy Storage</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, R.; Duay, Jonathon; Lee, Sang Bok</p> <p>2010-06-30</p> <p>MnO<sub>2</sub> nanoparticle enriched poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires are fabricated by simply soaking the PEDOT nanowires in potassium permanganate (KMnO<sub>4</sub>) solution. The structures of these MnO<sub>2</sub> nanoparticle enriched PEDOT nanowires are characterized by SEM and TEM, which show that the MnO<sub>2</sub> 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 MnO<sub>2</sub> nanoparticles into the nanoscale pores of the PEDOT nanowires are most likely triggered by the reduction of KMnO<sub>4</sub> via the redox <span class="hlt">exchange</span> of permanganate ions with the functional group on PEDOT. Varying the concentrations of KMnO<sub>4</sub> and the reaction time controls the loading amount and size of the MnO<sub>2</sub> nanoparticles. Cyclic voltammetry and galvanostatic charge-discharge are used to characterize the electrochemical properties of these MnO<sub>2</sub> nanoparticle loaded PEDOT nanowires. Due to their extremely high exposed surface area with nanosizes, the pristine MnO<sub>2</sub> nanoparticles in these MnO<sub>2</sub> nanoparticle enriched PEDOT nanowires show very high specific capacitance (410 F/g) as the supercapacitor electrode materials as well as high Li<sup>+</sup> 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 MnO<sub>2</sub> nanoparticles and prevents them from agglomerating. These synergic properties enable the MnO<sub>2</sub> nanoparticle enriched PEDOT nanowires to be promising electrode materials for supercapacitors and</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1435098','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1435098"><span id="translatedtitle">Lipid <span class="hlt">exchange</span> between membranes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jähnig, F</p> <p>1984-01-01</p> <p>The <span class="hlt">exchange</span> of lipid molecules between vesicle bilayers in water and a monolayer forming at the water surface was investigated theoretically within the framework of thermodynamics. The total number of <span class="hlt">exchanged</span> molecules was found to depend on the bilayer curvature as expressed by the vesicle radius and on the boundary condition for <span class="hlt">exchange</span>, i.e., whether during <span class="hlt">exchange</span> the radius or the packing density of the vesicles remains constant. The boundary condition is determined by the rate of flip-flop within the bilayer relative to the rate of <span class="hlt">exchange</span> between bi- and monolayer. If flip-flop is fast, <span class="hlt">exchange</span> is independent of the vesicle radius; if flip-flop is slow, <span class="hlt">exchange</span> increases with the vesicle radius. Available experimental results agree with the detailed form of this dependence. When the theory was extended to <span class="hlt">exchange</span> between two bilayers of different curvature, the direction of <span class="hlt">exchange</span> was also determined by the curvatures and the boundary conditions for <span class="hlt">exchange</span>. Due to the dependence of the boundary conditions on flip-flop and, consequently, on membrane fluidity, <span class="hlt">exchange</span> between membranes may partially be regulated by membrane fluidity. PMID:6518251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1004628','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1004628"><span id="translatedtitle">Spin polarization and <span class="hlt">exchange</span> coupling of Cu and Mn atoms in paramagnetic CuMn diluted alloys <span class="hlt">induced</span> by a Co layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abes, M.; Arena, D.; Atkinson, D.; Tanner, B.K.; Charlton, T.R.; Langridge, S.; Hase, T.P.A.; Ali, M.; Marrows, C.H.; Hickey, B.J.; Neudert, Al; Hicken, R.J.; Wilkins, S.B.; Mirone, A.; Lebegue, S.</p> <p>2010-11-09</p> <p>Using the surface, interface, and element specificity of x-ray resonant magnetic scattering in combination with x-ray magnetic circular dichroism, we have spatially resolved the magnetic spin polarization, and the associated interface proximity effect, in a Mn-based high-susceptibility material close to a ferromagnetic Co layer. We have measured the magnetic polarization of Mn and Cu3d electrons in paramagnetic CuMn alloy layers in [Co/Cu(x)/CuMn/Cu(x)]{sub 20} multilayer samples with varying copper layer thicknesses from x=0 to 25 {angstrom}. The size of the Mn and CuL{sub 2,3} edge dichroism shows a decrease in the Mn-<span class="hlt">induced</span> polarization for increasing copper thickness indicating the dominant interfacial nature of the Cu and Mn spin polarization. The Mn polarization is much higher than that of Cu. Evidently, the Mn moment is a useful probe of the local spin density. Mn atoms appear to be coupled antiferromagnetically with the Co layer below x = 10 {angstrom} and ferromagnetically coupled above. In contrast, the interfacial Cu atoms remain ferromagnetically aligned to the Co layer for all thicknesses studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905725','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4905725"><span id="translatedtitle">Minimal influence of G-protein null mutations on ozone-<span class="hlt">induced</span> changes in gene expression, foliar injury, gas <span class="hlt">exchange</span> and peroxidase activity in Arabidopsis thaliana L</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Booker, Fitzgerald; Burkey, Kent; Morgan, Patrick; Fiscus, Edwin; Jones, Alan</p> <p>2016-01-01</p> <p>Ozone (O3) uptake by plants leads to an increase in reactive oxygen species (ROS) in the intercellular space of leaves and <span class="hlt">induces</span> signalling processes reported to involve the membrane-bound heterotrimeric G-protein complex. Therefore, potential G-protein-mediated response mechanisms to O3 were compared between Arabidopsis thaliana L. lines with null mutations in the α- and β-subunits (gpa1-4, agb1-2 and gpa1-4/agb1-2) and Col-0 wild-type plants. Plants were treated with a range of O3 concentrations (5, 125, 175 and 300 nL L−1) for 1 and 2 d in controlled environment chambers. Transcript levels of GPA1, AGB1 and RGS1 transiently increased in Col-0 exposed to 125 nL L−1 O3 compared with the 5 nL L−1 control treatment. However, silencing of α and β G-protein genes resulted in little alteration of many processes associated with O3 injury, including the induction of ROS-signalling genes, increased leaf tissue ion leakage, decreased net photosynthesis and stomatal conductance, and increased peroxidase activity, especially in the leaf apoplast. These results indicated that many responses to O3 stress at physiological levels were not detectably influenced by α and β G-proteins. PMID:21988569</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3826130','PMC'); return false;" href="http://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://hdl.handle.net/2060/20080009511','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080009511"><span id="translatedtitle">Nonsurvivable momentum <span class="hlt">exchange</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roder, Russell (Inventor); Ahronovich, Eliezer (Inventor); Davis, III, Milton C. (Inventor)</p> <p>2007-01-01</p> <p>A demiseable momentum <span class="hlt">exchange</span> system includes a base and a flywheel rotatably supported on the base. The flywheel includes a web portion defining a plurality of web openings and a rim portion. The momentum <span class="hlt">exchange</span> system further includes a motor for driving the flywheel and a cover for engaging the base to substantially enclose the flywheel. The system may also include components having a melting temperature below 1500 degrees Celsius. The momentum <span class="hlt">exchange</span> system is configured to demise on reentry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8687133','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8687133"><span id="translatedtitle">Studies on genotoxicity of orally administered crocidolite asbestos in rats: implications for ingested asbestos <span class="hlt">induced</span> carcinogenesis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Varga, C; Pocsai, Z; Horváth, G; Timbrell, V</p> <p>1996-01-01</p> <p>The early genotoxic action of oral exposure to UICC crocidolite asbestos fibres was studied in different short-term tests. Fischer-344 rats were gavaged with 50 mg/b.w.kg untreated asbestos fibres and fibres which had been allowed to adsorb benzo(a)pyrene molecules from extremely low concentration (0.25-2.5 microg/ml) aqueous solutions. This system can be considered a model for the drinking of potable water contaminated by asbestos fibres together with biologically active organic micro-pollutants. The Ames Salmonella mutagenicity assay was performed on concentrated urine and serum samples of treated animals. The formation of micronuclei and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> was also studied in the bone marrow of the exposed rats. The micronucleus analysis indicated marginal genotoxic activity only upon treatment with crocidolite prepared from the solution of 1 microg/ml. A dose-dependent increase was, however, demonstrated in the sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> frequency upon treatment with benzo(a)pyrene coated fibres. These experiments suggest the acute cogenotoxic activity of such fibres in orally exposed animals. PMID:8687133</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=text&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtext','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850000419&hterms=text&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtext"><span id="translatedtitle">Text <span class="hlt">Exchange</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snyder, W. V.; Hanson, R. J.