Impact of Low-temperature Storage on Volatile Flavor Compounds in Prepared Pork Products

[Objectives]This study was conducted to explore the dynamic changes of volatile flavor compounds in prepared pork during storage at different low-temperature conditions.[Methods]Prepared pork was stored at 4,-4 and-18℃.The volatile flavor compounds of prepared pork were determined by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)at days 0,7,14,21 and 28,and relative odor activity value(OAV),principal component analysis(PCA)and cluster analysis(CA)were combined to analyze changes in volatile flavor compounds of prepared pork during storage.[Results]The total number of volatile flavor compounds gradually decreased with the prolongation of the storage period,and OAV analysis identified 22 key flavor compounds(OAV≥1).The results of PCA and CA showed that 2-methyl-1-butanol,1-octen-3-ol,linalool,cineole,hexanal and nonanal were the main key flavor components,and the degree of flavor degradation was low under both superchilling and freezing conditions.After 28 days of storage,the alcohol content in the chilling group was significantly higher than other two groups,and the overall content of volatile flavor compounds was also significantly higher than other two groups,indicating that the-4℃chilling storage was more favorable for maintaining the overall flavor of prepared pork.[Conclusions]This study provides a theoretical basis for finding a better storage method for prepared meat products.

Study on Effects of Curing Process on Characteristics of Marinated Beef Products

[Objectives]This study was conducted to compare the effects of different curing processes on the characteristics of marinated beef.[Methods]Marinated beef was obtained by two curing processes:static curing and injection and vacuum tumbling curing.The effects of the two curing processes on the production rate,curing absorption rate,water content,soluble protein content,amino acid nitrogen content,texture characteristics and microstructure of the product were compared.[Results]Compared with static curing,the production rate of marinated beef increased by 10%,the curing absorption rate increased by 28%,the texture and microstructure were improved,and the water content increased,while the soluble protein content decreased.As a result,the sensory score was higher.There was no significant difference in the content of amino acid nitrogen,but it decreased compared with raw meat.To sum up,injection and vacuum tumbling curing is more conducive to the processing of marinated beef.[Conclusions]This study provides a theoretical basis for the industrial production of marinated beef,and lays a foundation for in-depth exploration of injection and vacuum tumbling curing technique of marinated beef.

Distributed MPC for Reconfigurable Architecture Systems via Alternating Direction Method of Multipliers

This paper investigates the distributed model predictive control(MPC)problem of linear systems where the network topology is changeable by the way of inserting new subsystems,disconnecting existing subsystems,or merely modifying the couplings between different subsystems.To equip live systems with a quick response ability when modifying network topology,while keeping a satisfactory dynamic performance,a novel reconfiguration control scheme based on the alternating direction method of multipliers(ADMM)is presented.In this scheme,the local controllers directly influenced by the structure realignment are redesigned in the reconfiguration control.Meanwhile,by employing the powerful ADMM algorithm,the iterative formulas for solving the reconfigured optimization problem are obtained,which significantly accelerate the computation speed and ensure a timely output of the reconfigured optimal control response.Ultimately,the presented reconfiguration scheme is applied to the level control of a benchmark four-tank plant to illustrate its effectiveness and main characteristics.

Effects of Heat Treatment on Processing Characteristics of Pork

[Objectives]This study was conducted to explore the effects of heat treatment on processing characteristics of pork.[Methods]The effects of low-temperature long-term cooking(LTLT),high-temperature vacuum cooking,high-temperature cooking and high-temperature steaming on some indexes of pork products were studied,and principal component analysis was carried out.[Results]LTLT had significant effects on the total sensory score,moisture content,cooking loss rate,a value,shear force,and TBARS of pork,and the corresponding optimal product indicators were 71.40 points,72.36%,14.20%,4.79,7089.87 g,and 0.05 mg/kg,respectively.The microstructure changes in the LTLT group were relatively small,as the muscle fiber structure was relatively dense and uniform,and the gaps between muscle fibers were small.A total of 30 volatile flavor compounds were detected in the four groups,mainly alcohols,alkenes,alkanes,lipids,ketones,and aldehydes,and the LTLT group had more types and high contents.PCA analysis showed that the sensory evaluation,moisture content,elasticity,a value and LTLT were positively correlated with principal component 1.[Conclusions]Various indexes comprehensively showed that the LTLT group had better meat color,flavor,texture characteristics and lower oxidation degree than traditional cooking and steaming methods,which provides a theoretical reference for its large-scale application in the processing of prepared meat products.

