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   594篇
  免费   111篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   14篇
妇产科学   7篇
基础医学   62篇
口腔科学   3篇
临床医学   102篇
内科学   87篇
皮肤病学   12篇
神经病学   14篇
特种医学   122篇
外科学   30篇
综合类   39篇
预防医学   42篇
眼科学   1篇
药学   27篇
中国医学   7篇
肿瘤学   142篇
  2024年   2篇
  2023年   5篇
  2022年   7篇
  2021年   16篇
  2020年   12篇
  2019年   13篇
  2018年   32篇
  2017年   15篇
  2016年   25篇
  2015年   19篇
  2014年   29篇
  2013年   33篇
  2012年   20篇
  2011年   27篇
  2010年   30篇
  2009年   32篇
  2008年   26篇
  2007年   23篇
  2006年   9篇
  2005年   13篇
  2004年   28篇
  2003年   28篇
  2002年   34篇
  2001年   25篇
  2000年   13篇
  1999年   14篇
  1998年   31篇
  1997年   14篇
  1996年   13篇
  1995年   12篇
  1994年   16篇
  1993年   16篇
  1992年   4篇
  1991年   3篇
  1989年   9篇
  1988年   8篇
  1987年   4篇
  1986年   7篇
  1985年   4篇
  1984年   4篇
  1983年   8篇
  1982年   8篇
  1981年   2篇
  1980年   4篇
  1979年   2篇
  1978年   5篇
  1977年   2篇
  1976年   1篇
  1975年   3篇
  1974年   1篇
排序方式: 共有712条查询结果,搜索用时 15 毫秒
11.
目的 探讨螺旋CT肝脏双期扫描及门静脉血管三维重建在小肝癌诊断中临床应用价值。方法 25例直径≤3cm小肝癌行螺旋CT肝脏双期扫描及门静脉血管三维重建。三维重建方法采用最大强度投影(MIP)。结果 (1)CT平扫,18例病灶呈低密度,7例病灶呈等密度。肝动脉期,25例病灶强化呈高密度,强化类型分为均匀一致性,斑点状及环状强化。门静脉期25例病灶均呈低密度。(2)门静脉血管MIP三维重建能较好显示小肝癌病灶与肝内门静脉血管关系,肝内门静脉血管分支于病灶处稀少,部分中断或被轻度推移,肿瘤内无门静脉分支血管。结论 螺旋CT肝脏双期扫描及门静脉血管三维重建是诊断和评价小肝癌的有效方法,提高了小肝癌的检出率及诊断正确率,可较好显示病灶与门静脉的关系,为其外科手术提供导向。  相似文献   
12.
[摘要] 目的 探讨肺癌16层螺旋CT伪彩成像肿瘤红色色彩程度与其Ki-67蛋白表达的关系。方法 25例肺癌行16层螺旋CT增强扫描及肿瘤病灶VR伪彩成像,对每个肿瘤病灶进行免疫组化Ki-67蛋白表达检测。用肿瘤VR伪彩成像红色色彩程度代表肿瘤强化状况,分析肺癌病灶VR伪彩成像红色色彩程度与肿瘤Ki-67蛋白表达关系。结果 VR伪彩成像重度红色色彩肺癌5例,中度红色色彩肺癌8例,轻度红色色彩肺癌9例,无红色色彩肺癌3例。13例重、中度红色色彩肺癌强化增加CT值为26.32±9.17Hu,肿瘤Ki-67蛋白表达阳性率为69.23%。12例轻及无红色色彩肺癌强化增加CT值为10.87±4.257Hu,肿瘤Ki-67蛋白表达阳性率为33.33%。重、中度色彩组与轻或无色彩组肺癌Ki-67蛋白表达比较差异有显著性。结论 肺癌CT伪彩成像红色色彩程度与肿瘤Ki-67蛋白表达有一定相关性,可初步反映其Ki-67表达状况。  相似文献   
13.
The epidemiology of hyperuricaemia and gout in Taiwan aborigines   总被引:4,自引:1,他引:4  
To determine the prevalence of hyperuricaemia, gout and gout-related factors in Central Taiwan Atayal aborigines, 342 subjects over 18 yr old were interviewed and examined. A questionnaire was designed to screen for signs and symptoms of gout and gout-related risk factors. Serum uric acid, triglyceride and creatinine were measured in all subjects. The prevalence of hyperuricaemia was 41.4% and that of gout 11.7% in aborigines. The uric acid level was 7.9+/-1.7 mg/dl in males and 5.7+/-1.5 in females, and differed significantly under age 70 yr (P < 0.001). Significantly increased triglyceride, creatinine and alcoholism was found in gouty patients compared with non-gouty patients. In 40 cases with gout, 54% had tophi and 35% of their first- degree relatives had gout. The high prevalence of hyperuricaemia and gout in Taiwan Atayal aborigines, a significant family predisposition, increased creatinine level and alcoholism suggest multiple factors affecting the hyperuricaemia.   相似文献   
14.
15.
Rezaie  AR; Esmon  CT 《Blood》1994,83(9):2526-2531
Protein C is a vitamin K-dependent plasma serine protease zymogen, which upon activation, functions as an anticoagulant. Protein C activation is catalyzed by a complex of thrombin (T) with thrombomodulin (TM). This activation is Ca(2+)-dependent, but Ca2+ inhibits protein C activation by thrombin alone. In most proteases, specificity is determined primarily by the residues that lie near the scissile bond. In protein C, the P2 position is Pro, whereas in the fibrinogen A chain, P2 is Val. We have expressed a Pro-->Val mutant of protein C (P168V) in mammalian cells. At saturating Ca2+, the P168V and wild-type proteins were activated by the T-TM complex equivalently, but half maximal rates of activation were obtained at 50 mumol/L Ca2+ for wild type and approximately 5 mmol/L Ca2+ for the P168V mutant. In the absence of TM, Ca2+ no longer inhibited the activation of the P168V mutant. These results indicate that Pro168 influences the Ca(2+)- dependent conformational changes in protein C that control activation. Recently, a patient with thrombotic complications has been identified with a Pro168-->Leu substitution. Both the P168V and the P168L mutation lead to impaired secretion caused by retention within the cell.  相似文献   
16.
17.
18.

