An Investigation into the Nature of the Oxide Layer Formed on Kovar (Fe–29Ni–17Co) Wires Following Oxidation in Air at 700 and 800 °C

This work provides new insight and evidence that challenges and extends the accepted view of the oxidation behaviour of Kovar (ASTM-15). Specimens of 2 mm diameter Kovar wire were oxidised in air at 700 or 800 °C for 10 min. The resulting oxide layers were analysed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, scanning transmission electron microscopy and Raman spectroscopy. Oxide layers of approximately 2 and 4 µm thickness were formed at 700 and 800 °C, respectively. These were found to contain iron, cobalt and traces of nickel. The combination of analysis techniques revealed that the oxide contains Fe₂O₃ in addition to (Fe, Co, Ni)₃O₄, a spinel oxide, in contrast to the combinations of Fe₃O₄, Fe₂O₃ and FeO that are typically reported. The oxide layer was found to be complex, consisting of multiple layers with different compositions, which is overlooked in the existing literature.     

Extracellular Heat Shock Proteins as Therapeutic Targets and Biomarkers in Fibrosing Interstitial Lung Diseases

Interstitial lung diseases (ILDs) include a large number of diseases and causes with variable outcomes often associated with progressive fibrosis. Although each of the individual fibrosing ILDs are rare, collectively, they affect a considerable number of patients, representing a significant burden of disease. Idiopathic pulmonary fibrosis (IPF) is the typical chronic fibrosing ILD associated with progressive decline in lung. Other fibrosing ILDs are often associated with connective tissues diseases, including rheumatoid arthritis-ILD (RA-ILD) and systemic sclerosis-associated ILD (SSc-ILD), or environmental/drug exposure. Given the vast number of progressive fibrosing ILDs and the disparities in clinical patterns and disease features, the course of these diseases is heterogeneous and cannot accurately be predicted for an individual patient. As a consequence, the discovery of novel biomarkers for these types of diseases is a major clinical challenge. Heat shock proteins (HSPs) are molecular chaperons that have been extensively described to be involved in fibrogenesis. Their extracellular forms (eHSPs) have been recently and successfully used as therapeutic targets or circulating biomarkers in cancer. The current review will describe the role of eHSPs in fibrosing ILDs, highlighting the importance of these particular stress proteins to develop new therapeutic strategies and discover potential biomarkers in these diseases.     

Circulating Extracellular Vesicles: The Missing Link between Physical Exercise and Depression Management?

Depression is associated with an increased risk of aging-related diseases. It is also seemingly a common psychological reaction to pandemic outbreaks with forced quarantines and lockdowns. Thus, depression represents, now more than ever, a major global health burden with therapeutic management challenges. Clinical data highlights that physical exercise is gaining momentum as a non-pharmacological intervention in depressive disorders. Although it may contribute to the reduction of systemic inflammation associated with depression, the mechanisms underlying the beneficial physical exercise effects in emotional behavior remain to be elucidated. Current investigations indicate that a rapid release of extracellular vesicles into the circulation might be the signaling mediators of systemic adaptations to physical exercise. These biological entities are now well-established intercellular communicators, playing a major role in relevant physiological and pathophysiological functions, including brain cell–cell communication. We also reviewed emerging evidence correlating depression with modified circulating extracellular vesicle surfaces and cargo signatures (e.g., microRNAs and proteins), envisioned as potential biomarkers for diagnosis, efficient disease stratification and appropriate therapeutic management. Accordingly, the clinical data summarized in the present review prompted us to hypothesize that physical exercise-related circulating extracellular vesicles contribute to its antidepressant effects, particularly through the modulation of inflammation. This review sheds light on the triad “physical exercise–extracellular vesicles–depression” and suggests new avenues in this novel emerging field.     

Amino acid changes in the repressor of bacteriophage lambda due to temperature-sensitive mutations in its cI gene and the structure of a highly temperature-sensitive mutant repressor

The mutant cIts genes from seven different cIts phages carryingtsU50, tsU9, tsU46, ts1, tsU51, tsI-22 and ts2 mutations werecloned in plasmid. The positions of these mutations and theresulting changes of amino acids in the repressor were determinedby DNA sequencing. The first four mutations mapping in the N-terminaldomain show the following changes: I21S, G53S, A62T and V73A,respectively. Of the three remaining mutations mapping in theC-terminal domain, cItsI-22 and cIts2 show N207T and K224E substitutionsrespectively, while the mutant cItsU51 gene carries F141I andP153L substitutions. Among these ts repressors, CIts2 havingthe charge-reversal change K224E was overexpressed from tacpromoter in a plasmid and purified, and its structure and functionwere studied. Operator-binding studies suggest that the ts2repressor is somewhat defective in monomer–dimer equilibriumand/or cooperativity even at permissive temperatures and losesits operator-binding ability very rapidly above 25°C. Comparativestudies of fluorescence and CD spectra, sulfhydryl group reactivityand elution behaviour in size-exclusion HPLC of both wild-typeand ts2-mutant repressors at permissive and non-permissive temperaturessuggest that the C-terminal domain of the ts2 repressor carryinga K224E substitution has a structure that does not favor tetramerformation at non-permissive temperatures.     

