Green synthesis of graphene oxide sheets decorated by silver nanoprisms and their anti-bacterial properties

A widely soluble graphene oxide sheets decorated by silver nanoprisms were prepared through green synthesis at the room temperature using gelatin as reducing and stabilizing agent. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy and fluorescence spectra. The results demonstrate that these silver-nanoprisms assembled on graphene oxide sheets are flexible and can form stable suspensions in aqueous solutions. Furthermore, the formation mechanism of soluble graphene oxide sheets decorated by silver nanoprisms was successfully explained. The anti-bacterial properties of graphene oxide sheets decorated by silver nanoprisms were tested against Escherichia coli. This work provides a simple and “green” method for the synthesis of graphene oxide sheets decorated by silver nanoprisms in aqueous solution with promising antibacterial property.     

蚕丝蛋白和明胶复合组织工程材料与肝细胞相容性的实验研究

目的：研究蚕丝蛋白-明胶三维材料支架对人永生化肝细胞系QZG贴附及增殖的影响。方法：采用四氮唑盐比色法（MTT）、细胞计数法检测QZG细胞在纯蚕丝生物材料上与在蚕丝蛋白-明胶复合材料上的增殖情况,用扫描电镜观察QZG细胞在两种三维生物材料上的贴附与增殖情况。结果：QZG细胞可以在蚕丝蛋白生物材料贴附及增殖,在引入明胶的蚕丝蛋白材料上细胞贴附更紧密,增殖更明显。结论：蚕丝蛋白与明胶复合材料支架具有良好的细胞贴附性能,通过改进在肝组织工程应用方面将具有一定应用前景。     

蚕丝蛋白和明胶复合组织工程材料与肝细胞相容性的实验研究

目的:研究蚕丝蛋白-明胶三维材料支架对人永生化肝细胞系QZG贴附及增殖的影响。方法:采用四氮唑盐比色法(MTT)、细胞计数法检测QZG细胞在纯蚕丝生物材料上与在蚕丝蛋白-明胶复合材料上的增殖情况,用扫描电镜观察QZG细胞在两种三维生物材料上的贴附与增殖情况。结果:QZG细胞可以在蚕丝蛋白生物材料贴附及增殖,在引入明胶的蚕丝蛋白材料上细胞贴附更紧密,增殖更明显。结论:蚕丝蛋白与明胶复合材料支架具有良好的细胞贴附性能,通过改进在肝组织工程应用方面将具有一定应用前景。     

基于魔芋葡甘聚糖微球的胶原覆层型微载体的制备研究

以魔芋葡甘聚糖(KGM)微球为基质,用1,4-丁二醇二缩水甘油醚将KGM微球进行活化,将胶原覆层到微球上,对胶原覆层进行再次交联,得到覆层均匀、稳定的微载体.通过四因素三水平的正交回归组合试验设计,考察了活化时间、蛋白质用量、偶联时间、交联剂用量对微载体细胞培养效果的影响.以Vero细胞培养效果为指标,制备胶原包被微载体的最佳工艺为活化时间5h、蛋白用量1∶0.1(球:蛋白)、偶联时间5h、交联剂用量每1gKGM加入0.5ml交联剂.在最优制备条件下,培养Vero细胞最大细胞密度可达到1.7×106 cells/ml,证明了胶原覆层的KGM微球作为动物细胞培养的微载体具有可行性.     

Reconstruction of radial bone defect using gelatin sponge and a BMP-2 combination graft

Many bioactive molecules like recombinant human bone morphogenetic protein 2 (rhBMP-2) have been developed for mineralized bone grafts, for which proper scaffolds are necessary to successfully apply the bioactive molecules. In this study, we tested the osteogenic efficacy of rhBMP-2 produced in-house in combination with gelatin sponge as the scaffold carrier in a rabbit radial defect model. The efficacy of the rhBMP-2 was determined by alkaline phosphatase activity assay of C2C12 cells. Two groups of ten rabbits each were treated with rhBMP-2/gelatin sponge, or gelatin sponge only. At 4 weeks, rhBMP-2/gelatin sponge grafts showed more bone regeneration than gelatin sponge grafts, as determined by X-ray radiography, micro-computed tomography, and histological analyses. At 8 weeks, rhBMP-2/gelatin sponge grafts exerted much stronger osteogenic effects. The study demonstrates the improved osteogenic efficacy of the rhBMP-2/gelatin sponge grafts in a rabbit radial bone defect model acting as a bone-inductive material. [BMB Reports 2013; 46(6): 328-333]     

