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1.
Cell surface and secreted proteins provide essential functions for multicellular life. They enter the endoplasmic reticulum (ER) lumen co-translationally, where they mature and fold into their complex three-dimensional structures. The ER is populated with a host of molecular chaperones, associated co-factors, and enzymes that assist and stabilize folded states. Together, they ensure that nascent proteins mature properly or, if this process fails, target them for degradation. BiP, the ER HSP70 chaperone, interacts with unfolded client proteins in a nucleotide-dependent manner, which is tightly regulated by eight DnaJ-type proteins and two nucleotide exchange factors (NEFs), SIL1 and GRP170. Loss of SIL1′s function is the leading cause of Marinesco-Sjögren syndrome (MSS), an autosomal recessive, multisystem disorder. The development of animal models has provided insights into SIL1′s functions and MSS-associated pathologies. This review provides an in-depth update on the current understanding of the molecular mechanisms underlying SIL1′s NEF activity and its role in maintaining ER homeostasis and normal physiology. A precise understanding of the underlying molecular mechanisms associated with the loss of SIL1 may allow for the development of new pharmacological approaches to treat MSS. 相似文献
2.
为了探明辽河油田地下水环境中CO2对Q235钢和X70管线钢的腐蚀规律,采用动电位极化技术及交流阻抗技术研究了不同CO2浓度对该环境下两种钢腐蚀行为的影响,并利用光学显微镜对试样腐蚀界面进行表征。结果表明:随着CO2浓度的增加,Q235和X70钢的交流阻抗图谱的半径均减小,腐蚀电流密度增大,腐蚀坑数量、深度和面积都增加,腐蚀敏感性增大。在低浓度CO2环境下(CO2含量为10%时),Q235钢的腐蚀敏感性比X70钢更高;而在高浓度CO2环境下(CO2含量为20%、40%、60%时),Q235钢的腐蚀速率反而较小,耐腐蚀性更好。 相似文献
3.
通过拉伸及低温冲击试验、光学显微镜、扫描电镜及X射线衍射仪,对Ti70合金板的组织与力学性能的各向异性进行了研究。结果表明,Ti70合金板热轧及退火后组织未出现明显差异,退火过程中主要以回复为主,但在高密度位错的剪切带上出现了一定数量的再结晶晶粒。退火态Ti70合金板横向屈服强度及低温冲击吸收能量都高于纵向,但抗拉强度低于纵向,表现出了明显的各向异性。退火后Ti70合金板形成了较强的{0002}基面织构,其晶面法向向RD方向(纵向)偏转±30°,向TD(横向)方向偏转±41°。由于基面织构更向RD方向集中,因此造成了Ti70合金板力学性能的各向异性。 相似文献
4.
《武汉理工大学学报》2021,(4):13-19
应对中山西环项目对混凝土预制构件的大量需求,提高强度增长速度可以更好地促进预制构件的生产,使模板周转更快,生产效率得到大大提高。合理掺入早强剂可以有效调控混凝土早期强度,传统早强剂或多或少均对混凝土工作性能及后期强度有一定影响,因此开发C-S-H凝胶早强剂。通过在混凝土拌合前掺入,C-S-H凝胶作为晶核类诱导剂,在水泥水化的初期阶段,因为诱导剂的存在能够降低生成水化产物的成核势垒,从而加速水泥水化速率,进而提高混凝土早期强度。 相似文献
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以山西汾西矿业集团公司贺西矿、两渡矿交流提升机TKD-A电控系统改造为背景,介绍SIEMENS6RA70直流传动装置结合S7-300PLC实现异步电动机动力制动的控制原理之关键参数的设置和软件流程。 相似文献
8.
一般大气环境下混凝土强度经时变化模型 总被引:39,自引:1,他引:39
长期暴露试验和经年建筑物实测是研究混凝土强度经时变化规律的二个主要途径。本文在总结国内外暴露试验和实测结果的基础上,分析了一般大气环境下混凝土强度的经时变化规律,利用统计回归方法提出了混凝土强度平均值和标准差的经时变化数学模型,为进一步研究服役结构抗力变化规律奠定了基础。 相似文献
9.
Khalequzzaman M Kamijima M Sakai K Chowdhury NA Hamajima N Nakajima T 《Indoor air》2007,17(4):297-304
Indoor air concentrations of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), and dust particles were measured for 49 biomass and 46 fossil fuel users in urban slums of Dhaka, Bangladesh. The health impacts of these pollutants were assessed on 65 and 51 children under five years old from families who use biomass and fossil fuel as main source of energy, respectively. Mean concentrations of CO were found to be significantly higher in biomass fuel users (P = 0.010), while geometric mean concentrations of benzene, xylene, toluene, hexane, total VOCs, and NO2 were significantly higher (P < 0.01) in the fossil fuel users. Symptoms such as redness of eyes, itching of skin, nasal discharge, cough, shortness of breath, chest tightness, wheezing, or whistling chest were found to be associated with the choice of biomass fuel, with the odds ratio ranging from 4.0 to 6.3. No significant association of use of biomass fuel with respiratory diseases, eczema, diarrhea, or viral fever was observed after adjustment for potential confounders. These results suggest a significant association between the biomass fuel-using population and respiratory symptoms. These symptoms may not be due to the pollutants only, as some other underlying causes may be present. PRACTICAL IMPLICATIONS: The health of children under five years old in Bangladesh, especially those living in poor socioeconomic conditions, is considered to be worsening because of indoor air pollution. It is commonly suggested that biomass fuel should be replaced by fossil fuel, as pollution levels are believed to be higher with biomass fuel. Our findings, however, suggest that pollution can be higher with fossil fuels, and indicate that a switch in fuel from biomass to fossil does not necessarily improve the children's health. Awareness programs should therefore be undertaken to avoid the unnecessary use of gas. Clean fuels and clean stoves should also be ensured to reduce emissions of indoor air pollutants. 相似文献
10.
结合青藏铁路施工实际,分析了多年冻土环境,提出了具体保护设施和措施,并阐述了保护植被,动物,水土的观点,促进了环境保护的贯标工作。 相似文献