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   1154篇
  免费   76篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   24篇
妇产科学   18篇
基础医学   164篇
口腔科学   49篇
临床医学   105篇
内科学   179篇
皮肤病学   9篇
神经病学   94篇
特种医学   11篇
外科学   189篇
综合类   36篇
预防医学   163篇
眼科学   4篇
药学   70篇
中国医学   10篇
肿瘤学   103篇
  2024年   4篇
  2023年   14篇
  2022年   22篇
  2021年   53篇
  2020年   32篇
  2019年   37篇
  2018年   47篇
  2017年   29篇
  2016年   35篇
  2015年   36篇
  2014年   42篇
  2013年   62篇
  2012年   85篇
  2011年   96篇
  2010年   49篇
  2009年   48篇
  2008年   55篇
  2007年   74篇
  2006年   54篇
  2005年   74篇
  2004年   49篇
  2003年   51篇
  2002年   58篇
  2001年   14篇
  2000年   3篇
  1999年   6篇
  1998年   14篇
  1997年   7篇
  1996年   5篇
  1995年   6篇
  1994年   2篇
  1993年   8篇
  1992年   9篇
  1991年   2篇
  1990年   7篇
  1988年   4篇
  1987年   3篇
  1985年   2篇
  1984年   6篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1980年   5篇
  1978年   5篇
  1974年   2篇
  1967年   1篇
  1954年   1篇
  1946年   1篇
  1934年   1篇
  1933年   1篇
排序方式: 共有1233条查询结果,搜索用时 15 毫秒
1.
2.
3.
Observational and some experimental data suggest that hepatitis C virus can manifest in a variety of disease processes outside the liver. The links between hepatitis C virus and membranoproliferative glomerulonephropathy, porphyria cutanea tarda, lichen planus, cryoglobulinemia, diabetes mellitus, B-cell non-Hodgkin’s lymphoma, and thyroiditis are critically reviewed. Based on the available evidence, recommendations for the clinical approach to patients with extrahepatic diseases are discussed.  相似文献   
4.
5.
Vaccine development and our understanding of the pathology of bovine tuberculosis in cattle would be greatly facilitated by definition of the immunological correlates of protection and/or pathology. In this study we analyzed humoral immune responses in Mycobacterium bovis BCG-vaccinated and control cattle (in particular, the relationship between the intradermal comparative tuberculin skin test and serum immunoglobulin G [IgG] responses) against a range of mycobacterial antigens (MPB59, MPB64, MPB70, MPB83, ESAT-6, CFP-10, Acr1, and PstS-1) by multiantigen print immunoassay and conventional enzyme-linked immunosorbent assay. Following M. bovis infection, the comparative tuberculin skin test strongly boosted IgG, IgG1, and IgG2 antibody responses, particularly against MPB83 and MPB70, in unvaccinated cattle but failed to boost these responses, or did so only weakly, in BCG-vaccinated calves. In addition, the skin test-induced increases in MPB83-specific IgG responses correlated positively with bacterial loads and ESAT-6-induced in vitro gamma interferon responses. In conclusion, both the negative correlation of skin test-enhanced MPB83-specific antibody responses with BCG-induced protection and their positive correlation with bacterial loads can serve as useful markers for vaccine efficacy after challenge.  相似文献   
6.
This study examined the effects on food choice of increasing the number of healthy items available (fruit) and decreasing the number of unhealthy items available (candy bars). A similar choice, involving nonfood items, was also examined. Two hundred eighty-nine men and women were randomly assigned to 1 of 4 experimental groups: (a) control group, (b) increased number of fruits, (c) decreased number of candy bars, and (d) combination. Between 30% and 40% of participants chose fruit regardless of the amount of fruit and candy presented: there was no effect of increasing fruit or decreasing candy bars. However, restrained participants and current dieters were more likely to choose fruit. In contrast, both stimulus control techniques were effective in increasing the percentage of participants choosing a nonfood item. These results suggest that stimulus control may not be sufficient to modify food choice: other powerful factors affect eating behavior, and these must be considered.  相似文献   
7.
Studying the mechanisms of molecular interactions in developing tissues demands sensitive molecular biological in vivo and in vitro techniques. Laser capture microdissection (LCM) allows for the isolation of mRNA in histological sections even from single cells, thus enabling the identification of in vivo gene expression products in closely circumscribed tissue areas. The aims of this study were to assess the optimal fixation, processing, and staining conditions to retrieve RNA from microdissected odontoblasts. Fluorometric assays and RT-PCR analysis of alpha 1(I) collagen, dentin sialophosphoprotein (Dspp), and osteocalcin (OC) confirmed that the total RNA isolated from day 0 and day 3 captured odontoblasts was sufficient in quantity and quality. Our results indicate that individual odontoblasts obtained by LCM are morphologically intact and chemically unaltered, allowing accurate molecular and biochemical analyses.  相似文献   
8.
9.
To test the hypothesis that during high periods of carbon monoxide (CO) pollution, persons with acute cardiovascular disease would be adversely affected, we have studied case fatality rates for patients admitted with myocardial infarction (Ml) to 35 Los Angeles hospitals during 1958. The results indicate that there is an increased Ml case fatality rate in “high”-pollution areas and that this difference is only evident during periods of relatively increased CO pollution.

At the present time, our interpretation of these findings is that an association could exist between ME case fatality rate and atmospheric CO pollution but we cannot draw any firm conclusions about causality at this time.  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