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   3030篇
  免费   143篇
  国内免费   19篇
耳鼻咽喉   78篇
儿科学   173篇
妇产科学   210篇
基础医学   229篇
口腔科学   75篇
临床医学   250篇
内科学   779篇
皮肤病学   61篇
神经病学   182篇
特种医学   134篇
外科学   603篇
综合类   40篇
一般理论   3篇
预防医学   68篇
眼科学   98篇
药学   111篇
中国医学   3篇
肿瘤学   95篇
  2024年   2篇
  2023年   36篇
  2022年   47篇
  2021年   89篇
  2020年   67篇
  2019年   74篇
  2018年   98篇
  2017年   80篇
  2016年   126篇
  2015年   149篇
  2014年   159篇
  2013年   188篇
  2012年   233篇
  2011年   167篇
  2010年   141篇
  2009年   127篇
  2008年   175篇
  2007年   223篇
  2006年   205篇
  2005年   212篇
  2004年   175篇
  2003年   129篇
  2002年   109篇
  2001年   53篇
  2000年   43篇
  1999年   40篇
  1998年   8篇
  1997年   4篇
  1996年   6篇
  1995年   5篇
  1994年   3篇
  1993年   1篇
  1992年   3篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1969年   1篇
排序方式: 共有3192条查询结果,搜索用时 15 毫秒
61.
62.
The home-based exercise therapy recommended to the patients with ankylosing spondylitis (AS) is a simply applicable and cheap method. The aim of this study was to investigate the effects of home-based exercise therapy on pain, mobility, function, disease activity, quality of life, and respiratory functions in patients with AS. Eighty patients diagnosed with AS according to the modified New York criteria were included in the study. Home-based exercise program including range of motion, stretching, strengthening, posture, and respiratory exercises was practically demonstrated by a physiotherapist. A training and exercise manual booklet was given to all patients. Patients following home-based exercise program five times a week at least 30 min per session (exercise group) for 3 months were compared with those exercising less than five times a week (control group). Visual analog scale pain (VASp) values at baseline were significantly higher in the exercise group. The exercise group showed improvements in VASp, tragus–wall distance, morning stiffness, finger–floor distance, modified Schober's test, chest expansion, the Bath Ankylosing Spondylitis Disease Activity Index, the Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL), forced expiratory volume in first second, and forced vital capacity at third month. There was significant difference in ASQoL scores between the two groups in favor of the exercise group at third month. Regular home-based exercise therapy should be a part of main therapy in patients with AS. Physicians should recommend that patients with AS do exercise at least five times a week at least 30 min per session.  相似文献   
63.
64.
Purpose:The aim of this study was to evaluate the structural and functional changes occurring in patients with branch retinal vein occlusion (BRVO) according to the distance of the affected arteriovenous (AV) crossing to the centers of the fovea and optic disc by optic coherence tomography angiography (OCTA).Methods:Forty-five patients with unilateral BRVO and 45 age- and sex-matched healthy controls were included in this retrospective observational study. Images of the macula (3 mm × 3 mm) and affected AV crossing sites were obtained by OCTA. The fovea-AV crossing distance (FAVD), optic disc-AV crossing distance (DAVD), and optic disc-fovea distance (DFD) were measured.Results:The FAVD/DFD ratio was positively correlated with the vessel density in the superficial and deep affected hemifields (r = 0.430, P < 0.05 and r = 0.308, P < 0.05, respectively) and negatively correlated with the superficial foveal avascular zone and logarithm of the minimum angle of resolution (logMAR) visual acuity (r = –0.412, P < 0.05 and r = –0.356, P < 0.05, respectively). The DAVD/DFD ratio was not correlated with the logMAR visual acuity, superficial FAZ area or vessel densities in the affected hemifield (all P > 0.05).Conclusion:The affected AV crossing site that was further away from the fovea had better visual acuity and quantitative microvascular parameters in the affected hemifields. However, this correlation was not observed for the distance between the affected AV crossing site and the optic disc.  相似文献   
65.
Background. Insulin resistance was an independent predictor of cardiovascular mortality in uremic patients without diabetes. Rosiglitazone (ROS) improves insulin sensitivity in the liver, muscle, and adipose tissue. We prospectively investigated the effects of ROS on cardiac functions by standard (SDE) and tissue Doppler echocardiography (TDI) in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods. A total of 24 CAPD patients (13 males, 11 females; mean age 42.2 ± 14.8 years) were included. Routine blood samples were examined. Left and right ventricular functions were assessed, and myocardial performance index (MPI) was calculated by SDE and TDI at baseline and after 12-month ROS therapy. Left and right atrial volumes were measured and indexed to body surface area. Results. When compared with baseline, after 12 months of ROS treatment, it was shown that early (E) and late (A) diastolic velocities of atrioventricular valves, E/A ratio, mitral E-wave deceleration time (DT), isovolumetric relaxation time (IVRT), and MPI were similar (p > 0.05). Also, no significant changes were detected in LV dimensions, LV mass index, LVEF, LA volume index, or RA volume index measured by SDE before and after ROS therapy (p > 0.05). Left and right ventricular function parameters measured by TDI including Sm, Em, Am, Em/Am ratio, E/Em ratio, and MPI were similar. Conclusion. It was found that there was no negative effect of long-term ROS therapy on cardiac functions measured by SDE and TDI in CAPD patients.  相似文献   
66.

