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   195732篇
  免费   2781篇
  国内免费   1729篇
耳鼻咽喉   1277篇
儿科学   6784篇
妇产科学   3182篇
基础医学   18889篇
口腔科学   1847篇
临床医学   15230篇
内科学   33715篇
皮肤病学   898篇
神经病学   17362篇
特种医学   9619篇
外国民族医学   16篇
外科学   30806篇
综合类   6191篇
现状与发展   3篇
一般理论   1篇
预防医学   19248篇
眼科学   3431篇
药学   11798篇
  23篇
中国医学   1766篇
肿瘤学   18156篇
  2024年   80篇
  2023年   375篇
  2022年   1029篇
  2021年   1167篇
  2020年   880篇
  2019年   692篇
  2018年   22569篇
  2017年   18047篇
  2016年   20121篇
  2015年   1934篇
  2014年   2052篇
  2013年   1829篇
  2012年   8537篇
  2011年   22623篇
  2010年   19791篇
  2009年   12256篇
  2008年   20506篇
  2007年   22662篇
  2006年   1594篇
  2005年   3063篇
  2004年   4010篇
  2003年   4950篇
  2002年   3025篇
  2001年   746篇
  2000年   962篇
  1999年   702篇
  1998年   562篇
  1997年   511篇
  1996年   311篇
  1995年   320篇
  1994年   309篇
  1993年   173篇
  1992年   180篇
  1991年   229篇
  1990年   213篇
  1989年   173篇
  1988年   131篇
  1987年   125篇
  1986年   86篇
  1985年   70篇
  1984年   60篇
  1983年   48篇
  1982年   43篇
  1980年   46篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
122.
Mammalian bones have three distinct origins (paraxial mesoderm, lateral plate mesoderm, and neural crest) and undergo two different modes of formation (intra-membranous and endochondral). Bones derived from the paraxial mesoderm and lateral plate mesoderm mainly form through the endochondral process. During this process, hypertrophic chondrocytes play a vital role in inducing both osteogenesis and angiogenesis. One of the essential osteogenic factors secreted from hypertrophic chondrocytes is Indian hedgehog (Ihh). In contrast, bones derived from the neural crest mainly form through the intramembranous pro-cess and do not require Ihh. Thus, depending on their origin, bones have distinct signaling properties, which need to be considered in the research and application of bone biology.Presented at the 18th Annual Research Meeting of the Japanese Orthopaedic Association, Kitakyushu, Japan, October 17, 2003  相似文献   
123.
124.
Background Application of linear stapling devices for extrahepatic vascular control in liver surgery has been well-established. However, the technique for use of stapling devices in hepatic parenchymal transection is not well defined. Purpose To describe the safety and efficacy of our technique for use of vascular stapling devices in hepatic parenchymal transection during open right hepatic lobectomy is the purpose of this study. Methodology We reviewed our experience with 101 consecutive open right hepatic lobectomies performed by a single surgeon between January 2003 and July 2006, in which vascular staplers were utilized for the parenchymal transection phase. Results Of the 101 patients who underwent resection, 53 (52%) were female. The mean age was 58 years. Malignant disease was the indication for resection in the majority of patients (88%). Of those with cancer, 78% (69 of 89) had metastatic colorectal cancer, 6% (5 of 89) had metastatic neuroendocrine tumor, 4% (4 of 89) had hepatocellular carcinoma, 4% (4 of 89) had cholangiocarcinoma, and the remaining 8% were other metastatic cancers. Twelve patients (12%) underwent resection for hepatic adenoma or symptomatic benign disease (FNH or hemangioma). Forty-eight patients (48%) underwent a major ancillary procedure at the time of hepatic resection. Thirty-nine patients (39%) had a nonanatomic wedge resection of a left lobe lesion, 27 patients (27%) had one or more lesions treated with radiofrequency ablation (RFA), and 6 patients (6%) were treated with a synchronous bowel resection. The median total operative time was 336 min (range 155–620 min). A Pringle maneuver for temporary vascular inflow occlusion was utilized in all cases, with a median time of 9 min (range 4–17 min). Ten patients (10%) required blood transfusion during surgery or in the postoperative period. The maximum transfusion was 2 U of packed red blood cells (PRBC) in seven patients and 1 U of PRBC in three patients. The mean nadir postoperative hematocrit was 28.2. All patients with malignant disease had tumor-free margins at the completion of the procedure. The average hospital length of stay was 6.0 days. One patient (1%) developed a clinically significant bile leak requiring a postoperative endoscopic retrograde cholangiography (ERCP). No patient required reoperation. The 30 and 60-day postoperative survival was 100%. Conclusion These findings indicate that application of vascular stapling devices for parenchymal transection in major hepatic resection is a safe technique, with low transfusion requirements and minimal postoperative bile leak. The technique allows for rapid transection of the entire right hepatic lobe in under 10 min. Short video clips of the technique will be demonstrated. Presented at the 2007 American Hepato–Pancreato–Biliary Association, Las Vegas, Nevada, April 19–22, 2007 (oral presentation/video presentation).  相似文献   
125.
