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关键词： Compost   Feedstock   Organic waste   Humic substances   Soil amendment   Vermicompost  

摘要： Composting and vermicomposting have attracted attention in relation to both waste management and the potential to produce organic amendments that could improve soil quality. The main differences between compost depend on the feedstock, the production process, and the degree of maturity. In the present study, samples of compost of different origin (food and green waste, livestock waste, algae waste, urban waste or sewage sludge) or subjected to different composting methods (traditional or using earthworms) were collected for analysis. Additionally, samples collected at various stages of the composting process were compared (raw material, 15 and 30 days of composting, and final compost). Different analysis and techniques were used to establish the chemical composition, physicochemical and acid-base properties of compost samples and the organic matter extracts. The correlations obtained (between the abundance of acid groups in different extracts of the compost or between the cation exchange capacity and the C/N atomic ratio) would allow for predicting the compost behaviour based on certain characteristics, and a reduction in the number of parameters determined experimentally, thus facilitating comparisons between different compost. In addition, the potential value of the compost as amendment was tested with a Haplic Cambisol from a mining area. The application of compost increased the pH, the organic matter and nutrient content, and promoted seed germination and root growth.

关键词： Biodegradable film   Active packaging   Total phenolic content   Antioxidant activity   Raisin  

摘要： The objective of this study was to evaluate the application of a biodegradable film, based on grape seed flour extract, for raisin packaging. Physico-chemical characteristics (moisture, total soluble solids, total acidity, pH), total phenolic content and antioxidant activity were evaluated during 182 days of storage at 20 degrees C, compared to a poly(ethylene) film packaging. After 182 days, the use of biodegradable film increased raisin moisture and pH, decreased total soluble solids and total acidity of raisin compared to the use of poly(ethylene) film. The total phenolic content and antioxidant activity of raisin packed in the biodegradable film were 60.0 and 51.8% higher, respectively, than in poly(ethylene) film. The results showed that the biodegradable film based on seed flour extract is a potential material for active packaging due its contribution to the maintenance of the antioxidant activity of raisin and can be used for their conservation.

关键词： Bone repair   beta-SiAlON ceramics   Osteogenesis   Silicon nitride  

摘要： This study evaluated the effects of different Z-values on the physical, chemical, and biological properties of beta-SiAlON ceramics. Increasing the Z-value of the beta-Si3N4 solid solution's main phase resulted in the replacement of Si-N bonds with Al-O bonds. The number of columnar crystals decreased, bulk density increased, and porosity decreased, thus transforming the fine-particle microstructure of beta-Si3N4 into the columnar structure of beta-SiAlON. The compressive strength increased, which facilitated sintering at 1500 degrees C without sintering auxiliaries. H+ and OH- ions in deionized water broke the covalent bonds on the beta-SiAlON surface, thereby forming new Si-OH, Al-OH, and N-H bonds on the beta-SiAlON surface and producing SiO44-, AlO2-, and NH4+ groups in the solution. Increasing the soaking time changed the compositions of ionized H+ and OH- ions, thus increasing the pH. MC3T3-E1 cells were cultured on the beta-SiAlON surface, and it was observed that the increase in the Z-value of beta-SiAlON had no influence on cell adhesion and spreading, but it may slightly suppress cell proliferation at high Z-values. At low Z-values, the low AlO2- concentration helps promote osteogenic differentiation and mineralized nodule formation. Thus, beta-SiAlON ceramics possess excellent physical, chemical, and biological properties and are considered excellent bone-repairing materials.

关键词： Acidic soils   Nutrient imbalance   Lime   Magnesium fertilizer   Pomelo quality  

摘要： Magnesium (Mg) is an essential mineral nutrient for plant growth, and its deficiency in citrus orchards has been widely observed in the acidic soils of southern China. Lime amendments have been proposed as potential solution to mitigate the soil pH and improve the soil quality. Therefore, we evaluated the effects of lime and Mg fertilizer on soil physicochemical properties, nutrients uptake, pomelo quality and yield, and economic benefits in the pomelo production area. For this, a field experiment was conducted during 2017-2019 using three treatment combinations;(i) control with no lime and Mg fertilizer (CK), (ii) Mg fertilizer with no lime (+Mg), and (iii) lime combined with Mg fertilizer (Lime+Mg). We found that Lime+Mg treatment significantly increased pomelo yield by 34.2% and 26.8% in 2018 and 2019, respectively over CK. Economically, Lime+Mg application increased the annual net income by 37.4%. Under Lime+Mg treatment, the concentration of N, K, Ca, and Mg was increased, while Fe and Mn decreased in leaf, peel, and pulp. Lime+Mg application significantly increased the edible rate, and total soluble solids (TSS) by 7.2% and 4.2%, respectively, while decreased the titratable acid (TA) by 11.7% in pomelo. Lime+Mg treatment also raised the soil pH, available N, P, Ca, and Mg concentrations significantly. Our results demonstrate that Lime+Mg incorporation to acidic soils of pomelo orchard alleviates the soil acidification, improves the nutrients availability, yield and fruit quality, and results in more economic benefits.

