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   179篇
  免费   8篇
  国内免费   104篇
儿科学   5篇
妇产科学   1篇
基础医学   14篇
临床医学   73篇
内科学   37篇
皮肤病学   8篇
神经病学   3篇
特种医学   29篇
外科学   14篇
综合类   24篇
预防医学   4篇
眼科学   3篇
药学   62篇
肿瘤学   14篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2018年   3篇
  2017年   1篇
  2016年   1篇
  2015年   3篇
  2014年   1篇
  2013年   9篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2009年   8篇
  2008年   5篇
  2007年   67篇
  2006年   7篇
  2005年   23篇
  2004年   2篇
  2003年   3篇
  2002年   6篇
  2001年   9篇
  2000年   9篇
  1999年   7篇
  1998年   13篇
  1997年   23篇
  1996年   12篇
  1995年   8篇
  1994年   6篇
  1993年   7篇
  1992年   6篇
  1991年   4篇
  1990年   5篇
  1989年   13篇
  1988年   7篇
  1987年   4篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
排序方式: 共有291条查询结果,搜索用时 15 毫秒
71.
72.
自身免疫重叠综合征   总被引:3,自引:0,他引:3  
  相似文献   
73.
74.
Summary Objective. To test a new hypothesis that the glue/contrast admixture used for embolisation reduces the dose delivered to AVMs using an experimental model. Method. A model was created using a block of “solid water” (6 × 5 × 2 cm) with twelve wells of different depths. Different concentrations of the glue admixture (Embucrilate + Lipiodol) were used. The model was irradiated using a 5MV beam with a clinical LINAC system and the dose was checked upstream and downstream. Dose was measured using Kodak XV film, a Vidar 16 bit film scanner and software for therapeutic film dosimetry measurements (RIT software). Results. The radiation dose varied with the distance beyond the glue solid water interface. For distances of 0, 2 and 5 mm to the film, the mean reduction was 13.65% (SD = 2.94), 6.87% (SD = 1.95) and 1.75% (SD = 1.14), respectively. There was also correlation with the Lipiodol concentration in the mixture. The maximum reductions for 80, 50 and 20% Lipiodol concentrations were 16.1% (SD = 1.32), 14.85% (SD = 0.98) and 10% (SD = 1.21), respectively. There was no correlation between the glue depth and the dose delivered. Conclusion. The hypothesis that the glue mixture used for embolisation reduces the radiation dose delivered was experimentally confirmed with this study. Correspondence: Michael L. Schwartz, Sunnybrook Health Sciences Centre, Division of Neurosurgery – Suite A1 29, 2075 Bayview Avenue, Toronto, ON, M4N 3M5 Canada.  相似文献   
75.
76.
苦绳的甾体成分   总被引:3,自引:0,他引:3  
从苦绳(Dregea sinensis Hemsl.)中分离到两个新化合物∶苦绳甙元乙(dresigeninB,1)和苦绳甙I(dresiosideI,2)。经光谱和化学反应确定其结构为∶20-O-(2-甲基丁酰基) 托曼托甙元[20-O-(2-methylbutyryl)-tomentogenin]和二氢肉珊瑚甙元3-O-β-D-吡喃黄夹糖基(1-4)-β-D-吡喃夹竹桃糖基(1-4)-β-D-吡喃磁麻糖甙[dihydrosarcostin 3-O-β-D-thevetopyranosyl(1-4)-β-D-oleandropyranosyl(1-4)-β-D-cymaropyranoside]。  相似文献   
77.
犬冠状动脉定量狭窄造成急性心肌缺血,观察巴曲酶(batroxobin)对冠脉循环及血流动力学的影响。结果显示,batroxobin可剂量依赖性地增加缺血心脏冠脉血流量,2BU·kg-1(0.1BU·kg-1·min-1)iv后40min,缺血犬冠脉流量比盐水对照组增加12%,此时小冠脉阻力由4.1±0.5降至3.2±0.5mmHg·min·ml-1,而大冠脉阻力无明显变化;给药后120min,上述作用仍然持续,且冠脉总阻力降低13%,左室压上升及下降最大速率与盐水对照组相比分别增大14%和16%。结果表明,batroXobin在冠脉低灌流状态下仍可降低小冠脉阻力,增加冠脉流量,这可能是其改善缺血犬冠状循环及心脏功能的机理之一。  相似文献   
78.
