全文获取类型
收费全文 | 256049篇 |
免费 | 9206篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 2301篇 |
儿科学 | 9067篇 |
妇产科学 | 4788篇 |
基础医学 | 28104篇 |
口腔科学 | 3527篇 |
临床医学 | 22357篇 |
内科学 | 45019篇 |
皮肤病学 | 1944篇 |
神经病学 | 22960篇 |
特种医学 | 11607篇 |
外国民族医学 | 10篇 |
外科学 | 39901篇 |
综合类 | 3958篇 |
一般理论 | 67篇 |
预防医学 | 27346篇 |
眼科学 | 4563篇 |
药学 | 16069篇 |
1篇 | |
中国医学 | 700篇 |
肿瘤学 | 21123篇 |
出版年
2021年 | 1142篇 |
2020年 | 753篇 |
2019年 | 1156篇 |
2018年 | 23143篇 |
2017年 | 18224篇 |
2016年 | 20494篇 |
2015年 | 2121篇 |
2014年 | 2406篇 |
2013年 | 3301篇 |
2012年 | 10304篇 |
2011年 | 24558篇 |
2010年 | 20642篇 |
2009年 | 13331篇 |
2008年 | 22559篇 |
2007年 | 25014篇 |
2006年 | 3883篇 |
2005年 | 5545篇 |
2004年 | 6536篇 |
2003年 | 7278篇 |
2002年 | 5374篇 |
2001年 | 2965篇 |
2000年 | 3219篇 |
1999年 | 2652篇 |
1998年 | 1249篇 |
1997年 | 1067篇 |
1996年 | 942篇 |
1995年 | 870篇 |
1994年 | 896篇 |
1993年 | 790篇 |
1992年 | 2129篇 |
1991年 | 2099篇 |
1990年 | 2018篇 |
1989年 | 1931篇 |
1988年 | 1813篇 |
1987年 | 1812篇 |
1986年 | 1702篇 |
1985年 | 1688篇 |
1984年 | 1403篇 |
1983年 | 1275篇 |
1982年 | 861篇 |
1981年 | 713篇 |
1980年 | 674篇 |
1979年 | 1214篇 |
1978年 | 880篇 |
1977年 | 763篇 |
1976年 | 721篇 |
1975年 | 718篇 |
1974年 | 878篇 |
1973年 | 753篇 |
1972年 | 734篇 |
排序方式: 共有10000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.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
4.
5.
6.
7.
8.
In 1963, Goffman argued that forming a group based on shared stigma may provide benefits. However, there is no empirical research on whether perception that a separate, unique, coherent group exists (i.e., group entitativity) influences coping, such as educating others or secrecy, for the stigmatized individual or his or her spouse. Further, little is known about how spouses influence each other in terms of promoting the education of others about a stigmatizing condition, especially when it comes to the role of believing that stigma-based groups, to which they may both belong, exist. This study provides a step toward bridging this gap in the research by applying the label management model in efforts to understand coping for couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). This study included 50 married couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). We found that group entitativity related to those with AATD counterbalanced the influence of genetic stigma on spouses’ intentions to keep the diagnosis secret or to educate others about it. Intrapersonal and interpersonal influences appeared among spouses. Attention is needed on the power of creating groups for stigmatized persons and their relatives. Indeed, people live within a dynamic world of group entities, and multiple social identities including spousal and familial. While attention has been paid to the diffusion of stigmas to loved ones, less has been paid to the uplift of group entities for them. 相似文献
9.
10.