BMS Derivatives C7-Linked to β-Cyclodextrin and Hyperbranched Polyglycerol Retain Activity against R5-HIV-1NLAD8 Isolates and Can Be Deemed Potential Microbicides

Amides from indole-3-glyoxylic acid and 4-benzoyl-2-methylpiperazine, which are related to entry inhibitors developed by Bristol-Myers Squibb (BMS), have been synthesized with aliphatic chains located at the C7 position of the indole ring. These spacers contain an azido group suitable for the well-known Cu(I)-catalyzed (3+2)-cycloaddition or an activated triple bond for the nucleophilic addition of thiols under physiological conditions. Reaction with polyols (β-cyclodextrin and hyperbranched polyglycerol) decorated with complementary click partners has afforded polyol-BMS-like conjugates that are not cytotoxic (TZM.bl cells) and retain the activity against R5-HIV-1_NLAD8 isolates. Thus, potential vaginal microbicides based on entry inhibitors, which can be called of 4^th generation, are reported here for the first time.     

Translesion Synthesis or Repair by Specialized DNA Polymerases Limits Excessive Genomic Instability upon Replication Stress

DNA can experience “replication stress”, an important source of genome instability, induced by various external or endogenous impediments that slow down or stall DNA synthesis. While genome instability is largely documented to favor both tumor formation and heterogeneity, as well as drug resistance, conversely, excessive instability appears to suppress tumorigenesis and is associated with improved prognosis. These findings support the view that karyotypic diversity, necessary to adapt to selective pressures, may be limited in tumors so as to reduce the risk of excessive instability. This review aims to highlight the contribution of specialized DNA polymerases in limiting extreme genetic instability by allowing DNA replication to occur even in the presence of DNA damage, to either avoid broken forks or favor their repair after collapse. These mechanisms and their key regulators Rad18 and Polθ not only offer diversity and evolutionary advantage by increasing mutagenic events, but also provide cancer cells with a way to escape anti-cancer therapies that target replication forks.     

Electromagnetic transients in the control system of output parameters of a solar power plant in Tajikistan Central Asia region

At present, as the demand for electricity increases in all sectors, there is an urgent need to introduce alternative renewable energy sources into modern energy systems. Renewable energy sources, which consist of solar (photovoltaic, PV), wind and hydro power, are key alternative sources of “green energy’’ energies, but it can also be used to produce “green” hydrogen. Thanks to scientific and technological progress, the cost of photovoltaic solar radiation converters is constantly decreasing at a high rate, which makes it possible to build solar power plants of sufficiently large capacity. In the coming decades, solar energy will become an incentive for the economic development of countries that have the maximum “solar” resource. The Republic of Tajikistan is one of these countries with a high potential for solar energy.The article presents an analysis of the resources and potential of solar energy in the Republic of Tajikistan. The study of electromagnetic transients in networks with photovoltaic solar power plants is performed. The main equations, simulation model and calculations of transients are presented, taking into account changes in voltage on DC buses. An algorithm for controlling the system of automatic control of output parameters is proposed. The analysis of dynamic and static modes in parallel operation of a solar power plant with the grid is carried out. A block diagram and computer model is constructed in the MATLAB package together with Simulink and Power System Blockset.     

Synthesis and Initial Characterization of a Selective,Pseudo-irreversible Inhibitor of Human Butyrylcholinesterase as PET Tracer

The enzyme butyrylcholinesterase (BChE) represents a promising target for imaging probes to potentially enable early diagnosis of neurodegenerative diseases like Alzheimer's disease (AD) and to monitor disease progression in some forms of cancer. In this study, we present the design, facile synthesis, in vitro and preliminary ex vivo and in vivo evaluation of a morpholine-based, selective inhibitor of human BChE as a positron emission tomography (PET) tracer with a pseudo-irreversible binding mode. We demonstrate a novel protecting group strategy for ¹⁸F radiolabeling of carbamate precursors and show that the inhibitory potency as well as kinetic properties of our unlabeled reference compound were retained in comparison to the parent compound. In particular, the prolonged duration of enzyme inhibition of such a morpholinocarbamate motivated us to design a PET tracer, possibly enabling a precise mapping of BChE distribution.     

