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   967篇
  免费   75篇
  国内免费   16篇
  2023年   35篇
  2022年   43篇
  2021年   93篇
  2020年   30篇
  2019年   37篇
  2018年   33篇
  2017年   31篇
  2016年   24篇
  2015年   50篇
  2014年   53篇
  2013年   66篇
  2012年   24篇
  2011年   16篇
  2010年   16篇
  2009年   17篇
  2008年   23篇
  2007年   27篇
  2006年   26篇
  2005年   20篇
  2004年   16篇
  2003年   11篇
  2002年   16篇
  2001年   9篇
  2000年   16篇
  1999年   8篇
  1998年   11篇
  1997年   13篇
  1996年   10篇
  1995年   16篇
  1994年   13篇
  1993年   12篇
  1992年   20篇
  1991年   16篇
  1990年   11篇
  1989年   16篇
  1988年   15篇
  1987年   19篇
  1986年   12篇
  1985年   17篇
  1984年   13篇
  1983年   14篇
  1982年   21篇
  1981年   25篇
  1980年   17篇
  1979年   6篇
  1978年   11篇
  1977年   5篇
  1976年   1篇
  1975年   3篇
  1973年   1篇
排序方式: 共有1058条查询结果,搜索用时 15 毫秒
1.
Serum samples of Meishan (13 animals) and Meishan x Wild Boar crosses (361 animals) were analysed by means of two-dimensional electrophoresis. Some new variants in protease inhibitor systems PO1A, PO1B and PI2 are reported.  相似文献   
2.
Abstract The 16S rRNA gene sequences of Rickettsia tsutsugamushi and Rickettsia sibirica were determined by PCR and DNA sequencing. Phylogenetic analysis revealed that R. sibirica is positioned in a cluster of the genus Rickettsia with a similarity value of 98.1–99.6%, whereas R. tsutsugamushi is located apart from the cluster with a similarity value of 90.2–90.6%. This evidence suggests that R. tsutsugamushi should be excluded taxonomically from the genus Rickettsia . The phylogenetic classification of six antigenic variants in R. tsutsugamushi moderately reflected their antigenic relationship known in closely and distantly related strains.  相似文献   
3.
《Molecular cell》2021,81(24):5099-5111.e8
  1. Download : Download high-res image (228KB)
  2. Download : Download full-size image
  相似文献   
4.
5.
Primary ciliary dyskinesia (PCD) is a group of genetically and clinically heterogeneous disorders with motile cilia dysfunction. It is clinically characterized by oto-sino-pulmonary diseases and subfertility, and half of the patients have situs inversus (Kartagener syndrome). To identify the genetic cause in a Han-Chinese pedigree, whole-exome sequencing was conducted in the 37-year-old proband, and then, Sanger sequencing was performed on available family members. Minigene splicing assay was applied to verify the impact of the splice-site variant. Compound heterozygous variants including a splice-site variant (c.1974-1G>C, rs1359107415) and a missense variant (c.7787G>A, p.(Arg2596Gln), rs780492669), in the dynein axonemal heavy chain 11 gene (DNAH11) were identified and confirmed as the disease-associated variants of this lineage. The minigene expression in vitro revealed that the c.1974-1G>C variant could cause skipping over exon 12, predicted to result in a truncated protein. This discovery may enlarge the DNAH11 variant spectrum of PCD, promote accurate genetic counselling and contribute to PCD diagnosis.  相似文献   
6.
Abstract: Electroconvulsive shock (ECS) administrations repeated for 10 consecutive days cause an elevation in the opioid content of the rat brain. Two different endogenous opioids, enkephalin and humoral-endorphin, undergo independent changes that differ in both their time course and intracerebral localization. These metabolic changes parallel long-term behavioral modifications such as the development and dissipation of tolerance to the analgesic effect of ECS. The activation of two different, independent, endogenous opioid systems by ECS is in agreement with previous behavioral and pharmacological studies.  相似文献   
7.
In a recent publication the isolation and some characteristics of an anti-histone 3 monoclonal antibody, 1GB3 were described (Muller et al. FEBS Lett. 182: 459–464, 1985). We now report that the epitope recognized is phylogenetically conserved and located in the N-terminal part of H3, most likely between residues 40 and 50. Using the ELISA technique we found this region to be accessible in chromatin to the monoclonal antibody. The effect of non-ionic detergents on the adsorbtion of chromatin on microtiter plates was studied in this context.Immunological analysis of the reaction of the monoclonal antibody with chromatin by immunoinhibition and immunosedimentation shows that the H3 epitope is accessible in both folded and unfolded chromatin fibre as well as in high- and low-molecular weight oligonucleosomes.Abbreviations BSA Bovine srum albumin - mab Monoclonal antibody - PBS Phosphate buffered saline - PMSF Phenylmethyl sulfonyl fluoride  相似文献   
8.
Immediate fragmentation of parental DNA by near-ultraviolet irradiation at 313 nm was measured in cultured skin fibroblasts from normal individuals, patients with Xeroderma pigmentosum of complementation group A (XPA) and Xeroderma pigmentosum variants (XPV) by the alkaline elution procedure. For a dose of 2.25 KJm?2 given at Oo fragmentation was comparable in all cell strains. However, fragmentation was strongly increased relative to Oo in XPV but not in normal fibroblasts and the XPA strains when irradiation was carried out at 37o. From our results it appears that a step in the repair of parental DNA is abnormal in XPV.  相似文献   
9.
Reticuloendotheliosis virus strain T (REV-T)-transformed cells gave rise spontaneously to variants which secrete a factor that forms a distinct visible ring of precipitation (halo) surrounding colonies grown in soft agar. An Mr 15,000 protein was produced at higher levels by halo variants than by nonhalo-producing cells. An assay designed to detect the formation of precipitates enabled purification of an Mr 15,000 protein, p15, from serum-free medium conditioned by the growth of REV-T-transformed hematopoietic cells. Fractions enriched in p15 permitted the growth of REV-T-transformed cells under conditions where they normally failed to proliferate.  相似文献   
10.
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