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   1043834篇
  免费   71939篇
  国内免费   2891篇
耳鼻咽喉   14120篇
儿科学   32260篇
妇产科学   28476篇
基础医学   145597篇
口腔科学   27795篇
临床医学   88964篇
内科学   213208篇
皮肤病学   21995篇
神经病学   84849篇
特种医学   42692篇
外国民族医学   349篇
外科学   164823篇
综合类   20822篇
一般理论   345篇
预防医学   75462篇
眼科学   23141篇
药学   73036篇
中国医学   2014篇
肿瘤学   58716篇
  2021年   8942篇
  2019年   9277篇
  2018年   12355篇
  2017年   9709篇
  2016年   10558篇
  2015年   12020篇
  2014年   17063篇
  2013年   25499篇
  2012年   35044篇
  2011年   37335篇
  2010年   22370篇
  2009年   21265篇
  2008年   35013篇
  2007年   37040篇
  2006年   37116篇
  2005年   36632篇
  2004年   34774篇
  2003年   33279篇
  2002年   32523篇
  2001年   43243篇
  2000年   44172篇
  1999年   38143篇
  1998年   11700篇
  1997年   10547篇
  1996年   10255篇
  1995年   9557篇
  1994年   9085篇
  1993年   8490篇
  1992年   29290篇
  1991年   28015篇
  1990年   27288篇
  1989年   26186篇
  1988年   24329篇
  1987年   23928篇
  1986年   23004篇
  1985年   21901篇
  1984年   16620篇
  1983年   14178篇
  1982年   8936篇
  1979年   15162篇
  1978年   10769篇
  1977年   9088篇
  1976年   8603篇
  1975年   9346篇
  1974年   11158篇
  1973年   10585篇
  1972年   10019篇
  1971年   9197篇
  1970年   8854篇
  1969年   8250篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  相似文献   
54.
55.
56.

Cerebellar mutism syndrome (CMS) occurs in one out of four children after posterior fossa tumor surgery, with open questions regarding risk factors, pathophysiology, and prevention strategies. Because of similarities between several cerebellar syndromes, a common pathophysiology with damage to the dentato-thalamo-cortical and dentato-rubro-olivary pathways has been proposed. Hypertrophic olivary degeneration (HOD) is an imaging correlate of cerebellar injury observed for instance in stroke patients. Aim of this study was to investigate whether the occurrence and severity of CMS correlates with the extent of damage to the relevant anatomical structures and whether HOD is a time-dependent postoperative neuroimaging correlate of CMS. We performed a retrospective single center study of CMS patients compared with matched non-CMS controls. CMS occurred in 10 children (13% of the overall cohort) with a median age of 8 years. Dentate nucleus (DN) injury significantly correlated with CMS, and superior cerebellar peduncle (SCP) injury was associated by tendency. HOD was observed as a dynamic neuroimaging phenomenon in the postoperative course and its presence significantly correlated with CMS and DN injury. Children who later developed HOD had an earlier onset and tended to have longer persistence of CMS. These findings can guide surgical measures to protect the DN and SCP during posterior fossa tumor resections and to avoid a high damage burden (i.e., bilateral damage). Development of intraoperative neuromonitoring of the cerebellar efferent pathways as well as improved preoperative risk stratification could help to establish a patient-specific strategy with optimal balance between degree of resection and functional integrity.

  相似文献   
57.
58.
59.
Background  The data visualization literature asserts that the details of the optimal data display must be tailored to the specific task, the background of the user, and the characteristics of the data. The general organizing principle of a concept-oriented display is known to be useful for many tasks and data types. Objectives  In this project, we used general principles of data visualization and a co-design process to produce a clinical display tailored to a specific cognitive task, chosen from the anesthesia domain, but with clear generalizability to other clinical tasks. To support the work of the anesthesia-in-charge (AIC) our task was, for a given day, to depict the acuity level and complexity of each patient in the collection of those that will be operated on the following day. The AIC uses this information to optimally allocate anesthesia staff and providers across operating rooms. Methods  We used a co-design process to collaborate with participants who work in the AIC role. We conducted two in-depth interviews with AICs and engaged them in subsequent input on iterative design solutions. Results  Through a co-design process, we found (1) the need to carefully match the level of detail in the display to the level required by the clinical task, (2) the impedance caused by irrelevant information on the screen such as icons relevant only to other tasks, and (3) the desire for a specific but optional trajectory of increasingly detailed textual summaries. Conclusion  This study reports a real-world clinical informatics development project that engaged users as co-designers. Our process led to the user-preferred design of a single binary flag to identify the subset of patients needing further investigation, and then a trajectory of increasingly detailed, text-based abstractions for each patient that can be displayed when more information is needed.  相似文献   
60.
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