全文获取类型
收费全文 | 126991篇 |
免费 | 10785篇 |
国内免费 | 8208篇 |
专业分类
耳鼻咽喉 | 1034篇 |
儿科学 | 1566篇 |
妇产科学 | 2326篇 |
基础医学 | 14901篇 |
口腔科学 | 2071篇 |
临床医学 | 16508篇 |
内科学 | 20763篇 |
皮肤病学 | 1450篇 |
神经病学 | 6897篇 |
特种医学 | 4332篇 |
外国民族医学 | 70篇 |
外科学 | 13212篇 |
综合类 | 19064篇 |
现状与发展 | 24篇 |
一般理论 | 5篇 |
预防医学 | 7859篇 |
眼科学 | 3666篇 |
药学 | 12896篇 |
116篇 | |
中国医学 | 6105篇 |
肿瘤学 | 11119篇 |
出版年
2024年 | 351篇 |
2023年 | 1843篇 |
2022年 | 4712篇 |
2021年 | 5946篇 |
2020年 | 4257篇 |
2019年 | 4127篇 |
2018年 | 4153篇 |
2017年 | 3727篇 |
2016年 | 3485篇 |
2015年 | 5260篇 |
2014年 | 6602篇 |
2013年 | 6139篇 |
2012年 | 8966篇 |
2011年 | 9821篇 |
2010年 | 5979篇 |
2009年 | 4781篇 |
2008年 | 6549篇 |
2007年 | 6529篇 |
2006年 | 6569篇 |
2005年 | 6506篇 |
2004年 | 4482篇 |
2003年 | 4226篇 |
2002年 | 3581篇 |
2001年 | 3233篇 |
2000年 | 3323篇 |
1999年 | 3465篇 |
1998年 | 2248篇 |
1997年 | 2176篇 |
1996年 | 1567篇 |
1995年 | 1464篇 |
1994年 | 1274篇 |
1993年 | 824篇 |
1992年 | 1227篇 |
1991年 | 1078篇 |
1990年 | 932篇 |
1989年 | 824篇 |
1988年 | 712篇 |
1987年 | 669篇 |
1986年 | 510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 0 毫秒
101.
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
102.
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
103.
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
104.
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
105.
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
106.
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
107.
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
108.
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
109.
30余种氨基酸、40余种非挥发性有机酸和20余种碱基核苷类化合物在一块薄层板上完成多相同步色谱分析;用紫外灯-吖啶试剂-镉茚三酮试剂实行组合显色定位分析。改善了尿液中非挥发性有机酸的溶剂萃取法,尿中三类化合物提取物的同步多相色谱分离效果良好。 相似文献
110.
吴国娟 《临床心身疾病杂志》2003,9(3):166-167
目的 了解司法鉴定中精神病患者反复上访原因。方法 对诊断为无精神病者与诊断为精神病偏执型人格障碍、偏执性精神病、精神分裂症者的上访诱因、动机、目的、内容、时间、形式、有否过激行为等进行比较。结果 上访诱因、动机、目的等方面以生活、工作、经济问题为主;上访时间以患病5—20a者居多。共33例(71.73%):上访者中有过激行为者21例(45.65%)。结论 精神病患者上访者中以偏执型人格障碍、偏执性精神病、精神分裂症居多。其特点与正常人有所区别。这就要求政府部门在接待上访者及处理上访问题时。应加以严格区分并正确、合理解决上访要求。以免产生不良的社会问题。 相似文献