Conclusion  Quantification of nuclear cardiac images provides a secondary support in reading myocardial perfusion images and improves the reproducibility in the diagnosis of cardiovascular diseases. The technology for the remote Web reading of nuclear cardiac images and the quantitative data allows for an easy and secured access to patient studies without the limitations of time and space. The recent increasing interests and applications in molecular targeted imaging have opened a new field in nuclear cardiology, and absolute image quantification of the focal tracer uptake in the myocardium is exceedingly critical for the quantitative analysis of molecular targeted images.  相似文献   
126.
CASE REPORT: A 12-year-old boy who had a history of Kawasaki disease 9 years ago experienced a subarachnoid hemorrhage by ruptured right posterior cerebral artery aneurysm. On day 1 operation, as the aneurysm was very fragile and bled easily, two intraoperative ruptures, including a very premature rupture, were encountered. As a result, a left hemiparesis especially severe in the left hand was caused by the right anterior thalamic infarction due to the occlusion of a thalamo-perforating artery arising near the neck of the aneurysm. DISCUSSION: The histopathological examination of the intraoperative excised aneurysmal dome disclosed the thickening of the endothelial inner due to the endothelial hypertrophy and the invasion of inflammatory cells. This finding of the aneurysm was partially mimicking the finding of the coronary artery of the patients with Kawasaki disease. The combination of cerebral aneurysm and Kawasaki disease has never been reported until now, and the etiology of the aneurysm of this patient is unclear.  相似文献   
127.

Background  

The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis.  相似文献   
128.
129.
发挥远程教育优势推进医学继续教育发展   总被引:9,自引:0,他引:9  
《教育部关于加强高校网络教育学院管理提高教学质量的若干意见》中强调指出:高校网络教育学院要以在职人员的继续教育为主,要充分发挥网络教育的优势,为在职人员更新知识、增强技能、不断学习、不断提高提供良好的服务。然而,要使医学院校在开展继续教育中发挥更大的作用,推进医学继续教育的发展,远程教育不仅是解决这一问题的有效途径,而且将成为开展医学继续教育的强大动力。  相似文献   
130.
Abstract 10 embalmed cadaver forearms and wrists were dissected to determine the anatomical course of the superficial branch of the radial nerve in the distal forearm. The superficial radial nerve bifurcated in two branches at a mean of 54,7 mm proximal to the radial styloid. From the styloid process of the radius, the mean distance to the closest dorsal branch of the superficial radial nerve was 3,5 mm and the mean distance to the closest volar branch was 9,8 mm. The mean distance between the closest branch of the superficial radial nerve and Lister?s tubercle was 16,4 mm. The crossing point between the nerve and the cephalic vein was located at a mean of 54,3 mm proximal to the styloid process. At the level of styloid process the mean distance between the closest dorsal branch of the superficial radial nerve and the first dorsal compartment was 15,2 mm and between the closest volar branch and the first dorsal compartment 4,4 mm. Detailed knowledge of anatomic characteristics of the superficial branch of the radial nerve may help prevent injury during operations and treat traumatic lesions of the nerve. Because of great variations in the course of the superficial radial nerve we could not define an absolute safe zone for surgical procedures on the distal forearm. Iatrogenic lesions of the superficial radial nerve are described complications of percutaneous procedures. Therefore open surgical approaches are recommended. Daniela Klitscher and Lars Peter Müller contributed equally to this work.  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