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   126249篇
  免费   10705篇
  国内免费   8168篇
耳鼻咽喉   1021篇
儿科学   1562篇
妇产科学   2323篇
基础医学   14817篇
口腔科学   2061篇
临床医学   16421篇
内科学   20679篇
皮肤病学   1448篇
神经病学   6876篇
特种医学   4297篇
外国民族医学   70篇
外科学   13108篇
综合类   18933篇
现状与发展   24篇
一般理论   5篇
预防医学   7817篇
眼科学   3655篇
药学   12803篇
  115篇
中国医学   6052篇
肿瘤学   11035篇
  2024年   348篇
  2023年   1828篇
  2022年   4669篇
  2021年   5887篇
  2020年   4233篇
  2019年   4089篇
  2018年   4130篇
  2017年   3690篇
  2016年   3462篇
  2015年   5216篇
  2014年   6537篇
  2013年   6094篇
  2012年   8908篇
  2011年   9766篇
  2010年   5952篇
  2009年   4734篇
  2008年   6509篇
  2007年   6500篇
  2006年   6542篇
  2005年   6486篇
  2004年   4459篇
  2003年   4213篇
  2002年   3559篇
  2001年   3223篇
  2000年   3311篇
  1999年   3448篇
  1998年   2243篇
  1997年   2168篇
  1996年   1564篇
  1995年   1457篇
  1994年   1266篇
  1993年   819篇
  1992年   1227篇
  1991年   1075篇
  1990年   931篇
  1989年   823篇
  1988年   712篇
  1987年   669篇
  1986年   508篇
  1985年   463篇
  1984年   249篇
  1983年   178篇
  1982年   118篇
  1981年   116篇
  1980年   76篇
  1979年   120篇
  1978年   59篇
  1976年   52篇
  1975年   55篇
  1974年   65篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
综合、改良了分别分型的方法,建立了红细胞同工酶ADA一EAP一AK1同步电泳分型方法,为ADA,EAP和AK13种红细胞同工酶在法医学鉴定中更广泛的应用,提供了一种可靠、经济、实用的方法。  相似文献   
92.
目的探讨健康教育在青光眼患者中的应用,并评价其实施效果。方法利用个体指导、健康处方、集体授课的形式,采取讲授、示范和操作的方法,对84例青光眼患者进行疾病知识、眼压监测、饮食、生活、运动等方面的健康教育。结果实施健康教育前患者知识掌握的优良率为28.6%,而实施健康教育后为80.9%,(P<0.05);实施健康教育后学会控制不良情绪、自我监测眼压、眼球按摩、正确使用降眼压眼水的人数比以前增多(P<0.05)。结论健康教育能提高青光眼患者的疾病知识水平和自我护理水平及监查依从性。  相似文献   
93.
We investigated airway response to propranolol in 48 asthmatics, 17 subjects with chronic bronchitis and 19 normal subjects. The positive rate for propranolol challenge was 93.8% in asthma group, 5.9% in chronic bronchitis group while none in normal group had positive response. The challenge was highly reproducible, and it had few side-effects. This indicated that the challenge was specific and sensitive in diagnosis of asthma, it was a safe, reliable method of measuring non-specific airway responsiveness. Furthermore we also demonstrated that PC20 for propranolol did not relate to PC20 for methacholine, and that the calibre of airway did not significantly influence the airway response to propranolol.  相似文献   
94.
婴儿先天性胆总管囊肿16例诊治分析   总被引:6,自引:0,他引:6  
1985 ̄1994年作者单位共收治小儿先天性胆总管囊肿105例,其中年龄小于12个月者16例,占15.2%,本病临床表现不典型,易延误诊治,超声检查可在产前检出本病,作者认为对于待续性黄疸的婴儿,保守治疗不宜时间过长,应积极手术探查。  相似文献   
95.
观测了急性肝炎和重症肝炎病人血浆VitE及Lpo水平及其动态变化。急性肝炎和重症肝炎病人血浆VitE低于对照组,Lpo高于对照组,均以重症肝炎更明显,且死亡病例血浆VitE低于存活者。部份病人口服VitE不能提高其血浆水平,并随病情加重而逐渐降低。讨论了病毒性肝炎病人血浆VitE降低与Lpo升高的关系及其临床意义,认为动态观测血浆VitE可作为判断重症肝炎病情进展及预后的参考。  相似文献   
96.
NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images.  相似文献   
97.
药物不良反应国内文献题录检索系统   总被引:2,自引:0,他引:2  
本文报道了药物不良反应国内文献题录检索系统的设计原理、功能特点,以输入药名及不良反应类别为例,显示了检索系统操作简便,提供信息及时准确的特点。本系统可从药名、不良反应类别及作者等多方面进行检索,可为查询者提供所需的详细资料,弥补了人工查阅文献的不足。并将继续扩大文献资料库,由题录向电报文体文摘形式转化,以贮存更多的信息。  相似文献   
98.
本文从理论上提出了红细胞沉降速度的准确概念,阐明了红细胞沉降过程所包含的物理和生理信息,提出了一种新型测量红细胞沉降速度及其它特征参数的方法,并给出了其主体、硬件和软件设计要点。  相似文献   
99.
The relation between the amplitude of visual responses to a checkerboard stimulus and the degree of lateral displacement of the checks was examined across different check sizes with simultaneously recorded electroretinograms (ERGs) and visual-evoked potentials (VEPs). The amplitudes of both the b-wave and the after-potential of the ERG increase linearly with pattern displacement. However, the major components of the VEP (N70 and P100) were smaller than expected from linearity for both small checks with small displacements (thresholding) and for large checks with large displacements (saturation). These results suggest that the ERG is proportional to the number of receptors stimulated, but the VEP reflects neural processes influenced by the spatial structure of the stimulus.  相似文献   
100.
Summary To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transeatheter laser and electrical energy on ventricle, 33 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature beats and 86 % of them occurred within the first minute after energy discharged, while ventricular tachycardias were found in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5 % and 13 % respectively (P< 0.01): 4) A decrease in aortic blood pressure and an increase in central verous pressure induced by laser ablation were significantly less than that produced by the same amount of electrical energy (P<0.0l). Our preliminary results have shown that transeatheter laser ablation has great potential for becoming a practical method in the management of refractory tachycardias.  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