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   1286篇
  免费   90篇
  国内免费   12篇
耳鼻咽喉   3篇
儿科学   33篇
妇产科学   6篇
基础医学   113篇
口腔科学   15篇
临床医学   95篇
内科学   314篇
皮肤病学   14篇
神经病学   41篇
特种医学   143篇
外科学   269篇
综合类   16篇
预防医学   22篇
眼科学   10篇
药学   107篇
肿瘤学   187篇
  2022年   10篇
  2021年   21篇
  2020年   6篇
  2019年   10篇
  2018年   18篇
  2017年   8篇
  2016年   11篇
  2015年   25篇
  2014年   25篇
  2013年   48篇
  2012年   38篇
  2011年   48篇
  2010年   58篇
  2009年   60篇
  2008年   47篇
  2007年   86篇
  2006年   68篇
  2005年   52篇
  2004年   47篇
  2003年   68篇
  2002年   53篇
  2001年   42篇
  2000年   35篇
  1999年   51篇
  1998年   44篇
  1997年   45篇
  1996年   42篇
  1995年   35篇
  1994年   31篇
  1993年   24篇
  1992年   12篇
  1991年   10篇
  1990年   10篇
  1989年   26篇
  1988年   14篇
  1987年   14篇
  1986年   14篇
  1985年   12篇
  1984年   7篇
  1983年   7篇
  1982年   8篇
  1981年   11篇
  1980年   6篇
  1979年   6篇
  1978年   11篇
  1977年   14篇
  1976年   10篇
  1975年   11篇
  1972年   5篇
  1968年   4篇
排序方式: 共有1388条查询结果,搜索用时 0 毫秒
11.
A new fibrin adhesive "Beriplast" of the Behringwerke AG Marburg was implemented for conjunctival glueing in 42 patients after intracapsular cataract extraction. The tissue adhesive was also examined in palpebral tumour surgery as to its compatibility and usefulness. Good functional and cosmetic results were obtained with regard to the conjunctiva and the eyelids, respectively. No cases of incompatibility were registered.  相似文献   
12.
13.
14.
15.
目的 研究正常胰腺、慢性胰腺炎与胰腺癌组织中软骨寡聚基质蛋白(cartilage oligomeric matrix protein,COMP)mRNA和蛋白表达水平的差异,揭示COMP在慢性胰腺炎样损伤中的意义。方法 采用Northern印迹法、Western印迹法、原位杂交法与免疫组化方法对14例慢性胰腺炎、14例胰腺癌及15例正常胰腺组织进行分析。结果 在慢性胰腺炎组织中和胰腺癌组织中类似慢性胰腺炎损伤的退变腺泡细胞胞浆内,存在高水平的COMP mRNA信号与免疫反应;而在胰腺癌细胞、正常胰腺组织的导管细胞与胰岛细胞的胞浆内,COMP mRNA信号与免疫反应微弱或缺如。结论 COMP在慢性胰腺炎及胰腺癌中类似慢性胰腺炎损伤的退变腺泡细胞内高表达,可能与慢性胰腺炎中腺泡细胞功能异常有关。  相似文献   
16.
目的 了解P物质受体-神经激肽1受体(NK-1R)在正常肠管和溃疡性结肠炎组织中的表达,探讨该受体在溃疡性结肠炎的病理生理过程中所起的作用。方法 21个溃疡性结肠炎标本取自因该病并发症而手术的患。正常肠管组织取自24个器官捐献,应用逆转录聚合酶链反应(RT-PCR)技术检测正常肠管和溃疡性结肠炎组织NK-1R的信使核糖核酸(mRNA)水平,应用Western blot技术检测NK-1R的蛋白水平,应用免疫组织化学方法(免疫组化)进行NK-1R的组织学定位。结果 与正常肠管相比,溃疡性结肠炎组织中NK-1RmRNA和蛋白都过度表达,免疫组化检查显示,NK-1R的表达主要位于溃疡性结肠炎组织的肠黏膜表面,黏膜固有层的单核细胞,黏膜下层的动,静脉和纵形与环形肌层等处。结论 溃疡性结肠炎组织中NK-1R的表达水平明显上调,扰乱了神经激肽的作用环节,加剧肠管的病理改变。  相似文献   
17.
