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   150171篇
  免费   12101篇
  国内免费   4364篇
耳鼻咽喉   1616篇
儿科学   2772篇
妇产科学   2003篇
基础医学   8968篇
口腔科学   3243篇
临床医学   18152篇
内科学   21641篇
皮肤病学   2673篇
神经病学   8207篇
特种医学   4476篇
外国民族医学   42篇
外科学   13677篇
综合类   22963篇
现状与发展   26篇
一般理论   3篇
预防医学   8434篇
眼科学   2398篇
药学   12509篇
  107篇
中国医学   14821篇
肿瘤学   17905篇
  2024年   258篇
  2023年   2753篇
  2022年   3981篇
  2021年   6892篇
  2020年   6505篇
  2019年   5696篇
  2018年   5550篇
  2017年   5943篇
  2016年   6304篇
  2015年   5890篇
  2014年   11071篇
  2013年   13365篇
  2012年   9199篇
  2011年   9655篇
  2010年   7890篇
  2009年   7083篇
  2008年   6905篇
  2007年   7409篇
  2006年   6543篇
  2005年   5740篇
  2004年   4699篇
  2003年   4299篇
  2002年   3383篇
  2001年   3099篇
  2000年   2550篇
  1999年   2048篇
  1998年   1647篇
  1997年   1438篇
  1996年   1182篇
  1995年   1087篇
  1994年   869篇
  1993年   664篇
  1992年   592篇
  1991年   538篇
  1990年   475篇
  1989年   409篇
  1988年   378篇
  1987年   332篇
  1986年   258篇
  1985年   350篇
  1984年   303篇
  1983年   241篇
  1982年   235篇
  1981年   210篇
  1980年   192篇
  1979年   146篇
  1978年   101篇
  1977年   61篇
  1976年   68篇
  1975年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Introduction: Ischemic stroke is becoming a primary cause of disability and death worldwide. To date, therapeutic options remain limited focusing on mechanical thrombolysis or administration of thrombolytic agents. However, these therapies do not promote neuroprotection and neuro-restoration of the ischemic area of the brain.

Areas covered: This review highlights the option of minimal invasive, intra-arterial, administration of biological agents for stroke therapy. The authors provide an update of all available studies, discuss issues that influence outcomes and describe future perspectives which aim to improve clinical outcomes. New therapeutic options based on cellular and molecular interactions following an ischemic brain event, will be highlighted.

Expert opinion: Intra-arterial administration of biological agents during trans-catheter thrombolysis or thrombectomy could limit neuronal cell death and facilitate regeneration or neurogenesis following ischemic brain injury. Despite the initial progress, further meticulous studies are needed in order to establish the clinical use of stem cell-induced neuroprotection and neuroregeneration.  相似文献   

42.
43.
44.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
45.
46.
47.
李志道教授经过50余年临床实践研究,结合解剖学相关知识,发现委中、承山二穴在针刺深度与传统认识有所不同。其中,委中穴在刺入0. 5~0. 8寸,承山穴在刺入2. 0~3. 0寸时最易达到循经得气的效果,通过调整针尖方向还可较准确达到气至病所的效果,且针感与相应神经分布区域相吻合。该针感在某些疾病,尤其神经压迫相关症状的治疗中疗效明显,且优于传统教材所述针刺深度。  相似文献   
48.
当代社会,老年人口比例呈现不断上升的趋势,老龄化问题日益严峻。因此,如何有效地延缓衰老不仅成为了世界医学研究的热点,也成为了全球亟待解决的问题。中医药在延缓衰老方面经验丰富,而滋阴药在此类研究中效果显著。本文通过整理滋阴药抗衰老作用机制的若干文献,对滋阴复方六味地黄丸、二至丸、左归丸及其他滋阴中药延缓衰老的机制研究进展进行综述。  相似文献   
49.
        绝经是一个古老的概念,见诸于文献,最早可以追溯到春秋时期中医的重要文献之一《黄帝内经》。其中,《素问·上古天真论》有这样的描述:“女子二七而天葵至,任脉通,太冲脉盛,月事以时下,故有子……七七任脉虚,太冲脉衰少,天葵竭,地道不通,故形坏而无子也。”绝经是卵巢功能衰竭所造成的一种生命现象,从理论上讲,经过长期的进化的洗礼,人体所有的器官和组织,都是维持人体生命活动不可或缺的重要组成部分。时至今日,在不同的流行病学调查中,女性平均绝经年龄仍保持在50岁左右[1-2],可谓亘古未变,而变化的是人类寿命的延长,2018年北京女性预期寿命已经达84.63岁。 浏览更多请关注本刊微信公众号及当期杂志。  相似文献   
50.
ABSTRACT

HIV-positive men who have sex with men (HIV+MSM) in India need culturally-relevant interventions to promote safer sex. We tested a multi-level intervention among HIV+MSM that targeted individual, interpersonal, and community factors, based on the Social-Personal and Social Ecological Models. We conducted a 2?×?2 factorial RCT with 119 HIV+MSM randomised to receive either an individual-level intervention (ILI) using motivational interviewing to promote safer sex, a community-level intervention (CLI) to strengthen community norms toward safer sex and reduce stigma among MSM communities, a multi-level intervention combining the individual- and community-level interventions (ILI?+?CLI), or standard-of-care control. Participants completed pre- and post-intervention assessments of a composite sexual risk score and a process evaluation to assess fidelity and satisfaction. Out of the 119 HIV+MSM, 106 (89.0%) completed pre- and post-intervention assessments. Generalised Estimating Equation models showed that both CLI (Incidence Rate Ratio [IRR]?=?.67, 95% CI .47 to .96) and ILI?+?CLI (IRR?=?.66, 95% CI .48 to .91) groups had a statistically significant decrease in sexual risk compared to the standard-of-care. The interventions had high levels of fidelity and satisfaction. This pilot RCT demonstrated feasibility and potential effectiveness of a multi-level intervention that addresses individual, interpersonal and community-level contributors of sexual risk among HIV+MSM.  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