Serum Amyloid A Receptor Blockade and Incorporation into High-Density Lipoprotein Modulates Its Pro-Inflammatory and Pro-Thrombotic Activities on Vascular Endothelial Cells

The acute phase protein serum amyloid A (SAA), a marker of inflammation, induces expression of pro-inflammatory and pro-thrombotic mediators including ICAM-1, VCAM-1, IL-6, IL-8, MCP-1 and tissue factor (TF) in both monocytes/macrophages and endothelial cells, and induces endothelial dysfunction—a precursor to atherosclerosis. In this study, we determined the effect of pharmacological inhibition of known SAA receptors on pro-inflammatory and pro-thrombotic activities of SAA in human carotid artery endothelial cells (HCtAEC). HCtAEC were pre-treated with inhibitors of formyl peptide receptor-like-1 (FPRL-1), WRW4; receptor for advanced glycation-endproducts (RAGE), (endogenous secretory RAGE; esRAGE) and toll-like receptors-2/4 (TLR2/4) (OxPapC), before stimulation by added SAA. Inhibitor activity was also compared to high-density lipoprotein (HDL), a known inhibitor of SAA-induced effects on endothelial cells. SAA significantly increased gene expression of TF, NFκB and TNF and protein levels of TF and VEGF in HCtAEC. These effects were inhibited to variable extents by WRW4, esRAGE and OxPapC either alone or in combination, suggesting involvement of endothelial cell SAA receptors in pro-atherogenic gene expression. In contrast, HDL consistently showed the greatest inhibitory action, and often abrogated SAA-mediated responses. Increasing HDL levels relative to circulating free SAA may prevent SAA-mediated endothelial dysfunction and ameliorate atherogenesis.     

Effects of mechanical recycling on optical properties and microstructure of recycled high-density polyethylene pellets and bottles

The demand for recycling high-density polyethylene (HDPE) utilizing mechanical recycling technologies is currently felt strongly by both society and industry. However, thermal oxidation of the polymer during the recycling process may lead to irreversible changes in the material properties of recycled high-density polyethylene (rHDPE). The effects of mechanical recycling on the optical characteristics and microstructure of rHDPE pellets and bottles were investigated in this study. The results revealed that the apparent color of the rHDPE became more yellow and gray compared to the virgin HDPE (vHDPE), and showed a signal at 670–680 nm in the solar reflectance spectrum. The thermal oxidation of rHDPE considerably raised the absorption intensities of carbonyl, ester, and hydroxyl groups in attenuated total reflection Fourier transform infrared spectrum. In addition, the presence of carbonyl and hydroxyl unsaturated chemicals might make it challenging to recognize the distinctive peaks of vHDPE in the ultraviolet–visible diffuse reflectance (UV–Vis-DIR) spectra at wavelengths less than 400 nm. Thermal oxidation of rHDPE was also confirmed in the C OH, CO, and O CO valence structures of C1s and O1s. A characteristic valence band (VB) profile at 25 eV can be used as the recognizable information for the oxidation of rHDPE. The microstructure of the surface of rHDPE pellets exhibited rough and uneven morphological defects. The higher recycled content made rHDPE bottles' surface morphology rougher and their cross-section microstructure thinner and more porous than vHDPE bottles.     

Fabrication of fullerene decorated by iron compound and its effect on the thermal stability and flammability for high-density polyethylene

Fullerene decorated by iron compound (C₆₀-Fe) is fabricated via solution reaction and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), wide-angle X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Upon incorporating C₆₀-Fe into high-density polyethylene (HDPE) matrix by melt blending, the thermal and thermo-oxidative stability of HDPE are considerably increased, the oxidative induction time (OIT) is dramatically extend. When the concentration of C₆₀-Fe reached 5 wt%, the onset degradation temperature in air increased from 352°C to 422°C, and the OIT dramatically delayed from 4.5 to 47.8 minutes. Moreover, from microscale combustion calorimetry (MCC), C₆₀-Fe can reduce the peak heat release rate (PHRR), heat release capacity (HRC), and total heat release (THR) values of the composites, all of which are very important parameters for evaluating the fire retardancy of a polymeric material.     