关键词： Amphibians   Biomarkers   Toxicity bioassays   Water quality  

摘要： Traditionally, water quality was assessed by physicochemical parameters. However, a more comprehensive analysis is needed to study the effects of polluted water bodies on key species over time. So, the aim of this study was to monitor through physicochemical and ecotoxicological indicators the surface water quality of four study sites with different land uses from the lower Parana river basin (Argentina) during spring and summer of two years: Morejon stream (S1), De la Cruz stream upstream (S2), downstream (S3) and Arrecifes river (S4). Physicochemical parameters were measured in situ and in laboratory, and a Water Quality Index (WQI) was calculated. Chronic toxicity bioassays were performed with surface water samples using Rhinella arenarum embryos and larvae. Also, oxidative stress (catalase, superoxide dismutase, glutathione S-transferase, reduced glutathione and lipid peroxidation), neurotoxicity (butyrylcholinesterase) and genotoxicity (micronuclei frequency) biomarkers were measured at acute exposure, and an Integrated Biomarkers Response (IBR) index was calculated. The water quality varied between excellent and bad in S1, good and bad in S2 and S3, and bad and marginal in S4. S1 presented the greatest variability of pesticides and S4 the highest number of metals exceeding the limits for the local protection of aquatic life. Mainly, S4 caused lethality in R. arenarum larvae, reaching a maximum mortality of 83.3% at 504 h of exposure. The lethal toxicity of S1 and S2 varied between periods. Water samples from all sites altered the oxidative stress, neurotoxicity and genotoxicity biomarkers, and the IBR was negatively correlated with the WQI. The IBR reflected the effects of the degraded water quality on the exposed organisms. So, the importance of evaluating both physicochemical and ecotoxicological parameters to analyze integrally the water quality of polluted areas is highlighted. A degradation of the studied water bodies and its negative impact to the native

关键词： Exopolysaccharide   Levan   Bacillus sp   Structure   Function   Rheology  

摘要： An exopolysaccharide, EPS-B108, was isolated from the fermented broth (with a yield of 11.3 g/L) of halotolerant Bacillus sp. SCU-E108 by ethanol precipitation, anion-exchange and gel-filtration chromatography, and well characterized by means of physical, chemical and spectral techniques. Data indicated that EPS-B108 was composed solely of fructose with a high molecular weight of 3.578 x 107 g/mol, and contained a 13-(2 -+ 6)linked D-Fruf backbone with a single 13-D-Fruf at C-1 position. An irregular saccular- or cake-like shape was observed under the enlarged view. It showed no acute oral toxicity in mice, and had good thermal stability (242 degrees C), solubility in water (91.3%) and oil-holding capacity (1717.0%). Steady-shear flow and dynamical viscoelasticity of aqueous EPS-B108 solutions varied with the polymer concentration, shear rate and temperature, and were described by the Power-law model. Together, these findings support the further application of EPS-B108 as an alternative source of functional food additives and ingredients.

关键词： Upper-Division Undergraduate   Physical Chemistry   Computational Chemistry   Equilibrium   Spectroscopy   Thermodynamics   Computer-Based Learning   Internet   Web-Based Learning  

摘要： The COVID-19 pandemic has led to an increasing amount of research on redesigning educational models. This paper describes the contents of a new laboratory course on physical chemistry based on blended learning, designed for third-year students in the Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University. We provided students with digest video materials for flipped learning, a cloud computing environment, and video conferencing tools. These materials enhanced the course contents to facilitate effective education during the pandemic. The results of a questionnaire survey showed that students were delighted with the new course, which comprehensively included experiments, computation, and data science.

