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   34389篇
  免费   1709篇
  国内免费   210篇
耳鼻咽喉   384篇
儿科学   493篇
妇产科学   650篇
基础医学   4323篇
口腔科学   734篇
临床医学   2433篇
内科学   9629篇
皮肤病学   467篇
神经病学   2478篇
特种医学   1222篇
外科学   6084篇
综合类   182篇
一般理论   1篇
预防医学   885篇
眼科学   458篇
药学   2334篇
  4篇
中国医学   84篇
肿瘤学   3463篇
  2023年   168篇
  2022年   322篇
  2021年   687篇
  2020年   365篇
  2019年   446篇
  2018年   627篇
  2017年   499篇
  2016年   625篇
  2015年   655篇
  2014年   853篇
  2013年   1023篇
  2012年   1667篇
  2011年   1835篇
  2010年   979篇
  2009年   915篇
  2008年   1695篇
  2007年   1913篇
  2006年   1800篇
  2005年   1750篇
  2004年   1736篇
  2003年   1759篇
  2002年   1721篇
  2001年   1013篇
  2000年   999篇
  1999年   931篇
  1998年   486篇
  1997年   374篇
  1996年   327篇
  1995年   310篇
  1994年   246篇
  1993年   242篇
  1992年   663篇
  1991年   667篇
  1990年   583篇
  1989年   578篇
  1988年   557篇
  1987年   526篇
  1986年   450篇
  1985年   440篇
  1984年   332篇
  1983年   256篇
  1979年   239篇
  1978年   141篇
  1977年   142篇
  1974年   135篇
  1973年   123篇
  1972年   139篇
  1971年   129篇
  1969年   139篇
  1967年   131篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Few studies have demonstrated the optimal usage of common inflammatory markers, alone or in combination, based on the cost-effectiveness. We analyzed the yield and cost of C-reactive protein (CRP), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), sialic acid, and protein fractionation in 177 new primary care outpatients with inflammation-related symptoms. A useful result (UR) was assigned if tests contributed to a change in physician's diagnosis or decision-making. Costs of testing were calculated based on either single or simultaneous measurement. Five inflammatory markers generated 147 URs in 123 patients. CRP showed the best contribution to generation of UR, followed by sialic acid, protein fractionation, WBC, and ESR. CRP demonstrated poor correlation with WBC (r = 0.458), while sialic acid strongly correlated with total absolute amount of alpha1 and alpha2 fractions in protein fractionation (r = 0.855) and moderately with ESR (r = 0.651). The combination of CRP and WBC produced the best cost-effectiveness at a cost of Yen 1169 (US dollars 9.6 or Euro 9.7)/additional UR against CRP testing alone. Sialic acid, an automated multichannel analyzer-based test, demonstrated the favorable cost-effectiveness over ESR or protein fractionation when combined with CRP (and WBC). Our results indicate that the optimal usage of these inflammatory markers should involve careful cost-effectiveness considerations.  相似文献   
7.
8.
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN.  相似文献   
9.
10.
Inter-individual variations in the development of silicosis, even within the same environments, have been reported, which suggest the contribution of genetic factors in silicosis aetiology. The aim of the present study was to determine whether there is any significant genetic influence on the development of silicosis. Furthermore, which genetic loci are responsible for the pulmonary response to silica exposure? Eight strains of inbred mice were used to examine the genetic influence on the lung fibrotic response to silica exposure. After intercross-breeding between the most susceptible and most resistant strains, a genome-wide linkage analysis of quantitative trait loci (QTL) was performed. Hydroxyproline was applied as an index, and genotypes of 167 marker genes were analysed by fragment analysis using a capillary-type sequencer. There was significant inter-strain difference in the mean concentration of hydroxyproline contents among the eight strains of mice. Breeding studies were conducted between the most susceptible, C57BL/6J, and the most resistant strain, CBA/J. A genome-wide linkage analysis of silica-exposed intercrossed cohorts identified significant QTL on chromosome 4 and suggestive QTL on chromosomes 3 and 18. The present study demonstrates that genetic factors may play a significant role in fibrotic-lung responses to silica; one significant and two suggestive quantitative trait loci were identified.  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