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   8864篇
  免费   657篇
  国内免费   341篇
耳鼻咽喉   144篇
儿科学   49篇
妇产科学   37篇
基础医学   861篇
口腔科学   71篇
临床医学   822篇
内科学   1118篇
皮肤病学   71篇
神经病学   1223篇
特种医学   82篇
外科学   275篇
综合类   1109篇
一般理论   2篇
预防医学   522篇
眼科学   51篇
药学   1901篇
  4篇
中国医学   1369篇
肿瘤学   151篇
  2024年   49篇
  2023年   146篇
  2022年   280篇
  2021年   354篇
  2020年   292篇
  2019年   218篇
  2018年   249篇
  2017年   184篇
  2016年   200篇
  2015年   226篇
  2014年   357篇
  2013年   562篇
  2012年   320篇
  2011年   399篇
  2010年   344篇
  2009年   353篇
  2008年   357篇
  2007年   394篇
  2006年   344篇
  2005年   309篇
  2004年   257篇
  2003年   266篇
  2002年   245篇
  2001年   233篇
  2000年   227篇
  1999年   203篇
  1998年   172篇
  1997年   177篇
  1996年   193篇
  1995年   156篇
  1994年   171篇
  1993年   126篇
  1992年   110篇
  1991年   114篇
  1990年   127篇
  1989年   94篇
  1988年   87篇
  1987年   92篇
  1986年   75篇
  1985年   106篇
  1984年   100篇
  1983年   74篇
  1982年   81篇
  1981年   84篇
  1980年   63篇
  1979年   51篇
  1978年   39篇
  1977年   43篇
  1976年   46篇
  1974年   35篇
排序方式: 共有9862条查询结果,搜索用时 671 毫秒
21.
目的 验证降糖灵 1号的降血糖作用。方法 以大、小白鼠为实验动物 ,分别与空白对照、高血糖对照及降糖甲片组和消渴丸组进行对照。研究降糖灵 1号对肾上腺素性和四氧嘧啶性高血糖的药理作用。结果 降糖灵 1号组除与消渴丸组对糖尿病差异无显著性意义 (P >0 0 5 )外 ,与其他各组差异均有显著性意义 (P <0 0 5 ,P <0 0 1)。结论 降糖灵 1号具有明显的降血糖作用  相似文献   
22.
Evaluation of students undertaking fieldwork education placements is a critical process in the health professions. As training programs and practice evolve, systems for assessing students need to be reviewed and updated constantly. In 1995, staff of the occupational therapy training program at the University of Queensland, Australia decided to develop a new tool for assessing student fieldwork performance. Using an action research methodology, a team developed the Student Placement Evaluation Form, a flexible and comprehensive criterion-referenced evaluation tool. The present paper examines action research as an appropriate methodology for considering real-life organisational problems in a systematic and participatory manner. The action research cycles undertaken, including preliminary information gathering, tool development, trial stages and current use of the tool, are detailed in the report. Current and future development of the tool is also described.  相似文献   
23.
Principles and strategies of effective community participation   总被引:7,自引:5,他引:2  
A framework is offered for understanding the conceptual basisand the strategic implications of community participation, inachieving Health for All goals. Special focus is given to themeaning, settings and levels of participation in official decision-makingstructures and at the community level. Questions such ‘howis participation facilitated?’, ‘who participates?’and ‘what are the benefits and obstacles to participation?’are geared primarily towards the needs of individuals who functionat the city level and expect practical strategic advice andguidance. The structure of the 1989 WHO Healthy Cities Symposiumwhich was devoted to community action was based on the frameworkand conceptual approach of this paper.  相似文献   
24.
法半夏罗汉果川贝枇把膏与强力批他露均有镇咳祛痰作用,罗汉果川贝枇把膏尚能平喘抗炎。  相似文献   
25.
. We have estimated sarcoplasmic reticulum calcium content using rapid application of caffeine on voltage clamped, isolated guinea-pig ventricular myocytes. Caffeine induces the release of calcium from the sarcoplasmic reticulum and this calcium is extruded from the cells by the sarcolemmal Na/Ca exchange. Integrating the inward Na/Ca exchange current thus allows estimations of sarcoplasmic reticulum calcium content. Ventricular myocytes were stimulated to reach new steady-states by action potential voltage clamps of varying duration. Once contractile steady-state had been reached caffeine was rapidly applied in place of the next action potential and sarcoplasmic reticulum calcium content measured. Prolonging the action potential duration increased sarcoplasmic reticulum calcium content and vice-versa. This calcium loading may underlie the positive inotropic effect of increased action potential duration. Received: 11 July 1996 / Received after revision: 15 October 1996 / Accepted: 26 November 1996  相似文献   
26.
