全文获取类型
收费全文 | 6798篇 |
免费 | 486篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 152篇 |
妇产科学 | 131篇 |
基础医学 | 999篇 |
口腔科学 | 79篇 |
临床医学 | 773篇 |
内科学 | 1554篇 |
皮肤病学 | 115篇 |
神经病学 | 513篇 |
特种医学 | 636篇 |
外国民族医学 | 9篇 |
外科学 | 739篇 |
综合类 | 83篇 |
一般理论 | 1篇 |
预防医学 | 314篇 |
眼科学 | 270篇 |
药学 | 339篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 465篇 |
出版年
2022年 | 36篇 |
2021年 | 72篇 |
2020年 | 59篇 |
2019年 | 74篇 |
2018年 | 94篇 |
2017年 | 85篇 |
2016年 | 74篇 |
2015年 | 104篇 |
2014年 | 146篇 |
2013年 | 185篇 |
2012年 | 254篇 |
2011年 | 284篇 |
2010年 | 195篇 |
2009年 | 174篇 |
2008年 | 259篇 |
2007年 | 299篇 |
2006年 | 224篇 |
2005年 | 270篇 |
2004年 | 235篇 |
2003年 | 229篇 |
2002年 | 214篇 |
2001年 | 205篇 |
2000年 | 208篇 |
1999年 | 177篇 |
1998年 | 148篇 |
1997年 | 126篇 |
1996年 | 133篇 |
1995年 | 123篇 |
1994年 | 91篇 |
1993年 | 78篇 |
1992年 | 134篇 |
1991年 | 133篇 |
1990年 | 140篇 |
1989年 | 154篇 |
1988年 | 152篇 |
1987年 | 139篇 |
1986年 | 142篇 |
1985年 | 135篇 |
1984年 | 99篇 |
1983年 | 100篇 |
1982年 | 80篇 |
1981年 | 81篇 |
1980年 | 76篇 |
1979年 | 76篇 |
1978年 | 58篇 |
1977年 | 62篇 |
1976年 | 68篇 |
1975年 | 55篇 |
1974年 | 37篇 |
1972年 | 32篇 |
排序方式: 共有7300条查询结果,搜索用时 15 毫秒
1.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome. 相似文献
2.
3.
A new strategy to yield information from the maximum number of voxels, each at the optimum signal-to-noise ratio (SNR) per unit time, in MR spectroscopic imaging (MRSI) is introduced. In the past, maximum acquisition duty-cycle was obtained by multiplexing in time several single slices each repetition time (TR), while optimal SNR was achieved by encoding the entire volume of interest (VOI) each TR. We show that optimal SNR and acquisition efficiency can both be achieved simultaneously by multiplexing in space and time several slabs of several slices, each. Since coverage of common VOIs in 3D proton MRSI in the human brain typically requires eight or more slices, at 3 T or higher magnetic fields, two or more slabs can fit into the optimum TR (approximately 1.6 s). Since typically four or less slices would then fit into each slab, Hadamard encoding is favored in that direction for slice profile reasons. It is demonstrated that per fixed examination length, the new method gives, at 3 T, twice as many voxels, each of the same SNR and size, compared with current 3D chemical shift imaging techniques. It is shown that this gain will increase for more extensive spatial coverage or higher fields. 相似文献
4.
5.
N-Hydroxythalidomide (1d), a potential metabolite of thalidomide (1a), was synthesized from N-phthalyglutaminic acid anhydride (1b) and O-tetrahydropyraline hydroxylamine, followed by deprotection. The teratogenicity of 1d was studied using the Hen's-Egg-Test model which had been found applicable for 1a. 1d was more teratogenic to chicken embryos compared to 1a. The percentage of teratogenic malformations in the 1d groups was 28-46%, whereas the percentage in the 1a groups was 20-23%. The oxygen protected precursor N-hydroxythalidomide (1c) was less teratogenic (11-15%). 相似文献
6.
1-Methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH3-MPTP) is a more potent dopaminergic neurotoxin than MPTP in mice 总被引:1,自引:0,他引:1
S K Youngster R C Duvoisin A Hess P K Sonsalla M V Kindt R E Heikkila 《European journal of pharmacology》1986,122(2):283-287
The administration to mice of 1-methyl-4-(2'-methylphenyl)-1,2,3, 6-tetrahydropyridine (2'-CH3-MPTP), a substituted analog of the dopaminergic neurotoxin MPTP caused even more dopaminergic toxicity than MPTP itself. Under conditions in which MPTP was relatively ineffective (i.e. two injections per day of 0.113 mmol/kg at an interval of 6 h for one or two days), 2'-CH3-MPTP caused a very large decrement in the neostriatal content of dopamine and its metabolites and a corresponding decrement in the capacity of a neostriatal synaptosomal preparation to take up [3H]dopamine. Moreover, 2'-CH3-MPTP administration (as few as four injections) caused a virtually complete loss of nerve cells in the zona compacta of the substantia nigra. This compound, like MPTP, may prove to be a valuable research tool. 相似文献
7.
RA O. Hempel 《Notfall & Rettungsmedizin》2007,10(5):367-371
Legal uncertainties for emergency vehicle drivers can be avoided when fundamental rules are established. In particular, differentiation of special rights and rights of way is essential. Inherent in both is the urgency necessary to save human lives. The right of way signaled by flashing blue lights and siren does not however justify traffic violations but signifies rather a request to other traffic participants. In contrast, special rights require no announcement and constitute a justifiable reason for traffic violations. Even so they do not allow that other traffic participants be endangered or harmed. Adherence to these basic principles can prevent legal misinterpretations as well as rigid adoption of inflexible standards of behavior. 相似文献
8.
RA Mag. Dr. C. Gepart 《Notfall & Rettungsmedizin》2007,10(4):289-292
Austria’s new Living Wills Act (Patientenverfügungsgesetz, or PatVG) that came into effect on 1st of June 2006, is the first law in Austria to regulate the controversial issue of living wills. The PatVG provides for a right to refuse future medical treatment by making an advance directive in the form of a living will that is either binding or “to be taken into consideration”. However, the establishment of a binding living will is governed by strict criteria as regards form and content, and both a medical doctor and a legal expert must be involved. Compliance with a living will is not allowed where there is a legal obligation to give medical treatment. There is also a legal obligation to give medical treatment in emergency situations where the time involved in looking for a living will could seriously endanger the health or the life of a patient. 相似文献
9.
10.
Ohne Zusammenfassung 相似文献