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   895篇
  免费   79篇
  国内免费   1篇
耳鼻咽喉   9篇
儿科学   19篇
妇产科学   17篇
基础医学   157篇
口腔科学   7篇
临床医学   151篇
内科学   166篇
皮肤病学   46篇
神经病学   97篇
特种医学   14篇
外科学   57篇
综合类   13篇
一般理论   3篇
预防医学   109篇
眼科学   7篇
药学   58篇
中国医学   3篇
肿瘤学   42篇
  2023年   11篇
  2022年   16篇
  2021年   21篇
  2020年   20篇
  2019年   34篇
  2018年   25篇
  2017年   19篇
  2016年   32篇
  2015年   30篇
  2014年   19篇
  2013年   42篇
  2012年   36篇
  2011年   62篇
  2010年   30篇
  2009年   17篇
  2008年   49篇
  2007年   63篇
  2006年   58篇
  2005年   35篇
  2004年   51篇
  2003年   40篇
  2002年   43篇
  2001年   6篇
  2000年   9篇
  1999年   13篇
  1998年   12篇
  1997年   6篇
  1996年   13篇
  1995年   8篇
  1994年   9篇
  1993年   7篇
  1992年   7篇
  1991年   7篇
  1990年   4篇
  1989年   7篇
  1988年   3篇
  1987年   9篇
  1984年   9篇
  1983年   9篇
  1982年   12篇
  1981年   10篇
  1980年   5篇
  1979年   4篇
  1978年   3篇
  1977年   3篇
  1976年   6篇
  1975年   5篇
  1963年   3篇
  1959年   3篇
  1946年   2篇
排序方式: 共有975条查询结果,搜索用时 15 毫秒
1.
Ecotoxicology - The availability of pharmaceutically active compounds (PhACs) in surface waters and suspended solids/sediments presents an ecological hazard of chronic exposure to non-target...  相似文献   
2.
3.
4.
5.
P-fimbriae vaccines   总被引:3,自引:0,他引:3  
To test for cross-protective capacity of two different P-fimbriae vaccines we vaccinated baboons with fimbriae purified from either Escherichia coli strain ER2 or strain JR1. The vaccinated animals showed elevated antibody titers to P-fimbriae from each of the E. coli strains used, suggesting cross-reactivity as was expected from the results of immunoprecipitation of the fimbriae. Enzyme-linked immunosorbent assay inhibition by heterologous P-fimbriae proved this to be true immunologic cross-reactivity.  相似文献   
6.
To determine the extent to which social support from the spouse and a health care provider (HCP) is associated with short- and long-term recovery outcomes in individuals after a cardiac illness, 93 patients were interviewed 2 months (short-term) after their event; 73 (78%) subjects responded to a follow-up questionnaire 1 year later (long-term). Tangible aid from the spouse was associated with better short-term psychological recovery. Satisfaction with and more emotional support from the spouse were associated with better short- and long-term psychological recovery outcomes. Greater satisfaction with HCP support was associated with patients' short- and long-term physical recoveries. These results highlight the value of different sources and types of support as having differential effects on physical and psychological recovery outcomes. ©1995 John Wiley & Sons, Inc.  相似文献   
7.
