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   1570篇
  免费   210篇
  国内免费   50篇
耳鼻咽喉   10篇
儿科学   100篇
妇产科学   18篇
基础医学   134篇
口腔科学   50篇
临床医学   184篇
内科学   526篇
皮肤病学   33篇
神经病学   67篇
特种医学   195篇
外科学   103篇
综合类   102篇
预防医学   77篇
眼科学   15篇
药学   124篇
中国医学   3篇
肿瘤学   89篇
  2023年   19篇
  2022年   13篇
  2021年   26篇
  2020年   23篇
  2019年   10篇
  2018年   24篇
  2017年   43篇
  2016年   41篇
  2015年   35篇
  2014年   69篇
  2013年   77篇
  2012年   41篇
  2011年   44篇
  2010年   80篇
  2009年   79篇
  2008年   42篇
  2007年   84篇
  2006年   51篇
  2005年   37篇
  2004年   43篇
  2003年   29篇
  2002年   22篇
  2001年   43篇
  2000年   33篇
  1999年   29篇
  1998年   83篇
  1997年   69篇
  1996年   60篇
  1995年   52篇
  1994年   47篇
  1993年   49篇
  1992年   25篇
  1991年   23篇
  1990年   33篇
  1989年   27篇
  1988年   32篇
  1987年   29篇
  1986年   32篇
  1985年   26篇
  1984年   26篇
  1983年   21篇
  1982年   14篇
  1981年   13篇
  1980年   12篇
  1979年   18篇
  1978年   16篇
  1977年   13篇
  1976年   15篇
  1975年   13篇
  1970年   9篇
排序方式: 共有1830条查询结果,搜索用时 15 毫秒
1.
Haaga  JR; Beale  SM 《Radiology》1986,161(3):829-830
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).  相似文献   
2.
Microvascular thrombosis is a prominent feature in cardiac delayed xenograft rejection (DXR). We investigated the impact of warfarin or low-molecular-weight heparin (LMWH) anti-coagulation on xenograft function using a heterotopic pig-to-primate model. Donor hearts were from CD46 transgenic pigs and baboon immunosuppression included tacrolimus, sirolimus, anti-CD20 and TPC, an alpha-galactosyl-polyethylene glycol conjugate. Three groups of animals were studied. Group 1 (n = 9) was treated with warfarin, Group 2 (n = 13) with LMWH and Group 3, received no anti-coagulant drugs. The median duration of xenograft function was 20 days (range 3-62 days), 18 days (range 5-109 days) and 15 days (range 4-53 days) in Groups 1 to 3 respectively. Anti-coagulation achieved the targeted international normalized prothrombin ratio (INR) and anti-factor Xa levels consistent with effective in vivo therapy yet, no significant impact on median xenograft function was observed. At rejection, a similar histology of thrombosis and ischemia was apparent in each group and the levels of fibrin deposition and platelet thrombi in rejected tissue was the same. Anti-coagulation with warfarin or LMWH did not have a significant impact on the onset of DXR and microvascular thrombosis. However, a role for specific anti-coagulant strategies to achieve long-term xenograft function cannot be excluded.  相似文献   
3.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  相似文献   
4.
5.
Changes in height of choroidal melanomas after plaque therapy.   总被引:1,自引:1,他引:0       下载免费PDF全文
Serial ultrasonic measurements of 82 uveal melanomas treated with brachytherapy plaques (cobalt-60 and iodine-125) and followed up for up to 141 months revealed that no two patients had identical patterns of change. The mean absolute change in tumour height after treatment was 1.8 mm at six months, 5.6 mm at 48 months for large tumours, and 0.9 and 1.9 mm for medium sized tumours. Eighty of the 82 patients fell into one of three patterns of response: 57 patients had a decrease in height after treatment (type D), 13 patients had the same height after treatment (type S), and 10 patients had a progressive increase in height (type I). Life table comparison showed no correlation between survival and location of tumour, sex of patient, size of tumour when treated, or laterality. There was a slight correlation between age and survival. Patients older than 60 died more frequently from metastatic melanoma than those under 60 (p = 0.06). Life table analysis showed a significant correlation between tumour regression type and survival. At 48 months the best cumulative probability of survival was in patients with type D (88% alive) compared with those of type I (34% alive, p = 0.0004).  相似文献   
6.
7.
To define the indications for elective neck treatment, the cases of 474 previously untreated patients were reviewed who had locally confined major salivary gland cancers treated between 1939 and 1982. Clinically positive nodes were present in 14% (67 of 474). Overall, clinically occult, pathologically positive nodes occurred in 12% (47 of 407). By univariate analysis, several factors appeared to predict the risk of occult metastases; however, multivariate analysis revealed that only size and grade were significant risk factors. Tumors 4 cm or more in size had a 20% (32 of 164) risk of occult metastases compared with a 4% (nine of 220) risk for smaller tumors (P less than 0.00001). High-grade tumors (regardless of histologic type) had a 49% (29 of 59) risk of occult metastases compared with a 7% (15 of 221) risk for intermediate-grade or low-grade tumors (P less than 0.00001). In view of the low frequency of occult metastases in the entire group, routine elective treatment of the neck is not recommended. High-grade tumors and larger tumors have a high rate of occult neck metastases, and treatment should be considered in this group.  相似文献   
8.
9.
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