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   9313篇
  免费   933篇
  国内免费   10篇
  2021年   128篇
  2020年   76篇
  2019年   109篇
  2018年   152篇
  2017年   129篇
  2016年   199篇
  2015年   368篇
  2014年   426篇
  2013年   525篇
  2012年   646篇
  2011年   657篇
  2010年   450篇
  2009年   443篇
  2008年   579篇
  2007年   595篇
  2006年   542篇
  2005年   531篇
  2004年   536篇
  2003年   501篇
  2002年   487篇
  2001年   95篇
  2000年   77篇
  1999年   108篇
  1998年   134篇
  1997年   87篇
  1996年   86篇
  1995年   82篇
  1994年   88篇
  1993年   82篇
  1992年   73篇
  1991年   68篇
  1990年   83篇
  1989年   57篇
  1988年   58篇
  1987年   59篇
  1986年   47篇
  1985年   63篇
  1984年   61篇
  1983年   60篇
  1982年   65篇
  1981年   61篇
  1980年   63篇
  1979年   49篇
  1978年   42篇
  1977年   43篇
  1976年   50篇
  1974年   39篇
  1973年   47篇
  1971年   24篇
  1970年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
People are biased partisans: they tend to agree with policies from political parties they identify with, independent of policy content. Here, we investigate how physiological reactions to political parties shape bias. Using changes in galvanic skin conductance responses to the visual presentation of party logos, we obtained an implicit and physiological measure of the affective arousal associated with political parties. Subsequently, we exposed subjects to classical party cue experiments where the party sponsors of specific policies were experimentally varied. We found that partisan bias only obtains among those exhibiting a strong physiological reaction to the party source; being a self-reported party identifier is not sufficient on its own. This suggests that partisan bias is rooted in implicit, affective reactions.  相似文献   
3.
Abstract: Monoamine-uptake blockers were applied focally (0.1–1,000 µ M ) through a dialysis probe in the nucleus accumbens of freely moving rats, and the extracellular concentrations of dopamine, norepinephrine, and serotonin were measured. The selective dopamine-uptake blocker GBR 12935 increased dopamine preferentially with only a small effect on norepinephrine, whereas the selective serotonin-uptake blocker fluoxetine increased serotonin output preferentially. In contrast, the selective norepinephrine-uptake blockers desipramine and nisoxetine enhanced not only norepinephrine, but also serotonin and dopamine appreciably. Cocaine increased all three amines with the greatest effects on dopamine and serotonin. As in our previous study on the ventral tegmental area, there was a positive association between dopamine and norepinephrine output when all blocker data were taken together. The present results suggest a contribution of the increase in norepinephrine, but not serotonin, to the enhancement of dopamine after cocaine applied focally in the nucleus accumbens.  相似文献   
4.
The process of ageing is associated with increased susceptibility to infection. Phagocytes form the primary defence mechanism against infecting microorganisms, but the influence of ageing on phagocyte function remains controversial. In this study we have applied a microtitre plate phagocyte chemiluminescence (CL) assay suitable for clinical use to compare phagocyte oxidative metabolism in younger healthy subjects (age 20–60 years) and healthy older (60–70 years) subjects. Polymorphonuclear leukocytes (PMNL) and monocytes were stimulated using phorbol myristate acetate (PMA), serum opsonized zymosan (SOZ), and non-opsonized zymosan (ZYM) in the presence of both lucigenin and luminol. Monocytes showed a higher luminolenhanced CL response to PMA in males compared with females in the younger age group. No PMNL differences were observed between the sexes. Although no difference were found in relation to age when cells were stimulated with PMA and SOZ, significantly lower background (unstimulated) CL was obtained from PMNL with luminol. PMNL luminol-enhanced CL responses were also lower in response to ZYM. The findings suggest a reduced response of PMNL from older subjects to minimal stimulation. This could be related to abnormalities in the triggering of the respiratory burst or myeloperoxidase release due to ageing. The influence of age and sex should be taken into account in clinical studies of phagocyte CL.  相似文献   
5.
6.
Mitosis     
Within the last decade, the study of mitosis has evolved into a multidisciplinary science in which findings from fields as diverse as chromosome biology and cytoskeletal architecture have converged to present a more cohesive understanding of the complex events that occur when cells divide. The largest strides have been made in the identification and characterization of regulatory enzymes (kinases and phosphatases) that modulate mitotic activity, as well as a number of the proteins and structural components (spindle, chromosomes, nuclear envelope) which carry out the mitotic instructions. One emerging theme appears to be that molecular signalling, which can involve modification of components (such as phosphorylation) or even their specific destruction, monitors the state of the mitotic cell at all stages. One of the major challenges for the future will be the identification of addititonal targets of the signalling machinery, as well as new regulatory components and their targets on the chromosomes, on the spindle, and at the cleavage furrow.  相似文献   
7.
8.
9.
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