Coking kinetics and influence of reaction-regeneration on acidity, activity and deactivation of Zn/HZSM-5 catalyst during methanol aromatization

The coking kinetics and reaction-regeneration on Zn/HZSM-5 （Zn/HZ） catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene （BTX） yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.

Studies on the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells

OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells(HSCs).METHODS Normal human Chang liver cells and human hepatic stellate cell line,LX-2 cells were treated with SRT1720(10μmol·L^(-1))and AICAR(500μmol·L^(-1))prior to ethanol(50 mmol·L^(-1)) for 24 and 48 h.Cell viability was analyzed by methyl thiazolyl tetrazolium assay.SIRT1,AMPK and p-AMPK m RNA levels for 24 h and 48 h were analyzed by RT-PCR,SIRT1,AMPK and p-AMPK protein expressions in the supernatant at 24 and 48 h was detected by Western blot.RESULTS SRT1720 and AICAR effectively decreased LX-2 cell viabilities and exhibited scarcely little toxicity in human Chang liver cells.SRT1720 and AICAR attenuated collagen-I,α-smooth muscle actin(α-SMA)levels,activated liver kinase B-1(LKB1)and AMPK phosphorylation in ethanol treated LX-2 cells.Meanwhile,SRT1720 and AICAR enhanced SIRT1 expression mediated by ethanol both in Chang liver cells and LX-2 cells.Furthermore,SRT1720 and AICAR suppressed the expression of sterol regulatory element-binding protein-1(SREBP-1)to regulate fatty acid synthesis.CONCLUSION SIRT1 agonist and AMPK agonist blocked the crosstalk between hepatocytes and HSCs via SIRT1/AMPK signaling pathway to modulate hepatocytes accumulation of lipid and HSCs activation.

Distributed Model Predictive Control for Networked Plant-wide Systems With Neighborhood Cooperation

For large-scale networked plant-wide systems composed by physically(or geographically) divided subsystems, only limited information is available for local controllers on account of region and communication restrictions. Concerning the optimal control problem of such subsystems, a neighbor-based distributed model predictive control(NDMPC) strategy is presented to improve the global system performance. In this scheme, the performance index of local subsystems and that of its neighbors are minimized together in the determination of the optimal control input, which makes the local control decision also beneficial to its neighboring subsystems and further contributes to improving the convergence and control performance of overall system.The stability of the closed-loop system is proved. Moreover, the parameter designing method for distributed synthesis is provided.Finally, the simulation results illustrate the main characteristics and effectiveness of the proposed control scheme.

Coking behaviors and kinetics on HZSM-5/SAPO-34 catalysts for conversion of ethanol to propylene

The coke deposition on HZSM-5/SAPO-34 composite catalysts has been studied in the conversion of ethanol to propylene. The HZSM-5/SAPO-34 composite catalysts were synthesized by hydrothermal method（ZS-HS） and fully blending（ZS-MM）. The used catalysts were characterized by XRD, N;adsorption–desorption, TGA, TPO, elemental analysis, FTIR and XPS. The coking kinetics on both ZS-HS and ZS-MM has been investigated and their coking rate equations were obtained. The used ZS-MM catalyst had higher amount of coke and lower nC:nHthan the used ZS-HS. 90% of the coke was deposited in the micropores of ZS-HS, while almost 45% of the coke located in the micropores of ZS-MM. The coke deposited on ZS-HS catalyst was mainly graphite-like carbon species, whereas dehydrogenated coke species was the major on ZS-MM. The coking activation energy of ZS-MM was lower than that of ZS-HS, and the coking rate on ZS-MM was faster than on ZS-HS. In addition, the regeneration of ZS-MM catalyst showed that it had a good hydrothermal stability. The differences on coking behaviors on the two catalysts were due to their different acidic properties and textures.