</p> <p>1986-01-01</p> <p>Text <span class="hlt">Exchange</span> System (TES) <span class="hlt">exchanges</span> and maintains organized textual information including source code, documentation, data, and listings. System consists of two computer programs and definition of format for information storage. Comprehensive program used to create, read, and maintain TES files. TES developed to meet three goals: First, easy and efficient <span class="hlt">exchange</span> of programs and other textual data between similar and dissimilar computer systems via magnetic tape. Second, provide transportable management system for textual information. Third, provide common user interface, over wide variety of computing systems, for all activities associated with text <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED510312.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED510312.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2008</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2008-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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://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://eric.ed.gov/?q=social+AND+exchange+AND+theory&pg=7&id=ED306612','ERIC'); return false;" href="http://eric.ed.gov/?q=social+AND+exchange+AND+theory&pg=7&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('http://eric.ed.gov/?q=social+AND+exchange+AND+theory&pg=6&id=EJ965736','ERIC'); return false;" href="http://eric.ed.gov/?q=social+AND+exchange+AND+theory&pg=6&id=EJ965736"><span id="translatedtitle">Building Relationships through <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Primavera, Angi; Hall, Ellen</p> <p>2011-01-01</p> <p>From the moment of birth, children form and develop relationships with others in their world based on <span class="hlt">exchange</span>. Children recognize that engaging in such encounters offers them the opportunity to enter into a relationship with another individual and to nurture that relationship through the <span class="hlt">exchange</span> of messages and gifts, items and ideas. At Boulder…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539343.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539343.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2011</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2011-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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/ED539331.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539331.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2012</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2012-01-01</p> <p>"Higher Education <span class="hlt">Exchange</span>" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education <span class="hlt">Exchange</span>" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED497932.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED497932.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2007</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>2007-01-01</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>" discuss the concept of growing public scholars; each contribution incorporates a student component. Articles include: (1) "Foreword"…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED274569.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED274569.pdf"><span id="translatedtitle">Money and <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>Walstad, William B.; And Others</p> <p>1982-01-01</p> <p>This teaching guide begins with an explanation of the role of money in the economy, focusing on its circulation or <span class="hlt">exchange</span>. The use of money as a unit of account, a store of value, and a medium of <span class="hlt">exchange</span> are explained. Three brief teaching units are included. The grade K-2 unit, "Money Counts," provides games and activities which develop the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1204094','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1204094"><span id="translatedtitle"><span class="hlt">Exchange</span> of Spacer Regions between Rrna Operons in Escherichia Coli</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harvey, S.; Hill, C. W.</p> <p>1990-01-01</p> <p>The Escherichia coli rRNA operons each have one of two types of spacer separating the 16S and 23S coding regions. The spacers of four operons encode tRNA(Glu2) and the other three encode both tRNA(Ile) and tRNA(Ala 1 B). We have prepared a series of mutants in which the spacer region of a particular rrn operon has been replaced by the opposite type. Included among these were a mutant retaining only a single copy of the tRNA(Glu2) spacer (at rrnG) and another retaining only a single copy of the tRNA(Ile)-tRNA(Ala 1 B) spacer (at rrnA). While both mutants grew more slowly than controls, the mutant deficient in tRNA(Glu2) spacers was more severely affected. At a frequency of 6 X 10(-5), these mutants phenotypically reverted to faster growing types by increasing the copy number of the deficient spacer. In most of these phenotypic revertants, the deficient spacer type appeared in a rrn operon which previously contained the surplus type, bringing the ratio of spacer types closer to normal. In a few cases, these spacer changes were accompanied by an inversion of the chromosomal material between the donor and recipient rrn operons. Two examples of inversion of one-half of the E. coli chromosome between rrnG and rrnH were observed. The correlation of spacer change with inversion indicated that, in these particular cases, the change was due to an intrachromatid gene conversion event accompanied by a reciprocal crossover rather than reciprocal <span class="hlt">exchange</span> between sister <span class="hlt">chromatids</span>. PMID:2168847</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3608494','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3608494"><span id="translatedtitle">Central role of the <span class="hlt">exchange</span> factor GEF-H1 in TNF-α–<span class="hlt">induced</span> sequential activation of Rac, ADAM17/TACE, and RhoA in tubular 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>Waheed, Faiza; Dan, Qinghong; Amoozadeh, Yasaman; Zhang, Yuqian; Tanimura, Susumu; Speight, Pam; Kapus, András; Szászi, Katalin</p> <p>2013-01-01</p> <p>Transactivation of the epidermal growth factor receptor (EGFR) by tumor necrosis factor-α (TNF-α) is a key step in mediating RhoA activation and cytoskeleton and junction remodeling in the tubular epithelium. In this study we explore the mechanisms underlying TNF-α–<span class="hlt">induced</span> EGFR activation. We show that TNF-α stimulates the TNF-α convertase enzyme (TACE/a disintegrin and metalloproteinase-17), leading to activation of the EGFR/ERK pathway. TACE activation requires the mitogen-activated protein kinase p38, which is activated through the small GTPase Rac. TNF-α stimulates both Rac and RhoA through the guanine nucleotide <span class="hlt">exchange</span> factor (GEF)-H1 but by different mechanisms. EGFR- and ERK-dependent phosphorylation at the T678 site of GEF-H1 is a prerequisite for RhoA activation only, whereas both Rac and RhoA activation require GEF-H1 phosphorylation on S885. Of interest, GEF-H1-mediated Rac activation is upstream from the TACE/EGFR/ERK pathway and regulates T678 phosphorylation. We also show that TNF-α enhances epithelial wound healing through TACE, ERK, and GEF-H1. Taken together, our findings can explain the mechanisms leading to hierarchical activation of Rac and RhoA by TNF-α through a single GEF. This mechanism could coordinate GEF functions and fine-tune Rac and RhoA activation in epithelial cells, thereby promoting complex functions such as sheet migration. PMID:23389627</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005EPJB...45..155M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005EPJB...45..155M&link_type=ABSTRACT"><span id="translatedtitle">New Trends in Magnetic <span class="hlt">Exchange</span> Bias</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois</p> <p>2005-05-01</p> <p>The study of layered magnetic structures is one of the hottest topics in magnetism due to the growing attraction of applications in magnetic sensors and magnetic storage media, such as random access memory. For almost half a century, new discoveries have driven researchers to re-investigate magnetism in thin film structures. Phenomena such as giant magnetoresistance, tunneling magnetoresistance, <span class="hlt">exchange</span> bias and interlayer <span class="hlt">exchange</span> coupling led to new ideas to construct devices, based not only on semiconductors but on a variety of magnetic materials Upon cooling fine cobalt particles in a magnetic field through the Néel temperature of their outer antiferromagnetic oxide layer, Meiklejohn and Bean discovered <span class="hlt">exchange</span> bias in 1956. The <span class="hlt">exchange</span> bias effect through which an antiferromagnetic AF layer can cause an adjacent ferromagnetic F layer to develop a preferred direction of magnetization, is widely used in magnetoelectronics technology to pin the magnetization of a device reference layer in a desired direction. However, the origin and effects due to <span class="hlt">exchange</span> interaction across the interface between antiferromagneic and ferromagnetic layers are still debated after about fifty years of research, due to the extreme difficulty associated with the determination of the magnetic interfacial structure in F/AF