Evaluation of Antioxidant,Antidiabetic and Anticholinesterase Activities of Smallanthus sonchifolius Landraces and Correlation with Their Phytochemical Profiles

The present study aimed to investigate the phytochemical profile of leaf methanol extracts of fourteen Smallanthus sonchifolius (yacon) landraces and their antioxidant, anticholinesterase and antidiabetic activities that could lead to the finding of more effective agents for the treatment and management of Alzheimer’s disease and diabetes. For this purpose, antioxidant activity was assessed using different tests: ferric reducing ability power (FRAP), 2,2-diphenyl-1-picryl hydrazyl (DPPH), nitric oxide (˙NO) and superoxide (O₂˙⁻) scavenging and lipid peroxidation inhibition assays. Anticholinesterase activity was investigated by quantifying the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, whereas antidiabetic activity was investigated by α-amylase and α-glucosidase inhibition tests. To understand the contribution of metabolites, phytochemical screening was also performed by high performance liquid chromatography-diode array detector (HPLC-DAD) system. Among all, methanol extract of PER09, PER04 and ECU44 landraces exhibited the highest relative antioxidant capacity index (RACI). ECU44 was found to be rich in 4,5-di-O-caffeoylquinic acid (CQA) and 3,5-di-O-CQA and displayed a good α-amylase and α-glucosidase inhibition, showing the lowest IC₅₀ values. Flavonoids, instead, seem to be involved in the AChE and BChE inhibition. The results of this study revealed that the bioactive compound content differences could be determinant for the medicinal properties of this plant especially for antioxidant and antidiabetic activities.     

Docosahexaenoic Acid Levels in Blood and Metabolic Syndrome in Obese Children: Is There a Link?

Prevalence of metabolic syndrome is increasing in the pediatric population. Considering the different existing criteria to define metabolic syndrome, the use of the International Diabetes Federation (IDF) criteria has been suggested in children. Docosahexaenoic acid (DHA) has been associated with beneficial effects on health. The evidence about the relationship of DHA status in blood and components of the metabolic syndrome is unclear. This review discusses the possible association between DHA content in plasma and erythrocytes and components of the metabolic syndrome included in the IDF criteria (obesity, alteration of glucose metabolism, blood lipid profile, and blood pressure) and non-alcoholic fatty liver disease in obese children. The current evidence is inconsistent and no definitive conclusion can be drawn in the pediatric population. Well-designed longitudinal and powered trials need to clarify the possible association between blood DHA status and metabolic syndrome.     

铁路罐车流固耦合模型振动特性实验研究

为研究流固耦合运动对铁路罐车振动的影响,以G J70型液碱罐车的1∶5罐车模型进行纵向冲击实验.通过加速度传感器采集罐车在空载、装50％水、装75％水和装95％水4种工况下的罐体的横向加速度、车架的纵向加速度信号及罐体的垂向加速度信号,计算加速度信号的均值与均方根值,利用傅里叶变换对加速度信号进行频谱分析识别振动频率.经过对比分析表明,在流固耦合作用下的铁路罐车振动在各个方向上均产生明显变化,充液工况下具有更多的振动频率,且不同充液比下的振动频率也略有差异.     

浅埋薄基岩采煤工作面上覆岩层纵向贯通裂隙“张开-闭合”规律

浅埋深薄基岩采煤工作面上覆岩层纵向裂隙贯通是形成溃砂溃水通道的主要因素,为掌握该种裂隙“张开-闭合”规律,采用相似模拟、理论分析、现场实测等综合研究方法,深入分析了该种裂隙的张开闭合过程与形式,结果表明：纵向贯通裂隙的张开始于周期来压来临之前,随着工作面的继续推进,该种裂隙随着水平力、岩块错位量的动态变化而逐渐扩展,当扩展至极限时,纵向贯通裂隙随着关键岩块的切落而迅速闭合,伴随着下次周期来压的出现,之后出现该贯通裂隙的进一步压实,以及下一条纵向贯通裂隙的出现。基于上述研究,从工作面推进速度、液压支架支撑力、采空区的充填程度等易于工程控制的3个方面阐述了其对纵向贯通裂隙张开闭合的影响机制,为浅埋薄基岩工作面溃砂溃水隐患控制提供有效依据。     

