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   2705篇
  免费   162篇
  国内免费   11篇
耳鼻咽喉   13篇
儿科学   81篇
妇产科学   69篇
基础医学   341篇
口腔科学   22篇
临床医学   283篇
内科学   738篇
皮肤病学   117篇
神经病学   143篇
特种医学   194篇
外科学   299篇
综合类   15篇
预防医学   123篇
眼科学   49篇
药学   182篇
  2篇
中国医学   1篇
肿瘤学   206篇
  2023年   13篇
  2022年   23篇
  2021年   39篇
  2020年   23篇
  2019年   28篇
  2018年   54篇
  2017年   36篇
  2016年   44篇
  2015年   38篇
  2014年   60篇
  2013年   85篇
  2012年   126篇
  2011年   128篇
  2010年   91篇
  2009年   86篇
  2008年   116篇
  2007年   131篇
  2006年   128篇
  2005年   104篇
  2004年   106篇
  2003年   109篇
  2002年   112篇
  2001年   113篇
  2000年   105篇
  1999年   89篇
  1998年   53篇
  1997年   36篇
  1996年   48篇
  1995年   38篇
  1994年   39篇
  1993年   27篇
  1992年   76篇
  1991年   65篇
  1990年   51篇
  1989年   61篇
  1988年   55篇
  1987年   55篇
  1986年   42篇
  1985年   47篇
  1984年   21篇
  1983年   21篇
  1982年   9篇
  1981年   16篇
  1980年   14篇
  1979年   23篇
  1978年   14篇
  1977年   9篇
  1976年   17篇
  1975年   10篇
  1974年   9篇
排序方式: 共有2878条查询结果,搜索用时 15 毫秒
1.
2.
Beta-blockers are among the most widely used antihypertensive drugs. They differ from each other in regard to several factors such as: beta-agonist activity, beta 1-selectivity and solubility. Aim of this work was to evaluate the influence of obesity on the kinetics and the antihypertensive effect of two Beta-blockers with different solubility such as: the water-soluble, atenolol and the liposoluble, metoprolol. The study was carried out according to an open randomized cross-over design. Eight obese hypertensive patients, after a two week washout period, were randomly allocated to a four week treatment. After a two week intermediate washout period, each patient switched to the other treatment for an additional four week period. On the first and the last day of each treatment the subjects were hospitalized to collect blood samples for the assay of the two drugs and to measure cardiovascular parameters. Obesity does not exert any effect on the kinetics of the water-soluble beta-blocker, atenolol, while markedly interferes with that of the liposoluble, without any apparent influence on its anti-hypertensive effect. These findings extend to obese hypertensives the concept that the plasma concentrations of beta-blocking agents are not reliable predictors of their therapeutic effect.  相似文献   
3.
4.
5.
6.
Clinical aspects of pelvic inflammatory disease   总被引:2,自引:0,他引:2  
Pelvic inflammatory disease (PID) is a common and poorly managed condition. Untreated or inadequately treated, it leads to tubal infertility, ectopic pregnancy and chronic pelvic pain. Diagnostic difficulties are compounded by the wide variety of clinical presentations and the insensitivity and poor specificity of laboratory tests. Better recognition of mild and atypical disease needs a high index of suspicion whenever young, sexually active women present with gynaecological symptoms. Laparoscopy supplemented by microbiological tests and fimbrial minibiopsy should be regarded as the diagnostic 'gold standard' for research studies; new studies are required to identify techniques which might reduce under- and over-diagnosis. Early treatment reduces the risk of an adverse effect on fertility. Any therapeutic regimen selected should be effective against the common aetiological agents Chlamydia trachomatis, Neisseria gonorrhoeae, genital mycoplasmas and aerobic and anaerobic bacteria. Since at least 60% of cases of PID can be attributed to infection with a sexually transmitted organism, partner notification forms an essential part of management.   相似文献   
7.
8.
Immunomodulatory effects of two extracts of Panax ginseng C.A. Meyer   总被引:2,自引:0,他引:2  
The effect of Panax ginseng extracts on cell-mediated immune functions in man has been investigated. Three groups, each consisting of twenty healthy volunteers, were treated under conditions of double blindness with capsules containing lactose (Control Group B), with capsules containing 100 mg of aqueous extract of the drug (Group A), and with capsules containing 100 mg of standardized extract of the drug (Group C). All the patients took one capsule every 12 h for 8 weeks. Blood samples were withdrawn before beginning the treatment, at the fourth week and at the eighth week. The immune parameters examined were the following: chemotaxis of PMNs, phagocytosis index (PHI), phagocytosis fraction (PHF), intracellular killing, total lymphocytes (T3), T helper (T4) subset, suppressor cells (T8) subset, blastogenesis of circulating lymphocytes, natural killer-cell activity (NK). Chemotaxis proved to be enhanced (p less than 0.05) already at the fourth week in Group A as well as in Group C; the increase became even more marked (p less than 0.001) at the eight week in subjects belonging to Group C. PHI and PHF proved to be enhanced (p less than 0.05) at the eighth week in subjects of Group A; these increases were found to be higher in subjects of Group C (p less than 0.001) already starting at the fourth week. Intracellular killing was shown to be significantly increased (p less than 0.05) already at the fourth week in Groups A and C; the increase becomes highly significant in both groups (p less than 0.001) at the eighth week; however, a significant increase (p less than 0.05) at the eighth week was also noticed in the placebo group (Group B).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
9.
10.
A double-blind, placebo-controlled study was carried out in 36 patients, aged 30 to 50 years, to evaluate the effectiveness of oral sulodexide in the treatment of chronic venous insufficiency due to idiopathic varices. Patients were allocated at random to receive either oral sulodexide as 2 capsules (each containing 250 lipoproteinolipase releasing units) twice daily or 2 identical placebo capsules twice daily over a period of 45 days. Using strain gauge plethysmographic data, assessments were made of the microcirculatory effects of treatment by calculating the coefficient of capillary filtration from measurements made on both legs of each patient on entry and after 30 and 45 days of treatment. The coefficient is derived from the transmembranous flow values at the occlusive pressures of 60 and 40 mmHg, the difference between the two occlusive pressures examined and a corrective factor to calculate the capillary pressure based on the pressure in the venous circulation. Statistical analysis of the results showed that sulodexide produced a significant mean reduction from baseline values of the coefficient at both the 30 and 45 day examinations whereas the coefficient increased in the placebo group. The difference between the two groups was also statistically significant. These findings suggest that sulodexide has a positive influence on capillary permeability.  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