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   64480篇
  免费   3876篇
  国内免费   59篇
耳鼻咽喉   978篇
儿科学   1963篇
妇产科学   1500篇
基础医学   9680篇
口腔科学   2323篇
临床医学   5974篇
内科学   11862篇
皮肤病学   1572篇
神经病学   6830篇
特种医学   2906篇
外国民族医学   1篇
外科学   8759篇
综合类   225篇
一般理论   34篇
预防医学   4637篇
眼科学   1283篇
药学   4306篇
中国医学   96篇
肿瘤学   3486篇
  2023年   397篇
  2022年   310篇
  2021年   633篇
  2020年   683篇
  2019年   759篇
  2018年   1458篇
  2017年   1254篇
  2016年   1581篇
  2015年   1329篇
  2014年   1516篇
  2013年   2705篇
  2012年   3539篇
  2011年   3992篇
  2010年   2083篇
  2009年   1377篇
  2008年   3841篇
  2007年   4047篇
  2006年   3757篇
  2005年   3677篇
  2004年   3559篇
  2003年   3589篇
  2002年   3511篇
  2001年   2646篇
  2000年   3364篇
  1999年   1824篇
  1998年   611篇
  1997年   536篇
  1996年   394篇
  1995年   325篇
  1994年   345篇
  1993年   332篇
  1992年   343篇
  1991年   289篇
  1990年   275篇
  1989年   338篇
  1988年   256篇
  1987年   263篇
  1986年   255篇
  1985年   323篇
  1984年   343篇
  1983年   289篇
  1982年   273篇
  1981年   226篇
  1980年   214篇
  1979年   266篇
  1978年   209篇
  1977年   210篇
  1976年   206篇
  1975年   186篇
  1973年   202篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
23.
24.
25.
26.
Type 1 diabetes is one of the commonest chronic disorders encountered in children and adolescents. When it first becomes apparent in children, approximately 20% of them have clinical and biochemical signs of ketoacidosis (DKA). In the presence of unusual clinical symptoms it is necessary to consider the possibility of associated conditions, such as coeliac disease, immunothyroiditis and Addison’s disease. Children with diabetes must be treated by a multidisciplinary team made up of paediatrician, paediatric diabetes specialist, psychologist, social worker, ophthalmologist, dietitian, nurse and diabetes counsellor, making it essential for them to be treated in regional specialised centres. They are treated in their own psychosocial environment and their families are involved in the therapy. Comprehensive, multidisciplinary treatment strategies have now made it possible for these patients to enjoy normal physical wellbeing and near-normal psychosocial development. Prevention and early treatment of of disturbances associated with diabetes remain an important concern. The fact that type 2 diabetes must now be looked for in overweight children and adolescents is a new aspect of diabetes medicine.  相似文献   
27.
BACKGROUND: The laparoscopic resection of rectal cancer shows morbidity and oncological safety comparable to the open approach, but morbidity increases after conversion to open resection. No oncological long-term results are available for the latter patients. METHODS: From 01/01/2000-31/12/2002, patients with curatively resected rectal cancer enrolled in a observational study were evaluated for morbidity, mortality, tumor- and local recurrence rate, paying attention to patients with conversion from laparoscopic to open resection. RESULTS: 237 (3.3%) of 7,189 patients underwent laparoscopic resection (ITT). These patients showed significantly more T1/2 tumors (P<0.001) in earlier UICC stages (P<0.001) than open resected patients. 35 (14.8%) of 237 laparoscopic procedures were converted. Compared with patients receiving complete laparoscopic or open resection, these patients showed significantly higher frequencies of intraoperative (P<0.001) and general postoperative complications (P=0.003) as well as the highest overall morbidity (P=0.031). After a median follow-up of 30.1 months, the highest 5-year local recurrence rate was found in the converted group (16.0%). The laparoscopically resected patients showed a local recurrence rate of 3.3%, patients with open resection of 12.4% (P=0.082). The disease-free survival rate did not differ between the groups (P=0.585). CONCLUSION: Laparoscopic resection of rectal cancer provides oncological results similar to open resection. After conversion, the short and oncological long-term outcomes were worse. Considering a conversion rate of 15%, only a strict indication for the laparoscopic approach can be allowed, and laparoscopic resection should be performed at centers.  相似文献   
28.
29.
BACKGROUND: Common clinical forms of oral lichen planus (OLP) and oral lichenoid reactions (OLR) are erythematous (ERY) or reticular (RET). The purpose of this study was to find histopathological changes that differ between these forms. METHODS: Epithelial thickness, epithelial proliferation rate, apoptosis, and HLA-DR expression were compared among 10 reticular and 12 erythematous lesions, and 11 normal oral mucosa samples (NOM). RESULTS: The epithelium in ERY was thinner than in NOM, whereas RET showed values between ERY and NOM. Cell proliferation increased significantly in ERY as compared with RET and NOM, with no difference between RET and NOM. Relative numbers of epithelial cell nuclei displaying visible chromatin condensation were reduced in ERY form. CONCLUSIONS: The markedly increased cell proliferation in ERY supports the notion that this form displays a higher disease activity as compared to RET. It can therefore be important to study each disease form separately.  相似文献   
30.
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