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   2350810篇
  免费   171650篇
  国内免费   3331篇
耳鼻咽喉   32072篇
儿科学   75955篇
妇产科学   62716篇
基础医学   348229篇
口腔科学   63665篇
临床医学   211403篇
内科学   457492篇
皮肤病学   51733篇
神经病学   185351篇
特种医学   88063篇
外国民族医学   489篇
外科学   354066篇
综合类   47523篇
现状与发展   12篇
一般理论   848篇
预防医学   182812篇
眼科学   54356篇
药学   175158篇
  11篇
中国医学   4575篇
肿瘤学   129262篇
  2021年   18988篇
  2019年   19541篇
  2018年   27116篇
  2017年   20405篇
  2016年   22821篇
  2015年   25647篇
  2014年   36109篇
  2013年   53970篇
  2012年   74716篇
  2011年   79508篇
  2010年   47106篇
  2009年   44631篇
  2008年   74697篇
  2007年   79607篇
  2006年   80316篇
  2005年   77793篇
  2004年   74395篇
  2003年   71729篇
  2002年   69403篇
  2001年   108745篇
  2000年   111466篇
  1999年   93506篇
  1998年   26996篇
  1997年   23659篇
  1996年   24057篇
  1995年   22719篇
  1994年   20894篇
  1993年   19713篇
  1992年   72002篇
  1991年   70074篇
  1990年   68397篇
  1989年   65668篇
  1988年   60304篇
  1987年   59135篇
  1986年   55221篇
  1985年   53005篇
  1984年   39313篇
  1983年   33402篇
  1982年   19858篇
  1979年   35872篇
  1978年   25654篇
  1977年   21231篇
  1976年   20336篇
  1975年   21828篇
  1974年   26159篇
  1973年   24815篇
  1972年   23213篇
  1971年   22047篇
  1970年   20257篇
  1969年   19319篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Many types of seafood require cooking before ingestion and it has been demonstrated that this cooking process may affect the antigenicity and allergenicity of the food. We describe a case of anaphylaxis caused by selective sensitization to razor shell, a mollusc. In vivo and in vitro studies confirmed sensitization to boiled razor shell. Analysis of the nature of the allergen yielded results that were consistent with the findings of other authors and suggested that allergens involved in seafood allergy are commonly high molecular weight proteins that, in most cases, are heat stable.  相似文献   
952.
953.
Migräne     
Migraine is a prevalent disease that affects women more frequently than men. A particular trigger for migraine is the perimenstrual period. Acute migraine attacks during menstruation are treated similarly to nonmenstrual attacks, e.g., with analgesics or triptans. In women with pure menstrual migraine, short-term prophylaxis can be performed with nonsteroidal anti-inflammatory drugs (NSAIDs), estrogens, or low-dose triptans. During pregnancy migraine improves. After menopause frequency and severity of migraine attacks improve.  相似文献   
954.
955.
956.
957.
958.
Operator's determined (D) and stochastic (S) performance depends on the level of readiness and synchronization of the frontoparietal and parietooccipital cortex areas. The developed feedback algorithm was tested in two series of experiments with volunteered subjects doing computer simulation tasks. The experiments showed feasibility to elaborate feedback adaptive control skills that will sustain for a month period.  相似文献   
959.
Head-down tilting of primates (HOT) is a universal method of studying the hypokinetic syndrome effects on functionality of various body systems. Clinical biochemical blood assay was performed in a 25-day HDT experiment (-5 degrees) with 11 Macaca rhesus. One group of animals was kept tilted all the time through, whereas the other was periodically returned into the orthostatic position for 30 to 120 minutes 4-5 times a week. Dry chemistry was employed in biochemical analysis of blood serum and enzyme immunodetection (EID) in measuring blood hormones. As a rule, the biochemical parameters of primates' serum were within the physiological norm range. Shifts in protein, carbohydrate and mineral metabolism were sought for and enzymic activity in blood serum and hormone concentrations were determined. HDT did not produce noteworthy changes in blood concentrations of somatotropic hormone, thyrotrophic hormone (TTH), triiodothyronine (T3), thyroxine (T4) or cortisol. Animals of both groups showed statistically reliable decrease in blood osteocalcine. The preventive complex did not contribute materially to the control of metabolic homeostasis and endocrine function of the primates adapting to the 25-day HDT.  相似文献   
960.
Experiments on Japanese quail embryogenesis on a background of chronic exposure to gamma- and neutron doses comparable with the doses of ionized radiation inside the orbital space stations Mir and ISS, and exploration vehicles gave evidence that permanent absorption of low gamma-doses (0,15 cgy/d) did not impact development of the Japanese quail embryos. On the contrary, the neutron dose of 200 microgy/d imparted by the neutron flux of 30 particles/cm2s was hazardous to embryos as it caused morphological disorders in 12% of embryos.  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