Impact of Scaffold Micro and Macro Architecture on Schwann Cell Proliferation under Dynamic Conditions in a Rotating Wall Vessel Bioreactor

Over the last decade tissue engineering has emerged as a powerful alternative to regenerate lost tissues owing to trauma or tumor. Evidence shows that Schwann cell containing scaffolds have improved performance in vivo as compared to scaffolds that depend on cellularization post implantation. However, owing to limited supply of cells from the patients themselves, several approaches have been taken to enhance cell proliferation rates to produce complete and uniform cellularization of scaffolds. The most common approach is the application of a bioreactor to enhance cell proliferation rate and therefore reduce the time needed to obtain sufficiently significant number of glial cells, prior to implantation.In this study, we show the application of a rotating wall bioreactor system for studying Schwann cell proliferation on nanofibrous spiral shaped scaffolds, prepared by solvent casting and salt leaching techniques. The scaffolds were fabricated from polycaprolactone (PCL), which has ideal mechanical properties and upon degradation does not produce acidic byproducts. The spiral scaffolds were coated with aligned or random nanofibers, produced by electrospinning, to provide a substrate that mimics the native extracellular matrix and the essential contact guidance cues.At the 4 day time point, an enhanced rate of cell proliferation was observed on the open structured nanofibrous spiral scaffolds in a rotating wall bioreactor, as compared to static culture conditions. However, the cell proliferation rate on the other contemporary scaffolds architectures such as the tubular and cylindrical scaffolds show reduced cell proliferation in the bioreactor as compared to static conditions, at the same time point. Moreover, the rotating wall bioreactor does not alter the orientation or the phenotype of the Schwann cells on the aligned nanofiber containing scaffolds, wherein, the cells remain aligned along the length of the scaffolds. Therefore, these open structured spiral scaffolds pre-cultured with Schwann cells, in bioreactors could potentially shorten the time needed for grafts for peripheral nerve regeneration.     

彩色耐热混凝土的试验研究

从原材料选择、配合比设计、颜料的品种及掺量、外加剂等方面对彩色耐热混凝土的耐热性、强度进行了系统的试验研究,得出满足设计强度等级C35、耐热温度500℃、色泽鲜亮的彩色混凝土最佳配合比.通过对混凝土耐热机理的分析.提出骨料性质、颜料掺量对混凝土耐热强度的综合影响是关键因素.     

Degradation behaviour of methamidophos and chlorpyrifos in apple juice treated with pulsed electric fields

Apple juice (13 °Brix) spiked with methamidophos and chlorpyrifos (2–3 mg/l of each compound) was treated by pulsed electric fields (PEF), and pesticide residues were quantified by gas chromatography with flame photometric detection (GC-FPD). Results showed that electric field strength (8–20 kV/cm) and pulse number (6–26 pulses) have significant effects on the degradation of methamidophos and chlorpyrifos. PEF treatment is effective for the degradation of methamidophos and chlorpyrifos residues in apple juice, and chlorpyrifos is much more labile to PEF than methamidophos. An increase in either pulse number or electric field strength could speed the degradation of methamidophos and chlorpyrifos, and the kinetics equations and related parameters quantitatively characterized the degradation behavior of the pesticides. The exponential model better fits the experimental data for all treatments than the linear model.     

MSS62．5移动模架分块浇筑大跨径箱梁桥的施工创新

针对80 m跨径等高连续箱梁的特点,提出了采用已有MSS62.5 m移动模架进行分块浇筑80 m跨径等高连续箱梁的创新思路、施工工艺及步骤,并进行了80 m跨径等高连续箱梁施工工法的概念设计及配筋估算,结果表明所提出的工法技术可行,施工经济,现行的MSS62.5 m移动模架施工跨径可推广至80 m跨径的等高混凝土连续箱梁的施工,且模架的主梁结构几乎不需多大的改造.     

针织毛绒复合地毯生产工艺

针织毛绒复合地毯属地毯类块毯型产品.介绍了针织毛绒复合地毯的产品规格、结构和生产工艺流程,为满足产品质量要求,通过生产实践,确定了最佳的工艺条件;同时对产品工艺设计要点及其对产品质量的影响进行了阐述.     

不同Cu含量Al-Cu合金的微观组织及DSC分析

利用差示扫描量热分析仪和场发射电子扫描显微镜,对不同Cu含量的Al-Cu合金微观组织和DSC曲线进行了分析研究。结果发现,在含Cu量为5%~40%的范围内,随着Cu含量的增加,Al-Cu合金的熔化潜热逐渐减小。亚共晶成分合金中,随着Cu含量的增加,初生-αAl相所占比例逐渐减小,共晶组织所占比例随之增加。     

铝及铝合金涂装前处理的研究现状及展望

涂装前的处理关系到最终产品的质量。重点介绍了铝及铝合金表面无铬磷酸盐化学转化处理、稀土转化处理和有机硅烷化处理的特点及应用情况，并对今后的发展方向进行了展望。     

电梯发运排队叫号系统的实现

从收集电梯成品箱供应商运输．库存，发运三个环节存在的问题做为切人点．从提高效率．提高发运产能优化流程等方面考虑．设计。电梯发运管理”辅助软件——电梯发运排队叫号系统。     

沙湾水电站厂房后坡变形体地表三维监测分析

通过对木里河沙湾水电站厂房后边坡变形体的地表三维监测资料的分析,可以判断其变形是由于阀室交通洞的集中排水造成的,由于厂房边坡开挖、S216省道改线和雨季降水入渗等因素的共同作用,进一步加剧了边坡的变形。从跨年度监测资料分析来看,变形体的变形量虽呈季节周期性变化,但已趋于收敛,在不改变坡体边界条件的工况下,降水对坡体稳定性的敏感度已显著降低。     

间接电解氧化合成邻氯苯甲醛

采用Ｍｎ（Ⅲ）为氧化媒质，以邻氯甲苯为原料，苯做溶剂，在浓硫酸存在下，以甲丁基溴化铵为相转移催化剂，用间接电解氧化的方法合成了邻氯苯甲醛。通过正交实验考察了硫酸浓度、反应温度、反应时间、原料配比４个因素对产品收率的影响。确定最佳反应条件：硫酸浓度８．０ｍｏｌ．Ｌ＾－１，反应温度６３℃，原料配比：邻氯甲苯：「Ｍｎ＾３＋」为５：４，反应时间４ｈ，最高收率达５５％。