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   3773篇
  免费   368篇
  国内免费   47篇
耳鼻咽喉   100篇
儿科学   120篇
妇产科学   66篇
基础医学   401篇
口腔科学   49篇
临床医学   318篇
内科学   753篇
皮肤病学   251篇
神经病学   203篇
特种医学   193篇
外科学   557篇
综合类   320篇
一般理论   6篇
预防医学   212篇
眼科学   79篇
药学   224篇
  1篇
中国医学   72篇
肿瘤学   263篇
  2024年   5篇
  2023年   61篇
  2022年   44篇
  2021年   150篇
  2020年   124篇
  2019年   117篇
  2018年   119篇
  2017年   97篇
  2016年   114篇
  2015年   128篇
  2014年   157篇
  2013年   159篇
  2012年   213篇
  2011年   242篇
  2010年   115篇
  2009年   121篇
  2008年   168篇
  2007年   187篇
  2006年   211篇
  2005年   160篇
  2004年   155篇
  2003年   148篇
  2002年   143篇
  2001年   121篇
  2000年   118篇
  1999年   107篇
  1998年   37篇
  1997年   38篇
  1996年   35篇
  1995年   31篇
  1994年   47篇
  1993年   40篇
  1992年   59篇
  1991年   46篇
  1990年   38篇
  1989年   43篇
  1988年   38篇
  1987年   51篇
  1986年   42篇
  1985年   35篇
  1984年   24篇
  1983年   13篇
  1982年   10篇
  1980年   5篇
  1979年   14篇
  1978年   10篇
  1974年   7篇
  1973年   8篇
  1968年   4篇
  1967年   6篇
排序方式: 共有4188条查询结果,搜索用时 31 毫秒
21.
Hepatitis B infection in prostitutes   总被引:1,自引:0,他引:1  
The prevalence of HBV markers in prostitutes is known to be higher than that of the normal population of similar age range in previous studies. This study showed a significant correlation between the duration of prostitution and the prevalence of HBV antibodies amongst the prostitutes. The prevalence of HBV antibodies doubled after the first year of prostitution. A two-year follow-up study of these prostitutes showed that 37% of HBsAg positive prostitutes lost the HBsAg. The seroconversion rate of HBsAg negative prostitutes was 10% during this two-year period. Early immunization against HBV infection should be considered in this high risk group in view of these findings.  相似文献   
22.
Goh  B.K.  AngP.  Wu  Y.J.  Goh  C.L.  潘敏 《世界核心医学期刊文摘》2006,2(8):34-35
背景:大多数已报道的基底细胞癌(BCCs)的特征主要是依据高加索患者。而关于亚洲人中不完全切除BCCs的特征少见报道。目的:本研究调查了新加坡亚洲居民的BCCs特征,并对常规外科切除术后完全切除与不完全切除肿瘤进行了比较。患者和方法:收集1991--1995年间在国家皮肤病中心行肿瘤切除术的原发性BCC患者的病历进行回顾性研究。结果:166例BCC患者(男女比0.95;平均年龄70.9岁)的185个组织病检确诊的BCCs记录在案。发病最高比例(27.1%)在8l~90岁年龄组。与普查资料相比,华人BCCs患者的比例明显增高(P〈0.001)。肿瘤平均直径为12.0mm,且大多数(84.3%)位于头颈部。28处(15.1%)皮损被不完全切除,多位于鼻部及鼻唇沟。不完全切除的基底细胞癌较完全切除的基底细胞癌更多发生于面中部及躯干部(P=0.003),但与肿瘤大小、肿瘤持续时间、患者年龄、种族及性别无显著相关。平均随访74个月,  相似文献   
23.
The clinical importance of intermittent intracranial pressure (ICP) elevations during sleep in hydrocephalic children is unclear. Eight studies of continuous ICP monitoring with simultaneous cerebral blood-flow velocity (CBFV) measurements were recorded during sleep in seven hydrocephalic children aged between one and 10 years. ICP was measured directly through a frontal reservoir. There were two main patterns of CBFV change in response to raised ICP: a progressive decrease in mean flow velocity and increase in resistance index, suggesting impaired haemodynamic compensation to ICP elevation due to reduced circulatory reserve in patients with limited intracranial compliance; and an increase in mean flow velocity with raised ICP, suggesting that appropriate haemodynamic compensation with increased blood-flow can occur to maintain adequate cerebral perfusion in those with sufficient circulatory reserve. Simultaneous CBFV and ICP measurements may help to identify those with reduced circulatory reserve who are at greater risk of ischaemic insult from episodic increases in ICP.  相似文献   
24.
25.
我国各省药品经营(零售)许可管理部分规定的比较   总被引:1,自引:0,他引:1  
李艳秋  叶桦  王怡慧 《中国药事》2006,20(8):451-453
本文收集并比较了全国各省有关药品零售企业的开办规定。结果表明,各省在药品零售企业药学专业人员配备、药房合理布局、仓库设置等方面的要求各具特色,零售药房的监管需进一步完善。  相似文献   
26.
27.
28.
Perforation of the large bowel during colonoscopy in Singapore   总被引:1,自引:0,他引:1  
The management of seven patients with colonoscopy-related perforations is described. This study demonstrates the need for an early laparotomy. A high index of suspicion is required to reach an early diagnosis. Patients with no preexisting medical problems who underwent early surgery recovered with little morbidity. In elderly patients (greater than 75 years), colonoscopic perforation can be fatal. Endoscopy should be performed with special care in such patients.  相似文献   
29.
Previously established radiometric techniques were used to assess the effectiveness of combined antimicrobial drug-inhibitory drug (drug-inhibitor) treatment on two clinical isolates of the Mycobacterium avium complex representing three colony variants: smooth opaque (dome) (SmO), smooth transparent (SmT), and rough (Rg). All variants were identified as members of the M. avium complex; however, only the SmT colony type of strain 373 possessed characteristic serovar-specific glycopeptidolipid (GPL) antigens. MICs, determined radiometrically, of drugs with the potential to inhibit the biosynthesis of GPL antigens or other cell envelope constituents were similar for all strains. These drugs included cerulenin, N-carbamyl-DL-phenylalanine, N-carbamyl-L-isoleucine, trans-cinnamic acid, ethambutol, 1-fluoro-1-deoxy-beta-D-glucose, 2-deoxy-D-glucose, and m-fluoro-phenylalanine. The MICs of the antimicrobial drugs amikacin, sparfloxacin, and clarithromycin varied, but overall the MICs for the SmO variant were the lowest. Radiometric assessment of drug-inhibitor combinations by using established x/y determinations revealed enhanced activity when either ethambutol or cerulenin were used in combination with all antimicrobial agents for all variants except the Rg variant of strain 424, for which ethambutol was not effective. Enhanced activity with amino acid analogs was observed with the Rg colony variants of strains 373 and 424. Two potential sites for drug targeting were identified: fatty acid synthesis, for all strains assayed, and peptide biosynthesis, particularly for Rg colony variants that possess previously identified phenylalanine-containing lipopeptides as potential targets for future drug development.  相似文献   
30.
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