bilayers. Indeed, in an AF/F bilayer system, the AF layer acts as “the invisible man” during conventional magnetic measurements and the presence of the <span class="hlt">exchange</span> coupling is evidenced indirectly through the unusual behavior of the adjacent F layer. Basically, the coercive field of the F layer increases in contact with the AF and, in some cases, its hysteresis loop is shifted by an amount called <span class="hlt">exchange</span> bias field. Thus, AF/F <span class="hlt">exchange</span> coupling generates a new source of anisotropy in the F layer. This <span class="hlt">induced</span> anisotropy strongly depends on basic features such as the magnetocrystalline anisotropy, crystallographic and spin structures, defects, domain patterns etc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/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://www.osti.gov/scitech/servlets/purl/1018726','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1018726"><span id="translatedtitle">Heat and mass <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas</p> <p>2011-06-28</p> <p>A mass and heat <span class="hlt">exchanger</span> includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat <span class="hlt">exchange</span> fluid therethrough, wherein heat transfer occurs between the liquid and the heat <span class="hlt">exchange</span> fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/915245','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/915245"><span id="translatedtitle">Heat and mass <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas</p> <p>2007-09-18</p> <p>A mass and heat <span class="hlt">exchanger</span> includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat <span class="hlt">exchange</span> fluid therethrough, wherein heat transfer occurs between the liquid and the heat <span class="hlt">exchange</span> fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5049207','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5049207"><span id="translatedtitle">Microtube strip heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Doty, F.D.</p> <p>1991-10-16</p> <p>This progress report is for the September--October 1991 quarter. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas <span class="hlt">exchangers</span>. These laminar-flow, microtube <span class="hlt">exchangers</span> exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat <span class="hlt">exchanger</span> performance promise to be of enormous significance in advanced engine designs and in cryogenics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17250441','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17250441"><span id="translatedtitle">Anticancer and antimutagenic properties of Acacia nilotica (Linn.) on 7,12-dimethylbenz(a)anthracene-<span class="hlt">induced</span> skin papillomagenesis in Swiss albino mice.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meena, Punar Dutt; Kaushik, Pallavi; Shukla, Shalini; Soni, Anil Kumar; Kumar, Manish; Kumar, Ashok</p> <p>2006-01-01</p> <p>We report the chemopreventive activity of Acacia nilotica (Linn.) gum, flower and leaf aqueous extracts, on 7,12-dimethylbenz(a)anthracene (DMBA) <span class="hlt">induced</span> skin papillomagenesis in male Swiss albino mice. Animals were divided into following groups: Group I (Controls) given DMBA and croton oil, with no extract ; Group II (treatment) animals treated with Acacia nilotica gum (Group II-a) (800 mg/kg body weight), flowers (Group II-b) (800 mg/kg body weight), or leaves (Group II-c) (800 mg/kg body weight) during the peri- and post initiation periods of DMBA and croton oil application. A significant reduction in the values of tumor burden, tumor incidence and cumulative number of papillomas was observed in mice treated by oral gavage with the Acacia nilotica gum, flower and leaf extracts as compared with the control group. The latency period in treatment Group-II (b) and Group-II (c) was significantly increased as compared with the control group. A significant reduction in the frequency of micronuclei was also observed in mice treated by oral gavage with the aqueous extracts, along with significant decrease in total chromosomal aberrations in the form of <span class="hlt">chromatid</span> breaks, chromosome breaks, centric rings, dicentrics, acentric fragments and <span class="hlt">exchange</span>. Treatment with Acacia nilotica flower (Group II-B) and leaf (Group II-C) aqueous extracts by oral gavage for 15 days resulted in a highly significant decrease in the lipid peroxidation (LPO) level in the liver, but this was less evident with the gum (Group II-A) . Conversely, reduced glutathione (GSH) content was observed to be significantly elevated as compared with the control group with leaves (Group II-C) and flowers (Group II-B). The chemopreventive and antimutagenic activity of the leaf extract of Acacia nilotica was most significant followed by the flower extract and then by gum. PMID:17250441</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7050066','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7050066"><span id="translatedtitle">In vitro effect of fenthion on human lymphocytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rani, M.V.U. ); Rao, M.S. )</p> <p>1991-08-01</p> <p>Fenthion is an organophosphorus insecticide which is extensively used in control of leaf hoppers, cutworms, mites on vegetable crops. It has been reported that organophosphorus pesticides cause a significant increase in sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in mammalian cell lines. A significant increase of chromosomal aberrations has been reported in rural population exposed to pesticides. Organosphosphorus pesticides malathion, diazinon, dimethoate, phosdrin and dursban <span class="hlt">induced</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span> in human lymphoid cells. <span class="hlt">Exchange</span> type of aberration has been reported in fluoriculturist who were exposed to organophosphorus, organochlorine pesticides. In the present investigation an attempt has been made to evaluate the cytogenetic effect of fenthion in human lymphocyte cultures in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5334634','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5334634"><span id="translatedtitle">Outdoor heat <span class="hlt">exchanger</span> section</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kessler, A.F.; Smiley, W.A. III; Wendt, M.E.</p> <p>1988-02-09</p> <p>An outdoor section for an air conditioning system is described comprising: a compressor; a heat <span class="hlt">exchanger</span>; a cabinet having an upper cabinet section, a lower cabinet section and a louvered lower section top cover, the heat <span class="hlt">exchanger</span> and the compressor being housed in the lower cabinet section and the upper cabinet section having a solid top which overlies the louvers in the lower section top cover; and a fan disposed in the lower cabinet section to draw air through the sides of the lower cabinet section and through the heat <span class="hlt">exchanger</span> housed therein, the fan discharging air, after having been drawn through the heat <span class="hlt">exchanger</span>, upward through the louvers in the lower cabinet section top cover and into the interior of the upper cabinet section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.nlm.nih.gov/medlineplus/ency/presentations/100018_1.htm','NIH-MEDLINEPLUS'); return false;" href="https://www.nlm.nih.gov/medlineplus/ency/presentations/100018_1.htm"><span id="translatedtitle"><span class="hlt">Exchange</span> transfusion - series (image)</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... her back, usually under a radiant warmer. The umbilical vein is catheterized with a fluid-filled catheter. ... plasma is injected. After the <span class="hlt">exchange</span> transfusion, an umbilical catheter may be left in place in case ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873599','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873599"><span id="translatedtitle">Active microchannel heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA</p> <p>2001-01-01</p> <p>The present invention is an active microchannel heat <span class="hlt">exchanger</span> with an active heat source and with microchannel architecture. The microchannel heat <span class="hlt">exchanger</span> has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat <span class="hlt">exchanger</span> chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat <span class="hlt">exchanger</span> chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1183339','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1183339"><span id="translatedtitle">Anion <span class="hlt">exchange</span> polymer electrolytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Yu Seung; Kim, Dae Sik</p> <p>2015-06-02</p> <p>Anion <span class="hlt">exchange</span> polymer electrolytes that include guanidinium functionalized polymers may be used as membranes and binders for electrocatalysts in preparation of anodes for electrochemical cells such as solid alkaline fuel cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22391356','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22391356"><span id="translatedtitle">Charge-<span class="hlt">exchange</span> reaction by Reggeon <span class="hlt">exchange</span> and W{sup +}W{sup −}-fusion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schicker, R.