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   707297篇
  免费   48944篇
  国内免费   1308篇
耳鼻咽喉   9204篇
儿科学   23335篇
妇产科学   17667篇
基础医学   110472篇
口腔科学   19989篇
临床医学   63859篇
内科学   134652篇
皮肤病学   16200篇
神经病学   49481篇
特种医学   25773篇
外国民族医学   77篇
外科学   104728篇
综合类   14856篇
现状与发展   2篇
一般理论   160篇
预防医学   51457篇
眼科学   16375篇
药学   54132篇
  3篇
中国医学   2366篇
肿瘤学   42761篇
  2021年   5509篇
  2018年   7924篇
  2017年   6161篇
  2016年   6858篇
  2015年   7597篇
  2014年   10312篇
  2013年   15451篇
  2012年   20611篇
  2011年   21593篇
  2010年   12772篇
  2009年   11993篇
  2008年   20051篇
  2007年   21573篇
  2006年   21944篇
  2005年   20476篇
  2004年   20008篇
  2003年   18963篇
  2002年   18469篇
  2001年   36353篇
  2000年   36912篇
  1999年   30394篇
  1998年   7889篇
  1997年   6671篇
  1996年   6985篇
  1995年   6640篇
  1994年   6102篇
  1993年   5593篇
  1992年   22975篇
  1991年   22940篇
  1990年   22318篇
  1989年   22091篇
  1988年   20060篇
  1987年   19441篇
  1986年   18477篇
  1985年   17312篇
  1984年   12705篇
  1983年   10747篇
  1982年   5925篇
  1979年   11530篇
  1978年   8136篇
  1977年   6839篇
  1976年   6608篇
  1975年   7276篇
  1974年   8508篇
  1973年   8150篇
  1972年   7665篇
  1971年   7130篇
  1970年   6883篇
  1969年   6310篇
  1968年   5783篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
Carbohydrate metabolism was evaluated by fasting and postprandial glucose, insulin, and hemoglobin (Hb)A1c levels in children with chronic renal insufficiency and various other growth disorders treated with growth hormone. Mean fasting and postprandial glucose remained unchanged throughout the 5-year study period in all four study groups. Median fasting insulin levels rose from lownormal levels into the normal range after 5 years of growth hormone. Average fasting insulin level after 5 years was 10 mU/l. Median postprandial insulin values also rose, yet remained within the normal range at the 5-year mark. Mean Hb A1c levels remained within low to middle end of the normal range in the patients with growth hormone deficiency, Turner syndrome, and idiopathic short stature. Mean Hb A1c levels at the 5 years were slightly elevated to 6.3% for the patients with chronic renal insufficiency.  相似文献   
994.
995.
In the present study, the possibility that cyclophosphamide or a cyclophosphamide metabolite may be accelerating the clearance of triiodothyronine has been examined. Following administration of exogenous triiodothyronine to saline-and cyclophosphamide-treated rats, the area under the plasma-concentration time curve (AUC), apparent clearance (CLapp) and half-life of triiodothyronine were measured. AUC (34.43 ± 12.34 compared with 33.32 ± 9.92 nmol hL?1), CLapp (36.30 ± 12.89 compared with 37.51 ± 11.16 mLh?1) and half-life (7.50 ± 1.39 compared with 6.40 ± 0.96 h) were not significantly different in the control rats compared with the cyclophosphamide-treated rats. As cyclophosphamide does not appear to alter the elimination of triiodothyronine, it is likely that cyclophosphamide or a cyclophosphamide metabolite is acting at the hypothalamo-pituitary axis, reducing the synthesis or release of thyroid stimulating hormone and consequently decreasing the levels of triiodothyronine and thyroxine.  相似文献   
996.
We have assembled a panel of monochromosomal somatic cell hybrids for use in gene mapping. DNA from each individual hybrid was used as a probe on normal human metaphases to identify the human chromosome and any fragments by reverse painting. To test the efficiency of the panel PCR amplification of DNA from the monochromosomal somatic cell hybrid panel was used in combination with human specific oligonucleotide primers to assign α-catenin (CTNNA1) and p21/WAFl to chromosomes 5 and 6 respectively. These genes were localized further using hybrids containing specific translocations to 5qll-qter and 6p21 respectively. We also developed primers to enable us to assign 17 ESTs sequenced by the HGMP Resource Centre. The hybrid panel was developed with support of the UK HGMP and the DNA is available to all registered users.  相似文献   
997.
1. Vasodepressor responses to intravenous (i.v.) injection of bradykinin (BK) and des-Arg9-BK, a selective B1 kinin receptor agonist, were characterized following i.v. pretreatment with selective B1 ([Leu8]-des-Arg9-BK) and B2 (Hoe 140) kinin receptor antagonists in anaesthetized dogs. 2. Des-Arg9-BK (0.05-3.3 nmol kg-1) produced dose-dependent decreases in mean arterial blood pressure with a ED50 0.4 nmol kg-1. The vasodepressor effects evoked by des-Arg9-BK (0.6 nmol kg-1) and BK (0.2 nmol kg-1) were greater after i.v. and i.a. injections, respectively. 3. The vasodepressor response to BK (0.6 nmol kg-1) but not to des-Arg9-BK (0.6 nmol kg-1) was significantly (P < 0.001) blocked by pretreatment with the B2 receptor antagonist, Hoe 140. 4. The vasodepressor response to des-Arg9-BK (0.6 nmol kg-1) but not to BK (0.6 nmol kg-1) was significantly (P < 0.001) reduced by pretreatment with the selective B1 receptor antagonist, [Leu8]-des-Arg9-BK. Although both B1 and B2 receptor antagonists caused a transient fall in blood pressure, their inhibitory action was unlikely to be related to a desensitization mechanism. 5. Inhibition of prostaglandin synthesis with indomethacin prevented the vasodepressor response induced by arachidonic acid (1 mg kg-1, i.v.) but not that to BK or des-Arg9-BK (0.6 nmol kg-1). 6. These results suggest, firstly, that the vasodepressor responses to i.v. BK and des-Arg9-BK are mediated by the activation of B2 and B1 receptors, respectively; secondly, that prostaglandins are not involved in the vasodepressor responses to kinins.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
998.
In a group of 182 patients who underwent surgical treatment for aortoiliac occlusions 172 had to be subjected to intraoperative distal angiography. The operative tactics in this case was determined by the degree of affection of the peripheral vessels and the character of collateral circulation, which were appraised from the findings of the operative angiograms. According to this, all patients were divided into 4 groups. Two patients developed complications linked with faulty appraisal of the drainage paths.  相似文献   
999.
1000.
The authors discuss the results of application of proteinase preparations immobilized on a water soluble carrier (Immozymase) and a water insoluble carrier (Profezyme) in the management of ++pyo-necrotic processes of various etiology and localization in 1,059 patients. The wounds were cleansed 1.5-2 times quicker than with the traditional methods of treatment. Immobilized proteinases possessing a prolonged therapeutic effect were found to stimulate the regeneration process. The authors believe the use of Immozymase to be promising in the treatment of purulent foci which are drained with difficulty and in intracavitary administration for treating purulent processes in the thoracic or abdominal cavity.  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