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   1582篇
  免费   147篇
  国内免费   11篇
耳鼻咽喉   13篇
儿科学   114篇
妇产科学   20篇
基础医学   189篇
口腔科学   40篇
临床医学   240篇
内科学   295篇
皮肤病学   28篇
神经病学   36篇
特种医学   327篇
外科学   142篇
综合类   21篇
预防医学   125篇
眼科学   9篇
药学   63篇
肿瘤学   78篇
  2023年   7篇
  2021年   12篇
  2020年   9篇
  2019年   14篇
  2018年   22篇
  2017年   9篇
  2016年   16篇
  2015年   21篇
  2014年   23篇
  2013年   40篇
  2012年   25篇
  2011年   29篇
  2010年   37篇
  2009年   33篇
  2008年   25篇
  2007年   54篇
  2006年   38篇
  2005年   48篇
  2004年   44篇
  2003年   26篇
  2002年   25篇
  2001年   37篇
  2000年   22篇
  1999年   43篇
  1998年   98篇
  1997年   79篇
  1996年   84篇
  1995年   60篇
  1994年   61篇
  1993年   65篇
  1992年   34篇
  1991年   28篇
  1990年   24篇
  1989年   63篇
  1988年   45篇
  1987年   54篇
  1986年   37篇
  1985年   40篇
  1984年   35篇
  1983年   32篇
  1982年   26篇
  1981年   29篇
  1980年   31篇
  1979年   17篇
  1978年   19篇
  1977年   28篇
  1976年   21篇
  1975年   17篇
  1974年   10篇
  1971年   6篇
排序方式: 共有1740条查询结果,搜索用时 15 毫秒
61.
62.
Anal cancer is one of the most common non‐AIDS‐defining malignancies in the era of combination antiretroviral therapy. Its precursor lesion, anal intraepithelial neoplasia (AIN), is highly prevalent in HIV‐infected populations. More than 90% of anal squamous cell cancers are attributable to human papillomavirus (HPV). While the biology of HPV‐related intraepithelial neoplasia is consistent across lower anogenital sites, the natural history of AIN is not well established and cannot be assumed to be identical to that of cervical intraepithelial neoplasia. Screening strategies to prevent anal cancer should be developed based on robust natural history data in HIV‐infected and uninfected populations. Likewise, treatments need to be tested in randomized clinical trials, and reserved for those at significant risk of progression to cancer. This review covers the epidemiology, pathogenesis and immunology of HPV infection, AIN and anal cancer, and summarizes the current diagnosis, screening and treatment strategies in HIV‐infected adults.  相似文献   
63.
64.
Loss of function mutations in FREM1 have been demonstrated in Manitoba‐oculo‐tricho‐anal (MOTA) syndrome and Bifid Nose Renal Agenesis and Anorectal malformations (BNAR) syndrome, but the wider phenotypic spectrum that is associated with FREM1 mutations remains to be defined. We screened three probands with phenotypic features of MOTA syndrome. In one severely affected infant who was diagnosed with MOTA syndrome because of bilateral eyelid colobomas, a bifid nasal tip, hydrometrocolpos and vaginal atresia, we found two nonsense mutations that likely result in complete loss of FREM1 function. This infant also had renal dysplasia, a finding more consistent with BNAR syndrome. Another male who was homozygous for a novel stop mutation had an extensive eyelid colobomas, corneopalpebral synechiae, and unilateral renal agenesis. A third male child diagnosed with MOTA syndrome because of corneopalpebral synechiae and eyelid colobomas had a homozygous splice site mutation in FREM1. These cases illustrate that disruption of the FREM1 gene can produce a spectrum of clinical manifestations encompassing the previously described MOTA and BNAR syndromes, and that features of both syndromes may be seen in the same individual. The phenotype of FREM1‐related disorders is thus more pleiotropic than for MOTA and BNAR syndrome alone and more closely resembles the widespread clinical involvement seen with Fraser syndrome. Moreover, our first case demonstrates that vaginal atresia may be a feature of FREM1‐related disorders. © 2013 Wiley Periodicals, Inc.  相似文献   
65.
66.
The focus on quality of life issues in wound care has justly taken a far greater importance. With the acceptance that pain can be a major factor to the patient, and in particular, pain at dressing change comes the opportunity for avoidance and/or reduction strategies. Whilst pain has been associated with wound infection for millennia, it is only much more recently that this has received due attention from research and clinical practice. In this study, the nature of pain, changes in pain and pain associated with infection are the focal points. A Delphi approach, now a frequently used tool in wound care research, has been used to obtain expert opinion on these aspects of management.  相似文献   
67.
Background: Advantages of cross‐pin retained implant supported restorations (ISRs) include predictable retrieval and predictable retention. Unlike direct to fixture (DTF) or cement retained restorations, the prosthetic design of a cross‐pinned restoration retains gaps at the interfaces between the crown, abutment and cross‐pin screw. These spaces permit leakage into the suprastructure and gasket placement has been recommended to prevent this leakage. Methods: Five different gaskets were assessed for their ability to prevent leakage into a cross‐pinned ISR. The gaskets tested were: cement admixture on the cross‐pin screw; cement admixture on the inner surface of the coping and the cross‐pin screw; cement admixture on the inner surface of the coping only; cement admixture placed 1 mm from the margin of the coping and a filler placed in the abutment chimney. Results: Only gaskets which sealed both the cross‐pin screw interface and the abutment‐crown interface prevented leakage. A filler placed in the abutment chimney prevented leakage into this space but did not prevent fluid accumulating between the coping and abutment. Conservative placement of cement at the margin of the coping failed to prevent leakage. Conclusions: Cement gaskets may effectively prevent leakage into a cross‐pinned ISR. However, the use of a cement as a gasket has to be weighed against the issue of predictable retrieval, cement extrusion and incomplete seating.  相似文献   
68.
69.
70.
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