</p> <p>2015-04-10</p> <p>Charge-<span class="hlt">exchange</span> reactions at high energies are examined. The existing cross section data on the Reggeon <span class="hlt">induced</span> reaction pp → n + Δ{sup ++} taken at the ZGS and ISR accelerators are extrapolated to the energies of the RHIC and LHC colliders. The interest in the charge-<span class="hlt">exchange</span> reaction <span class="hlt">induced</span> by W{sup ±}-fusion is presented, and the corresponding QCD-background is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10172832','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10172832"><span id="translatedtitle">Data <span class="hlt">exchange</span> in metrology.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Badger, P</p> <p>1996-01-01</p> <p>The adoption of the directives 71/316/EEC on measuring instruments and 90/384/EEC on non-automatic weighing instruments has resulted in a considerable quantity of certificates to be <span class="hlt">exchanged</span> between the Central Metrological Authorities and the Local Metrological Authorities, in the member states. This requirement to <span class="hlt">exchange</span> data, prompted the setting up of the WELMEC working group, to explore how computerisation could help the member states perform their tasks. PMID:10172832</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6233867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6233867"><span id="translatedtitle">Microtube Strip Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Doty, F.D.</p> <p>1990-12-27</p> <p>Doty Scientific (DSI) believes their Microtube-Strip Heat <span class="hlt">Exchanger</span> will contribute significantly to (a) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (b) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (c) high-efficiency cryogenic gas separation schemes for CO{sub 2} removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat <span class="hlt">exchangers</span> for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98%, and relative pressure drops below 0.1% with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat <span class="hlt">exchanger</span> bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat <span class="hlt">exchanger</span> bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat <span class="hlt">exchanger</span>; construct dies and fixtures for prototype heat <span class="hlt">exchanger</span>; construct 100 MTS modules; assemble 8-10 prototype MTS heat <span class="hlt">exchangers</span>; test prototype MTS heat <span class="hlt">exchanger</span>; and verify test through independent means. 7 refs., 9 figs. 1 tab. (CK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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('http://www.osti.gov/scitech/servlets/purl/873481','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873481"><span id="translatedtitle">Radial flow heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Valenzuela, Javier</p> <p>2001-01-01</p> <p>A radial flow heat <span class="hlt">exchanger</span> (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat <span class="hlt">exchangers</span> may be stacked to achieve a modular heat <span class="hlt">exchange</span> assembly (300). Certain heat <span class="hlt">exchangers</span> in the assembly may be designed slightly differently than other heat <span class="hlt">exchangers</span> to address changes in fluid properties during transport through the heat <span class="hlt">exchanger</span>, so as to enhance overall thermal effectiveness of the assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5462064','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5462064"><span id="translatedtitle">Vacuum powered heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ruffolo, R.F.</p> <p>1986-06-24</p> <p>In an internal combustion engine including an oil lubrication system, a liquid cooling system, and an improved air intake system is described. The improved air intake system comprises: a housing including a first opening in one end, which opening is open to the atmosphere and a second opening comprising an air outlet opening in the other end open to the air intake manifold of the engine, a heat <span class="hlt">exchanger</span> positioned in the first opening. The heat <span class="hlt">exchanger</span> consists of a series of coils positioned in the flow path of the atmospheric air as it enters the housing, the heat <span class="hlt">exchanger</span> being fluidly connected to either the engine lubrication system or the cooling system to provide a warm heat source for the incoming air to the housing, acceleration means positioned in the housing downstream of the heat <span class="hlt">exchanger</span>, the acceleration means comprising a honeycomb structure positioned across the air intake flow path. The honey-comb structure includes a multitude of honey combed mini-venturi cells through which the heated air flows in an accelerated mode, a removable air filter positioned between the heat <span class="hlt">exchanger</span> and the acceleration means and a single opening provided in the housing through which the air filter can be passed and removed, and additional openings in the housing positioned downstream of the heat <span class="hlt">exchanger</span> and upstream of the air filter, the additional openings including removable flaps for opening and closing the openings to control the temperature of the air flowing through the housing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2242475','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2242475"><span id="translatedtitle">Conformational changes of the glucocorticoid receptor ligand binding domain <span class="hlt">induced</span> by ligand and cofactor binding, and the location of cofactor binding sites determined by hydrogen/deuterium <span class="hlt">exchange</span> mass spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Frego, Lee; Davidson, Walter</p> <p>2006-01-01</p> <p>HXMS (hydrogen/deuterium <span class="hlt">exchange</span> mass spectrometry) of the glucocorticoid receptor ligand-binding domain (GR LBD) complexed with the agonist dexamethasone and the antagonist RU-486 is described. Variations in the rates of <span class="hlt">exchange</span> were observed in regions consistent with the published crystal structures of GR LBD complexed with RU-486 when compared with the GR dexamethasone complex. We also report the HXMS results for agonist-bound GR LBD with the coactivator transcriptional intermediary factor 2 (TIF2) and anatagonist-bound GR LBD with nuclear receptor corepressor (NCoR). Alterations in <span class="hlt">exchange</span> rates observed for agonist-bound GR LBD with TIF2 present were consistent with the published crystal structural contacts for the complex. Alterations in <span class="hlt">exchange</span> rates observed for antagonist-bound GR LBD with NCoR were a subset of those observed with TIF2 binding, suggesting a common or overlapping binding site for coactivator and corepressor. PMID:16600964</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2905693','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2905693"><span id="translatedtitle">In Vivo Cytogenetic Studies on Aspartame</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>AlSuhaibani, Entissar S.</p> <p>2010-01-01</p> <p>Aspartame (a-Laspartyl-L-phenylalanine 1-methylester) is a dipeptide low-calorie artificial sweetener that is widely used as a nonnutritive sweetener in foods and drinks. The safety of aspartame and its metabolic breakdown products (phenylalanine, aspartic acid and methanol) was investigated in vivo using chromosomal aberration (CA) test and sister <span class="hlt">chromatid</span> <span class="hlt">exchange</span> (SCE) test in the bone marrow cells of mice. Swiss Albino male mice were exposed to aspartame (3.5, 35, 350 mg/kg body weight). Bone marrow cells isolated from femora were analyzed for chromosome aberrations and sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. Treatment with aspartame <span class="hlt">induced</span> dose dependently chromosome aberrations at all concentrations while it did not <span class="hlt">induce</span> sister <span class="hlt">chromatid</span> <span class="hlt">exchanges</span>. On the other hand, aspartame did not decrease the mitotic index (MI). However, statistical analysis of the results show that aspartame is not significantly genotoxic at low concentration. PMID:20689731</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('http://www.osti.gov/scitech/servlets/purl/5030222','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5030222"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-02-28</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7041653','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7041653"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-03-18</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summary herein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6905451','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6905451"><span id="translatedtitle">Heat <span class="hlt">exchanger</span> restart evaluation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morrison, J.M.; Hirst, C.W.; Lentz, T.F.</p> <p>1992-03-18</p> <p>On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat <span class="hlt">exchanger</span> 4A (HX 4A). The heat <span class="hlt">exchanger</span> was isolated and the plant shutdown. Heat <span class="hlt">exchanger</span> 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat <span class="hlt">exchanger</span> 4A for metallurgical examination. Additional analysis and review of heat <span class="hlt">exchanger</span> leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/691514','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/691514"><span id="translatedtitle">Downhole heat <span class="hlt">exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Culver, G.; Lund, J.W.