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   42610篇
  免费   3546篇
  国内免费   744篇
耳鼻咽喉   150篇
儿科学   602篇
妇产科学   326篇
基础医学   4163篇
口腔科学   794篇
临床医学   4713篇
内科学   6497篇
皮肤病学   210篇
神经病学   2916篇
特种医学   1350篇
外国民族医学   2篇
外科学   3224篇
综合类   4249篇
现状与发展   4篇
一般理论   1篇
预防医学   8547篇
眼科学   382篇
药学   4522篇
  42篇
中国医学   2285篇
肿瘤学   1921篇
  2024年   122篇
  2023年   710篇
  2022年   1180篇
  2021年   1818篇
  2020年   2006篇
  2019年   1474篇
  2018年   1371篇
  2017年   1523篇
  2016年   1481篇
  2015年   1497篇
  2014年   3252篇
  2013年   3359篇
  2012年   2766篇
  2011年   2966篇
  2010年   2301篇
  2009年   2224篇
  2008年   2126篇
  2007年   1972篇
  2006年   1778篇
  2005年   1437篇
  2004年   1202篇
  2003年   1115篇
  2002年   924篇
  2001年   740篇
  2000年   592篇
  1999年   494篇
  1998年   407篇
  1997年   400篇
  1996年   343篇
  1995年   330篇
  1994年   262篇
  1993年   262篇
  1992年   218篇
  1991年   193篇
  1990年   212篇
  1989年   179篇
  1988年   186篇
  1987年   164篇
  1986年   160篇
  1985年   204篇
  1984年   170篇
  1983年   118篇
  1982年   128篇
  1981年   113篇
  1980年   107篇
  1979年   63篇
  1978年   53篇
  1977年   39篇
  1976年   56篇
  1975年   28篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Several studies have demonstrated that a descending dopaminergic pathway innervates the dorsal and the intermediate gray matter of the spinal cord and have suggested that this pathway is involved in pain modulation and in the control of autonomie functions. Other studies have also demonstrated the presence of dopamine (DA) and DA metabolites as well as of DA receptors in the ventral cord. There is also evidence for the implication of DA in the control of motor functions at the spinal level. The occurrence of a dopaminergic innervation in the ventral horn has been, however, disputed until recently. But recent work has demonstrated that the motoneural cell groups in the ventral horn (lamina IX) are a target for descending dopaminergic fibers. In addition, the possibility that DA is a mediator of primary afferent fibers has also been postulated. Finally, the occurrence of dopaminergic cell bodies has been suggested in the spinal cord. This indicates that DA is probably implicated in a complex manner in spinal functions. In the present paper the possible involvement of DA in sensory and in motor functions at spinal level will be discussed in view of neurochemical observations made in polyarthritic rats, in which pain-related behavior and reduction of locomotor activity associated with a marked decrease in mobility, are observed.  相似文献   
52.
A feasibility study was undertaken to evaluate laboratory phlebotomists performing bedside glucose monitoring (BGM) over a 3-month period on a medical and surgical floor. Specific questions included: feasibility of providing testing on a 24-h basis, accuracy, appropriate utilization, effect on patient care, and an analysis of cost. In all, 1975 tests were performed on 114 patients. BGM results were within 15% of the laboratory's result 97% of the time. Patient and physician satisfaction was high. Although the cost of BGM is slightly higher than a laboratory glucose test, its use appeared to reduce the length of hospital stay by 0.47 days. Practical information on initiating a highly successful BGM program is provided.  相似文献   
53.
The “restricted areas” provisions of the Northern Territory Liquor Act constitute a preventative policy aimed at reducing the effects of alcohol abuse, particularly on Aboriginal communities. Under the provisions, communities can apply to be declared “dry” or semi-restricted with respect to liquor. Since their inception in 1979, the provisions have given rise to continuing controversy. This paper addresses some of the issues associated with the controversy. Patterns of alcohol consumption on “dry”, semi-restricted and unrestricted communities are compared, and the incidence of apprehension for public drunkenness before and after restricted area declarations is examined. The paper also discusses the provisions under which vehicles implicated in acts of illicit “grog-running” are forfeited to the NT Government. It is concluded that the restricted area provisions are associated with reduced levels of alcohol consumption and apprehensions for drunkenness, and are therefore beneficial in outcome. However, it is also argued that at present the provisions are flawed in that, while some aspects serve to promote community control over alcohol consumption, other elements have the effect of undermining community control and responsibility.  相似文献   
54.
55.
调整给药时间减轻顺铂肾毒性的研究   总被引:7,自引:0,他引:7  
目的 观察不同给药时间对顺铂肾毒性的影响。 方法  1 6例癌症患者分为两组各 8例 ,分别在上午 1 0时或下午 8时静滴 6 0mg m2 顺铂 ,3~ 4周后作第 2周期化疗时交换给药时间 ,以尿 β2 微球蛋白浓度作为肾小管功能改变的指标。 结果 治疗前两组的尿 β2 微球蛋白浓度均在 2 0 0 μg L以下。治疗后 ,上午 1 0时给药组的尿β2 微球蛋白浓度在第 1周期为 4 96± 6 6 μg L ,第 2周期为 5 0 4± 74 μg L ,下午 8时给药组分别为 2 77± 4 3μg L(t=3.6 6 ,P <0 .0 1 )和 2 83± 39μg L(t=3.6 3,P <0 .0 1 )。  结论 不同时间给药对顺铂的肾毒性有显著影响 ,下午 8时给药可明显减轻顺铂的肾毒性。  相似文献   
56.
