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   191234篇
  免费   1862篇
  国内免费   94篇
耳鼻咽喉   1310篇
儿科学   7093篇
妇产科学   3436篇
基础医学   18786篇
口腔科学   1820篇
临床医学   13446篇
内科学   35058篇
皮肤病学   1194篇
神经病学   17614篇
特种医学   9333篇
外科学   30848篇
综合类   2605篇
一般理论   1篇
预防医学   19435篇
眼科学   2957篇
药学   10301篇
中国医学   759篇
肿瘤学   17194篇
  2023年   115篇
  2022年   208篇
  2021年   524篇
  2020年   230篇
  2019年   483篇
  2018年   22476篇
  2017年   17685篇
  2016年   19774篇
  2015年   1214篇
  2014年   1206篇
  2013年   1402篇
  2012年   8012篇
  2011年   22124篇
  2010年   19374篇
  2009年   11954篇
  2008年   20375篇
  2007年   22611篇
  2006年   1457篇
  2005年   3104篇
  2004年   4243篇
  2003年   5285篇
  2002年   3263篇
  2001年   878篇
  2000年   1077篇
  1999年   586篇
  1998年   312篇
  1997年   282篇
  1996年   188篇
  1995年   184篇
  1994年   171篇
  1993年   117篇
  1992年   160篇
  1991年   214篇
  1990年   227篇
  1989年   179篇
  1988年   122篇
  1987年   136篇
  1986年   113篇
  1985年   87篇
  1984年   69篇
  1983年   64篇
  1982年   52篇
  1980年   51篇
  1974年   45篇
  1970年   48篇
  1969年   46篇
  1968年   33篇
  1938年   60篇
  1932年   60篇
  1930年   47篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
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   
73.
74.
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   
75.
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   
76.
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   
77.
对17例人工绝育后曾行输卵管复通手术失败病例,进行再次显微输卵管复通手术,经随访二年以上,宫内妊娠率41.18%(7/17)。手术后成功率与输卵管吻合部位有关,峡部与壶腹部吻合效果最差。作者指出再次显微输卵管吻合手术对由于原吻合部位闭锁病例有一定的价值。但需慎重考虑如何提高初次吻合术质量、防止术后粘连是十分重要。  相似文献   
78.

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   
79.
80.
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