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Alcohol groups and β-O-4 (C-C) linkages are widespread in biomass feedstock that are abundant renewable resource for value-added chemicals. The development of sustainable protocols for direct oxidation or oxidative cleavage of feedstock materials in a controlled fashion, using open air as an oxidant is an intellectually stimulating task to produce industrially important value-added carbonyls. Further, the oxidative depolymerization of lignin into fine chemicals has evoked interest in recent times. Herein, we report the first example of a catalyst system that could activate molecular oxygen from atmospheric air for controlled oxidation and oxidative cleavage/depolymerization of feedstock materials such as alcohols, β-O-4 (C-C) linkages and real lignin in water under open air conditions. The selectivity of carbonyl products is controlled by altering the pH between ~7.0 and ~12.0. The current strategy highlights the non-involvement of any external co-catalyst, oxidant, radical additives, and/or destructive organic solvents. The catalyst shows a wide substrate scope and eminent functional group tolerance. The upscaled multigram synthesis using an inexpensive catalyst and easily available oxidant evidences the practical utility of the developed protocol. A plausible mechanism has been proposed with the help of a few controlled experiments, and kinetic and computational studies., (© 2024 Wiley-VCH GmbH.)

This work demonstrated the feasibility of an industrial-scale aerated static pile composting system for treating one of the common biowastes-soybean curd residue. The mixing ratios of the feedstock were optimized to achieve a carbon-nitrogen ratio and a moisture level in the ranges of 25-35 and 60-70%, respectively. This open-air composting system required 6-7 months to obtain a mature compost. Solvita and seed germination tests further confirmed the maturity of the compost, with 25% compost extract concentration yielding the best germination index in the absence of phytotoxicity. The bacterial and fungal compositions of the compost piles were further examined with metagenomic analysis. Thermoactinomyces spp., Oceanobacillus spp., and Kroppenstedtia spp. were among the unique bacteria found, and Diutina rugosa , Thermomyces dupontii , and Candida taylorii were among the unique fungi found in the compost piles, suggesting the presence of good microorganisms for degrading the organic biowastes.

Dry fruits and nuts are nutritious foods with several health-promoting properties. However, they are prone to contamination with aflatoxins at all stages of production and storage. The present study aimed to determine the natural occurrence of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), and total aflatoxins (AFT) in dates, pistachios, and walnuts collected from four districts of South Punjab (Pakistan), and to assess the associated health risks as estimated by dietary exposure and the Margin of Exposure (MoE) determinations. The contents of AFB1 and AFT in these food products were monitored during storage under three different conditions (open-air, hermetically closed jars, and refrigeration at 4 °C) to determine the most efficient conditions in preventing aflatoxin accumulation. HPLC-fluorescence analysis of 60 samples of these products for aflatoxin contamination showed that 52 (86.7%) samples were contaminated at different levels, with a maximum of 24.2 ng/g. The overall (all samples) mean concentrations of AFB1, AFB2, AFG1, AFG2, and AFT were 3.39 ± 2.96, 1.39 ± 1.68, 1.63 ± 1.48. 1.12 ± 1.23, and 7.54 ± 6.68, respectively. The Estimated Daily Intake (EDI) and MoE of aflatoxins through the consumption of the products ranged from 0.06 ng/kg bw/day to 2.0 ng/kg bw/day and from 84.84 to 2857.13, respectively, indicating that consumers are at high health risk. Significant differences were recorded between aflatoxin levels in the samples stored under different storage conditions, with storage under refrigeration (4 °C) being the most effective in controlling aflatoxin accumulation, although storage in closed jars was also efficient and offers a more flexible alternative to retailers. The findings of the study urge official authorities of Pakistan to implement appropriate regulatory and control measures and surveillance program to alleviate the potential public health risks associated with the consumption of dry fruits and nuts in the scope of their increased consumption.

The SARS-CoV-2 pandemic has revived the debate about the routes of virus transmission and their likelihoods. It is of utmost importance to assess the risks of contamination of susceptible people by infectious individuals and to evaluate the level of SARS-CoV-2 and other respiratory viruses transmission in the community. Most countries have imposed non-pharmaceutical measures to contain SARS-CoV-2 transmission, including physical distancing and mask wearing. Here we evaluated the spreading of viruses in open air using harmless Escherichia coli bacteriophages as a surrogate. Phages were sprayed towards Petri dishes seeded with bacteria at different lengths and angles. Our results showed that the transmission rate decreased exponentially with distance. The highest recorded transmission rate was [Formula: see text] PFU/plate when phages were sprayed from a 1 m distance, suggesting that the probability of transmission of a single virus at a 1 m distance is 1:100,000., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study reports the grafting of poly(ε-caprolactone) (PCL) on guar gum (GG) by in-situ ring-opening polymerization using tetra(phenylethynyl)tin (Sn(C≡CPh) 4 ) as catalyst. The hydroxyl groups of guar gum act as initiators for ε-caprolactone ring-opening polymerization and the resulting poly(ε-caprolactone) binds covalently to the polysaccharide. The highest stability of Sn(C≡CPh) 4 allows the reaction in open-air, thereby reducing the cost of the synthesis and provides polymers with high molar mass. Fourier transform infrared (FTIR) and the long-term stability of the suspension PCL-g-GG in dichloromethane confirmed the effectiveness of grafting of PCL into GG. The size exclusion chromatography (SEC) results show that the molar masse of grafted PCL could be modulated by varying the amount of guar gum. From thermogravimetric analysis and differential scanning calorimetry results the thermal stability of PCL-g-GG is greatly improved with different content of guar gum, also the melting temperature and crystallinity increased by increasing the GG content. The scanning electron microscopy (SEM) analyses showed the good adhesion between GG and PCL with 5% of GG contents. It was also revealed by contact angle measurements that the grafting of PCL to GG leads to a decrease of hydrophobicity of PCL. The micro-indentation hardness properties of the prepared PCL-g-GG were significantly improved, as compared to neat PCL., (Copyright © 2019. Published by Elsevier Ltd.)