Experimental Evaluation of Food-Grade Semi-Refined Carrageenan Toxicity

The safety of food additives E407 and E407a has raised concerns in the scientific community. Thus, this study aims to assess the local and systemic toxic effects of the common food additive E407a in rats orally exposed to it for two weeks. Complex evaluations of the effects of semi-refined carrageenan (E407a) on rats upon oral exposure were performed. Local effects of E407a on the intestine were analyzed using routine histological stains and CD68 immunostaining. Furthermore, circulating levels of inflammatory markers were assessed. A fluorescent probe O1O (2- (2′-OH-phenyl)-5-phenyl-1,3-oxazole) was used for evaluating the state of leukocyte cell membranes. Cell death modes of leukocytes were analyzed by flow cytometry using Annexin V and 7-aminoactinomycin D staining. Oral administration of the common food additive E407a was found to be associated with altered small and large intestinal morphology, infiltration of the lamina propria in the small intestine with macrophages (CD68⁺ cells), high systemic levels of inflammation markers, and changes in the lipid order of the phospholipid bilayer in the cell membranes of leukocytes, alongside the activation of their apoptosis. Our findings suggest that oral exposure to E407a through rats results in the development of intestinal inflammation.     

New hard ternary Hf–Ir–B borides formed by reaction hafnium diboride with iridium

A variety of the ternary Hf–Ir–B phases formed via the reaction between iridium and hafnium diboride at elevated temperatures was found. The data on the phase and elemental composition, as well as crystal structure, obtained by powder and single-crystal X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectrometer, and time-of-flight neutron diffraction analysis unambiguously confirm that HfIr₃B_x solid solution, two known ternary borides (HfIr₃B₄, Hf₂Ir₅B₂), as well as two novel ternary HfIr_2.1B_1.3 and HfIr_5.7B_2.7 phases, are formed at elevated temperatures. This result is fundamentally different from that previously obtained by us for the Hf–Ir–C system in which only one binary intermetallic compound, HfIr₃, was produced. The measured Vickers microhardness for all the aforementioned ternary borides (13–19 GPa) allows us to consider them hard. The coefficients of thermal expansion of ternary borides were measured by in situ high-temperature X-ray analysis.     

Study on polybenzoxazinone membrane in pervaporation processes

Poly(benz‐3,1‐oxazinone‐4) was prepared by thermal cyclization of its hydrolytically stable precursor polyamic acid. Both polymer and its precursor were investigated as membrane materials. Thermogravimetric analysis and contact angle measurements were carried out for characterization of peculiarity of membrane compositions and analysis of membrane surface. Pervaporation of water–isopropanol mixture was studied in the wide range of feed composition. To interpret the pervaporation transport properties of the membranes, swelling experiments were performed, kinetic curves of sorption and desorption were plotted, and basic sorption and diffusion parameters were analyzed. It was established that poly(benz‐3,1‐oxazinone‐4) membrane is extremely effective in dehydration of water–isopropanol mixture and shows high separation factor. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4024–4031, 2013     

Oxygen-free precursor for chemical vapor deposition of gold films: thermal properties and decomposition mechanism

Thermal properties of oxygen-, phosphorus-, and halogen-free dimethylgold(III) diethyldithiocarbamate complex (CH₃)₂AuS₂CN(C₂H₅)₂ (gold, dimethyl(diethylcarbamodithioato -S,S′)-) having excellent storage stability and the mechanism of its decomposition to elemental gold were studied. Saturated vapor pressure was found to be ~10⁻³–10⁻¹ Torr at 50–90°C. Decomposition of the vapor on the surface starts at T = 210°C. The temperature dependence of gas phase composition was studied using the original mass spectrometric technique, it was established that the decomposition of the compound on the surface in vacuum follows three main pathways. Two of them result in the formation of elemental gold, saturated C2–C4 alkanes and (1) protonated ligand or (2) methylated ligand. The third one results in elemental gold and gaseous products: C2–C3 alkylmercaptanes and CH₃SCN(C₂H₅)₂. The formation of gold as a sole solid product within the temperature range 210–240°C was confirmed by X-ray photoelectron spectroscopy analysis. It was shown that the compound exhibits the best combination of volatility, thermal, and storage stability among volatile organogold complexes and thus it may be a promising precursor for obtaining gold films by chemical vapor deposition.     

