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   2449篇
  免费   183篇
  国内免费   47篇
耳鼻咽喉   8篇
儿科学   53篇
妇产科学   15篇
基础医学   147篇
口腔科学   20篇
临床医学   73篇
内科学   253篇
皮肤病学   192篇
神经病学   32篇
特种医学   46篇
外科学   123篇
综合类   216篇
一般理论   1篇
预防医学   910篇
眼科学   5篇
药学   374篇
  3篇
中国医学   176篇
肿瘤学   32篇
  2023年   24篇
  2022年   41篇
  2021年   66篇
  2020年   74篇
  2019年   67篇
  2018年   67篇
  2017年   56篇
  2016年   88篇
  2015年   87篇
  2014年   131篇
  2013年   189篇
  2012年   97篇
  2011年   114篇
  2010年   106篇
  2009年   96篇
  2008年   97篇
  2007年   74篇
  2006年   79篇
  2005年   103篇
  2004年   65篇
  2003年   62篇
  2002年   49篇
  2001年   48篇
  2000年   36篇
  1999年   27篇
  1998年   37篇
  1997年   35篇
  1996年   15篇
  1995年   34篇
  1994年   29篇
  1993年   31篇
  1992年   30篇
  1991年   25篇
  1990年   20篇
  1989年   27篇
  1988年   19篇
  1987年   13篇
  1985年   41篇
  1984年   53篇
  1983年   42篇
  1982年   41篇
  1981年   33篇
  1980年   36篇
  1979年   36篇
  1978年   24篇
  1977年   24篇
  1976年   27篇
  1975年   26篇
  1974年   19篇
  1973年   6篇
排序方式: 共有2679条查询结果,搜索用时 15 毫秒
1.
Patient organisations contribute to many areas of pharmaceutical policy. In developing their organisational capacity, many turn to financial support from pharmaceutical companies, which may create conflicts of interests. However, the transparency of the industry’s self-regulatory approach to the disclosure of payments to patient organisations has evaded scrutiny. Using company reports disclosing payments to UK patient organisations in 2012–2016, we evaluate the transparency of reporting using indicators derived from industry’s European patient organisation Code. We found a large proportion of companies did not have any disclosure reports available despite many having made payments, confirmed by comparing with annual financial accounts of patient organisations registered as charities. Where disclosure reports were available, many payments were not adequately described, resulting in large portions of money being disclosed without clarity as to the payment type and purpose. We found companies were clearer regarding whether payments were financial or benefits-in-kind, but transparency was particularly inadequate as to whether it could be determined if payments were indirect or direct and restricted or unrestricted, and almost no companies mentioned the VAT status of payments. Our findings suggest that the industry’s self-regulatory approach to transparency has not been working efficiently. We suggest ways for standardising and increasing the precision of information by pharmaceutical companies and advocate for the introduction of a centralised, and easily accessible national-level payment database.  相似文献   
2.
从产业组织学角度看中国医疗广告   总被引:1,自引:0,他引:1  
吴国术 《中国药事》2005,19(9):532-534
随着医疗卫生体制改革的全面推行,医疗行业竞争日趋激烈,众多医院采取不同的策略组合以提高其核心竞争力,而广告正是其主要的营销策略之一.本文在对医疗广告特性、类别、作用进行分析的基础上,从产业组织学角度阐述了医疗广告与医疗市场结构、市场效益的关系,提出了中国医疗广告的发展趋势.  相似文献   
3.
Pharmacokinetic parameters of two antifolates, trimethoprim and aditoprim, were studied in buffalo calves. The elimination half-life of aditoprim (6.14 h) was nearly twice as long as that of trimethoprim (3.08 h) and compares well with values observed in heifers. This longer half-life of aditoprim is a result of its much larger distribution volume (four to five times larger) because the clearance of aditoprim was about twice as high as that of trimethoprim. The longer half-life of aditoprim is expected to give a longer duration of in vivo bacteriostatic activity than that of trimethoprim.  相似文献   
4.
