Continuous hydrolysis of modified wheat gluten in an enzymatic membrane reactor

BACKGROUND: The low solubility of wheat gluten is one of the major limitations to its use in food processing, and enzymatic hydrolysis has been found to be an effective way to prepare more soluble bioactive peptides from gluten. The aim of this study was to prepare bioactive peptides from modified wheat gluten (MWG) in a continuous enzymatic membrane reactor (EMR) that allowed rapid separation of low‐molecular‐weight peptides from hydrolysates, thus avoiding the disadvantages of batch reaction such as inefficient use of enzymes, inconsistent products due to batch‐to‐batch variation, substrate–product inhibition, low productivity and excessive hydrolysis. RESULTS: Wheat gluten was modified to decrease its lipid and starch contents in order to prevent membrane fouling. The optimal working conditions for Alcalase to hydrolyse MWG in the EMR were a substrate concentration of 20 g L^?1, an enzyme/substrate ratio of 0.03, an operating pressure of 0.04 MPa, a temperature of 40 °C and a pH of 9. The operating stability of the EMR (including residual enzyme activity, productivity and capacity) was high. The permeate fractions showed antioxidant activities that were mostly due to low‐molecular‐weight peptides. A simple theoretical kinetic model was successfully applied to the enzymatic hydrolysis of MWG in the EMR. CONCLUSION: Modification of wheat gluten made the continuous enzymatic membrane reaction more efficient and the EMR proved to be an effective means of producing peptides with particular properties and bioactivities. The permeate fractions (mainly < 1000 Da) were homogeneous and stable and also showed strong antioxidant activities. Copyright © 2011 Society of Chemical Industry     

Study on Electromagnetorheological Fluid Containing CuPc—Fe3O4 Nanoparticles Composite

Electromagnetorheological (EMR) fluids containing CuPc-Fe3O4 nanopareticles composite were prepared and their properties were studied. The results show that Δτ of this kind of EMR fluids increases with the increments of applied electric field , magnetic field and volume fraction of the nanoparticles composite, Δτhas an approximate linear relationship with γ.When an electric and magnetic field are applied simultaneously, the EMR fluids have a synergistic effect.The EMRfluids have a good long-term stability.     

Ni/TiO_2基电磁流变液的微粒质量分数对其性能、形貌的影响

研究不同微粒质量分数的电磁流变液的性能、形貌,分析性能与质量分数、剪切速率以及所加电、磁场强度的关系。研究表明:同成分电磁流变液在相同的外场作用下随质量分数的增加,其强度增加,最佳质量分数值为30%;在电、磁场作用下微粒的形貌随质量分数增加,微粒链逐渐变粗变多,随电磁场强度的增加其微粒链变粗变壮,并出现相互交织。     

Preparation of sesame peptide and evaluation of antibacterial activity on typical pathogens

The antibacterial activity of sesame peptides on common pathogen was evaluated. The preparation of sesame protein hydrolysate was carried out in an enzymatic membrane reactor followed by fractionation through several ultrafiltration stages to obtain desired peptide fractions and evaluation of their antibacterial activity using two pathogens namely, Pseudomonas aeruginosa and Bacillus subtilis. Potential sesame peptides were characterized by mass spectroscopy (TOF-MS) followed by determination of their corresponding amino acid compositions. Sesame peptide fraction of molecular mass less than 1 kDa exhibited significant inhibition against growth of P. aeruginosa as compared to B. subtilis. Thus, these findings confirm the bacteriostatic effect of sesame peptide on growth of pathogens which can be exploited in bacteriostat composition.     

空间电磁辐射的缝隙仿真建模技术研究

缝隙是电子设备产生电磁场泄漏的主要途径,要正确预测电子设备的电磁兼容性能,就必须考虑缝隙引起的电磁场泄漏.因此,本文提出了一种空间电磁辐射的缝隙仿真建模技术,同时提出了等效缝隙模型中结构尺寸及材料属性的确定规则;最后通过仿真案例验证了该方法的准确性.     

Determination of Heterocyclic Amines in Meat Matrices Using Enhanced Matrix Removal‐Lipid Extraction and Liquid Chromatography–Tandem Mass Spectrometry

