Residue 75 of Interleukin‐8 is Crucial for its Interactions with Glycosaminoglycans

The interactions between regulatory proteins such as interleukin‐8 (IL‐8) and glycosaminoglycans are of great interest both for the general understanding of regulatory processes in biology and for the development of implant coatings and innovative materials that suppress undesired immune responses and improve wound healing. In previous work, a number of residues of IL‐8 that interact strongly with several glycosaminoglycans (GAGs) have been identified. In particular, the negatively charged Glu75 was reported to be involved in interactions with charged GAGs. To improve understanding of the role of this residue, we generated a selectively ¹⁵N‐labeled E75K variant of IL‐8(1–77) by expressed protein ligation. NMR and fluorescence spectroscopy in combination with molecular modeling were applied to evaluate the particular role of residue 75 in interactions with GAGs. Remarkably, more residues in the variant responded to GAG binding than in the wild‐type. For the first time, we identified amino acids 34 to 36 as additional residues in the loop region of IL‐8(1–77) that participate in the interactions with GAGs. These findings indicate that the N terminus of the E75K variant is more important as a second binding site for GAGs than that of the wild‐type IL‐8(1–77).     

Enzyme‐Mediated Deposition of a TiO2 Coating onto Biofunctionalized WS2 Chalcogenide Nanotubes

A chemically specific and facile method for the biofunctionalization of WS₂ nanotubes (NT‐WS₂) is reported. The covalent modification strategy is based on the affinity of the nitrilotriacetic acid (NTA) side chain, which serves as a ligand for the surface binding to NT‐WS₂ and simultaneously as an anchor group for the binding of His‐tagged proteins to the polymer backbone. The polymer functionalized WS₂ nanotubes can be solubilized either in water or organic solvents; they are stable for at least one week. The probes were characterized by FT‐IR and UV‐vis spectroscopy. The immobilization of silicatein, a hydrolytic protein encountered in marine sponges, was visualized by scanning force microscopy (SFM) and confocal laser scanning microscopy (CLSM). The formation of the biotitania coating mediated by the immobilized silicatein onto the surface was characterized by scanning electron microscopy (SEM), and transmission electron microscopy (TEM).     

You are not alone: social capital and risk exposure in rural Ethiopia

This paper examines the impact of shocks on food security and the insurance role of social capital and informal social networks. In particular, by combining household panel data, weather data, self-reported shocks and detailed social capital information, the paper investigates the insurance role of social capital against covariate and idiosyncratic shocks. Our results suggest that both covariate and idiosyncratic shocks increase the prevalence of food insecurity. However, households with a higher stock of social capital were able to smooth consumption. We also found that food consumption is not insured through social capital when a shock affects the whole risk-sharing network. Moreover, we show that formal policy interventions such as access to consumption credit and safety nets are the only effective ways of insuring food consumption when a shock affects the entire risk-sharing network.     

Interface management: effective communication to improve process safety

Failure to successfully communicate maintenance activities, abnormal conditions, emergency response procedures, process hazards, and hundreds of other items of critical information can lead to disaster, regardless of the thoroughness of the process safety management system. Therefore, a well-functioning process safety program depends on maintaining successful communication interfaces between each involved employee or stakeholder and the many other employees or stakeholders that person must interact with. The authors discuss a process to identify the critical “Interfaces” between the many participants in a process safety management system, and then to establish a protocol for each critical interface.     

Successive Wyner–Ziv Coding Scheme and Its Application to the Quadratic Gaussian CEO Problem

In this paper, we introduce a distributed source coding scheme called successive Wyner-Ziv coding. We show that every point in the rate region of the quadratic Gaussian CEO problem can be achieved via successive Wyner-Ziv coding. The concept of successive refinement in single source coding is generalized to the distributed source coding scenario, which we refer to as distributed successive refinement. For the quadratic Gaussian CEO problem, we establish a necessary and sufficient condition for distributed successive refinement, where the successive Wyner-Ziv coding scheme plays an important role.     

