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   30986篇
  免费   2143篇
  国内免费   122篇
耳鼻咽喉   399篇
儿科学   703篇
妇产科学   581篇
基础医学   4365篇
口腔科学   1491篇
临床医学   2612篇
内科学   7486篇
皮肤病学   758篇
神经病学   2490篇
特种医学   967篇
外国民族医学   1篇
外科学   4080篇
综合类   299篇
一般理论   14篇
预防医学   2658篇
眼科学   612篇
药学   1964篇
中国医学   156篇
肿瘤学   1615篇
  2023年   222篇
  2022年   488篇
  2021年   989篇
  2020年   615篇
  2019年   870篇
  2018年   992篇
  2017年   680篇
  2016年   742篇
  2015年   840篇
  2014年   1168篇
  2013年   1509篇
  2012年   2289篇
  2011年   2371篇
  2010年   1355篇
  2009年   1127篇
  2008年   1808篇
  2007年   1931篇
  2006年   1761篇
  2005年   1665篇
  2004年   1468篇
  2003年   1343篇
  2002年   1317篇
  2001年   411篇
  2000年   395篇
  1999年   367篇
  1998年   274篇
  1997年   228篇
  1996年   223篇
  1995年   174篇
  1994年   163篇
  1993年   136篇
  1992年   188篇
  1991年   184篇
  1990年   177篇
  1989年   129篇
  1988年   142篇
  1987年   156篇
  1986年   126篇
  1985年   141篇
  1984年   154篇
  1983年   135篇
  1982年   146篇
  1981年   141篇
  1980年   128篇
  1979年   97篇
  1978年   102篇
  1977年   106篇
  1976年   78篇
  1974年   70篇
  1973年   68篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
11.
BackgroundAlthough there are robust data about the pathophysiology and prognostic implications of left ventricular (LV) systolic dysfunction in patients with acquired heart disease, similar prognostic data about LV systolic dysfunction are sparse in the tetralogy of Fallot (TOF) population. The purpose of this study was to perform a meta-analysis of all studies that assessed the relationship between LV ejection fraction (LVEF) and cardiovascular adverse events (CAEs) defined as death, aborted sudden death, or sustained ventricular tachycardia.MethodsWe used random-effects models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsOf the 1,809 citations, 7 studies with 2,854 patients (age 28 ± 4 years) were included. During 5.6 ± 3.4 years' follow-up, there were 82 deaths, 17 aborted sudden cardiac deaths, and 56 sustained ventricular tachycardia events. Overall, CAEs occurred in 5.1% (144 patients). As a continuous variable, LVEF was a predictor of CAE (HR 1.29, 95% CI, 1.09-1.53, P = 0.001) per 5% decrease in LVEF. Similarly, LVEF < 40% was also a predictor of CAE (HR 3.22, 95% CI, 2.16-4.80, P < 0.001).ConclusionsLV systolic dysfunction was an independent predictor of CAE, and we observed a 30% increase in the risk of CAE for every 5% decrease in LVEF, and a 3-fold increase in the risk of CAE in patients with LVEF <40% compared with other patients. These findings underscore the importance of incorporating LV systolic function in clinical risk stratification of patients with TOF and the need to explore new treatment options to address this problem.  相似文献   
12.
13.
14.
Trichotillomania is a form of traction alopecia resulting from repetitive and compulsive hair pulling and plucking. Trichotillomania and patchy alopecia areata may have similar clinical and dermoscopic features in some cases. On trichoscopic examination, the presence of black dots, coiled or hook hair, shafts of varying lengths with fraying or split ends (trichoptilosis), and an absence of exclamation mark hairs and yellow dots are suggestive of trichotillomania.  相似文献   
15.
Fibrous dysplasia is a non‐neoplastic developmental process that affects the craniofacial bones, characterized by painless enlargement as a result of bone substitution by abnormal fibrous tissue. Postzygotic somatic activating mutations in the GNAS1 gene cause fibrous dysplasia and have been extensively investigated, as well as being helpful in the differential diagnosis of the disease. Fibrous dysplasia may involve one (monostotic) or multiple bones (polyostotic), sporadically or in association with McCune‐Albright syndrome, Jeffe‐Lichenstein syndrome, or Mazabreud syndrome. This review summarizes the current knowledge on fibrous dysplasia, emphasizing the value of integrating the understanding of its molecular pathogenesis with the clinical, radiological, and histopathological features. In addition, we address important aspects related to the differential diagnosis and patient management.  相似文献   
16.
17.

Background Context

Long-term follow-up of patient-reported outcome measures (PROM) is essential in both modern spinal care and research. Lack of time and staff are commonly reported barriers to implementing long-term follow-up of PROM. Automated and digital follow-up systems for PROM collection are seeing widespread use, yet their validity and comparative effectiveness have never been evaluated.

Purpose

The present study aimed to assess the validity of digital follow-up systems in comparison with the conventional paper-based follow-up (PB-FU).

Study Design

This is a retrospective analysis of prospectively collected double follow-up data.

Patient Sample

Patients who underwent lumbar spinal fusion for spondylolisthesis or degenerative disc disease between 2013 and 2016 were included in the study.

Outcome Measures

The study determined the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain severity at baseline, 6 weeks, 12 months, and 24 months.

Materials and Methods

After lumbar spinal fusion surgery, a double follow-up of PROM was carried out by conventional PB-FU during clinical visits, while simultaneously completing an automatically dispatched digital follow-up questionnaire. As the primary end point, we assessed the intraindividual discrepancy in PROM between PB-FU and automated digital follow-up (AD-FU).

Results

Forty patients completed all parts of the dual follow-up trajectory and were analyzed. We detected no discrepancy in ODI or NRS for back and leg pain severity at any of the baseline, 6-week, 12-month, or 24 month follow-ups (all p>.05). This was confirmed in a sensitivity analysis.

Conclusions

In an analysis of dual paper-based and digital follow-up after lumbar fusion surgery, patients report highly similar values using either method of follow-up. It appears that AD-FU without incentives produces lower response rates. To reassess the validity of these systems for data collection in spinal patient care, a prospective validation with higher statistical power is warranted.  相似文献   
18.
19.
20.
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