</p> <p>1999-09-01</p> <p>The downhole heat <span class="hlt">exchanger</span> (DHE) eliminates the problem of disposal of geothermal fluid, since only heat is taken from the well. The <span class="hlt">exchanger</span> consists of a system of pipes or tubes suspended in the well through which clean secondary water is pumped or allowed to circulate by natural convection. These systems offer substantial economic savings over surface heat <span class="hlt">exchangers</span> where a single-well system is adequate (typically less than 0.8 MWt, with well depths up to about 500 ft) and may be economical under certain conditions at well depths to 1500 ft. Several designs have proven successful; but, the most popular are a simple hairpin loop or multiple loops of iron pipe (similar to the tubes in a U-tube and shell <span class="hlt">exchanger</span>) extending to near the well bottom. An experimental design consisting of multiple small tubes with headers at each end suspended just below the water surface appears to offer economic and heating capacity advantages. The paper describes design and construction details and New Zealand`s experience with downhole heat <span class="hlt">exchangers</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948741','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4948741"><span id="translatedtitle">4-Nitroquinoline-1-oxide-<span class="hlt">induced</span> mutagen sensitivity and risk of cutaneous melanoma: a case–control analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Li-E; Li, Chunying; Xiong, Ping; Gershenwald, Jeffrey E.; Prieto, Victor G.; Duvic, Madeleine; Lee, Jeffrey E.; Grimm, Elizabeth A.; Hsu, T.C.; Wei, Qingyi</p> <p>2016-01-01</p> <p>Mutagen sensitivity assay, which measures the enhanced cellular response to DNA damage <span class="hlt">induced</span> in vitro by mutagens/carcinogens, has been used in the study of cancer susceptibility. 4-Nitroquinoline-1-oxide (4-NQO), an ultraviolet (UV) radiation-mimetic chemical, can produce chromosomal breaks in mammalian cells and <span class="hlt">induce</span> cancer. Given the potential role of 4-NQO as the experimental mutagen substituting for UV as the etiological carcinogen of cutaneous melanoma (CM), we tested the hypothesis that cellular sensitivity to 4-NQO is associated with the risk of developing CM in a case–control study of 133 patients with primary CM and 176 cancer-free controls. Short-term blood cultures were treated with 4-NQO at a final concentration of 10 µmol/l for 24 h and scored <span class="hlt">chromatid</span> breaks in 50 well-spread metaphases. Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals. We found that the log-transformed frequency of <span class="hlt">chromatid</span> breaks was significantly higher in 133 patients than in 176 controls (P = 0.004) and was associated with an increased risk for CM (adjusted odds ratio = 1.78, 95% confidence interval: 1.12–2.84) after adjustment for age and sex. Moreover, as the <span class="hlt">chromatid</span> break values increased, the risk for CM increased in a dose-dependent manner (Ptrend = 0.003). Further analysis explored a multiplicative interaction between the sensitivity to 4-NQO and a family history of skin cancer (Pinteraction = 0.004) on the risk of CM. Therefore, our findings suggest that sensitivity to 4-NQO may be a risk factor for the risk of CM, which is more sensitive than UV-<span class="hlt">induced</span> chromosome breaks. PMID:24977319</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863123','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863123"><span id="translatedtitle">Modular heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Culver, Donald W.</p> <p>1978-01-01</p> <p>A heat <span class="hlt">exchanger</span> for use in nuclear reactors includes a heat <span class="hlt">exchange</span> tube bundle formed from similar modules each having a hexagonal shroud containing a large number of thermally conductive tubes which are connected with inlet and outlet headers at opposite ends of each module, the respective headers being adapted for interconnection with suitable inlet and outlet manifold means. In order to adapt the heat <span class="hlt">exchanger</span> for operation in a high temperature and high pressure environment and to provide access to all tube ports at opposite ends of the tube bundle, a spherical tube sheet is arranged in sealed relation across the chamber with an elongated duct extending outwardly therefrom to provide manifold means for interconnection with the opposite end of the tube bundle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048277','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048277"><span id="translatedtitle">Ion <span class="hlt">exchange</span> phenomena</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bourg, I.C.; Sposito, G.</p> <p>2011-05-01</p> <p>Ion <span class="hlt">exchange</span> phenomena involve the population of readily <span class="hlt">exchangeable</span> ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion <span class="hlt">exchange</span> phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4890131','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4890131"><span id="translatedtitle">On <span class="hlt">exchangeable</span> multinomial distributions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>George, E. Olusegun; Cheon, Kyeongmi; Yuan, Yilian; Szabo, Aniko</p> <p>2016-01-01</p> <p>We derive an expression for the joint distribution of <span class="hlt">exchangeable</span> multinomial random variables, which generalizes the multinomial distribution based on independent trials while retaining some of its important properties. Unlike de Finneti's representation theorem for a binary sequence, the <span class="hlt">exchangeable</span> multinomial distribution derived here does not require that the finite set of random variables under consideration be a subset of an infinite sequence. Using expressions for higher moments and correlations, we show that the covariance matrix for <span class="hlt">exchangeable</span> multinomial data has a different form from that usually assumed in the literature, and we analyse data from developmental toxicology studies. The proposed analyses have been implemented in R and are available on CRAN in the CorrBin package.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791380','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4791380"><span id="translatedtitle">Three-Color Chromosome Painting as Seen through the Eyes of mFISH: Another Look at Radiation-<span class="hlt">Induced</span> <span class="hlt">Exchanges</span> and Their Conversion to Whole-Genome Equivalency</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Loucas, Bradford D.; Shuryak, Igor; Cornforth, Michael N.</p> <p>2016-01-01</p> <p>Whole-chromosome painting (WCP) typically involves the fluorescent staining of a small number of chromosomes. Consequently, it is capable of detecting only a fraction of <span class="hlt">exchanges</span> that occur among the full complement of chromosomes in a genome. Mathematical corrections are commonly applied to WCP data in order to extrapolate the frequency of <span class="hlt">exchanges</span> occurring in the entire genome [whole-genome equivalency (WGE)]. However, the reliability of WCP to WGE extrapolations depends on underlying assumptions whose conditions are seldom met in actual experimental situations, in particular the presumed absence of complex <span class="hlt">exchanges</span>. Using multi-fluor fluorescence in situ hybridization (mFISH), we analyzed the induction of simple <span class="hlt">exchanges</span> produced by graded doses of 137Cs gamma rays (0–4 Gy), and also 1.1 GeV 56Fe ions (0–1.5 Gy). In order to represent cytogenetic damage as it would have appeared to the observer following standard three-color WCP, all mFISH information pertaining to <span class="hlt">exchanges</span> that did not specifically involve chromosomes 1, 2, or 4 was ignored. This allowed us to reconstruct dose–responses for three-color apparently simple (AS) <span class="hlt">exchanges</span>. Using extrapolation methods similar to those derived elsewhere, these were expressed in terms of WGE for comparison to mFISH data. Based on AS events, the extrapolated frequencies systematically overestimated those actually observed by mFISH. For gamma rays, these errors were practically independent of dose. When constrained to a relatively narrow range of doses, the WGE corrections applied to both 56Fe and gamma rays predicted genome-equivalent damage with a level of accuracy likely sufficient for most applications. However, the apparent accuracy associated with WCP to WGE corrections is both fortuitous and misleading. This is because (in normal practice) such corrections can only be applied to AS <span class="hlt">exchanges</span>, which are known to include complex aberrations in the form of pseudosimple <span class="hlt">exchanges</span>. When WCP to WGE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27014627','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27014627"><span id="translatedtitle">Three-Color Chromosome Painting as Seen through the Eyes of mFISH: Another Look at Radiation-<span class="hlt">Induced</span> <span class="hlt">Exchanges</span> and Their Conversion to Whole-Genome Equivalency.