Changes in physicochemical properties and myofibrillar protein properties in grass carp salted by brining and injection

The aim of this study was to investigate the changes in physicochemical properties and myofibrillar protein properties of grass carp meat during brining and brine injection at 4 °C. The time reached equilibrium was 7 h in brining group and 5 h by injection, where the salt content was about 1.76%. The water content, water holding capacity and yield in injection group (86.59%, 9.18% and 110%, respectively) were higher than brining group (84.76%, 11.47%, and 108%, respectively) at equilibrium point significantly (P < 0.05). This was attributed to the more swollen filament lattices and disordered protein structure in injection group (P < 0.05). The myofibrillar protein structure was compared, including sulphydryl content, surface hydrophobicity, solubility, sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern and secondary structure. The injection group presented the better quality of salted fish meat in shorter time.     

天然气门站汇管管理的相关规范分析探讨

汇管作为天然气行业常见设备,其应遵循的规范在历史上一直存在争议.本文从国家规范中,对天然气站场汇管相关规范的使用范围、差异等内容进行了比较分析,有助于城镇燃气管理人员从设计和使用管理方面进一步厘清规范内容.同时,本文为规范的修订提出了建议.     

Food-grade carrageenans and their implications in health and disease

Food additives, often used to guarantee the texture, shelf-life, taste, and appearance of processed foods, have gained widespread attention due to their increased link to the growing incidence of chronic diseases. As one of the most common additives, carrageenans have been used in human diets for hundreds of years. While classified as generally recognized as safe (GRAS) for human consumption, numerous studies since the 1980s have suggested that carrageenans, particularly those with random coil conformations, may have adverse effects on gastrointestinal health, including aggravating intestinal inflammation. While these studies have provided some evidence of adverse effects, the topic is still controversial. Some have suggested that the negative consequence of the consumption of carrageenans may be structure dependent. Furthermore, pre-existing conditions may predispose individuals to varied outcomes of carrageenan intake. In this review, structure–function relationships of various carrageenans in the context of food safety are discussed. We reviewed the molecular mechanisms by which carrageenans exert their biological effects. We summarized the findings associated with carrageenan intake in animal models and clinical trials. Moreover, we examined the interactions between carrageenans and the gut microbiome in the pathogenesis of gastrointestinal disorders. This review argues for personalized guidance on carrageenan intake based on individuals’ health status. Future research efforts that aim to close the knowledge gap on the effect of low-dose and chronic carrageenan intake as well as interactions among food additives should be conducive to the improved safety profile of carrageenans in processed food products.     

HVOF制备MCrAlY涂层过程中WC杂质颗粒的演变遗传行为研究

在热喷涂工业生产过程中,喷涂制备不同材料体系的涂层之前需要对送粉路径(送粉罐、送粉盘、搅拌器、送粉管路、送粉针)进行清理,但由于送粉路径内部结构复杂且存在静电吸附效应,使得残留于喷涂系统的粉末无法被完全去除,通常以微量杂质颗粒的形式被带入新涂层,进而影响新涂层的性能。为此,本文研究了在单晶基材表面采用高速火焰(HVOF)喷涂制备MCrAlY涂层过程中,送粉路径残留的WC杂质颗粒(WC-10Co4Cr)在涂层及涂层与基材界面处的遗传演变行为,分别采用SEM、EDS分析了WC杂质在喷涂态、热处理态涂层中的微观组织和相组成。研究结果表明,WC杂质颗粒确实存在于MCrAlY涂层中,并在后期热处理及氧化试验中进一步分解而固溶于涂层中,甚至扩散至单晶基材内部引起含W碳化物的生成,影响涂层及单晶基材的显微组织,改变局部的成分均匀性。同时,本文还采用ThermoCalc软件进行了热力学计算模拟,辅助分析了WC分解及W与C元素在显微组织中的遗传特性。对于WC类粉末和MCrAlY粉末共用的HVOF喷涂设备,建议给MCrAlY粉末配备单独的送粉路径,以确保涂层的纯净度与质量。     

Microstructure and mechanical properties of Mg-5Li-1Al sheets prepared by accumulative roll bonding

Ultrafine-grain and high-strength Mg-5Li-1Al sheets were prepared by accumulative roll bonding (ARB) process. Evolution of microstructure and mechanical properties of ARB-processed Mg-5Li-1Al sheets was investigated.Results show that, during ARB process, the evolution of deformation mechanism of t Mg-5Li-1Al alloy is as follows: twinning deformation, shear deformation, forming macro shear zone, and finally dynamic recrystallization (DRX). The grain refining mechanism changes from twin DRX to rotation DRX. With the increase in ARB cycles, strength of the Mg-5Li-1Al sheets is enhanced, whilst elongation varies slightly. With the increase in rolling cycles, anisotropy of mechanical properties decreases. It is conclusive that strain hardening and grain refinement dominate the strengthening mechanism of Mg-5Li-1Al alloy.     

羊场湾煤矿软岩底板炉渣混凝土加固技术

为提高软岩底板强度而供无轨胶轮车等大型车辆行驶，结合羊场湾煤矿16206机巷软岩底板地质条件，研究了炉渣混凝土底板加固技术，确定了合理的配比方案，并对机巷现场进行混凝土地坪铺设应用。研究与应用结果表明：炉渣混凝土底板强度可满足大型车辆连续运输所需，极大地提高了底板承载能力，防止底鼓，为长距离巷道实现连续运输提供了基础保障。     

龙滩坝8#采场地压监测与结果分析

为掌握龙滩坝8#采场矿体在开采过程中地压的变化规律，在结合现场实际情况的同时，根据开挖揭露的地质条件，采用钻孔应力计、锚杆应力计、收敛计、多点位移计和声发射对采场矿柱、顶板及巷道变形情况进行监测，得到回采过程中矿柱、顶板、巷道的受力状况。掌握采场地压的变化规律，为矿体的开采设计提供参考。     

Fluoro-Photoacoustic Polymeric Renal Reporter for Real-Time Dual Imaging of Acute Kidney Injury

Photoacoustic (PA) imaging agents detect disease tissues and biomarkers with increased penetration depth and enhanced spatial resolution relative to traditional optical imaging, and thus hold great promise for clinical applications. However, existing PA imaging agents often encounter the issues of slow body excretion and low-signal specificity, which compromise their capability for in vivo detection. Herein, a fluoro-photoacoustic polymeric renal reporter (FPRR) is synthesized for real-time imaging of drug-induced acute kidney injury (AKI). FPRR simultaneously turns on both near-infrared fluorescence (NIRF) and PA signals in response to an AKI biomarker (γ-glutamyl transferase) with high sensitivity and specificity. In association with its high renal clearance efficiency (78% at 24 h post-injection), FPRR can detect cisplatin-induced AKI at 24 h post-drug treatment through both real-time imaging and optical urinalysis, which is 48 h earlier than serum biomarker elevation and histological changes. More importantly, the deep-tissue penetration capability of PA imaging results in a signal-to-background ratio that is 2.3-fold higher than NIRF imaging. Thus, the study not only demonstrates the first activatable PA probe for real-time sensitive imaging of kidney function at molecular level, but also highlights the polymeric probe structure with high renal clearance.