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   326300篇
  免费   286702篇
  国内免费   40366篇
耳鼻咽喉   3255篇
儿科学   5885篇
妇产科学   2566篇
基础医学   92785篇
口腔科学   4007篇
临床医学   68303篇
内科学   99565篇
皮肤病学   5546篇
神经病学   23441篇
特种医学   11763篇
外科学   48215篇
综合类   77024篇
现状与发展   24篇
一般理论   2篇
预防医学   52335篇
眼科学   19227篇
药学   68015篇
  137篇
中国医学   53578篇
肿瘤学   17695篇
  2022年   5917篇
  2021年   6893篇
  2020年   9019篇
  2019年   14187篇
  2018年   14868篇
  2017年   16217篇
  2016年   14180篇
  2015年   15696篇
  2014年   16590篇
  2013年   17524篇
  2012年   19975篇
  2011年   22244篇
  2010年   24402篇
  2009年   31725篇
  2008年   19301篇
  2007年   15387篇
  2006年   13953篇
  2005年   12592篇
  2004年   13136篇
  2003年   11952篇
  2002年   11598篇
  2001年   13364篇
  2000年   8340篇
  1999年   12688篇
  1998年   13719篇
  1997年   13646篇
  1996年   14725篇
  1995年   14917篇
  1994年   14699篇
  1993年   13444篇
  1992年   12693篇
  1991年   12087篇
  1990年   11061篇
  1989年   10929篇
  1988年   10491篇
  1987年   9847篇
  1986年   9381篇
  1985年   8450篇
  1984年   6531篇
  1983年   6545篇
  1982年   7600篇
  1981年   7142篇
  1980年   6806篇
  1979年   6641篇
  1978年   5817篇
  1977年   6122篇
  1976年   5743篇
  1975年   5483篇
  1974年   5034篇
  1972年   4754篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Between 1969 and 1993, 123 patients were accepted in this unit for surgery for refractory hyperparathyroidism associated with chronic renal failure. Subtotal parathyroidectomy was the procedure of choice. At operation, four or more parathyroids were identified in 75% of patients. Methylene blue localised additional parathyroids in 32% of initial explorations in which it was used. Coincidental thyroid pathology was found in 8.3%, including papillary carcinoma in 2.4%. No further parathyroid surgery was required in 90% of patients at a mean of 6.6 years after operation. Reoperation (10%) was more likely to be required (14.3%) when less than four glands were found than when four or more were found (8.5%). Patients continuing on dialysis were more likely to need reoperation than those with functioning renal transplants.  相似文献   
992.
Y Yoshiike  S Suzuki  Y Watanuki    T Okubo 《Thorax》1995,50(2):139-142
BACKGROUND--The effects of beta 2 adrenergic agonists on chemoreceptors remain controversial. This study was designed to examine whether fenoterol, a beta 2 adrenergic agonist, increases the ventilatory responses to hypercapnia (HCVR) and hypoxia (HVR) in normal subjects. METHODS--HCVR was tested with a rebreathing method and HVR was examined with a progressive isocapnic hypoxic method in 11 normal subjects. Both HCVR and HVR were assessed by the slope of occlusion pressure (P0.1) or ventilation (VE) plotted against end tidal carbon dioxide pressure and arterial oxygen saturation, respectively. Respiratory muscle strength, spirometric values and lung volume were measured. After a single oral administration of 5 mg fenoterol or placebo HCVR and HVR were evaluated. RESULTS--Fenoterol treatment did not change the specific airway conductance or forced expiratory volume in one second. Respiratory muscle strength did not change. Fenoterol increased the slope of the HCVR of both P0.1 (from 0.251 (0.116) to 0.386 (0.206) kPa/kPa, average increase 71%) and VE (from 10.7 (3.4) to 15.1 (4.2) l/min/kPa, average increase 52%), and shifted the response curves to higher values. For the HVR fenoterol increased the slopes of both P0.1 and VE (from -4.06 (2.00) x 10(-3) to -7.99 (4.29) x 10(-3) kPa/%, an average increase of 83%, and from -0.221 (0.070) to -0.313 (0.112) l/min/%, a 44.5% increase, respectively), and shifted the response curves to higher values. CONCLUSION--Acute administration of fenoterol increases the ventilatory responses to both hypercapnia and hypoxia in normal subjects.  相似文献   
993.
The Forrest Report led to the introduction of the breast screening programme with the aim of reducing mortality from breast cancer. In 1989 a breast screening programme was introduced to the South Bucks District and now two cycles have been completed. The findings are of a high yield of good prognosis tumours 71% and 72%, respectively. These encouraging figures are reflected in a high response rate and with a fall in the incidence of non-screen-detected tumours.  相似文献   
994.
995.
Pulmonary arterial aneurysm presenting as an endobronchial mass.   总被引:1,自引:0,他引:1       下载免费PDF全文
P M Gibbs  A Hami 《Thorax》1995,50(9):1013-1017
The case is presented of a 25 year old man with haemoptysis who exsanguinated following endoscopic fine needle aspiration of an endobronchial mass. Necroscopic examination revealed an aneurysm of the proximal left pulmonary artery.  相似文献   
996.
Compliance with inhaled asthma medication in preschool children.   总被引:4,自引:1,他引:3       下载免费PDF全文
N A Gibson  A E Ferguson  T C Aitchison    J Y Paton 《Thorax》1995,50(12):1274-1279
BACKGROUND--Previous studies have shown poor compliance with regular drug therapy in children and adults with asthma. In preschool children the parents supervise and are responsible for drug administration, but little is known of compliance in this group. In addition, there are few data on the patterns of drug use of inhaled prophylactic asthma therapy or of the relation between compliance and symptom control. A study was undertaken to address these issues with the hypothesis that parental supervision would result in good compliance. METHODS--The subjects were 29 asthmatic children aged 15 months to five years already established on inhaled prophylactic medication delivered through a large volume spacer. The prescribed drug regimens varied between subjects. This was an observational study using an electronic inhaler timer device to record the date and time of each actuation of the aerosol canister. Diary cards were used for parallel recording of symptoms and parentally reported compliance with a drug regimen. RESULTS--Variable and generally poor compliance was demonstrated with a median of 50% of study days with full compliance (subject range 0-94%) and an overall median of 77% of prescribed doses of therapy taken during the study period. No relation was found between frequency of prescribed regimen and good compliance. Day care was associated with poorer compliance. No relation between good compliance and low symptom scores was found. CONCLUSION--Compliance with inhaled prophylactic therapy is poor in preschool children with asthma whose medication is administered under parental supervision.  相似文献   
997.
998.
999.
Neoplastic angioendotheliosis has rarely been described as a respiratory disease. A patient is described with pulmonary vascular involvement induced by neoplastic angioendotheliosis in pulmonary vessels.  相似文献   
1000.
Background - A case of primary thyroid T cell lymphoma leading to lethal tracheal perforation during chemotherapy is described.  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