Identification of novel circulating coffee metabolites in human plasma by liquid chromatography-mass spectrometry

This study reports a liquid chromatography-mass spectrometry method for the detection of polyphenol-derived metabolites in human plasma without enzymatic treatment after coffee consumption. Separation of available standards was achieved by reversed-phase ultra performance liquid chromatography and detection was performed by high resolution mass spectrometry in negative electrospray ionization mode. This analytical method was then applied for the identification and relative quantification of circulating coffee metabolites. A total of 34 coffee metabolites (mainly reduced, sulfated and methylated forms of caffeic acid, coumaric acid, caffeoylquinic acid and caffeoylquinic acid lactone) were identified based on mass accuracy (<4 ppm for most metabolites), specific fragmentation pattern and co-chromatography (when standard available). Among them, 19 circulating coffee metabolites were identified for the first time in human plasma such as feruloylquinic acid lactone, sulfated and glucuronidated forms of feruloylquinic acid lactone and sulfated forms of coumaric acid. Phenolic acid derivatives such as dihydroferulic acid, dihydroferulic acid 4'-O-sulfate, caffeic acid 3'-O-sulfate, dimethoxycinnamic acid, dihydrocaffeic acid and coumaric acid O-sulfate appeared to be the main metabolites circulating in human plasma after coffee consumption. The described method is a sensitive and reliable approach for the identification of coffee metabolites in biological fluids. In future, this analytical method will give more confidence in compound identification to provide a more comprehensive assessment of coffee polyphenol bioavailability studies in humans.     

Study on the quantitative structureactivity relation-ship of C-10 substituted artemisinin (QHS)’s derivatives using rough set theory

The structure-activity relationship study of C-10 substituted artemisinin (QHS) derivatives that are used as antimalarial was performed with the RS (rough sets) method. An RS process is a concise nonlinear process, and it has broad application foreground in the data mining of nonlinear life courses. In this work, initially the parameters of C-10 substituted QHS’s derivatives were computed with the quantum chemistry method, and the information table was constructed from the parameters (condition attributes) and biological activity (decision attributes). Based on the analysis of rough set theory, the core and reduction of attributes sets were obtained. Then the decision rules were extracted and the struc-ture-activity relationship was analyzed. As a nonlinear system, RS theory can extract the special rela-tion in the database. It has the advantage of being nonlinear over multiple linear regression (MLR), principal component analysis (PCA), partial least square (PLS), etc., and the advantage of obtaining results with unambiguous physical meanings over artificial neuron networks (ANNs), etc. The result obtained in this study is instructive to the study of pharmacodynamics, resistance mechanism of QHS and development of QHS’s derivatives.     

Determination of engineered nanoparticles on textiles and in textile wastewaters

Textile materials with engineered nanoparticles (ENPs) have excellent properties as they are antibacterial, antimicrobial, water resistant and protective. The textile industry has recognized the importance and the advantages of ENPs, so they comprise one of the fastest developing branches of processing.The most important sources of ENPs released to the environment from textiles are textile-industry wastewaters and waters from large hospital or hotel laundries. In addition, waste textile materials coated with ENPs present a threat to the environment, if such materials are not properly handled and disposed of after use.Currently, the toxicity and the potential harm of ENPs widely applied on textiles are not thoroughly investigated and/or eliminated. Consequently, there is an urgent need to define the most appropriate analytical methods for monitoring ENPs on textiles.This review presents the most important techniques for monitoring ENPs on textile materials and in textile-wastewater samples, from the perspective of protecting the environment and human health.     

珊瑚色诺卡氏菌全细胞催化（RS）-4-氟苯甘氨酸去消旋化为（S）-4-氟苯甘氨酸

珊瑚色诺卡氏菌CGMCC 4.1037 全细胞能够催化4-氟苯甘氨酸的（R）-对映体立体反转为（S）-对映体,相反方向的反应不能发生。研究了反应条件对（R）-4-氟苯甘氨酸立体反转的影响。在最优反应条件下,5mmol/L（R）-4-氟苯甘氨酸和10mmol/L（RS）-4-氟苯甘氨酸分别立体反转和去消旋化为（S）-4-氟苯甘氨酸,产率为52%和63%,ee为99.5%和99.2% 。（RS）-4-氟苯甘氨酸的去消旋化过程是通过珊瑚色诺卡氏菌CGMCC 4.1037 全细胞中的两个酶催化反应实现的。（R）-氨基酸氧化酶催化（R）-4-氟苯甘氨酸氧化脱氨形成4-氟苯甲酰甲酸,（S）-氨基酸转移酶催化4-氟苯甲酰甲酸转氨化为（S）-4-氟苯甘氨酸。讨论了4-氟苯甘氨酸两个对映体的代谢途径。     

Application of ZnO‐Al2O3 Nanocomposite as Nanocatalyst for Photodegradation of Acid Violet 5B

ZnO‐Al₂O₃ nanocomposite (ZANC) is used as nanocatalyst for photodegradation of acid violet 5B (AV5B) as an industrial dye. The experimental data shows that the degradation of AV5B is accelerated by ZANC and UV light. The effects of various parameters such as pH, hydrogen peroxide and ethanol are investigated on the photodegradation efficiency. Photocatalytic degradation rate of AV5B is increased by ethanol and hydrogen peroxide. Based on the kinetic studies, the rate constant of the photodegradation reaction is estimated 2.829 × 10^‐1 min^‐1.     

