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P. David Josephy Jody J. Weadge Joseph Meissner Filomena Ng 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2008,654(1):64-68
Zero-valent nickel compounds are organometallic chemicals that are used in synthetic applications and may also occur as intermediates in nickel-catalyzed hydrogenation reactions used in food processing. Few studies have been performed on their possible genotoxic actions. We have tested two commercially available examples of this class of compounds. Solubility and stability were examined. Mutagenicity testing did not confirm a previous report that bis(1,5-cyclooctadiene)nickel is positive in the Ames assay. No stimulation of lipid peroxidation was observed in studies of bovine erythrocytes exposed in vitro. Our results do not indicate that zero-valent nickel compounds have genotoxic effects. 相似文献
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Microalgae composition, abundance, diversity and biomass of the Qua Iboe Estuary mangrove swamp were studied. The results
revealed the rich assemblage of the brackish ecosystem. Six major taxanomic classes were encountered. These were the Bacillariophyceae,
Cyanophyceae, Chlorophyceae, Chrysophyceae, Euglenophyceae and Phaeophyceae. Their composition, abundance and diversity exhibits
strong seasonal variation. Variations between pelagic and sedimentary habitats were also noticed. The diatoms (Bacillariophyceae)
dominated the habitats. Actinoptychus undalatus, Navicula radiosa and Amphora ovalis co-dominated the pelagic water column; while the epipellic (intertidal) and benthic (subtidal) sediments were co-dominated
by A. ovalis and Actinoptychus undulatus. Analyses of the Shannon’s index of general diversity (H1), McArthur-Terborgh species equitability index (E) and Simpson’s index of dominance (D) of the microalgae communities revealed
that A. ovalis with a mean H
1
-value of 0.25, E-value of 0.08 and D-value of 0.05 was the most prevalent genus in the mangrove ecosystem despite its uneven distribution. The densities of the
microalgae communities corresponded with their biomass statuses and were seriously impacted by oil spillage. This forms the
basis of concern because the estuary is associated with a high probability of major oil pollution with serious consequences
for ecological stability and fisheries. 相似文献
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mGluR long‐term depression regulates GluA2 association with COPII vesicles and exit from the endoplasmic reticulum 下载免费PDF全文
mGluR long‐term depression (mGluR‐LTD) is a form of synaptic plasticity induced at excitatory synapses by metabotropic glutamate receptors (mGluRs). mGluR‐LTD reduces synaptic strength and is relevant to learning and memory, autism, and sensitization to cocaine; however, the mechanism is not known. Here we show that activation of Group I mGluRs in medium spiny neurons induces trafficking of GluA2 from the endoplasmic reticulum (ER) to the synapse by enhancing GluA2 binding to essential COPII vesicle proteins, Sec23 and Sec13. GluA2 exit from the ER further depends on IP3 and Ryanodine receptor‐controlled Ca2+ release as well as active translation. Synaptic insertion of GluA2 is coupled to removal of high‐conducting Ca2+‐permeable AMPA receptors from synapses, resulting in synaptic depression. This work demonstrates a novel mechanism in which mGluR signals release AMPA receptors rapidly from the ER and couple ER release to GluA2 synaptic insertion and GluA1 removal. 相似文献
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