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   1276671篇
  免费   99854篇
  国内免费   1989篇
耳鼻咽喉   18423篇
儿科学   44349篇
妇产科学   35009篇
基础医学   182174篇
口腔科学   33581篇
临床医学   111246篇
内科学   258218篇
皮肤病学   28020篇
神经病学   100361篇
特种医学   51198篇
外国民族医学   660篇
外科学   196398篇
综合类   27048篇
现状与发展   1篇
一般理论   377篇
预防医学   95716篇
眼科学   27912篇
药学   94764篇
  2篇
中国医学   2422篇
肿瘤学   70635篇
  2018年   13132篇
  2017年   9964篇
  2016年   10899篇
  2015年   12370篇
  2014年   17164篇
  2013年   26216篇
  2012年   36021篇
  2011年   38053篇
  2010年   22800篇
  2009年   21811篇
  2008年   36634篇
  2007年   39246篇
  2006年   39506篇
  2005年   38442篇
  2004年   37590篇
  2003年   36445篇
  2002年   35795篇
  2001年   63988篇
  2000年   66496篇
  1999年   56408篇
  1998年   15128篇
  1997年   13754篇
  1996年   14195篇
  1995年   13453篇
  1994年   12766篇
  1993年   11790篇
  1992年   44554篇
  1991年   43464篇
  1990年   42216篇
  1989年   40111篇
  1988年   36895篇
  1987年   36234篇
  1986年   33618篇
  1985年   32278篇
  1984年   24137篇
  1983年   20268篇
  1982年   11723篇
  1981年   10691篇
  1980年   9515篇
  1979年   21342篇
  1978年   14821篇
  1977年   12532篇
  1976年   11693篇
  1975年   12623篇
  1974年   14661篇
  1973年   14117篇
  1972年   12944篇
  1971年   11729篇
  1970年   11050篇
  1969年   10024篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
921.
922.
Results of an examination of 39 patients are described and critically assessed. An analysis of the resolving power of the method of ultrasonic angiography in pathological formations of major vessels of the neck is given.  相似文献   
923.
924.
925.
The behavioural and physiological consequences of social status and reciprocal fighting in resident-intruder dyads of Long Evans male rats were evaluated. Before a chronic cohabitation of 10 days, residents and intruders were individually housed for one month to increase their aggressiveness. Control animals included isolates, i.e., animals kept individually housed throughout the experiment and pair-housed rats, i.e., pairs of rats housed together from their rats in the laboratory. In 19 out of 20 dyads, a clear dominance relationship developed with an advantage to the resident in 68% of the cases. Dominants showed more exploratory activity than subordinates in a open-field test at the end of the cohabitation period; subordinates groomed longer than animals from other experimental groups. Dominants had lower pain thresholds than individually and pair-housed animals. Both dominants and subordinates had higher tyrosine hydroxylase enzymatic activities in the left adrenal than isolated and pair-housed rats. Subordinates lost body weight and had higher plasma corticosteroid concentrations than animals from the other experimental groups. In addition, they had smaller thymus glands and reduced spleen lymphocyte responses to mitogenic stimulation in vitro, in comparison to dominant animals. These results show that subordination in the dyadic resident-intruder paradigm leads to a complex syndrome of behavioural and physiological changes, some of which may be modulated by the intensity of aggressive interactions.  相似文献   
926.
The uptake of the phenanthridinium ethidium by the trypanosomatids Crithidia fasciculata and Leptomonas seymouri was studied. The time course of uptake of ethidium was biphasic for both organisms, consisting of an initial rapid phase and a protracted slow phase. The characteristics of these phases were consistent with the hypothesis that the initial phase represented specific external binding, while the second phase represented transport into the cells. In L. seymouri the transport phase was inhibited by inhibitors of energy transduction and putative inhibitors of a transport ATPase. Ethidium transport could not be saturated over a large concentration range of ethidium. Phenanthridiniums and related compounds displayed both inhibitory and stimulatory effects on ethidium transport.  相似文献   
927.
We describe a case of pathologic jealousy (Othello syndrome) in a patient with Parkinson disease, which abated after discontinuing amantadine. We indicate that early recognition and treatment of the syndrome in this disease may avert physical violence. We also believe that our report further suggests a link between this specific behavioral disorder and dopaminergic activity.  相似文献   
928.
Behavioral state-specific changes in human hippocampal theta activity   总被引:1,自引:0,他引:1  
Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms.  相似文献   
929.
930.
Because of the trend toward a marked decrease in length of psychiatric hospitalization, clinicians need to improve the organization of the therapeutic milieu so that behavioral changes can be effected more rapidly. A university general psychiatric unit has adapted a problem-solving model that integrates groups and activities so that each one focuses on complementary behavioral objectives for each patient with the aim of effecting more rapid behavior change. The stages of the model are incorporated in a weekly sequence that begins with a goal-setting group. In a series of subsequent groups, each patient tries to develop and implement a solution to the problem identified that week. At the end of each week, patients participate in a goal review group, with feedback from staff and peers and self-reinforcement. The model can be used with a diverse patient population without interfering with each patient's individual psychotherapy or pharmacotherapy.  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