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   1076649篇
  免费   71683篇
  国内免费   1384篇
耳鼻咽喉   15026篇
儿科学   34659篇
妇产科学   28655篇
基础医学   153633篇
口腔科学   29561篇
临床医学   94992篇
内科学   203993篇
皮肤病学   24420篇
神经病学   81552篇
特种医学   42996篇
外国民族医学   201篇
外科学   163454篇
综合类   21722篇
现状与发展   1篇
一般理论   263篇
预防医学   74630篇
眼科学   24552篇
药学   86236篇
  7篇
中国医学   2813篇
肿瘤学   66350篇
  2019年   7791篇
  2018年   11338篇
  2017年   8948篇
  2016年   10136篇
  2015年   11309篇
  2014年   15326篇
  2013年   22267篇
  2012年   30650篇
  2011年   32399篇
  2010年   19025篇
  2009年   17858篇
  2008年   30026篇
  2007年   32154篇
  2006年   32795篇
  2005年   31125篇
  2004年   29805篇
  2003年   28614篇
  2002年   27620篇
  2001年   60071篇
  2000年   61516篇
  1999年   50980篇
  1998年   12467篇
  1997年   11012篇
  1996年   11032篇
  1995年   10331篇
  1994年   9357篇
  1993年   8868篇
  1992年   37812篇
  1991年   36295篇
  1990年   35757篇
  1989年   34303篇
  1988年   30879篇
  1987年   30003篇
  1986年   28239篇
  1985年   26469篇
  1984年   19202篇
  1983年   16128篇
  1982年   8827篇
  1979年   17034篇
  1978年   11408篇
  1977年   10232篇
  1976年   8840篇
  1975年   10075篇
  1974年   11656篇
  1973年   11281篇
  1972年   10754篇
  1971年   10093篇
  1970年   9252篇
  1969年   8938篇
  1968年   7920篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
113.
The aim of this study was to determine whether patients with sickle cell disease (SCD) in steady state had pulmonary abnormalities seen on high-resolution computed tomography (HRCT) and whether any abnormalities correlated with contemporaneously diagnosed lung function abnormalities. A subsidiary question was whether the results of a noninvasive measure of haemolysis (end-tidal carbon monoxide (ETCO) levels) correlated with pulmonary function abnormalities. Thirty three patients with SCD, median (range) age 36 yrs (17-67 yrs) were examined. The degree of lobar volume loss and ground-glass opacification and prominence of central vessels on HRCT were quantitatively assessed. Pulmonary function was assessed by measurements of lung volumes, spirometry, gas transfer and oxygen saturation. ETCO levels were measured using an end-tidal CO monitor. Forced expiratory volume in one second (FEV1), forced vital capacity and total lung capacity significantly correlated with HRCT findings, particularly lobar volume loss. ETCO levels significantly negatively correlated with FEV1, vital capacity measured using a plethysmograph, specific airway conductance and arterial oxygen saturation measured by pulse oxymetry. In conclusion, the present results suggest that high-resolution computed tomography noninvasive assessment of haemolysis might be useful to identify sickle cell disease patients with respiratory function impairment.  相似文献   
114.
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders.  相似文献   
115.
116.
117.
Vacuum-assisted closure (VAC), although a modern adjunct in wound management, has not been used previously in pyoderma gangrenosum (PG), probably to avoid the potential complications of ‘pathergy’. We would like to report our experience of VAC in three cases of PG with the relevant review of literature.  相似文献   
118.
The aim of this study was to examine the predictors of long-term survival (>24 months) in patients with gall bladder cancer. A retrospective review of 117 cases of gall bladder cancer resected between 1989 and 2000. The resections included 80 simple cholecystectomies and 37 extended procedures. Patients with survival >24 months (n=44) were compared with those having survival <24 months (n=73) for 17 prognostic factors. Overall median survival was 16 months with a 5-year survival of 27%. T status (P=.000) and adjuvant chemoradiotherapy (P=.001) were independent predictors of long-term survival. Survival advantage was seen in T3N+ve disease (P=.007) with extended procedures. Complete (R0) resection was attained in 30 patients with a 5-year survival advantage of 30% as compared with incomplete (R1) resection (P=.0002). Adjuvant chemoradiotherapy improved survival in simple cholecystectomy group (P=.0008) but no advantage was seen after extended procedures. Stage III (P=.001) and node-positive disease (P=.0005) had significant benefit with adjuvant therapy. Poor differentiation and vascular invasion were associated with poor long-term survival. R0 resection was associated with prolonged survival. Extended procedures improved survival in patients with T3N+ve disease. Addition of chemoradiotherapy made significant improvement in long-term survival in stage III and node-positive lesions and in patients undergoing simple cholecystectomy. R0 resection predicted long-term survival in gall bladder cancer. T3 N+ve disease had better survival after extended procedures. Adjuvant chemoradiotherapy improved survival in stage III and node-positive disease. Poor differentiation and vascular invasion were adverse predictors of survival.  相似文献   
119.
Herniography has been used for 25 years in the diagnosis of occult herniation but has not gained widespread acceptance in the UK, despite studies confirming its high sensitivity and specificity for occult hernias and an excellent record of safety and patient acceptability. The traditional approach in the UK to suspected occult groin herniation has been surgical exploration. This study examined the use of herniography in a single district general hospital to assess its impact in limiting unnecessary groin explorations and allowing discharge of patients without hernias. The case notes of 90 successive patients referred for herniography by the department of general surgery in a single UK district general hospital over an 18-month period were reviewed. Eighty-seven completed examinations were analysed in which 23 hernias were diagnosed in 20 patients. Thirteen patients have undergone hernia repair with resolution of symptoms. There were no false positive examinations, although two inguinal hernias were incorrectly diagnosed radiologically as femoral hernias; there were two false negative examinations where additional hernias were found at laparoscopic repair. There were no reported complications. Twenty-four patients were discharged directly from the surgical clinic after a negative herniogram. Thirty patients were referred to other specialities. No patient had undergone groin exploration after a negative herniogram. Herniography is a useful tool in assessing obscure groin pain and potential occult herniation. It can reliably rule out the presence of a hernia and avoid the need for surgical exploration. Many patients with a negative herniogram can be reassured and discharged, whilst others may be referred on to other specialities safe in the knowledge that an occult hernia has been excluded.  相似文献   
120.
灾难的时代错误:灾害医学的过去、现在和将来(一)   总被引:1,自引:0,他引:1  
灾难,特别是地震、火山、洪水以及与战争有关的事件如饥饿和流行性传染病,是人类有记录的经历的一部分。从意大利庞贝的火山爆发,到约翰斯顿的洪水、第二次世界大战和黑色瘟疫,到西班牙流感,都发生了灾难,这不会被传说和历史书籍长期忘却。不过,在20世纪中叶以前,那些灾难的发生相对较少,且相距时间较长。从20世纪中叶以来,灾难的本质发生了变化。从恐怖分子使用“新技术”,到与气候有关的导致亿万美元经济损失的事件,表明这个世界正在发生变化。仅仅在最近的50~60年间,造成多种多样的伤亡事件,其危险性和频率的增加引人注目,并且注定要在接…  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