唑螨酯的毒性及研究进展

唑螨酯是一种高效、广谱、非内吸性的苯氧基吡唑类杀螨剂,广泛用于果蔬害螨防治。但近年来因为不合理使用导致残留及安全性问题。笔者综述了唑螨酯的应用、残留、代谢降解及毒性研究进展,以期对后续研究提供参考。     

Enhanced bioactivity of Zanthoxylum schinifolium fermented extract: Anti-inflammatory,anti-bacterial,and anti-melanogenic activity

1. Download : Download high-res image (151KB)
2. Download : Download full-size image

     

A reliable and sensitive time-resolved fluorescent immunochromatographic assay (TRFICA) for ochratoxin A in agro-products

Immunochromatographic assays (ICAs) are considered as a suitable diagnostic tool for the detection of mycotoxins. Mycotoxins and especially, ochratoxin A are analytes with more demanding sensitivity requirements. To enhance the sensitivity of current immunochromatographic assays for ochratoxin A (OTA), a novel sensitive ICA was developed in this study. In the assay, microspheres enclosing fluorescent europium (III) [Eu(III)] nanoparticles (EuNPs) were used as a label for OTA monoclonal antibody (OTA-mAb) conjugation. Accordingly, assay was called time-resolved fluorescent immunochromatographic assay (TRFICA). The test strip was composed of three parts: a sample pad, nitrocellulose membrane and an absorbent pad. As for detection, a proper concentration of conjugated microspheres was pipetted into the microtube and sample extract was added to it. Then the strip was inserted into the tube and the fluid flow along the strip. The TRFICA results were obtained in 8 min and read by a portable TRFICA strip reader. The established method allows quantitative determination of OTA with limit of detection as low as 1.0 μg kg⁻¹ in the samples. For validation, spiked samples including wheat, maize, soybean and rice were respectively assayed by TRFICA and a standard high performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD), and good agreement of results was obtained between two methods.     

5种香蕉果肉多酚的抗氧化活性和抑制α-葡萄糖苷酶活性

目的：比较不同品种香蕉果肉多酚的活性差异。方法：超声萃取5种香蕉果肉多酚，利用超高效液相色谱分析酚类组成，分析其抗氧化能力和对α-葡萄糖苷酶活性的抑制能力。结果：5种香蕉果肉间的多酚含量、黄酮含量和单宁含量差异显著（P＜0.05）；在5种香蕉果肉中检测出8种主要单体酚，包括4种酚酸及其衍生物和4种黄酮类化合物；5种香蕉果肉多酚具有一定的DPPH自由基清除能力、ABTS自由基清除能力和铁离子还原能力，均能抑制α-葡萄糖苷酶活性，主要活性成分芦丁、儿茶素与抑制能力呈显著正相关（P＜0.05）。南角42号香蕉果肉多酚的抗氧化能力和抑制α-葡萄糖苷酶活性的能力最强，通过混合型抑制的方式抑制酶活，其与α-葡萄糖苷酶的相互作用为放热反应。结论：香蕉果肉多酚具有很好的抗氧化能力和对α-葡萄糖苷酶活性的抑制能力，有望成为良好的α-葡萄糖苷酶选择性抑制剂。     

亲水胶体对海绵蛋糕中晚期糖基化终末产物的抑制作用

为探究亲水胶体对晚期糖基化终末产物（advanced glycation end products,AGEs）生成的抑制作用,首先采用牛血清白蛋白（bovine albumin,BSA）-果糖、BSA-葡萄糖、BSA-丙酮醛（methylglyoxal,MGO）、BSA-乙二醛4 个化学模型,考察9 种经典亲水胶体在化学模型中的抗糖基化能力,筛选出抑制效果最佳的海藻酸（alginic acid,ALA）和黄原胶（xanthan gum,XG）作为研究对象,探究不同亲水胶体添加量（0.25%、0.5%、1.0%、1.5%、2.0%）及烘焙温度、时间对海绵蛋糕品质属性、AGEs形成和蛋白氧化产物的影响。明确最佳烘焙温度和时间为180 ℃、40 min,在此条件下分别添加0.5% ALA或2.0% XG能够显著降低海绵蛋糕中的荧光AGEs、非荧光AGEs和蛋白氧化产物含量。同时,ALA和XG的添加能够改善蛋糕的质构,提高蛋糕的水分含量。ALA和XG是一类很有前途的天然AGEs抑制剂,可以在烘焙之前添加至原料中,以减少烘焙食品中AGEs的生成。     

共轭亚油酸的功能性质及安全性评价

介绍了共轭亚油酸及其对健康的益处，综述了共轭亚油酸对动物和人体机体组成影响的研究进展，并讨论了共轭亚油酸添加物的安全性问题。研究认为，共轭亚油酸对健康和机体组成等均具有较好的作用，但人体服用共轭亚油酸的安全性问题有待进一步的研究。     

开关磁阻电机技术及其在离心机中的应用

本文描述了一种新型离心机及其电机驱动系统,其中,电机驱动系统包括：开关磁阻电机、位置传感器、微机控制器、功率变换器。其中微机控制器与传感器相连,并根据运行参数调整所接收的控制信号,形成调整控制信号;功率变换器与微机控制器相连,根据调整控制信号生成驱动开关磁阻电机的电机驱动信号。应用此新型开关磁阻电机技术,解决了现有技术中离心机电机驱动系统控制精度差较差的问题,具有起动转矩大,起动电流低,结构简单等特点。     

Rheological and viscoelastic properties of corn starch suspension modified by hydrothermal process: Impacts of process intensification

Rheological properties of starch suspension and particle size distribution of treated starch granules under the same conditions (2 bar and 20 min) by direct vapour-heat moisture treatment (DV-HMT), Reduced-Pressurized Heat Moisture Treatment (RP-HMT) and Instantaneous Controlled Pressure Drop Process (DIC) were investigated. DV-HMT and RP-HMT were compared to DIC process in order to determine the role of the vacuum pressure steps before and after injection of live steam on the starch powder. For all treated starches an increase of the particle size of granules was observed, a reduction of the consistency index and of the conservative modulus, compared to the untreated one. This difference becomes so important with increasing of process intensification. Relaxation spectra evaluated from the generalized Maxwell model implied a drift to shorter relaxation time for treated starch suspension than the native one. A decrease in peak intensity H(λ) of relaxation spectra with increase of intensification of processes was observed which conclude that the modified starch suspension moving away from a stable state like gel according to the following order DV-HMT < RP-HMT < DIC. The effect of DIC process seems to be more intense than the two other treatments. This difference can be attributed to the mechanical effect induced by the abrupt decompression towards vacuum after treatment.