Background

Reliable indicators that can intraoperatively determine the absence of nodal metastasis are in great demand to avoid unnecessary lymphadenectomy. However, little has been reported about the intraoperative diagnostic performance of sentinel node (SN) biopsy.

Methods

Sentinel node biopsy by subserosal or submucosal injection of indocyanine green (ICG) was performed in 241 patients with American Joint Committee on Cancer tumor, node, metastasis staging system, 7th edition, clinical T1 (n = 190) and T2 (n = 51) gastric cancer by two experienced surgeons. All nodes that stained green (green node, GN), representing SNs, were excised before gastrectomy and were sliced into 2-mm sections for intraoperative histological examinations with hematoxylin and eosin staining. The sliced GNs were also examined simultaneously by imprint cytology.

Results

The GNs were detectable in 240 patients (3.8 ± 2.4 nodes per patient; range 1–17 nodes; median 3 nodes), and the success rate of detection was 99.6 % (240 of 241). Of 240 patients with a successful detection, 29 were found to have lymph node (LN) metastases; 16 were diagnosed with LN metastases in both GNs and non-GNs, 12 in GNs alone, and 1 in non-GNs alone. The false-negative rate based on the SN concept was 3.4 % (1 of 29). However, two patients with cT1 gastric cancer were diagnosed as intraoperative GN negative but were later confirmed as GN positive by histological examinations of paraffin sections. As an intraoperative diagnosis, the false-negative rate was 10.3 % (3 of 29).

Conclusions

Sentinel node biopsy using ICG could be performed intraoperatively within reasonable limits under certain conditions, such as multiplanes for detection, combination use of imprint cytology, and open surgery by experienced surgeons.  相似文献   
19.
20.
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