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   2373篇
  免费   165篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   64篇
妇产科学   44篇
基础医学   332篇
口腔科学   118篇
临床医学   147篇
内科学   488篇
皮肤病学   14篇
神经病学   153篇
特种医学   134篇
外科学   263篇
综合类   138篇
一般理论   4篇
预防医学   232篇
眼科学   20篇
药学   156篇
中国医学   5篇
肿瘤学   221篇
  2022年   13篇
  2021年   43篇
  2020年   14篇
  2019年   30篇
  2018年   29篇
  2017年   38篇
  2016年   39篇
  2015年   36篇
  2014年   46篇
  2013年   58篇
  2012年   87篇
  2011年   77篇
  2010年   67篇
  2009年   57篇
  2008年   109篇
  2007年   97篇
  2006年   133篇
  2005年   109篇
  2004年   101篇
  2003年   94篇
  2002年   78篇
  2001年   62篇
  2000年   66篇
  1999年   78篇
  1998年   74篇
  1997年   47篇
  1996年   52篇
  1995年   45篇
  1994年   58篇
  1993年   28篇
  1992年   47篇
  1991年   31篇
  1990年   34篇
  1989年   50篇
  1988年   42篇
  1987年   47篇
  1986年   50篇
  1985年   42篇
  1984年   27篇
  1983年   26篇
  1982年   29篇
  1981年   23篇
  1980年   20篇
  1979年   16篇
  1978年   16篇
  1977年   19篇
  1976年   13篇
  1975年   15篇
  1972年   13篇
  1969年   12篇
排序方式: 共有2542条查询结果,搜索用时 15 毫秒
31.
Behavior Genetics - Trajectories of youth antisocial behavior (ASB) are characterized by both continuity and change. Twin studies have further indicated that genetic factors underlie continuity,...  相似文献   
32.
Hogge  DE; Humphries  RK 《Blood》1987,69(2):611-617
To study the feasibility of using retroviruses for gene transfer into human hemopoietic cells, various cell types were exposed to virus carrying the gene for neomycin resistance (neor). In preliminary studies using K562 cells as targets, we found that high viral titer and co-cultivation with viral producer cells rather than incubation in medium exposed to viral producer cells were important variables for achieving high frequencies of G418 resistant (G418r) colonies. The maximum frequency of G418r K562 colonies after co-cultivation with cells producing a neor virus titer of 4 X 10(6) cfu/mL was 60%. When primary human progenitors from normal marrow, fetal liver, or chronic myelogenous leukemia blood were exposed to high titer viral stocks, both with and without helper virus, under conditions optimized for K562 cells, maximum frequencies of G418r colonies were 3% to 16% for granulocyte macrophage progenitors and 2% to 6% for primitive erythroid progenitors. The presence of the neor gene in both G418r K562 and primary hemopoietic colonies was verified by Southern blot. Expression of the neor gene was shown by RNA spot blot. These data demonstrate efficient transfer and expression of the neor gene in both K562 cells and primary human hemopoietic cells from normal and leukemic individuals.  相似文献   
33.
34.
35.
36.
37.
Journal of Neurology - To investigate the results of real-world application of non-myeloablative autologous HSCT for multiple sclerosis (MS). Between July 2003 and October 2019 at a single center...  相似文献   
38.
Preferences for symmetry in faces change across the menstrual cycle   总被引:1,自引:0,他引:1  
Symmetry in human male faces may be a cue to heritable fitness benefits and is found attractive. Preferences for facial masculinity, another proposed marker of genetic quality, have been found to vary in ways that may maximise evolutionary relevant benefits and masculinity is found to be of increased attractiveness at peak fertility across the menstrual cycle. Here we show that women prefer more symmetric faces at peak fertility (Study 1) and that such shifting preferences may be potentially strategic preferences as we found them to occur only for judgements concerning short-term relations and when women already had a partner (Study 2). Such preferences potentially indicate a strategy that maximises the quality of extra-pair/short-term partners or a quality dependent response to hormones. Such strategic preferences for symmetry may support the role of symmetry in signalling potential good-gene benefits.  相似文献   
39.
Cai  SP; Chang  CA; Zhang  JZ; Saiki  RK; Erlich  HA; Kan  YW 《Blood》1989,73(2):372-374
We used in vitro DNA amplification by the polymerase chain reaction and nonradioactive probes for prenatal diagnosis of beta thalassemia in Chinese from the Guangdong province. Exact molecular diagnoses were made in all 20 fetuses studied over a 6-month period. We conclude that this method of prenatal diagnosis for beta thalassemia is a viable approach in many parts of the world where this disease is common.  相似文献   
40.
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