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   67771篇
  免费   3692篇
  国内免费   148篇
耳鼻咽喉   866篇
儿科学   1501篇
妇产科学   1369篇
基础医学   9019篇
口腔科学   2605篇
临床医学   5198篇
内科学   16906篇
皮肤病学   1658篇
神经病学   5998篇
特种医学   1540篇
外科学   9129篇
综合类   285篇
一般理论   26篇
预防医学   5854篇
眼科学   1293篇
药学   4451篇
中国医学   252篇
肿瘤学   3661篇
  2024年   48篇
  2023年   451篇
  2022年   208篇
  2021年   1123篇
  2020年   655篇
  2019年   1184篇
  2018年   2088篇
  2017年   1251篇
  2016年   1334篇
  2015年   2032篇
  2014年   2069篇
  2013年   3010篇
  2012年   5928篇
  2011年   5808篇
  2010年   2647篇
  2009年   1951篇
  2008年   4918篇
  2007年   5108篇
  2006年   5293篇
  2005年   4992篇
  2004年   4504篇
  2003年   4035篇
  2002年   3921篇
  2001年   1567篇
  2000年   2078篇
  1999年   997篇
  1998年   209篇
  1997年   149篇
  1996年   155篇
  1995年   142篇
  1994年   109篇
  1993年   107篇
  1992年   120篇
  1991年   110篇
  1990年   72篇
  1989年   76篇
  1988年   54篇
  1987年   52篇
  1986年   66篇
  1985年   73篇
  1984年   94篇
  1983年   59篇
  1982年   77篇
  1981年   68篇
  1980年   73篇
  1979年   43篇
  1978年   38篇
  1977年   37篇
  1976年   34篇
  1974年   33篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
Ischemic stroke occurs in 0.2-0.4% of patients undergoing left heart catheterization, and is responsible for 5-10% of the mortality associated with the procedure. The main predisposing factors for this complication are female gender, complex atherosclerotic plaques in the ascending aorta, and peripheral arterial disease. The possibility of timely intervention with reperfusion therapy supports close clinical monitoring during the immediate post-catheterization period. The cardiologist should be familiar with the various types of stroke reperfusion therapy and its indications according to the time interval between catheterization and the stroke. The decision should be discussed with neurology and neuroradiology.  相似文献   
103.
104.
The modulation of extracellular 5-hydroxytryptamine (5-HT) in the central nucleus of the amygdala (CeA) by 5-HT1A receptors was studied by intracerebral microdialysis in awake and freely moving rats. Local administration of 1 μM tetrodotoxin (TTX), 60 mM K+ and perfusion with Ca2+-free Ringer containing EGTA confirmed that the major part of dialysate 5-HT levels from the CeA is of neuronal origin. Administration of 300 nM of RU 24969, a 5-HT1B receptor agonist, through the probe into the CeA decreased dialysate 5-HT levels to 67.2% of the baseline value. Systemic administration of the 5-HT1A receptor agonists 8-OH-DPAT and flesinoxan dose-dependently decreased 5-HT levels in the CeA. The effect of 0.3 mg/kg of flesinoxan could be completely antagonized by systemic administration of 0.05 mg/kg WAY 100635, a 5-HT1A receptor antagonist. WAY 100635 alone had only minimal effects at this dose. These data show that a major part of the extracellular 5-HT in the CeA stems from 5-HT neurons and that the amount of 5-HT released into this brain region can be modulated by 5-HT1A receptors. Received: 11 September 1996 / Accepted: 25 November 1996  相似文献   
105.
106.
BACKGROUND AND OBJECTIVES: The aim of this study was to compare in a prospective nonrandomized study, the efficacy of 2 methods of administering methotrexate (MTX) in the treatment of ectopic pregnancy (EP): transvaginal injection under sonographic control or intramuscular injection (IM). METHODS: Patients with EP who met specific inclusion criteria for medical treatment were treated with MTX: 63 patients (group 1) were treated by IM and 47 patients (group 2) by transvaginal local injection. In group 1, 50 mg/m2 of MTX was injected intramuscularly; in group 2, transvaginal injection of 1 mg/kg of MTX was injected into the ectopic sac under sonographic control. When an additional dose of MTX was required, it was administrated IM at the dosage of 50 mg/m2 in both groups. RESULTS: The overall success rate, defined by a posttreatment normal hCG level (< 10 mUI/mL) was 71.4% in group 1 versus 91.5% in group 2 (P < 0.01); for patients with hCG levels < 2000 mUI/mL, 83% and 96%, respectively (not significant); for patients with hCG > or = 2000 mUI/mL, 37.5% and 86.4%, respectively (P < 0.01). CONCLUSION: In the medical treatment of EP, the efficacy of MTX is greater when administered by local transvaginal injection than by IM injection. We propose local treatment every time EP can be punctured, especially when hCG levels are > or = 2000 mUI/mL.  相似文献   
107.
108.
OBJECTIVE: Respiratory scleroma (RS) is a progressive, chronic, granulomatous disease caused by Klebsiella rhinoscleromatis. There is only one report of RS association with HLA-DQ3. In this study, molecular association of HLA class II and RS was determined. STUDY DESIGN AND SETTING: Nine RS patients and 163 healthy controls were compared. DQA1, DQB1, and DRB1 loci were typed. RESULTS: Statistical analysis demonstrated association between DQB1*0301 and susceptibility to RS (P(c) = 0.004). Haplotype analysis showed an association of DQA1*03011-DQB1*0301 (P = 1.21E-19) and DRB1*0407-DQA1*03011-DQB1*0301 (P = 0.0002). CONCLUSIONS: Results established that DQA1*03011-DQB1*0301 haplotype is a strong risk factor for development of RS.  相似文献   
109.
OBJECTIVE: To investigate the feasibility of intracoronary application of endothelial progenitor cells and the subsequent distribution within the heart. METHODS: Endothelial progenitors cells (EPCs) cultured from rat bone marrow were identified by double-positive staining with Dil-Ac-LDL and BS1-lectin. Twenty-four hours before cell transplantation, EPCs were labeled with 5-bromo-2'-deoxyuridine (BrdU). Cells (5 x 10(5) in 250-microl medium) were injected into healthy rats, either as intracoronary application (n=11) or as intramyocardial injection (n = 6). At 15 min or 3 days posttransplantation, hearts as well as other organs (lung, liver, kidney, and spleen) were collected and processed for subsequent BrdU immunohistochemistry. The number of BrdU-positive cells per tissue area was counted. RESULTS: Compared to intramyocardial injection, intracoronary administration resulted in more than twice as much positive cells in the heart (P < .05), with no local differences within the heart. Whereas after 15 min, EPCs were equally distributed in all examined organs (except for the spleen), cells that were still present after 3 days, approximately 10%, were selectively restricted to the heart. CONCLUSIONS: Our data indicate that the intracoronary application provides a promising technique for EPC transplantation in the rat heart.  相似文献   
110.
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