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loucas, Bradford D; Shuryak, Igor; Cornforth, Michael N</p> <p>2016-01-01</p> <p>Whole-chromosome painting (WCP) typically involves the fluorescent staining of a small number of chromosomes. Consequently, it is capable of detecting only a fraction of <span class="hlt">exchanges</span> that occur among the full complement of chromosomes in a genome. Mathematical corrections are commonly applied to WCP data in order to extrapolate the frequency of <span class="hlt">exchanges</span> occurring in the entire genome [whole-genome equivalency (WGE)]. However, the reliability of WCP to WGE extrapolations depends on underlying assumptions whose conditions are seldom met in actual experimental situations, in particular the presumed absence of complex <span class="hlt">exchanges</span>. Using multi-fluor fluorescence in situ hybridization (mFISH), we analyzed the induction of simple <span class="hlt">exchanges</span> produced by graded doses of (137)Cs gamma rays (0-4 Gy), and also 1.1 GeV (56)Fe ions (0-1.5 Gy). In order to represent cytogenetic damage as it would have appeared to the observer following standard three-color WCP, all mFISH information pertaining to <span class="hlt">exchanges</span> that did not specifically involve chromosomes 1, 2, or 4 was ignored. This allowed us to reconstruct dose-responses for three-color apparently simple (AS) <span class="hlt">exchanges</span>. Using extrapolation methods similar to those derived elsewhere, these were expressed in terms of WGE for comparison to mFISH data. Based on AS events, the extrapolated frequencies systematically overestimated those actually observed by mFISH. For gamma rays, these errors were practically independent of dose. When constrained to a relatively narrow range of doses, the WGE corrections applied to both (56)Fe and gamma rays predicted genome-equivalent damage with a level of accuracy likely sufficient for most applications. However, the apparent accuracy associated with WCP to WGE corrections is both fortuitous and misleading. This is because (in normal practice) such corrections can only be applied to AS <span class="hlt">exchanges</span>, which are known to include complex aberrations in the form of pseudosimple <span class="hlt">exchanges</span>. When WCP to WGE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('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://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/2060/20110012957','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012957"><span id="translatedtitle">Microscale Regenerative Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred</p> <p>2006-01-01</p> <p>The device described herein is designed primarily for use as a regenerative heat <span class="hlt">exchanger</span> in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat <span class="hlt">exchanger</span> (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150015577','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150015577"><span id="translatedtitle">Alert <span class="hlt">Exchange</span> Process Protocol</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Groen, Frank</p> <p>2015-01-01</p> <p>The National Aeronautics and Space Administration of the United States of America (NASA), and the European Space Agency (ESA), and the Japanese Aerospace Exploration Agency (JAXA), acknowledging that NASA, ESA and JAXA have a mutual interest in <span class="hlt">exchanging</span> Alerts and Alert Status Lists to enhance the information base for each system participant while fortifying the general level of cooperation between the policy agreement subscribers, and each Party will <span class="hlt">exchange</span> Alert listings on regular basis and detailed Alert information on a need to know basis to the extent permitted by law.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/GPO-UA-2010-04-26/pdf/GPO-UA-2010-04-26-22.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/GPO-UA-2010-04-26/pdf/GPO-UA-2010-04-26-22.pdf"><span id="translatedtitle">Securities and <span class="hlt">Exchange</span> Commission Semiannual Regulatory Agenda</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-04-26</p> <p>... [Securities and <span class="hlt">Exchange</span> Commission Semiannual Regulatory Agenda ] Part XXIII Securities and <span class="hlt">Exchange</span> Commission Semiannual Regulatory Agenda ] SECURITIES AND <span class="hlt">EXCHANGE</span> COMMISSION (SEC) SECURITIES AND <span class="hlt">EXCHANGE</span> COMMISSION 17 CFR Ch. II Regulatory Flexibility Agenda AGENCY: Securities and <span class="hlt">Exchange</span> Commission. ACTION: Semiannual regulatory...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED387394.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED387394.pdf"><span id="translatedtitle">Currency <span class="hlt">Exchange</span> Rates.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Siler, Carl R.</p> <p></p> <p>This curriculum unit of the Muncie (Indiana) Southside High School is to simulate the dynamics of foreign currency <span class="hlt">exchange</span> rates from the perspectives of: (1) a major U.S. corporation, ABB Power T & D Company, Inc., of Muncie, Indiana, a manufacturer of large power transformers for the domestic and foreign markets; and (2) individual consumers…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5374745','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5374745"><span id="translatedtitle">Estimate <span class="hlt">exchanger</span> vibration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nieh, C.D.; Zengyan, H.</p> <p>1986-04-01</p> <p>Based on the classical beam theory, a simple method for calculating the natural frequency of unequally spanned tubes is presented. The method is suitable for various boundary conditions. Accuracy of the calculations is sufficient for practical applications. This method will help designers and operators estimate the vibration of tubular <span class="hlt">exchangers</span>. In general, there are three reasons why a tube vibrates in cross flow: vortex shedding, fluid elasticity and turbulent buffeting. No matter which is the cause, the basic reason is that the frequency of exciting force is approximately the same as or equal to the natural frequency of the tube. To prevent the heat <span class="hlt">exchanger</span> from vibrating, it is necessary to select correctly the shell-side fluid velocity so that the frequency of exciting force is different from the natural frequency of the tube, or to vary the natural frequency of the heat <span class="hlt">exchanger</span> tube. So precisely determining the natural frequency of the heat <span class="hlt">exchanger</span>, especially its foundational frequency under various supporting conditions, is of significance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/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 provides…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED497931.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED497931.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span> 2006</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2006-01-01</p> <p>Contributors to this issue of the Higher Education <span class="hlt">Exchange</span> debate the issues around knowledge production, discuss the acquisition of deliberative skills for democracy, and examine how higher education prepares, or does not prepare, students for citizenship roles. Articles include: (1) "Foreword" (Deborah Witte); (2) "Knowledge, Judgment and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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://www.osti.gov/scitech/biblio/6467241','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6467241"><span id="translatedtitle">Heat <span class="hlt">exchange</span> enhancement structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cornelison, R.C.; Kreith, F.</p> <p>1980-12-02</p> <p>A passive heat <span class="hlt">exchange</span> enhancement structure which operates by free convection includes a flat mounting portion having a plurality of integral fins bent outwardly from one side edge thereof. The mounting portion is securable around a stovepipe, to a flat surface or the like for transferring heat from the pipe through the fins to the surrounding air by rotation-enhanced free convection.</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://eric.ed.gov/?q=convection&pg=5&id=EJ452044','ERIC'); return false;" href="http://eric.ed.gov/?q=convection&pg=5&id=EJ452044"><span id="translatedtitle">Nature's Heat <span class="hlt">Exchangers</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Barnes, George</p> <p>1991-01-01</p> <p>Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat <span class="hlt">exchange</span> in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5758003','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5758003"><span id="translatedtitle">Chimney heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whiteley, I.C.</p> <p>1981-09-01</p> <p>A heat <span class="hlt">exchanger</span> for installation on the top of a chimney of a building includes a housing having a lower end receiving the top of the chimney and an upper end with openings permitting the escape of effluent from the chimney and a heat <span class="hlt">exchanger</span> assembly disposed in the housing including a central chamber and a spirally arranged duct network defining an effluent spiral path between the top of the chimney and the central chamber and a fresh air spiral path between an inlet disposed at the lower end of the housing and the central chamber, the effluent and fresh air spiral paths being in heat <span class="hlt">exchange</span> relationship such that air passing through the fresh air spiral path is heated by hot effluent gases passing upward through the chimney and the effluent spiral path for use in heating the building. A pollution trap can be disposed in the central chamber of the heat <span class="hlt">exchanger</span> assembly for removing pollutants from the effluent, the pollution trap including a rotating cage carrying pumice stones for absorbing pollutants from the effluent with the surface of the pumice gradually ground off to reveal fresh stone as the cage rotates.