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   238篇
  免费   11篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   7篇
妇产科学   3篇
基础医学   41篇
口腔科学   3篇
临床医学   18篇
内科学   26篇
皮肤病学   20篇
神经病学   13篇
特种医学   3篇
外科学   23篇
综合类   11篇
预防医学   17篇
眼科学   6篇
药学   45篇
中国医学   2篇
肿瘤学   11篇
  2023年   2篇
  2022年   3篇
  2021年   8篇
  2020年   5篇
  2019年   4篇
  2018年   10篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   9篇
  2013年   12篇
  2012年   37篇
  2011年   26篇
  2010年   14篇
  2009年   7篇
  2008年   7篇
  2007年   11篇
  2006年   21篇
  2005年   9篇
  2004年   4篇
  2003年   6篇
  2002年   6篇
  2001年   3篇
  2000年   4篇
  1999年   3篇
  1995年   1篇
  1994年   1篇
  1992年   6篇
  1991年   2篇
  1990年   1篇
  1986年   2篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1976年   1篇
  1974年   1篇
  1971年   1篇
  1970年   1篇
  1969年   3篇
  1968年   1篇
  1917年   1篇
排序方式: 共有250条查询结果,搜索用时 0 毫秒
231.
Vibrio cholerae is responsible for the cause of severe life-threatening infection known as cholera. The study aimed to analyze the genetic make-up of V. cholerae O139 isolates from India and compare its phylogeny with the global strains. The genome data revealed that all isolates were of same sequence type (ST69) which belongs to seventh pandemic clone, with same virulence gene profile and, antimicrobial resistance gene profile except for two isolates. No known CRISPR repeats were identified in any of these isolates. Three different phages were identified among the isolates. All the isolates were found to harbour int SXT and seventh pandemic-specific gene (VC2346). Results from this study enhance our understanding on the persistence of ST69 V. cholerae O139 over 20 years.  相似文献   
232.
Corrections for room scatter, [kSC (d, H)]RM, as a function of source-to-detector distance, d, and source-to-floor-height, H, and also departure from constant room scatter. ks1, have been computed for rooms of various sizes using Monte Carlo methods for air kerma strength standardization of the Amersham CDCS-J-type 137Cs brachytherapy source. These corrections will also be applicable to any type of 137Cs source that may be considered for standardization. It was found that, depending upon the relative position of the source with respect to the surrounding concrete scattering surfaces (side walls, floor and ceiling) and different set of d values, the assumption of constant room scatter overestimated the air kerma strength, Sk, by between 0.2% and 0.6%.  相似文献   
233.
234.
235.
The effects of the putative gap junction blocker carbenoxolone on smooth muscle syncytial properties and junction potentials were studied in guinea pig vas deferens (GPVD). Treatment with 50 μM carbenoxolone reversibly and significantly increased input resistance (R in) (by 682.5 ± 326.0 %, P < 0.05) and abolished cable potentials within 6–7 mins of incubation, without disturbing resting membrane potential. Carbenoxolone reversibly and significantly increased the amplitude of spontaneous excitatory junction potentials (sEJPs) by 96.9 ± 35.45% (P < 0.05), shifted their amplitude distribution rightwards, and reduced their frequency of occurrence by 58.17 ± 17.7% (P < 0.05), without altering their time courses. Similarly, carbenoxolone increased the amplitude of evoked excitatory junction potentials (eEJPs) by 17.7 ± 5.88% and τ decay by 19.43 ± 8.29% (P < 0.05). Our results indicate that carbenoxolone alters the electrical properties and junctional potentials of the GPVD by a mechanism consistent with a relatively specific block of gap junctions. These results suggest that gap junction mediated cell-to-cell communication may significantly modulate the electrical properties and junctional potentials of the GPVD and consequently the physiological functioning of this tissue.  相似文献   
236.
Illuminance level in the softcopy image viewing room is a very important factor to optimize productivity in radiological diagnosis. In today's radiological environment, the illuminance measurements are normally done during the quality control procedure and performed annually. Although the room is equipped with dimmer switches, radiologists are not able to decide the level of illuminance according to the standards. The aim of this study is to develop a simple real-time illuminance detector system to assist the radiologists in deciding an adequate illuminance level during radiological image viewing. The system indicates illuminance in a very simple visual form by using light emitting diodes. By employing the device in the viewing room, illuminance level can be monitored and adjusted effectively.  相似文献   
237.
Herein, we report a small molecule MCH-R1 antagonist which demonstrates oral efficacy in chronic rodent models. Substituted phenyl biaryl urea derivatives were synthesized and evaluated as MCH-R1 antagonists for the treatment of obesity. The structure-activity relationship studies in this series resulted in identification of urea 1 as a potent and selective MCH-R1 antagonist. Compound 1 exhibited oral efficacy in chronic (28 d) rodent models at 3-30 mpk showing significant reduction in food intake and weight gain relative to controls.  相似文献   
238.
We have examined the protective effect of taurine on the myocardial antioxidant defense system in isoprenaline (isoproterenol)-induced myocardial infarction in rats, an animal model of myocardial infarction in man. Levels of diagnostic marker enzymes in plasma, lipid peroxides and reduced glutathione, and the activity of glutathione-dependent antioxidant enzymes and anti-peroxidative enzymes in the heart tissue were determined. Intraperitoneal administration of taurine significantly prevented the isoprenaline-induced increases in the levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine phosphokinase in the plasma of rats. Taurine exerted an antioxidant effect against isoprenaline-induced myocardial infarction by preventing the accumulation of lipid peroxides and by maintaining the level of reduced glutathione and the activity of glutathione peroxidase, glutathione-S-transferase, catalase and superoxide dismutase at near normality. The results indicated that the cardioprotective potential of taurine was probably due to the increase of the activity of the free radical enzymes, or to a counteraction of free radicals by its antioxidant nature, or to a strengthening of myocardial membrane by its membrane stabilizing property.  相似文献   
239.
PURPOSE: To report a case of Kabuki make-up syndrome (KMS) or Niikawa-Kuroki syndrome with Coats-type retinal telangiectasia, which has not been previously reported. METHODS: Observational case report. CONCLUSIONS: There have been only two reports of retinal pigmentation abnormalities and a single case of bilateral macular deposits in KMS, but this is the first report of a Coats type retinal telangiectasia. This case highlights the importance of thorough posterior segment examination in cases of KMS.  相似文献   
240.
Structure-activity studies on piperidino-piperidine 3 led to the discovery of SCH 351125 (1), a selective CCR5 antagonist with potent activity against RANTES binding (K(i) = 2 nM), which possesses subnanomolar activity in blocking viral entry and has excellent antiviral potency versus a panel of primary HIV-1 viral isolates. Compound 1, which has good oral bioavailability in rats, dogs, and monkeys, is proposed as a potential therapeutic agent for the treatment of HIV-1 and has entered human clinical trials.  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