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   66014篇
  免费   5037篇
  国内免费   276篇
耳鼻咽喉   813篇
儿科学   1848篇
妇产科学   1233篇
基础医学   8527篇
口腔科学   1056篇
临床医学   7132篇
内科学   14996篇
皮肤病学   1154篇
神经病学   6608篇
特种医学   2411篇
外国民族医学   2篇
外科学   10602篇
综合类   458篇
一般理论   47篇
预防医学   4780篇
眼科学   855篇
药学   3821篇
中国医学   109篇
肿瘤学   4875篇
  2023年   314篇
  2022年   616篇
  2021年   1414篇
  2020年   986篇
  2019年   1693篇
  2018年   1976篇
  2017年   1499篇
  2016年   1514篇
  2015年   1853篇
  2014年   2516篇
  2013年   3442篇
  2012年   4582篇
  2011年   4968篇
  2010年   2972篇
  2009年   2786篇
  2008年   4306篇
  2007年   4518篇
  2006年   4285篇
  2005年   4255篇
  2004年   3946篇
  2003年   3835篇
  2002年   3696篇
  2001年   570篇
  2000年   419篇
  1999年   544篇
  1998年   770篇
  1997年   657篇
  1996年   502篇
  1995年   539篇
  1994年   437篇
  1993年   418篇
  1992年   269篇
  1991年   298篇
  1990年   247篇
  1989年   211篇
  1988年   208篇
  1987年   210篇
  1986年   201篇
  1985年   200篇
  1984年   239篇
  1983年   204篇
  1982年   257篇
  1981年   250篇
  1980年   218篇
  1979年   132篇
  1978年   138篇
  1977年   118篇
  1976年   94篇
  1975年   88篇
  1972年   83篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.

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   
23.
Sagging eyelid is considered as an outward of skin ageing and may cause medical issues. However, little is known about the factors involved in sagging eyelid. The study, which aims at determining genetic risk factors for eyelid sagging, was conducted in a cohort of 502 unrelated Caucasian women living in the Paris region. All included participants were aged between 44 and 70 years old (mean age, 57.6 years old). The severity of sagging eyelid was graded in 6 categories by a dermatologist using standardized photographs of the face. A genome wide association study adjusted on potential risk factors (including age and smoking habits) was conducted to identify genetic associations. Two single nucleotide polymorphisms in total linkage disequilibrium on chromosome 10, rs16927253 (P = 7.07 × 10‐10) and rs4746957 (P = 1.06 × 10‐8), were significantly associated with eyelid sagging severity. The rs16927253‐T and rs4746957‐A alleles showed a dominant protective effect towards eyelid sagging. These polymorphisms are located in intronic parts of the H2AFY2 gene which encodes a member of the H2A histone family and very close to the AIFM2 gene that induces apoptosis. Additionally, single nucleotide polymorphisms with a false discovery rate below 0.25 were located nearby the type XIII collagen COL13A1 gene on chromosome 10 and in the ADAMTS18 gene on chromosome 16. Several relevant genes were identified by the genome wide association study for their potential role in the sagging eyelid severity.  相似文献   
24.
25.
26.
27.
28.
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer.  相似文献   
29.
30.
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