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   261167篇
  免费   10641篇
  国内免费   772篇
耳鼻咽喉   3878篇
儿科学   7362篇
妇产科学   6157篇
基础医学   37002篇
口腔科学   9092篇
临床医学   15896篇
内科学   58510篇
皮肤病学   7432篇
神经病学   21587篇
特种医学   6439篇
外国民族医学   3篇
外科学   30152篇
综合类   1413篇
现状与发展   2篇
一般理论   55篇
预防医学   29426篇
眼科学   6448篇
药学   20069篇
中国医学   1274篇
肿瘤学   10383篇
  2023年   1436篇
  2022年   2114篇
  2021年   5357篇
  2020年   2845篇
  2019年   5288篇
  2018年   8083篇
  2017年   5041篇
  2016年   5064篇
  2015年   5749篇
  2014年   7105篇
  2013年   10439篇
  2012年   16659篇
  2011年   17731篇
  2010年   9126篇
  2009年   6995篇
  2008年   14130篇
  2007年   15081篇
  2006年   14235篇
  2005年   13842篇
  2004年   12702篇
  2003年   11837篇
  2002年   11120篇
  2001年   7542篇
  2000年   8348篇
  1999年   6594篇
  1998年   1337篇
  1997年   977篇
  1992年   3181篇
  1991年   2784篇
  1990年   2708篇
  1989年   2297篇
  1988年   2150篇
  1987年   2000篇
  1986年   2037篇
  1985年   1865篇
  1984年   1346篇
  1983年   1163篇
  1979年   1495篇
  1978年   997篇
  1977年   919篇
  1975年   1054篇
  1974年   1376篇
  1973年   1424篇
  1972年   1342篇
  1971年   1319篇
  1970年   1209篇
  1969年   1286篇
  1968年   1311篇
  1967年   1176篇
  1966年   1014篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
43.
44.
Gallibacterium anatis (previously named Pasteurella haemolytica-like) is considered a normal inhabitant of genital and upper respiratory tracts of healthy chickens, but it is also associated with different pathological conditions. Secreted metalloproteases from field and reference G. anatis cultures were obtained by methanol precipitation and were characterized. Proteins of molecular mass higher than 100 kDa showing proteolytic activity were observed in 10% polyacrylamide gels copolymerized with 1% bovine casein. They were active at alkaline pH, and inhibited by ethylenediamine tetraacetic acid. Their activity was stable at 50 degrees C, but partially inhibited at 60 degrees C, and totally inhibited at higher temperatures. Secreted proteins were able to degrade chicken IgG after 24 h of incubation, and cross-reacted with a polyclonal antibody against purified protease from Actinobacillus pleuropneumoniae. Secreted metalloproteases could play a role in infections caused by G. anatis.  相似文献   
45.
46.
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique.  相似文献   
47.
This study presents the case of a patient with necrobiosis or necrosing fascitis of the inguinal region, secondary to a complicated Amyand’s hernia with a concomitant ipsilateral Richter’s hernia. The patient was treated with open trans-abdominal surgery and hernia repair through the pre-peritoneal approach, plus anti-microbians, and thrice-daily wound cleansing and dressings to the inguinal region. Evolution was satisfactory. There are no reports in the literature of a case such as this.  相似文献   
48.
49.
INTRODUCTION: Ischemic heart disease is a major cause of heart failure in western societies. However, the factors that may influence left ventricular function (LVF) recovery after an acute coronary syndrome (ACS) are still unclear. OBJECTIVE: To identify variables that may influence LVF evolution one year after ACS. METHODS: 104 patients hospitalized with ACS between 7/1/2001 and 12/31/2002 and with systolic dysfunction--defined as an echocardiographic ejection fraction (EF) < or = 45%--were randomly allocated to a planned coronary follow-up program (FUP) or a general cardiology clinic (GC); patients from both groups were also randomly referred to a structured cardiac rehabilitation program (CRP). EF was re-assessed at one year. We compared differences between patients who recovered left ventricular function (EF > 45%; group 1) and those who did not (group 2). RESULTS: One year after discharge, 44.2% of the patients had recovered function. There were no significant differences between the groups in gender (77.7 vs. 76.5% male), age (56 vs. 59 years), hypertension, diabetes, dyslipidemia, smoking habits or family history. A previous history of cardiovascular events was more frequent in group 2 (11.1% vs. 35.3%, p = 0.03). Cardiac catheterization was performed before discharge in 88.8% and 88.2% in groups 1 and 2 respectively (p = NS); no differences were found in coronary anatomy between the two groups. Angioplasty was performed in 54.2% in group 1 and 50% in group 2 (p = NS). There were no differences in the use of angiotensin-converting enzyme inhibitors (83.3% vs. 87.5%), beta-blockers (87.5% vs. 87.5%), nitrates (37.5% vs. 33.3%), aspirin (95.8% vs. 95.8%), statins (79.1% vs. 75%) or diuretics (20.8% vs. 45.8%). There was no significant difference in LVF recovery between patients randomized to FUP or GC (38.5% vs. 54.5%). 87.5% of patients who completed the CRP had normal EF at one year compared to 32.7% of patients not referred to the program (p = 0.009). Although EF improved in both groups, this improvement was greater in patients who completed a CRP (EF 8% vs. 5%, p = 0.003). CONCLUSION: A previous cardiovascular event and completion of a CRP were the only variables that influenced LVF recovery. Thus, enrollment in a CRP, in addition to standard therapy, could be an important therapeutic measure in patients with systolic dysfunction after ACS; our data suggest that these programs should be more widely used.  相似文献   
50.
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