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   120937篇
  免费   11556篇
  国内免费   3715篇
耳鼻咽喉   1057篇
儿科学   1489篇
妇产科学   1487篇
基础医学   13855篇
口腔科学   4297篇
临床医学   13083篇
内科学   12718篇
皮肤病学   1496篇
神经病学   7533篇
特种医学   4075篇
外国民族医学   17篇
外科学   10725篇
综合类   18084篇
现状与发展   9篇
一般理论   6篇
预防医学   18296篇
眼科学   1474篇
药学   15123篇
  158篇
中国医学   6213篇
肿瘤学   5013篇
  2024年   492篇
  2023年   2279篇
  2022年   4532篇
  2021年   5860篇
  2020年   5580篇
  2019年   4923篇
  2018年   4423篇
  2017年   4763篇
  2016年   4694篇
  2015年   4660篇
  2014年   8078篇
  2013年   8982篇
  2012年   7754篇
  2011年   8155篇
  2010年   6212篇
  2009年   5876篇
  2008年   5665篇
  2007年   5614篇
  2006年   4814篇
  2005年   4214篇
  2004年   3563篇
  2003年   3262篇
  2002年   2545篇
  2001年   2389篇
  2000年   1900篇
  1999年   1669篇
  1998年   1582篇
  1997年   1405篇
  1996年   1216篇
  1995年   1106篇
  1994年   1040篇
  1993年   811篇
  1992年   750篇
  1991年   674篇
  1990年   568篇
  1989年   554篇
  1988年   501篇
  1987年   442篇
  1986年   354篇
  1985年   477篇
  1984年   361篇
  1983年   226篇
  1982年   248篇
  1981年   201篇
  1980年   186篇
  1979年   144篇
  1978年   116篇
  1977年   77篇
  1976年   97篇
  1974年   53篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
目的 探讨产后出血的原因与影响因素。方法 回顾分析收治的产后出血 15 9例 ,数据处理采用χ2 检验。结果 产后出血发生率 3.5 % ,产后 2小时内出血者 88.6 7% ,出血原因宫缩乏力为 6 6 .6 7% ,影响因素有手术产、流产史、分娩史、妊娠合并症及产程延长等 ,统计学处理P <0 .0 1。结论 重视产后出血的影响因素 ,正确评估出血量及产妇产后 2小时留置产房观察是产后出血早期诊断的关键 ,其预防重点在于早期发现并针对不同原因及时正确处理  相似文献   
82.
The quality of medical education during internship is a cause for concern. This paper describes a structured educational programme for interns that was based around learning modules, clinical attachments and bedside teaching. The programme was incorporated into the term rotation of interns within an Area Health Service, and evaluated. Learning modules were timetabled by a Programme Coordinator and interns were reminded to attend. Clinical attachments were organized by the interns from a list of willing supervisors. Attendance at timetabled learning modules averaged 67%, which was greater than the 27% attendance at clinical attachments. Both sessions received high ratings for quality and clinical relevance. This structured education programme was based upon adult learning methods and was both feasible and well received by interns. Intern training programmes need to be programmed into the working week to ensure attendance, and modified following evaluation by interns. Such programmes should be considered by all hospitals to which interns are allocated.  相似文献   
83.
Three representations of the conditional independences due toMendelian segregation of genes in a pedigree are proposed. Thecomputational costs of performing calculations using the techniqueof peeling with each of these representations is compared byconsidering the weights of triangulations of the graph producedby each representation.  相似文献   
84.
格拉斯哥评分的纯数学意义及临床评估价值   总被引:2,自引:0,他引:2  
总结1022例颅脑外伤进行格拉斯哥评分的实践实验,从纯数学意义上评价了评分在临床上的应用价值。指出格拉斯哥评分各参数之间只有15种组合最常见且有临床价值。数学分析表明运动反应最有决定性意义;同时指出格拉斯可评分对患者预后判断有重要评估价值。评分的不足之处在于不能反映瞳孔改变和脑干症状。  相似文献   
85.
This is a retrospective study analysing 5264 patients treated in the burn centre at Gülhane Military Medical Academy from 1 January 1986 to 31 December 1995. Our burn centre is not only the firs, but one of the best established and supported in Turkey. Our present study has the largest patient group of other previously published studies from Turkey. Of the total patients studied, 4464 patients had minor burns and were treated on an outpatient basis and 800 patients had moderate to major burns. Although our centre is in a military area in Ankara, only 1047 (20 per cent) patients were military personnel and the military-related burn causes comprised only 6 per cent of the total. The remaining 4217 (80 per cent of the total patients) were civilians. Flame injuries were also more frequent in military patients than civilians. Minor burns were most common in the age group 0–10 years old (40 per cent) and moderate to major burns in the age group 21–30 years (54 per cent). Scalds were the main cause of paediatric burns. Male patients were dominant. The overall mortality among inpatients was 18.2 per cent and mean total body surface area (TBSA) was 57.6 per cent in patients who died. 134 patients demonstrated inhalation injury and 82 per cent of these patients died. The epidemiological pattern of our patients is similar to that in other studies from developed countries, although some ethnic causative factors could be found. Our study indicates that emergency measures should be taken to prevent flame injuries at military barracks and industrial workplaces and scalding accidents to children at home and throughout the country.  相似文献   
86.
