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   536篇
  免费   23篇
  国内免费   1篇
耳鼻咽喉   6篇
儿科学   11篇
妇产科学   16篇
基础医学   49篇
口腔科学   8篇
临床医学   52篇
内科学   144篇
神经病学   29篇
特种医学   26篇
外科学   61篇
综合类   35篇
预防医学   41篇
眼科学   6篇
药学   42篇
  1篇
中国医学   2篇
肿瘤学   31篇
  2023年   8篇
  2022年   11篇
  2021年   24篇
  2020年   7篇
  2019年   14篇
  2018年   23篇
  2017年   9篇
  2016年   13篇
  2015年   17篇
  2014年   15篇
  2013年   32篇
  2012年   33篇
  2011年   34篇
  2010年   17篇
  2009年   11篇
  2008年   19篇
  2007年   27篇
  2006年   24篇
  2005年   21篇
  2004年   25篇
  2003年   21篇
  2002年   22篇
  2001年   9篇
  2000年   19篇
  1999年   17篇
  1998年   10篇
  1997年   5篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   9篇
  1991年   7篇
  1990年   5篇
  1989年   8篇
  1988年   9篇
  1987年   5篇
  1986年   6篇
  1985年   4篇
  1984年   4篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1975年   1篇
  1966年   1篇
排序方式: 共有560条查询结果,搜索用时 15 毫秒
41.
This study examined the sociodemographic correlates of psychiatric illness in a primary care centre in Kuwait. A total of 164 psychiatric patients seen over a 3-year period formed the experimental group while 165 nonpsychiatric patients attending the same centre formed the control group. Results showed significant differences in basic demographic variables of the 2 groups. The psychiatric patients were significantly more likely to be single, unskilled, young, less educated and living alone or in an overcrowded household and to report more recent life events than controls. The absence of family and social support, lacking a meaningful job and chronicity of illness were significantly correlated with poor treatment response. Possible interpretations of the results were discussed in the cultural context of our patients. The fact that 57% of the psychiatric patients had been ill for more than 6 months prior to consultation highlights the importance of orientation of primary care practitioners to the psychiatric aetiology of somatic presentation of many of their patients.  相似文献   
42.
Chronic fatigue syndrome: physical and cardiovascular deconditioning   总被引:2,自引:0,他引:2  
We investigated whether chronic fatigue syndrome (CFS) patients have physical and/or cardiovascular de-conditioning, in 273 CFS patients and 72 healthy controls. We used laboratory tests to assess haematological, biochemical, endocrinological and immunological systems. The cardiovascular system was assessed by echocardiography and carotid echography. Body composition was determined by dual energy X-ray absorptiometry (DEXA). CFS patients had smaller left ventricular end systolic (p < 0.001) and diastolic (p = 0.008) dimensions but thinner posterior walls (p = 0.02) than corresponding values in healthy controls. Left ventricular mass was also reduced in CFS patients (p = 0.006). Both maximum (p < 0.001) and minimum (p < 0.008) diameter of the carotid artery were smaller in CFS patients. The laboratory screening tests showed significant differences in serum albumin (p = 0.05), phosphate (p = 0.02), HDL-cholesterol (p = 0.03), HDL:total cholesterol ratio (p = 0.01), triglycerides (p = 0.02), neutrophils (p = 0.01) and thyroid-stimulating hormone (p = 0.04) between CFS patients and controls. Male CFS patients had an increased percentage of fat mass compared with healthy male subjects (p = 0.02). This large group of CFS patients had evidence of physical and cardiovascular de-conditioning, suggesting that in these patients a graded exercise programme could lead to physical reconditioning and could increase their ability to perform physical activities.   相似文献   
43.
Calcified amorphous tumors (CAT) of the heart are rare primary cardiac tumors characterized by heavy myocardial and valve apparatus calcification. The relationship of the entity with ventricular arrhythmia, if any, is unknown. We describe a case of cardiac CAT in a 58-year-old woman with prior cardiac arrest and recurrent ventricular tachycardia who presented for radiofrequency ablation. Pre-ablation intracardiac echocardiogram revealed the characteristic endomyocardial calcific pattern associated with this tumor that precluded catheter manipulation in the left ventricle. The imaging characteristics and management are described.  相似文献   
44.