Background

Hyperactivity of the alternative complement pathway is the principle defect in C3 glomerulopathies (C3G). Eculizumab, a monoclonal antibody that binds C5 to prevent formation of the membrane attack complex, has been shown to be beneficial in some patients with this disease.

Methods

In this open-label, proof-of-concept efficacy-and-safety study, a patient with the initial diagnosis of dense deposit disease (DDD) and allograft recurrence of C3 glomerulonephritis (C3GN) was treated with eculizumab every other week for 1 year. The patient had pathological evidence of C3GN and proteinuria >1 g/day at enrollment. He underwent graft biopsy before enrollment and repeat biopsy at 6 and 12 months.

Results

Although no mutations were identified in complement genes, functional studies were positive for C3 nephritic factors and elevated levels of soluble membrane attack complex (sMAC). On therapy, sMAC levels normalized and although proteinuria initially decreased, it increased reaching pre-treatment levels at 12 months. Although serum creatinine remained stable, repeat allograft biopsies showed progression of disease.

Conclusions

Clinical and histopathologic data suggest a partial response to eculizumab in this patient. While eculizumab blocked activation of the terminal complement cascade, persistent dysregulation of the alternative pathway remained, indicating eculizumab alone cannot control disease in this patient. Additional research is required to identify effective anticomplement therapy for this group of C3G patients.  相似文献   
67.
68.

Background

The aim of the present study was to determine how lymph node ratio (LNR; the ratio of the number of metastatic lymph nodes to the number of removed lymph nodes) can supplement the TNM nodal classification in breast carcinoma.

Methods

We retrospectively reviewed the file records of 2,151 patients.

Results

Lymph node ratio-based low- (LNR ≤ 0.20), intermediate- (LNR 0.21–0.65), and high-risk (LNR > 0.65) patient groups had significantly different disease-free survival (DFS) (P < 0.001). The DFS of patients with N1, N2, and N3 disease was significantly different (P < 0.001). When LNR and TNM nodal groupings were included together in the Cox analysis, both groupings had independent prognostic significance (P < 0.001 and P < 0.001, respectively). The most significant LNR threshold value separating patients in low-risk and high-risk groups in terms of disease recurrence was 0.20 for N1 disease (P < 0.001), 0.35 for N2 disease (P < 0.001), and 0.90 for N3 disease (P < 0.001).

Conclusions

Lymph node ratio and TNM nodal groupings show no superiority over each other in categorizing patients with node-positive breast carcinoma into prognostic groups of low-, intermediate-, and high-risk. However, LNR grouping may supplement TNM nodal classification by categorizing patients within each TNM nodal group into low-risk and high-risk groups with significantly different survival.  相似文献   
69.
Background. In this study, we endeavored to determine whether the incidence of cholelithiasis (CL) was increased in chronic renal failure (CRF) patients with secondary hyperparathyroidism on a peritoneal dialysis (PD) program. We also evaluated the factors that might have some influence on the development of CL. Methods. A total of 59 CRF patients undergoing PD were included in the study. We studied the following groups to determine whether parathyroid hormone (PTH) levels were increased in CRF-PD patients: twenty patients with secondary hyperparathyroidism (group 1) and 39 patients with normal PTH levels (group 2). PTH levels were maintained at three times the upper limit of normal. Biochemical parameters were obtained for each CRF-PD patient. All patients underwent abdominal ultrasonography to screen for the presence of cholelithiasis. For statistical analysis, χ2, t test, and logistic regression analysis were used; p < 0.05 was considered as significant. Results. We found an almost ten times higher incidence (25% vs. 2.6%) of CL in group 1 patients with statistical significance (p = 0.007). When the incidence of CL according to sex, creatinine, and PTH levels were considered, female gender, creatinine, and PTH levels were higher in group 1, which was also significant statistically. No significant relationship was detected between gallbladder stone formation and the other analyzed biochemical parameters. Conclusions. We found that the incidence of CL in CRF-PD patients with secondary hyperparathyroidism was higher than CRF-PD patients with normal PTH levels. It was also detected that female gender, high creatinine levels, and elevated PTH levels might influence the development of CL in CRF-PD patients.  相似文献   
70.
We report two cases of mechanical prosthetic mitral valve obstruction caused by remnants of the mitral valve posterior leaflet tissue preserved from the previous surgery. Both patients had rheumatic mitral stenosis causing New York Heart Association class III symptoms prior to mitral valve replacement.  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