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   46447篇
  免费   5387篇
  国内免费   191篇
耳鼻咽喉   674篇
儿科学   1547篇
妇产科学   747篇
基础医学   5007篇
口腔科学   566篇
临床医学   5226篇
内科学   10702篇
皮肤病学   1101篇
神经病学   4460篇
特种医学   1845篇
外科学   9173篇
综合类   353篇
一般理论   81篇
预防医学   3519篇
眼科学   1631篇
药学   2197篇
中国医学   39篇
肿瘤学   3157篇
  2023年   991篇
  2022年   347篇
  2021年   1642篇
  2020年   1133篇
  2019年   1428篇
  2018年   2168篇
  2017年   1741篇
  2016年   1756篇
  2015年   1794篇
  2014年   2473篇
  2013年   2716篇
  2012年   3748篇
  2011年   3712篇
  2010年   2327篇
  2009年   2295篇
  2008年   3028篇
  2007年   2839篇
  2006年   2798篇
  2005年   2581篇
  2004年   2493篇
  2003年   2078篇
  2002年   1924篇
  2001年   339篇
  2000年   210篇
  1999年   297篇
  1998年   393篇
  1997年   361篇
  1996年   248篇
  1995年   277篇
  1994年   200篇
  1993年   194篇
  1992年   143篇
  1991年   139篇
  1990年   99篇
  1989年   92篇
  1988年   70篇
  1987年   73篇
  1986年   69篇
  1985年   64篇
  1984年   78篇
  1983年   92篇
  1982年   114篇
  1981年   84篇
  1980年   59篇
  1979年   29篇
  1978年   34篇
  1977年   36篇
  1976年   21篇
  1973年   22篇
  1972年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Gastrostomy tube placement is a procedure that achieves enteral access for nutrition, decompression, and medication administration. Preprocedural evaluation and selection of patients is necessary to provide optimal benefit and reduce the risk of adverse events (AEs). Appropriate indications, contraindications, ethical considerations, and comorbidities of patients referred for gastrostomy placement should be weighed and balanced. Additionally, endoscopist should consider either a transoral or transabdominal approach is appropriate, and radiologic or surgical gastrostomy tube placement is needed. However, medical history, physical examination, and imaging prior to the procedure should be considered to tailor the appropriate approach and reduce the risk of AEs.  相似文献   
2.
3.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  相似文献   
4.

Background

Esophagectomy is a major surgical intervention and a cornerstone in the treatment of esophageal cancer. There is clinical experience that blood lactate concentration often is elevated in the period following esophagectomy, but the incidence and clinical consequences are sparsely studied.

Methods

We extracted data from all patients undergoing esophagectomy at Karolinska University Hospital 2016–2018, n = 153. Most were performed with minimally invasive technique, n = 130. Blood lactate values directly after surgery, highest value during the first night, and morning level on postoperative day one were recorded. Primary outcome was hospital length of stay and secondary outcome was a composite of postoperative infection, additional surgery, or intensive care during the hospital stay. Development of anastomotic leak was analyzed separately.

Results

Postoperative hyperlactatemia was common as 93% of patients had peak lactate concentration >1.6 mmol/L and 27% >3.5 mmol/L in the first night following operation. Median hospital length of stay was 14 days. Blood lactate showed a weak correlation to hospital stay and intensive care the morning following surgery, but not at arrival to postoperative ward. There were no statistical differences between those with and without anastomotic leak at any of the time points. Elevated lactate in the first 12–16 h postoperatively was related to surgical factors (open technique, surgery time, and perioperative bleeding) but not to patient related factors (ASA-class, Charlson comorbidity index, sex, age) or cumulative fluid balance.

Conclusion

In conclusion, elevated blood lactate in the immediate time following esophagectomy showed a weak association to intensive care and length of stay but not anastomotic leak.  相似文献   
5.
6.
7.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
8.
9.
10.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.  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