首页 | 官方网站   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   4217482篇
  免费   331296篇
  国内免费   13861篇
医药卫生   4562639篇
  2021年   55767篇
  2020年   35487篇
  2019年   58452篇
  2018年   73686篇
  2017年   56283篇
  2016年   62323篇
  2015年   75365篇
  2014年   109730篇
  2013年   174868篇
  2012年   120702篇
  2011年   126203篇
  2010年   125236篇
  2009年   126583篇
  2008年   112544篇
  2007年   119869篇
  2006年   128657篇
  2005年   123838篇
  2004年   124107篇
  2003年   114491篇
  2002年   103765篇
  2001年   149702篇
  2000年   144540篇
  1999年   134314篇
  1998年   70103篇
  1997年   66209篇
  1996年   64431篇
  1995年   59699篇
  1994年   53784篇
  1993年   50048篇
  1992年   96054篇
  1991年   92651篇
  1990年   89063篇
  1989年   86829篇
  1988年   80024篇
  1987年   78524篇
  1986年   73858篇
  1985年   72983篇
  1984年   61669篇
  1983年   55434篇
  1982年   46019篇
  1981年   43119篇
  1980年   40505篇
  1979年   53104篇
  1978年   44035篇
  1977年   38886篇
  1976年   36274篇
  1975年   36276篇
  1974年   39412篇
  1973年   37632篇
  1972年   35247篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
ABSTRACT

The lack of stable housing can impair access and continuity of care for patients living with human immunodeficiency virus (HIV). This study investigated the relationship between housing status assessed at multiple time points and several core HIV-related outcomes within the same group of HIV patients experiencing homelessness. Patients with consistently stable housing (CSH) during the year were compared to patients who lacked CSH (non-CSH group). The study outcomes included HIV viral load (VL), CD4 counts, and health care utilization. Multivariable and propensity weighted analyses were used to assess outcomes adjusting for potential group differences. Of 208 patients, 88 (42%) had CSH and 120 (58%) were non-CSH. Patients with CSH had significantly higher proportion of VL suppression and higher mean CD4 counts. The frequency of nurse visits in the CSH group was less than a half of that in the non-CSH group. Patients with CSH were less likely to be admitted to the medical respite facility, and if admitted, their length of stay was about a half of that for the non-CSH group. Our study findings show that patients with CSH had significantly better HIV virologic control and immune status as well as improved health care utilization.  相似文献   
2.
3.
4.
5.
6.
7.
8.
9.
10.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  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-23

京公网安备 11010802026262号