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   2174篇
  免费   126篇
  2300篇
  2022年   21篇
  2021年   59篇
  2020年   19篇
  2019年   33篇
  2018年   40篇
  2017年   42篇
  2016年   57篇
  2015年   76篇
  2014年   118篇
  2013年   113篇
  2012年   127篇
  2011年   132篇
  2010年   102篇
  2009年   76篇
  2008年   99篇
  2007年   109篇
  2006年   82篇
  2005年   84篇
  2004年   51篇
  2003年   53篇
  2002年   54篇
  2001年   51篇
  2000年   40篇
  1999年   24篇
  1997年   16篇
  1996年   15篇
  1993年   14篇
  1992年   16篇
  1991年   29篇
  1990年   27篇
  1989年   20篇
  1988年   23篇
  1987年   35篇
  1986年   34篇
  1985年   26篇
  1984年   27篇
  1983年   21篇
  1982年   16篇
  1981年   21篇
  1980年   14篇
  1979年   27篇
  1977年   20篇
  1976年   18篇
  1975年   20篇
  1973年   19篇
  1972年   27篇
  1971年   20篇
  1970年   14篇
  1969年   15篇
  1967年   16篇
排序方式: 共有2300条查询结果,搜索用时 15 毫秒
71.
72.
Abdominal aortic aneurysms (AAA) are progressive dilatations of infra-renal aorta causing structural weakening rendering the aorta prone to rupture. AAA can be potentially stabilized by inhibiting inflammatory enzymes such as matrix metalloproteinases (MMP); however, active regression of AAA is not possible without new elastic fiber regeneration. Here we report the elastogenic benefit of direct delivery of polyphenols such as pentagalloyl glucose (PGG), epigallocatechin gallate (EGCG), and catechin, to smooth muscle cells obtained either from healthy or from aneurysmal rat aorta. Addition of 10 μg/ml PGG and ECGC induce elastin synthesis, organization, and crosslinking while catechin does not. Our results indicate that polyphenols bind to monomeric tropoelastin and enhance coacervation, aid in crosslinking of elastin by increasing lysyl oxidase (LOX) synthesis, and by blocking MMP-2 activity. Thus, polyphenol treatments leads to increased mature elastin fibers synthesis without increasing the production of intracellular tropoelastin.  相似文献   
73.
74.
75.
Nutrient dynamics in storage organs is a complex developmental process that requires coordinated interactions of environmental, biochemical, and genetic factors. Although sink organ developmental events have been identified, understanding of translational and post‐translational regulation of reserve synthesis, accumulation, and utilization in legumes is limited. To understand nutrient dynamics during embryonic and cotyledonary photoheterotrophic transition to mature and germinating autotrophic seeds, an integrated proteomics and phosphoproteomics study in six sequential seed developmental stages in chickpea is performed. MS/MS analyses identify 109 unique nutrient‐associated proteins (NAPs) involved in metabolism, storage and biogenesis, and protein turnover. Differences and similarities in 60 nutrient‐associated phosphoproteins (NAPPs) containing 93 phosphosites are compared with NAPs. Data reveal accumulation of carbon–nitrogen metabolic and photosynthetic proteoforms during seed filling. Furthermore, enrichment of storage proteoforms and protease inhibitors is associated with cell expansion and seed maturation. Finally, combined proteoforms network analysis identifies three significant modules, centered around malate dehydrogenase, HSP70, triose phosphate isomerase, and vicilin. Novel clues suggest that ubiquitin–proteasome pathway regulates nutrient reallocation. Second, increased abundance of NAPs/NAPPs related to oxidative and serine/threonine signaling indicates direct interface between redox sensing and signaling during seed development. Taken together, nutrient signals act as metabolic and differentiation determinant governing storage organ reprogramming.  相似文献   
76.
Pathogen‐/microbe‐associated molecular patterns (PAMPs/MAMPs) initiate complex defense responses by reorganizing the biomolecular dynamics of the host cellular machinery. The extracellular matrix (ECM) acts as a physical scaffold that prevents recognition and entry of phytopathogens, while guard cells perceive and integrate signals metabolically. Although chitosan is a known MAMP implicated in plant defense, the precise mechanism of chitosan‐triggered immunity (CTI) remains unknown. Here, we show how chitosan imparts immunity against fungal disease. Morpho‐histological examination revealed stomatal closure accompanied by reductions in stomatal conductance and transpiration rate as early responses in chitosan‐treated seedlings upon vascular fusariosis. Electron microscopy and Raman spectroscopy showed ECM fortification leading to oligosaccharide signaling, as documented by increased galactose, pectin and associated secondary metabolites. Multiomics approach using quantitative ECM proteomics and metabolomics identified 325 chitosan‐triggered immune‐responsive proteins (CTIRPs), notably novel ECM structural proteins, LYM2 and receptor‐like kinases, and 65 chitosan‐triggered immune‐responsive metabolites (CTIRMs), including sugars, sugar alcohols, fatty alcohols, organic and amino acids. Identified proteins and metabolites are linked to reactive oxygen species (ROS) production, stomatal movement, root nodule development and root architecture coupled with oligosaccharide signaling that leads to Fusarium resistance. The cumulative data demonstrate that ROS, NO and eATP govern CTI, in addition to induction of PR proteins, CAZymes and PAL activities, besides accumulation of phenolic compounds downstream of CTI. The immune‐related correlation network identified functional hubs in the CTI pathway. Altogether, these shifts led to the discovery of chitosan‐responsive networks that cause significant ECM and guard cell remodeling, and translate ECM cues into cell fate decisions during fusariosis.  相似文献   
77.
Plant Molecular Biology - Cross-talk between light and ABA signaling is mediated by physical interaction between HY5 and ABI5 Arabidopsis. Plants undergo numerous transitions during their...  相似文献   
78.
Molecular and Cellular Biochemistry - Oxidative stress has been known to be the underlying cause in many instances of cancer development. The new aspect of cancer genesis that has caught the...  相似文献   
79.
Plant Molecular Biology Reporter - Polyploidization plays an important role in the genesis of cultivated wheat (hexaploid and tetraploid) from its diploid progenitors. Thus, evolution during...  相似文献   
80.
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