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   24297篇
  免费   2354篇
  国内免费   410篇
耳鼻咽喉   138篇
儿科学   330篇
妇产科学   420篇
基础医学   1965篇
口腔科学   366篇
临床医学   4950篇
内科学   2562篇
皮肤病学   342篇
神经病学   646篇
特种医学   678篇
外国民族医学   1篇
外科学   2573篇
综合类   1933篇
一般理论   4篇
预防医学   4320篇
眼科学   180篇
药学   4091篇
  39篇
中国医学   673篇
肿瘤学   850篇
  2024年   46篇
  2023年   719篇
  2022年   1000篇
  2021年   1566篇
  2020年   1586篇
  2019年   1596篇
  2018年   1642篇
  2017年   1378篇
  2016年   1157篇
  2015年   1117篇
  2014年   2054篇
  2013年   2458篇
  2012年   1517篇
  2011年   1438篇
  2010年   1164篇
  2009年   1091篇
  2008年   962篇
  2007年   911篇
  2006年   758篇
  2005年   566篇
  2004年   435篇
  2003年   323篇
  2002年   275篇
  2001年   233篇
  2000年   157篇
  1999年   132篇
  1998年   110篇
  1997年   79篇
  1996年   89篇
  1995年   67篇
  1994年   50篇
  1993年   39篇
  1992年   56篇
  1991年   39篇
  1990年   32篇
  1989年   22篇
  1988年   27篇
  1987年   25篇
  1986年   20篇
  1985年   33篇
  1984年   20篇
  1983年   13篇
  1982年   13篇
  1981年   10篇
  1980年   9篇
  1979年   8篇
  1978年   3篇
  1977年   7篇
  1975年   3篇
  1973年   3篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
吉林放射事故病人血浆造血活性观察   总被引:4,自引:0,他引:4       下载免费PDF全文
目的观察病人血浆造血活性,了解其与照后造血功能变化的可能关系。方法以MTT法测病人血浆对NFS-60、TF-1和BET-2细胞因子依赖细胞株在有或无相应细胞因子存在时的吸光度(492nm)。结果患者血清有类似GM-CSF、IL-3和EPO的刺激活性。血浆加入含rhG-CSF和EPO的培养体系中可使NFS-60和BET-2细胞增殖受抑。上述变化与病人外周血白细胞、红细胞及血红蛋白的变化有相关之处。结论吉林辐射事故病人血浆中有粒系和红系造血抑制活性。  相似文献   
102.
医用氧舱检验与安全   总被引:1,自引:1,他引:0  
本文介绍了医用氧舱的检验,医用氧舱的检验包括舱体、供排气、氧系统、电气系统等“硬件”设备的检验和设计、安装与使用管理的“软件”方面的检验。同时,针对检验过程中发现的影响医用氧舱安全使用的常见问题,本文进行了详细的讨论。  相似文献   
103.
防晒制剂皮肤安全性的实验研究   总被引:2,自引:0,他引:2  
目的 :探讨同一系列不同SPF(sunprotectionfactor)防晒制剂对皮肤的安全性 ,筛选安全有效的防晒制剂配方。方法 :选用白化豚鼠背部去毛 ,分别涂抹SPF值为 15、2 8、30 +三种防晒制剂 ,以UV光源照射 ,波长为 32 0~4 0 0nm ,强度为 ( 16 8± 2 )mW/cm2 。结果 :三种不同SPF防晒制品对实验动物皮肤各时相点反应积分为 ,SPF15组为0 ;SPF2 8组为 1;SPF30 +组为 3。结论 :三种不同SPF值产品对皮肤的光毒性有一定差异 ,提示SPF值在 2 8以内的防晒制剂皮肤安全性较好 ,SPF30 +的防晒制剂对皮肤有一定光毒刺激反应。  相似文献   
104.
第1产程潜伏期指导对分娩的影响   总被引:1,自引:0,他引:1  
目的 :观察规范指导对处于分娩第 1产程潜伏期孕妇的影响。方法 :为处于分娩第 1产程潜伏期的 15 0例产妇讲解分娩知识 ,训练助产动作 ,树立自然分娩信心 ,并动态观察产妇的分娩情况。以条件相同 ,未在潜伏期做指导的产妇 15 0例为对照组。结果 :观察组总产程、第 1产程活跃期及第 2产程明显短于对照组 (P <0 0 1) ,新生儿窒息率、剖宫产率明显低于对照组(P <0 0 1)。第 1产程潜伏期、阴道助产率及产后出血发生率两组差异无显著性。结论 :在第 1产程潜伏期对产妇进行规范指导可以缩短产程 ,促进自然分娩 ,降低新生儿窒息发生率。  相似文献   
105.
对部队汽车驾驶员203名的心身健康和行车安全的相关因素研究表明:驾驶员可发生心身障碍,尤其眼和耳、呼吸系统,骨胳肌肉系统及抑郁等为著。其影响因素,主要有负性精神紧张总值(-Lcu)、个性的精神质、神经质、掩饰性、内向倾向、开车公里数、开车年限及精神疾病家族史。某些心身问题、神经质、掩饰性较高、年龄偏大、开车公里数多及开车年限长等与事故差错的发生有关。  相似文献   
106.
