首页 | 本学科首页   官方微博 | 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   3405225篇
  免费   249529篇
  国内免费   7656篇
耳鼻咽喉   47140篇
儿科学   108968篇
妇产科学   94049篇
基础医学   487716篇
口腔科学   100316篇
临床医学   312814篇
内科学   649994篇
皮肤病学   71800篇
神经病学   274204篇
特种医学   129948篇
外国民族医学   900篇
外科学   508072篇
综合类   79376篇
现状与发展   5篇
一般理论   1338篇
预防医学   269352篇
眼科学   78588篇
药学   256056篇
  12篇
中国医学   7409篇
肿瘤学   184353篇
  2018年   35955篇
  2017年   27685篇
  2016年   30606篇
  2015年   34934篇
  2014年   48183篇
  2013年   74130篇
  2012年   100153篇
  2011年   105741篇
  2010年   62799篇
  2009年   58603篇
  2008年   99405篇
  2007年   105033篇
  2006年   105945篇
  2005年   102670篇
  2004年   99356篇
  2003年   94703篇
  2002年   92237篇
  2001年   156607篇
  2000年   162028篇
  1999年   136785篇
  1998年   37793篇
  1997年   33961篇
  1996年   33428篇
  1995年   32040篇
  1994年   29892篇
  1993年   28173篇
  1992年   109786篇
  1991年   107251篇
  1990年   104510篇
  1989年   100992篇
  1988年   93569篇
  1987年   91610篇
  1986年   87063篇
  1985年   83839篇
  1984年   62230篇
  1983年   53450篇
  1982年   31115篇
  1981年   27605篇
  1979年   58207篇
  1978年   40569篇
  1977年   34379篇
  1976年   32070篇
  1975年   34373篇
  1974年   41787篇
  1973年   40427篇
  1972年   37643篇
  1971年   35481篇
  1970年   33063篇
  1969年   30879篇
  1968年   28733篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
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   
8.
9.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  相似文献   
10.
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