Design,Synthesis and Biological Evaluation of Steroidal Glycoconjugates as Potential Antiproliferative Agents

To systematically evaluate the impact of neoglycosylation upon the anticancer activities and selectivity of steroids, four series of neoglycosides of diosgenin, pregnenolone, dehydroepiandrosterone and estrone were designed and synthesized according to the neoglycosylation approach. The structures of all the products were elucidated by NMR analysis, and the stereochemistry of C20-MeON-pregnenolone was confirmed by crystal X-ray diffraction. The compounds′ cytotoxicity on five human cancer cell lines was evaluated using a Cell Counting Kit-8 assay, and structure–activity relationships (SAR) are discussed. 2-deoxy-d -glucoside 5 k displayed the most potent antiproliferative activities against HepG2 cells with an IC₅₀ value of 1.5 μM. Further pharmacological experiments on compound 5 k on HepG2 cells revealed that it could cause morphological changes and cell-cycle arrest at the G0/G1 phase and then induced the apoptosis, which might be associated with the enhanced expression of high-mobility group Box 1 (HMGB1). Taken together, these findings prove that the neoglycosylation of steroids could be a promising strategy for the discovery of potential antiproliferative agents.     

Simulation study on the gasification process of Ningdong coal with iron-based oxygen carrier

Chemical looping gasification (CLG) of Ningdong coal by using Fe₂O₃ as the oxygen carriers (OCs) was studied, and the gasification characteristics were obtained. A computation fluid dynamics (CFD) model based on Eulerian‐-Lagrangian multiphase framework was established, and a numerical simulation the coal chemical looping gasification processes in fuel reactor (FR) was investigated. In addition, the heterogeneous reactions, homogeneous reactions and Fe₂O₃ oxygen carriers' reduction reactions were considered in the gasification process. The characteristics of gas flow and gasification in the FR were analyzed and it was found that the experiment results were consistent with the simulation values. The results show that when the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃ and the water vapor volume flow rate was 2.2 ml·min^-1, the mole fraction of syngas reached a maximum value of the experimental result and simulation value were 71.5% and 70.2%, respectively. When the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃, and the water vapor volume flow was 1.8 ml·min^-1; the gasification efficiency reached the maximum value was 62.2%, and the maximum carbon conversion rate was 84.0%.     

500kV输电线路运行稳定性评价模型研究

针对目前500 kV输电线路运维工作任务分配不合理,导致巡检效率低以及线路大修技改采取"差异化"改造方案如何选择规划的问题,建立一种输电线路多维度评价模型.该模型采用模糊综合评价方法,选择与输电线路巡检与大修技改密切相关的多个指标,通过层次分析法与熵权法确定各指标权重,计算各指标对应评语集的隶属度,最终得出评估结果.通过具体案例分析,该模型符合实际情况,能较好地对500 kV输电线路运行稳定性进行评估.     

Genome-Wide Analysis of the Late Embryogenesis Abundant (LEA) and Abscisic Acid-, Stress-, and Ripening-Induced (ASR) Gene Superfamily from Canavalia rosea and Their Roles in Salinity/Alkaline and Drought Tolerance

Canavalia rosea (bay bean), distributing in coastal areas or islands in tropical and subtropical regions, is an extremophile halophyte with good adaptability to seawater and drought. Late embryogenesis abundant (LEA) proteins typically accumulate in response to various abiotic stresses, including dehydration, salinity, high temperature, and cold, or during the late stage of seed development. Abscisic acid-, stress-, and ripening-induced (ASR) genes are stress and developmentally regulated plant-specific genes. In this study, we reported the first comprehensive survey of the LEA and ASR gene superfamily in C. rosea. A total of 84 CrLEAs and three CrASRs were identified in C. rosea and classified into nine groups. All CrLEAs and CrASRs harbored the conserved motif for their family proteins. Our results revealed that the CrLEA genes were widely distributed in different chromosomes, and all of the CrLEA/CrASR genes showed wide expression features in different tissues in C. rosea plants. Additionally, we introduced 10 genes from different groups into yeast to assess the functions of the CrLEAs/CrASRs. These results contribute to our understanding of LEA/ASR genes from halophytes and provide robust candidate genes for functional investigations in plant species adapted to extreme environments.     

