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关键词： carbonyl derivatives   nucleophilic addition  

摘要： The interaction of the monocarbonyl derivative of the closo-decaborate anion [2-B10H9CO](-) with O-nucleophiles has been considered. It has been found that primary, secondary, and tertiary alcohols can enter the addition reaction. It has been shown that the C-O bond is extremely labile in the obtained closo-borate derivatives of the general formula [2-B10H9COOR](2-), and upon heating, its cleavage occurs to form the starting [2-B10H9CO](-). In acidic aqueous solutions, hydrolysis of borylated esters occurs to form a carboxylate derivative of the general formula [2-B10H9COOH](2-). All the derivatives obtained have been isolated and characterized by IR as well as H-1, B-11, and C-13 NMR spectroscopies.

关键词： Heteroproteins   Opposite charges   Technologies   Thermodynamics   Encapsulation  

摘要： Proteins are important components of foods, because they are one of the essential food groups, they have many functional properties that are very useful for modifying the physicochemical and textural properties of processed foods and possess many biological activities that are beneficial to human health. The process of heteroprotein complex coacervation (HPCC) combines two or more proteins through long-range coulombic interaction and specific short-range forces, creating a liquid-liquid colloid, with highly concentrated protein in the droplet phase and much more diluted-protein in the bulk phase. Coacervates possess novel, modifiable, physicochemical characteristics, and often exhibit the combined biological activities of the protein components, which makes them applicable to formulated foods and encapsulation carriers. This review discusses research progress in the field of HPCC in three parts: (1) the basic and innovative experimental methods and simulation tools for understanding the physicochemical behavior of these heteroprotein supramolecular architectures;(2) the influence of environmental factors (pH, mixing ratio, salts, temperature, and formation time) and intrinsic factors (protein modifications, metal-binding, charge anisotropy, and polypeptide designs) on HPCC;(3) the potential applications of HPCC materials, such as encapsulation of nutraceuticals, nanogels, emulsion stabilization, and protein separation. The wide diversity of possible combinations of proteins with different properties, endows HPCC materials with great potential for development into highly-innovation functional food ingredients. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Protein aggregation   Yolk globules   Gelation   LF-NMR   Oil exudation  

摘要： To characterize the process of salting in quail eggs, the effects of different curing times on the physical and chemical properties, texture, and microstructure of the eggs were evaluated using conventional analytical methods. Three different types of protons were found in quail eggs qualitatively analyzed by low-field nuclear magnetic resonance (LF-NMR) and imaging (MRI). With an increase in salting time, the moisture content of the yolks showed a decreasing trend, from 452 to 278 g/kg. The salt content of the egg white increased from 7.2 to 26.9 g/L and from 0.8 to 11.9 g/L in egg yolk. Immersion in NaCl changed the structure of the egg yolk protein and destroyed its thermal stability, as well as increasing oil exudation after heating and the number of granular aggregates in the microstructure of the egg yolk. Scanning electron microscopy (SEM) showed that Na thorn induced the aggregation of egg white protein, which destroyed the three-dimensional network structure of the egg white gel, and gradually caused the aggregation of egg yolk protein. Ultimately, this lead to the solidification of the yolk, which changed the shape of the spherical egg yolk particles, resulting in a gritty texture.

关键词： degree of proton transfer   ionicity   physicochemical properties   protic ionic liquids  

摘要： The physicochemical properties of protic ionic liquids (PILs) determine their industrial applications. In this study, six PILs based on 1-vinylimidazole were synthesized, and their ionicities were determined by(1)H NMR method. The thermodynamic properties, viscosities, densities, and conductivities of these PILs were correlated with the ionicities and the chain lengths of the anions. The ionicity was found to depend on the acidity of the alkyl carboxylic acid. Since HAc has the strongest acidity among these acid precursors, Vim center dot HAc has the highest ionicity and thus the strongest Coulombic interactions among the six PILs. The other five PILs have similar ionicities but different chain lengths in their anions. So, we can separately identify the effects of Coulombic interactions and van der Waals forces on the physicochemical properties of PILs. From these trends, the viscosity and conductivity of PILs may be tuned by varying the acidity and alkyl chain length of the precursors.