</p> </li> </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://eric.ed.gov/?q=south+AND+china&pg=7&id=EJ346259','ERIC'); return false;" href="http://eric.ed.gov/?q=south+AND+china&pg=7&id=EJ346259"><span id="translatedtitle">Visiting Scholar <span class="hlt">Exchange</span> Reports.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rubin, Kyna, Ed.</p> <p>1986-01-01</p> <p>Provides reports of four United States scholars who visited China as part of the Visiting Scholar <span class="hlt">Exchange</span> Program. The titles of the reports are (1) "China Journey: A Political Scientist's Look at Yan'an," (2) "The Social Consequences of Land Reclamation in Chinese Coastal Ecosystems," (3) "Anthropology Lectures in South China," and (4) "The Use…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED510123.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED510123.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2009-01-01</p> <p>This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education <span class="hlt">Exchange</span> (HEX). She reiterates Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological conundrum of "knowledge produced…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED539321.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED539321.pdf"><span id="translatedtitle">Higher Education <span class="hlt">Exchange</span>, 2009</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, David W., Ed.; Witte, Deborah, Ed.</p> <p>2009-01-01</p> <p>This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education <span class="hlt">Exchange</span> (HEX). She reiterates Kettering's president David Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005EPJB...45..155M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005EPJB...45..155M"><span id="translatedtitle">New Trends in Magnetic <span class="hlt">Exchange</span> Bias</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois</p> <p>2005-05-01</p> <p>The study of layered magnetic structures is one of the hottest topics in magnetism due to the growing attraction of applications in magnetic sensors and magnetic storage media, such as random access memory. For almost half a century, new discoveries have driven researchers to re-investigate magnetism in thin film structures. Phenomena such as giant magnetoresistance, tunneling magnetoresistance, <span class="hlt">exchange</span> bias and interlayer <span class="hlt">exchange</span> coupling led to new ideas to construct devices, based not only on semiconductors but on a variety of magnetic materials Upon cooling fine cobalt particles in a magnetic field through the Néel temperature of their outer antiferromagnetic oxide layer, Meiklejohn and Bean discovered <span class="hlt">exchange</span> bias in 1956. The <span class="hlt">exchange</span> bias effect through which an antiferromagnetic AF layer can cause an adjacent ferromagnetic F layer to develop a preferred direction of magnetization, is widely used in magnetoelectronics technology to pin the magnetization of a device reference layer in a desired direction. However, the origin and effects due to <span class="hlt">exchange</span> interaction across the interface between antiferromagneic and ferromagnetic layers are still debated after about fifty years of research, due to the extreme difficulty associated with the determination of the magnetic interfacial structure in F/AF bilayers. Indeed, in an AF/F bilayer system, the AF layer acts as “the invisible man” during conventional magnetic measurements and the presence of the <span class="hlt">exchange</span> coupling is evidenced indirectly through the unusual behavior of the adjacent F layer. Basically, the coercive field of the F layer increases in contact with the AF and, in some cases, its hysteresis loop is shifted by an amount called <span class="hlt">exchange</span> bias field. Thus, AF/F <span class="hlt">exchange</span> coupling generates a new source of anisotropy in the F layer. This <span class="hlt">induced</span> anisotropy strongly depends on basic features such as the magnetocrystalline anisotropy, crystallographic and spin structures, defects, domain patterns etc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/191747','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/191747"><span id="translatedtitle">Composite ion <span class="hlt">exchange</span> materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Amarasinghe, S.; Zook, L.; Leddy, J.</p> <p>1994-12-31</p> <p>Composite ion <span class="hlt">exchange</span> materials can be formed by sorbing ion <span class="hlt">exchange</span> polymers on inert, high surface area substrates. In general, the flux of ions and molecules through these composites, as measured electrochemically, increases as the ratio of the surface area of the substrate increases relative to the volume of the ion <span class="hlt">exchanger</span>. This suggests that fields and gradients established at the interface between the ion <span class="hlt">exchanger</span> and substrate are important in determining the transport characteristics of the composites. Here, the authors will focus on composites formed with a cation <span class="hlt">exchange</span> polymer, Nafion, and two different types of microbeads: polystyrene microspheres and polystyrene coated magnetic microbeads. For the polystyrene microbeads, scanning electron micrographs suggest the beads cluster in a self-similar manner, independent of the bead diameter. Flux of Ru(NH3)63+ through the composites was studied as a function of bead fraction, bead radii, and fixed surface area with mixed bead sizes. Flux was well modeled by surface diffusion along a fractal interface. Magnetic composites were formed with columns of magnetic microbeads normal to the electrode surface. Flux of Ru(NH3)63+ through these composites increased exponentially with bead fraction. For electrolyses, the difference in the molar magnetic susceptibility of the products and reactants, Dcm, tends to be non-zero. For seven redox reactions, the ratio of the flux through the magnetic composites to the flux through a Nafion film increases monotonically with {vert_bar}Dcm{vert_bar}, with enhancements as large as thirty-fold. For reversible species, the electrolysis potential through the magnetic composites is 35 mV positive of that for the Nafion films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001428','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001428"><span id="translatedtitle">Counterflow Regolith Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zubrin, Robert; Jonscher, Peter</p> <p>2013-01-01</p> <p>A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat <span class="hlt">exchanger</span> (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat <span class="hlt">exchanger</span> with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat <span class="hlt">exchanger</span> close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat <span class="hlt">exchange</span> to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat <span class="hlt">exchanger</span> itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6562578','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6562578"><span id="translatedtitle">A corrosive resistant heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Richlen, S.L.</p> <p>1987-08-10</p> <p>A corrosive and erosive resistant heat <span class="hlt">exchanger</span> which recovers heat from a contaminated heat stream. The heat <span class="hlt">exchanger</span> utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat <span class="hlt">exchanger</span> surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat <span class="hlt">exchanger</span> wall. Heat from the heat stream is transferred by radiation to the heat <span class="hlt">exchanger</span> wall. Heat is removed from the outer heat <span class="hlt">exchanger</span> wall by a heat recovery medium. 3 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27557685','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27557685"><span id="translatedtitle">Generation and Analysis of Transposon Ac/Ds-<span class="hlt">Induced</span> Chromosomal Rearrangements in Rice Plants.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xuan, Yuan Hu; Peterson, Thomas; Han, Chang-Deok</p> <p>2016-01-01</p> <p>Closely-located transposable elements (TEs) have been known to <span class="hlt">induce</span> chromosomal breakage and rearrangements via alternative transposition. To study genome rearrangements in rice, an Ac/Ds system has been employed. This system comprises an immobile Ac element expressed under the control of CaMV 35S promoter, and a modified Ds element. A starter line carried Ac and a single copy of Ds at the OsRLG5 (Oryza sativa receptor-like gene 5). To enhance the transpositional activity, seed-derived calli were cultured and regenerated into plants. Among 270 lines regenerated from the starter, one line was selected that contained a pair of inversely-oriented Ds elements at the OsRLG5 (Oryza sativa receptor-like gene 5). The selected line was again subjected to tissue culture to obtain a regenerant population. Among 300 regenerated plants, 107 (36 %) contained chromosomal rearrangements including deletions, duplications, and inversions of various sizes. From 34 plants, transposition mechanisms leading to such genomic rearrangements were analyzed. The rearrangements were <span class="hlt">induced</span> by sister <span class="hlt">chromatid</span> transposition (SCT), homologous recombination (HR), and single <span class="hlt">chromatid</span> transposition (SLCT). Among them, 22 events (65 %) were found to be transmitted to the next