Experiences on education of students and professionals in thermal process safety

The number of incidents due to reactive hazards demonstrate the need of training for professionals and for students in the field of Thermal Process Safety. The specific difficulty in this field is that the assessment of thermal risks requires knowledge in physical chemistry as well as engineering knowledge. Hence, in order to teach this knowledge, it must first be simplified. The strongly non-linear behaviour of reactors in runaway situations also requires specific teaching methods. Different didactic tools are presented: case histories, numerical simulation, building a tool box (MS-Excel), E-Learning, Thermal Process Safety App, role game with a virtual laboratory are presented. The text concludes with some considerations on teaching professionals in the industry and students in universities.     

基于乙酰胆碱酯酶和氧化应激研究海胆酮对阿尔茨海默症的作用机制

海胆酮是一种酮式类胡萝卜素，主要从海胆及藻类等海洋生物中提取。本文研究海胆酮对乙酰胆碱酯酶（acetylcholinesterase，AChE）的抑制作用，应用酶动力学、荧光光谱、圆二色光谱和分子对接技术研究海胆酮对AChE的抑制机理，并用淀粉样β蛋白片段25～35（amyloid beta-peptide 25-35，Aβ25-35）诱导大鼠肾上腺嗜铬细胞瘤细胞（PC12细胞）建立阿尔茨海默症（Alzheimer’s disease，AD）模型，研究海胆酮对AD细胞模型氧化应激损伤的作用。结果表明，海胆酮有很强的AChE抑制活性，其半抑制质量浓度为（16.29±0.97）μg/mL，抑制常数Ki为3.82 μg/mL，表现为竞争性抑制；海胆酮可诱导AChE二级结构改变，更容易与AChE活性中心氨基酸Ser200、His440、Trp84和Tyr121结合，阻碍底物碘代硫代乙酰胆碱（acetylthiocholine iodide，ATCI）与酶结合，从而引起酶活力降低。海胆酮能有效抑制Aβ25-35诱导PC12细胞的AChE活力，降低丙二醛含量，增加超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活力，减轻Aβ25-35诱导的PC12细胞氧化应激损伤。本研究基于AChE和氧化应激阐明了海胆酮对AD的潜在作用机制，为海胆酮在功能食品、生物医药等领域的应用提供了数据支持和理论根据。     

New insights into the thermodynamics and kinetics of triacylglycerols crystallization

Understanding the transition from an isotropic liquid state to an organized crystalline state of triacylglycerols has great significance when designing lipid-based materials in general and food products in particular. In the current research, the balance between the demand for the tuning-fork (Tf) conformation, which is the suitable conformation for most crystalline organizations, and the supply of these molecules was discussed. Based on the negative dependency of the nucleation rates and the induction times on temperature, it was suggested that the limiting factor for the nucleation process is the conversion from the Tf conformation to any other conformation. On the other hand, based on the positive dependency of the melting temperatures and enthalpies on crystallization temperature, and the organized morphologies obtained at higher temperatures, it was suggested that the limiting factor during the crystal growth process is the conversion to the Tf conformation from another conformation.     

Inactivation efficacy of combination treatment of blue light-emitting diodes (LEDs) and riboflavin to control E. coli O157:H7 and S. Typhimurium in apple juice

In the present study, we assessed the bactericidal effect of a combination of blue light (BL) and riboflavin (Rb) and elucidated the bacterial inactivation mechanism. Higher Rb concentrations (0.005–50 μM) resulted in greater inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium suspended in phosphate buffer saline (PBS). In the present dose-dependent study, significant inactivation was observed following BL + Rb treatment at 30 J/cm² (19 min 23 s) in PBS. In apple juice (pH 3.2), BL + Rb treatment resulted in a 3–4-log reduction in the pathogens at 30 J/cm². As expected, ROS was the key factor for pathogen inactivation. Moreover, cell membrane damage was observed on propidium iodide (PI) uptake analysis and transmission electron microscopy (TEM). These results indicated that BL + Rb treatment can be used as a powerful intervention system to ensure microbial safety in liquid beverages, in addition to enhancing the nutritional value.     

