全文获取类型
收费全文 | 283973篇 |
免费 | 25677篇 |
国内免费 | 8988篇 |
专业分类
耳鼻咽喉 | 3281篇 |
儿科学 | 6615篇 |
妇产科学 | 3824篇 |
基础医学 | 22161篇 |
口腔科学 | 7324篇 |
临床医学 | 26218篇 |
内科学 | 39877篇 |
皮肤病学 | 2663篇 |
神经病学 | 10698篇 |
特种医学 | 8466篇 |
外国民族医学 | 27篇 |
外科学 | 37130篇 |
综合类 | 46038篇 |
现状与发展 | 29篇 |
一般理论 | 25篇 |
预防医学 | 31417篇 |
眼科学 | 2032篇 |
药学 | 27441篇 |
371篇 | |
中国医学 | 30295篇 |
肿瘤学 | 12706篇 |
出版年
2024年 | 1219篇 |
2023年 | 5916篇 |
2022年 | 10621篇 |
2021年 | 14174篇 |
2020年 | 13415篇 |
2019年 | 14441篇 |
2018年 | 13018篇 |
2017年 | 11691篇 |
2016年 | 11232篇 |
2015年 | 10491篇 |
2014年 | 19221篇 |
2013年 | 19702篇 |
2012年 | 16795篇 |
2011年 | 18237篇 |
2010年 | 14634篇 |
2009年 | 12975篇 |
2008年 | 12339篇 |
2007年 | 12342篇 |
2006年 | 10936篇 |
2005年 | 9199篇 |
2004年 | 7560篇 |
2003年 | 6659篇 |
2002年 | 5356篇 |
2001年 | 4621篇 |
2000年 | 3949篇 |
1999年 | 3218篇 |
1998年 | 2748篇 |
1997年 | 2419篇 |
1996年 | 2084篇 |
1995年 | 1907篇 |
1994年 | 1771篇 |
1993年 | 1507篇 |
1992年 | 1395篇 |
1991年 | 1258篇 |
1990年 | 1070篇 |
1989年 | 1012篇 |
1988年 | 922篇 |
1987年 | 820篇 |
1986年 | 742篇 |
1985年 | 1999篇 |
1984年 | 2263篇 |
1983年 | 1414篇 |
1982年 | 1869篇 |
1981年 | 1320篇 |
1980年 | 1123篇 |
1979年 | 1024篇 |
1978年 | 836篇 |
1977年 | 641篇 |
1976年 | 787篇 |
1975年 | 522篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
71.
A. G. D. Maran J. A. Wilson M. N. Gaze 《European archives of oto-rhino-laryngology》1993,250(3):127-132
Summary Squamous cell carcinoma of the head and neck is a disease predominantly of males and is due to a variety of known environmental irritants, notably cigarette smoke. Dietary, viral and immunological factors may also be relevant. Head and neck squamous cancers express epidermal growth factor receptors and some show weak levels of oestrogen receptor activity, but a reliable serum marker of tumour burden remains to be identified. The prognosis is found to be less favourable in females, in those with advanced T stage, in association with multiple node involvement, especially where extracapsular spread is present and where the T4/T8 ratio is elevated. Administration of heterologous blood during therapy may also have an adverse effect on prognosis. Interested clinicians must remember that most cases are preventable.
Correspondence to: A.G.D. Maran 相似文献
72.
73.
This report describes a model for identifying sets of teaching abilities considered to be effective for medical school teaching staff, based on roles teachers assume and functions they are expected to perform as instructors. The specification of these teaching abilities was the first step in the development of a comprehensive course on Medical Instruction at the Basic Institute of Medical and Agricultural Biology of the State University of Sao Paulo, Botucatu, Brazil, where the senior author is employed. The work was based on the assumption that medical school teachers are expected to assume a variety of teaching roles and that identification and specification of the abilities that define their roles can result in more effective and efficient teaching. 相似文献
74.
75.
The role of infection and vaccination in the genesis of optic neuritis and multiple sclerosis in children 总被引:2,自引:0,他引:2
R. Riikonen 《Acta neurologica Scandinavica》1989,80(5):425-431
This article describes the association between previous infection and/or vaccination and the development of optic neuritis (ON) in 18 children. Ten of these children subsequently developed clinically definite multiple sclerosis (MS), while in 8 patients a clinically definite etiology could not be confirmed. Vaccination preceded the first ON attack in 6 patients, all but one of whom subsequently developed MS. It also preceded subsequent demyelinating events in 6 patients. Ten of the patients had a bacterial or viral infection within the 2 weeks prior to the first symptoms of ON. Intrathecal antibody synthesis against 2 or more viruses could be shown in 5 out of 8 patients studied; 5 out of 6 patients had oligoclonal antibodies in CSF and 12 out of 16 patients a high IgG index. Neither intrathecal antibody synthesis against 2 or more viruses nor elevated IgG indexes could be found in the control patients. Measles and mumps occurred at a significantly later age in the children who subsequently developed MS than in the control children, and these patients had significantly more events that might have impaired the blood-brain barrier than the controls. These results indicate that immunological events leading to MS may be triggered during childhood. Vaccination and infection often precede ON in childhood. Intrathecal viral antibody production can occur already in childhood at the time of the first symptoms of MS. 相似文献
76.
Zongli Lin Meir Pachter Siva Banda Yacov Shamash 《Optimal control applications & methods.》2002,23(1):21-43
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
77.
Poncet病(病例报告及文献复习) 总被引:4,自引:0,他引:4
目的 探讨Poncet病的诊断与治疗。方法 通过病例报告及献复习,综述了Poncet病的发病机理、临床表现。结果 提高对Poncet病的认识。结论 临床上对风湿性或类风湿性关节炎病人均应与本病鉴别。 相似文献
78.
目的 探讨严重创伤后肝细胞凋亡及坏死在急性肝功能障碍发病机制中的作用。方法复制多发性骨折合并休克的大鼠创伤模型,采用 Annexin-V-Flous、碘化丙锭(propidium iodid,PI)双标法经流式细胞仪检测创伤后各时间点肝细胞凋亡与坏死的数量变化,结合光镜、电镜和电泳观察细胞凋亡与坏死,并与肝功能变化相比较。结果创伤后早期肝细胞即发生凋亡和坏死,坏死肝细胞的数量进行性升高,与肝功能变化显著呈正相关;凋亡肝细胞在创伤后3h达高峰,部分凋亡肝细胞发生继发性坏死,其数量与肝功能变化显著正相关。结论肝细胞坏死与凋亡是严重创伤后肝功能损害的重要原因,坏死肝细胞是肝功能损害的直接因素,凋亡肝细胞通过发生继发性坏死加重肝功能损害。 相似文献
79.
朱平 《南方医科大学学报》2002,22(9):861-861
报告1例严重胸腹部闭合性联合伤所致的急性呼吸心跳骤停得到成功救治的病例。闭合性胸腹联合伤后,因病情可能发展,应随时注意复查胸片、血气等;若基层医院条件不够,应及时转往上级医院,以免延误患者的治疗。 相似文献
80.