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   8267篇
  免费   671篇
  国内免费   11篇
耳鼻咽喉   170篇
儿科学   373篇
妇产科学   217篇
基础医学   936篇
口腔科学   227篇
临床医学   650篇
内科学   2135篇
皮肤病学   258篇
神经病学   565篇
特种医学   258篇
外科学   1458篇
综合类   26篇
一般理论   2篇
预防医学   711篇
眼科学   193篇
药学   385篇
中国医学   34篇
肿瘤学   351篇
  2023年   35篇
  2022年   78篇
  2021年   224篇
  2020年   124篇
  2019年   284篇
  2018年   276篇
  2017年   199篇
  2016年   209篇
  2015年   212篇
  2014年   299篇
  2013年   379篇
  2012年   431篇
  2011年   512篇
  2010年   347篇
  2009年   258篇
  2008年   396篇
  2007年   446篇
  2006年   457篇
  2005年   423篇
  2004年   384篇
  2003年   369篇
  2002年   357篇
  2001年   304篇
  2000年   356篇
  1999年   253篇
  1998年   66篇
  1997年   52篇
  1996年   55篇
  1995年   47篇
  1994年   38篇
  1993年   35篇
  1992年   133篇
  1991年   115篇
  1990年   102篇
  1989年   98篇
  1988年   55篇
  1987年   54篇
  1986年   47篇
  1985年   50篇
  1984年   34篇
  1983年   29篇
  1979年   27篇
  1975年   20篇
  1974年   18篇
  1973年   24篇
  1972年   22篇
  1971年   21篇
  1970年   18篇
  1969年   22篇
  1968年   19篇
排序方式: 共有8949条查询结果,搜索用时 15 毫秒
1.
2.
SETTING: Tuberculosis (TB) cases reported from nine districts of Madrid, where the percentage of immigrant population varied from 1.9% in 1996 to 12.2% in 2003. OBJECTIVE: To describe the trends in TB incidence from 1994 to 2003. DESIGN: Observational study. RESULTS: Between 1994-1995 and 2002-2003, the TB rate decreased from 48.5 (95% CI 45.8-51.1) to 23.3 per 100000 population (95% CI 21.5-25.1) (P < 0.001). The percentage of TB cases co-infected with HIV decreased from 55.9% in 1994 to 14.3% in 2003 (P < 0.001), whereas TB cases in foreigners increased from 2.6% in 1994 to 33.7% in 2003 (P < 0.001). CONCLUSION: Although the TB rates showed a marked decrease in the study period, the increasing impact of immigration contributed to slowing down the trend.  相似文献   
3.
Prisons and prison inmates present important targets for HIV/AIDS prevention interventions. Inmates often have histories of high-risk behavior that place them in danger of contracting HIV/AIDS, and rates of HIV/AIDS tend to be much higher in this population. The goal of this study was to assess the effectiveness of a prison-based HIV/AIDS intervention to change attitudes toward HIV prevention, norms supporting HIV prevention, perceived behavioral control (i.e., self-efficacy) for HIV prevention behaviors, and intentions to engage in HIV prevention behaviors postrelease. The intervention also had the goal of encouraging inmates to become HIV/AIDS peer educators. The intervention appeared most successful at influencing beliefs and behaviors related to peer education and somewhat successful at influencing beliefs and intentions related to condom use. Analyses also showed some significant differences in effectiveness by race/ethnicity. Results are discussed from the perspectives of both research and practice with regard to prison-based HIV prevention efforts.  相似文献   
4.
We review the association between surgically resolvable aortic disease and horseshoe kidney with a discussion of diagnostic problems and therapeutic options.Male patient 81 years of age with horseshoe kidney and an abdominal aortic aneurysm that was discovered by chance in an abdominal ultrasound during a check-up for his prostate condition.A retroperitoneal approach was used in order to resect the aneurysm and perform an aorto-aortic bypass with no complications occurring. Two years after the diagnosis, the patient is still asymptomatic from a vascular point of view.The co-presence of horseshoe kidney and aortic disease needing surgical correction is infrequent, but it significantly increases the technical complexity of aortic reconstruction. A literature review is included.  相似文献   
5.
6.
7.
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1.  相似文献   
8.
9.
G12 monoclonal antibody (mAb), one of a library of constructed mAb directed against human sperm proteins, was found by immunoperoxidase staining to label the post-acrosomal and neck regions of fixed human cauda epididymal and ejaculated spermatozoa. Epithelium and fluid of caput epididymis were strongly labelled while there was no staining on testis and efferent ducts. Western lot analysis revealed that G12 antibody reacted with proteins of 17.5, 18 and 19 kDa in human spermatozoa. This pattern seems to be specific for mature human spermatozoa, as it has not been observed either in other human tissues tested, or in spermatozoa from different animals. SOB2, the corresponding protein, was isolated from NP40-extracted human spermatozoa by using preparative electrophoresis, followed by isoelectrofocusing according to its isoelectric point of 6.4 G12 Fab fragments strongly inhibited binding of human spermatozoa to zona-free hamster oocytes (up to 86% inhibition at 200 micrograms/ml). Impairment of binding was dependent on the concentration of purified G12 immunoglobulin (Ig)G1, and significant even at 10 micrograms/ml. There was no inhibitory effect of G12 antibody on sperm motility parameters or triggering of the acrosome reaction and it did not inhibit binding to human zona pellucida. These results indicate that SOB2 is likely to participate in membrane oocyte binding, and my be potential candidate for the development of a contraceptive vaccine.   相似文献   
10.
Extrinsic compression of the renal artery due to a fibromuscular band originating from the diaphragm was encountered in a 26-year-old patient who had systemic hypertension associated with stenosis and kinking of one of her renal arteries. After surgical decompression, the renal artery assumed a normal expansion with disappearance of hypertension. Six other cases of extrinsic compression of the renal artery have been found in the literature. Surgical treatment is mandatory in all cases because the mechanism that causes the lesion makes percutaneous transluminal angioplasty illusory.  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