624例宁波市基层地区女性阴道感染调查分析

目的调查宁波市基层地区女性阴道感染的分布情况,为基层卫生医疗机构制订规范的阴道感染诊治方案提供参考。方法采用生理盐水涂片法和预成酶谱生化检测对624例基层女性患者的阴道分泌物进行联合检测,并记录患者的年龄、职业等情况。结果检出阴道感染患者425例,随着清洁度数的升高,各种阴道感染的检出率呈明显递增趋势,清洁度I~II患者BV、VVC、BV＋VVC的检出率明显低于清洁度III~IV的患者;单纯感染患者295例（69.41%）,其中VVC患者105例（24.70%）,BV患者88例（20.70%）,厌氧菌增殖52例（12.24%）,TV患者24例（5.65%）,其他感染患者26例（6.12%）。混合感染患者130例（30.59%）,其中BV＋VVC患者109例（25.65%）,BV＋TV患者21例（4.94%）;不同年龄组阴道感染发病率比较差异有统计学意义,20岁以下年龄组检出率最低,21~40岁年龄段检出率最高,尤其是BV、VVC、BV＋VVC患病率明显高于其他年龄组。结论基层地区各种阴道感染的发病率均处于较高水平,应加强基层地区女性阴道感染防治的健康教育,规范基层医疗机构的诊治方案,常规涂片镜检联合预成酶谱生化检测技术操作简单、快速、准确,可给临床医生提供科学明确的诊断依据,特别适宜在基层地区广泛推广。     

Identification of Peptidases in Highly Pathogenic vs. Weakly Pathogenic Naegleria fowleri Amebae

Naegleria fowleri, a free‐living ameba, is the causative agent of Primary Amebic Meningoencephalitis. Highly pathogenic mouse‐passaged amebae (Mp) and weakly pathogenic axenically grown (Ax) N. fowleri were examined for peptidase activity. Zymography and azocasein peptidase activity assays demonstrated that Mp and Ax N. fowleri exhibited a similar peptidase pattern. Prominent for whole cell lysates, membranes and conditioned medium (CM) from Mp and Ax amebae was the presence of an activity band of approximately 58 kDa that was sensitive to E64, a cysteine peptidase inhibitor. However, axenically grown N. fowleri demonstrated a high level of this peptidase activity in membrane preparations. The inhibitor E64 also reduced peptidase activity in ameba‐CM consistent with the presence of secreted cysteine peptidases. Exposure of Mp amebae to E64 reduced their migration through matrigel that was used as an extracellular matrix, suggesting a role for cysteine peptidases in invasion of the central nervous system (CNS). The collective results suggest that the profile of peptidases is not a discriminative marker for distinguishing Mp from Ax N. fowleri. However, the presence of a prominent level of activity for cysteine peptidases in N. fowleri membranes and CM, suggests that these enzymes may serve to facilitate passage of the amebae into the CNS.     

明胶颗粒凝集试验联合ELISA法在梅毒检测中的应用价值

目的分析明胶颗粒凝集试验(TPPA)联合酶联免疫吸附试验(ELISA)在梅毒检测中的应用价值。方法选择我院2015年1月至2018年12月收治的128例疑似梅毒患者为研究对象,将其中43例临床确诊患者纳入梅毒组,余下85例为非梅毒组,全部受试者均接受ELISA法联合TPPA检测,比较单独ELISA法和ELISA联合TPPA检测的结果。结果梅毒组患者中ELISA法诊断阳性35例,阴性8例;ELISA联合TPPA诊断阳性42例,阴性1例;ELISA法假阳性率14.63%(6/41),明显高于ELISA联合TPPA法的2.33%(1/43),差异有统计学意义(χ~2=4.163,P=0.041)。ELISA联合TPPA诊断梅毒的特异性、敏感性、阴性预测值及阳性预测值分别为98.82%、97.67%、98.82%、97.67%,均显著高于单独ELISA检测的92.94%、81.40%、90.80%、85.37%,差异均有统计学意义(χ~2=143.650、6.081、5.575、4.163,P0.001、=0.014、=0.018、=0.041)。结论 ELISA适用于大批量梅毒筛查,TPPA法的特异性及敏感性高,可作为梅毒血清抗体检测的确认试验。二者联合检测能够提高梅毒诊断效能,具有较高的应用价值。     

Critical helix content in gelatin gels

Aqueous gelatin solutions of different concentrations have been investigated at various quench temperatures by viscosity measurements to determine the gel times and by optical rotation measurements to derive the evolution of the helix content by reference to native collagen. As a result, it appears that the gelation of the different aqueous gelatin solutions tested takes place at a common helix concentration independent of the initial gelatin concentration and quench temperature. Further, for each concentration, the dependence of gel time as a function of quench temperature has revealed the existence of two domains: a higher temperature domain where gel times increase strongly with quench temperature and a lower temperature domain where gel times are short and only slightly dependent on quench temperature.     

Rhizopus delemar Lipase in Microemulsion-based Organogels: Reactivity and Rate-Limiting Study

The reactivity of Rhizopus delemar lipase immobilized in sodium bis(2-ethylhexyl) sulfosuccinate microemulsion-based organogels (MBGs) was investigated as a function of the water content in the gel. Gelatin was used as the gelling component of the MBGs. The maximal reaction rate of 6.5 μM s^-1 was obtained at a W_G (molar ratio of water to AOT in the MBG phase) value of 100. In the experimental W_G conditions, the reaction proceeded under an effectiveness factor of 0.02 to 0.04 giving the reaction-limiting regime.