激光冲击改善W6M05Cr4V2(M2)高速钢刀具材料耐磨性的研究

目的 研究激光冲击强化(LSP)技术对M2高速钢材料表面抗磨损性能的影响.方法 采用高功率短脉冲的强激光束对M2试样进行激光冲击处理,然后用显微硬度计测量试样冲击区横截面上的纵向显微硬度,用磨损试验机对冲击处理前后的试样进行磨损实验.结果 在铝箔涂层、流水约束层作用下对M2高速钢试样进行激光冲击强化处理,试样强化层中的奥氏体晶粒显著细化.试样冲击区横截面上形成了由表及里的纵向显微硬度梯度,获得了深约0.6 mm的硬化层,表层材料显微硬度峰值高达70HRC左右,比基体硬度提高10％左右.激光冲击处理后的M2试样表面较光洁,磨痕较少,磨痕底部相对平滑,犁沟深度较浅,磨损量较小,稳定磨损阶段较长,表面呈现较好的抗咬合性和较高的耐磨性.结论 经激光冲击处理后,M2高速钢材料强化层所获得的较细晶粒和较高硬度有效改善了表面抗磨损性能,进一步提高了M2高速钢刀具的切削性能与使用寿命.     

长石分选及其废水处理现状与发展

概括了长石资源特征及其应用,比较了含钾、钠长石与硅酸盐矿物的晶体结构特点与其可浮性的关系。简述了长石中含铁、钛等金属矿物的影响与去除技术,重点归纳了长石与脉石矿物分离的有氟浮选法、无氟有酸法、无氟无酸法3类分选技术,探讨了长石分选过程中含氟废水与酸性废水的危害和处理技术,展望了长石分选技术的发展方向。     

石英中杂质矿物赋存状态及纯化研究

利用光学显微镜、电子探针、电感耦合等离子发射光谱等测试手段,对江苏某公司块状石英进行了杂质矿物赋存状态及分离纯化研究。结果表明:赋存于石英中杂质元素主要为Al、Na、Ca、Fe、Li、K、Ti;杂质矿物多为原生矿物包裹体,且主要以小于20μm的岩盐和小于120μm的白云母形式赋存于石英晶体界面间。其中Na主要以岩盐形式存在;元素F、Mg、K、Ti、Mn、Fe、Al主要赋存在白云母中,尚有一部分元素Al以类质同象形式取代石英晶格中的元素Si;元素Ca和部分S以氧化物的形式存在;Ba和另一部分S赋存在重晶石中;Cu、Zn共生形成氧化矿。经焙烧,水淬,碱浸出和混合酸浸出,可分离纯化制备出99.991wt%的高纯石英。     

地铁隧道全断面监测数据的建模及断面拟合算法的研究

定期的对地铁隧道进行全断面监测,不仅可以了解盾构管片的真实形状及隧道的稳定性状态,更可以进一步为隧道进行安全评估.该文基于最小二乘法、最小平方中值法、Kalman滤波法提出了一种改进的方法,并通过中位数法剔除孤立点,提高了拟合结果的稳健性.通过高精度的椭圆拟合,能够比较准确地反映隧道变形情况,为运营隧道的形变监测提供直观可靠的数据.     

组合式彩钢复合门窗型材抗弯刚度研究

该文介绍了组合式彩钢复合门窗型材抗弯刚度的试验研究情况。分别给出了型材有50%保证率的标准值(0.5分位值)和有95%保证率的标准值(0.05分位值),得到了不同型材截面的平均极限承载力和平均极限挠度,绘制了每种截面的荷载——挠度曲线,暂时得出跨度对抗弯刚度EI有影响的结论,且跨度越大,抗弯刚度EI越大。     

饱水对岩溶灰岩力学性质与纵波波速的影响

为研究饱水对岩溶灰岩力学性质和纵波波速的影响,进行自然和饱水状态下岩样的力学性能和弹性波测试。试验结果表明:饱水对岩溶灰岩的单轴抗拉强度、抗拉强度和弹性模量有明显的软化作用,饱水状态试样的峰值应变和泊松比整体上大于自然状态的对应值;岩溶灰岩试样在饱水条件下的纵波波速均明显高于自然状态下的纵波波速,试样的单轴抗压强度和抗拉强度与纵波波速具有较高的线性相关性。基于目前的研究现状,阐述了研究成果在隧道与周边高压充填隐伏溶腔间防突岩层稳定性评价及最小防突厚度确定中的应用。