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   3369259篇
  免费   250107篇
  国内免费   8846篇
耳鼻咽喉   45635篇
儿科学   110132篇
妇产科学   91834篇
基础医学   473927篇
口腔科学   94290篇
临床医学   309029篇
内科学   661904篇
皮肤病学   77213篇
神经病学   277813篇
特种医学   130982篇
外国民族医学   952篇
外科学   503521篇
综合类   72841篇
现状与发展   5篇
一般理论   1291篇
预防医学   266032篇
眼科学   74816篇
药学   246852篇
  11篇
中国医学   6626篇
肿瘤学   182506篇
  2019年   26120篇
  2018年   36881篇
  2017年   28290篇
  2016年   32561篇
  2015年   36729篇
  2014年   50882篇
  2013年   76891篇
  2012年   101667篇
  2011年   107847篇
  2010年   64986篇
  2009年   62221篇
  2008年   100595篇
  2007年   107071篇
  2006年   108910篇
  2005年   104702篇
  2004年   100919篇
  2003年   97328篇
  2002年   93753篇
  2001年   162010篇
  2000年   166440篇
  1999年   140034篇
  1998年   40422篇
  1997年   35950篇
  1996年   36410篇
  1995年   35388篇
  1994年   32654篇
  1993年   30547篇
  1992年   110387篇
  1991年   106584篇
  1990年   103237篇
  1989年   99397篇
  1988年   91312篇
  1987年   89730篇
  1986年   84413篇
  1985年   80667篇
  1984年   60439篇
  1983年   51141篇
  1982年   30405篇
  1981年   27235篇
  1979年   53918篇
  1978年   38313篇
  1977年   32344篇
  1976年   30039篇
  1975年   32043篇
  1974年   38030篇
  1973年   36276篇
  1972年   33885篇
  1971年   31471篇
  1970年   28924篇
  1969年   27522篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
The pharmacokinetics (PK) of moxifloxacin in healthy white New Zealand rabbits was studied following intravenous (IV) and subcutaneous (SC) administration routes as well as a SC long‐acting poloxamer 407 gel formulation (SC‐P407). Moxifloxacin concentrations were determined by high‐performance liquid chromatography assay with fluorescence detection. Mean half‐life for IV, SC and SC‐P407 routes was 2.15, 5.41 and 11.09 h. Clearance value after IV dosing was 0.78 l/kg/h. After SC administration, the mean absolute bioavailability was 117% and the Cmax was 1.61 ± 0.49 mg/l. After SC‐P407 administration, the bioavailability was 44% and the Cmax 1.83 was ±0.62 mg/l. No adverse effects were observed in any of the rabbits following IV, SC and SC‐P407 administration of moxifloxacin. Minimal inhibitory concentrations of moxifloxacin against different strains of Staphylococcus aureus from different european countries were used to compute the main pharmacodynamic (PD) surrogate markers of efficacy. The high tolerability of this SC‐P407 formulation and the favourable PK behaviour such as the long half‐life, acceptable bioavailability and excellent PK–PD ratios achieved indicate that it is likely to be effective in rabbits.  相似文献   
113.
BACKGROUND: The incidence of malignant melanoma of the skin has risen in every part of the world where reliable cancer registration data are found. OBJECTIVE: Our study aims to describe the changing incidence of and survival from invasive cutaneous malignant melanoma in Malta, by analysing the data from the 211 cases that were registered at the Malta National Cancer Registry between 1993 and 2002. RESULTS: The age standardized incidence rates for invasive cutaneous malignant melanoma rose from 3.7 per 100,000 population per year for males and 5.1 for females in the first 5-year period, to 8.0 per 100,000 population per year for males and 5.9 for females in the second 5-year period. In both sexes, numbers of thin (< or = 1.0 mm) invasive melanomas increased significantly between 1993 and 2002; males also registered a significant increase in intermediate-thickness (1.01-4.0 mm) melanomas. The increase in numbers of thin and intermediate-thickness melanomas between the two 5-year periods was greatest in patients aged 60 years and over. The overall absolute 5-year survival rate for the first period was 74% and for the second period 92%. CONCLUSION: Numbers of reported cases of invasive cutaneous malignant melanoma in Malta have more than doubled during the 10-year study period. This is mostly due to a marked rise in the diagnosis of thin melanomas in both sexes, occurring mainly in patients aged 60 years and over. As thin melanomas are of low metastasizing potential, this has resulted in an increase in survival between the two 5-year study periods.  相似文献   
114.
OBJECTIVE: To evaluate the prenatal distribution, associated conditions and outcome of the different types of right aortic arch (RAA) detected in fetal life. METHODS: This was a retrospective review of all cases of RAA detected prenatally between 1998 and 2005 in two tertiary referral centers. RESULTS: In the study period 71 cases of RAA were detected; 26 (37%) had RAA with aberrant left subclavian artery, 23 (32%) had RAA with mirror-image branching, 20 (28%) had RAA of unknown type and two (3%) had double aortic arch. While 20/26 cases with RAA and aberrant left subclavian artery were isolated findings, all 23 cases with RAA and mirror-image branching were associated with cardiac defects, namely tetralogy of Fallot (43%) or pulmonary atresia with ventricular septal defect (22%). Of the 20 cases with RAA, 19 of unknown type were associated with heterotaxy syndromes and had additional cardiac malformations and ambiguities of the situs. The two cases with DAA were isolated findings. Seven cases in our series (10%) had a microdeletion 22q11 and these were significantly associated with extracardiac malformations. The outcome in our series depended solely on the associated cardiac and extracardiac malformations, with the exception of one infant with isolated DAA, in whom a surgical correction was warranted. CONCLUSIONS: RAA detected in fetal life is associated frequently with other cardiac/non-cardiac malformations, heterotaxy syndromes and microdeletions 22q11. The associated conditions vary depending on the branching type of the brachiocephalic vessels and the presence of extracardiac malformations.  相似文献   
115.
Southgate  M. Therese 《JAMA》2006,296(13):1564
  相似文献   
116.
Volume and profile of alcohol consumption among students and classmates as predictors of aggression and victimization: a multilevel analysis among Swiss adolescents

Objective:  

To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels.  相似文献   
117.
118.
119.
120.
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