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   35158篇
  免费   1721篇
  国内免费   77篇
耳鼻咽喉   488篇
儿科学   1324篇
妇产科学   579篇
基础医学   4274篇
口腔科学   853篇
临床医学   2344篇
内科学   9252篇
皮肤病学   1211篇
神经病学   3127篇
特种医学   1004篇
外科学   5205篇
综合类   161篇
一般理论   6篇
预防医学   2875篇
眼科学   689篇
药学   1789篇
中国医学   115篇
肿瘤学   1660篇
  2023年   266篇
  2022年   283篇
  2021年   993篇
  2020年   447篇
  2019年   951篇
  2018年   1424篇
  2017年   756篇
  2016年   762篇
  2015年   837篇
  2014年   986篇
  2013年   1495篇
  2012年   2494篇
  2011年   2651篇
  2010年   1353篇
  2009年   1092篇
  2008年   2158篇
  2007年   2230篇
  2006年   2173篇
  2005年   2066篇
  2004年   1908篇
  2003年   1679篇
  2002年   1692篇
  2001年   1072篇
  2000年   1294篇
  1999年   935篇
  1998年   179篇
  1997年   129篇
  1996年   135篇
  1995年   90篇
  1994年   71篇
  1993年   56篇
  1992年   334篇
  1991年   251篇
  1990年   261篇
  1989年   186篇
  1988年   139篇
  1987年   127篇
  1986年   134篇
  1985年   105篇
  1984年   83篇
  1983年   52篇
  1982年   39篇
  1979年   36篇
  1976年   34篇
  1974年   57篇
  1973年   60篇
  1972年   42篇
  1971年   39篇
  1970年   42篇
  1969年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
BACKGROUND: The mainstay of treatment for pemphigus is systemic corticosteroids. Different adjuvants have been used to reduce side-effects of long-term corticotherapy. Gold is an anti-inflammatory drug used in autoimmune diseases, whose use has waned with the advent of new immunosuppressive agents. OBJECTIVE: To study the outcome of the use of intramuscular gold treatment of pemphigus vulgaris refractory to previous therapies. METHODS: Thirteen patients with pemphigus vulgaris who had failed to respond to several prior therapies were treated with aurothiomalate, as a steroid-sparing agent. Patients were monitored to assess disease activity and gold toxicity. RESULTS: Seven patients achieved complete remission. Four patients were able to taper prednisone doses, although pemphigus flared when prednisone was discontinued or reduced. Toxicity was observed in the other two patients. CONCLUSIONS: In 53.4% of the patients, the use of chrysotherapy resulted in the complete clearing of the disease, discontinuation of all systemic therapies and induced a long-term clinical remission. Prednisone doses were able to be reduced in the remaining 46.6%. Any side-effects were reversible with drug discontinuation. Gold therapy showed efficacy as a secondary line treatment in refractory pemphigus vulgaris.  相似文献   
62.
Resumen La técnica del cultivo celular es la que ha permitido conocer el comportamientoin vitro de las células cancerosas. En esta revisión pretendemos introducir las peculiaridades básicas del cultivo celular, referido especialmente a líneas cancerosas mamarias, relacionar el origen de las líneas celulares más utilizadas en la investigación de este cáncer, mencionar las técnicas de laboratorio que pueden aplicarse sobre estos cultivos y ejemplificar la utilidad de las mismas, tomando como modelo diversos trabajos que estudian los efectos del factor de crecimiento epidérmico sobre líneas celulares hormonoindependientes de cáncer de mama.   相似文献   
63.
64.
65.
66.
Penbutolol is a beta-adrenoceptor antagonist that is extensively bound to alpha 1-acid glycoprotein (alpha 1-AGP), a protein that increases in inflammatory diseases thereby binding more drug in such conditions. Changes in serum binding can lead to modifications in the pharmacokinetics and pharmacodynamics of a drug, therefore, the central effect (as the anticonvulsant response) and brain uptake of penbutolol given intravenously to mice with experimental inflammation have been measured. A significant decrease of the central effect of penbutolol and its brain uptake was seen in diseased when compared with control animals (P less than 0.01). A parallel decrease in free fraction of penbutolol in diseased vs normal animals was detected. These results suggest that there is an increase in serum binding of basic drugs related to increments in alpha 1-AGP concentration, which reduces their central pharmacological effect.  相似文献   
67.
A total of 163 Hysterothylacium aduncum specimens, obtained from two gadoids and one percid, were studied by electrophoresis of the enzymes glucose phosphate isomerase and phosphoglucomutase. The two loci deviated significantly from the Hardy-Weinberg equilibrium, both when considering all specimens and when distinguishing the hosts. This could suggest that there is no single species in either case. Received: 16 June 1997 / Accepted: 11 July 1997  相似文献   
68.
The model of biliary tract infection induced in rats given suspension of E. coli into the bile duct is described. To prevent leakage of microorganisms after the administration, a temporary ligation of the bile duct followed. Contemporary groups of sham-operated and control rats (given saline by intrabiliary injection) were compared to assess the significance of the changes. The effect of biliary infection was concentration dependent. If 0.1 ml of the concentration containing 10(2), 10(3) and 10(6) colony-forming units/ml was injected, the mortality of rats reached 8%, 57% and 65%, respectively within 24 h. Blood and bile cultures from all dead animals grew E. coli. To evaluate the effect of chronic biliary infection, the concentration of 10(2) colony-forming units/ml was used. Serum concentrations of total and conjugated bilirubin, cholesterol and creatinine, activities of S-alanine-aminotransferase, S-aspartate-aminotransferase, alkaline phosphatase, the count of leucocytes in blood, total body weight with weight of the liver were investigated on days 1, 4 and 12 after the treatment. The results showed: an increase in leucocytes (21 +/- 4.2 10(9)/l, p less than 0.02 vs control animals) on day 4, an augmentation of serum cholesterol on day 1, (2.1 +/- 0.9 mmol/l, p less than 0.02 vs control animals), the presence of E. coli in blood on day 1 and its persistence in the bile on days 1, 4 and 12. Except the bile, all of the other symptoms were reversible by day 12.  相似文献   
69.
We reviewed 488 twin pregnancies that resulted in the birth of neonates weighing 1000 g or more. Complications were present in 56.7% of all pregnancies; most common were threat of premature labor (17.4%) and preeclampsia (14.5%). Perinatal mortality was 31.8 per thousand. Eighty percent of neonatal deaths in twin pregnancies involved newborns weighing less than 2000 g. Twin pregnancies are high risk pregnancies and benefit from early diagnosis, prevention and treatment of the threat of premature birth.  相似文献   
70.
A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent201T1 rest-injection and99mTc-tetrofosmin. baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of99mTc-tetrofosmin at baseline correlated with that of 201T1 (r=0.82,P <0.001). On baseline99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peal. activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in99mTc-tetrofosmin uptake from 40%±9% to 57%±9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on201Tl studies, but 20 segments that were non-viable on99mTc-tetrofosmin. studies were viable on201Tl studies. Using a threshold value of >40% of peak activity, only seven segments remained non-viable on99mTc-tetrofosmin studies. Overall agreement between99mTc-tetrofosmin with nitrates and201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with99mTc-tetrofosmin. was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.  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