抗氧化剂对Al2O3-C耐火材料增碳作用的影响

以电熔白刚玉和石墨为原料,引入不同的抗氧化剂制备Al2O3-C坩锅,在中频感应炉中研究了含碳耐火材料对超低碳钢钢水的增碳作用。研究结果表明：抗氧化剂的存在可以抑制含碳耐火材料对钢水的增碳作用;在加入相同质量的抗氧化剂时．Al的抑制作用最为明显,Si次之,SiC最差;抗氧化剂对增碳作用的抑制主要原因是抗氧化剂的加入提高了含碳耐火材料的抗钢水渗透和耐侵蚀性能,同时提高了钢水的粘度,降低了碳在钢水中的扩散性能。     

羊栖菜提取物体外自由基清除能力的研究

通过不同溶剂对羊栖菜有效成分进行提取,并采用DPPH(二苯代苦味酰自由基)体系、羟基自由基体系、烷基自由基引发的亚油酸氧化体系、超氧阴离子自由基体系对各提取物的抗氧化性进行研究,并同VE、TBHQ(特丁基对苯二酚)、茶多酚进行了比较,结果得出羊栖菜粗提物只在DPPH体系和烷基自由基引发的亚油酸氧化体系中具有清除作用,其中以0 5%Na2CO3(W/V)为溶剂的提取物抗氧化能力最好,而以DPPH体系作为检测系统最为稳定,效果最佳     

Toxicological effects and risk assessment of lanthanum ions on leaves of Vicia faba L.seedlings

Vicia faba L.seedlings were hydroponically cultivated in 0-12 mg/L of extraneous lanthanum(La) for 15 d to investigate ecotoxicological effects and risk assessment of rare earth elements(REEs).The results showed that reactive oxygen species(ROS) production suchas superoxide radical(O2.-) and hydrogen peroxide(H2O2) were overproduced at higher concentrations of La,resulting in oxidatively modified proteins and shoot growth retardation.While,superoxide dismutase(SOD),catalase(CAT),ascorbate peroxidase(APX) and guaiacolperoxidase(GPX) isoenzymes were elevated to some extent to eliminate excess of ROS.HSP70 production and endopeptidase isoenzymeswere also enhanced,which were involved in repairing or degradation of the oxidatively modified proteins due to La.Thus,the antioxidantisoenzymes,endoprotease isoenzymes and HSP70 worked cooperatively to alleviate the La-induced oxidative damage.The significant enhancement of CAT and APX isoenzymes and HSP70 could also be used as early bioindicators of La-polluted solution.The threshold doserange was firstly delimited as 1-2 mg/L of extraneous La,corresponding to 7.34-9.37 μg/g dry weight in the leaves.These results would behelpful to further understand the toxicological effects and possible mechanisms of REE(s) on crop seedlings.     

明胶酶解液脱色工艺研究

以粉末状活性炭为脱色剂,明胶复合酶解液在不同条件下进行了脱色研究.通过单因素试验和正交试验,确定最佳工艺条件为:活性炭用量为1.5%(w/w),pH为5.5,温度35℃,脱色时间为40 min,胶原蛋白酶解液脱色效果明显,脱色率为86.21%,肽损失率为6.12%.     

丙三醇-水二元溶剂法抗氧化纳米铜的制备

目的基于纳米铜在空气中易被氧化的缺点,制备单分散纳米铜颗粒,并研究改性对其抗氧化性能的影响。方法通过丙三醇-水二元溶剂热法用抗坏血酸还原Cu~(2+)制备纳米铜颗粒。研究丙三醇/水体积比、抗坏血酸用量、聚乙烯吡咯烷酮(PVP)浓度对纳米铜粒径及分散性的影响,并采用柠檬酸和油酸对其进行表面改性处理。结果研究发现,当丙三醇和水的体积比为3∶2,抗坏血酸浓度为0.004mol/L,PVP浓度为0.006 mol/L时,能够得到粒径均一((80±10) nm)且分散性良好的纳米铜。真空环境下保存的纳米铜只有纯铜晶相,但在空气中保存30d后部分被氧化为氧化铜或氧化亚铜。采用柠檬酸改性纳米铜在室温到243℃范围内能保持良好的热稳定性。结论采用丙三醇-水二元溶剂热法制备出了粒径均一、分散性良好的纳米铜。柠檬酸与油酸改性能够显著提高纳米铜的抗氧化与热稳定性能,其改性后在空气中保存30 d仍不被氧化。     