关键词： Scaffold   plasma   polypyrrole   poly (glycerol sebacate)   iodine   cellular viability   cytotoxicity assa  

摘要： Polyglycerol sebacate (PGS) scaffolds obtained using a leaching technique were modified with iodine-doped polypyrrole (PPy-I) in a plasma reactor in order to study the effect of exposure time on the cell viability of hDPSCs. SEM analysis showed the formation and growth of PPy-I particles as the exposure time was increased, while FTIR and XPS analysis revealed the presence of -NH- and N+ groups in the chemical composition of the surfaces, relating to the increase in the amount of PPY-I particles. The water contact angle measurements showed an increase in the scaffold's hydrophilicity with greater exposure times which was also attributed to the rising of PPy-I particles. It was also observed that PPy-I promotes the rigidity of the treated PGS scaffolds. when in direct contact with treated PGS scaffolds, cell viability improved with respect to non-treated scaffolds, however only at shorter time exposures. Extracts of plasma-treated PGS scaffolds showed high cytotoxicity as the time exposure to plasma treatment was increased.

关键词： Land use   Fertility   Penetration resistance   Secondary forest  

摘要： In Brazil, the productive and sustainable use of Amazonian soils under agroforestry systems (AFS) has been considered a research challenge. This study aimed to evaluate the physicochemical attributes of a soil under AFS, comparing it with the soil under an adjacent secondary forest (SF). The study was carried out in an AFS area cultivated with passion fruit (Passiflora edulis), cupuacu (Theobroma grandiflorum) and Brazilian mahogany (Swietenia macrophylla), between 2005 and 2019. Both study areas (AFS and SF) were divided into five blocks. Sampling was carried out in two soil depths (0-20 cm and 20-40 cm), which was subjected to chemical analysis to determine the pH in water, contents of macro- and micronutrients, exchangeable bases, exchangeable aluminum, base saturation, cation exchange capacity and organic matter contents. As for the physical attributes, penetration resistance (PR) up to 40 cm deep in the soil was evaluated, using 50 randomized measurement per study area. The contents of macronutrients were higher in AFS, and the content of organic matter was higher in SF. The contents of micronutrients did not follow a specific pattern, and presented a similar distribution in both environments. The PR was higher in SF, showing a linear behavior that increases with increasing depths, while in AFS, there was a stabilization tendency within soil depth. Soil fertility was better in AFS, mainly due to the residual contents of periodic fertilization, in addition to presenting better conditions for root establishment.

关键词： bacterial community   conservation tillage   growth stage   soil properties   soil quality  

摘要： Conservation tillage is an alternative to conventional tillage (CT) for addressing the issue of soil degradation, while how it affects soil quality remains unclear. To characterise the temporary and stable effects of 8 years of conservation tillage on soil quality, topsoil (0-20 cm) properties, 16S rDNA-based bacterial community properties and their relationships were analysed. Three tillage practices (CT [as the control], subsoiling tillage [ST] and no tillage [NT]) were compared at the sowing and harvest stages of a continuous winter wheat (Triticum aestivum L.) system. The mean weight diameter of the water-stable aggregate, organic matter, total N/P/K and available K consistently improved with NT at both crop stages, with averages of 26.8, 35.3, 38.5, 29.2, 13.1 and 59.1%, respectively. Similar but lower levels of improvements were observed under ST. Tillage did not significantly affect soil bulk density, penetration resistance and temperature, whereas NT significantly decreased capillary porosity by 7.9% at sowing. At the sowing stage, CT showed higher bacterial alpha/beta-diversity but lower soil water content and abundances of N-cycling bacteria. The physicochemical properties showed significant correlation with the abundances of some genera belonging to Proteobacteria, Nitrospirae and Actinobacteria. After 8 years of experimentation, we found that conservation tillage, especially NT, resulted in stable effects on soil aggregation and nutrient storage. Although soil compaction temporarily decreased after CT, the bacterial community, soil water storage and the aforementioned stable effects were more favourable for soil sustainability under conservation tillage.

