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   165785篇
  免费   8778篇
  国内免费   141篇
耳鼻咽喉   2700篇
儿科学   5472篇
妇产科学   3733篇
基础医学   26007篇
口腔科学   5041篇
临床医学   13631篇
内科学   30125篇
皮肤病学   4664篇
神经病学   17430篇
特种医学   7088篇
外国民族医学   2篇
外科学   25419篇
综合类   710篇
一般理论   46篇
预防医学   8922篇
眼科学   3443篇
药学   11439篇
中国医学   243篇
肿瘤学   8589篇
  2023年   899篇
  2022年   703篇
  2021年   1609篇
  2020年   1462篇
  2019年   1779篇
  2018年   3307篇
  2017年   2864篇
  2016年   3728篇
  2015年   3341篇
  2014年   3785篇
  2013年   6373篇
  2012年   8236篇
  2011年   9110篇
  2010年   5198篇
  2009年   3775篇
  2008年   9052篇
  2007年   9473篇
  2006年   9170篇
  2005年   9098篇
  2004年   8604篇
  2003年   8745篇
  2002年   8637篇
  2001年   6331篇
  2000年   7750篇
  1999年   4692篇
  1998年   1898篇
  1997年   1538篇
  1996年   1231篇
  1995年   1023篇
  1994年   1000篇
  1993年   933篇
  1992年   1306篇
  1991年   1204篇
  1990年   1194篇
  1989年   1179篇
  1988年   999篇
  1987年   1074篇
  1986年   937篇
  1985年   1145篇
  1984年   1015篇
  1983年   866篇
  1982年   781篇
  1981年   743篇
  1980年   681篇
  1979年   806篇
  1978年   677篇
  1977年   672篇
  1976年   553篇
  1975年   620篇
  1974年   570篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.

Background

Hyperglycaemia is common in patients with acute brain injury admitted to an intensive care unit (ICU). Many studies have found associations between development of hyperglycaemia and increased mortality in hospitalised patients. However, the optimal target for blood glucose control is unknown. We want to conduct a systematic review with meta-analysis and trial sequential analysis to explore the beneficial and harmful effects of restrictive versus liberal glucose control on patient outcomes in adults with severe acute brain injury.

Methods

We will systematically search medical databases including CENTRAL, Embase, MEDLINE and trial registries. We will search the following websites for ongoing or unpublished trials: http://www.controlled-trials.com/ , http://www.clinicaltrials.gov/ , www.eudraCT.com , http://centerwatch.com/ , The Cochrane Library's CENTRAL, PubMed, EMBASE, Science Citation Index Expanded and CINAHL. Two authors will independently review and select trials and extract data. We will include randomised trials comparing levels of glucose control in our analyses and observational studies will be included to address potential harms. The primary outcomes are defined as all-cause mortality, functional outcome and health-related quality of life. Secondary outcomes include serious adverse events including hypoglycaemia, length of ICU stay and duration of mechanical ventilation, and explorative outcomes including intracranial pressure and infection. Trial Sequential Analysis will be used to investigate the risk of type I error due to repetitive testing and to further explore imprecision. Quality of trials will be evaluated using the Cochrane Risk of Bias tool, and quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

Discussion

The results of the systematic review will be disseminated through peer-reviewed publication. With the review, we hope to inform future randomised clinical trials and improve clinical practice.  相似文献   
4.
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.  相似文献   
5.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  相似文献   
6.
7.
8.
9.
10.
Sorsby fundus dystrophy (SFD), an autosomal dominant, fully penetrant, degenerative disease of the macula, is manifested by symptoms of night blindness or sudden loss of visual acuity, usually in the third to fourth decades of life due to choroidal neovascularization (CNV). SFD is caused by specific mutations in the Tissue Inhibitor of Metalloproteinase-3, (TIMP3) gene. The predominant histo-pathological feature in the eyes of patients with SFD are confluent 20–30 m thick, amorphous deposits found between the basement membrane of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. SFD is a rare disease but it has generated significant interest because it closely resembles the exudative or “wet” form of the more common age-related macular degeneration (AMD). In addition, in both SFD and AMD donor eyes, sub-retinal deposits have been shown to accumulate TIMP3 protein. Understanding the molecular functions of wild-type and mutant TIMP3 will provide significant insights into the patho-physiology of SFD and perhaps AMD. This review summarizes the current knowledge on TIMP3 and how mutations in TIMP3 cause SFD to provide insights into how we can study this disease going forward. Findings from these studies could have potential therapeutic implications for both SFD and AMD.  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