We assessed the feasibility and psychometric properties of two commonly used health status questionnaires in Parkinson's disease (PD): the generic Nottingham Health Profile (NHP) and the disease-specific 39-item Parkinson's disease Questionnaire (PDQ-39), from a cross-sectional postal survey of PD patients (N = 81), using traditional and Rasch measurement methodologies. Overall response rate was 88%. Both questionnaires were found feasible, although the NHP performed less well. The PDQ-39 had fewer floor effects and was better able to separate respondents into distinct groups than the NHP, whereas the latter exhibited less ambiguous dimensionality and better targeting of respondents with non-extreme scores. Reliability and validity indices were similar, and potential differential item functioning by age and gender groups was found for both questionnaires. PDQ-39 response alternatives indicated ambiguity. With few exceptions, questionnaire scales were unable to meet recommended standards fully. While preliminary, this study illustrates the need for thorough evaluation of outcome measures and has implications beyond the questionnaires used here. Although promising, both questionnaires warrant further developmental work and stronger support of measurement validity before they could be considered fully suitable for valid use in PD, in particular in earlier stages of the disease.  相似文献   
87.
We have developed a computerized neuromuscular monitoring system (NMMS) using commercially available subsystems, i.e., computer equipment, clinical nerve stimulator, force transducer, and strip-chart recorder. This NMMS was developed for acquisition and analysis of data for research and teaching purposes. Computer analysis of the muscle response to stimulation allows graphic and numeric presentation of the twitch response and calculated ratios. Since the system can store and recall data, research data can be accessed for analysis and graphic presentation. An IBM PC/AT computer is used as the central controller and data processor. The computer controls timing of the nerve stimulator output, initiates data acquisition, and adjusts the paper speed of the strip chart recorder. The data processing functions include establishing control response values (when no neuromuscular blockade is present), displaying force versus time and calculated data graphically and numerically, and storing these data for further analysis. The general purpose nature of the computer and strip chart recording equipment allow modification of the system primarily by changes in software. For example, new patterns of nerve stimulation, such as the posttetanic count, can be programmed into the computer system along with appropriate data display and analysis routines. The NMMS has functioned well in the operating room environment. We have had no episodes of electrocautery interference with the computer functions. The automated features have enhanced the utility of the NMMS. The prime advantages of this system are (1) the ability to customize its features by altering its controlling programs, (2) the ready availability of the hardware and software, (3) the general purpose nature of the system, so that it is not limited to this one application, and (4) the adaptable nature of the system.  相似文献   
88.
目的:获得SENV-D亚型ORF1-C端蛋白基因序列,并进行表达,为进一步研究及诊断、治疗应用奠定基础.方法:用PCR法从SENV阳性血清中获得SENV-DORF1C端基因,测序验证后,构建了pQE30-SENV-D重组表达质粒,并经过转化E.coli M15,IPTG诱导表达,Western blot分析表达结果.结果:获得了正确序列的SENV-D亚型ORF1-C端蛋白基因序列,表达出Mr约为38×103的蛋白.表达蛋白能与患者血清中相应的抗体结合,发生抗原抗体反应.结论:成功获得并表达了SENV-D-ORF1-C端蛋白,并经Western blot印迹法证实能与阳性血清中的抗体发生抗原抗体反应,有可能用于检测SENV-D抗体.为今后进一步研究有助于疫情监测及早期发现感染者的抗体奠定了坚实的基础.  相似文献   
89.
2003年12月30日一辆装载7.28t苯胺的槽车从宁波开往温州的路上在甬台温高速公路温岭市境内翻车,造成5.3t左右的苯胺泄漏在高速公路旁的环境中,除少量的液体被清除外,绝大部分渗入地下,造成了水井污染.从12月31日开始我们对周围的水井开展了监测,现将监测结果分析如下:  相似文献   
90.
The United States and the Netherlands are the focus for this comparative analysis of the evolutionary interaction between health planning and the political system, seen in the context of change in social and economic ideologies. While health planning in the USA started in 1946, it was the comprehensive health planning program in 1966 that created the form to be followed by Health Systems Agency effort in 1974: local, voluntary planning, coordinated by state agencies, supported by federal funding. Health planning in the Netherlands has moved through four distinct periods: a hospital construction period, starting during the post-war recovery; a hospital regionalization period, from 1971 through the late 1970s; a transition period from the late 1970s to 1982, during which several planning approaches were considered; and, the current comprehensive health and social services planning period. Today, federal support for health planning in the US has been eliminated as part of the current de-regulatory, competitive health care strategy. Health planning in the US is now an institutional activity, with less focus on community needs. Advocated changes in the Dutch planning approach incorporate ideas similar to past approaches in the US; but, a failed approach in one nation may work in another, if the underlying cultural and organizational characteristics are sufficiently different.  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