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排序方式: 共有182条查询结果,搜索用时 15 毫秒
21.
Saadat M Bahaoddini A Nazemi S 《Biochemical and biophysical research communications》2004,313(3):568-569
In order to show the alteration of blood pressure in subjects chronically exposed to natural gas containing sulfur compounds, the present study was done. The blood pressure of 94 (43 males, 51 females) of healthy individuals living in the polluted area of Masjid-i-Sulaiman (Khozestan province, southwest of Iran) was measured. The non-parametric Sign test was applied in order to detect differences between the study subjects and the normal mean values according to the sex and age of subjects. Statistical analysis showed that the systolic blood pressure significantly decreased (Z=-2.74; P=0.0031) while the diastolic blood pressure (Z=+2.11; P=0.0174) and heart rate (Z=+3.62; P<0.001) significantly increased in individuals living in the contaminated areas compared with those of normal mean values. The systolic and diastolic blood pressure decreased and increased, respectively, in individuals chronically exposed to natural sour gas containing sulfur compounds. 相似文献
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在害虫治理中,在消费或贮藏粮食加工产品的建筑设施或场所进行害虫防治需要将杀虫剂施用在各种基质表面上.为了测定不同基质表面上杀虫剂的药效,将四纹豆象Callosobruchus maculatus(F.)成虫接触田间推荐剂量的阿维菌素、溴氰菊酯和毒死蜱.结果表明:施用在玻璃、瓷砖、塑料和纸盘表面上,阿维菌素对四纹豆象成虫的致死率分别为63.33%,22.41%,12.9%和11.9%,而溴氰菊酯在这4种基质表面上对四纹豆象成虫的致死率分别为55%,44.2%,41.3%和37.4%.在所有基质表面上接触毒死蜱,四纹豆象成虫的死亡率均为100%.对数据进行的Probit分析表明,毒死蜱制剂在玻璃、瓷砖、塑料和纸盘上对四纹豆象成虫的LC50值分别为8.66,13.6,29 16和56.5 μg/mL,阿维菌素制剂的相应数值分别为119.4,446.2,774.2和836.4μg/mL,溴氰菊酯制剂的相应数值分别为1008,1131,1210和1336 μg/mL.据此推断,毒死蜱对四纹豆象的毒性最强,且在玻璃、瓷砖、塑料和纸盘表面上的毒性依次降低. 相似文献
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Piro JR Benjamin DI Duerr JM Pi Y Gonzales C Wood KM Schwartz JW Nomura DK Samad TA 《Cell reports》2012,1(6):617-623
Highlights? Monoacylglycerol lipase (MAGL) is a major contributor to brain arachidonic acid pools ? MAGL mutation decreases neuroinflammation and amyloid β in Alzheimer's disease mouse ? MAGL blockade recapitulates brain prostaglandin and cytokine-lowering effects ? MAGL inhibitors may be a next-generation strategy for combating Alzheimer's disease 相似文献
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Shah C Yang G Lee I Bielawski J Hannun YA Samad F 《The Journal of biological chemistry》2008,283(20):13538-13548
Obesity increases the risk for metabolic and cardiovascular disease, and adipose tissue plays a central role in this process. Ceramide, the key intermediate of sphingolipid metabolism, also contributes to obesity-related disorders. We show that a high fat diet increased ceramide levels in the adipose tissues and plasma in C57BL/6J mice via a mechanism that involves an increase in gene expression of enzymes mediating ceramide generation through the de novo pathway (e.g. serine palmitoyltransferase) and via the hydrolysis of sphingomyelin (acid sphingomyelinase and neutral sphingomyelinase). Although the induction of total ceramide in response to the high fat diet was modest, dramatic increases were observed for C16, C18, and C18:1 ceramides. Next, we investigated the relationship of ceramide to plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of plasminogen activation and another key player in obesity. PAI-1 is consistently elevated in obesity and thought to contribute to increased artherothrombotic events and more recently to obesity-mediated insulin resistance. Interestingly, the changes in ceramide were attenuated in mice lacking PAI-1. Mechanistically, mice lacking PAI-1 were protected from diet-induced increase in serine palmitoyltransferase, acid sphingomyelinase, and neutral sphingomyelinase mRNA, providing a mechanistic link for decreased ceramide in PAI-1-/- mice. The decreases in plasma free fatty acids and adipose tumor necrosis factor-alpha in PAI-1-/- mice may have additionally contributed indirectly to improvements in ceramide profile in these mice. This study has identified a novel link between sphingolipid metabolism and PAI-1 and also suggests that ceramide may be an intermediary molecule linking elevated PAI-1 to insulin resistance. 相似文献
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Stéphane Compant Marine C. Cambon Corinne Vacher Birgit Mitter Abdul Samad Angela Sessitsch 《Environmental microbiology》2021,23(4):1812-1829
The plant endosphere is colonized by complex microbial communities and microorganisms, which colonize the plant interior at least part of their lifetime and are termed endophytes. Their functions range from mutualism to pathogenicity. All plant organs and tissues are generally colonized by bacterial endophytes and their diversity and composition depend on the plant, the plant organ and its physiological conditions, the plant growth stage as well as on the environment. Plant-associated microorganisms, and in particular endophytes, have lately received high attention, because of the increasing awareness of the importance of host-associated microbiota for the functioning and performance of their host. Some endophyte functions are known from mostly lab assays, genome prediction and few metagenome analyses; however, we have limited understanding on in planta activities, particularly considering the diversity of micro-environments and the dynamics of conditions. In our review, we present recent findings on endosphere environments, their physiological conditions and endophyte colonization. Furthermore, we discuss microbial functions, the interaction between endophytes and plants as well as methodological limitations of endophyte research. We also provide an outlook on needs of future research to improve our understanding on the role of microbiota colonizing the endosphere on plant traits and ecosystem functioning. 相似文献
30.
The ;malic' enzyme (EC 1.1.1.40) has been purified (300-fold) from wheat germ and its abilities to catalyse the decarboxylation and the hydrogenation of oxaloacetic acid and oxaloacetate esters was studied. The free 1-carboxyl group is essential for the interaction of oxaloacetates and substituted oxaloacetates with the enzyme via cations. The free 4-carboxyl group is required for the decarboxylation but is not indispensable for the hydrogenation. At high concentrations, cations inhibit the enzymic hydrogenation of oxaloacetic acid but not that of 4-ethyl oxaloacetate. A plausible inhibitory mechanism is proposed. 相似文献