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   13987篇
  免费   1143篇
  国内免费   41篇
耳鼻咽喉   124篇
儿科学   342篇
妇产科学   343篇
基础医学   1990篇
口腔科学   356篇
临床医学   1493篇
内科学   2905篇
皮肤病学   250篇
神经病学   1052篇
特种医学   642篇
外国民族医学   17篇
外科学   1819篇
综合类   135篇
一般理论   6篇
预防医学   1391篇
眼科学   185篇
药学   938篇
中国医学   20篇
肿瘤学   1163篇
  2022年   80篇
  2021年   180篇
  2020年   137篇
  2019年   204篇
  2018年   265篇
  2017年   169篇
  2016年   244篇
  2015年   260篇
  2014年   341篇
  2013年   466篇
  2012年   645篇
  2011年   636篇
  2010年   365篇
  2009年   368篇
  2008年   600篇
  2007年   594篇
  2006年   595篇
  2005年   578篇
  2004年   545篇
  2003年   560篇
  2002年   529篇
  2001年   509篇
  2000年   546篇
  1999年   489篇
  1998年   195篇
  1997年   159篇
  1996年   154篇
  1995年   131篇
  1994年   114篇
  1993年   118篇
  1992年   358篇
  1991年   310篇
  1990年   294篇
  1989年   255篇
  1988年   267篇
  1987年   226篇
  1986年   255篇
  1985年   230篇
  1984年   187篇
  1983年   174篇
  1982年   97篇
  1981年   94篇
  1980年   99篇
  1979年   154篇
  1978年   112篇
  1977年   96篇
  1975年   85篇
  1974年   107篇
  1973年   116篇
  1971年   86篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Cancer Chemotherapy and Pharmacology - Addition of solid doxorubicin or solutions to pre-formed liposomes proved to be the optimal method for incorporating the drug into liposomes whilst...  相似文献   
3.
4.
5.
Peters  Etete J. 《JAMA》2005,293(4):498-499
  相似文献   
6.
7.
Previous studies have shown that maternal stress modifies 5-hydroxytryptamine (5-HT) receptor binding in several brain regions of the adult offspring and alters the intensity of the behavioral responses to 5-HT receptor agonists. We now report that the same stress, crowding combined with daily saline injections during the final week of pregnancy, elevates maternal plasma free tryptophan level without significantly affecting total tryptophan. The increased maternal plasma tryptophan was associated with significantly increased fetal brain levels of tryptophan, 5-HT and 5-hydroxyindoleacetic acid. These increases were maintained after birth until at least postnatal day 10. Since 5-HT is recognised as having a role in the control of neuron development during the perinatal period, we suggest that the stress-induced increase in fetal brain 5-HT synthesis may play a part in the mechanisms by which prenatal stress alters adult behavior.  相似文献   
8.
BACKGROUND: Sore throat is a common symptom presented to general practitioners (GPs), and there remains controversy about the appropriate use of antibiotics. AIM: To compare, in a randomized controlled trial, the effectiveness of penicillin, cefixime and placebo on symptom resolution in patients presenting with a sore throat in general practice. METHOD: Twenty-two GPs in Avon recruited 154 patients, aged 16-60 years, presenting to their GP with a sore throat, and for whom the GP would normally prescribe an antibiotic. Patients were randomized to one of three groups: penicillin V 250 mg four times a day; cefixime 200 mg daily; and placebo. Each was prescribed for five days. The main outcome measures were a diary of symptom resolution over seven days and eradication of group A beta-haemolytic streptococcus (GABHS). RESULTS: Of the 103 (67%) patients who completed symptom diaries, 40 were allocated to receive penicillin, 29 cefixime and 34 placebo. In the analysis including all patients, symptom resolution was greater by day 3 in the cefixime group than in the placebo group. Penicillin did not improve symptom resolution by day 3 compared with placebo, and cefixime was not statistically significantly different from penicillin. There were significant differences in the proportion of patients using analgesia at day 3, with the proportion being lowest in the cefixime group. The results for the subgroup of patients without GABHS were similar to those for all patients; in particular, the only statistically significant difference was between cefixime and placebo. Although numbers were too small for statistical significance, among patients with GABHS the effects of penicillin and cefixime were similarly raised in relation to placebo. CONCLUSION: Compared with placebo, cefixime can improve the rate of resolution of symptoms in patients with a sore throat who are selected for antibiotic treatment by their GP. The unexpected finding that cefixime was of benefit compared with placebo for patients without GABHS suggests that bacteria other than GABHS may be important in the pathogenesis of sore throat.  相似文献   
9.
10.
Summary Macrophage subtypes were detected in cryostat sections of biopsies from patients with chronic osteomyelitis, acute joint infections and normal bone marrow, using monoclonal antibodies against different macrophage populations. The resident macrophage subtype 25F9, the glucocorticoid-inducible macrophage RM 3/1 and the inflammatory type 27E10 were found in abundance in acute infections. They were also present in tissue sections of uninflamed bone marrow. By contrast, in about 50% of the biopsies from patients with chronic osteomyelitis a reduced number of macrophage subtypes, or even the lack of one or more macrophage subpopulations was found. The unusual absence of macrophage phenotypes seems to be restricted to the area of osteomyelitis because in the tissues of inflamed sinuses in these patients, the macrophage subtypes were present. These findings suggest a disturbance at the level of the macrophages which may contribute to the persistence of the inflammatory process in osteomyelitis.
Résumé L'utilisation d'anticorps monoclonaux contre différentes sous-populations de macrophages a permis de mettre en évidence, à l'examen de coupes cryostatiques, des sous-types de macrophages. Ces derniers ont été retrouvés dans les moelles osseuses normales comme dans les biopsies provenant de malades atteints d'ostéomyélite chronique et d'arthrite aiguë. Le sous-type résident 25F9, le macrophage glycocorticoïde inductible RM 3/1 et le sous-type inflammatoire 27E10 ont été trouvés en abondance dans les infections aiguës. Ils étaient également présents dans des coupes de moelle osseuse non inflammatoire. Inversement dans près de 50% des cas le nombre de ces sous-populations était considérablement diminué, et même certaines d'entre elles avaient complétement disparu, sur les pièces biopsiques d'ostéomyélite chronique. L'absence inhabituelle de certains types de macrophages semble être limitée à la zone ostéitique car on les retrouve dans le tissu inflammatoire des fistules. Cette étude semble montrer que l'atteinte de ces sous-populations serait responsable de la chronicité de l'ostéomyélite.
  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