Mycotoxins in Chinese Traditional Cured Meats: A Review

Chinese cured meats are popular in the world,which are not only meat products but also cultures in China.Fungi can grow on the surface of the traditional cured meats easily during the processing and storage.Some fungi contribute to the specific flavors,color and sensory characteristics of cured meats,while others produce mycotoxins like aflatoxins,ochratoxins,and deoxynivalenol,which will lead to cancer.Although the mycotoxins limits in food have been published by national standard in China,the limits in cured meats are still in blank.Therefore,it is reasonable to identify and reduce the mycotoxins in Chinese cured meats and meat products.This review analyzed the causes of mycotoxins,identification and control methods for Chinese cured meats.

Hepato-protective effect of thymoquinone against acetaminophen induced liver injury is associated with regulation of JNK and AMPK signaling pathway

OBJECTIVE To investigate the hepato-protective mechanism of thymoquinone(TQ) on the development of acetaminophen(APAP)-induced liver injury.METHODS In vivo,male kunming mice were injected with a single dose of 300 mg·kg^(-1) APAP.Some mice were pretreated with TQ(5 or 20 mg·kg^(-1))and N-acetylcysteine(NAC,300 mg·kg^(-1))2 h before APAP injection.Mice were euthanized at 2 h,6 h,12 h after APAP treatment.In vitro,human Chang liver cells were incubated with 3.125,6.25 or 12.5μmol·L^(-1) TQ,10μmol·L^(-1) SP600125 and 500μmol·L^(-1) AICAR in the presence of APAP for 24 h.Cell viability were analyzed by MTT assay,protein expressions were assessed by Western blot.RESULTS TQ pretreatment significantly reduced serum aminotransferase and increased hepatic glutathione(GSH)and glutathione peroxidase(GSH-PX)activities,while significantly inhibited interleukin-1β(IL^(-1)β)levels.TQ significantly inhibited c-Jun N-terminal kinase(JNK),extracellular signal regulated kinase(ERK)and P38 phosphorylation induced by APAP.Moreover,TQ inhibited phosphatidylinositol 3-kinase(PI3K)/mammalian target of rapamycin(m TOR)signaling activation and activated AMPK phosphorylation induced by APAP.In addition,TQ inhibited signal transducer and activator of transcription 3(STAT3)phosphorylation on APAP-induced liver injury.In vitro,APAP enhanced JNK phosphorylation and attenuated AMPK phosphorylation in Chang liver cel s,and these effects were blocked by pretreatment with TQ,SP600125(JNK inhibitor)and AICAR(AMPK activator).CONCLUSION Our findings suggest that TQ may actively prevent APAP-induced liver injury,and this effect may be mediated by JNK and AMPK signaling pathways.

Analysis of Food Safety Supervision and Spot-Check in Sichuan Province in 2019

Through the analysis on 211614 batches of samples from 35 categories of food safety supervision and inspection in Sichuan Province by Administration for Market Regulation of Sichuan Province in 2019,four suggestions were finally put forward.The analysis results showed that in 2019,the overall trend of food safety in Sichuan Province was stable and improved.A total of 30 categories of unqualified samples were detected,and a total of 12135 batches of unqualified samples were detected,with an average sample unqualified rate of 5.73%.Among them,the main problems of unqualified samples were as follows:the use of food additives beyond the scope and limit,accounting for 40.17%of the total number of unqualified samples,microbial contamination in food,accounting for 23.61%of the total unqualified samples,the residue index of agricultural and veterinary drugs in food not meeting the standard,accounting for 15.61%of the total unqualified samples,the quality index in food not meeting the standard,accounting for 8.51%of the total number of unqualified samples,and heavy metals and other pollutants in food exceeding the standard,accounting for 7.10%of the total unqualified samples.

