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   1373444篇
  免费   98503篇
  国内免费   5863篇
耳鼻咽喉   20136篇
儿科学   40565篇
妇产科学   38955篇
基础医学   190808篇
口腔科学   40427篇
临床医学   117389篇
内科学   267184篇
皮肤病学   30657篇
神经病学   108000篇
特种医学   55303篇
外国民族医学   446篇
外科学   212877篇
综合类   39053篇
现状与发展   20篇
一般理论   438篇
预防医学   95004篇
眼科学   32204篇
药学   104284篇
  38篇
中国医学   5668篇
肿瘤学   78354篇
  2018年   13173篇
  2016年   11835篇
  2015年   13793篇
  2014年   18976篇
  2013年   27625篇
  2012年   36173篇
  2011年   38295篇
  2010年   23218篇
  2009年   22248篇
  2008年   35786篇
  2007年   38845篇
  2006年   39152篇
  2005年   37759篇
  2004年   36216篇
  2003年   34998篇
  2002年   34388篇
  2001年   64215篇
  2000年   65865篇
  1999年   55874篇
  1998年   14896篇
  1997年   13714篇
  1996年   13147篇
  1995年   12407篇
  1994年   11622篇
  1992年   42842篇
  1991年   41354篇
  1990年   40626篇
  1989年   39605篇
  1988年   37014篇
  1987年   36438篇
  1986年   34925篇
  1985年   33108篇
  1984年   24837篇
  1983年   21053篇
  1982年   12675篇
  1981年   11575篇
  1979年   23928篇
  1978年   17076篇
  1977年   14838篇
  1976年   13389篇
  1975年   15271篇
  1974年   18084篇
  1973年   17564篇
  1972年   16817篇
  1971年   15720篇
  1970年   14915篇
  1969年   14346篇
  1968年   13460篇
  1967年   12015篇
  1966年   11258篇
排序方式: 共有10000条查询结果,搜索用时 2 毫秒
91.
Abstract Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region. A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the elderly, as early diagnosis leads to effective treatment and prevention of complications.  相似文献   
92.
93.
A new semi-empirical formula for the evaluation of (n,(3)He) reaction cross-sections at the energy of 14.6 and 20 MeV is presented. Formula was derived using the analytical expression for the evaluation of the (3)He spectrum within the frame of pre-equilibrium exciton model. The systematics obtained is compared with the empirical formula for the (n,(3)He) reaction cross-section.  相似文献   
94.
95.
96.
Intraoperative and postoperative free flap monitoring by means of oxygen tension measurement was carried out in 11 patients. We used an invasive flexible microcatheter that allowed for measurement of oxygen tension in all types of free flaps. Two cases of the measured flaps were buried free flaps which do not allow monitoring by clinical assessment. All flaps monitored in this study survived. One case of displacement of the microcatheter occurred. In one patient, the tissue pO2 monitor successfully detected early vascular thrombosis with subsequent reoperation and salvage of the free flap.  相似文献   
97.
This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome.  相似文献   
98.
BG Aktuell     
This paper gives an overview of the changes in the sector of accident insurance companies over recent months and a prognosis for the changes that can still be expected, especially with reference to the election results.  相似文献   
99.
Consecutive patients (n = 215) who were referred to optometric (55%) or multidisciplinary (45%) low-vision services and above 50 years of age were recruited from four hospitals in the Netherlands. They completed two vision-related quality of life questionnaires, the Vision Quality of Life Core Measure (VCM1) and the Low Vision Quality of Life Questionnaire (LVQOL), before their first visit with low-vision services and 1 year later. At follow-up, patients referred to multidisciplinary low-vision services had lower scores on the mobility subscale of the LVQOL than patients referred to optometric low-vision services [5.3 points; 95% confidence interval (CI): 0.2-10.5]. Paired sample t-tests for the two groups of patients taken together show improvement for the VCM1 (3.1 points; 95% CI: 0.6-5.6) and deterioration for the basic aspects of vision (3.5 points; 95% CI: 1.1-5.9) and the mobility (6.6 points; 95% CI: 3.7-9.5) subscales of the LVQOL. In conclusion, people referred to optometric services showed less deterioration in mobility than those referred to multidisciplinary services. No differences were observed for any of the other subscales of the LVQOL and the VCM1. Future research in this field should include randomized controlled designs comparing low-vision services with no treatment or placebo.  相似文献   
100.
内镜辅助方型脸改型术   总被引:4,自引:0,他引:4  
目的探讨内镜在方型脸改型术中的临床应用效果。方法采用口内入路,在内镜辅助下,用高速涡轮气钻截除肥大下颌角、切除部分咬肌和颊脂垫,进行方型脸的面部改型。结果本组共38例,其中男3例,女35例,年龄21~40岁。内镜完全可以清楚显示下颌升支、下颌角、下颌体下缘,视野清晰。使用高速涡轮气钻截除肥大下颌角可以更加精确和容易,且创伤小,出血少,手术时间短,感染风险低。下面部轮廓改善满意。结论内镜辅助方型脸改型术,有助于获得良好的手术效果。  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