关键词： Hizikia fusiformepolysaccharide   structural characterization   hypoglycemic activity   molecular mechanism  

摘要： In the current study, a functional polysaccharide fraction (HFP) was obtained fromHizikia fusiformeby ultrasound-assisted enzymatic extraction, and its structural characterization and hypoglycemic activity and potential molecular mechanism were investigated. The results indicated that HFP with high uronic acid was a heterogeneous polysaccharide composed of six monosaccharides. Congo red test explained that HFP had no triple helix conformation. AFM analysis revealed that HFP was spherical particle with flame-like aggregates and multiple strands closely arranged. Rheological analysis showed that HFP exhibited shear-thinning flow behavior. HFP significantly ameliorated diabetes-related symptoms and serum profiles and increased muscle glycogen storage in rats. HFP administration at 400 mg/kg body weight/day displayed greater advantages than metformin in controlling the levels of fasting blood glucose, triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bile acid (TBA) of diabetic rats. Intervention of HFP up-regulated markedly the expression of AMPK-alpha, GLUT4, PI3K and Akt in skeletal muscle of diabetic rats at the mRNA and protein levels, revealing hypoglycemic effects of HFP may be related closely to improving insulin resistance and mitochondrial function of skeletal muscle.

关键词： Cricket   Killing method   Nutritional composition   Digestibility   Oxidation   Storage stability  

摘要： The present research studied the effect of different killing methods on various quality attributes of the house cricket (Acheta domesticus) powder: physicochemical traits (pH, colour, radical scavenging activity, browning index, protein oxidation), nutritional profile (proximate composition), in vitro human digestibility, and oxidative stability of lipids during storage. With this purpose, seven different killing methods were compared: blanching (40 s at 100 degrees C), steaming (2 min 15 s), freezing (2 h 10 min at -20 degrees C), carbon dioxide (2 h 7 min at 25 degrees C), vacuum (1 h 35 min at 25 degrees C), plastic bag (3 h 1 min at 25 degrees C), and carbon dioxide + blanching (40 min carbon dioxide at 25 degrees C + 40 s blanching). All killing methods reduced the radical scavenging activity (p < 0.001) and increased the browning index (p < 0.001) of the cricket powder. Overall, cricket powder obtained through carbon dioxide, vacuum and plastic bag killing methods provided the best proximate composition (p < 0.001). Freezing, carbon dioxide, vacuum and plastic bag provided cricket powder with the highest polyunsaturated fatty acids proportion, thus having the healthiest lipid profile (p < 0.001), and guaranteed the lowest oxidative degree of lipids (p < 0.001). In the same groups, however, the lowest in vitro human digestibility was also observed (p < 0.001). Overall, none of the tested methods had detrimental effects on product quality and, at present, the choice of the most appropriate killing strategy seems a matter of equipment availability and cost-efficiency evaluations. Industrial relevance: The present study provides new insights on the impact of the killing method on the final quality of cricket powder, a versatile, nutrient-rich food. The choice of the most appropriate method, together with its industrial implementation, are fundamental aspects to guarantee satisfactory quality standards and consumer's health.

关键词： Alzheimer's disease   HPLC   log Pdetermination   method validation   pK(a)determination   tacrine  

摘要： Tacrine derivatives containing iodobenzoic acid were developed as a novel multitarget-directed ligand and find potential application in the treatment of Alzheimer's disease. The aim of this study is to perform a physicochemical profile of this series. Experimental log Pand pK(a)values were determined and compared with those already calculated. The results indicated better values of the tested compounds than the values predicted using computer software. The stability report was obtained using the developed HPLC method. The stability assay in different environment conditions provided information about the photosensitivity of these compounds and a proper method for the storage of this series of compounds.