Long‐Life,High‐Rate Lithium–Sulfur Cells with a Carbon‐Free VN Host as an Efficient Polysulfide Adsorbent and Lithium Dendrite Inhibitor

Lithium–sulfur (Li‐S) batteries are a promising next‐generation energy‐storage system, but the polysulfide shuttle and dendritic Li growth seriously hinder their commercial viability. Most of the previous studies have focused on only one of these two issues at a time. To address both the issues simultaneously, presented here is a highly conductive, noncarbon, 3D vanadium nitride (VN) nanowire array as an efficient host for both sulfur cathodes and lithium‐metal anodes. With fast electron and ion transport and high porosity and surface area, VN traps the soluble polysulfides, promotes the redox kinetics of sulfur cathodes, facilitates uniform nucleation/growth of lithium metal, and inhibits lithium dendrite growth at an unprecedented high current density of 10 mA cm^?2 over 200 h of repeated plating/stripping. As a result, VN‐Li||VN‐S full cells constructed with VN as both an anode and cathode host with a negative to positive electrode capacity ratio of only ≈2 deliver remarkable electrochemical performance with a high Coulombic efficiency of ≈99.6% over 850 cycles at a high 4 C rate and a high areal capacity of 4.6 mA h cm^?2. The strategy presented here offers a viable approach to realize high‐energy‐density, safe Li‐metal‐based batteries.     

Identification and Discrimination of Methicillin Resistant Staphylococcus aureus Strains Isolated from Burn Wound Sites Using PCR and Authentication with MALDI-TOF–MS

The present study demonstrates isolation and identification of methicillin resistance Staphylococcus aureus (MRSA) strains in the samples collected from burn patients. About 106 swab samples were collected from burn patients of >40% burn injury and were subjected to isolation using nutrient agar followed by screening using Me Re Sa selective medium agar. A total of 10 isolates with identity to S. aureus were obtained and further authenticated using Polymerase Chain Reaction and matrix assisted laser desorption/ionization time of flight mass spectrometry analysis. Presence of mec A gene and the peak pattern observations suggested seven of the 10 isolates are MRSA. Thus, the present study emphasizes the process of identification of MRSA using two different bio-analytical techniques, which authenticate the presence of MRSA.     

Anaerobic Immobilized Yeast Cell Fermentation and Anaerobic Remediation in Hybrid Reactor for Mineralization of Dicarboxylic Acid Solid Waste

Summary The solid resinous product (SRP) containing unsaturated/saturated dicarboxylic acid residues, phthalic acid and maleic acid is discharged as a solid waste during cracking of benzene over vanadium at temperatures above 500°C in the dicarboxylic acid manufacturing industry. In the present study the solid waste was diluted with water to a concentration of 0.5% w/v for microbial degradation. The waste was fermented in a reactor containing mesoporous activated carbon on which was immobilized Saccharomyces cerevisiae at an optimum residence time of 24 h at pH 6.5. The immobilized-yeast-treated samples were further treated in an upflow anaerobic reactor at an hydraulic retention time (HRT) of 0.1038 days at a hydraulic flow rate of 7.34 × 10⁻³ m³/day and chemical oxygen demand (COD) loading rate of 2.19 kg/m³/day. The pathway followed in the degradation of dicarboxylic acid into end products by anaerobic metabolism in the yeast cell fermentor and in the upflow anaerobic reactor was confirmed through HPLC, Fourier transform infra red spectroscopy and proton and ¹³C NMR spectroscopy.     

Temperature and Photoperiod Influence Postharvest Needle Abscission of Selected Balsam Fir (Abies balsamea L. (Mill.)) Genotypes by Modulating ABA Levels

Seasonal changes in the concentration of abscisic acid (ABA) in current-year needles of two different genotypes (AB-NSD-004 and AB-NSD-184) were monitored in branches collected from 20-year-old balsam fir (Abies balsamea L. (Mill.)) trees over a period of 11 months. A significant genotype × harvesting time interaction was observed for endogenous ABA levels and postharvest needle retention duration (NRD). A consistent pattern of seasonal variation in ABA concentration was observed in both genotypes, with the highest amount of ABA (7,887 ng g^?1 DW) accumulating in April and May. The highest levels of ABA coincided with the lowest postharvest NRD regardless of genotype. Nevertheless, genotypes differed in their ABA concentrations. Branches of genotype AB-NSD-184 sampled during August exhibited 170 days of NRD whereas those collected in May and June registered the lowest NRD of around 40 days. There was a significant negative correlation (P < 0.05) between endogenous ABA concentrations and postharvest NRD in genotype AB-NSD-184. Also, an inverse relationship was observed between the average daily photoperiod and the postharvest NRD (R ² = 0.35; P = 0.000) in the same genotype. Together with average daily temperature, the R ² value for this correlation reached the highest (0.75; P ≤ 0.00). Genotypes differed in their physiological responses to environmental cues and thus differed in their postharvest qualities. Average daily photoperiod and maximum daily temperature are strongly linked to the postharvest NRD through modulating endogenous ABA concentration.     

Impediment to growth and yeast-to-hyphae transition in Candida albicans by copper oxide nanoparticles

Abstract

The effects of two prominent copper oxide nanoparticles (CuO-NP and Cu₂O-NP), with the oxidation state of Cu⁺⁺ (cupric) and Cu⁺ (cuprous), on Candida albicans were evaluated. CuO-NP and Cu₂O-NP were synthesized and characterized by XRD, FESEM, HR-TEM and Zeta potential. At sub-MIC (50?µg ml^?1), both cupric and cuprous oxide NPs prevented yeast-to-hyphae switching and wrinkling behaviour in C. albicans. The mechanism for the antifungal action of the two NPs differed; CuO-NP significantly elicited reactive oxygen species, whereas membrane damage was more pronounced with Cu₂O-NP. Real time PCR analysis revealed that CuO-NP suppressed the morphological switching of yeast-to-hyphae by down-regulating cph1, hst7 and ras1 and by up-regulation of the negative regulator tup1. In comparison, Cu₂O-NP resulted in down-regulation of ras1 and up-regulation of the negative regulators nrg1 and tup1. Between the two NPs, CuO exhibited increased antifungal activity due to its stable oxidation state (Cu⁺⁺) and its smaller dimensions compared with Cu₂O-NP.     

Significance of the variation in haemolymph copper-free- and -bound proteins during ageing and time of day in the crab Scylla serrata (Forskal)

During growth or ageing the total quantity of copper-free proteins in haemolymph of S. serrata increases at a higher rate than copper-bound proteins. The copper-free proteins are specifically degraded to meet the energy demand imposed by outburst of nocturnal activity during night hours, while the copper-bound proteins remain unaffected, signifying the importance of Cu-bound proteins in the normal physiology of the animal.