Controversial Variable Node Selection-Based Adaptive Belief Propagation Decoding Algorithm Using Bit Flipping Check for JSCC Systems

An end-to-end joint source–channel (JSC) encoding matrix and a JSC decoding scheme using the proposed bit flipping check (BFC) algorithm and controversial variable node selection-based adaptive belief propagation (CVNS-ABP) decoding algorithm are presented to improve the efficiency and reliability of the joint source–channel coding (JSCC) scheme based on double Reed–Solomon (RS) codes. The constructed coding matrix can realize source compression and channel coding of multiple sets of information data simultaneously, which significantly improves the coding efficiency. The proposed BFC algorithm uses channel soft information to select and flip the unreliable bits and then uses the redundancy of the source block to realize the error verification and error correction. The proposed CVNS-ABP algorithm reduces the influence of error bits on decoding by selecting error variable nodes (VNs) from controversial VNs and adding them to the sparsity of the parity-check matrix. In addition, the proposed JSC decoding scheme based on the BFC algorithm and CVNS-ABP algorithm can realize the connection of source and channel to improve the performance of JSC decoding. Simulation results show that the proposed BFC-based hard-decision decoding (BFC-HDD) algorithm (ζ = 1) and BFC-based low-complexity chase (BFC-LCC) algorithm (ζ = 1, η = 3) can achieve about 0.23 dB and 0.46 dB of signal-to-noise ratio (SNR) defined gain over the prior-art decoding algorithm at a frame error rate (FER) = 10−1. Compared with the ABP algorithm, the proposed CVNS-ABP algorithm and BFC-CVNS-ABP algorithm achieve performance gains of 0.18 dB and 0.23 dB, respectively, at FER = 10−3.     

尺寸排阻色谱柱上尿素梯度复性全长人PPAR-γ

建立尺寸排阻色谱柱上尿素梯度复性全长人PPAR-γ重组蛋白的方法。利用尺寸排阻色谱柱上尿素梯度除去变性剂直接复性变性蛋白。添加尿素和精氨酸抑制聚集以提高复性产率,加入Zn2+促进变性蛋白形成正确折叠。复性后,重组蛋白的尺寸排阻色谱保留体积增大;紫外光谱最大吸收波长从234.0nm变为280.8nm;基质辅助激光解析-电离飞行时间质谱分析重组蛋白的完整性,测得分子量与理论值一致;放射配体受体结合饱和实验测得解离常数(Kd)为89±4nmol/L;复性产率为52.7%。结果表明本文所建立的方法能成功用于复性变性全长人PPAR-γ,获得可用于结构和功能研究的具有生物学活性的全长人PPAR-γ蛋白。     

HPLC测定西宁市鱼产品中的孔雀石绿与结晶紫

探索了西宁市鱼类产品中孔雀石绿与结晶紫的高效液相色谱荧光检测方法,方法在0.1ng/g-700ng/g范围内具有很好的线性关系,相关系数r为0.9998,定量限为0.5μg/kg.采用不同的鱼类产品进行验证,孔雀石绿的回收率在88％-94％之间,相对标准偏差(RSD)为3.15％-4.87％.结晶紫的回收率在94％-108％,相对标准偏差(RSD)为2.54％-4.05％.本法提取快捷、简便,适用于大批量的抽样检测,可检测出鱼类样品中痕量的孔雀石绿,为水产养殖提供可行的监测手段,为鱼类中孔雀石绿的检测标准的制定提供依据.     

Manifestation of Peripheral NO2-Substitution in the Resonance Raman Scattering Spectra of Tetraarylporphyrins

The resonance Raman scattering (RS) spectra of a series of nitro-substituted derivatives of the free base of tetraphenyl porphyrin that were obtained on continuous excitation near the Soret band have been investigated. For the molecules in which the NO₂ group is located in the -position of pyrrole rings or in the para-position of meso-phenyl substituents, an intense line of the mode within the range 1340–1355 cm^–1 is discovered. Based on the obtained resonance RS spectra of the diprotonated derivatives of nitro-tetraarylporphyrins, it is assigned to symmetrical vibration of a nitro group ( _s NO₂). Activation of the _s NO₂ vibration is indicative of the existence of the -delocalization effect for a number of nitro-substituted porphyrins at which interaction between the molecular orbitals of the nitro-substituents and the porphyrin macrocycle occurs. Moreover, the -delocalization is typical of both direct addition of a nitro-substituent to the porphyrin ring and of its binding via a meso-phenyl group. The results obtained demonstrate the informative value of the resonance RS spectroscopy for creating and studying model donor–acceptor systems with the participation of porphyrins.