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   3261篇
  免费   345篇
  国内免费   50篇
耳鼻咽喉   27篇
儿科学   144篇
妇产科学   53篇
基础医学   409篇
口腔科学   30篇
临床医学   357篇
内科学   485篇
皮肤病学   74篇
神经病学   190篇
特种医学   184篇
外科学   357篇
综合类   354篇
预防医学   354篇
眼科学   114篇
药学   248篇
  3篇
中国医学   140篇
肿瘤学   133篇
  2023年   18篇
  2022年   61篇
  2021年   67篇
  2020年   52篇
  2019年   44篇
  2018年   59篇
  2017年   64篇
  2016年   50篇
  2015年   66篇
  2014年   90篇
  2013年   159篇
  2012年   201篇
  2011年   175篇
  2010年   129篇
  2009年   149篇
  2008年   194篇
  2007年   185篇
  2006年   152篇
  2005年   149篇
  2004年   129篇
  2003年   146篇
  2002年   105篇
  2001年   102篇
  2000年   102篇
  1999年   86篇
  1998年   41篇
  1997年   26篇
  1996年   24篇
  1995年   32篇
  1994年   28篇
  1993年   23篇
  1992年   51篇
  1991年   48篇
  1990年   55篇
  1989年   55篇
  1988年   53篇
  1987年   46篇
  1986年   34篇
  1985年   37篇
  1984年   17篇
  1983年   30篇
  1981年   15篇
  1980年   16篇
  1979年   23篇
  1978年   14篇
  1977年   14篇
  1975年   15篇
  1974年   21篇
  1973年   13篇
  1972年   21篇
排序方式: 共有3656条查询结果,搜索用时 156 毫秒
1.
目的:探讨建立一种放射治疗全身器官剂量数据库平台的可行性。方法:使用基于深度学习的自动勾画软件DeepViewer?1例食管癌患者的全身CT上勾画全身器官,然后利用基于GPU加速的蒙特卡罗软件ARCHER计算相应的器官剂量分布,最后利用Lyman-Kutcher-Burman(LKB)模型评估放疗患者正常组织并发症概率(NTCP)。结果:针对该病例,成功建立基于DeepViewer?ARCHER和LKB模型的全身器官剂量数据库,发现距离靶区越近的器官剂量越大,其中心脏与靶区间距离最小,剂量为14.11 Gy,但因其模型参数特殊,通过LKB模型计算的NTCP为0.00%;左、右肺的剂量分别为3.19和1.16 Gy,但是NTCP值却很大,分别为2.13%和1.60%。对于距离靶区较远的头颈部器官(视交叉、视神经和眼)和腹部器官(直肠、膀胱和股骨头)剂量分别约为9和2 mGy,并且NTCP均近似为0.00%。结论:研究结果证明通过自动勾画软件DeepViewer?蒙特卡罗软件ARCHER和LKB模型建立全身器官剂量数据库的可行性。  相似文献   
2.
Annals of Surgical Oncology - The role of sentinel lymph node biopsy (SLNB) when ductal carcinoma in situ with microinvasion (DCISM) is identified on core biopsy is unclear. Our aim was to assess...  相似文献   
3.
Irritability is often a problem for patients with Post-Traumatic Stress Disorder (PTSD). We describe two cases that illustrate the use of lithium in the treatment of veterans with PTSD who complained of serious problems with irritability or angry outbursts. These cases are discussed in the context of evidence that lithium may be useful in other patients with disorders of impulse control. The evidence linking disorders of anger and impulse control to a dysregulation in neurotransmitter regulation, particularly in serotonergic pathways, supports a psychopharmacologic approach to treatment. These findings should lead to further study of the role of lithium in the treatment of this symptom complex in patients with PTSD.  相似文献   
4.
Forty chronic heloma durum (HD) were treated by electrodesiccation. The mean age of the subjects was 55 years (range 40–72). Effectiveness of treatment was assessed by measuring pain associated with the corn. The subject's tolerance to pain was determined using a 10 cm visual analogue scale. Six weeks postoperatively the mean pain scores were 72.9% lower (P < 0.01) than preoperative scores. Twelve months postoperatively the mean pain scores were 57.6% lower (P < 0.01) than the preoperative scores. Electrodesiccation was found to be successful in reducing the pain experienced from chronic digital and plantar heloma durum.  相似文献   
5.
