首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   748篇
  免费   41篇
  国内免费   2篇
  2023年   9篇
  2022年   18篇
  2021年   61篇
  2020年   21篇
  2019年   27篇
  2018年   25篇
  2017年   24篇
  2016年   49篇
  2015年   34篇
  2014年   49篇
  2013年   65篇
  2012年   55篇
  2011年   48篇
  2010年   25篇
  2009年   22篇
  2008年   34篇
  2007年   27篇
  2006年   27篇
  2005年   31篇
  2004年   26篇
  2003年   18篇
  2002年   22篇
  2001年   4篇
  2000年   9篇
  1999年   4篇
  1997年   2篇
  1995年   2篇
  1994年   3篇
  1993年   4篇
  1991年   2篇
  1989年   5篇
  1985年   1篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   2篇
  1971年   1篇
  1970年   2篇
  1968年   2篇
  1967年   1篇
  1966年   2篇
  1964年   1篇
排序方式: 共有791条查询结果,搜索用时 234 毫秒
731.
The present investigation deals with the determination of various serum enzymes known to be elevated during myocardial infarction (MI) and estimation of selected metals like Cu, Cr, Co, Fe, Pb, and Mg by flame atomic absorption spectrophotometry. The data obtained thereby were processed for the determination of correlation coefficient matrix among the cardiac enzymes and the serum metals. The study evidenced the accumulation of Pb during MI and reduction in the level of Fe. A significant negative correlation was observed between Cu and creatine kinase-MB. The data were also segregated into various groups to study the influence of age and gender on the levels of selected parameters. In both the genders, the age of the patients was found to be correlated significantly with various cardiac enzymes. In case of male patients, the most significant correlation was observed between age and blood sugar at random. The other significant correlations among the male patients included Cr–CPK, Cr–creatine kinase-MB, Fe–age, and others. In female patients, the pairs of studied parameters that exhibited significant correlations included age–lactic dehydrogenase, creatine phosphokinase isoenzyme–aspartate aminotransferase, lactic dehydrogenase–creatine phosphokinase isoenzymes, Pb-Fe, and Cu-Co in addition to others.  相似文献   
732.
A new genus ofEncyrtidae is erected for one new species described from females and males taken in Pakistan.  相似文献   
733.
734.
We have previously shown that the microfilarial (mf) stage of Brugia malayi can inhibit the mammalian target of rapamycin (mTOR; a conserved serine/threonine kinase critical for immune regulation and cellular growth) in human dendritic cells (DC) and we have proposed that this mTOR inhibition is associated with the DC dysfunction seen in filarial infections. Extracellular vesicles (EVs) contain many proteins and nucleic acids including microRNAs (miRNAs) that might affect a variety of intracellular pathways. Thus, EVs secreted from mf may elucidate the mechanism by which the parasite is able to modulate the host immune response during infection. EVs, purified from mf of Brugia malayi and confirmed by size through nanoparticle tracking analysis, were assessed by miRNA microarrays (accession number GSE157226) and shown to be enriched (>2-fold, p-value<0.05, FDR = 0.05) for miR100, miR71, miR34, and miR7. The microarray analysis compared mf-derived EVs and mf supernatant. After confirming their presence in EVs using qPCR for these miRNA targets, web-based target predictions (using MIRPathv3, TarBAse and MicroT-CD) predicted that miR100 targeted mTOR and its downstream regulatory protein 4E-BP1. Our previous data with live parasites demonstrated that mf downregulate the phosphorylation of mTOR and its downstream effectors. Additionally, our proteomic analysis of the mf-derived EVs revealed the presence of proteins commonly found in these vesicles (data are available via ProteomeXchange with identifier PXD021844). We confirmed internalization of mf-derived EVs by human DCs and monocytes using confocal microscopy and flow cytometry, and further demonstrated through flow cytometry, that mf-derived EVs downregulate the phosphorylation of mTOR in human monocytes (THP-1 cells) to the same degree that rapamycin (a known mTOR inhibitor) does. Our data collectively suggest that mf release EVs that interact with host cells, such as DC, to modulate host responses.  相似文献   
735.
736.
737.
Iqbal  Reema  Khan  Tariq 《Biotechnology letters》2022,44(8):933-950
Biotechnology Letters - Melatonin is a natural indolamine that regulates many physiological functions in plants. The most prominent role of melatonin in plants has been its ability to work as an...  相似文献   
738.
There is much public interest in the use of fungal biological control agents as alternatives to chemical pesticides. However, there are some concerns as to whether the metabolites produced by these fungi pose a risk to humans and the environment. Destruxins are the main metabolites produced by the insect pathogenic fungus Metarhizium anisopliae (Metsch.) Sorok. The production of these compounds in two different insect hosts and their subsequent fate in the soil were assessed as a case study. Destruxin profiling revealed that the amount and type of destruxin produced was dependant upon the fungal strain and insect host and that these compounds decomposed shortly after host death. Destruxin decomposition was presumably due to the activity of hydrolytic enzymes in the cadavers and appeared to be independent of host or soil type and biota. Temperature strongly influenced destruxin decomposition. Our studies are the first to show that the destruxins are essentially restricted to the host and pathogen and are unlikely to contaminate the environment or enter the food chain.  相似文献   
739.
It remains unclear how specific mechanical signals generated by applied dynamic compression (DC) regulate chondrocyte biosynthetic activity. It has previously been suggested that DC-induced interstitial fluid flow positively impacts cartilage-specific matrix production. Modifying fluid flow within dynamically compressed hydrogels therefore represents a promising approach to controlling chondrocyte behavior, which could potentially be achieved by changing the construct architecture. The objective of this study was to first determine the influence of construct architecture on the mechanical environment within dynamically compressed agarose hydrogels using finite element (FE) modeling and to then investigate how chondrocytes would respond to this altered environment. To modify construct architecture, an array of channels was introduced into the hydrogels. Increased magnitudes of fluid flow were predicted in the periphery of dynamically compressed solid hydrogels and also around the channels in the dynamically compressed channeled hydrogels. DC was found to significantly increase sGAG synthesis in solid constructs, which could be attributed at least in part to an increase in DNA. DC was also found to preferentially increase collagen accumulation in regions of solid and channeled constructs where FE modeling predicted higher levels of fluid flow, suggesting that this stimulus is important for promoting collagen production by chondrocytes embedded in agarose gels. In conclusion, this study demonstrates how the architecture of cell-seeded scaffolds or hydrogels can be modified to alter the spatial levels of biophysical cues throughout the construct, leading to greater collagen accumulation throughout the engineered tissue rather than preferentially in the construct periphery. This system also provides a novel approach to investigate how chondrocytes respond to altered levels of biophysical stimulation.  相似文献   
740.
Biological Trace Element Research - The objective of this study was to investigate the cadmium (Cd) profile in seminal plasma of male dromedary camel with impotentia generandi (post-coital...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号