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   11016篇
  免费   398篇
  国内免费   37篇
耳鼻咽喉   71篇
儿科学   226篇
妇产科学   92篇
基础医学   1380篇
口腔科学   229篇
临床医学   691篇
内科学   2686篇
皮肤病学   113篇
神经病学   859篇
特种医学   447篇
外科学   2083篇
综合类   38篇
预防医学   464篇
眼科学   154篇
药学   858篇
  1篇
中国医学   14篇
肿瘤学   1045篇
  2024年   26篇
  2023年   71篇
  2022年   116篇
  2021年   221篇
  2020年   137篇
  2019年   177篇
  2018年   179篇
  2017年   163篇
  2016年   176篇
  2015年   183篇
  2014年   266篇
  2013年   370篇
  2012年   568篇
  2011年   636篇
  2010年   323篇
  2009年   247篇
  2008年   515篇
  2007年   597篇
  2006年   576篇
  2005年   613篇
  2004年   585篇
  2003年   572篇
  2002年   543篇
  2001年   256篇
  2000年   236篇
  1999年   255篇
  1998年   154篇
  1997年   148篇
  1996年   141篇
  1995年   123篇
  1994年   116篇
  1993年   112篇
  1992年   218篇
  1991年   207篇
  1990年   191篇
  1989年   168篇
  1988年   146篇
  1987年   131篇
  1986年   135篇
  1985年   128篇
  1984年   86篇
  1983年   87篇
  1982年   61篇
  1981年   43篇
  1980年   48篇
  1979年   52篇
  1978年   31篇
  1975年   29篇
  1974年   42篇
  1972年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Absorption spectra were measured for poly(N-vinylcarbazole) (PNVC), fractionated by means of the gel-permeation chromatographic technique. The intensities of the UV absorption bands of the carbazolyl group diminished with increasing molecular weight of the polymer from 1200 to ca. 104, and were constant when the molecular weight was higher than 104. The diminution of the absorption intensities was regarded as a hypochromism, and the hypochromism was discussed with respect to the local structure of PNVC in solution.  相似文献   
92.
Supporting glial cells of the peripheral nervous system include satellite cells of dorsal root ganglia and Schwann cells of peripheral nerves. In the central nervous system, glial cells contain enzymes related to the tricarboxylic acid and glutamine cycles: pyruvate carboxylase, glutamate dehydrogenase, and glutamine synthetase. The present study used immunohistochemistry in the rat peripheral nervous system to determine the cellular distribution of these enzymes along with glutamine. In dorsal root ganglia and peripheral nerves, glutamine and glutamine related enzymes were enriched in satellite and Schwann cells. In the dorsal root ganglia, immunoreactive satellite cells surrounded neurons of all sizes. In peripheral nerve, immunoreactive Schwann cells were most easily observed surrounding large diameter, myelinated axons. These Schwann cells contained immunoreactivity in their cell bodies, nodes of Ranvier, and the rim of cytoplasm outside the myelin sheath. Myelin sheaths were non-immunoreactive. The peripheral glial tricarboxylic and glutamine cycles may be used to produce glutamine for neuronal cell uptake and conversion to glutamate for synaptic transmission. Alternatively, these cycles may function in peripheral glia similar to central nervous system astrocytes for supporting the energy demands of neurons.  相似文献   
93.
94.
Objectives Several studies have reported that the secretory immunoglobulin A (S-IgA) concentration in saliva is an indicator of psychological stress. The aim of this study was to clarify the relationship between S-IgA and the stress from academic examinations. Methods S-IgA levels in 10 medical student volunteers from the second year course between May 4 and July 13, 2000 were examined using the ELISA method. Results There was a tendency for S-IgA in saliva to be higher on the day before academic examinations and during them, and lower on the days between these examinations. Conclusions It may be possible to use this measurement to monitor psychological stress in students and workers. Second year medical student in the year 2000.  相似文献   
95.
96.
97.
Ajisaka H  Maeda K  Uchiyama A  Miwa A 《Surgery today》2002,32(10):887-890
Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma, but it rarely develops as a primary tumor in the breast. Furthermore, no case of the myxoid variant of MFH in the breast has ever been documented. We report the case of a 52-year-old woman with a breast tumor that was immunohistochemically confirmed to be myxoid MFH. She underwent a radical mastectomy and is currently well with no evidence of local recurrence or metastatic spread after 3 years of follow-up. Received: August 6, 2001 / Accepted: March 5, 2002  相似文献   
98.
The purpose of this study was to review our experience with laparoscopic common bile duct (CBD) exploration by the transcystic approach and choledochotomy. We selected the transcystic approach for patients whose CBD stones were less than five in number and smaller than 9 mm in diameter, and whose CBD was less than 15 mm in diameter on cholangiograms. Among 217 patients with CBD stones treated laparoscopically, the transcystic approach was performed successfully in 91 of 104 patients in whom it was attempted (87.5%). The other 126 patients underwent laparoscopic choledochotomy, followed by ductal closure with transcystic drainage in 59, T-tube drainage in 46, primary ductal closure in 19, and choledochoduodenostomy in 1. Choledochotomy was converted to open surgery in only 1 patient. The transcystic approach was associated with shorter hospital stay and less morbidity than choledochotomy. However, choledochotomy also had an acceptably low rate of complications. Bile leaks occurred more frequently in those with primary ductal closure than in those with transcystic drainage or T-tube drainage. Residual stones were found in 2 patients with the transcystic approach and in 10 with choledochotomy. The residual stones were removed through the T-tube tract by choledochoscopy in 7 of these 10 patients. From these results we conclude that laparoscopic management of CBD stones is feasible for almost all patients with CBD stones. It is considered to be safe and effective and has the advantage of being a single-stage procedure. Received: July 7, 2000 / Accepted: October 26, 2000  相似文献   
99.
Major gastrointestinal bleeding is a rare manifestation of intestinal Behçet's disease. We report herein the case of a 64-year-old man with intestinal Behçet's disease complicated by myelodysplastic syndrome who suffered massive hemorrhage. Colonoscopy demonstrated ulceration of the entire colon from the cecum to the rectum, characterized by punched-out ulcers. Angiography demonstrated apparent extravasation of contrast material in the terminal ileum, and embolization was not successful. Continued and massive bleeding necessitated surgical resection of the involved segment of ileum; however, massive bleeding recurred. Re-endoscopy showed oozing hemorrhage from the multiple colon ulcerations. Intra-arterial prednisolone injection therapy was given, following which the melena gradually subsided and completely stopped within a few days.  相似文献   
100.
Because of the low incidence rate of combined hepatocellular–cholangiocarcinoma (combined HCC-CC), the clinicopathological features of a recurrent tumor of this disease remain to be elucidated. We describe a 47-year-old Japanese woman with a 5-cm diameter mass lesion in the liver. A hepatectomy and dissection of the local lymph nodes were performed and a histological examination of the resected specimen showed combined HCC-CC. After a follow-up of 15 months, intrahepatic recurrence was observed, and a hepatectomy was performed again followed by hepatic arterial infusion chemotherapy. A histological examination revealed that the recurrent tumors consisted of only cholangioacarcinoma. A disease-free survival was obtained for about 7 years after the recurrence. To improve the poor prognosis of combined HCC-CC, clinicopathological features of this disease and the therapy selection for recurrent tumors should be discussed. Received: March 12, 2001 / Accepted: November 20, 2001  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