We retrospectively reviewed the chart records at the Veterans General Hospital-Taipei for the period between January 1985 and December 1994 to examine the temporal relationship between cancers of the lung and upper aerodigestive tract. A total of 56 patients (54 males, 2 females) with histocytologically proven double primary cancers, with either lung cancer or upper aerodigestive tract cancers appearing first, were found. Squamous cell carcinoma was the most frequent histologic type of lung cancer (squamous 57%, adenocarcinoma 27%, poorly differentiated carcinoma 9%, small cell lung cancer 7%). The incidence of lung cancer patients with upper aerodigestive tract cancer was 0.9% (56/6412). There was no significant difference in the occurrence of upper aerodigestive tract cancer between non-small cell and small cell lung cancer (P > 0.05). However, the incidence of squamous cell lung cancer with upper aerodigestive tract cancer was higher than that of non-squamous cell lung cancer (P < 0.05). With regard to the location of lung cancer, the right lung was more commonly affected than the left (P < 0.001). The locations of upper aerodigestive tract cancers in these lung cancer patients were as follows: larynx 24, nasopharynx 11, esophagus 10, hypopharynx 4, pharyngeal tonsils 2, oral cavity 5. Most upper aerodigestive tract cancers were diagnosed before lung cancer (36/56, 64%), and lung cancer was diagnosed within 3 years in more than half of cases after the diagnosis of upper aerodigestive tract cancer (58.3%). Most lung cancers that preceded upper aerodigestive tract cancer were at an early stage at diagnosis (stage I 4, stage Illa 1), whereas the others, appearing either synchronously or after the diagnosis of upper aerodigestive tract cancer, were mostly at the late stage. There was no difference in survival between lung cancer patients with upper aerodigestive tract cancer and those without (P > 0.05).   相似文献   
79.
Summary The vascular supply to the distal part of sartorius m. was studied in 37 limbs by dissection under magnification and after black ink and latex injections. The muscle or myocutaneous island flap pedicled on the saphenous artery (SA) is supplied by a retrograde circulation through anastomoses of the SA with the perforating branches of the posterior tibial artery and the medial inferior genicular artery. Three different vascular patterns were defined. Retrograde injection also showed good perfusion of the SA. The flap is useful for covering around the knee, the proximal and middle thirds of the lower leg, and the end of the amputation stump. Raising of the flap has not resulted in any functional or cosmetic defect. Eighteen operations have so far been performed, six using the muscle island flap and twelve using the myocutaneous island flap, and all survived completely.
Le lambeaux en îlot myo-cutané du muscle sartorius
Résumé L'apport artériel pour la partie distale du m. sartorius a été étudié sur 37 membres par dissection sous grossissement et après injection d'encre de Chine et de latex. Le lambeau en îlot, musculaire ou myo-cutané, pédiculé sur l'artère saphène (SA), est vascularisé par une circulation rétrograde à travers les anastomoses de la SA avec les branches perforantes de l'artère tibiale postérieure et l'artère inféro-médiale du genou. Trois schémas vasculaires différents ont été définis. L'injection rétrograde montrait aussi une bonne perfusion de la SA. Le lambeau est utile pour la couverture des régions proches du genou, des tiers proximal et moyen de la jambe et de l'extrémité des moignons d'amputation. La réalisation du lambeau n'a entraîné aucun dommage fonctionnel ou cosmétique. Dix-huit interventions ont été réalisées jusqu'ici, six utilisant le lambeau en îlot musculaire et douze utilisant le lambeau en îlot myocutané, sans aucune complication locale.
  相似文献   
80.
As the incidence of atopic conditions continues to increase, emphasis has been placed on understanding the origin of allergy with hope that prevention measures can be achieved. The perinatal environment is important for this understanding, given that both the immune system and microbiome start forming prenatally. Maternal exposure can greatly impact on fetal health. Additionally, the dysfunctional epithelial barrier is influential in allowing allergens and irritants to penetrate the skin or mucosa, leading to the release of proinflammatory cytokines and mediators to drive type 2 tissue inflammation and the onset of allergy. There are numerous factors related to skin, airway, and gut epithelial barriers dysfunction, and genetic predispositions are also present. Comprehensive birth cohort studies and further mechanistic studies will be keys to understanding the origin of allergy.  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