核桃花中绿原酸、新绿原酸和隐绿原酸的提取工艺响应面优化及其抗氧化活性研究

目的 探讨干燥核桃花中绿原酸、隐绿原酸和新绿原酸的最佳提取工艺及其抗氧化活性。方法 采用超声波辅助乙醇法提取核桃花中的绿原酸、新绿原酸和隐绿原酸, 以提取温度、乙醇体积分数、提取时间和料液比为自变量, 以得率的总评归一值(overall desirability, OD)为因变量, 应用响应面对提取工艺进行优化, 并通过体外实验评价了其抗氧化活性。结果 最佳提取工艺为：温度77℃, 乙醇体积分数67%, 提取时间28 min, 料液比1: 23(g/mL)。此时,绿原酸、新绿原酸和隐绿原酸的总提取率最佳, OD值可达0.91, 对DPPH自由基、ABTS自由基和羟自由基的半数抑制浓度(Half-maximal Inhibitory concentrations, IC50)值分别为41.63、41.68和34.43 μg/mL。结论 优选出的工艺稳定可行, 且提取液具有较好的体外抗氧化活性, 为核桃花中绿原酸类成分的进一步开发利用提供了理论基础。     

抗氧剂KY-60的精制研究

KY-60即4,4,-亚甲撑双(2,6-二叔丁基苯酚),是多种合成树脂的优异的抗氧剂,其相容性好,抗氧效能高,挥发性小,对制品无污染,无毒,不着色,对热、氧、龟裂老化有极好的防护作用;尤其是对日光下的橡胶制品老化起了最大的防护效能,对硫化和可塑度均无影响,使用方便,可以与多种辅助抗氧剂、稳定剂配用,具有明显的增效作用。目前国内对KY-60的研究工作已完成了实验室合成,针对KY60生产中产品粒度小、分布不均匀、纯度低、用户使用不便等问题,重结晶作为整个工作的关键一步,为此对KY60结晶过程进行了大量的研究。     

基于三维溶度参数理论研究防老剂4020与橡胶间的相容性

采用三维溶度参数理论并借助计算机软件模拟计算了防老剂4020、天然橡胶(NR)、顺丁橡胶(BR)和丁苯橡胶(SBR)的三维溶度参数值,分别计算了防老剂4020与NR、BR和SBR之间的Flory-Huggins相互作用参数(χ),并与防老剂4020的相容性实验结果进行对比,以预测防老剂与橡胶间的相容性.结果表明,三维溶...     

A Second Life for MAP,a Model Amphipathic Peptide

Cell-penetrating peptides (CPP) have been shown to be efficient in the transport of cargoes into the cells, namely siRNA and DNA, proteins and peptides, and in some cases, small therapeutics. These peptides have emerged as a solution to increase drug concentrations in different tissues and various cell types, therefore having a relevant therapeutic relevance which led to clinical trials. One of them, MAP, is a model amphipathic peptide with an α-helical conformation and both hydrophilic and hydrophobic residues in opposite sides of the helix. It is composed of a mixture of alanines, leucines, and lysines (KLALKLALKALKAALKLA). The CPP MAP has the ability to translocate oligonucleotides, peptides and small proteins. However, taking advantage of its unique properties, in recent years innovative concepts were developed, such as in silico studies of modelling with receptors, coupling and repurposing drugs in the central nervous system and oncology, or involving the construction of dual-drug delivery systems using nanoparticles. In addition to designs of MAP-linked vehicles and strategies to achieve highly effective yet less toxic chemotherapy, this review will be focused on unique molecular structure and how it determines its cellular activity, and also intends to address the most recent and frankly motivating issues for the future.     

米根霉发酵对脱脂薏米麸皮营养组成及抗氧化活性的影响

研究米根霉发酵对脱脂薏米麸皮游离氨基酸、多肽、多酚、黄酮、酚类物质组成及抗氧化活性的影响.结果表明,脱脂薏米麸皮在发酵过程中总游离氨基酸含量逐渐增加,低分子量多肽比例逐渐提高.脱脂薏米麸皮的游离型多酚和黄酮含量在发酵过程中呈逐渐上升的趋势,72 h后分别较发酵前提高了111.7％和168.6％(P＜0.05),而结合型...