generation. These results demonstrate a great potential of tissue culture regeneration and the Ac/Ds system in understanding alternative transposition mechanisms and in developing chromosome engineering in plants. PMID:27557685</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/1521837','PUBMED'); return false;" href="http://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="http://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. PMID:1521837</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://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.ncbi.nlm.nih.gov/pubmed/26695050','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26695050"><span id="translatedtitle">Lipid <span class="hlt">Exchange</span> by Ultracentrifugation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Drachmann, Nikolaj Düring; Olesen, Claus</p> <p>2016-01-01</p> <p>Lipids play an important role in maintaining P-type ATPase structure and function, and often they are crucial for ATPase activity. When the P-type ATPases are in the membrane, they are surrounded by a mix of different lipid species with varying aliphatic chain lengths and saturation, and the complex interplay between the lipids and the P-type ATPases are still not well understood. We here describe a robust method to <span class="hlt">exchange</span> the majority of the lipids surrounding the ATPase after solubilisation and/or purification with a target lipid of interest. The method is based on an ultracentrifugation step, where the protein sample is spun through a dense buffer containing large excess of the target lipid, which results in an approximately 80-85 % lipid <span class="hlt">exchange</span>. The method is a very gently technique that maintains protein folding during the process, hence allowing further characterization of the protein in the presence of a target lipid of interest. PMID:26695050</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040173044&hterms=C57BL%2f6&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DC57BL%252F6','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040173044&hterms=C57BL%2f6&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DC57BL%252F6"><span id="translatedtitle">Radiation-<span class="hlt">induced</span> chromosomal instability in BALB/c and C57BL/6 mice: the difference is as clear as black and white</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ponnaiya, B.; Cornforth, M. N.; Ullrich, R. L.</p> <p>1997-01-01</p> <p>Genomic instability has been proposed to be the earliest step in radiation-<span class="hlt">induced</span> tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-<span class="hlt">induced</span> instability. BALB/c white mice are considerably more sensitive to radiation-<span class="hlt">induced</span> mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the "delayed" appearance of chromosomal aberrations after exposure to 137Cs gamma radiation, as a measure of radiation-<span class="hlt">induced</span> genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of <span class="hlt">chromatid</span>-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of <span class="hlt">chromatid</span>-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-<span class="hlt">induced</span> instability in the process of tumorigenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('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('http://www.osti.gov/scitech/servlets/purl/913578','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/913578"><span id="translatedtitle">Thermoelectric heat <span class="hlt">exchange</span> element</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Callas, James J.; Taher, Mahmoud A.</p> <p>2007-08-14</p> <p>A thermoelectric heat <span class="hlt">exchange</span> module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1174441','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1174441"><span id="translatedtitle">Heat <span class="hlt">exchange</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Degtiarenko, Pavel V.</p> <p>2003-08-12</p> <p>A heat <span class="hlt">exchange</span> apparatus comprising a coolant conduit or heat sink having attached to its surface a first radial array of spaced-apart parallel plate fins or needles and a second radial array of spaced-apart parallel plate fins or needles thermally coupled to a body to be cooled and meshed with, but not contacting the first radial array of spaced-apart parallel plate fins or needles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991EOSTr..72..251.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991EOSTr..72..251."><span id="translatedtitle">Soviets seek scientific <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></p> <p></p> <p>GEOS-A, associated with the Soviet Union's Institute of Earth Physics, is seeking to promote <span class="hlt">exchange</span> between Soviet and Western geophysicists. GEOS-A is a nonprofit, private organization formed by specialists from the U.S.S.R. Academy of Scientists.GEOS-A aims to promote the transfer of academic research results to industry and education. It also seeks to stimulate international scientific <span class="hlt">exchange</span> and to support independent nongovernmental programs and expertise in geophysics and ecology. The organization would like to cooperate with Western universities in <span class="hlt">exchanging</span> students and young scientists and in building scientific relationships between the two countries. This would include inviting students and young specialists for collaborative scientific research, consultations, language practice, and graduate study in any institute of the U.S.S.R. Academy of Sciences. Participants would live in rented private apartments in downtown Moscow for approximately one week to several months. All living expenses would be covered at a rate higher than the academy's standard one (unfortunately travel to and from the Soviet Union cannot be covered).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2987866','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2987866"><span id="translatedtitle">The <span class="hlt">exchangeability</span> of shape</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2010-01-01</p> <p>Background Landmark based geometric morphometrics (GM) allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data <span class="hlt">exchange</span>, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species. Results We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of <span class="hlt">exchangeability</span> of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species. Conclusions To preserve both <span class="hlt">exchangeability</span> of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes. PMID:20964872</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=132540&keyword=commodities&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=75016103&CFTOKEN=73429545','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=132540&keyword=commodities&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=75016103&CFTOKEN=73429545"><span id="translatedtitle">AGRICULTURAL <span class="hlt">EXCHANGE</span> RATE DATA SHEET</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>The ERS data set contains annual and monthly data for <span class="hlt">exchange</span> rates important to U.S. agriculture. It includes both nominal and real <span class="hlt">exchange</span> rates for 80 countries (plus the European Union) as well as real trade-weighted <span class="hlt">exchange</span> rate indexes for many commodities and aggregatio...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1002787','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1002787"><span id="translatedtitle">Thrombotic thrombocytopenic purpura treated with plasma <span class="hlt">exchange</span> or <span class="hlt">exchange</span> transfusions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shepard, K. V.; Fishleder, A.; Lucas, F. V.; Goormastic, M.; Bukowski, R. M.</p> <p>1991-01-01</p> <p>Of 40 patients with thrombotic thrombocytopenic purpura, 17 were treated with plasma <span class="hlt">exchange</span>, 15 with <span class="hlt">exchange</span> transfusions, and 6 with both types of therapy. One patient died before being treated and another patient was seen but not treated. Plasma <span class="hlt">exchange</span> was performed daily for a mean of seven <span class="hlt">exchanges</span> per patient. The replacement fluid during plasma <span class="hlt">exchange</span> was fresh frozen plasma in all cases. The complete response rates for each type of treatment were as follows: 88% for plasma <span class="hlt">exchange</span> (15 patients), 47% for <span class="hlt">exchange</span> transfusions (7 patients), and 67% for <span class="hlt">exchange</span> transfusions and plasma <span class="hlt">exchange</span> (4 patients). Clinical and laboratory factors were examined for any statistically significant association with therapy response. Treatment with plasma <span class="hlt">exchange</span> was statistically the initial factor most strongly associated with prognosis. Paresis, paresthesias, seizures, mental status change, and coma showed no association with response to treatment. Some of the laboratory factors that did not show significant association with treatment response were the initial creatinine, hemoglobin, platelet count, lactate dehydrogenase, and total bilirubin. This study supports the hypothesis that plasma <span class="hlt">exchange</span> has significantly improved the prognosis of patients with thrombotic thrombocytopenic purpura. These patients should be treated aggressively regardless of the severity of their symptoms. 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