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   3481867篇
  免费   286093篇
  国内免费   13386篇
耳鼻咽喉   47507篇
儿科学   110460篇
妇产科学   90318篇
基础医学   553520篇
口腔科学   94043篇
临床医学   319336篇
内科学   613845篇
皮肤病学   91828篇
神经病学   297128篇
特种医学   135484篇
外国民族医学   295篇
外科学   530033篇
综合类   103363篇
现状与发展   24篇
一般理论   2408篇
预防医学   300092篇
眼科学   79103篇
药学   238807篇
  27篇
中国医学   9382篇
肿瘤学   164343篇
  2021年   55118篇
  2020年   35123篇
  2019年   58096篇
  2018年   71523篇
  2017年   54536篇
  2016年   59944篇
  2015年   74093篇
  2014年   108222篇
  2013年   173443篇
  2012年   95857篇
  2011年   96729篇
  2010年   117433篇
  2009年   121656篇
  2008年   83594篇
  2007年   87444篇
  2006年   97150篇
  2005年   92942篇
  2004年   94471篇
  2003年   84996篇
  2002年   74826篇
  2001年   104221篇
  2000年   96991篇
  1999年   96760篇
  1998年   64917篇
  1997年   62859篇
  1996年   61031篇
  1995年   56431篇
  1994年   50702篇
  1993年   47347篇
  1992年   68839篇
  1991年   66069篇
  1990年   62633篇
  1989年   61746篇
  1988年   57562篇
  1987年   56319篇
  1986年   53674篇
  1985年   53254篇
  1984年   48969篇
  1983年   45041篇
  1982年   42066篇
  1981年   39712篇
  1980年   37396篇
  1979年   41393篇
  1978年   36730篇
  1977年   33272篇
  1976年   30536篇
  1975年   29406篇
  1974年   31009篇
  1973年   30074篇
  1972年   28295篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
152.
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   
153.
154.
155.
156.
157.
158.
159.
160.
Liver disease alters the pharmacokinetic and pharmacodynamic properties of hepatically eliminated drugs. The main factors influenced are plasma albumin levels, enzyme balance (induction & inhibition) and drug binding to tissue proteins. The influence of lidocaine on serum, heart and liver propranolol levels in Wistar rats after liver injury induced by carbon tetrachloride CCl4 0.4 ml/kg x 2/wkl, was investigated. 40 male Wistar rats were divided into four groups (I, II, III, IV; n=10), Group I animals received only propranolol (labelled + cold substance) 40 mg/kg/12 h p.o., group II propranolol plus lidocaine in a single dose of 4mg/kg s.c., group III was treated with CCl4 for 6 weeks and received propranolol x2 at the same dosage as group I, while group VI was treated with CCl4 and the same drug dosage as group II. The simultaneous administration of H3-propranolol and lidocaine increased propranolol levels in the serum and tissues. The liver in damaged animals showed an increase of propranolol level under lidocaine co-administration, probably due to CCl4 induced liver enzyme activity, resulting in a rapid propranolol metabolism or to competition between both drug protein binding sites. The increased propranolol levels in the heart after lidocaine administration were probably due to attributed to its high affinity for heart tissue. Consequently, as regards the therapeutic approach for patients with liver disease receiving propranolol their propranolol dosage should be reduced when lidocaine is co-administered.  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