Strong Antimicrobial Activity of Highly Stable Nanocomposite Containing AgNPs Based on Water-Soluble Triazole-Sulfonate Copolymer

A new hydrophilic polymeric nanocomposite containing AgNPs was synthesized by chemical reduction of metal ions in an aqueous medium in the presence of the copolymer. A new water-soluble copolymer of 1-vinyl-1,2,4-triazole and vinylsulfonic acid sodium salt (poly(VT-co-Na-VSA)) was obtained by free-radical copolymerization and was used as a stabilizing precursor agent. The structural, dimensional, and morphological properties of the nanocomposite were studied by UV–Vis, FTIR, X-ray diffraction, atomic absorption, transmission and scanning electron microscopy, dynamic and electrophoretic light scattering, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. Hydrodynamic diameter of macroclubs for the copolymer was 171 nm, and for the nanocomposite it was 694 nm. Zeta potential for the copolymer was −63.8 mV, and for the nanocomposite it was −70.4 mV. The nanocomposite had strong antimicrobial activity towards Gram-negative and Gram-positive microorganisms: MIC and MBC values were in the range of 0.25–4.0 and 0.5–8.0 μg/mL, respectively.

Proteomics based markers of clinical pain severity in juvenile idiopathic arthritis

Introduction Juvenile idiopathic arthritis (JIA) is a cluster of autoimmune rheumatic diseases occurring in children 16 years of age or less. While it is well-known that pain may be experienced during inflammatory and non-inflammatory states, much remains ambiguous regarding the molecular mechanisms that may drive JIA pain. Thus, in this pilot study, we explored the variability of the serum proteomes in relation to pain severity in a cohort of JIA patients. Methods Serum samples from 15 JIA patients (male and female, 12.7 ± 2.8 years of age) were assessed using liquid chromatography/mass spectrometry (LC/MS). Correlation analyses were performed to determine the relationships among protein levels and self-reported clinical pain severity. Additionally, how the expression of pain-associated proteins related to markers of inflammation (Erythrocyte Sedimentation Rate (ESR)) or morphological properties of the central nervous system (subcortical volume and cortical thickness) implicated in JIA were also evaluated. Results 306 proteins were identified in the JIA cohort of which 14 were significantly (p < 0.05) associated with clinical pain severity. Functional properties of the identified pain-associated proteins included but were not limited to humoral immunity (IGLV3.9), inflammatory response (PRG4) and angiogenesis (ANG). Associations among pain-associated proteins and ESR (IGHV3.9, PRG4, CST3, VWF, ALB), as well as caudate nucleus volume (BTD, AGT, IGHV3.74) and insular cortex thickness (BTD, LGALS3BP) were also observed. Conclusions The current proteomic findings suggest both inflammatory- and non-inflammatory mediated mechanisms as potential factors associated with JIA pain. Validation of these preliminary observations using larger patient cohorts and a longitudinal study design may further point to novel serologic markers of pain in JIA.

Influence of tin doping on the liquefied petroleum gas and humidity sensing properties of NiO nanoparticles

This research deals with study of enhanced liquefied petroleum gas (LPG) and humidity sensing properties of Sn-doped NiO pellets synthesized by chemical precipitation route. XRD, FTIR, SEM, and UV–Vis studies were employed to understand the effect of Sn doping on the structural, morphological, and optical properties of the NiO nanoparticles. XRD results revealed that doping of tin in NiO had a significant impact on the crystallite size, peak intensity, strain, lattice parameter, etc. The calculated crystallite size of pure and 3 mol% doped NiO was 33.2 nm and 13.3 nm, respectively. SEM micrographs revealed that the structure of the samples was irregular spheres and non-homogeneous. The dependence of LPG sensing properties on the structural and surface morphological properties has also been studied. The maximum response of 30.46% to 2.0 vol% of LPG was observed at room temperature (300 K). The same sample also shows high humidity sensing response of 87.11% towards 90% RH. Graphic abstract

Effect of compatibilisers on the cure characteristics and mechanical properties of ternary rubber blend composites

