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   205052篇
  免费   3469篇
  国内免费   63篇
耳鼻咽喉   1384篇
儿科学   7613篇
妇产科学   3798篇
基础医学   20298篇
口腔科学   1992篇
临床医学   16520篇
内科学   36237篇
皮肤病学   1083篇
神经病学   19079篇
特种医学   9580篇
外国民族医学   1篇
外科学   32916篇
综合类   2831篇
一般理论   61篇
预防医学   21612篇
眼科学   3177篇
药学   11357篇
  1篇
中国医学   659篇
肿瘤学   18385篇
  2023年   351篇
  2022年   494篇
  2021年   1055篇
  2020年   675篇
  2019年   1066篇
  2018年   22888篇
  2017年   18073篇
  2016年   20169篇
  2015年   1837篇
  2014年   2056篇
  2013年   2488篇
  2012年   9372篇
  2011年   23306篇
  2010年   20032篇
  2009年   12563篇
  2008年   21278篇
  2007年   23534篇
  2006年   2254篇
  2005年   3816篇
  2004年   4854篇
  2003年   5638篇
  2002年   3679篇
  2001年   593篇
  2000年   675篇
  1999年   446篇
  1998年   469篇
  1997年   430篇
  1996年   267篇
  1995年   237篇
  1994年   220篇
  1993年   168篇
  1992年   241篇
  1991年   282篇
  1990年   294篇
  1989年   212篇
  1988年   190篇
  1987年   154篇
  1986年   166篇
  1985年   160篇
  1984年   124篇
  1983年   110篇
  1982年   90篇
  1980年   89篇
  1979年   89篇
  1978年   87篇
  1974年   77篇
  1973年   72篇
  1972年   71篇
  1968年   63篇
  1932年   63篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
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   
65.
66.
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   
67.
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   
68.
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   
69.

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   
70.
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