A simple, fast, and efficient method, “enhanced matrix removal of lipids” (EMR‐lipid), was proposed, optimized, and validated for identifying five polar heterocyclic amines (HCAs) in meat samples that ranged from high‐protein (beef and chicken) to high‐fat (pork bacon) matrices. The protocol involves an initial solid–liquid phase extraction followed by a rapid dispersive solid‐phase extraction using EMR‐lipid sorbents and salting‐out partitioning. Acetonitrile containing formic acid at two levels (1% and 2%) efficiently extracted HCAs from different meat matrices. Liquid chromatography–tandem mass spectrometry (MS/MS) with selective reaction monitoring mode was developed for qualitative and quantitative analysis. The highest MS/MS responses and better peak separation of analytes were achieved by adjusting mobile phases to pH 3.0 with instrumental detection limits between 0.01 and 0.05 ng/mL. Good linearity of standard curves was obtained in both pure solvents and postspiked meat extracts between 0.5 and 50.0 ng/mL. The validation results showed good precision, accuracy, and sensitivity for detecting HCAs in spiked meat samples. Satisfactory recoveries of four HCAs were achieved: 65% to 111% in beef, 71% to 106% in bacon, and 42% to 77% in chicken. Matrix effects were also assessed and showed less than –20% of ion suppression in bacon extract, while a medium to high signal suppression was observed in beef (–37% to –55%) and chicken (–28% to –52%). This optimized EMR‐lipid method provides acceptable results and advantages for determining trace level HCAs in complex meat matrices.     

Feature Selection Method Based on Class Discriminative Degree for Intelligent Medical Diagnosis

By using efficient and timely medical diagnostic decision making, clinicians can positively impact the quality and cost of medical care. However, the high similarity of clinical manifestations between diseases and the limitation of clinicians’ knowledge both bring much difficulty to decision making in diagnosis. Therefore, building a decision support system that can assist medical staff in diagnosing and treating diseases has lately received growing attentions in the medical domain. In this paper, we employ a multi-label classification framework to classify the Chinese electronic medical records to establish corresponding relation between the medical records and disease categories, and compare this method with the traditional medical expert system to verify the performance. To select the best subset of patient features, we propose a feature selection method based on the composition and distribution of symptoms in electronic medical records and compare it with the traditional feature selection methods such as chi-square test. We evaluate the feature selection methods and diagnostic models from two aspects, false negative rate (FNR) and accuracy. Extensive experiments have conducted on a real-world Chinese electronic medical record database. The evaluation results demonstrate that our proposed feature selection method can improve the accuracy and reduce the FNR compare to the traditional feature selection methods, and the multi-label classification framework have better accuracy and lower FNR than the traditional expert system.     

改性电解锰渣-矿粉复合胶材料的制备及水化机理

电解锰渣(EMR)是金属锰湿法冶炼过程中产生的一种固体废物,其堆积量大,对环境造成了严重的污染。但电解锰渣中富含硫酸盐,依据其特性,可与矿粉(GGBFS)复合制备胶凝材料。以矿粉为主要原料,电解锰渣为矿粉的硫酸盐激发剂,熟石灰为碱激发剂,制备电解锰渣-矿粉复合胶凝材料。探究电解锰渣、矿粉和熟石灰的最佳配比,并在此基础上对电解锰渣在不同温度下煅烧改性,通过力学测试确定最佳煅烧温度。利用XRD、FT-IR、TG-DTG和SEM等表征方式分析胶凝材料的水化产物及水化机理,同时对硬化体进行毒性测试。结果表明：电解锰渣对矿粉有良好的激发作用,复合胶凝材料中电解锰渣、矿粉、熟石灰最佳质量配比为2︰7︰1,其28 d的抗压强度达到27.2 MPa,电解锰渣经350 ℃煅烧所制备的复合胶凝材料抗压强度达到30.5 MPa。复合胶凝材料的水化产物主要为钙矾石(AFt)和水化硅酸钙(C-S-H);28 d硬化体浸出液中的重金属浓度均在《生活饮用水卫生标准》(GB 5749—2022)标准限值内,复合胶凝材料具有良好的安全性。     

电子病历信息系统的分析和设计

从电子病历的概念和特点出发．结合本院实际情况对电子病历信息系统的功能进行深入分析和设计,提出系统总体结构设计图等,详细描述系统各功能模块,对加快电子病历信息系统的开发有一定的指导意义．对医院规范医疗行为和提高病案质量具有深远的现实意义,对电子病历信息系统的发展进行展望。     

基于区块链的电子医疗记录安全共享

针对电子医疗记录（EMR）共享面临的数据提供商集权化、患者数据管理显被动、互操作效率低、恶意传播等问题,提出一种基于区块链的电子医疗记录安全共享方法。首先,基于商用密码SM2数字签名算法提出一种更加安全高效的泛指定验证者签名证明（UDVSP）方案;然后,设计具有上传、验证、检索、撤销等功能的智能合约,构造基于区块链的电子医疗记录安全共享系统;最后,通过安全性分析和性能分析论证UDVSP方案和共享系统的可行性。安全性分析结果表明,所设计的UDVSP方案满足可证明安全性。性能评估结果表明,与现有常用的UDVSP/UDVS方案相比,节省至少87.42%的计算开销和93.75%的通信代价。区块链智能合约原型系统的仿真结果进一步论证了共享系统的安全性和高效性。