Single Amino Acid Exchange in ACTIN2 Confers Increased Tolerance to Oxidative Stress in Arabidopsis der1–3 Mutant

Single-point mutation in the ACTIN2 gene of the der1–3 mutant revealed that ACTIN2 is an essential actin isovariant required for root hair tip growth, and leads to shorter, thinner and more randomly oriented actin filaments in comparison to the wild-type C24 genotype. The actin cytoskeleton has been linked to plant defense against oxidative stress, but it is not clear how altered structural organization and dynamics of actin filaments may help plants to cope with oxidative stress. In this study, we characterized root growth, plant biomass, actin organization and antioxidant activity of the der1–3 mutant under oxidative stress induced by paraquat and H₂O₂. Under these conditions, plant growth was better in the der1–3 mutant, while the actin cytoskeleton in the der1–3 carrying pro35S::GFP:FABD2 construct showed a lower bundling rate and higher dynamicity. Biochemical analyses documented a lower degree of lipid peroxidation, and an elevated capacity to decompose superoxide and hydrogen peroxide. These results support the view that the der1–3 mutant is more resistant to oxidative stress. We propose that alterations in the actin cytoskeleton, increased sensitivity of ACTIN to reducing agent dithiothreitol (DTT), along with the increased capacity to decompose reactive oxygen species encourage the enhanced tolerance of this mutant against oxidative stress.     

Synthetic resins: II: Preparation and characterization of resins prepared from aminoacetophenone

A number of resins were prepared by condensing m-aminoacetophenone with substituted aromatic compounds and formaldehyde in the presence of acids and bases as catalyst. The resins were characterized by infrared spectra. The solubility parameters were calculated from Small's group contribution which agreed well with the experimental value. The bacteriocidal properties of the resins have been studied.     

Radiation induced graft copolymerization V. Graft copolymerization of methyl acrylate onto nylon-6 fiber

The radiation induced graft copolymerization of methylacrylate onto nylon-6 fiber at room temperature and in nitrogen medium was investigated. The effects of monomer, dose rate, inhibitor etc. on the graft yield have been investigated. The effect of solvents on the rate of grafting was studied from which the chain-transfer constant (C_s) of the solvent has been evaluated. Addition of certain inorganic salts was found to act as scavengers. The value of G_b, the number of branches per 100 eV of energy absorbed in the substrate polymer, was calculated. The density, moisture regain, alkali solubility, dyeability and thermal properties of the grafted nylon-6 fiber have been evaluated.     

Synthetic resins. V. Preparation and properties of substituted benzoic acid,hydroxyacetophenone and aniline/formaldehyde resins

A number of resin copolymers have been prepared by condensation of substituted aromatic compounds with formaldehyde in the presence of different acid catalysts. The resin copolymers were characterized by IR, thermal, X-ray diffraction, and by their reactivity ratios. The resins were found to possess high thermal stability. Activation energies of resin degradation were computed using the Freeman–Anderson method. The antifungal activities of several previously synthesized resins were studied.     

Potential biomarkers for early detection of acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is the main complication of allogeneic hematopoietic stem cell transplantation (HCT), resulting in considerable morbidity and mortality. Currently, the diagnosis of aGVHD is largely made based on clinical parameters and invasive biopsies. For the past 20 years, researchers have been trying to find reliable biomarkers to enable early and accurate diagnosis of aGVHD. Although a number of potential aGVHD biomarkers have been published, as yet, no validated diagnostic test is available. Proteomics encompasses a broad range of rapidly developing technologies, which have shown tremendous promise for early detection of aGVHD. In this article, we review the current state of aGVHD biomarker discovery, provide a summary of the key proteins of interest and the most common analytical procedures for the clinic, as well as outlining the significant challenges faced in their use.     

Synthetic resins. XX. Chelation ion exchange properties of resins derived from semicarbazone of 2-hydroxy acetophenone-substituted benzoic acid–formaldehyde

A number of resins have been synthesized by reacting orthohydroxy acetophenone-semicarbazone with substituted benzoic acid and formaldehyde in the presence of some acid and basic catalyst. The physicochemical properties of the resins have been reported. The ion exchange properties of the resins have been investigated. Influence of electrolytes on the metal uptake of Cu²⁺, Ni²⁺, Zn²⁺, Mg²⁺, and Mn²⁺ has been studied. The distribution of metal ions at different pH has also been reported. © 1992 John Wiley & Sons, Inc.     

NMR study of temperature-induced phase separation and polymer-solvent interactions in poly(vinyl methyl ether)/D2O/ethanol solutions

The changes in the dynamic structure during temperature-induced phase transition in D₂O/ethanol solutions of poly(vinyl methyl ether) (PVME) were studied using NMR methods. The effect of polymer concentration and ethanol (EtOH) content in D₂O/EtOH mixtures on the appearance and extent of the phase separation was determined. Measurements of ¹H and ¹³C spin-spin and spin-lattice relaxations showed the presence of two kinds of EtOH molecules: besides the free EtOH expelled from the PVME mesoglobules there are also EtOH molecules bound in PVME mesoglobules. The existence of two different types of EtOH molecules at temperatures above the phase transition was in solutions with polymer concentration 20 wt% manifested by two well-resolved NMR signals (corresponding to free and bound EtOH) in ¹³C and ¹H NMR spectra. With time the originally bound EtOH is slowly released from globular-like structures. From the point of view of polymer-solvent interactions in the phase-separated PVME solutions both EtOH and water (HDO) molecules show a similar behaviour so indicating that the decisive factor in this behaviour is a polar character of these molecules and hydrogen bonding.     

Thermal analysis of high‐performance mortar containing burnt clay shale as a partial portland cement replacement in the temperature range up to 1000 °C

Clay shale is a specific type of material that contains a large amount of kaolinite. Burnt clay shale belongs to a large group of pozzolans, and its pozzolanic properties are activated after burning at temperatures similar to those when kaolinite is transformed into metakaolin. In this study, fine powder of burnt clay shale was used for the design of a high‐performance mortar as a partial replacement for portland cement up to 60 wt.%. The prepared specimens were subjected to a thermal analysis by using differential scanning calorimetry, thermogravimetry, and thermodilatometry. The investigation was performed in the temperature range 25–1000 °C. The basic physical and mechanical properties were studied as well. It was demonstrated that it is possible to design and produce a high‐performance mortar containing fine burnt clay shale powder and that an appropriate amount of this replacement is up to 20 wt.%. Copyright © 2016 John Wiley & Sons, Ltd.