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   937篇
  免费   102篇
  国内免费   1篇
  1040篇
  2022年   7篇
  2021年   17篇
  2019年   7篇
  2018年   10篇
  2016年   19篇
  2015年   45篇
  2014年   42篇
  2013年   42篇
  2012年   77篇
  2011年   84篇
  2010年   57篇
  2009年   37篇
  2008年   23篇
  2007年   24篇
  2006年   19篇
  2005年   24篇
  2004年   31篇
  2003年   16篇
  2002年   21篇
  2001年   11篇
  2000年   24篇
  1999年   18篇
  1998年   15篇
  1997年   9篇
  1996年   15篇
  1995年   9篇
  1993年   13篇
  1992年   13篇
  1991年   23篇
  1990年   14篇
  1989年   11篇
  1988年   13篇
  1987年   10篇
  1986年   10篇
  1985年   12篇
  1984年   9篇
  1983年   9篇
  1982年   13篇
  1981年   10篇
  1979年   14篇
  1977年   7篇
  1976年   9篇
  1975年   7篇
  1974年   9篇
  1973年   11篇
  1972年   12篇
  1970年   8篇
  1969年   10篇
  1968年   8篇
  1967年   7篇
排序方式: 共有1040条查询结果,搜索用时 0 毫秒
151.
Synergistic effects of ovine-derived cathelicidins SMAP29 and OaBac5mini with the antimicrobials polymyxin B, lysozyme, nisin and lactoferrin were investigated against E. coli O157:H7 and S. aureus 1056 MRSA. Lysozyme showed synergy against E. coli O157:H7 with SMAP29, polymyxin B and lactoferrin. Synergy was also found between SMAP29 and lactoferrin against this host. Against S. aureus 1056 MRSA, lysozyme showed synergy with OaBac5mini, polymyxin B and nisin, while synergy was also found between nisin and OaBac5mini and polymyxin B. Other combinations of the antimicrobials were either additive or non-synergistic.  相似文献   
152.
153.
Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans.  相似文献   
154.
155.
Bone turnover markers (BTMs) are classified as either formation or resorption markers. Their concentrations in blood or urine of adults are considered to reflect the rate of bone remodelling and may be of use in the management of patients with bone disease. Major inter-method differences exist for BTMs, and harmonisation of methods is currently being pursued at an international level. Based on published data, this article describes age- and sex-specific Australian consensus reference intervals for adults for serum procollagen type I amino-terminal propeptide (s-PINP) and serum β-isomerised carboxy-terminal cross-linking telopeptide of type I collagen (s-CTX).  相似文献   
156.
We have reported previously that tumour-promoting phorbol esters modulate both basal and vasoactive intestinal polypeptide (VIP)-stimulated adenylyl cyclase activity in GH3 (an established pituitary cell line). Here, we probe the receptor and cell specificity of this response. Experiments were performed in the presence of isobutylmethylxanthine. Unlike the response in GH3 cells, the tumour-promoting phorbol ester (tetradecanoyl phorbol acetate (TPA] did not affect either basal adenylyl cyclase activity nor VIP-stimulated activity in the rat osteosarcoma subclones UMR 106-01 and UMR 106-06. In addition, the cyclase responses to parathyroid hormone (PTH), and, in the case of UMR 106-06, to calcitonin were unaffected by tumour-promoting phorbol ester. However, prostaglandin E2-stimulated cyclase activity in both of these subclones was attenuated in a dose-dependent manner.  相似文献   
157.
Virus-specific polypeptide synthesis was examined in BHK cells and Vero cells infected with Bunyamwera virus. In BHK cells, in addition to the four previously reported virus-coded proteins (L, G1, G2, and N), three other infection-specific proteins were detected. These proteins, of nominal molecular weight 50,000 (p50), 16,000 (p16), and 13,000 (p13), were not labeled in mock-infected cells, were first synthesized between 4 and 8 h after infection, and were relatively prominent among the limited number of proteins generated late in infection. In preparations of purified Bunyamwera virus from BHK cell supernatants, p16 was detected but not p50 or p13. In Vero cells infected with Bunyamwera virus, both p50 and p13 were labeled strongly. Maprik virus, a member of the Mapputta group of arboviruses, is a member of the Bunyavirus genus (S.E. Newton, unpublished data). Maprik virus did not induce the synthesis of p50, p16, or p13; however, two smaller proteins (p17 and p15) which may correspond to p16 and p13 were labeled late in Maprik infection. Our data argue that p16 is a virus-coded component of the Bunyamwera virus particle and that p50 and p13 are virus-coded, nonstructural proteins.  相似文献   
158.
159.
160.
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