我国中空吹塑行业发展现状及“十四五”期间重点产品、工艺和设备发展方向

从原料、中空成型机和吹塑工艺等方面介绍了我国中空吹塑行业发展现状，并对电子化学品专用超洁净桶、高压储氢四型瓶、全电动中空成型机、微发泡中空成型技术和挤吹聚对苯二甲酸乙二醇酯（PET）容器等在“十四五”期间的重点产品、工艺和设备发展方向进行了展望。     

18F-NaF注射液的制备及新西兰兔骨折显像

由外伤或肿瘤骨转移造成的隐匿性骨折和愈合情况的准确诊断对制定合适的治疗方案具有非常重要的意义。为考查¹⁸F-NaF PET显像用于骨折诊断的诊断效能，本研究制备了¹⁸F-NaF注射液，并对其进行了质量控制和稳定性研究，然后建立新西兰兔骨折动物模型，模型建立约2周后进行了¹⁸F-NaF PET显像和⁹⁹Tc^m-亚甲基二磷酸盐（⁹⁹Tc^m-MDP）SPECT显像的自身对照实验，并对显像效果进行了比较。结果表明：¹⁸F-NaF的产量大于37 GBq，各项检验结果均符合质控要求，40 ℃下放置8 h和30 ℃下放置10 h所有检验结果均无明显变化；¹⁸F-NaF PET和⁹⁹Tc^m-MDP SPECT两种显像方式均可见全身骨骼，骨折部位呈明显放射性浓聚，但¹⁸F-NaF给药后30 min即可进行PET显像，骨折部位显示更为清晰，骨折部位与对侧正常骨骼的放射性摄取比（T/NT）明显高于⁹⁹Tc^m-MDP，而⁹⁹Tc^m-MDP需在给药后2 h才能进行SPECT显像。本研究表明¹⁸F-NaF PET对骨折的显像性能优于⁹⁹Tc^m-MDP，可明显提高检查流通量和诊断效能。     

氘重氧水液相催化交换法氢正常化工艺研究

液相催化交换法是有效的氢同位素分离方法之一，传统电解法进行氘重氧水氢正常化安全风险大，生产成本高，为此利用液相催化交换法对含氘重氧水进行除氘实验。结果表明，反应温度在30~70 ℃内，随着温度升高，含氘重氧水除氘过程的总体积传质系数（Kya）值先变大后变小，当温度大于60 ℃后，总体积传质系数Kya值逐渐变小，最优反应温度为60 ℃；气液比（摩尔比）在0.5~3.0之间，随着气液比增加，含氘重氧水除氘过程的Kya值愈大，含氘重氧水除氘效果越好，但过大的气液比会引起气液夹带甚至导致液泛，降低反应效率。实验结果可为开展高氘浓度氘重氧水液相催化交换法氢正常化工艺研究提供依据。     

冲击载荷下TC18钛合金力学性能模拟研究

TC18钛合金在退火状态下的屈服强度非常高,进行动态力学性能测试存在一定困难,可优先考虑采用数值模拟方法对其动态力学性能进行研究,而数值模拟结果的精确性主要取决于合金本构方程的精确性。为了减少数值模拟与实验结果之间的差异,在Johnson-Cook模型的基础上做了调整,利用ABAQUS软件的子程序接口自定义了材料本构子程序UMAT,以代码的形式来扩展ABAQUS程序的功能。通过与ABAQUS/Standard软件分析结果以及实验结果的对比,验证了自定义材料本构子程序UMAT计算结果的精确性与可靠性。该研究可为TC18钛合金的结构设计提供参考。     

第七届世界军人运动会核与辐射风险评估与控制

武汉市涉核单位众多,存在一定的核与辐射事故风险。通过对武汉市举办第七届世界军人运动会可能存在的核与辐射风险因素进行识别及评价,确定可能发生的12类核与辐射事故类型及风险水平,进而有针对性的制定风险防控措施,做到辐射应急管理关口前移,在保证军运会期间核技术利用单位正常生产活动的基础上有效的保障了核与辐射安全。     

基于物联网的智慧林业可持续发展策略研究

随着我国科技的不断进步,在“互联网+”大数据的背景下,林业的智慧化发展是必经之路。虽然我国智慧林业的发展已经取得了一定的突破,但是仍然存在着许多问题。基于此,文章在物联网技术的基础上,对智慧林业的可持续发展策略进行探讨。