Whey protein based electrosprayed nanospheres for encapsulation and controlled release of bioactive compounds from Tinospora cordifolia extract

The synergistic effects of bioactive compounds of Tinospora cordifolia have insulin mimicking and hypoglycemic activity, however, low bioavailability and poor stability limits its potential. In the present study, an appropriate delivery system was developed for the controlled release of its anti-diabetic activity. The bioactive compounds such as palmatine, berberine and palmatoside had better binding energy as observed in docking studies compared to that of the commercial active compounds. However, as these biocompounds from Tinospora cordifolia are associated with low stability and poor bioavailability, these compounds were encapsulated in a core-shell matrix of whey protein isolate. The bioactive compounds had highest antidiabetic activity in chloroform extract with an IC₅₀ concentration of 11.34 mg/ml. An increase in 28.12% activity was observed in nanoemulsion form with an average size of 82.68 ± 4.37 nm. The bioactive compounds were further encapsulated by electrospray technique for increased stability. The particles had an encapsulation efficiency of 91.2 ± 3.27% with an average particle size of 187 ± 2.71 nm. The kinetic study revealed the complete release of bioactive compounds after 24 h of incubation in buffer solution. This formulation can be further explored as novel nutraceutical delivery system with minimal side effects as compared to their synthetic counterparts. Considering the potential application of this developed technology, further upscaling as well as in-vivo experimentation on small as well as large animals should be performed.     

3D printing and controlled release of functional ripening surimi improved by nano starch-xylo-oligosaccharides: Chemical bonds and microstructure influences

To solve the problem of fast release, unsustainability of functional compounds in 3D printed surimi, nano scale of rice starch-xylo-oligosaccharides (XOS) was prepared. Meanwhile, its characteristics and printing effects on surimi were determined. Results shown that the nano rice starch and XOS with ratio of 1:2.5 had good characteristics (particle size 444 nm, embedding rate 86%, stable particle size with Na⁺ and heating process). Moreover, it endowed surimi with antioxidant ability and prolonged the release of XOS in surimi during in vitro digestion, which might keep it for continuous release. Additionally, nano starch-XOS increased ionic bonds and hydrogen bonds by 78% and 58% respectively to enhance gel strength, texture of surimi. As well as it also could fill up gel network gaps to form denser structure, which increased self-supporting ability to improve printing effects. While excessive XOS (>1%) could wrap protein to inhibit gel formation to produce burs and pores of printed surimi-XOS, leading to the pores enlargement and collapse due to the enhancement of hydrophobic force and disulfide bonds after ripening. However, nano starch could aggregate XOS to delay the occurrence of collapse (>2% XOS content). Thus, nano starch-XOS could promote the application of functional surimi in 3D printing.     

Differential gene expression of the healthy conjunctiva during the day

PurposeTo determine if there is diurnal variation in gene expression in normal healthy conjunctival cells.MethodsBulbar conjunctival swab samples were collected from four healthy subjects in the morning and evening of the same day. The two swab samples were taken from one eye of each participant, with a minimum of five hours gap between the two samples. RNA was extracted and analysed using RNA sequencing (RNA-Seq).ResultsA total of 121 genes were differentially expressed between the morning and the evening conjunctival samples, of which 94 genes were upregulated in the morning, and 27 genes were upregulated in the evening. Many of the genes that were upregulated in the morning were involved in defence, cell turnover and regulation of gene expression, while the genes upregulated in the evening were involved in signalling and mucin production.ConclusionsThis study has identified several genes whose expression changes over the course of the day. Knowledge of diurnal variations of conjunctival gene expression provides an insight into the regulatory status of the healthy eye and provides a baseline for examining changes during ocular surface disease.     

Mapping haze-komi on rice koji grains using β-glucuronidase expressing Aspergillus oryzae and mass spectrometry imaging

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Determination of Metastable Zone Width and Nucleation Induction Period of Palm Oil and its Olein/Stearin in Melting Layer Crystallization

Measurement methods of metastable zone width (MZW) and nucleation induction time for melting layer crystallization of palm oil (PO) and its olein/stearin (POL/PST) were established, and the effects of cooling rate (corresponding to various supercoolings) on MZWs and induction time for melting layer crystallization of PO, POL, and PST were determined. The results indicated that the MZW coherently rose with increasing cooling rates with respect to PO and POL, while it declined with higher cooling rates for PST. The induction period results demonstrated that the nucleation induction periods of PO, PST, and POL decreased with increasing supercoolings, and the lag time for nucleation negatively correlated to the melting point of oils at the same supercooling. These data could offer significant instruction in designing and controlling the melting layer crystallization process for palm oil.