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   2173篇
  免费   109篇
  国内免费   13篇
耳鼻咽喉   12篇
儿科学   98篇
妇产科学   116篇
基础医学   181篇
口腔科学   46篇
临床医学   246篇
内科学   398篇
皮肤病学   50篇
神经病学   43篇
特种医学   312篇
外科学   231篇
综合类   136篇
预防医学   117篇
眼科学   13篇
药学   169篇
  1篇
中国医学   74篇
肿瘤学   52篇
  2021年   17篇
  2020年   15篇
  2018年   17篇
  2017年   21篇
  2016年   19篇
  2015年   43篇
  2014年   52篇
  2013年   56篇
  2012年   80篇
  2011年   75篇
  2010年   64篇
  2009年   55篇
  2008年   72篇
  2007年   67篇
  2006年   77篇
  2005年   48篇
  2004年   53篇
  2003年   42篇
  2002年   46篇
  2001年   39篇
  2000年   46篇
  1999年   48篇
  1998年   57篇
  1997年   65篇
  1996年   54篇
  1995年   47篇
  1994年   61篇
  1993年   41篇
  1992年   29篇
  1991年   24篇
  1990年   35篇
  1989年   44篇
  1988年   35篇
  1987年   43篇
  1986年   36篇
  1985年   26篇
  1984年   24篇
  1983年   21篇
  1982年   15篇
  1981年   29篇
  1980年   21篇
  1978年   13篇
  1959年   35篇
  1958年   58篇
  1957年   87篇
  1956年   45篇
  1955年   75篇
  1954年   68篇
  1953年   17篇
  1952年   14篇
排序方式: 共有2295条查询结果,搜索用时 19 毫秒
131.
132.
Thymic cysts in mediastinal Hodgkin disease   总被引:3,自引:0,他引:3  
Three cases of proved thymic cysts associated with mediastinal Hodgkin disease are presented. Two illustrate regression of lymphoma with chemotherapy but persistence of thymic cysts. The third case demonstrates a thymic cyst in untreated Hodgkin disease. These cases suggest that such cysts are probably neither coincidental with nor a consequence of therapy but are probably related to initial thymic involvement by Hodgkin disease.  相似文献   
133.
In vivo 1H MRS can be used to detect and quantify the lactate resonance at 1.3 ppm provided that overlapping lipid resonances are eliminated. A homonuclear spectral editing method was developed to acquire uncontaminated 1H spectra of lactate with adiabatic pulses. An advantage of the adiabatic pulse sequence is the ability to induce uniform flip angles and to maximize sensitivity in applications employing surface coil transmitters which produce highly inhomogeneous B1. Glycolytic activity in an intracerebral C6 glioma in rats was monitored by using adiabatic editing sequences to observe [3-13C]lactate produced from infused [1-13C]glucose. Acute hyperglycemia (serum glucose >22 mM, n = 10) had no significant effect (P = 0.08) on the total ([12C]+ [13C]) tumor lactate signal intensity.  相似文献   
134.
135.
136.
137.
Studies on Reproduction in Rats with Meclofenamate Sodium, aNonsteroidal Anti-inflammatory Agent. PETRERE, J. A., HUMPHREY,R. R., ANDERSON, J. A., FITZGERALD, J. E., AND DE LA IGLESIA,F. A. (1985). Fundam. Appl. Toxicol. 5, 665–671. Reproductionand teratology studies were performed in rats given meclofenamatesodium, a nonsteroidal anti-inflammatory agent. Dosages of 0,3, 6, and 9 mg/kg were administered orally as dietary admixturesin the Fertility and Perinatal-Postnatal studies. In the Teratologystudy, dosages of 10, 12, 15, and 20 mg/kg were administeredby intragastric intubation. In the Male-Fertility study no adverseeffects on fertility or litter and offspring parameters wereobserved in two generations. In the Female-Fertility and Perinatal-Postnatalstudies, maternal toxicity (death associated with intestinalulceration and adhesions) was particularly evident during lactation.Prolonged gestation periods, decreased weanling weights, andincreased weanling mortality were evident at dosages of 6 and9 mg/kg. Increased postimplantation loss occurred at 6 and 9mg/kg in the Term Sacrifice subgroup of the Female-Fertilitystudy. Fertility rates were unaffected and all other litterand offspring parameters of the F1 and F2 generations appearednormal. In the Teratology study no adverse effects on embryonicor fetal development were evident at maternally toxic dosagesup to 20 mg/kg. © 1985 Society of Texicology.  相似文献   
138.
139.
140.
Cardiac surgery involving cardiopulmonary bypass (CPB) leads to activation of the hemostatic/inflammatory system. We compared the influence of a half-dose aprotinin regimen on postoperative blood loss and the activation of the hemostatic/inflammatory system during CPB, when used during a heparin-level-based heparin management for cardiac surgery. Two-hundred patients (n = 100 in each group) were enrolled in this randomized prospective study. In Group I only heparin was given according to the results of the Hepcon HMS Plus. In Group II aprotinin was added with a bolus of 1 x 10(6) kallikrein inhibiting units (KIU) for the patient immediately before initiation of CPB, 1 x 10(6) KIU in the priming solution of the CPB, and a continuous infusion of 250,000 KIU/h during CPB. Postoperative blood loss was determined after 12 h. Heparin and antithrombin activity were evaluated by an anti-Xa assay and measurement of antithrombin III activity. Hemostatic activation was evaluated by adenosine diphosphate-stimulated platelet aggregometry and by measurements of the generation/release of beta-thromboglobulin (beta-TG), soluble P-selectin (sPS), thrombin (TAT), prothrombin 1 and 2 fragments (PTF1+2), factor XIIa (FXIIa), plasmin (PAP), and D-dimers. Inflammatory response was evaluated by measuring complement factors 5b-9 (C5b-9), interleukin (IL)-6, and neutrophil elastase (NE). There were no differences in the pre-CPB values or duration of CPB between the two groups. There were no differences in the post-CPB values for platelet count, platelet aggregation, beta-TG, sPS, TAT, PTF1+2, C5b-9, NE, or IL-6. The additional use of aprotinin resulted in a significant decrease of PAP, D-dimers, and 12 h postoperative blood loss, whereas generation of the contact factor XIIa was increased. The administration of aprotinin significantly reduced postoperative blood loss after cardiac surgery and CPB. This most likely has to be attributed to the antifibrinolytic effects of aprotinin. No effects on thrombin generation, platelet activation, inflammatory response, or clinical outcome were noted. IMPLICATIONS: The use of half-dose aprotinin and heparin-level-based anticoagulation management during cardiopulmonary bypass leads to a significant reduction of postoperative blood loss after cardiac surgery. This effect can most likely be attributed to the antifibrinolytic effects of aprotinin, as we did not observe effects on other variables of activation of the hemostatic/inflammatory system.  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