Alginate‐Based Emulsion Template Containing High Oil Loading Stabilized by Nonionic Surfactants

Oil‐in‐water (O/W) emulsion‐gel systems containing high oil payloads are of increasing interest for food applications because of the reduction in encapsulation cost, consumption frequency or volume of food products. This study shows a facile approach to prepare stable alginate‐based O/W emulsions at high oil loading using a mixture of nonionic surfactants (Tween 80 and Span 20) as a template to form gelled‐emulsions. The synergistic effects of alginate and surfactants on the O/W emulsion properties were evaluated in terms of oil droplet size and emulsion stability. At 2% (w/v) of alginate and 1% (w/v) of surfactants, the size distribution of oil droplets was narrow and monomodal, even at an oil loading of 70% (v/v). The emulsions formed were stable against phase separation. The oil droplet size could be further reduced to below 1 μm using a high‐shear homogenizer. The emulsions formed could be easily molded and gelled into solids of different shapes via ionic gelation. The findings of this study create possible avenues for applications in food industries.     

低聚糖和多酚结合偏最小二乘判别分析鉴别油菜蜜产地

采用气相色谱-串联质谱技术测定油菜蜜中6 种低聚糖成分,高效液相色谱-串联质谱技术测定油菜蜜中18 种酚酸物质,并结合偏最小二乘判别分析（partial least square-discrimination analysis,PLS-DA）对来自湖北钟祥市、江苏盐城市、青海刚察县3 个具有显著地理、气候、环境差异的51 个油菜蜜样本进行产地鉴别。方差分析结果显示：3 个产地油菜蜜中松二糖含量具有显著性差异,且青海刚察油菜蜜低聚糖含量相对偏高;油菜蜜的18 种多酚类物质中大多数具有显著的地理差异性且湖北钟祥的油菜蜜中多酚含量相对偏高。多元统计分析结果显示多酚具有显著的地理特征性。油菜蜜中低聚糖和多酚的含量结合PLS-DA产地鉴别的预测精度可达到97%。     

Effect of temperature and chainlength on the densities and molal volumes ofn-alkyl chlorides

The densities ofn-alkyl chlorides from pentyl chloride to hexadecyl chloride were determined at temperatures between 15–80°C at 5°C intervals. The densities increase linearly with temperature and chainlength. A four-constant equation, V=n/(−3.6640 × 10⁻⁵ T+0.07151)+1/(−5.6526 × 10⁻⁵ T+0.04243), was formulated. This formula accurately predicted the molal volume and, hence, the density for all then-alkyl chlorides at any temperature within the range.     

Dynamic mechanical analysis studies of the interphase

The dynamic mechanical properties of unidirectional glass-fiber-reinforced polyester measured along the fiber direction were recently investigated. In the same polyester, the type of organosilane coated on the glass fiber, the amount of organosilane, the fiber volume fraction, and the fiber diameter affect the value of the loss tangent, tan δ, at the glass-transition temperature of the glass-fiber-reinforced polyester. The interfacial shear strength and the tan δ at the glass-transition temperature of the glass-fiber-reinforced polyester show good correlation suggesting that the latter can be used to characterize the quality of the interphase. Factors affecting the glass-transition temperature and the application of Zorowski and Murayama's equation in the characterization of the interfacial adhesion are also discussed.     

Glass Structure Changes in CO$_{2}$ -Laser Writing of Long-Period Fiber Gratings in Boron-Doped Single-Mode Fibers

We investigate in detail the process of CO₂-laser writing of long-period fiber gratings (LPFGs) in unannealed and annealed boron-doped fiber samples by using repeated scanning of CO₂-laser pulses. We find that the writing dynamics depends strongly on the CO₂-laser energy density and the annealing temperature of the fiber. Our results from analyzing the writing dynamics reveal the relative importance of various physical effects arising from glass structure changes due to different writing conditions and thus provide a better understanding of the formation and the properties of CO₂-laser written LPFGs.     

探讨采用绿色和非绿色模塑料封装的功率MOSFET器件之性能

绿色指令推动半导体厂家在其微电子产品封装中摒弃氧化锑、阻燃剂及卤代化合物之类的环境有害物质,然而人们可能担心,绿色封装中的新化学材料有可能影响半导体器件的性能.本文中通过热压应力测试对采用绿色和非绿色环氧模塑料(EMC)封装的功率晶体管的性能进行了评测.实验表明,绿色器件的电气和物理性能都优于非绿色器件.     

An automated fluorescent PCR method for detection of shiga toxin-producing Escherichia coli in foods

An automated fluorescence-based PCR system (a model AG-9600 AmpliSensor analyzer) was investigated to determine whether it could detect Shiga toxin-producing Escherichia coli (STEC). The AmpliSensor PCR assay involves amplification-mediated disruption of a fluorogenic DNA signal duplex (AmpliSensor) that is homologous to conserved target sequences in a 323-bp amplified fragment of Shiga toxin genes stx1, stx2, and stxe. Using the Amplisensor assay, we detected 113 strains of STEC belonging to 50 different serotypes, while 18 strains of non-Shiga-toxin-producing E. coli and 68 strains of other bacteria were not detected. The detection limits of the assay were less than 1 to 5 CFU per PCR mixture when pure cultures of five reference strains were used and 3 CFU per 25 g of food when spiked ground beef samples that were preenriched overnight were used. The performance of the assay was also evaluated by using 53 naturally contaminated meat samples and 48 raw milk samples. Thirty-two STEC-positive samples that were confirmed to be positive by the culture assay were found to be positive when the AmpliSensor assay was used. Nine samples that were found to be positive when the PCR assay was used were culture negative. The system described here is an automated PCR-based system that can be used for detection of all serotypes of STEC in food or clinical samples.     

The effects of zinc and copper salts on Cyprinus carpio and Ctenopharyngodon idellus

The effects of zinc and copper salts on the survival of the two species of freshwater fish, common carp, Cyprinus carpio, and grass carp, Ctenopharyngodon idellus, were investigated. It was discovered that the levels of tolerance to the concentration of the metals were species-specific. Cyprinus carpio was found to be more susceptible to copper, whereas Ctenopharyngodon idellus was more susceptible to zinc. In general, copper was more toxic than zinc, as revealed by the survival times. The body and the gills of dead fish seemed to be covered by a veil-like film which looked like coagulated mucus and which was formed by the heavy-metal ions reacting with some constituents of the mucus and which was formed by the heavy-metal ions reacting with some constituents of the mucus secreted by the gill. The histopathological assessment of the gill and liver of Cyprinus carpio was also carried out. Particles were observed around the gills of the dead fish treated with zinc and copper salts, although no other major changes were found in the gill. Several histopathological changes were observed in the livers, including the presence of particles. The symptoms of the liver suggested that the internal injury was also an important feature of the intoxicants.