Purpose This paper aims to study the effects of various compatibilisers (maleic anhydride (MAH), methyl methacrylate/butyl acrylate emulsion lattice, and adhesion system (HRH)) on properties of carbon black (CB) filled with natural rubber (NR)/styrene-butadiene rubber (SBR)/ nitrile butadiene rubber (NBR) blends). A series of NR/SBR/NBR blends at a 30/30/40 blend ratio reinforced with 45 phr of CB was prepared using the master-batch method. Design/methodology/approach The tensile properties such as the tensile strength, stress at 100, 200 and 300% elongations, and elongation at break (EB)% were studied. Additionally, the morphological properties of compatibilised and uncompatibilised composites were compared to determine the optimal compatibiliser content. Findings The influence of compatibilisers appeared on all the properties studied. The properties of the blends compatibilised with prepared emulsion are very distinct from those of blends compatibilised with MAH and adhesion systems. Research limitations/implications Interactions among the different components of blends at the interfaces have a high impact on the interfacial properties of the rubber blend. Practical implications Compatibilisers significantly improve the physicomechanical properties of the resulting composites with the loading of investigated compatibilisers because of the uniform dispersion of CB in the rubber matrix. Social implications Using blends in the rubber industry leads to high-efficiency production of low-cost products. Originality/value The rubber blending has a significant positive effect on a wide range of applications such as structural applications, aerospace, military, packaging, tires and biomedical. Hence, improving the compatibility of blends will make new materials suitable for new applications.

A Quantified Study of the Resistance of Duplex Stainless Steels to HISC: Part 1 - Significance of the three-dimensional phase distributions and morphological properties on hydrogen transport

This paper is associated with a larger programme of research, studying the resistance to hydrogen-induced stress cracking (HISC) of a wrought and a hot isostatically-pressed (HIP) UNS S31803 duplex stainless steel (DSS), with respect to both the independent and interactive effects of the three key components of HISC: microstructure, stress/strain, and hydrogen. In the first part presented here, several material properties such as the three-dimensional (3D) microstructure, distribution and morphology/geometry of the two phases, i.e. ferrite and austenite, and their significance on hydrogen transport have been determined quantitatively, using X-ray computed tomography (CT) microstructural data analysis and modelling. This provided a foundation for the study to compare resistance to HISC initiation and propagation of the two DSSs with differing microstructures, using hydrogen permeation measurements, environmental fracture toughness testing of single-edge notched bend test specimens, in the Part 2 paper of this study [1].

Morphological characterization and genetic analysis of tri-pistil trait, a precisely regulated pistil number mutation in bread wheat

Bread wheat (Triticum aestivum L.) is an important source of nutrients for humans. Therefore, improvement of its yields is essential to feed the increasing world population. The tri-pistil (TRP) trait in wheat has a high potential for increasing yields. We obtained a pure tri-pistil wheat line, 4045, and evaluated its morphological properties. The 4045 wheat line stably produced three independently inherited pistils, which led to 1-3 grains in each floret. Among the three pistils, two lately emerged pistils initiated at late anther primordia stage to early tetrads stage. Genetic analysis revealed that there were TRP penetrance variations among the 11 F1 populations of 4045. Fine mapping narrowed the single dominant TRP locus to a 97.3 kb region, containing two candidate genes, on the 2DL chromosome. However, further gene sequence, functional as well as comparative genomic analyses ruled out the only two candidate genes. Therefore, TRP is high-likely a unique gain-of-function mutation that does not exist in normal wheat genome. Transcriptome analysis of floral homeotic genes revealed that expressions of the C-class TaAG-2s, which are essential for carpel specification, significantly increased in 4045, implying that TaAG-2s have played important roles in TRP-regulated tri-pistil formation. This study highlights that TRP leads to a precisely regulated pistil number increase (PRPNI) mutations and proposed a regulatory model of PRPNI pistil architecture. PRPNI offers a novel abnormal pistil development resource for research of floral architectures and potential on crop yield improvement.

