GABA: A Key Player in Drought Stress Resistance in Plants

γ-aminobutyric acid (GABA) is a non-protein amino acid involved in various physiological processes; it aids in the protection of plants against abiotic stresses, such as drought, heavy metals, and salinity. GABA tends to have a protective effect against drought stress in plants by increasing osmolytes and leaf turgor and reducing oxidative damage via antioxidant regulation. Guard cell GABA production is essential, as it may provide the benefits of reducing stomatal opening and transpiration and controlling the release of tonoplast-localized anion transporter, thus resulting in increased water-use efficiency and drought tolerance. We summarized a number of scientific reports on the role and mechanism of GABA-induced drought tolerance in plants. We also discussed existing insights regarding GABA’s metabolic and signaling functions used to increase plant tolerance to drought stress.     

Phosphorylated nanocellulose fibrils/PVA nanocomposite membranes for biogas upgrading at higher pressure

ABSTRACT

High moisture uptake and excellent mechanical properties of cellulose nano-fibril (CNF) make it an interesting material to use as an additive in facilitated transport membranes. The objective of this work is to develop novel phosphorylated nanocellulose fibrils (PCNF)/polyvinyl alcohol (PVA) nanocomposite membranes for biogas upgrading. Results showed that the thickness of membrane increases with increasing concentration of PCNF. The addition of PCNF to pristine PVA membranes has beneficial effect for CO₂/CH₄ separation. However, maximum performance was achieved with 1 wt.% PCNF in 2% PVA at pH 12. Furthermore, increasing feed pressure caused a decrease in both permeability and selectivity.     

Model for the oxide thickness dependence of SILC generation based on anode hole injection process

A new model for the oxide thickness dependence of the SILC generation has been proposed on the basis of defects created by anode hole injection. This model which has been validated on oxides with thickness down to ≈3nm, allows the explanation of the bell-shaped behavior of the SILC variation with oxide thickness and predicts a strong reduction of the SILC intensity for ultra thin oxides operated in the direct tunneling regime.     

PVA/starch/propolis/anthocyanins rosemary extract composite films as active and intelligent food packaging materials

Active and intelligent food packaging films has taken more importance over conventional packaging. The aim of this study was to develop active and intelligent food packaging films based on bio-degradable polymers like polyvinyl alcohol and starch, incorporated with natural additives, that is, propolis extract (PE) and Anthocyanin. Boric acid was used as a cross-linker. The results proved the compatibility of films mixture. The mechanical strength was also measured and highest value was achieved 6.1 MPa for films containing 20% PE. Moreover, the maximum zone of inhabitation, that is, 21 and 15 mm, was also achieved at same composition against Escherichia coli and methicillin-resistant Staphylococcus aureus, respectively. Furthermore, all films had shown great color response against different pH ranging from 2 to 14. Finally, food spoilage test was performed using pasteurized milk. Films responded visibly by changing color and protected milk from spoilage. Hence, formulated bio-degradable active and intelligent films can be used as food packaging material.     

The Complex Mechanism of the Salmonella typhi Biofilm Formation That Facilitates Pathogenicity: A Review

Salmonella enterica serovar Typhi (S. typhi) is an intracellular pathogen belonging to the Enterobacteriaceae family, where biofilm (aggregation and colonization of cells) formation is one of their advantageous traits. Salmonella typhi is the causative agent of typhoid fever in the human body and is exceptionally host specific. It is transmitted through the fecal–oral route by consuming contaminated food or water. This subspecies is quite intelligent to evade the innate detection and immune response of the host body, leading to systemic dissemination. Consequently, during the period of illness, the gallbladder becomes a harbor and may develop antibiotic resistance. Afterwards, they start contributing to the continuous damage of epithelium cells and make the host asymptomatic and potential carriers of this pathogen for an extended period. Statistically, almost 5% of infected people with Salmonella typhi become chronic carriers and are ready to contribute to future transmission by biofilm formation. Biofilm development is already recognized to link with pathogenicity and plays a crucial role in persistency within the human body. This review seeks to discuss some of the crucial factors related to biofilm development and its mechanism of interaction causing pathogenicity. Understanding the connections between these things will open up a new avenue for finding therapeutic approaches to combat pathogenicity.     

NiFe2O4/SiO2 nanostructures as a potential electrode material for high rated supercapacitors

Engineered materials are crucial for the higher efficiency of supercapacitors. Current work presents roughly shaped spherical NiFe₂O₄ nanoparticles dispersed in the SiO₂ matrix NiFe₂O₄/SiO₂ as a newfangled electrode material for supercapacitors with remarkable performance. Designing the NiFe₂O₄/SiO₂ nanostructure with a sol-gel method followed by the Stober method to grow silica has instigated NiFe₂O₄/SiO₂ as dynamic material with higher electrochemical activity. Physicochemical aspects of NiFe₂O₄/SiO₂ nanostructures are evaluated using Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analysis. The electrochemical activity is evaluated by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) representing the comparable efficiency and reversibility of the electrode materials. The prepared electrode shows a capacitance of 925 F/g (154.1 mAh/g or 555 C/g) at 1 A/g, with 95.5% capacitance retention after 5000 cycles at 20 mA/cm². The improved electrochemical performance of the NiFe₂O₄/SiO₂ electrode can be subjected to prompt diffusion process provided by NiFe₂O₄/SiO₂ and enhanced redox reactions owing to the high surface area. The mentioned features decrease the total impedance of the electrodes as suggested by electrochemical impedance spectroscopy (EIS).     

A comparative experimental investigation of deep-hole micro-EDM drilling capability for cemented carbide (WC-Co) against austenitic stainless steel (SUS 304)

Microelectro-discharge machining (micro-EDM) has become a widely accepted non-traditional material removal process for machining difficult-to-cut but conductive materials effectively and economically. The present study aims to investigate the feasibility of machining deep microholes in two difficult-to-cut materials: cemented carbide (WC-Co) and austenitic stainless steel (SUS 304) using the micro-EDM drilling. The effect of discharge energy and electro-thermal material properties on the performance of the two work materials during the micro-EDM drilling has also been investigated. The micro-EDM drilling performance of two materials has been assessed based on the quality and accuracy of the produced microholes, machining stability, material removal rate (MRR), and electrode wear ratio. The results show that deep-hole micro-EDM drilling is technically more feasible in WC-Co as it offers microholes with smooth and burr-free surfaces at the rim in addition to improved circularity and lower overcut than those provided by SUS 304. Moreover, WC-Co exhibits better machinability during the deep-hole micro-EDM drilling, providing relatively higher MRR and stable machining.     

A framework for weighting of criteria in ranking stage of material selection process

Material selection is an onerous process of design activities which needs to be carefully carried out in order to increase the probability of success. A lot of multi-criteria decision-making methods have been proposed in material selection, many of which require quantitative weights for the attributes. Since weights play a very significant role in the ranking results of the materials, this paper presents a framework for determining importance degree of criteria to overcome the shortcomings of this subject in material selection. Furthermore, the suggested framework covers the situation of interdependent relationship between the criteria which has not been surveyed in material selection yet. An example was considered to illustrate how this framework is conducted. On the basis of the numerical results, it can be concluded that the proposed method can soundly deal with the material selection problems.