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   896篇
  免费   73篇
  国内免费   17篇
耳鼻咽喉   8篇
儿科学   7篇
妇产科学   6篇
基础医学   90篇
口腔科学   22篇
临床医学   78篇
内科学   68篇
皮肤病学   5篇
神经病学   33篇
特种医学   49篇
外科学   60篇
综合类   123篇
预防医学   287篇
眼科学   23篇
药学   81篇
中国医学   22篇
肿瘤学   24篇
  2023年   11篇
  2022年   40篇
  2021年   33篇
  2020年   44篇
  2019年   37篇
  2018年   30篇
  2017年   16篇
  2016年   36篇
  2015年   24篇
  2014年   76篇
  2013年   65篇
  2012年   63篇
  2011年   56篇
  2010年   52篇
  2009年   45篇
  2008年   44篇
  2007年   27篇
  2006年   35篇
  2005年   35篇
  2004年   34篇
  2003年   23篇
  2002年   18篇
  2001年   18篇
  2000年   15篇
  1999年   11篇
  1998年   6篇
  1997年   6篇
  1996年   11篇
  1995年   6篇
  1994年   5篇
  1993年   4篇
  1992年   5篇
  1991年   8篇
  1990年   5篇
  1989年   5篇
  1988年   2篇
  1987年   2篇
  1985年   3篇
  1984年   3篇
  1983年   2篇
  1981年   5篇
  1979年   3篇
  1978年   3篇
  1975年   1篇
  1973年   5篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有986条查询结果,搜索用时 31 毫秒
1.
目的对某跨区域医联体核心医院的运行效率进行评价,以不完全契约理论为分析视角探讨影响因素,为深化医联体建设提供借鉴和参考。方法收集2014年-2021年核心医院相关数据,采用DEA数据分析方法,计算运行效率变化情况。结果核心医院各项投入明显增加,医疗业务产出同步增长,医院运行效率经历了动态波动后持续向好。结论通过构建管理共同体,逐步优化契约,争取医保政策支持,合作共建初见成效。  相似文献   
2.
3.
In present constrained economic circumstances, many governments have introduced or increased user charges for health services. This has been advocated by the World Bank, justified by reference to the raising of revenue, efficiency and, controversially, even the promotion of equity. This paper examines the impact of user charges on utilisation in the Ashanti-Akim district of Ghana since the introduction of charges in 1985. In many ways, user charges have been a success: in recovering fees and maintaining urban utilisation. However some advantages have not materialised because the health infrastructure has not changed adequately. More importantly, equity and affordability have been problematical. For some of the population, services are no longer affordable.  相似文献   
4.
595 nm可调脉冲染料激光治疗皮肤血管异常性疾病疗效分析   总被引:1,自引:0,他引:1  
目的观察595nm可调脉冲染料激光治疗皮肤血管异常性疾病(血管畸形与血管瘤)的临床疗效。方法应用595nm可调脉冲染料激光治疗396例皮肤血管异常性疾病,观察临床疗效。结果毛细血管扩张和蜘蛛痣疗效最好,有效率为100%,其次是草莓状血管瘤,有效率为92.4%,鲜红斑痣为82.8%。面积越小,年龄越小,疗效越好(P<0.05);性别与疗效无明显差异。术中疼痛较轻,术后副作用少。结论595nm可调脉冲染料激光治疗皮肤血管异常性疾病安全性高,疗效确切。  相似文献   
5.
There are some general considerations which have implications for the delivery and finance of health care in all countries, not only Canada and the USA. Beginning with two propositions: that access to health care is a right of citizenship, which should not depend on individual income and wealth; and that the objective of health services is to maximise the impact on the nation's health of the resources available; the paper examines the ethical justification for pursuing efficiency in health care provision. The different meanings of efficiency are discussed in detail, and the use of quantitative indicators of health benefit, such as the QALY, placed in context. It is argued that the determination of health care resource allocations should take account of costs at both the macro planning level and the micro level of the individual doctor-patient relationship. Given the starting points the overall conclusion is that it is ethical to be efficient, since to be inefficient implies failure to achieve the ethical objective of maximising health benefits from available resources.  相似文献   
6.
A new radioactivity solution standard of 210Pb has been developed and will be disseminated by the National Institute of Standards and Technology (NIST) as standard reference material (SRM) 4337. This new 210Pb solution standard is contained in a 5 mL flame-sealed borosilicate glass ampoule, consists of (5.133±0.002) g of a nominal 1 mol L−1 nitric acid solution, has a density of (1.028±0.002) g mL−1 at 20 °C, has carrier ion concentrations of about 11 μg Pb2+ and 21 μg Bi3+ per gram of solution, and is certified to contain a massic activity (9.037±0.22) kBq g−1 as of the reference time 1200 EST, 15 June 2006. All of the uncertainties cited above correspond to standard uncertainties multiplied by a coverage factor k=2. The standardization for the 210Pb content of the solution was based on 4πβ liquid scintillation (LS) measurements using CIEMAT/NIST 3H-standard efficiency tracing (CNET). Confirmatory determinations were also performed by high-resolution HPGe γ-ray spectrometry, by 2π spectrometry with a Si surface barrier detector of separated 210Po, and by 4πβ(LS)–γ(NaI) anticoincidence counting.  相似文献   
7.