6.
【摘要】 目的 :探讨羊水粪染与羊膜腔感染的关系。方法 :选择未临产且胎膜完整的剖宫产产妇 5 6例 ,根据术中所见羊水性状分为羊水清亮组、羊水Ⅰ~II度粪染组和羊水III度粪染组。于剖宫产术中取羊水用双抗体夹心ELISA法测IL 6含量 ,取胎盘胎膜做病理检查以了解有无炎性细胞浸润 ,并记录新生儿Apgar评分 ,观察产妇术后有无产褥感染。结果 :3组羊水中IL 6含量差异无显著性 ,3组胎盘标本病理检查示炎性细胞浸润之差异亦无显著性 ,而羊水粪染组新生儿窒息发生率较清亮组明显增加 (P <0 .0 5 )。结论 :羊水粪染尤其是III度粪染是胎儿窘迫的标志 ,而与羊膜腔感染无明显相关性。  相似文献   
7.
Elevated amounts of platelet-associated serum proteins (PASP) can be detected in idiopathic thrombocytopenic purpura (ITP) and are considered to be of patho-aetiological importance especially in the case of acute ITP, that commonly follows acute febrile illnesses. Using a micro-enzyme-linked immunoassay we examined PASP (IgG, IgM, and C3) in 120 paediatric patients with acute fever caused by viral (n = 45), bacterial (n = 48), or non-detectable agents (n = 27) and compared those values to the levels of PASP of an own paediatric control group (n = 21). Two of the patients presented mild temporary thrombocytopenia without clinical signs in the course of their infectious disease. While having normal platelet counts, the majority of our patients (69.2%) however, showed increased levels of PASP (IgG, IgM, C3; single or combined). Significant differences of PASP levels by discrimination of viral and bacterial diseases could not be demonstrated. Elevated platelet-associated complement was of special interest, because - in the absence of low platelet counts due to platelet-specific antibodies - it must be regarded as an indicator for immune complexes (IC) binding to thrombocyte surface IgG Fc-receptors. Thus we suggest that platelets play a considerable role in the elimination of circulating IC.  相似文献   
8.
Gram negative bacteria precipitate reactive arthritis and may be concerned in the pathogenesis of ankylosing spondylitis and other spondyloarthropathies. Susceptibility to many infectious agents is associated with ABO blood group or secretor state, or both. The distribution of the ABO blood group or secretor state, or both, was therefore determined in 87 patients with ankylosing spondylitis and 32 with other forms of spondyloarthropathy. The prevalence of non-secretors was significantly increased in the total patient group (54/114; 47%) and in the subgroup with ankylosing spondylitis (41/84; 49%) compared with local controls (89/334; 27%) (p less than 0.001). Other subgroups of patients showed a similarly increased prevalence of non-secretion (33-47%). The distribution of ABO blood groups did not differ between patients and controls. The association between non-secretor state and ankylosing spondylitis strengthens the hypothesis that ankylosing spondylitis is a form of reactive arthritis. It also suggests several pathogenic mechanisms which may be relevant to the initial hostparasite interaction in ankylosing spondylitis.  相似文献   
9.
Inactivation of viruses in blood products requires that the method employed display selectivity in its action for viral elements while not affecting the biological entity of interest. Several methods have been developed for the treatment of human plasma or products derived from human plasma. An effective technique for the treatment of the cellular components of blood has been lacking, in part due to the inability to develop agents capable of selectively targeting viral agents in the milieu of cellular material. In this paper, we examine the behavior of a group of viral sensitizers designed to be added to cellular samples and be activated upon exposure to UVA light. Upon activation, these agents are capable of disrupting nucleic acids of the virus in a manner that renders them inactive for proliferation. The selectivity observed in this inactivation is determined by the chemical structure of the sensitizer, which can be varied to increase viral killing capacity while diminishing collateral damage to cellular and protein constituents.  相似文献   
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