BACKGROUND AND AIM OF THE STUDy: Long-term echocardiographic follow up studies of mitral balloon valvuloplasty (MBV) are scarce. The study aim was to assess the long-term results (up to 17 years) of MBV and to identify predictors of restenosis and event-free survival. METHODS: The immediate and long-term clinical and echocardiographic results for 520 consecutive patients (mean age 31 +/- 11 years) who underwent successful MBV for severe mitral stenosis (MS) and were followed up for a mean of 7.3 +/- 4.35 years (range: 1 to 17 years) after MBV, were reported. RESULTS: Immediately after MBV, the mitral valve area (MVA) was increased from 0.92 +/- 0.17 to 1.96 +/- 0.29 cm2 (p < 0.0001). Restenosis occurred in 133 patients (25.6%), and was less frequent (16.7%) in patients with a low mitral echo score (MES < or = 8). Actuarial freedom from restenosis at 10, 15, and 17 years was 73 +/- 2%, 43 +/- 4%, and 23 +/- 6%, respectively, and was significantly higher in patients with MES < or = 8 (84 +/- 2%, 52 +/- 6%, and 36 +/- 9%, respectively; p < 0.001). Event-free survival (death, redo MBV, mitral valve replacement, NYHA class III or IV) at 10, 15, and 17 years was 82 +/- 2%, 45 +/- 5%, and 31 +/- 6% respectively, and was significantly higher for patients with MES < or = 8 (90 +/- 2%, 60 +/- 5%, and 51 +/- 8%, respectively; p < 0.001). Cox regression analysis identified MES > 8 (p < 0.0001) and post-procedure MVA (p = 0.044) as predictors of restenosis, and MES < or = 8 (p < 0.0001), age (p < 0.0001), and post-procedure MVA (p = 0.016) as predictors of event-free survival. CONCLUSION: MBV provides excellent long-term results for selected patients with MS. The long-term outcome of this procedure can be predicted from the baseline clinical and echocardiographic characteristics of the mitral valve.  相似文献   
45.
46.
47.
Low-energy femoral shaft fractures associated with alendronate use   总被引:4,自引:0,他引:4  
OBJECTIVE: Increasing evidence suggests long-term alendronate use may overly suppress bone metabolism, limiting repair of microdamage and creating risk for insufficiency fractures. The purpose of this study is to demonstrate an association between alendronate use and a specific pattern of low-energy femoral shaft fracture. DESIGN, SETTING, AND PATIENTS: A retrospective review was performed of patients with femoral shaft fractures admitted to a Level 1 trauma center between January 2002 and March 2007. Seventy low-energy fractures were identified. MAIN OUTCOME MEASURE: The medical records were reviewed, and the incidence and duration of alendronate use were recorded. The incidence of a specific femoral shaft fracture in those patients taking alendronate compared with those not being treated was determined. RESULTS: There were 59 females and 11 males. The average age was 74.7 years. Twenty-five (36%) were being treated with alendronate. None of the patients had used or were using other bisphosphonates. Nineteen (76%) of these 25 patients demonstrated a simple, transverse fracture with a unicortical beak in an area of cortical hypertrophy. This fracture pattern was seen in only 1 patient (2%) not being treated with alendronate. Alendronate use was a significant risk factor for the fracture pattern (odds ratio [OR]) 139.33, 95% CI [19.0-939.4], P < 0.0001). This pattern was 98% specific to alendronate users. The average duration of alendronate use in those with the pattern was significantly longer than those who did not exhibit the pattern but were taking alendronate, 6.9 years versus 2.5 years of use, respectively (P = 0.002). Only 1 patient with the fracture pattern had been taking alendronate for less than 4 years. CONCLUSIONS: Low-energy fractures of the femoral shaft with a simple, transverse pattern and hypertrophy of the diaphyseal cortex are associated with alendronate use. This may result from propagation of a stress fracture whose repair is retarded by diminished osteoclast activity and impaired microdamage repair resulting from its prolonged use.  相似文献   
48.
49.
Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease. Ezetimibe is the first member of a new class of selective cholesterol absorption inhibitors. It impairs the intestinal reabsorption of both dietary and hepatically excreted biliary cholesterol. Ezetimibe is an effective and safe agent for lowering LDL-C and non HDL-C. Short term clinical trials have established the role of ezetimibe monotherapy and its use in combination with statins. Furthermore, ezetimibe and statin combination therapy increased the percentage of patients who achieved their LDL-C treatment goal.  相似文献   
50.
A survey of 523 facilities performing radiographic lumbosacral spine examinations was conducted as a part of the Nationwide Evaluation of X-Ray Trends program in 1987 and 1989. Average patient radiation exposure was measured by using a standard phantom developed by the Center for Devices and Radiological Health of the Food and Drug Administration, U.S. Public Health Service. Data pertaining to radiographic equipment, film processing, and radiographic techniques were obtained. The overall average entrance skin air kerma was 3.65 mGy (420 mR). Ninety-eight percent (496 of 506) of observed facilities used a grid, 89% (466 of 523) had tube potentials between 70 and 89 kVp, and 67% (280 of 418) used screen-film systems with a speed of 400. The most important finding is that underprocessing of film remains a major concern. Thirty-three percent (78 of 234) of the hospitals, 25% of the radiologists in private practice (four of 16), 33% of the nonradiologist private practitioners (27 of 82), and 48% (69 of 143) of the chiropractors underprocessed their film.  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