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   1291970篇
  免费   91512篇
  国内免费   1965篇
耳鼻咽喉   18539篇
儿科学   44502篇
妇产科学   35085篇
基础医学   183016篇
口腔科学   33688篇
临床医学   112030篇
内科学   259578篇
皮肤病学   28070篇
神经病学   101149篇
特种医学   51376篇
外国民族医学   660篇
外科学   197307篇
综合类   27082篇
现状与发展   1篇
一般理论   380篇
预防医学   96109篇
眼科学   28134篇
药学   95261篇
  31篇
中国医学   2426篇
肿瘤学   71023篇
  2018年   13253篇
  2017年   10099篇
  2016年   11039篇
  2015年   12429篇
  2014年   17271篇
  2013年   26352篇
  2012年   36233篇
  2011年   38282篇
  2010年   22907篇
  2009年   21937篇
  2008年   36829篇
  2007年   39429篇
  2006年   39715篇
  2005年   38643篇
  2004年   37758篇
  2003年   36591篇
  2002年   35939篇
  2001年   64098篇
  2000年   66613篇
  1999年   56496篇
  1998年   15171篇
  1997年   13792篇
  1996年   14234篇
  1995年   13484篇
  1994年   12800篇
  1993年   11827篇
  1992年   44671篇
  1991年   43564篇
  1990年   42336篇
  1989年   40219篇
  1988年   37009篇
  1987年   36340篇
  1986年   33717篇
  1985年   32384篇
  1984年   24220篇
  1983年   20343篇
  1982年   11773篇
  1981年   10741篇
  1980年   9559篇
  1979年   21415篇
  1978年   14889篇
  1977年   12601篇
  1976年   11747篇
  1975年   12669篇
  1974年   14726篇
  1973年   14175篇
  1972年   12981篇
  1971年   11767篇
  1970年   11099篇
  1969年   10067篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
The community pharmacy setting is a venue that is readily accessible to the public. In addition, it is staffed by a pharmacist, who is a healthcare provider, trained and capable of delivering comprehensive pharmaceutical care. As such, community pharmacists have a colossal opportunity to serve as key contributors to patients’ health by ensuring appropriate use of medications, preventing medication misadventures, identifying drug-therapy needs, as well as by being involved in disease management, screening, and prevention programs. This unique position gives the pharmacist the privilege and duty to serve patients in roles other than solely that of the stereotypical drug dispenser.Worldwide, as well as in Israel, pharmacists already offer a variety of pharmaceutical services and tend to patients’ and the healthcare system’s needs. This article provides examples of professional, clinical or other specialty services offered by community pharmacists around the world and in Israel and describes these interventions as well as the evidence for their efficacy. Examples of such activities which were recently introduced to the Israeli pharmacy landscape due to legislative changes which expanded the pharmacist’s scope of practice include emergency supply of medications, pharmacists prescribing, and influenza vaccination. Despite the progress already made, further expansion of these opportunities is warranted but challenging. Independent prescribing, as practiced in the United Kingdom or collaborative drug therapy management programs, as practiced in the United States, expansion of vaccination programs, or wide-spread recognition and reimbursement for medication therapy management (MTM) programs are unrealized opportunities. Obstacles such as time constraints, lack of financial incentives, inadequate facilities and technology, and lack of professional buy-in, and suggested means for overcoming these challenges are also discussed.  相似文献   
43.
The predominant use of glucose anaerobically by cancer cells (Warburg effect) may be the most important characteristic the majority of these cells have in common and, therefore, a potential metabolic pathway to be targeted during cancer treatment. Because this effect relates to fuel oxidation, dietary manipulation has been hypothesized as an important strategy during cancer treatment. As such, the concept of a ketogenic diet (KD) in cancer emerged as a metabolic therapy (ie, targeting cancer cell metabolism) rather than a dietary approach. The therapeutic mechanisms of action of this high-fat, moderate-to-low protein, and very-low-carbohydrate diet may potentially influence cancer treatment and prognosis. Considering the lack of a dietetics-focused narrative review on this topic, we compiled the evidence related to the use of this diet in humans with diverse cancer types and stages, also focusing on the nutrition and health perspective. The use of KD in cancer shows potentially promising, but inconsistent, results. The limited number of studies and differences in study design and characteristics contribute to overall poor quality evidence, limiting the ability to draw evidence-based conclusions. However, the potential positive influences a KD may have on cancer treatment justify the need for well-designed clinical trials to better elucidate the mechanisms by which this dietary approach affects nutritional status, cancer prognosis, and overall health. The role of registered dietitian nutritionists is demonstrated to be crucial in planning and implementing KD protocols in oncology research settings, while also ensuring patients’ adherence and optimal nutritional status.  相似文献   
44.
