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   38431篇
  免费   2806篇
  国内免费   122篇
耳鼻咽喉   378篇
儿科学   1037篇
妇产科学   674篇
基础医学   5524篇
口腔科学   648篇
临床医学   4023篇
内科学   8223篇
皮肤病学   780篇
神经病学   3928篇
特种医学   1431篇
外国民族医学   11篇
外科学   5329篇
综合类   436篇
一般理论   30篇
预防医学   3099篇
眼科学   732篇
药学   2679篇
中国医学   93篇
肿瘤学   2304篇
  2023年   311篇
  2022年   506篇
  2021年   982篇
  2020年   679篇
  2019年   902篇
  2018年   1078篇
  2017年   867篇
  2016年   976篇
  2015年   1035篇
  2014年   1411篇
  2013年   1730篇
  2012年   2734篇
  2011年   2832篇
  2010年   1602篇
  2009年   1342篇
  2008年   2187篇
  2007年   2339篇
  2006年   2233篇
  2005年   2017篇
  2004年   1903篇
  2003年   1601篇
  2002年   1493篇
  2001年   615篇
  2000年   614篇
  1999年   561篇
  1998年   341篇
  1997年   256篇
  1996年   254篇
  1995年   227篇
  1994年   191篇
  1993年   147篇
  1992年   319篇
  1991年   298篇
  1990年   306篇
  1989年   245篇
  1988年   245篇
  1987年   274篇
  1986年   285篇
  1985年   268篇
  1984年   224篇
  1983年   175篇
  1982年   124篇
  1979年   236篇
  1978年   162篇
  1977年   138篇
  1976年   121篇
  1974年   128篇
  1973年   138篇
  1972年   120篇
  1971年   121篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
941.
In accordance with the tension-free principles for other hernias, umbilical and epigastric hernia repair should probably be mesh-based. The number of randomized studies is increasing, most of them showing significantly less recurrences with the use of a mesh. Different devices are available and are applicable by several approaches. The objective of this review was to evaluate recent literature for the different types of mesh for umbilical and epigastric hernia repair and recurrences after mesh repair. A multi-database search was conducted to reveal relevant studies since 2001 reporting mesh-based repair of primary umbilical/epigastric hernia and their outcomes in adult patients. A total of 20 studies were included, 15 of them solely involved umbilical hernias, whereas the remaining studies included epigastric hernias as well. A median of 124 patients (range, 17–384) was investigated per study. Three quarters of the included studies had a follow-up of at least 2 years. Six studies described the results of laparoscopic approach, of which one reported a recurrence rate of 2.7 %; in the remaining studies, no recurrences occurred. Two comparative studies reported a lower incidence of complications and postoperative pain after laparoscopic repair compared to open repair. Seventeen studies reported results of open techniques, of which seven studies showed no recurrence. Other studies reported recurrence rates up to 3.1 %. A wide range of complication rates were reported (0–33 %). This collective review showed acceptable recurrence rates for mesh-based umbilical and epigastric hernia repair. A wide range of devices was investigated. A tendency toward more complications after laparoscopic repair was found compared to open repair.  相似文献   
942.
943.
944.
945.

Background

Current surgical robots are controlled by a mechanical master located away from the patient, tracking surgeon’s hands by wire and pulleys or mechanical linkage. Contactless hand tracking for surgical robot control is an attractive alternative, because it can be executed with minimal footprint at the patient’s bedside without impairing sterility, while eliminating current disassociation between surgeon and patient. We compared technical and technologic feasibility of contactless hand tracking to the current clinical standard master controllers.

Methods

A hand-tracking system (Kinect?-based 3Gear), a wire-based mechanical master (Mantis Duo), and a clinical mechanical linkage master (da Vinci) were evaluated for technical parameters with strong clinical relevance: system latency, static noise, robot slave tremor, and controller range. Five experienced surgeons performed a skill comparison study, evaluating the three different master controllers for efficiency and accuracy in peg transfer and pointing tasks.

Results

da Vinci had the lowest latency of 89 ms, followed by Mantis with 374 ms and 3Gear with 576 ms. Mantis and da Vinci produced zero static error. 3Gear produced average static error of 0.49 mm. The tremor of the robot used by the 3Gear and Mantis system had a radius of 1.7 mm compared with 0.5 mm for da Vinci. The three master controllers all had similar range. The surgeons took 1.98 times longer to complete the peg transfer task with the 3Gear system compared with Mantis, and 2.72 times longer with Mantis compared with da Vinci (p value 2.1e?9). For the pointer task, surgeons were most accurate with da Vinci with average error of 0.72 mm compared with Mantis’s 1.61 mm and 3Gear’s 2.41 mm (p value 0.00078).

Conclusions

Contactless hand-tracking technology as a surgical master can execute simple surgical tasks. Whereas traditional master controllers outperformed, given that contactless hand-tracking is a first-generation technology, clinical potential is promising and could become a reality with some technical improvements.  相似文献   
946.
947.
948.
949.
Simon Milling 《Immunology》2020,161(2):81-82
Antibodies that bind complement components were first identified over 30 years ago. Investigations into their functions in animal models motivated clinical studies that have now generated licensed products and a strong pipeline of future therapeutics. Despite this, the mechanisms of action of one of the first effective C5-binding antibodies, BB5.1, were not known. Here, we report a new study that reveals these mechanisms, enabling new approaches for designing C5-binding molecules for therapeutic use.  相似文献   
950.
Signalling lymphocyte activation molecule family member 9 (SLAMF9) is an orphan receptor of the CD2/SLAM family of leucocyte surface proteins. Examination of SLAMF9 expression and function indicates that SLAMF9 promotes inflammation by specialized subsets of antigen-presenting cells. Within healthy liver and circulating mouse peripheral blood mononuclear cells, SLAMF9 is expressed on CD11b+, Ly6C, CD11clow, F4/80low, MHC-II+, CX3CR1+ mononuclear phagocytes as well as plasmacytoid dendritic cells. In addition, SLAMF9 can be found on peritoneal B1 cells and small (F4/80low), but not large (F4/80high), peritoneal macrophages. Upon systemic challenge with Salmonella enterica Typhimurium, Slamf9−/− mice were impaired in their ability to clear the infection from the liver. In humans, SLAMF9 is up-regulated upon differentiation of monocytes into macrophages, and lipopolysaccharide stimulation of PMA-differentiated, SLAMF9 knockdown THP-1 cells showed an essential role of SLAMF9 in production of granulocyte–macrophage colony-stimulating factor, tumour necrosis factor-α, and interleukin-1β. Taken together, these data implicate SLAMF9 in the initiation of inflammation and clearance of bacterial infection.  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