Ion transport studies in PEO:NH4ClO4 polymer electrolyte and its composite with Al2O3

Composition, temperature and humidity dependence of ionic conductivity in polyethylene oxide (PEO):NH₄ClO₄ polymer electrolyte composite obtained by the dispersal of Al₂O₃ is reported. The dispersal of Al₂O₃ introduces significant changes in the conductivity vs. composition isotherm. The conductivity of the composite peaks at two concentrations of Al₂O₃ is ~2 × 10^?5 S cm^?1. For studying ion dynamics, motional narrowing of ¹H NMR line with temperature is also reported. In PEO:NH₄ClO₄ (without dispersed Al₂O₃), two ¹H frequency-shifted NMR lines are seen (one of these have been assigned to the ¹H belonging to –CH₂–CH₂– chain of the polymer and the other to NH₄ ⁺ complexed with the chain). For the (PEO:NH₄ClO₄) + Al₂O₃ composites, however, one additional narrow peak is also seen at temperatures higher than 40 °C. This has been interpreted in terms of some hopping H⁺ ions getting loosely bonded to Al₂O₃, forming Al(OH)₃, which possibly releases an additional mobile protonic species (OH^?).     

Temperature Evolution During Processing of Thick‐Walled Anionic Polyamide 6 Composites: Experiment and Simulation

A 1‐D through‐the‐thickness transient heat transfer model is built to simulate the curing process of thick‐walled glass‐fibre‐reinforced anionic polyamide‐6 (APA‐6) composites. The temperature and the degree of polymerisation through the thickness of the composite are calculated and compared to the experimentally obtained results. The kinetic models describing the polymerisation behaviour of APA‐6 are implemented in the model. The kinetic model not taking into account the convection in the polymerisation process shows the best results. It is found that the predicted temperature profiles agree well with the experimental data.

     

Dry colour prediction of leather from its wet state

The present investigation describes the development of a regression model for dry colour prediction based on the colour of wet leather. Such a prediction will be useful in the colour matching of leather – the time delay in drying of wet leather and determination of the final colour can be avoided. The use of computer technology interfaced with a reflectance spectrophotometer provides a novel approach to the prediction of dry colour from wet colour. In this study, five different regression models, i.e. linear fit, log fit, quadratic fit, log quadratic fit and cubic fit, were developed, with the dry reflectance of the leather sample as a dependent variable and the wet reflectance of the leather as an independent variable. The relationship between moisture content and surface leather colour, a prerequisite for enabling prediction, was studied. The obtained log quadratic model can be used for accurate prediction of dry colour from wet colour.     

The Effects of Treatment with the White-Rot Fungus Trametes Versicolor and Laccase Enzymes on the Brightness of Douglas-Fir Heartwood Derived Thermomechanical Pulps

Abstract

Douglas-fir is a significant west coast tree species that cannot be used as a furnish in the high yield thermomechanical pulping process (TMP) because of the low brightness caused by the high chromophoric extractive content in its heartwood. Trametes versicolor and laccase enzymes were assessed for their potential to improve the brightness of Douglas-fir heartwood derived TMP. Treatments with Tversicolor were relatively unsuccessful. Although the application of laccase without a mediator decreased the unbleached brightness of heartwood pulps from 40.1 to 34.1 % ISO, after bleaching with H₂O₂, it was found that the laccase treatment increased the bleached brightness from 58 to 61 % ISO. Biological treatments were performed alone and in combination with methanol and alkaline extraction. When pulps were extracted with methanol prior to treatment with laccase and the mediator HBT, the hydrogen peroxide bleached brightness increased from 63 to 64.5 % ISO compared to the non-laccase treated, methanol extracted controls.     

Biohydrometallurgy of secondary metal resources: a potential alternative approach for metal recovery

Research on biohydrometallurgy of secondary metal resources is primarily focused on the leaching of valuable metals. For secondary metal resources biological processing can be an economically more effective and environmentally friendlier alternative to traditional hydrometallurgical and pyrometallurgical processes. Therefore, biohydrometallurgy is a rapidly evolving biotechnology that has already provided revolutionary solutions to old problems associated with recovery of metals by conventional pyrometallurgy and chemical metallurgy. This review evaluates various processes of recovery of metals from waste materials and commercial applications are discussed. Case studies and future technology directions are reviewed. © 2013 Society of Chemical Industry