Outdoor Feeding Without Antibiotics,a Better Pattern for the Liver Health of Gushi Chicken

A 180 d feeding trial was conducted to evaluate the effect of different feeding modes on liver of Gushi chicken.The chickens from 1-day-old were fed in the warm house for 30 d,and then divided into four groups by different feeding modes(O-noant,outdoor without antibiotics;O-ant,outdoor with antibiotics;D-noant,indoor without antibiotics;D-ant,indoor with antibiotics),respectively,to evaluate the effect on liver.The results showed that different feeding modes significantly influenced the growth,liver weight,subcutaneous fat thickness,liver fat and liver free amino acid contents.The outdoor feeding without antibiotic reflected remarkably(P﹤0.05)low liver weight and fat content with normal morphology.While,other groups showed different levels of fat metabolism disorder in the liver.Based on chicken liver healthy,the outdoor feeding without antibiotic was the optimal feeding mode for Gushi chicken.

Teaching Reform and Practice of Animal Products Processing under the Background of Intelligent Agriculture

Effective food professional personnel training strategies are explored and implemented,and interdisciplinary talents of food science and engineering in accordance with the background of intelligent agriculture are cultivated from the aspects of construction of teaching staff,reform of teaching content,upgrading of teaching model,construction of industry-education integration platform,which is of great significance to the modernization development of Chinese animal products processing industry.

Durably and intrinsically antibacterial polyamide 6(PA6)via backbone end-capping with high temperature-resistant imidazolium

The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization.Herein,the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imida-zole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6.Then antibacterial PA6(PA6-IL)was synthesized through hydrolyzed ring-opening copolymeriza-tion with imidazolium at the end of the backbones.Compared to physical blending or post-modification methods,antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrin-sic antibacterial activity.As expected,the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days.Additionally,the corresponding electrospun PA6-IL nanofi-brous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity.Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6.The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability.Accordingly,this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers,which can be widely applied in the textiles field.

A graph-based contrastive learning framework for medicare insurance fraud detection

1 Introduction With the improvement of people's living standards,medical insurance has gradually moved towards universal coverage in recent years.Nevertheless,problems such asmedical insurance fraud,resource waste and drug abuse emerge successively,which cause a colossal waste of public resources.Therefore,reducing or eliminating medical insurance fraud can safeguard the medical insurance fund,which is essential for promoting economic development,improving public health,and maintaining social stability[1].The specialized challenges for medical insurance fraud detection are summarized as follows.

Deep learning for change detection in remote sensing:a review

A large number of publications have incorporated deep learning in the process of remote sensing change detection.In these Deep Learning Change Detection(DLCD)publications,deep learning methods have demonstrated their superiority over conventional change detection methods.However,the theoretical underpinnings of why deep learning improves the performance of change detection remain unresolved.As of today,few in-depth reviews have investigated the mechanisms of DLCD.Without such a review,five critical questions remain unclear.Does DLCD provide improved information representation for change detection?If so,how?How to select an appropriate DLCD method and why?How much does each type of change benefits from DLCD in terms of its performance?What are the major limitations of existing DLCD methods and what are the prospects for DLCD?To address these five questions,we reviewed according to the following strategies.We grouped the DLCD information assemblages into the four unique dimensions of remote sensing:spectral,spatial,temporal,and multi-sensor.For the extraction of information in each dimension,the difference between DLCD and conventional change detection methods was compared.We proposed a taxonomy of existing DLCD methods by dividing them into two distinctive pools:separate and coupled models.Their advantages,limitations,applicability,and performance were thoroughly investigated and explicitly presented.We examined the variations in performance between DLCD and conventional change detection.We depicted two limitations of DLCD,i.e.training sample and hardware and software dilemmas.Based on these analyses,we identified directions for future developments.As a result of our review,we found that DLCD’s advantages over conventional change detection can be attributed to three factors:improved information representation;improved change detection methods;and performance enhancements.DLCD has to surpass the limitations with regard to training samples and computing infrastructure.We envision this review can boost developments of deep learning in change detection applications.