The utility of empirical combination antimicrobial therapy for Gram-negative bloodstream infection (BSI) remains unclear. This retrospective, quasi-experimental matched cohort study examined the impact of empirical combination therapy on mortality in patients with Gram-negative BSI. Hospitalized adults with Gram-negative BSI from 1 January 2010 to 31 December 2013 at Palmetto Health Hospitals in Columbia, SC, USA were identified. Patients receiving combination therapy or beta-lactam monotherapy were matched 1:1 based on age, sex and Bloodstream Infection Mortality Risk Score (BSIMRS). Multivariate Cox proportional hazards regression with propensity score adjustment was used to examine overall 28–day mortality and within predefined BSIMRS categories (<5 and ≥5). A total of 380 patients receiving combination therapy or monotherapy for Gram-negative BSI were included in the study. Median age was 66 years and 204 (54%) were female. Overall, 28-day mortality in patients who received combination therapy and monotherapy was 13% and 15%, respectively (P?=?0.51). After stratification by BSIMRS, mortality in both combination therapy and monotherapy groups was 1.1% in patients with BSIMRS <5 (P?=?0.98) and 27% and 32%, respectively, in patients with BSIMRS ≥5 (P?=?0.47). After adjusting for propensity to receive combination therapy, risk of mortality was not significantly different for combination therapy compared to monotherapy (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.51–1.60). This finding persisted for both subgroups of BSIMRS <5 (HR 0.96, 95% CI 0.04–24.28) and BSIMRS ≥5 (HR 0.83, 95% CI 0.46–1.48). There is no survival benefit from empirical combination therapy over monotherapy in patients with Gram-negative BSI, regardless of predicted prognosis at initial presentation.  相似文献   
45.
46.
47.
中文:背景患者入院后可从不当消毒的环境表面获得多药耐药菌和艰难梭菌。本文确定了3种强化的终末消毒(入住同一病房的两名患者之间的消毒)策略,对感染耐甲氧西林金黄色葡萄球菌(MRSA)、耐万古霉素肠球菌(VRE)、艰难梭菌(CD)和多重耐药不动杆菌的影响。方法本文在美国东南部的9家医院开展了一项务实的、集群-随机、交叉研究。凡曾有感染或定植目标细菌感染患者居住过的病房,患者出院后随机采取4种消毒策略中的一种方法进行终末消毒:对照(季胺盐类消毒剂消毒,但凡遇到CD采用含氯消毒剂);UV(季胺盐类+UV-C消毒,但凡遇到CD采用含氯消毒剂+UV-C);含氯消毒剂;含氯消毒剂+UV-C。凡入住目标病房的患者被列为暴露人群。这4种终末消毒方法分别在每家医院连续实施7个月的周期。本文随机设计这几种消毒策略在每家医院内的实施顺序(1:1:1:1)。主要产出的结果是,观察暴露患者中目标细菌的感染的发生或定植情况,以及ITT人群中暴露患者CD感染发生率。本研究ClinicalTrials.gov注册编号:NCT01579370。结果共有31 226名患者暴露,其中21 395(69%)符合标准,包括4 916名对照组,5 178名UV组,5 438名含氯消毒剂组,以及5 863名含氯消毒剂+UV组。在对照组中,22 426个暴露日中有115名患者发生目标细菌的感染(51.3/10000暴露日)。在标准清洁策略的基础上增加UV消毒的暴露患者,其目标细菌感染的发生率明显较低(n=76;33.9/10 000暴露日;RR:0.70,95%CI:0.50~0.988;P=0.036)。含氯消毒剂组(n=101;41.6/10 000暴露日;RR:0.85,95%CI:0.69~1.04;P=0.116),或含氯消毒剂+UV组患者(n=131;45.6/10 000暴露日;RR:0.91,95%CI:0.76~1.09;P=0.303)的目标细菌的感染率,其差异无统计学意义。同样,在含氯消毒剂的基础上增加UV消毒,暴露患者中CD感染率也没有发生改变((n=38 vs 36;30.4 vs 31.6/10 000暴露日;RR:1.0,95%CI:0.57-1.75;P=0.997)。解释污染的医疗机构环境是获得病原微生物的重要来源;强化终末消毒可以降低这一风险。  相似文献   
48.
Genetically informative designs and, in particular, twin studies, are the most widely used methodology to analyse the relative contribution of genetic and environmental factors to inter-individual variability. These studies basically compare the degree of phenotypical similarity between monozygotic and dizygotic twin pairs. In addition to the traditional estimate of heritability, this kind of registry enables a wide variety of analyses which are unique due to the characteristics of the sample. The Murcia Twin Registry is population-based and focused on the analysis of health-related behaviour. The observed prevalence of health problems is comparable to that of other regional and national reference samples, which guarantees its representativeness. Overall, the characteristics of the Registry facilitate developing various types of research as well as genetically informative designs, and collaboration with different initiatives and consortia.  相似文献   
49.
50.
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