化工行业职业性机械伤害危险因素的病例-交叉方法研究   总被引:6,自引:0,他引:6  
目的 研究化工行业机械伤害的有关诱发因素,估计其作用强度。方法 采用病例-交叉设计的方法。以操作和检修时受伤的化工工人为研究对象,每个对象在受伤后2d内完成调查,收集他们受伤前10min、上一工作日同一段时间和受伤前1周内有关诱发因素暴露的信息,用配对时间段方法和一般频数法进行分析,评估各种诱发因素的危险度。结果 一般频数法分析的结构表明,操作方法异常、设备工具缺陷、工作紧迫、注意力不集中、不使用防护用品、精神状况较差、与同事配合不协调、工作环境发生变化等瞬时危害因素的RR值及95%可信限的下限均大于1。配对时间段方法分析的结果与其相拟,但95%可信限较宽。结论 化工行业职业性机械伤害的发生存在着诸多诱发因素。病例-交叉研究中的一般频数法与配对时间段方法相比,前者所得结果较为可靠,研究的相对效率较高。建议进一步使用多个时间段方法进行研究,以减小混杂因素的影响。  相似文献   
5.
目的建立简单快速提取并测定N-亚硝基二正丙胺(NDPA)的方法。方法采用Trap3捕集管,利用标准吹扫捕集程序(吹扫气体流速40ml/min,吹扫时间11min,解吸温度225℃,解吸时间4min,烘烤温度230℃,烘烤时间10min),有效富集了化工废水中μg/L级的NDPA,建立了吹扫捕集(P&T)气相色谱质谱联用(GC-MS)化学源(CI)选择离子模式(uSIS)快速、准确分析废水中NDPA的分析方法。结果方法的相对标准偏差为7.5%;废水的加标回收率在62.60%~96.31%;在5~30μg/L范围内线性良好,线性回归系数为0.978;方法的最低检出限为3μg/L。结论采用P&T-GC-MS/CI/uSIS法可用于化工废水中半挥发性有机物NDPA的测定。  相似文献   
6.
7.
医疗商业贿赂已引起全社会的高度关注,成为2006年六大重点领域里治理的商业贿赂之一。作者通过分析医疗商业贿赂的危害和原因,提出:①加强思想教育;②坚持依法行政;③完善相关制度;④深化体制改革;⑤完善监督制度等预防对策。  相似文献   
8.
4 aircraft construction workers developed allergic contact dermatitis of the hands and forearms. The allergen was hexavalent chromate in the accelerating solution of an epoxy-based sealant (PR1422). Although chromate dermatitis from an epoxy resin has been described, epoxy system accelerators are a hitherto unrecognized source of occupational chromate dermatitis.  相似文献   
9.
Objective  The objective of this study was to describe the perceived health status of the meat industry employees—i.e., working in the slaughtering, cutting, and boning of large animals and poultry—and its relation to their organisational and psychosocial constraints at work. Methods  This postal survey included all 3,000 employees of the meat industry (beef, pork and poultry) in four districts in Brittany, France, whose companies were affiliated with the agricultural branch of the national health insurance fund. The questionnaire asked for social and demographic data and information describing their job and the organisation of their work. The psychosocial factors at work were described according to Karasek’s questionnaire (demand, latitude and social support at work). Perceived health was measured with the Nottingham Health Profile perceived health indicator. Results  This study shows the high prevalence of poor health reported by the workers in this industry. This poor perceived health was worse in women and increased regularly with age. Among the psychosocial factors studied, high quantitative and qualitative demand at work, inadequate resources for good work and to a lesser extent, inadequate prospects for promotion appear especially associated with poor perceived health. Other factors often associated with poor perceived health included young age at the first job and work hours that disrupt sleep rhythms (especially for women). Conclusion  Our results show that this population of workers is especially vulnerable from the point of view of perceived physical and psychological health and is exposed to strong physical, organisational and psychosocial constraints at work. They also demonstrate that poor perceived health is associated with some psychosocial (such as high psychological demand and insufficient resources) and organisational factors at work. These results, in conjunction with those from other disciplines involved in studying this industry, may help the companies to develop preventive activities.  相似文献   
10.
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