隧道工程质量无损检测的方法组合探讨

本文阐明了采用探地雷达和高密度地震映像的方法组合 ,对隧道质量进行无损检测的方法原理和技术要点。并通过实例说明由此检测隧道的衬砌厚度、设计构件的结构、断层、空隙、脱空及不密实等隐患 ,是行之有效的组合方法。     

界面相容剂对PE-HD/木粉复合材料力学性能的影响

用不同的界面相容剂对高密度聚乙烯(PE-HD)/木粉复合材料进行界面处理,研究了界面相容剂的含量、种类对复合体系力学性能的影响.结果表明,界面相容剂的加入使复合体系的力学性能有不同程度的改善,其中MAPE的加入,对体系的拉伸、弯曲强度提高最大,在MAPE含量为10%时,复合体系的力学性能达到最大值;经EPDM-MA处理的复合材料,其冲击韧性有明显提高;EVA-MA的加入,使复合材料的性能有所提高;SBS对体系界面粘接力的影响不明显;但MAPE和弹性体SBS复配处理的复合体系,其冲击强度的提高尤为显著,这可能是由于MAPE和SBS在复合体系中发生了协效作用,形成具有柔韧性的中间相所致.     

中国石油物探技术现状及发展方向

中国石油经过多年的发展,已形成了一支强大的物探力量,陆上综合实力位居世界前列,形成了8项特色物探技术,其中复杂山地、黄土塬等地震勘探技术处于国际领先水平。在高端技术研发方面,高密度地震、全数字地震、多波等技术在复杂油气藏描述方面初见实效,并建立了较完备的技术流程。中国石油物探技术的自主创新能力显著增强,在软件和装备研发方面,自主研发了物探一体化核心软件,大型地震仪器已通过2 000道野外试生产,在不久的将来将规模生产。为适应新形势下勘探开发需求,中国石油将继续在未来几年技术发展蓝图指导下,开展物探核心装备与软件研制和物探新方法新技术等方面的研究,以迎接"四大工程"对物探技术提出的挑战。图8参10     

高密度电阻法在矿山尾矿坝稳定性分析中的应用研究

介绍了高密度电阻法的特点, 并将该法应用于江西某尾矿坝稳定性测试, 根据测试结果对坝体维稳提出了措施与建议。实践证明, 高密度电阻法是一种高效的坝体稳定性测试方法。     

废旧PE-HD/OMMT纳米复合材料热氧老化性能和燃烧性能研究

以废旧高密度聚乙烯（PE-HD）和蒙脱土（MMT）为原料,采用熔融插层法制备纳米复合材料,考查制备工艺对该材料热氧老化性能和燃烧性能的影响。结果表明,PE-HD复合MMT或有机蒙脱土（OMMT）后,抗热氧老化性能显著降低,阻燃性能增强;十六烷基三甲基溴化铵（CTAB）、OMMT、马来酸酐（MAH）和过氧化二异丙苯（DCP）加入量分别增加时,PE-HD/OMMT纳米复合材料的抗热氧老化性能无显著变化,阻燃性能呈现先增强后降低或稳定的趋势;当CTAB加入量为1 %、OMMT加入量为3 %、MAH和DCP加入量为1.5 %时,PE-HD/OMMT纳米复合材料的极限氧指数达到19.4 %,阻燃性能最好。     

玄武岩残积土综合原位测试与分析研究

受风化环境和成因的影响,未经水平运移的残积土结构性较强,扰动取样后的室内试验无法真实反映残积土的力学性能。在贵州玄武岩地区进行了原位旁压试验、动力触探和高密度电法试验,分析得到了残积土的原位力学参数的空间分布特征。试验结果表明:水平旁压模量EH与竖直旁压模量EV差值在15%左右,两方向的旁压模量相关性较好;该残积土边坡不同位置同一深度处力学参数差别较大;旁压试验所推算的旁压模量Em及地基承载力fk等参数在垂向上均随深度增加逐渐增大;通过高密度电法与旁压试验的对比,可在一定程度上了解残积土边坡力学参数的空间分布;将动力触探击数与旁压试验推算的地基承载力作对比,得出了该地区动力触探击数推算地基承载力的经验公式。