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   98781篇
  免费   11179篇
  国内免费   6146篇
耳鼻咽喉   1076篇
儿科学   1434篇
妇产科学   628篇
基础医学   8526篇
口腔科学   2302篇
临床医学   12019篇
内科学   10428篇
皮肤病学   938篇
神经病学   3423篇
特种医学   3857篇
外国民族医学   28篇
外科学   9604篇
综合类   24247篇
现状与发展   26篇
一般理论   6篇
预防医学   9735篇
眼科学   1970篇
药学   11092篇
  180篇
中国医学   8541篇
肿瘤学   6046篇
  2025年   23篇
  2024年   1619篇
  2023年   1972篇
  2022年   4279篇
  2021年   5301篇
  2020年   4541篇
  2019年   3104篇
  2018年   2897篇
  2017年   3395篇
  2016年   2883篇
  2015年   4618篇
  2014年   5736篇
  2013年   6198篇
  2012年   9132篇
  2011年   9478篇
  2010年   7604篇
  2009年   6574篇
  2008年   7089篇
  2007年   6324篇
  2006年   5638篇
  2005年   4555篇
  2004年   3078篇
  2003年   2523篇
  2002年   1860篇
  2001年   1534篇
  2000年   1333篇
  1999年   765篇
  1998年   354篇
  1997年   312篇
  1996年   272篇
  1995年   225篇
  1994年   164篇
  1993年   131篇
  1992年   107篇
  1991年   90篇
  1990年   91篇
  1989年   63篇
  1988年   52篇
  1987年   51篇
  1986年   36篇
  1985年   28篇
  1984年   16篇
  1983年   12篇
  1982年   6篇
  1981年   6篇
  1980年   4篇
  1979年   5篇
  1978年   4篇
  1976年   3篇
  1975年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
In the past 40 years, the prevalence of eating disorders (ED) in China has shown an increasing trend, leading to an urgent need to develop efficient treatment modes and methods. Since the beginning of the new century, the diagnosis, treatment, and research of ED in China have been under development. This article gives an introduction and commentary on the treatment modes, treatment methods and their applications in ED in China. There are two main treatment forms for ED until now, that is, inpatient treatment and outpatient treatment. Inpatient treatment is recommended as the first choice. Since 2008, clinical psychotherapies such as cognitive behavioral therapy (CBT), dialectical behavioral therapy (DBT), and family-based treatment (FBT), which are effective for pathological symptoms of ED, have been introduced into China and developed clinically. Group CBT and group DBT for patients with ED and group FBT for caregivers might be the most efficient psychotherapy in China nowadays. A multi-family FBT support group could be developed as the basic treatment of ED patients. Although these new types of psychotherapy have observed effectiveness in clinical application, the Randomized Controlled Trials (RCT) are rare and need to be developed.  相似文献   
63.
Previous research in this laboratory, using photoactivatable radioiodinated lipopolysaccharide derivatized with sulfosuccinimidyl-2-(p-azidosalicylamide)-1,3'-dithiopropionate (125I-ASD-LPS), has resulted in the identification of a specific LPS receptor with a molecular mass of approximately 73 kDa on murine lymphocytes and splenic macrophages. The experiments presented in this report investigated whether a similar LPS-binding protein was also expressed on human peripheral blood populations, including monocytes, lymphocytes, neutrophils, platelets, and erythrocytes. Each cell population was incubated with 125I-ASD-LPS, UV irradiated, washed, reduced, and solubilized, and the cell lysates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. On all of the cell populations, except erythrocytes, a similar 73-kDa LPS-binding protein was present. In addition, each population also expressed lower-molecular-weight secondary LPS-binding proteins, some of which were conserved among the populations. Binding of the photoactivatable LPS probe was found to be both time and temperature dependent. These data support the concept that the 73-kDa LPS-binding protein is conserved on multiple cell types from a variety of species.  相似文献   
64.
目的把模式翻转视觉诱发电位快速提取法应用于视神经病变的病人,探讨其临床应用价值。方法应用Galileo视觉诱发电位检测系统对30例正常健康人和17例视神经疾病病人分别进行全视野的PRVEP检测熏每一结果重复检测3次。所得结果应用少次提取法进行处理而得VEP波形。然后将正常对照组3次重复结果两两间分别进行配对t检验,探讨其可重性,并计算出正常值范围,最后参照正常值,分析视神经疾病组的检测结果。结果3次重复结果两两间配对t检验,得P1=0.425>0.05,P2=0.179>0.05,P3=0.110>0.05;参照本研究得出的正常值范围,对病人组的检测结果进行分析,得出这种少次提取法对视神经疾病检测的敏感度90.0%(18/20),特异度92.5%(13/14),准确度91.1%(31/34)。结论用这种少次提取法提取PRVEP,可重性好,稳定可靠。很有临床应用价值。  相似文献   
65.
66.
