信号转导和转录激活子5信号转导途径对受辐射KG-1细胞周期的调控作用

探讨信号转导和转录激活子５（ＳＴＡＴ５）信号转导途径在受辐射ＫＧ－１细胞中对细胞周期的调控作用。通过转染ＳＴＡＴ５基因的显性负突变体（ＤＮ－ＳＴＡＴ５）阻断ＪＡＫ／ＳＴＡＴ的信号传递后,瞬间转染ｃｙｃｌｉｎＤ１基因及ｃｙｃｌｉｎＢ１基因,观察ｃｙｃｌｉｎＤ１蛋白及ｃｙｃｌｉｎＢ１蛋白对受辐射细胞周期阻滞的影响作用。转染ＤＮ－ＳＴＳＡＴ５基因的受辐射ＫＧ－１细胞即使用粒－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）刺激亦不能跳出Ｇ１期阻滞;瞬间转染ｃｙｃｌｉｎＤ１基因及ｃｙｃｌｉｎＢ１基因分别能促进受辐射细胞跳出Ｇ１期和Ｇ２期阻滞。ＧＭ－ＣＳ所激活的ＪＡＫ／ＳＴＡＴ信号转导途径通过促进周期蛋白ｃｙｃｌｉｎＤ１及ｃｙｃｌｉｎＢ１的表达而对受辐射细胞周期进行调控。     

Improving Homology-Directed Repair in Genome Editing Experiments by Influencing the Cell Cycle

Genome editing is currently widely used in biomedical research; however, the use of this method in the clinic is still limited because of its low efficiency and possible side effects. Moreover, the correction of mutations that cause diseases in humans seems to be extremely important and promising. Numerous attempts to improve the efficiency of homology-directed repair-mediated correction of mutations in mammalian cells have focused on influencing the cell cycle. Homology-directed repair is known to occur only in the late S and G2 phases of the cell cycle, so researchers are looking for safe ways to enrich the cell culture with cells in these phases of the cell cycle. This review surveys the main approaches to influencing the cell cycle in genome editing experiments (predominantly using Cas9), for example, the use of cell cycle synchronizers, mitogens, substances that affect cyclin-dependent kinases, hypothermia, inhibition of p53, etc. Despite the fact that all these approaches have a reversible effect on the cell cycle, it is necessary to use them with caution, since cells during the arrest of the cell cycle can accumulate mutations, which can potentially lead to their malignant transformation.     

4D 打印技术在舰炮武器装备维修保障中的应用

为适应未来信息化作战的需要,优化舰炮武器装备的维修保障工作,探讨4D 打印技术在全寿命周期维 修保障中的应用。将舰炮武器装备的维修保障提前至论证决策阶段,并贯穿全寿命周期,分析4D 打印技术原理, 梳理维修保障的关键问题,以期拓展信息化作战条件下舰炮武器装备的维修保障工作思路。结果表明,4D 打印技术 为相关研制部门和一线作战使用单位提供参考依据。     

Discovery of Five New Ethylene-Forming Enzymes for Clean Production of Ethylene in E. coli

Ethylene is an essential platform chemical with a conjugated double bond, which can produce many secondary chemical products through copolymerisation. At present, ethylene production is mainly from petroleum fractionation and cracking, which are unsustainable in the long term, and harmful to our environment. Therefore, a hot research field is seeking a cleaner method for ethylene production. Based on the model ethylene-forming enzyme (Efe) {"type":"entrez-protein","attrs":{"text":"AAD16440.1","term_id":"4323597","term_text":"AAD16440.1"}}AAD16440.1 (6vp4.1.A) from Pseudomonas syringae pv. phaseolicol, we evaluated five putative Efe protein sequences using the data derived from phylogenetic analyses and the conservation of their catalytic structures. Then, pBAD expression frameworks were constructed, and relevant enzymes were expressed in E. coli BL21. Finally, enzymatic activity in vitro and in vivo was detected to demonstrate their catalytic activity. Our results show that the activity in vitro measured by the conversion of α-ketoglutarate was from 0.21–0.72 μmol ethylene/mg/min, which varied across the temperatures. In cells, the activity of the new Efes was 12.28–147.43 μmol/gDCW/h (DCW, dry cellular weight). Both results prove that all the five putative Efes could produce ethylene.     

The Endolysosomal System: The Acid Test for SARS-CoV-2

This review aims to describe and discuss the different functions of the endolysosomal system, from homeostasis to its vital role during viral infections. We will initially describe endolysosomal system’s main functions, presenting recent data on how its compartments are essential for host defense to explore later how SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) and other coronaviruses subvert these organelles for their benefit. It is clear that to succeed, pathogens’ evolution favored the establishment of ways to avoid, escape, or manipulate lysosomal function. The unavoidable coexistence with such an unfriendly milieu imposed on viruses the establishment of a vast array of strategies to make the most out of the invaded cell’s machinery to produce new viruses and maneuvers to escape the host’s defense system.     

9H级燃气-蒸汽联合循环机组主厂房结构设计方案研究

目的 针对9H级燃气-蒸汽联合循环机组主厂房结构设计方案研究,找出最佳的主厂房布置。 方法 通过结构型式、计算方法及设计参数取值进行优化,对技术、初投资、建设工期及施工组织等方面进行详细论述与分析。 结果 分析结果表明：钢筋混凝土结构与钢结构均为可行的,考虑经济性等诸多因素,推荐采用钢筋混凝土结构,屋面采用钢屋架。 结论 主厂房结构采用钢筋混凝土结构,屋面主承重结构采用钢屋架。     

电力设备全寿命周期成本中故障成本的估算

针对全寿命周期成本中故障成本难预测的问题,根据电力设备累积失效概率符合威布尔(Weibull)模型的特点,运用最小二乘法对Weibull模型参数进行估计,计算出设备的期望寿命,从而建立故障成本估算模型。通过比较分析不可修复设备和可修复设备故障成本的计算方式,针对可修复设备平均寿命的特殊性,引进等劣化理论来揭示可修复设备平均寿命之间的关系,并计算出可修复设备的故障成本。算例验证了该方法的有效性。     

华蟾素注射液对人肝癌HepG-2细胞增殖及周期的影响

Objective: The aim of our study was to investigate the effect of Cinobufacini injection on the proliferation and cell cycle of human hepatoma HepG-2 cells. Methods: Cell proliferation was assessed by MTT assay, cell cycle distributionwas detected by the flow cytometry (FCM). The expression of Cyclin A, CDK2 mRNA levels were examined by RT-PCR.Quantitative colorimetric assay was used to analyze Cyclin NCDK2 activity in HepG-2 cells. Results: Cinobufacini injection significantly inhibited HepG-2 cells proliferation in dose- and time-dependent ways; FCM analysis showed Cinobufacini injection induced cell cycle arrest at S phase; RT-PCR assay showed Cinobufacini injection down-regulated Cyclin A, CDK2expression at mRNA levels; Quantitative colorimetric assay showed Cinobufacini injection deceased Cyclin A/CDK2 activity in HepG-2 cells. Conclusion: Cinobufacini injection can inhibit human hepatoma HepG-2 cells growth, induce cell apoptosis and induce cell cycle arrest at S phase, the mechanism of which might be partly related to the down-regulation of Cyclin A,CDK2 mRNA expression and inhibition of Cyclin A/CDK2 activity.     

浅谈我国绿色建筑几点现状问题及发展策略

通过对我国现阶段绿色建筑建设现状几点问题的审慎、严谨、细致的科学分析,提出符合我国文化背景和社会现状的绿色建筑发展策略,以期促进我国绿色建筑的推广应用。