薄荷醇对戊巴比妥中枢抑制作用的影响   总被引:1,自引:0,他引:1  
研究薄荷醇经胃肠道给药对成巴比妥中枢抑制作用的影响,结果发现,薄荷醇对戊巴比妥的中枢抑制作用具有一定的量效关系,含4.5%的薄荷醇溶液可明显使小鼠的入睡时间缩恒,并使急性死亡率增加,而含1.5%和0.5%的薄荷醇溶液对成巴比妥的中枢抑制作用无明显影响。  相似文献   
27.
Purpose. In the National Heart, Lung, and Blood Institute Guidelines for the Diagnosis and Management of Asthma, the expert panel recommends that a written asthma action plan be provided for all patients with asthma. Studies evaluating the usefulness of the asthma action plan in children are limited. We aim to determine exacerbation frequency and usefulness of the asthma action plan in managing exacerbations that occur in a pediatric primary care setting. Methods. Caretakers of asthmatic children attending the general pediatric clinic in an inner-city hospital completed a one-page questionnaire covering topics such as asthma severity, frequency of exacerbations, and possession/usefulness of an asthma action plan. Although controversy exists over the definition of yellow and red zone exacerbations, we defined the yellow zone as symptoms that require albuterol more than three times a day or more than two nights in succession. The red zone was defined as symptoms requiring systemic corticosteroids and/or an urgent physician visit. Results. Seventy of 75 subjects completed the survey. Almost 80% of respondents carried the diagnosis of persistent asthma, whereas the remainder had intermittent asthma. Exacerbation frequency over a 3-month period was determined. Approximately 80% of children experienced at least one yellow zone episode: 42% had one or two yellow zone episodes, and 39.6% had between three and five episodes. Sixty-three percent of patients did not experience a single red zone exacerbation. Almost 75% (44 of 59) of subjects possessed an asthma action plan. Ninety percent (37 of 41) of respondents with action plans found the plan to be useful in managing exacerbations. Conclusion. Approximately four of every five asthmatic children seen in this primary care setting experienced a yellow zone exacerbation at least once during a 3-month period. One third experienced at least one red zone episode. Nine of every 10 caretakers with an action plan reported the asthma action plan to be of value in managing exacerbations.  相似文献   
28.
本文采用小鼠精子试验和小鼠睾丸DNA合成抑制试验,检测了JX-1对雄性生殖细胞的致突变作用。实验结果表明JX-1对小鼠精子总数、精子活动率及精子畸形率均无统计学意义的增加,与小鼠睾丸DNA合成抑制试验阴性反应一致。作者认为JX-1对雄性生殖细胞为一种非诱变剂。  相似文献   
29.
曹维  赵德化 《医学争鸣》1989,10(6):405-408
采用细胞内微电极记录技术,同步观察了3,6-[二甲氨基]-二苯并碘因甲酸盐(IHC-64)对豚鼠心乳头肌细胞动作电位和收缩力的作用。50μmol/L IHC-64抑制心肌收缩力,而不影响快反应动作电位。增加IHC-64浓度,动作电位0相最大峰值(APA)、除极速率(dp/dt_(max))和复极50%和90%时程(APD_(50)、APD_(90))被明显抑制。IHC-64抑制慢反应动作电位,提高细胞外钙浓度可拮抗这种抑制。结果提示,IHC-64主要抑制慢Ca~(2+)内流,同时也部分抑制快Na~+内流,它可能是一种新型B类钙通道阻滞剂。  相似文献   
30.
中专学生的自杀态度与自杀行为的研究   总被引:3,自引:0,他引:3  
目的:探讨不同民族、年级和性别的中专学生对自杀态度的认识;对不同的自杀态度的认识对自杀意念、自杀计划和自杀企图的影响.方法:以某市两所中专学校共2032名中专学生作为调查对象进行现况调查.自杀行为的定义与问卷设计与美国CDC青年危险行为监测系统(YRBSS)相同.结果:不同民族、性别和年级的中专生对自杀态度有所不同;中专生对自杀行为性质的认识和对安乐死的态度影响自杀行为的发生.结论:加强中专生对自杀的认识有助预防中专生自杀行为的发生.  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