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   72572篇
  免费   6977篇
  国内免费   2471篇
耳鼻咽喉   158篇
儿科学   793篇
妇产科学   2030篇
基础医学   3517篇
口腔科学   579篇
临床医学   6680篇
内科学   7648篇
皮肤病学   1141篇
神经病学   2262篇
特种医学   726篇
外国民族医学   7篇
外科学   2602篇
综合类   9029篇
现状与发展   9篇
一般理论   4篇
预防医学   4973篇
眼科学   720篇
药学   32041篇
  47篇
中国医学   3111篇
肿瘤学   3943篇
  2024年   177篇
  2023年   1189篇
  2022年   1667篇
  2021年   2625篇
  2020年   2655篇
  2019年   2662篇
  2018年   2754篇
  2017年   2999篇
  2016年   2852篇
  2015年   2905篇
  2014年   4828篇
  2013年   8344篇
  2012年   4688篇
  2011年   4932篇
  2010年   3850篇
  2009年   3633篇
  2008年   3380篇
  2007年   3343篇
  2006年   3000篇
  2005年   2692篇
  2004年   2311篇
  2003年   2023篇
  2002年   1555篇
  2001年   1447篇
  2000年   1163篇
  1999年   977篇
  1998年   866篇
  1997年   801篇
  1996年   653篇
  1995年   615篇
  1994年   525篇
  1993年   459篇
  1992年   513篇
  1991年   416篇
  1990年   345篇
  1989年   279篇
  1988年   265篇
  1987年   252篇
  1986年   211篇
  1985年   222篇
  1984年   175篇
  1983年   143篇
  1982年   118篇
  1981年   92篇
  1980年   64篇
  1979年   64篇
  1978年   72篇
  1977年   49篇
  1976年   48篇
  1975年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The Theory of Rational Addictions, by Gary Becker & Kevin Murphy (1988), was a rational choice model that became a standard tool for economists modeling addictive behavior. The approach differs from other theories of addiction by modeling addictive behavior as the gradual implementation of a rational, forward‐looking plan, where consumption at any point in time is partly motivated by the immediate payoff of consumption and partly by the effects this consumption has on the individual in the future. This makes addictive behavior a subset of rational behavior, requiring no more specific government policies or attention than any other consumption choice. Later work by economists extended the theory in different ways, allowing it to match an increasing number of consumption patterns, and searched for ways to test the forward‐looking assumption in different types of market data. While the work was successful as a contribution to rational choice theory, with possible statistical applications, there are several reasons to dismiss its usefulness as an explanation of real‐world addictive behavior and its ability to assess the welfare effects of addictions.  相似文献   
12.
13.
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   

14.
15.
COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19.  相似文献   
16.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  相似文献   
17.
18.
19.
Bacterial infection of subcutaneous “pockets” housing cardiovascular implantable electronic devices is a significant clinical complication. In this study, pacemakers encapsulated in a blood plasma-based material (PBM) composited with antibiotics were investigated for use as prophylactics against such infections. PBMs, which are made from pooled allogeneic plasma and platelets, are off-the-shelf biomaterials that can be manufactured in the form of complex 3D shapes, extrudable putties, or injectable pastes. In vitro studies with PBM pastes formulated with rifampicin and minocycline demonstrated antibiotic release over 6 days, activity against Escherichia coli, and reduced cytotoxic effects of the antibiotics on fibroblasts. The materials were also evaluated in vivo in a rabbit model in which pacemaker pockets were inoculated with methicillin-resistant Staphylococcus aureus (S. aureus) strain and examined 1 week later. The pockets containing the pacemaker plus S. aureus were grossly purulent and culture positive, whereas pockets into which PBM with antibiotics were injected around the pacemaker were free of purulence and culture negative (p < 0.001). None of the pockets into which PBM without antibiotics were placed demonstrated purulence, but 60% were culture positive. These results demonstrate the potential of PBMs to deliver antibiotics to diminish the incidence of pocket infections for pacemakers and other implantable devices.  相似文献   
20.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  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