Structural and Functional Characterization of Four Novel Fibrinogen Mutations in FGB Causing Congenital Fibrinogen Disorder

Congenital fibrinogen disorders are caused by mutations in genes coding for fibrinogen and may lead to various clinical phenotypes. Here, we present a functional and structural analysis of 4 novel variants located in the FGB gene coding for fibrinogen Bβ chain-heterozygous missense BβY416C and BβA68S, homozygous nonsense BβY345*, and heterozygous nonsense BβW403* mutations. The cases were identified by coagulation screening tests and further investigated by various methods. Fibrin polymerization had abnormal development with decreased maximal absorbance in all patients. Plasmin-induced fibrin degradation revealed different lytic phases of BβY416C and BβW403* than those of the control. Fibrinopeptide cleavage measured by reverse phase high pressure liquid chromatography of BβA68S showed impaired release of fibrinopeptide B. Morphological properties, studied through scanning electron microscopy, differed significantly in the fiber thickness of BβY416C, BβA68S, and BβW403*, and in the fiber density of BβY416C and BβW403*. Finally, homology modeling of BβA68S showed that mutation caused negligible alternations in the protein structure. In conclusion, all mutations altered the correct fibrinogen function or structure that led to congenital fibrinogen disorders.

Preparation and Characterization of Multi-doped Porous Carbon Nanofibers from Carbonization in Different Atmospheres and Their Oxygen Electrocatalytic Properties Research

Recently, electrocatalysts for oxygen reduction reactions (ORRs) as well as oxygen evolution reactions (OERs) hinged on electrospun nanofiber composites have attracted wide research attention. Transition metal elements and heteroatomic doping are important methods used to enhance their catalytic performances. Lately, the construction of electrocatalysts based on metal-organic framework (MOF) electrospun nanofibers has become a research hotspot. In this work, bimetallic NixCoy-ZIF nanocrystals were synthesized in an aqueous solution, followed by NixCoy-ZIF/PAN electrospun nanofiber precursors, which were prepared by a simple electrospinning method. Bimetal (Ni-Co) porous carbon nanofiber catalysts doped with nitrogen, oxygen, and sulfur elements were obtained at high-temperature carbonization treatment in different atmospheres (Ar, Air, and H2S), respectively. The morphological properties, structures, and composition were characterized by SEM, TEM, SAED, XRD, and XPS. Also, the specific surface area of materials and their pore size distribution was characterized by BET. Linear sweep voltammetry curves investigated catalyst performances towards oxygen reduction and evolution reactions. Importantly, Ni1Co2-ZIFs/PAN-Ar yielded the best ORR activity, whereas Ni1Co1-ZIFs/PAN-Air exhibited the best OER performance. This work provides significant guidance for the preparation and characterization of multi-doped porous carbon nanofibers carbonized in different atmospheres.

Agglutination processes of activated sludge cultures induced by extracellular lectins

We examine the agglutinating ability of five compounds, namely, A1, A2, A3, A4 and BS1, isolated from activated sludge on selective media typical of a number of dominant microbial cultures that contribute to the formation of microbial aggregates. The morphological properties of the isolates and their lectin activity, as well as the physiological and biochemical properties of individual isolates were studied; microorganisms in their composition were identified. We assessed the capacity of the isolates under study to synthesize an exopolysaccharide matrix, as well as the sedimentation of activated sludge under the action of the native solution and culture liquid of the BS1 isolate. Based on their capacity to agglutinate, the BS1 and A2 isolates were selected for further research as producers of extracellular lectins and objects of agglutination, respectively. The biophysiochemical properties and molecular-genetic identification of the BS1 isolate allowed the degree of identity with r. Bacillus to be defined (96.19%); for the A2 isolate, 92.93% identity with p. Shigella and p. Escherichia was determined. To assess the capacity to synthesize a biofilm matrix, the BS1 and A2 isolates were cultivated on an agar nutrient solution using Congo Red dye. According to the obtained results, the isolates are capable of synthesizing an exopolysaccharide matrix, the main component of bacterial biofilms. The research results on the sedimentation of activated sludge induced by the native solution and culture liquid of BS1 showed the following. The sedimentation rate of activated sludge increased significantly at the beginning of the process upon adding a BS1 cell suspension, while the introduction of the native solution of BS1 intensified the process following 5 minutes of contact. The obtained experimental data suggest that the media containing extracellular bacterial lectins can be effectively used as a coagulant (flocculant) for the sedimentation of activated sludge.