贵州省实施妇幼卫生项目效果分析   总被引:2,自引:0,他引:2  
报道5个实施妇幼卫生项目县(市)与6个非项目县(市)妇女卫生状况的调查比较。揭示实施项目工作5年来,贵州省妇幼卫生工作取得很大进展,孕产妇死亡率由实施前236.8/10万降至149.1/10万。其中项目县降至96.8/10万,非项目县降至181.8/10万。新法接生率、产前检查率与产后访视率均比项目实施前有明显提高。项目工作的实施促进了项目地区基层网络与妇幼队伍的建设,提高了基层人员妇幼卫生服务的主动性,出现了新婚女性婚姻生育观念的转变。还必须深入持久地推行孕产妇系统管理,尤其是高危孕产妇的分级管理,努力提高住院分娩率,才能大幅度降低孕产妇的死亡率  相似文献   
8.
李枫  刘德敏  侯伟光 《西部医学》2023,35(8):1167-1172
研究经皮内镜下可视化置钉在经皮内镜下后路腰椎融合术(End-PLIF)椎弓根螺钉置钉中的应用价值。方法 纳入2020年10月—2021年4月我院有腰椎融合手术指征的腰椎间盘源性腰痛、腰椎管狭窄症伴腰椎不稳、腰椎间盘突出症伴腰椎不稳、腰椎滑脱症(Meyerding分级I、II)患者共50例。50例患者随机分为甲、乙两组,每组25例。甲组的手术方式为经皮内镜下后路腰椎融合术+经皮脊柱内镜下可视化椎弓根螺钉置钉,乙组的手术方式为经皮内镜下后路腰椎融合术+传统X线透视下经皮椎弓根螺钉置钉。比较两组X线透视总次数、导丝置入时间、手术时间、术后住院时间;采用Gertzbein-Robbins标准评价置钉优良率;术前及术后24 h VAS评分和ODI指数、改良Macnab标准及术后并发症的发生率评价疗效。同时对经皮内镜下改进的置钉器械进行3D打印制造并验证其可行性、实用性。通过上述指标观察其医患X线辐射情况、微创性、置钉的优良率及手术效果。结果 全部患者均完成了手术和随访。甲组患者X线透视总次数、手术时间、导丝置入时间,均少于乙组(P<0.05),两组术后住院时间比较差异无统计学意义(P>0.05)。两组术前、术后24 h VAS、ODI比较差异无统计学意义(P>0.05),但两组术后24 hVAS、ODI均较术前改善(P<0.05)。末次随访时,两组患者改良Macnab标准的优良率比较差异无统计学意义(P>0.05)。甲组经皮内镜置钉优良率优于乙组(P<0.05)。两组患者术后并发症发生率比较差异无统计学意义(P>0.05)。结论 经皮内镜下置钉能减少医患X线辐射次数,降低医患辐射暴露风险,且置钉的优良率较高;同时,3D打印的经皮内镜下置钉器械具有可行性和实用性  相似文献   
9.
In this paper a complete energy balance for water locomotion is attempted with the aim of comparing different modes of transport in the aquatic environment (swimming underwater with SCUBA diving equipment, swimming at the surface: leg kicking and front crawl, kayaking and rowing). On the basis of the values of metabolic power (), of the power needed to overcome water resistance (d) and of propelling efficiency (P=d/tot, where tot is the total mechanical power) as reported in the literature for each of these forms of locomotion, the energy cost per unit distance (C=/v, where v is the velocity), the drag (performance) efficiency (d=d/) and the overall efficiency (o=tot/=d/P) were calculated. As previously found for human locomotion on land, for a given metabolic power (e.g. 0.5 kW=1.43 l·min–1 O2) the decrease in C (from 0.88 kJ·m–1 in SCUBA diving to 0.22 kJ·m–1 in rowing) is associated with an increase in the speed of locomotion (from 0.6 m·s–1 in SCUBA diving to 2.4 m·s–1 in rowing). At variance with locomotion on land, however, the decrease in C is associated with an increase, rather than a decrease, of the total mechanical work per unit distance (Wtot, kJ·m–1). This is made possible by the increase of the overall efficiency of locomotion (o=tot/=Wtot/C) from the slow speeds (and loads) of swimming to the high speeds (and loads) attainable with hulls and boats (from 0.10 in SCUBA diving to 0.29 in rowing).  相似文献   
10.
 The mechanical and energy characteristics of isolated fast-twitch muscle fibres (type 1) of Xenopus laevis in isometric- and isovelocity contractions were measured at 20°C. The fibres were stimulated at either 60 Hz or 20 Hz to produce contractions at different levels of activation. The high stimulation frequency gave fused contractions, while at the low stimulation frequency tension fluctuated. When maximum isometric force had been reached, the fibres were shortened by 10% of the fibre length at different velocities. At 60 Hz stimulation during shortening the rate of heat production increased above the isometric rate of heat production. At 20 Hz stimulation during shortening, however, the rate of heat production was not different from the isometric rate of heat production. Mechanical efficiency was the same at the high and low level of activation. The actomyosin efficiency (i.e. the mechanical efficiency corrected for ”activation heat”) was highest at the low level of activation. We conclude that in fast-twitch muscle fibres from X. laevis, actomyosin efficiency is highest for partially activated muscle. From a comparison of the present results with those obtained from a study of slow-twitch muscle fibres presented earlier, it is concluded that fast-twitch muscle fibres are less efficient than slow-twitch muscle fibres. Received after revision: 13 May 1997 / Accepted: 1 July 1997  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