儿童眼及视力保健信息化系统的创建与应用

目的：探索儿童眼及视力保健的信息化管理方法，介绍湖州市儿童眼及视力保健信息化系统的创建及应用情况。方法：以《儿童眼及视力保健技术规范》为蓝本，在儿童保健信息管理系统中增加儿童眼及视力保健信息管理模块，并建立数据库，通过市、县、乡三级儿童保健服务网络，实时收集、监测并管理儿童眼及视力保健信息。结果：儿童眼保健信息系统创建后，经在市、县、乡9个适宜技术单位试点应用基础上，逐步以点连线向全市112 个工作站点推广覆盖，录入系统信息4 千条，提高了本地区儿童眼保健服务质量与儿童眼病筛查率，有利于儿童眼保健档案建立，实现对儿童眼病现况的统计、分析。结论：儿童眼及视力保健信息化提高了儿童眼保健管理平，能为决策层决策提供全面的科学依据，是儿童保健事业发展的必然趋势。

An Experimental Study of Text Representation Methods forCross-Site Purchase Preference Prediction Using the Social Text Data

Nowadays, many e-commerce websites allow users to login with their existing social networking accounts. When a new user comes to an e-commerce website, it is interesting to study whether the information from external social media platforms can be utilized to alleviate the cold-start problem. In this paper, we focus on a specific task on cross-site information sharing, i.e., leveraging the text posted by a user on the social media platform (termed as social text) to infer his/her purchase preference of product categories on an e-commerce platform. To solve the task, a key problem is how to effectively represent the social text in a way that its information can be utilized on the e-commerce platform. We study two major kinds of text representation methods for predicting cross-site purchase preference, including shallow textual features and deep textual features learned by deep neural network models. We conduct extensive experiments on a large linked dataset, and our experimental results indicate that it is promising to utilize the social text for predicting purchase preference. Specially, the deep neural network approach has shown a more powerful predictive ability when the number of categories becomes large.

Rare inherited missense variants of POGZ associate with autism risk and disrupt neuronal development

Excess de novo likely gene-disruptive and missense variants within dozens of genes have been identified in autism spectrum disorder(ASD)and other neurodevelopmental disorders.However,many rare inherited missense variants of these high-risk genes have not been thoroughly evaluated.In this study,we analyzed the rare missense variant burden of POGZ in a large cohort of ASD patients from the Autism Clinical and Genetic Resources in China(ACGC)and further dissected the functional effect of diseaseassociated missense variants on neuronal development.Our results showed a significant burden of rare missense variants in ASD patients compared to the control population(P=4.6×10-5,OR=3.96),and missense variants in ASD patients showed more severe predicted functional outcomes than those in controls.Furthermore,by leveraging published large-scale sequencing data of neurodevelopmental disorders(NDDs)and sporadic case reports,we identified 8 de novo missense variants of POGZ in NDD patients.Functional analysis revealed that two inherited,but not de novo,missense variants influenced the cellular localization of POGZ and failed to rescue the defects in neurite and dendritic spine development caused by Pogz knockdown in cultured mouse primary cortical neurons.Significantly,L1CAM,an autism candidate risk gene,is differentially expressed in POGZ deficient cell lines.Reduced expression of L1cam was able to partially rescue the neurite length defects caused by Pogz knockdown.Our study showed the important roles of rare inherited missense variants of POGZ in ASD risk and neuronal development and identified the potential downstream targets of POGZ,which are important for further molecular mechanism studies.