简介:英语写作是大学英语教学中的重要教学任务,学生英语写作能力的培养需要从事外语教学的教师认真研究写作教学规律、探索教学方法、重视资源的建设和利用。"1-2-3"教学模式是基于建构主义学习理论、人本主义的学习理论和教育技术理论所形成的包含一系列的教育、教学理念,教育、教学方法和教学组织形式的理论体系。本文探讨了该教学模式在开放教育英语写作课程教学中的应用。
简介:【摘要】上颌第一磨牙根管系统复杂多变,变异较多的是近颊根,双根管的发生率很高,但3根管极其罕见。本文报告1例上颌第一磨牙近颊3根管患牙的根管变异发现及诊疗经过,并结合文献归纳总结上颌第一磨牙根管变异发现及根管口定位方法。
简介:AbstractBackground:Microglia plays an indispensable role in the pathological process of sleep deprivation (SD). Here, the potential role of microglial CX3C-chemokine receptor 1 (CX3CR1) in modulating the cognition decline during SD was evaluated in terms of microglial neuroinflammation and synaptic pruning. In this study, we aimed to investigat whether the interference in the microglial function by the CX3CR1 knockout affects the CNS’s response to SD.Methods:Middle-aged wild-type (WT) C57BL/6 and CX3CR1-/- mice were either subjected to SD or allowed normal sleep (S) for 8 h to mimic the pathophysiological changes of middle-aged people after staying up all night. After which, behavioral and histological tests were used to explore their different changes.Results:CX3CR1 deficiency prevented SD-induced cognitive impairments, unlike WT groups. Compared with the CX3CR1-/- S group, the CX3CR1-/- SD mice reported a markedly decreased microglia and cellular oncogene fos density in the dentate gyrus (DG), decreased expression of pro-inflammatory cytokines, and decreased microglial phagocytosis-related factors, whereas increased levels of anti-inflammatory cytokines in the hippocampus and a significant increase in the density of spines of the DG were also noted.Conclusions:These findings suggest that CX3CR1 deficiency leads to different cerebral behaviors and responses to SD. The inflammation-attenuating activity and the related modification of synaptic pruning are possible mechanism candidates, which indicate CX3CR1 as a candidate therapeutic target for the prevention of the sleep loss-induced cognitive impairments.
简介:BasedontheGrammianandPfaffianderivativeformulae,GrammianandPfaffiansolutionsareobtainedfora(3+1)-dimensionalgeneralizedshallowwaterequationintheHirotabilinearform.Moreover,aPfaffianextensionismadefortheequationbymeansofthePfaffianizationprocedure,theWronski-typeandGramm-typePfaffiansolutionsoftheresultingcoupledsystemarepresented.