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   1341411篇
  免费   112775篇
  国内免费   6381篇
耳鼻咽喉   16744篇
儿科学   43061篇
妇产科学   36676篇
基础医学   183955篇
口腔科学   36320篇
临床医学   121036篇
内科学   279212篇
皮肤病学   31922篇
神经病学   110766篇
特种医学   55584篇
外国民族医学   275篇
外科学   210700篇
综合类   31550篇
现状与发展   2篇
一般理论   415篇
预防医学   106850篇
眼科学   28188篇
药学   93835篇
  5篇
中国医学   2229篇
肿瘤学   71242篇
  2018年   13422篇
  2017年   10681篇
  2016年   12849篇
  2015年   14358篇
  2014年   20022篇
  2013年   29830篇
  2012年   36381篇
  2011年   39039篇
  2010年   24453篇
  2009年   23971篇
  2008年   36518篇
  2007年   38926篇
  2006年   40033篇
  2005年   38626篇
  2004年   36865篇
  2003年   35976篇
  2002年   33957篇
  2001年   66135篇
  2000年   68010篇
  1999年   56684篇
  1998年   16763篇
  1997年   15048篇
  1996年   16035篇
  1995年   16250篇
  1994年   15121篇
  1993年   14175篇
  1992年   47154篇
  1991年   45811篇
  1990年   44024篇
  1989年   41868篇
  1988年   38803篇
  1987年   38116篇
  1986年   35893篇
  1985年   34666篇
  1984年   26389篇
  1983年   22131篇
  1982年   13878篇
  1981年   12468篇
  1980年   11730篇
  1979年   23564篇
  1978年   17085篇
  1977年   14407篇
  1976年   13197篇
  1975年   13736篇
  1974年   16115篇
  1973年   15425篇
  1972年   14200篇
  1971年   13049篇
  1970年   11895篇
  1969年   11130篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
OBJECTIVE: Colonic infarction is a recognized complication of abdominal aortic aneurysm (AAA) surgery. The clinical difficulty in establishing the diagnosis combined with the patient's poor physiological status is usually associated with a fatal outcome. We assessed our experience with this problem to identify a possible risk factor profile for these patients. METHOD: Patients records were identified from the operative logs, intensive care unit, Hospital Inpatient Enquiry system and vascular unit databases over a 6-year period. RESULTS: A total of 405 patients underwent AAA repair during this period; 140 as emergency ruptures. Nine patients were identified from the databases with known colonic infarction (2.2%). One was a woman. The mean age was 70 years. Seven patients had emergency ruptures (5%). Twenty independent risk factors were analysed using univariate and multivariate logistic regression models. Significant risk factors identified by using a multivariate analysis included the nature of the presenting patient, preoperative hypotension, prolonged cross-clamp time, intra-operative ischaemia and postoperative acidosis. Confirmatory diagnosis was made by colonoscopy in eight patients. One patient survived following the salvage surgery. The mean duration of survival was 10.5 days. The overall mortality was 89% of patients. CONCLUSION: In our unit infrarenal AAA repair has a 2.2% rate of colonic infarction. A definitive diagnosis is best made by colonoscopy. A risk factor profile for the development of colonic infarction may be constructed on the basis of specific clinical parameters. Earlier intervention on the basis of this profile may ultimately reduce the current excessive mortality.  相似文献   
992.
Presentations of acute appendicitis represent an ongoing challenge to surgeons. This case of retrocaecal perforated appendicitis presented clinically as a right lumbar abscess, with the concomitant new diagnosis of type 2 diabetes mellitus in a 66-year-old male. This case emphasises the importance of an abdominal CT scan in any patient presenting with unusual sepsis near the abdomen.  相似文献   
993.
994.
995.
996.
997.
998.
Chronic, recurrent, multifocal osteomyelitis (CRMO) is an obscure disease of bone, occurring in children. It appears to be an inflammatory condition with no obvious microbiological cause. Current treatments of antibiotics and anti-inflammatory medication appear to have limited success. This case report looks at two separate cases of CRMO where partial resection of the affected bone—the clavicle—leads to complete resolution of symptoms and regrowth of the excised bone.  相似文献   
999.
1000.
Pulmonary hypertension (PH) may complicate idiopathic pulmonary fibrosis (IPF) but the prevalence of PH in IPF remains undefined. The present authors sought to describe the prevalence of PH in IPF. The lung transplant registry for the USA (January 1995 to June 2004) was analysed and IPF patients who had undergone right heart catheterisation (RHC) were identified. PH was defined as a mean pulmonary arterial pressure ((Ppa)) > or =25 mmHg and severe PH as a (Ppa) >40 mmHg. Independent factors associated with PH were determined. Of the 3,457 persons listed, 2,525 (73.0%) had undergone RHC. PH affected 46.1% of subjects; approximately 9% had severe PH. Variables independently associated with mild-to-moderate PH were as follows: need for oxygen, pulmonary capillary wedge pressure (P(pcw)) and forced expiratory volume in one second (FEV(1)). Independent factors related to severe PH included the following: carbon dioxide tension, age, FEV(1), P(pcw), need for oxygen and ethnicity. A sensitivity analysis in subjects with P(pcw) <15 mmHg did not appreciably alter the present findings. Pulmonary hypertension is common in idiopathic pulmonary fibrosis patients awaiting lung transplant, but the elevations in mean pulmonary arterial pressure are moderate. Lung volumes alone do not explain the pulmonary hypertension. Given the prevalence of pulmonary hypertension and its relationship with surrogate markers for quality of life (e.g. activities of daily living), future trials of therapies for this may be warranted.  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