Recent Advances in The Discovery of N‐Myristoyltransferase Inhibitors

N‐Myristoyltransferase (NMT) is a cytosolic monomeric enzyme present in eukaryotes such as fungi and protozoa, but is not found in prokaryotes. The attachment of a 14‐carbon saturated fatty acid, myristate, from myristoyl‐CoA (14:0 CoA) to the N‐terminal glycine residue in a specific set of cellular proteins is commonly called protein N‐myristoylation. The myristoylation reaction catalyzed by the enzyme myristoyl CoA:NMT is both necessary for the growth of various organisms and conclusive for cellular proliferation. Therefore, NMT has been identified as a novel and promising target for antifungal, antiparasitic, and anticancer agents, and a large number of potent NMT inhibitors with antifungal, antiparasitic, and anticancer activities have been reported. Herein we describe recent advances in the discovery of NMT inhibitors. We introduce not only the functions of NMT, but also some representative natural and synthetic inhibitors, with a focus on their biological activity, selectivity, and structure–activity relationship (SAR) information. In particular, inspiration from NMT inhibitor structures and the future direction of these compounds are highlighted.     

Purification and Characterization of Aporphine Alkaloids from Leaves of Nelumbo nucifera Gaertn and Their Effects on Glucose Consumption in 3T3-L1 Adipocytes

Aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn are substances of great interest because of their important pharmacological activities, particularly anti-diabetic, anti-obesity, anti-hyperlipidemic, anti-oxidant, and anti-HIV’s activities. In order to produce large amounts of pure alkaloid for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Without any initial cleanup steps, four main aporphine alkaloids, including 2-hydroxy-1-methoxyaporphine, pronuciferine, nuciferine and roemerine were successfully purified from the crude extract by HSCCC in one step. The separation was performed with a simple two-phase solvent system composed of n-hexane-ethyl acetate-methanol-acetonitrile-water (5:3:3:2.5:5, v/v/v/v/v). In each operation, 100 mg crude extracts was separated and yielded 6.3 mg of 2-hydroxy-1-methoxyaporphine (95.1% purity), 1.1 mg of pronuciferine (96.8% purity), 8.5 mg of nuciferine (98.9% purity), and 2.7 mg of roemerine (97.4%) respectively. The chemical structure of four aporphine alkaloids are identified by means of electrospray ionization MS (ESI-MS) and nuclear magnetic resonance (NMR) analysis. Moreover, the effects of four separated aporphine alkaloids on insulin-stimulated glucose consumption were examined in 3T3-L1 adipocytes. The results showed that 2-hydroxy-1-methoxyaporphine and pronuciferine increased the glucose consumption significantly as rosiglitazone did.     

Ultrafast synthesis of Au(I)-dodecanethiolate nanotubes for advanced Hg2+ sensor electrodes

In this work, an ultrafast and facile method is developed to synthesize Au(I)-dodecanethiolate nanotubes (Au(I)NTs) with the assistance of glycyl-glycyl-glycine (G-G-G). Transmission electron microscopy (TEM) images reveal that the as-prepared Au(I)NTs can be obtained in a 2-h reaction instead of a previous 24-h reaction and are uniform with a hollow structure and smooth surface by virtue of the G-G-G peptide tubular template. According to structural analysis, a possible preparative mechanism is proposed that the G-G-G peptide could help to curl into tube-like morphology in alkaline situation spontaneously to accelerate the formation of Au(I)NTs. Meanwhile, PVDF-stabilized Au(I)NT-modified glassy carbon electrodes present their promising potential for Hg²⁺ detection.     

I/A Series控制系统在BDO装置中的应用

本文介绍了FOXBORO的I/A Series控制系统的特点,结合宁夏英力特年产200000t BDO项目阐述设计方案及应用情况。该系统运行稳定、性能优良,确保了BDO装置的正常运行。     

微波真空干燥工艺在仙灵骨葆方提取物中的适应性研究

考察了提取物相对密度、真空度、微波功率对干燥曲线的影响及干燥时间对活性成分转移率的影响,并以淫羊藿苷转移率为指标优选了最佳干燥时间,结果优选的浸膏相对密度为1.2、真空度为-0.08 MPa、微波功率为400 W、干燥时间为170 s。同时对优选的微波真空干燥工艺与普通真空干燥工艺进行了比较,结果表明,微波真空干燥较其他干燥方法时间短、耗能低,2种干燥方法的活性成分转移率无明显差异。     

锂电池极片辊压机刚度分析与结构优化

在锂电池极片加工过程中,由于其高能量密度要求与涂覆材料力学性能存在矛盾,故需要根据极片所需压缩比严格控制辊压力的大小,而实际中,轧辊特性使两辊之间窄缝距离的直接测定不容易,因此难以通过物理样机试验的方式直接得到生产过程中辊缝与辊压力之间的关系。针对该问题,简化了辊压过程中的物理量,建立了整机和极片变形的数学模型,利用数学模型间接得到整机辊压力与辊缝变化之间的定量关系。采用仿真驱动设计的方式,基于响应面法和多目标优化算法得到整机的设计优化结果。测试试验表明,简化的数学模型可以数字化地描述辊压机的工作情况,便于指导生产中控制极片的制造工艺参数,同时基于响应面的设计优化提高了辊压机的设计生产效率。     

简述PLC技术在矿山机电控制中的应用

PLC技术是自动化领域的一项尤为重要的控制技术,近几年这项技术也得到了突飞猛进的改进及发展,在矿山机电控制领域该项技术也随之得到了广泛应用,在一定程度上满足了煤矿事业发展的需求。PLC技术的应用不仅使得矿山机电自动化的控制更加顺畅,也使煤矿事业得到了发展。就此介绍了PLC技术以及该技术在矿山机电控制中的应用。     

内压缩转子式油气混输泵输入功率的计算与分析

通过分析内压缩转子式油气混输泵工作原理及其内压缩过程,得出了转子泵输入功率P、附加输入功率Ps及其无内压缩过程泵输入功率Pt的理论计算公式,并且通过实例计算分析得出不同内压缩比λ(分别改变吸入压力p1和排出压力pd)和气液比τ对该新型内压缩转子式油气混输泵P、Ps/P及(Pt-P)/Pt的影响规律。当λ一定时,随着τ的增大,P减小,Ps/P和(Pt-P)/Pt增大;改变λ时,P与λ的关系较复杂,Ps/P始终随着λ的增大而减小,(Pt-P)/Pt随着λ的增大而增大,改变p1时,P变化地更快,而改变pd时,Ps/P变地更快,改变p1和pd对(Pt-P)/Pt的影响不大;当τ趋近于1.0时,即纯气工况条件下,P、Ps/P、(Pt-P)/Pt都会发生突变。     

民用飞机副翼卡阻故障试验技术研究

描述了某型号支线飞机的副翼卡阻角度的选取原则,给出了一种卡阻故障的设置方法,并分析了该设置方法对原有飞控系统造成的影响,最后给出了一个副翼卡阻故障的试验方案。已完成的飞行试验结果表明,该方案操作简单,且安全可靠。