关键词： biopolymers   doubly layered W   O   W nanoemulsions   borage seed oil  

摘要： Borage seed oil (BSO), peppermint oil (PO) and lycopene (LC) have accomplished a lot of interest due to their therapeutic benefits in the food and pharmaceutical sectors. However, their employment in functional food products and dietary supplements is still precluded by their high susceptibility to oxidation. Thus, the encapsulation can be applied as a promising strategy to overcome these limits. In the present study, doubly layered water/oil/water (W/O/W) nanoemulsions were equipped using purity gum ultra (PGU), soy protein isolate (SPI), pectin (PC), whey protein isolate (WPI) and WPI-PC and SPI-PC complexes, and their physico-chemical properties were investigated. Our aim was to investigate the influence of natural biopolymers as stabilizers on the physicochemical properties of nanoemulsified BSO, PO and lycopene thru W/O/W emulsions. The droplet size of the fabricated emulsions coated with PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 156.2, 265.9, 254.7, 168.5, 559.5 and 656.1 nm, correspondingly. The encapsulation efficiency of the entrapped bioactives for powders embedded by PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 95.21%, 94.67%, 97.24%, 92.19%, 90.07% and 92.34%, respectively. In addition, peroxide and p-anisidine values were used to measure the antioxidant potential of the entrapped bioactive compounds during storage, which was compared to synthetic antioxidant and bare natural antioxidant. The collected findings revealed that oxidation occurred in oils encompassing entrapped bioactive compounds, but at a lower extent than for non-encapsulated bioactives. In summary, the findings obtained from current research prove that the nanoencapsulation of BSO surrounded by innermost aqueous stage of W/O/W improved its stability as well as allowed a controlled release of the entrapped bioactives. Thus, the obtained BSO-PO-based systems could be successfully used for further fortification of food-stuffs.

关键词： Different alcohols-diesel fuels   Morphology   Nanostructure   Oxygenated functional groups  

摘要： Particle is the main pollutant in diesel engine exhaust, which seriously endangers human health and the atmo-spheric environment. The use of alcohol fuels in diesel engines can effectively reduce particle emissions, but alcohol fuels with different carbon chain lengths will affect the generation process of particles, which in turn changes the physicochemical properties and oxidation characteristics of the particles. Therefore, it is particularly important to study the properties of particle emitted by diesel engines fueling alcohol fuels with different carbon chain lengths. The physicochemical properties of soot emitted from commercial diesel engines were studied by thermogravimetric analyzer, HRTEM (high-resolution transmission electron microscopy), and XPS (X-ray photoelectron spectroscopy) in this paper, respectively. The diesel engine used alcohol-diesel blends of different carbon chain lengths with the same oxygen content as fuels, such as methanol/diesel blend (M10), n-butanol/diesel blend (NB25), and n-octanol/diesel blend (NO45), and pure diesel fuel was used as a reference. The results showed that the use of alco-hols reduced the fractal dimension (Df) of particles, and the NB25 particles had the smallest Df. Moreover, the par-ticles of blended fuels had smaller primary particle diameter (dp) compared to pure diesel. However, with the use of short-chain to long-chain alcohols, an increasing tendency of dp was observed. In terms of the nanostructure, as the use of short-chain to long-chain alcohols, the La (fringe length) increased, both the d (fringe separation distance) and Tf (fringe tortuosity) reduced, which was not favorable for the oxidation of the particles. In addition, in terms of ox-ygenated surface functional groups (SFGs), the C=O group occupied a higher proportion in most working conditions relative to the groups of C\\O and COO. Further analysis showed that the dp and nanostructure had more influence on the oxidation behavior of soot than Df a

关键词： Chitosan   Sulfated chitosan   Sulfamic acid   Density functional theory  

摘要： Chitosan is an important biologically active amino polysaccharide. Water-soluble sulfated chitosan deriva-tives are widely used as anticoagulant and antiviral drugs. In this study, new methods for sulfamic acid sulfation of chitosan in the presence of urea in 1,4-dioxane and in a deep eutectic solvent representing a mixture of sulfamic acid and urea have been proposed. Mathematical models of sulfation of chitosan in these systems have been built. The obtained sulfated chitosan derivatives have been investigated by Fourier-transform infrared spectroscopy, X-ray diffractometry, atomic force microscopy, gel permeation chromatography, elemental analysis, and the density functional theory. The introduction of the sulfate group into the chitosan molecule was proven by infrared spectroscopy. When using the sulfamic acid/urea mixture, side reactions of carbamation of chitosan have been observed. It has been established from the atomic force microscopy data that the sulfated chitosan film surface consists of spherical particles par-tially agglomerated with each other. According to the gel permeation chromatography data, sulfated chi-tosan obtained in different systems, but under the same conditions (temperature and time), has different molecular weight distributions. The molecular weight distribution curve of the sulfated chitosan obtained in the sulfamic acid-urea-1,4-dioxane system is significantly shifted to the high-molecular region (Mw -36.6 kDa), while the sulfated chitosan obtained in the sulfamic acid/urea deep eutectic solvent (Mw -27.2 kDa). The density functional theory calculation of chitosan sulfates in the B3LYP/6-31G(d, p) basis set have been made. (c) 2021 Elsevier B.V. All rights reserved.