Finite Element Simulations of Crack Propagation in Al_2O_3/6061Al Composites

In this work, the local fracture initiation behaviour of an Al2O3/6061 Al composite is studied numerically. The damage behaviour of the microstructure is evaluated in consideration of the path and the amount of damage as well as the stress–strain performance of the microstructure. The damage behaviour of the ductile matrix has been simulated using the damage parameter D. For the simulation of fracture of the ceramic particles, a normal stress criterion is applied. For the analysis of the damage behaviour of the transition zone between particulate and matrix, both damage models(D parameter and normal stress criteria) are applied in this region. Parameter studies of crack propagation prediction in the Al2O3/6061 Al composite on the basis of an Element Elimination technique have been performed for two differently heat-treated variants resulting in different mechanical properties. In addition, residual stress effects on the damage behaviour are examined for various microstructural situations.     

Sensitive Immunofluorescent Detection of the PRAME Antigen Using a Practical Antibody Conjugation Approach

Bioconjugation of antibodies with various payloads has diverse applications across various fields, including drug delivery and targeted imaging techniques. Fluorescent immunoconjugates provide a promising tool for cancer diagnostics due to their high brightness, specificity, stability and target affinity. Fluorescent antibodies are widely used in flow cytometry for fast and sensitive identification and collection of cells expressing the target surface antigen. Nonetheless, current approaches to fluorescent labeling of antibodies most often use random modification, along with a few rather sophisticated site-specific techniques. The aim of our work was to develop a procedure for fluorescent labeling of immunoglobulin G via periodate oxidation of antibody glycans, followed by oxime ligation with fluorescent oxyamines. Here, we report a novel technique based on an in situ oxime ligation of ethoxyethylidene-protected aminooxy compounds with oxidized antibody glycans. The approach is suitable for easy modification of any immunoglobulin G, while ensuring that antigen-binding domains remain intact, thus revealing various possibilities for fluorescent probe design. The technique was used to label an antibody to PRAME, a cancer-testis protein overexpressed in a number of cancers. A 6H8 monoclonal antibody to the PRAME protein was directly modified with protected-oxyamine derivatives of fluorescein-type dyes (FAM, Alexa488, BDP-FL); the stoichiometry of the resulting conjugates was characterized spectroscopically. The immunofluorescent conjugates obtained were applied to the analysis of bone marrow samples from patients with oncohematological diseases and demonstrated high efficiency in flow cytometry quantification. The approach can be applied for the development of various immunofluorescent probes for detection of diagnostic and prognostic markers, which can be useful in anticancer therapy.     

Functional Analysis of the PCCA and PCCB Gene Variants Predicted to Affect Splicing

It is estimated that up to one-third of all variants causing inherited diseases affect splicing; however, their deleterious effects and roles in disease pathogenesis are often not fully characterized. Given their prevalence and the development of various antisense-based splice-modulating approaches, pathogenic splicing variants have become an important object of genomic medicine. To improve the accuracy of variant interpretation in public mutation repositories, we applied the minigene splicing assay to study the effects of 24 variants that were predicted to affect normal splicing in the genes associated with propionic acidemia (PA)—PCCA and PCCB. As a result, 13 variants (including one missense and two synonymous variants) demonstrated a significant alteration of splicing with the predicted deleterious effect at the protein level and were characterized as spliceogenic loss-of-function variants. The analysis of the available data for the studied variants and application of the American College of Medical Genetics and the Association for Molecular Pathology (ACMG/AMP) guidelines allowed us to precisely classify five of the variants and change the pathogenic status of nine. Using the example of the PA genes, we demonstrated the utility of the minigene splicing assay in the fast and effective assessment of the spliceogenic effect for identified variants and highlight the necessity of their standardized classification.     