Tissue distribution of perfluorinated surfactants in common guillemot (Uria aalge) from the Baltic Sea

Perfluorinated alkyl surfactants (PFAS) were investigated in tissues and organs of the common guillemot (Uria aalge) from the Baltic Sea. Concentrations of 11 perfluorinated carboxylates, four perfluorinated sulfonates, and perfluorooctane sulfonamide were determined in egg, liver, kidney, and muscle of adult guillemot, as well as in liver from chicks, all sampled in 1989. Additionally, whole herring homogenates from 2005 were analyzed, herring comprising a large part of guillemot's diet. Quantifiable concentrations of PFAS were found in all samples. Perfluorooctane sulfonate (PFOS) was predominant, followed by perfluorotridecanoate (PFTriDA) and perfluoroundecanoate (PFUnDA). The median concentration of PFOS was highest in eggs (325 ng/g wet weight (w wt)) followed by chick liver (309 ng/g w wt), kidney (127 ng/g w wt), adult liver (121 ng/g w wt), and muscle (14 ng/g w wt). Comparatively low levels of PFOS were found in herring, leaving a blurred picture of uptake routes. PFAS concentrations in livers of male and female guillemots did not differ significantly. Some PFAS showed higher concentrations in eggs than in female livers. The ratio of levels in egg/female liver, indicating mother-to-egg transfer capacity, increased with increasing PFAS chain length. PFOS showed a higher tendency for transfer than carboxylates of carbon chain lengths C9-C13.     

Einfluss der PVD‐Prozessparameter auf die Schichtnukleation und Struktur von CrN‐Schichten

Störstellen in Bauteiloberflächen wirken sich negativ auf die Schichtnukleation bei PVD‐Schichtsystemen aus. Sie können im anschließenden Schichtwachstum zu Defekten in der Schichtstruktur führen. Die Konsequenz ist eine Minderung der lokalen Haftfestigkeit, höhere Reibwerte und Fehlstellen in der Schicht. Diese begünstigen in korrosiven Medien die Entstehung von Korrosion. CrN‐Schichten sind für ihre hohe Härte und ihre guten Verschleißeigenschaften bekannt. Zudem weisen sie eine bessere Korrosionsbeständigkeit als Titan basierte Nitride auf. Die strukturellen und mechanischen Eigenschaften dieser Schichtsysteme können unter anderem durch die Veränderung der Biasspannung und des Stickstoffgehalts während des Schichtwachstums beeinflusst werden. Durch gezielte Variation dieser Beschichtungsparameter wurden CrN‐Schichten mit den bevorzugten Kristallgitterstrukturen (111) und (200) abgeschieden, mit dem Ziel deren Abdeckungsfähigkeit von Störstellen zu untersuchen. Für die gezielte Untersuchung und Vergleichbarkeit der Ergebnisse wurden Vickerseindrücke HV 0,5 als bewusst gestaltete Störstellen auf der Grundwerkstoffoberfläche aufgebracht. Als Grundwerkstoff diente niedriglegierter Stahl (100Cr6). Die Kristallgitterorientierungen der abgeschiedenen Schichten wurden zunächst anhand von röntgenographischen Messungen (XRD) identifiziert. Anhand weiterer rasterelektronenmikroskopischer Aufnahmen (REM) wurden die bewusst erzeugten Störstellen in Form von Vickerseindrücken und Ritzspuren sichtbar gemacht, mit dem Ziel die Schichtqualität und die Mikrostruktur um Fehlstellen zu beschreiben. Imperfections on substrate surfaces can cause growth defects in hard coatings prepared by magnetron sputtering, leading to local loss of adhesion, higher friction, voids and corrosion at coating defects. CrN‐coatings are known for their high hardness and good wear resistance. In addition CrN‐coatings are better corrosion resistant than Ti based nitrides. The structure and the mechanical properties of those coatings can be influenced by varying bias voltage and gas flow during film growth. Due to variation of those parameters CrN‐coatings were deposited with preferred crystallized lattice orientations (111) and (200). The main objective of investigation is the potential to cover imperfections. Vickers indentations (HV 0.5) were applied as designed imperfections. As base material low alloyed steel was used (100Cr6). At first crystallized lattice orientations were identified by X‐ray diffraction (XRD). Further scanning electron microscope analysis (SEM) was applied to identify and study crystallized lattice orientations near those imperfections.