Challenging the world: patient safety and health care-associated infection.   总被引:2,自引:0,他引:2  
Improving the safety of patient care is an issue which affects health systems in both developed and developing countries. To co-ordinate and accelerate improvements in patient safety, the World Health Organization (WHO) has supported the creation of the World Alliance for Patient Safety which was launched in October 2004. The six action areas of the Alliance are Patients for Patient Safety, Taxonomy, Research, Solutions for Patient Safety, Reporting and Learning, and a biennial Global Patient Safety Challenge. The first Challenge covering 2005-2006 was launched in October 2005 under the banner 'Clean Care is Safer Care'. The Challenge addresses health care-associated infection, a major, patient safety problem affecting hundreds of millions of people worldwide.  相似文献   
107.
Psoriasis is a chronic, incurable disease that frequently requires long-term treatment. Although many patients benefit from effective traditional systemic therapies, namely methotrexate, cyclosporin, retinoids and fumaric acid esters, and some patients achieve long-term disease control, unrestricted long-term administration is not recommended due to the potential for cumulative toxicity. In order to diminish the risk of toxicity, physicians have adopted various treatment approaches (e.g. rotational, sequential, intermittent, and combination). However, these approaches may not provide continuous disease control or a stable treatment regimen. The recent advent of targeted biological therapeutics such as etanercept, infliximab, adalimumab, alefacept and efalizumab may offer physicians and their patients treatment options with improved safety profiles that may permit continuous disease control.  相似文献   
108.
Bayesian decision theoretic approaches (BDTAs) have been widely studied in the literature as tools for designing and conducting phase II clinical trials. However, full Bayesian approaches that consider multiple endpoints are lacking. Since the monitoring of toxicity is a major goal of phase II trials, we propose an adaptive group sequential design using a BDTA, which characterizes efficacy and toxicity as correlated bivariate binary endpoints. We allow trade‐off between the two endpoints. Interim evaluations are conducted group sequentially, but the number of interim looks and the size of each group are chosen adaptively based on current observations. We utilize a loss function consisting of two components: the loss associated with accruing, treating, and monitoring patients, and the loss associated with making incorrect decisions. The performance of our Bayesian modeling, and the operating characteristics of decision rules under a wide range of loss function parameters are evaluated using seven scenarios in a simulation study. Our method is illustrated in the context of a single‐arm phase II trial of bevacizumab, gemcitabine, and oxaliplatin in patients with metastatic pancreatic adenocarcinoma. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
109.
BACKGROUND: We tested whether transcranial magnetic stimulation (TMS) over the left dorsolateral prefrontal cortex (DLPFC) is effective and safe in the acute treatment of major depression. METHODS: In a double-blind, multisite study, 301 medication-free patients with major depression who had not benefited from prior treatment were randomized to active (n = 155) or sham TMS (n = 146) conditions. Sessions were conducted five times per week with TMS at 10 pulses/sec, 120% of motor threshold, 3000 pulses/session, for 4-6 weeks. Primary outcome was the symptom score change as assessed at week 4 with the Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes included changes on the 17- and 24-item Hamilton Depression Rating Scale (HAMD) and response and remission rates with the MADRS and HAMD. RESULTS: Active TMS was significantly superior to sham TMS on the MADRS at week 4 (with a post hoc correction for inequality in symptom severity between groups at baseline), as well as on the HAMD17 and HAMD24 scales at weeks 4 and 6. Response rates were significantly higher with active TMS on all three scales at weeks 4 and 6. Remission rates were approximately twofold higher with active TMS at week 6 and significant on the MADRS and HAMD24 scales (but not the HAMD17 scale). Active TMS was well tolerated with a low dropout rate for adverse events (4.5%) that were generally mild and limited to transient scalp discomfort or pain. CONCLUSIONS: Transcranial magnetic stimulation was effective in treating major depression with minimal side effects reported. It offers clinicians a novel alternative for the treatment of this disorder.  相似文献   
110.
Introduction  Medication errors are a preventable cause of patient injury. In May 2003, as a result of a joint initiative by the Royal College of Anaesthetists, the Association of Anaesthetists of Great Britain and Ireland, the Intercollegiate Faculty of Accident and Emergency Medicine and the Intensive Care Society, a new colour code chart for syringe labelling was introduced. The introduction of the new system has not been uniform in the Irish Republic with no national guidelines or time scale in place. Methods  A questionnaire was administered to doctors working in Anaesthesia in two Dublin teaching hospitals. Results  As much as 23% had administered an incorrect medication and 53% admitted to a near miss as a result of the introduction of the new label. Discussion  Future action should focus on practical, common sense interventions including techniques such as those that reduce reliance on memory, standardization, the use of protocols and checklists, and the elimination of look-alike products.  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