The effect of heat treatment on tensile properties of 2D C/SiC composites

Two-dimensional (2D) carbon fiber reinforced silicon carbide (C/SiC) composites with different initial strength were prepared by chemical vapor infiltration (CVI). After tensile property testing, results exhibited that as the heat-treatment temperature (HTT) increases to 1900°C, the tensile strength and toughness of the low strength specimen (LSS) increased by 110% and 530%, while the high strength specimen (HSS) increased by 5.4% and 550%, respectively. As observed from morphologies, the heat treatment increases the graphitization of the amorphous PyC interphase, which leads to the weakening of interfacial bonding strength (IBS). Meanwhile, the defects arising from heat treatment cause thermal residual stress relaxation. Therefore, the tensile strength and toughness of LSS with relatively high initial IBS increase significantly as HTT increases. For HSS with moderate initial IBS, the heat treatment slightly improves the tensile strength, but significantly improves the toughness. Consequently, the post-heat-treatment tensile properties of 2D C/SiC composites can be regulated by varying HTTs and different initial strength.     

伊索昔康的合成方法研究

研究并合成一种昔康类非甾体抗炎药——4-羟基-2-甲基-N-(5-甲基-3-异噁唑基)-2H-1,2-苯并噻嗪-3-羧酰胺-1,1-二氧化物(伊索昔康).以糖精钠(1)和氯乙酸甲酯为原料,经取代、重排扩环、甲基化反应生成4-羟基-2-甲基-2H-1,2-苯并噻嗪-3-羧酸甲酯1,1-二氧化物(4)中间体,化合物(4)与5-甲基-3-异噁唑胺发生酰胺化反应生成伊索昔康(5).目标产物总收率为64.6％,纯度达100％,其结构由1H-NMR和MS表征.     

BiOI/g-C3N4光催化降解甲基橙研究

以三聚氰胺为前驱物采用热聚合法制备了石墨相氮化碳（g-C₃N₄）,并在其表面原位合成了碘氧化铋（BiOI）,构筑了石墨相氮化碳-碘氧化铋复合材料。采用X射线衍射仪（XRD）、傅里叶变换红外光谱仪（FT-IR）、紫外可见漫反射仪（UV-Vis-DRS）等对催化剂进行了表征。结果表明,当BiOI与g-C₃N₄物质的量比为0.5时,BiOI/g-C₃N₄催化剂具有高分散的BiOI颗粒及适中的禁带宽度,吸附和降解甲基橙性能最佳。回流温度为120 ℃时制备的BiOI/g-C₃N₄催化剂具有适中的粒径、比表面积和表面羟基浓度,吸附和降解甲基橙性能最佳,且该催化剂具有良好的重复使用性能。     

陶瓷纳米颗粒在生物医学中的应用进展

近年来,纳米技术成为科学技术领域最重要与最激动人心的前沿领域之一.随着纳米技术的发展,纳米材料在生产和生活的各方面发挥着越来越重要的作用.陶瓷纳米颗粒作为一类重要的纳米材料,拥有体积效应、介电限域效应、量子尺寸效应和量子隧道效应等,使其在生物医学领域具有广阔的应用前景.本文综述了羟基磷灰石、磷酸钙、氧化铁、氧化锌和氧化铈陶瓷纳米颗粒的特点及其在肿瘤成像与治疗、骨组织工程和安全评价等生物医学领域的应用进展,并对陶瓷纳米颗粒在生物医学中的发展提出了几点建议.     

氢化物发生-原子荧光光谱法测定铬矿中砷

铬矿中砷的测定方法对完善铬矿检测方法和质量评价手段有重要意义。在0.5 g样品中加入2 g过氧化钠,于650 ℃熔融20 min,熔融物经盐酸酸化溶解,以10%盐酸为载流,15 g/L硼氢化钾溶液为还原剂,采用氢化物发生-原子荧光光谱法(HG-AFS)进行测定,建立了铬矿中砷测定的新方法。实验表明,砷质量浓度在0.025～100 μg/L范围内与荧光强度呈线性关系,相关系数为1.000 0,方法检出限为0.05 μg/g,定量限为0.17 μg/g。对产地为南非、土耳其、巴基斯坦等19个国家共2 649个铬矿样品的成分进行统计,发现铬矿主要成分为铬、铁、镁、铝和硅;干扰试验表明,这些样品中的共存元素均不干扰测定。按照实验方法对3个不同砷含量的铬矿样品进行精密度和加标回收试验,结果的相对标准偏差(RSD,n=11)为1.4%～6.0%,回收率为96%~109%。将实验方法应用于与铬矿基体近似的铁矿标准物质中砷的测定,测定值与认定值基本一致。     

西宁特钢连铸机技术改造

对西钢新建生产线五机五流小方坯连铸机改造进行了综述.连铸机优良的装备为整条生产线向品种化、规模化、高效化方向快速发展奠定了基础.