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   25481篇
  免费   1505篇
  国内免费   164篇
耳鼻咽喉   289篇
儿科学   843篇
妇产科学   692篇
基础医学   3558篇
口腔科学   660篇
临床医学   2256篇
内科学   4654篇
皮肤病学   489篇
神经病学   1974篇
特种医学   1215篇
外国民族医学   5篇
外科学   4089篇
综合类   671篇
一般理论   8篇
预防医学   1273篇
眼科学   730篇
药学   1614篇
  1篇
中国医学   100篇
肿瘤学   2029篇
  2023年   192篇
  2022年   226篇
  2021年   464篇
  2020年   327篇
  2019年   442篇
  2018年   627篇
  2017年   478篇
  2016年   573篇
  2015年   597篇
  2014年   772篇
  2013年   943篇
  2012年   1523篇
  2011年   1524篇
  2010年   899篇
  2009年   765篇
  2008年   1271篇
  2007年   1261篇
  2006年   1255篇
  2005年   1224篇
  2004年   1190篇
  2003年   1051篇
  2002年   1056篇
  2001年   895篇
  2000年   827篇
  1999年   721篇
  1998年   228篇
  1997年   210篇
  1996年   197篇
  1995年   154篇
  1994年   147篇
  1993年   108篇
  1992年   334篇
  1991年   303篇
  1990年   332篇
  1989年   321篇
  1988年   306篇
  1987年   303篇
  1986年   274篇
  1985年   247篇
  1984年   164篇
  1983年   156篇
  1982年   92篇
  1981年   105篇
  1979年   196篇
  1978年   117篇
  1977年   116篇
  1975年   93篇
  1974年   93篇
  1973年   109篇
  1972年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Subclavian artery lesion that is associated with low complication rate could be treated by percutaneous intervention effectively. However, the success of endovascular therapy for occlusive lesion may be limited by failure to cross with a guidewire. We describe the use of a system using optical coherence reflectometry for navigation and radiofrequency ablation to enable wire passage through subclavian artery occlusion that could not be crossed by conventional guidewires.  相似文献   
32.
The high technical complication rate of pancreas transplantation requires large animal models to improve clinical transplant survival rates. The pig is a very suitable animal due to its anatomy, physiology and immunology which are similar to humans. In this study a model of en-bloc simultaneous pancreas and kidney transplantation was established which--in contrast to separate transplantation of both organs--decreases preservation time, operation time, and clamp time. Furthermore, the rates of intra- and postoperative complications were reduced compared with separate transplantation. The donor aorta (encompassing celiac axis, superior mesenteric artery, and left renal artery) is anastomosed en-bloc to the recipients aorta in a an oblique-to-side fashion. The portal vein is anastomosed end-to-side to the left common iliac vein. The exocrine pancreatic secretions are drained via duodenocystostomy to allow for monitoring of urinary amylase for rejection. The en-bloc technique is an alternative for pediatric donor organs since the risk of vascular complications is lower compared with separate implantation of the donor vessels. Based on our results in a large animal model the en-bloc technique could be used in adult uremic diabetic patients who receive a combined pancreas-kidney transplant from a pediatric cadaver donor.  相似文献   
33.
Assisted reproduction (IVF/ICSI) is an established method for the treatment of infertility, though it entails a number of risks and limiting factors for the children and their families that really have to be considered and resolved. They also must be part of informative consultations before applying the selected (methods)/techniques. The following risks are of prime importance: 1. The increasing number of multiple pregnancies. Every multiple pregnancy has to be regarded as a complication of reproductive medicine: the rate of neonatal morbidity and mortality is higher compared to single pregnancies, and the emotional, logistic, and financial factors are significant for the concerned families. To limit these risks, it is preferable to perform only a single embryo transfer even though a lower rate of resulting pregnancies is to be expected. Of course it must be simultaneously provided that methods are developed and applied to transfer an embryo with high implantation potency. Based on existing/present results, the highest priority should not be given to pregnancy rates as high (as possible) but to the lowest possible complication rate for the infant with an acceptable pregnancy rate comparable to that achieved in fertile couples. 2. In assisted reproduction, the risk of fetal abnormalities seems to be elevated, but in some studies, according to the German IVF register, the selected method (ICSI) and other factors such as family abnormalities and environmental factors are relevant. Additional studies are required to clarify this subject and develop possible preventive strategies. 3. The children's psychomotoric development is normal as a rule. The risk of handicaps (retarded development spastic cerebral palsy) increases in accordance with the reduction of gestational period/age and the decrease of birth weight. This in turn is of particular significance in multiple pregnancies.  相似文献   
34.
Subtraction and conventional radiography were evaluated for their diagnostic potential to assess interradicular bone lesions in the mandibular premolar region. Both conventional radiographs and subtraction images were interpreted by 10 observers. The receiver-operating characteristic (ROC) technique was used to compare the two techniques. The diagnostic validity was higher for the subtraction technique, both for lesions confined to cancellous bone and for lesions including the cortical bone, than for the conventional technique. For bone defects confined to cancellous bone the diagnostic accuracy was lower than those reported from periapical bone lesions irrespective of whether subtraction or conventional radiography was used. We conclude that subtraction radiography improves the detectability of bone lesions, shallow ones in particular. Lesions in the interradicular bone are more difficult to detect than those in the periapical bone.  相似文献   
35.
36.
37.
38.
39.
40.
Reports available on the extent and incidence of cognitive deficits in human immunodeficiency virus (HIV-1) patients are variable. To assess the influence of drug abuse and psychiatric symptoms on the extent of the cognitive deficit, we examined 42 drug-addicted HIV-1 patients and compared them with a group of seronegative drug addicts (n = 31) as well as with a group of healthy controls (n = 50), using a psychometric test battery and standardized psychiatric scales. We found no significant difference in the extent and incidence of cognitive deficits in the group of HIV-1 patients as compared with the seronegative drug addicts. Both groups, however, differed from the normal population group. Remarkable depressive symptoms were found in the HIV-1 infected patient group. We assume that long-term drug abuse contributes markedly to the cognitive deficit of HIV-1 patients, which is further influenced by depressive symptoms.  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