简介:摘要:由于金属基体中含有一定量的铬,在基体表面形成致密的Cr2O3氧化膜,即钝化膜。通过阻止阳极区的反应,钝化膜可以增加阳极电位,减缓气体电化学腐蚀,但在一定的腐蚀条件下会发生晶间腐蚀,大大降低材料的硬度、强度、冲击值和断裂韧性,使材料失效。晶间腐蚀能显着减弱晶粒间的结合力,严重时完全失去机械强度。例如,易受这种腐蚀的不锈钢看起来很亮,但在轻冲击时会分解成小颗粒。以晶间腐蚀为起源,应力和介质的共同作用导致晶间应力腐蚀,因此晶间腐蚀有时会成为应力腐蚀的前兆。
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简介:AbstractThe coronavirus disease 2019 (COVID-19) is still causing a wide range of infections and deaths due to the high variability of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, it is necessary to establish a reliable and convenient pseudovirus-based neutralization assay to develop drug targeted variants of SARS-CoV-2. Based on the HIV-1 backbone, we generated a high titer luciferase (Luc)-expressing pseudovirus packaging system. Three dominant S mutant substitution pseudovirus were also established and identified compared to wide type in hACE2-overexpressing HEK-293T cells (293T-ACE2 cells). Compared to serine protease inhibitor camostat mesylate, the cysteine protease inhibitor E-64d could significantly block all SARS-CoV-2 mutant S pseudovirus infection in 293T-ACE2 cells. Furthermore, the neutralization ability of two antibodies targeted receptor-binding domain (RBD) of SARS-CoV-2 spike protein (S) was evaluated, which showed different inhibition dose-effect curves among four types of S pseudovirus. Overall, we developed a pseudovirus-based neutralization assay for SARS-CoV-2, which would be readily adapted to SARS-CoV-2 variants for evaluating antibodies.
简介:AbstractChina has accumulated multiple practices and experiences in building and enhancing malaria surveillance and response system. As China’s engagement into global health has gathered stronger momentum than ever, China together with the Swiss Tropical and Public Health Institute and WHO has organised five sessions of the International Forum on Surveillance-Response System Leading to Tropical Diseases Elimination during 2012-2020, in which malaria elimination has always been one of the hottest topics. In this study, the roles of international network on the surveillance and response system were explored to achieve a global malaria-free goal. China’s approach to malaria elimination has demonstrated significance of global collaboration on taking joint prevention and control, and building a worldwide institutional-based network.
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简介:【摘要】目的:本文通过将常规护理、6s管理模式应用后对比其对患者肾功能指标和安全性的影响,来探讨两种临床措施的实际应用效果。方法:80例样本均来自于2019.6——2021.6之间,均为我院收治的需行透析治疗的年轻患者,随机性的将这80例患者分为两组,并基于不同护理措施,对照组(40例,常规护理)、观察组(40例,6s管理模式)。比较两组应用效果。结果:入组时组间肾功能指标相较P>0.05,经过一段时间护理后,两组指标均有好转,且观察组指标更优,组间相较P<0.05。观察组发生各项不良事件的发生率更低,组间相较P<0.05。结论:6s管理模式在年轻透析患者中的应用价值显著。
简介:摘要:科技创新在各个领域都很重要,特别是在计算机和通信技术领域,也间接影响其他行业。遥感、全球定位系统和地理信息系统能够充分利用科技能力,收集和综合分析各种信息,有利于土地资源的合理利用和土地资源的优化配置,从而促进国家的社会进步和经济发展。土地作为一种不可再生资源,科学利用和有效管理土地对我国来说尤为重要。20世纪80年代,3S技术在土地管理中的应用逐渐扩大,特别是在第二次土地调查后的近两年里,3S技术在定界等领域得到了更广泛的应用,例如土地利用规划、地籍测绘等。但需要指出的是,3S技术广泛应用于其他土地管理领域,是一个开发的新软件。基于此,对3S测绘技术在土地开发整理中的合理运用进行研究,仅供参考。