Summary Human platelet membranes were solubilized with the zwitterionic detergent CHAPS (3-[3-(cholamidopropyl)dimethylammonio]-1-propanesulfonate) and the solubilized extract subjected to gel filtration. Binding of the adenosine receptor agonist [3H]NECA (5-N-ethylcarboxamidoadeno-sine) was measured to the eluted fractions. Two [3H]NECA binding peaks were eluted, the first of them with the void volume. This first peak represented between 10% and 25% of the [3H]NECA binding activity eluted from the column. It bound [3H]NECA in a reversible, saturable and GTP-dependent manner with an affinity of 46 nmol/1 and a binding capacity of 510 fmol/mg protein. Various adenosine receptor ligands competed for the binding of [3H]NECA to the first peak with a pharmacological profile characteristic for the A2 adenosine receptor as determined from adenylate cyclase experiments. In contrast, most adenosine receptor ligands did not compete for [3H]NECA binding to the second, major peak. These results suggest that a solubilized A2 receptor-GS protein complex of human platelets can be separated from other [3H]NECA binding sites by gel filtration. This allows reliable radioligand binding studies of the A2 adenosine receptor of human platelets.Abbreviations CHAPS 3-[3-(cholamidopropyl)dimethylammoniol-l-propanesulfonate - CIA 2-chloroadenosine - CPA N6-cyclopentyladenosine - DPX 1,3-diethyl-8-phenylxanthine - NECA 5-N-ethylcarboxamidoadenosine - PAA 2-phenylaminoadenosine - PIA N6-phenyhsopropyladenosine - XAC 8-{4-[([{(2-aminoethyl)amino}carbonyl}methyl)oxy]phenyl]-1,3-dipropylxanthine Send offprint requests to M. J. Lohse  相似文献   
8.
The effects of self-generated expectancy of stimulus content on the visual evoked potential to physically identical stimuli were studied in college students. The subject set up his own internal expectant; by choosing to see either a bright or dim Hash. When a bright or dim Hash was anticipated, the potentials evoked by u medium stimulus intensity resembled the responses elicited by an actual bright or dim flash, respectively. Significant differences in visual evoked potential amplitude were obtained between identical medium intensity stimuli depending on the stimulus intensity expected, despite (he constant physical properties of the stimulus. 1 In1 results suggest that a subject's expectancy of certain physical parameters of a stimulus are as important In determining (he resultant visual evoked potential as the actual physical features of the stimulus.  相似文献   
9.
The rare apolipoprotein C-II (apoC-II) mutation, apoC-IILys19→Thr, also known as apoC-II-v, has been found previously in association with hyperlipoproteinemia. From a lipid clinic screening we identified three unrelated individuals who had the apoC-IILys19→Thr mutation. Among eight family members of one proband, we have found another four who were affected. None of the inviduals in this kindred is dyslipidemic and there is no difference in lipid levels between affected and unaffected family members. Therefore, we conclude that the presence of this apolipoprotein variant by itself has no effect on lipoprotein levels. In addition, the apolipoprotein E (apoE) isoform, apoE4 does not have a synergistic effect on lipoprotein levels in this kindred, in contrast to observations on the interaction of apoE4 with another apoC-II mutant (apoC-IIToronto). The single nucleotide substitution that causes the apoC-IILys19→Thr variant introduces a previously unrecognized restriction site (for Mae III), that provides for easy screening.  相似文献   
10.
We describe a 59-year-old male (patient A059) with moderate to severe mental retardation (MR) and a pericentric inversion of the X-chromosome: inv(X)(p21.1;q22.1). He had short stature, pectus excavatum, general muscle wasting, and facial dysmorphism. Until now, no other patients with similar clinical features have been described in the literature. Molecular analysis of both breakpoints led to the identification of a novel "Nuclear RNA export factor" (NXF) gene cluster on Xq22.1. Within this cluster, the NXF5 gene was interrupted with subsequent loss of gene expression. Hence, mutation analysis of the NXF5 and its neighboring homologue, the NXF2 gene was performed in 45 men with various forms of syndromic X-linked MR (XLMR) and in 70 patients with nonspecific XLMR. In the NXF5 gene four nucleotide changes: one intronic, two silent, and one missense (K23E), were identified. In the NXF2 gene two changes (one intronic and one silent) were found. Although none of these changes were causative mutations, we propose that NXF5 is a good candidate gene for this syndromic form of XLMR, given the suspected role of NXF proteins is within mRNA export/transport in neurons. Therefore, mutation screening of the NXF gene family in phenotypically identical patients is recommended.  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