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   3127904篇
  免费   237175篇
  国内免费   5228篇
耳鼻咽喉   45522篇
儿科学   98327篇
妇产科学   83040篇
基础医学   440104篇
口腔科学   89911篇
临床医学   283342篇
内科学   603935篇
皮肤病学   65825篇
神经病学   255702篇
特种医学   124477篇
外国民族医学   1082篇
外科学   472979篇
综合类   72139篇
现状与发展   2篇
一般理论   1200篇
预防医学   244626篇
眼科学   73984篇
药学   238359篇
  11篇
中国医学   6379篇
肿瘤学   169361篇
  2018年   31942篇
  2017年   24722篇
  2016年   27432篇
  2015年   30862篇
  2014年   44034篇
  2013年   66381篇
  2012年   89950篇
  2011年   95037篇
  2010年   56104篇
  2009年   53370篇
  2008年   89567篇
  2007年   95758篇
  2006年   96992篇
  2005年   93794篇
  2004年   90347篇
  2003年   87151篇
  2002年   85683篇
  2001年   149280篇
  2000年   154576篇
  1999年   130481篇
  1998年   36507篇
  1997年   32884篇
  1996年   32660篇
  1995年   31326篇
  1994年   29282篇
  1993年   27362篇
  1992年   104106篇
  1991年   100411篇
  1990年   97268篇
  1989年   93950篇
  1988年   86899篇
  1987年   85231篇
  1986年   80855篇
  1985年   77007篇
  1984年   57616篇
  1983年   48984篇
  1982年   29069篇
  1981年   25689篇
  1979年   53638篇
  1978年   37225篇
  1977年   32000篇
  1976年   29369篇
  1975年   31637篇
  1974年   38523篇
  1973年   36653篇
  1972年   34505篇
  1971年   32061篇
  1970年   30102篇
  1969年   28233篇
  1968年   25544篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
991.
992.
Bromocriptine (0.5 mg/kg) and apomorphine (0.03 mg/kg) exert moderate aphrodisiac effect in sexually sluggish rats. This effect appears rapidly and reaches its peak within 24 h. Amphetamine (2 mg/kg) acts similarly but with a more rapid onset and offset of the effect. A single dose of (-)deprenyl, a selective inhibitor of MAO-B, exerts a much more potent effect in this test.  相似文献   
993.
994.
Summary The left recurrent laryngeal nerves from five horses with sub-clinical neuropathy were examined by light and electron microscopy in a study designed to examine accumulation of axonal organelles at paranodal and internodal locations. Transverse sections of the nerve showed scattered fibres with split myelin sheaths and axonal accumulation of organelles. On longitudinal sections these collections were seen to result from an axonal outpouching in which dense lamellar bodies and mitochondria had accumulated. These paranodal collections, which could be found on both sides of the node, were often associated with infoldings of the terminal loops of myelin and with occasional paranodal demyelination. The fact that many of the organelles in the outpouches were lysosomal in nature was confirmed by their positive staining for cathepsin D activity. Longitudinal sections demonstrated a number of axons which were swollen over a long distance and which contained focal accumulations of similar organelles. In places, however, there was a clear separation between these organelles and the cytoskeletal proteins. In each case these swollen axons were surrounded by Schwann cell nuclei and their processes, forming well-ordered onion bulbs. The possibility that these two types of changes, i.e. the paranodal accumulations and the axonal swellings could result from a disturbance in axonal transport in this distal axonopathy is discussed.  相似文献   
995.
996.
Trends in analgesic self-poisoning in West-Fife, 1971-1985   总被引:1,自引:0,他引:1  
All admissions for analgesic self-poisoning to a district poisons unit over a 15-year period have been reviewed. During this time overdose with analgesic drugs increased to represent almost half of all admissions for self-poisoning. The types of analgesics taken in overdose also changed significantly during the period of this review. Aspirin and Distalgesic poisoning declined in incidence and more cases of self-poisoning by paracetamol and non-steroidal anti-inflammatory agents were seen. The impact of these changes on the medical management and outcome of deliberate self-poisoning is analysed. The reasons behind the trends described in this paper are assessed and their implications for future prevention and treatment are discussed.  相似文献   
997.
We review evidence suggesting that deaf speakers do not move their articulators toward the following open posture throughout closure and report results from a preliminary cinefluorographic study. Two prelingually deaf and two hearing speakers produced two different strings of alternating heterogeneous monosyllables as though speaking in time with a metronome (the so-called P-center task). Events traditionally associated with vowel production appeared evenly timed throughout the productions, and, in general, the deaf speakers performed similarly to the hearing speakers. We relate the results to Fowler's (1983) interpretation of the P-center phenomenon as an indicant of continuous vowel production.  相似文献   
998.
The purpose of this study was to determine whether blood lipid and lipoprotein concentrations varied in 5 men with advanced HIV-1 infection after 12 months of aerobic exercise training. Prior to exercise, the mean baseline cholesterol and high-density lipoprotein cholesterol (HDL-C) serum concentration were each lower, and mean baseline triglyceride concentration was higher compared to a healthy population norm. Consistent exercise training for 12 months failed to significantly (p > .05) alter cholesterol or HDL-C. Triglyceride concentration was significantly (p < .05) elevated above baseline (63 mg/dL) regardless of exercise compliance. The results suggest that long-term exercise training cannot correct lipid profile abnormality, particularly hypertriglyceridemia, common to individuals with advanced HIV-1 infection.  相似文献   
999.
1000.
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