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   5683篇
  免费   792篇
  国内免费   9篇
耳鼻咽喉   25篇
儿科学   115篇
妇产科学   82篇
基础医学   774篇
口腔科学   128篇
临床医学   570篇
内科学   1320篇
皮肤病学   47篇
神经病学   461篇
特种医学   343篇
外科学   900篇
综合类   112篇
一般理论   2篇
预防医学   672篇
眼科学   52篇
药学   511篇
中国医学   2篇
肿瘤学   368篇
  2021年   90篇
  2019年   74篇
  2018年   96篇
  2017年   80篇
  2016年   99篇
  2015年   86篇
  2014年   129篇
  2013年   172篇
  2012年   247篇
  2011年   292篇
  2010年   166篇
  2009年   143篇
  2008年   220篇
  2007年   244篇
  2006年   268篇
  2005年   241篇
  2004年   249篇
  2003年   224篇
  2002年   235篇
  2001年   187篇
  2000年   215篇
  1999年   173篇
  1998年   83篇
  1997年   58篇
  1996年   57篇
  1995年   65篇
  1994年   52篇
  1993年   53篇
  1992年   119篇
  1991年   113篇
  1990年   109篇
  1989年   121篇
  1988年   108篇
  1987年   118篇
  1986年   119篇
  1985年   104篇
  1984年   105篇
  1983年   82篇
  1982年   57篇
  1981年   67篇
  1980年   45篇
  1979年   77篇
  1978年   46篇
  1977年   53篇
  1974年   54篇
  1973年   44篇
  1972年   62篇
  1970年   53篇
  1969年   45篇
  1968年   44篇
排序方式: 共有6484条查询结果,搜索用时 46 毫秒
1.
2.
3.
Addison's disease is rarely caused by metastatic cancer. We report a unique case of hypoadrenalism owing to metastatic transitional cell carcinoma of the bladder. The relevant literature is reviewed.  相似文献   
4.
White suckers, collected from lakes containing elevated levels of copper (12 micrograms liter-1) and zinc (250 micrograms liter-1), were evaluated for reproductive performance, growth and survival of the larvae, and tolerance of the larvae to waterborne copper. Fertilization success was not impaired in white suckers from contaminated sites; metal-exposed males performed better than control males in fertilization trials with control eggs. Larvae hatched from eggs collected at contaminated sites and fertilized in clean water were smaller, developed at a slightly increased rate, and exhibited poorer growth and survival than larvae from control sites. Larvae showed significant changes in resistance and tolerance to copper with age. During the period of endogenous nutrition, larvae from eggs taken at contaminated sites showed increased resistance and tolerance to waterborne copper relative to controls. The effect was not seen in larvae at first feeding, at ages older than 4 days after the onset of feeding (25 days posthatch) or in larvae hatched from control eggs fertilized with sperm from males taken at contaminated sites. This study provides evidence for a maternal yolk factor associated with increased tolerance and resistance of larvae to copper.  相似文献   
5.
1. The effects of nedocromil sodium and sodium cromoglycate on bronchoconstriction induced by inhaled sodium metabisulphite have been studied in eight atopic subjects, three of whom had mild asthma. 2. Nedocromil sodium (4 mg, 7.8 X 10(-6) M), sodium cromoglycate (10 mg, 24.1 X 10(-6) M) and matched placebo were administered by identical metered dose inhalers 30 min before a dose-response to sodium metabisulphite (5-100 mg ml-1) was performed. 3. Maximum fall in sGaw after placebo pre-treatment was -43.9 +/- 3.3% baseline (mean +/- s.e. mean). At the same metabisulphite concentration maximum fall in sGaw after sodium cromoglycate was -13.0 +/- 3.6% and after nedocromil sodium was +4.3 +/- 6.8%. Nedocromil sodium prevented any significant fall in sGaw even after higher concentrations of metabisulphite. 4. Both nedocromil sodium, 4 mg, and sodium cromoglycate, 10 mg, inhibited sodium metabisulphite induced bronchoconstriction but nedocromil sodium was significantly more effective. Relative in vivo potency of the two drugs is broadly in line with other in vivo and in vitro studies.  相似文献   
6.
Ventilator-dependent children are surviving longer and increasing in number. This qualitative study was undertaken to describe the impact of a ventilator-dependent child on 10 families and to describe the management styles used by the parents. In five families, the child remained hospitalized due to the disability while in the other five the child primarily lived at home. Three major themes in managing were elicited: barriers, resources, and parenting. Parents believed they should try to normalize their child's experiences, that interactions with health care professionals required negotiation and assertiveness, and that they needed some support person(s) outside of the family.  相似文献   
7.
D M Dixon  A Polak 《Chemotherapy》1987,33(2):129-140
Amphotericin B (Amph B), 5-fluorocytosine (5-FC), ketoconazole (KTZ), fluconazole (FLZ), amorolfine (AMOR) and terbinafine (TER) were tested against 3 agents of central nervous system phaeohyphomycosis in vitro and in life-threatening infections in mice. The fungi studied were Cladosporium bantianum, Dactylaria constricta and Wangiella dermatitidis. The broadest protection against this group of fungi in mice was offered by 5-FC followed by Amph B and FLZ, then KTZ. AMOR and TER were inactive in vivo. The results of in vitro susceptibility testing had no predictive value. In contrast, the data obtained from the mouse models should be useful clinically.  相似文献   
8.
9.
10.
Solitary microcarcinoid in ulcerative colitis.   总被引:1,自引:0,他引:1  
A Haidar  M F Dixon 《Histopathology》1992,21(5):487-488
  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