18.
Background The value of re-exploration for pancreatic ductal adenocarcinoma after the initial diagnosis of unresectability is unclear. Methods In this study, we analyzed 33 patients who were re-explored after an initial diagnosis of unresectability. Results At the time of reoperation, a resectable tumor was found in 18 patients: therefore, 15 pancreaticoduodenectomies, two total pancreatectomies and one left resection were performed with three vascular resections. Morbidity and mortality rates for the cohort were 6/33 and 1/33, without significant differences between resectable and nonresectable patients. Length of stay, duration of operation, and blood loss were significantly increased in the resection group. Kaplan–Meier survival analysis demonstrated increased median survival for resected patients (1078 days after the initial operation versus 547 days in the group of unresectable patients; p = 0.018). Analysis of the reasons against initial resection showed that, if the patients had been sent to a tertiary referral center for pancreatic surgery, a different decision in favor of resection would probably have been made in 14 out of 33 patients. A review of 10 published reports on reoperation for pancreatic cancer revealed results comparable to our study in terms of low morbidity and mortality as well as a survival benefit. Conclusions Reoperation for pancreatic ductal adenocarcinoma that is initially deemed unresectable can be safely performed in a selected group of patients by experienced surgeons, supporting the concept of patient centralization in pancreatic surgery. Resection at the second operation may confer a survival benefit even when the initial findings preclude a potentially curative approach.  相似文献   
19.
BACKGROUND: Patients with occult metastasis or locally nonresectable pancreatic cancer found during surgical exploration have a limited life expectancy. We sought to define markers in these patients that could predict survival and thus aid decision making for selection of the most appropriate therapeutic palliative option. METHODS: In a prospective 4-year single-center study, 136 consecutive patients with obstructive pancreatic cancer and intraoperative diagnosis of nonresectable or disseminated pancreatic cancer underwent a palliative surgical bypass procedure. Potential factors predicting survival were evaluated. RESULTS: Ninety-eight patients had metastatic disease and 38 locally advanced disease. Surgical morbidity rate was 16 %, re-operation rate 1%, and overall in-hospital mortality 4%. Univariate analysis showed American Society of Anesthesiologists (ASA) score, pain, operation time, presence of metastasis, and levels of leukocytes, albumin, C-reactive protein (CRP), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19-9 were associated significantly with survival. The multivariate analysis identified ASA score, presence of liver metastasis, pain, CA 19-9, and CEA levels as independent indicators for poor survival. Patients with none or 1 of these risk factors had a median survival of 13.5 months, whereas patients with 4 or 5 risk factors had a median survival of 3.5 months. CONCLUSIONS: The clinical markers identified predict poor outcome for patients with palliative bypass surgery and therefore aid the appropriate selection of either surgical bypass or endoscopic stenting in these patients.  相似文献   
20.
Chronic wounds are characterized by failure in wound-healing response and a delay in healing or nonclosure of the wounds. This results in a high effort in clinical treatment and/or home care. A major difference between acute wounds and chronic wounds is the imbalance of proteinase inhibitors and proteinase activity that regulates the degradation and regeneration of the extracellular matrix proteins. Collagen and collagen/oxidized regenerated cellulose dressings act as a competitive substrate for matrix metalloproteinase-2, matrix metalloproteinase-9, and bacterial collagenase and influence this imbalance positively. Both wound dressings, approved for chronic wound treatment, the bovine collagen type I sponge and the oxidized regenerated cellulose collagen sponge, did not differ significantly in their sorption profiles for all enzymes. In general, binding was enhanced with a longer incubation time. The density of the device and the accessible surface, which can be controlled by the manufacturing process, are the crucial factors for the efficiency of the wound dressing.  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