To assess whether vomitoxin-induced dysregulation of IgA productionand IgA nephropathy are reversible, relevant immunologic parameterswere compared among experimental groups of B6C3F1 mice thatwere fed: (1) 25 ppm vomitoxin in AIN-76A semipurified dietfor 24 weeks (treatment group), (2) 25 ppm vomitoxin for 8 weeksand then control diet for 16 weeks (withdrawal group), and (3)control diet for 24 weeks (control group). Levels of serum IgAand microhematuria index in the treatment group were elevatedafter 4 to 8 weeks and continued to increase with further vomitoxinexposure. IgA immune complexes and mesangial IgA deposition,as quantitated by interactive laser cytometer image analysis,were also increased with toxin exposure at Weeks 8, 16, and24, whereas IgM, IgG, and complement component C3 depositionwere unaffected or depressed. Serum IgA, microhematuria index,and mesangial IgA deposition in withdrawal mice remained elevatedover those of the controls at Weeks 16 and 24 but were lessthan those of the treatment group. Cell recovery from Peyer'spatches (PP) as well as the percentages of IgA+ and CD4+ cellsin PP and spleen at Weeks 16 and 24 were greater in treatmentmice than in controls, but only the percentage of IgA+ cellsin PP was elevated in the withdrawal mice at these the sametime points. When IgA secretion by unstimulated and LPS-stimulatedsplenic lymphocytes was used as the measure of systemic production,it was elevated in both treatment and withdrawal mice at Weeks16 and 24. The results indicated that experimental dysregulationof IgA production and IgA nephropathy persisted up to 4 monthsafter a discrete period of dietary vomitoxin exposure, but thatthe severity of these effects did not increase in a progressivefashion.  相似文献   
67.
Objective To investigate the role of growth hormone-insulin-like growth factor Ⅰ (IGF-Ⅰ) axis in normal pregnancy. Methods Totally, 116 normal pregnant women were recruited from January 1997 to June 1998, with 20 normal nonpregnant women as controls. Maternal growth hormone (GH) and IGF-Ⅰ concentrations were assayed by RIA and enzyme-linked immunosorbent assay, respectively. Results Maternal serum levels of GH increased throughout gestation, reached a peak at 25 weeks of pregnancy and remained fairly high (χ[2]=40.458, P<0.0001).There was a significant difference between samples at 5-9 week gestational age and the controls (3.45 μg/L vs 1.61 μg/L, P<0.05). The maternal serum levels of IGF-Ⅰincreased rapidly throughout gestation from 29-week gestation and reached a peak of 188.86 μg/L at term delivery (χ[2]=50.224, P<0.0001). Conclusions Maternal GH levels increased progressively throughout gestation, which correlated with fetal growth. Maternal GH may regulate nutrition supply among mother, placenta and the fetus and play an important role in transporting nutritional substrates by the placenta. The maternal IGF-Ⅰin the third trimester may promote fetal growth and placental functions.  相似文献   
68.
国产全热解碳双叶瓣的动物实验   总被引:4,自引:0,他引:4  
目的 :探讨人造瓣膜动物实验的方法 ,并对国产瓣的性能作动物体内评价。方法 :体外循环下行羊的二尖瓣替换术 ,先作预实验以确定实验方法 ,后作正式实验。用心导管和超声 ,并用多巴酚丁胺负荷法模拟运动条件 ,分别测定人造瓣的血流动力学参数 ;根据动物存活情况及有无血栓形成和血栓栓塞等评价其生物相容性。结果 :预实验 10只羊均死亡 ,主要与瓣环撕裂有关 ;正式实验 5只羊均存活。术中和术后 2 .5年用导管法测得平均跨瓣压差分别为 0 .69± 0 .2 3k Pa、0 .81± 0 .0 4k Pa;动物尸检未见血栓形成和血栓栓塞。结论 :瓣环撕裂是本组手术主要死亡原因 ,选择适当体重的动物和保留瓣叶的折叠缝补 ,及术后合理的呼吸支持等是实验的关键 ;该国产瓣在动物体内血流动力学和抗血栓性能优良  相似文献   
69.
采用溶剂萃取-化学处理-柱层析相结合的预处理分离程序、色-质联用和色-红联用结合色谱保留值的定性方法,分析研究了内蒙东胜煤快速加氢热解焦油的化学成分和结构,推测鉴定出200多种化合物,并对具有代表性的19种多环芳烃进行了定量分析,讨论了快速加氢热解焦油化学成分的结构特征。  相似文献   
70.
【目的】研制一个计算机辅助的心血管信号检测和处理系统。【方法】本系统的硬件设计采用奔腾 Ⅱ / 2 33多媒体微机系统 ,多路模 /数转换器和心电电极、心音传感器、脉搏波传感器及由运算放大器等构成相关的放大器及滤波器。本系统采用可视化编程环境构建系统结构和功能模块设计的方法 ,基于多媒体技术和小波变换原理 ,在 32位Windows平台下 ,利用可视化编程语言VisualC 6 0和多媒体著作工具Authorware等进行系统的软件设计。【结果】本系统能完成心电、心音、脉搏波信号检测和处理 ,并将结果以图、文、声并茂的形式显示、打印或播放 ,还具有病案管理和心音听诊多媒体计算机辅助教学功能。【结论】它是一个新型的多功能心血管信号检测和处理系统。  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