一种有效去除脂血对血清多种生化指标测定干扰的方法   总被引:1,自引:0,他引:1  
目的 :探讨一种去除脂血对血清生化项目测定干扰的方法。方法 :沉淀、离心沉淀去除血清中过量的乳糜微粒。结果 :该法简便去脂效果彻底 ,不影响测定结果。结论 :获得了一种满意的去脂方法  相似文献   
57.
TOPIC: The power relations between involuntarily hospitalized adolescents and their caregivers from the viewpoint of theory development in nursing and the concept of medicalization. PURPOSE: To contribute to the development of nursing theories that can guide nursing care of involuntarily hospitalized adolescents by examining the power relations between the adolescents and their caregivers. SOURCES: Published literature in medical sociology, and nursing and psychiatric ethics. Nursing and psychiatric literature, in which Michel Foucault's theories are used to explicate the disciplinary power of psychiatry. CONCLUSIONS: To empower involuntarily hospitalized adolescents nurses must both recognize the inevitable power imbalance and seek guidance from the egalitarian ideals of nursing. Nurses can draw from postmodern thinkers who dismiss the idea that one theory can explain human relationships.  相似文献   
58.
A design technique (Control of Uncertain Systems with Bounded Inputs, Tarbouriech S, Garcia G, (Eds), Lecture Notes in Control and Information Sciences, vol. 227 , Springer: Berlin, 1997; 173–186) recently proposed for stabilization of a linear system with rate‐limited actuators is utilized to design feedback laws that cause the system output to track a desired command signal. This design technique combines two design techniques recently developed for linear systems with position limited actuators, piecewise‐linear LQ control (Automatica, 1994; 30 : 403–416) and low‐and‐high gain feedback (IEEE Trans. Automat. Control, 1996; 41 : 368–378), and hence takes advantage of both design techniques, while avoiding their disadvantages. In the case that only the output is available for feedback, the performance of the state feedback law is preserved by the use of a fast observer. An open‐loop exponentially unstable fighter aircraft is used to demonstrate the effectiveness of the proposed control design method. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
59.
目的 :制备罂硝软膏 ,并建立质量控制方法。方法 :以硝酸甘油、盐酸罂粟碱、双氯芬酸钾为主药研制软膏剂 ,用紫外分光光度法及酸碱滴定法分别测定硝酸甘油、盐酸罂粟碱、双氯芬酸钾3组分的含量。结果 :硝酸甘油、盐酸罂粟碱、双氯芬酸钾的平均回收率分别为100 65 %、99 86 %、100 55 %,相对标准差分别为0 4945 %、0 1719 %、0 3205 %(n=3)。结论 :该软膏制备工艺可行 ,质量可控 ,性质稳定。  相似文献   
60.
血糖水平对18F-FDG PET/CT图像质量的影响   总被引:1,自引:0,他引:1  
目的 研究血糖水平对18F-脱氧葡萄糖(FDG) PET/CT图像质量的影响.方法 80例行体格检查或评价肿瘤性质的受检者,按空腹血糖水平分为9组(组间距为1mmol/L),第1组为血糖正常组,即血糖<6.0mmol/L(10例);第2~9组血糖水平高于正常,分别为6.0~6.9mmol/L(11例),7.0~7.9mmol/L(13例),8.0~8.9mmol/L(11例),9.0~9.9mmol/L(11例),10.0~10.9mmol/L(8例),11.0~11.9mmol/L(6例),12.0~12.9mmol/L(5例),≥13.0mmol/L(5例).受检者做完PET/CT检查后,图像质量由2位有经验的医师独立判断.同时根据肝不同层面的标准摄取值(SUV)最大值(SUVmax)及SUV平均值(SUVavg)分别计算肝图像噪声.采用SPSS 12.0软件进行统计学处理.结果 (1)9组之间图像质量评分、肝噪声差异有统计学意义(P均<0.05).将第2~9组图像质量评分、肝噪声分别与第1组进行比较,第2~7组与第1组差异无统计学意义(P均>0.05);第8,9组与第1组比较差异有统计学意义(P均<0.05),且评分低于第1组.(2)血糖水平与图像质量评分呈负相关(r=-0.52,P<0.05);血糖水平与肝噪声呈正相关(SUVmax、SUVavgr值分别为0.33和0.60,P均<0.05);SUVavg所算噪声与血糖水平的相关性优于SUVmax.结论 图像质量随血糖水平的升高而下降,血糖<12.0mmol/L时与血糖正常者PET/CT图像质量差异无统计学意义,但当血糖水平≥12.0mmol/L时图像质量将显著下降.  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