Increasing the performance of asymmetric pervaporation membranes for the separation of methanol/methyl-tert-butyl ether mixtures by the introduction of sulfonated polyimide into the poly(amide-imide) matrix

A series of novel asymmetric membranes from polymer composites of poly(amide-imide) with various content of sulfonated polyimide (1–6 wt%) was obtained through the nonsolvent-induced phase separation process. Selective transport properties of the obtained materials were investigated in terms of pervaporation separation of methanol/methyl-tert-butyl ether mixtures at different temperatures. The introduction of the sulfonated polyimide to the poly(amide-imide) matrix leads to a significant increase in membrane flux and an overall decrease in the process selectivity. Composite membranes having 1 wt% sulfonated polyimide in the matrix showed increased values of membrane flux (0.960 kg m⁻² h⁻¹ in comparison with 0.682 kg m⁻² h⁻¹ for unmodified membranes at 40°C, 10 wt% methanol), while having similar selectivity values (79.2 wt% methanol in permeate in comparison with 82 wt% for unmodified membranes at 40°C, 10 wt% methanol). Modified membrane showed the highest separation factor of 147 while separating methanol from its 3 wt% mixture with methyl-tert butyl ether at 52°C with the overall flux of 1.01 kg m⁻² h⁻¹. A semiempirical mathematical model was developed and applied to test the efficiency of obtained membranes in the hybrid process of methanol/methyl-tert-butyl ether mixtures separation.     

Slurry Phase Hydrogenation of CO2 to Methanol Using Supported In2O3 Catalysts as Promising Approach for Chemical Energy Storage

A promising approach for chemical energy storage from fluctuating renewable electricity is methanol synthesis from CO₂ and hydrogen in a slurry reactor concept, due to efficient heat storage and easy reactor control. In combination with a promising In₂O₃/ZrO₂ catalyst and mineral oil as carrier liquid, efficient methanol production under a wide range of changing process conditions is shown for the first time. A maximum methanol productivity of 2.1 g_MeOHg_In⁻¹h⁻¹ and multiple recycling stability of the catalyst and the carrier liquid was achieved, showing no significant decrease in methanol yields.     

Phase Relations in the ZrO<Subscript>2</Subscript>-Nd<Subscript>2</Subscript>O<Subscript>3</Subscript>-Y<Subscript>2</Subscript>O<Subscript>3</Subscript> System: Experimental Study and Advanced Thermodynamic Modeling

Phase equilibria in the ZrO₂-Nd₂O₃-Y₂O₃ system at 1523-1873 K have been investigated by x-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive x-ray spectroscopy (SEM/EDX). Temperatures of phase transformations were determined by differential thermal analysis. Temperatures of invariant reactions in the ZrO₂-Nd₂O₃ system F = A + Pyr and H = F + A were determined as 1763 and 2118 K respectively and thermodynamic parameters of phases were re-assessed. Phase transformations in ternary systems were determined at 1732 K for composition ZrO₂-48.46Nd₂O₃-5.38Y₂O₃ (mol%) and at 1744 and 1881 K for composition ZrO₂-79.09Nd₂O₃-2.75Y₂O₃ (mol%). They were interpreted using XRD investigation before and after DTA as Pyr + B → F, Pyr → F and A → B, respectively. The solubility of the Y₂O₃ in pyrochlore phase was found to exceed 10 mol%. The thermodynamic parameters of the ZrO₂-Nd₂O₃-Y₂O₃ system were reassessed taking into account solubility of Y₂O₃ in the Nd₂Zr₂O₇ pyrochlore phase (Pyr). It is assumed that Y³⁺ substitutes Nd³⁺ and Zr⁴⁺ in their preferentially occupied sublattices. Ternary parameter was introduced into fluorite phase (F) for better reproducing of phase equilibria. Mixing parameters were reassessed for phase A (Nd₂O₃ based solution), monoclinic phase B and cubic phase C (Y₂O₃ based solution). The isothermal sections calculated for the ZrO₂-Nd₂O₃-Y₂O₃ system are in the reasonable agreement with experimental results.