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   1907083篇
  免费   142548篇
  国内免费   26213篇
耳鼻咽喉   25532篇
儿科学   52495篇
妇产科学   51152篇
基础医学   268767篇
口腔科学   50973篇
临床医学   177931篇
内科学   364093篇
皮肤病学   36765篇
神经病学   139819篇
特种医学   73389篇
外国民族医学   651篇
外科学   281027篇
综合类   83197篇
现状与发展   78篇
一般理论   371篇
预防医学   126310篇
眼科学   46504篇
药学   155866篇
  336篇
中国医学   21558篇
肿瘤学   119030篇
  2022年   16816篇
  2021年   25509篇
  2020年   17978篇
  2019年   20726篇
  2018年   26383篇
  2017年   21232篇
  2016年   21763篇
  2015年   28647篇
  2014年   37711篇
  2013年   45052篇
  2012年   63564篇
  2011年   69131篇
  2010年   41612篇
  2009年   36652篇
  2008年   58876篇
  2007年   62570篇
  2006年   63175篇
  2005年   61692篇
  2004年   53932篇
  2003年   51905篇
  2002年   49908篇
  2001年   87898篇
  2000年   90886篇
  1999年   78787篇
  1998年   23730篇
  1997年   21653篇
  1996年   20474篇
  1995年   19093篇
  1994年   17509篇
  1993年   15266篇
  1992年   57516篇
  1991年   55391篇
  1990年   54137篇
  1989年   52649篇
  1988年   48505篇
  1987年   47105篇
  1986年   44457篇
  1985年   42062篇
  1984年   30491篇
  1983年   26114篇
  1979年   27759篇
  1978年   18957篇
  1977年   16509篇
  1975年   16701篇
  1974年   19536篇
  1973年   18760篇
  1972年   17981篇
  1971年   16836篇
  1970年   15605篇
  1969年   15106篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
82.
83.
84.
85.
86.
87.
The objective of this study was to investigate short segment decompression of degenerative lumbar scoliosis (DLS) and the efficiency of fusion treatment.After DLS surgery, the patients were retrospectively reviewed using the VAS (visual analog scale) and ODI (Oswestry Disability Index) to assess clinical outcomes. All patients underwent posterior lumbar decompressive laminectomy, pedicle screw internal fixation, and posterolateral bone graft fusion surgery. Radiographic measurements included the scoliotic Cobb angle, the fused Cobb angle, the anterior intervertebral angle (AIA), the sagittal intervertebral angle (SIA), and lumbar lordosis angle. The relationships between these parameters were examined by bivariate Pearson analysis and linear regression analysis.Preoperatively, the Cobb angle at the scoliotic segment was 15.4°, which decreased to 10.2° immediately following surgery (P < 0.05). The AIA significantly increased by the last follow-up (4.4 ± 3.4) compared with pre- and postoperative values (2.5 ± 2.8 and 2.2 ± 2.4, respectively; P < 0.05). However, the scoliotic Cobb angle and the AIA did not correlate with the VAS or ODI scores. At the final follow-up, no patients had pseudoarthrosis or internal instrumentation-related complications.Short fusion surgical treatment results in limited DLS correction, with correction loss over time. The AIA between the upper adjacent segment and proximal fused vertebra continues to increase postoperatively, which does not exacerbate clinical symptoms, as reflected by the low reoperation rates for repairing degeneration at adjacent levels.  相似文献   
88.
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose embryo-related genetic abnormalities for couples who present a high risk of a specific inherited disorder. Because this technology involves embryo selection, the medical, bioethical, and legal implications of the technique have been debated, particularly when it is used to select features that are not related to serious diseases. Although several initiatives have attempted to achieve regulatory harmonization, the diversity of healthcare services available and the presence of cultural differences have hampered attempts to achieve this goal. Thus, in different countries, the provision of PGD and regulatory frameworks reflect the perceptions of scientific groups, legislators, and society regarding this technology. In Brazil, several texts have been analyzed by the National Congress to regulate the use of assisted reproduction technologies. Legislative debates, however, are not conclusive, and limited information has been published on how PGD is specifically regulated. The country requires the development of new regulatory standards to ensure adequate access to this technology and to guarantee its safe practice. This study examined official documents published on PGD regulation in Brazil and demonstrated how little direct oversight of PGD currently exists. It provides relevant information to encourage reflection on a particular regulation model in a Brazilian context, and should serve as part of the basis to enable further reform of the clinical practice of PGD in the country.  相似文献   
89.
90.
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