简介:随着我国经济社会的发展和桥梁科学技术的进步,大跨度钢拱桥得到飞速发展。作为钢拱桥的关键构件,H型刚性吊杆的稳定性对钢拱桥的安全运行发挥着至关重要的作用,因其长细比大、阻尼低的特点,在风荷载作用下易产生大幅振动。风致扭转振动作用下H型刚性吊杆的疲劳问题受众多因素影响,且现有振动控制目标不够精确,疲劳评估方法有待完善。因此,开展H型刚性吊杆的疲劳评估研究并建立优化设计流程具有重要的现实指导意义。
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简介:摘要:因突如其来的疫情,全国各地各级各类学校均采用线上教学的方式进行知识传授。随着时间的推移,特殊的教学方式也由最初的新奇变成了中小学生和家长之间矛盾的导火索,一些家庭教育中存在的问题也逐渐凸显出来。线上学习期间家长与孩子相处的时间远远多于平时,这也使原本不了解孩子学习状态的家长逐渐观察到孩子的不足之处。除此之外在父母对孩子缺乏陪伴的情况下,隔辈教育的教养方式就应运而生。随着科技的发展,若老一辈不能紧跟时代潮流,孩子就有可能会与时代脱节。基于以上情况,通过观察法了解分析这例个案,使线上学习期间家庭中种种矛盾以文本的方式呈现,并在可控范围内提出一些建设性的解决方案。
简介:BackgroundTaxifolin(Tax)isanessentialnaturalantioxidant.MultiplestudieshaveshownthatTaxcanprotectcardiomyocytesfromischemia-reperfusioninjury.However,theunderlyingmechanismisstillunclear.MethodsH9C2cellswererandomlydividedintocontrol,H_2O_2group,Taxpretreatmentgroup(Tax+H_2O_2);Taxeffectgroup.CellactivitywasdetectedbyCCK-8andtheintracellularstructurewasobservedbytransmissionelectronmicroscopy.AutophagywasdeterminebyWesternblottinganalysisofBeclin-1,Bcl-2andPKC.ResultsTaxpretreatmentsignificantlyincreasedanti-apoptoticproteinBcl-2andautophagyproteinBeclin-1.ExpressionofPKCwasinhibitedbyTax.ConclusionsTaxpretreatmentcouldprotectH9C2cellsagainstH_2O_2-induceddamagethroughtheBcl-2andautophagypathways.
简介:AbstractHepatitis D virus (HDV) infection causes the most severe form of viral hepatitis with rapid progression to cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Although discovered > 40 years ago, little attention has been paid to this pathogen from both scientific and public communities. However, effectively combating hepatitis D requires advanced scientific knowledge and joint efforts from multi-stakeholders. In this review, we emphasized the recent advances in HDV virology, epidemiology, clinical feature, treatment, and prevention. We not only highlighted the remaining challenges but also the opportunities that can move the field forward.