Development of New Cordierite‐Based Refractory Coatings for Casting Applications

In this study, new refractory coatings based on synthesized cordierite for the casting applications were developed. The investigation included starting raw materials characterization, synthesis of the cordierite, design of the refractory coating as final product, and its application testing. The obtained results pointed out that coating suspension sediment stability was crucial quality parameter. Design and optimization of the coatings composition, with controlled rheological properties included, were achieved by application of different coating components, namely different suspension agents and by alteration of the coating production procedure. Cordierite, used as filler, was obtained by means of synthesis in the solid‐state reaction on the basis of talc, kaolin, and alumina. The investigation showed that the application of these particular types of water/alcohol‐based coatings has positive influence on surface quality and structural and mechanical properties of the castings of aluminum alloys obtained by casting into sand molds by means of evaporable models method, that is, evaporate pattern casting process.     

Site‐Directed and Global Incorporation of Orthogonal and Isostructural Noncanonical Amino Acids into the Ribosomal Lasso Peptide Capistruin

Expansion of the structural diversity of peptide antibiotics was performed through two different methods. Supplementation‐based incorporation (SPI) and stop‐codon suppression (SCS) approaches were used for co‐translational incorporation of isostructural and orthogonal noncanonical amino acids (ncAAs) into the lasso peptide capistruin. Two ncAAs were employed for the SPI method and five for the SCS method; each of them probing the incorporation of ncAAs in strategic positions of the molecule. Evaluation of the assembly by HR‐ESI‐MS proved more successful for the SCS method. Bio‐orthogonal chemistry was used for post‐biosynthetic modification of capistruin congener Cap_Alk10 containing the ncAA Alk (Nε‐Alloc‐L ‐lysine) instead of Ala. A second‐generation Hoveyda–Grubbs catalyst was used for an in vitro metathesis reaction with Cap_Alk10 and an allyl alcohol, which offers options for post‐biosynthetic modifications. The use of synthetic biology allows for the in vivo production of new peptide‐based antibiotics from an expanded amino acid repertoire.     

Acute Intake of Plant Stanol Esters Induces Changes in Lipid and Lipoprotein Metabolism‐Related Gene Expression in the Liver and Intestines of Mice

The kinetics of plant stanol uptake and routing in 8‐week‐old C57BL/6J mice were determined after a plant stanol ester gavage. In addition, acute changes in intestinal and hepatic gene expression were investigated. Mice were fed a plant sterol/stanol poor diet from weaning. At the age of 8 weeks, they received an oral gavage consisting of 0.25 mg cholesterol + 50 mg plant stanol esters dissolved in olive oil. Animals were euthanized at different time points. In a second comparable set‐up, mesenteric lymph‐cannulated versus sham‐operated mice received the same oral gavage, which was now deuterium labeled. Intestinal and hepatic sitostanol concentrations increased within 15 min post‐gavage. This rapid hepatic appearance was absent in lymph‐cannulated mice, suggesting a very fast lymph‐mediated uptake. Hepatic mRNA expression of SREBP2 and its target genes rapidly decreased, whereas expression of LXR target genes increased. The intestinal SREBP2 pathway was increased, whereas the expression of LXR target genes hardly changed. The fivefold and sixfold increased expression of intestinal LDLr and PCSK9 is suggestive of TICE activation. We conclude that in C57BL/6J mice plant stanol kinetics are fast, and affect intestinal and hepatic gene expression within 15 min postprandial after lymph‐mediated uptake.     

What Governs Pickering Emulsion Properties During Preparation via Batch Rotor-Stator Homogenizers?

Pickering emulsions have received increasing interest in many fields of application recently. In designing Pickering emulsion properties, focus is typically laid on composition whereas the preparation process as another possible leverage is not considered in detail. Here, Pickering emulsions of constant composition were prepared using two dispersing heads of a rotor-stator homogenizer and compared in terms of Sauter mean diameters and rheology. It was found that the ratio of tip speed and gap width between rotor and stator is a better correlating parameter than tip speed only.