Underwater Adhesives Produced by Chemically Induced Protein Aggregation

Barnacles convert hydrophilic proteins into an insoluble, yet aqueous, material that functions as a permanent underwater adhesive. Here, it is demonstrated that a common hydrophilic protein, bovine serum albumin, can be chemically triggered underwater to aggregate into a similar aqueous adhesive that mimics the formation of the natural adhesive. The combined action of multiple chemical denaturants initiates rapid gelation followed by further curing over time in artificial seawater. The adhesive strengths of this waterborne adhesive measured by lap shear are comparable to many bioinspired adhesives that use organic solvents and a high fraction of hydrophobic components. This approach establishes a bioinspired adhesive that can be deployed at practical scales in marine environments, produced sustainably, and sourced from low-cost materials.     

A Covalent Cysteine‐Targeting Kinase Inhibitor of Ire1 Permits Allosteric Control of Endoribonuclease Activity

The unfolded protein response (UPR) initiated by the transmembrane kinase/ribonuclease Ire1 has been implicated in a variety of diseases. Ire1, with its unique position in the UPR, is an ideal target for the development of therapies; however, the identification of specific kinase inhibitors is challenging. Recently, the development of covalent inhibitors has gained great momentum because of the irreversible deactivation of the target. We identified and determined the mechanism of action of the Ire1‐inhibitory compound UPRM8. MS analysis revealed that UPRM8 inhibition occurs by covalent adduct formation at a conserved cysteine at the regulatory DFG+2 position in the Ire1 kinase activation loop. Mutational analysis of the target cysteine residue identified both UPRM8‐resistant and catalytically inactive Ire1 mutants. We describe a novel covalent inhibition mechanism of UPRM8, which can serve as a lead for the rational design and optimization of inhibitors of human Ire1.     

Quasi-One-Dimensional Natures in (Et n Me4−n Z)[Pd(dmit)2]2

We studied one of possible ground states for Pd(dmit) ₂ salts in a dimerized two-band Hubbard model. By using a strong-coupling expansion, we obtained an effective dimer model which has a quasi-one-dimensional Fermi surface. In the insulating phase, it leads to the Heisenberg model on an anisotropic triangular lattice. We calculated effective exchange coupling strengths within the second order perturbation theory and found that both ferromagnetic and antiferromagnetic couplings are possible. Similarities to and differences from Ni(dmit) ₂ salts are discussed.     

Interactions between citizen responsibilization,flood experience and household resilience: insights from the 2013 flood in Germany

As increasing emphasis is placed on the importance of citizens’ taking responsibility for their own preparedness and protection against flooding, it is important to understand the relationship between responsibility and action and how current practices of responsibilization influence household resilience. Based on a survey of 889 households affected by flooding in 2013 in the states of Saxony and Bavaria, Germany, this study investigates the relationship between action and flood experience and how this experience influences whether citizens feel responsible, and therefore the likelihood that they will take action in the future. These findings have implications for household resilience as well as future research.     

Global Deletion of 11β-HSD1 Prevents Muscle Wasting Associated with Glucocorticoid Therapy in Polyarthritis

Glucocorticoids provide indispensable anti-inflammatory therapies. However, metabolic adverse effects including muscle wasting restrict their use. The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) modulates peripheral glucocorticoid responses through pre-receptor metabolism. This study investigates how 11β-HSD1 influences skeletal muscle responses to glucocorticoid therapy for chronic inflammation. We assessed human skeletal muscle biopsies from patients with rheumatoid arthritis and osteoarthritis for 11β-HSD1 activity ex vivo. Using the TNF-α-transgenic mouse model (TNF-tg) of chronic inflammation, we examined the effects of corticosterone treatment and 11β-HSD1 global knock-out (11βKO) on skeletal muscle, measuring anti-inflammatory gene expression, muscle weights, fiber size distribution, and catabolic pathways. Muscle 11β-HSD1 activity was elevated in patients with rheumatoid arthritis and correlated with inflammation markers. In murine skeletal muscle, glucocorticoid administration suppressed IL6 expression in TNF-tg mice but not in TNF-tg^11βKO mice. TNF-tg mice exhibited reductions in muscle weight and fiber size with glucocorticoid therapy. In contrast, TNF-tg^11βKO mice were protected against glucocorticoid-induced muscle atrophy. Glucocorticoid-mediated activation of catabolic mediators (FoxO1, Trim63) was also diminished in TNF-tg^11βKO compared to TNF-tg mice. In summary, 11β-HSD1 knock-out prevents muscle atrophy associated with glucocorticoid therapy in a model of chronic inflammation. Targeting 11β-HSD1 may offer a strategy to refine the safety of glucocorticoids.     

Kevlar®对位芳纶浆粕增强橡胶的研究

研究Kevlar对位芳纶浆粕和精切短纤维对天然橡胶胶料的补强效果。结果表明:随着纤维用量的增大,Kevlar对位芳纶浆粕补强的胶料储能模量增加幅度大于损耗模量增加幅度,损耗角和损耗因子随着浆粕用量的增大而降低,这种效果有利于低滚动阻力轮胎或其他轮胎部件的胶料配方设计,在提高胶料定伸模量的同时不会增加滞后生热;Kevlar对位芳纶浆粕表现出的一种独特手风琴效应可能是低滞后生热的原因。     

Military (in)decision-making process: a psychological framework to examine decision inertia in military operations

Abstract

When understanding how members of the armed forces make decisions in war current military doctrine centers on the military decision-making process (MDMP) – a linear process of identifying, evaluating and choosing the best course of action, while wider theoretical contributions focus on recognition prime models (RPD) of decision-making. In this article, we argue that the SAFE-T model of critical incident decision-making can elucidate the process of decision-making during military operations. The SAFE-T model states that effective decision-making follows a sequential process of situation assessment (SA), plan formulation (F) and plan execution (E) phases, and team learning (T). The central innovation of the SAFE-T model; however, is that it highlights the different ways in which decision-making can de-rail from this optimal strategy, resulting in decision inertia. This article discusses the implications of employing the SAFE-T model as a framework to study military decision-making both in the lab and in the field.     

Dynamic mechanical relaxation of cross-linked styrene-butadiene polymers containing free chains: Possibility of reptation

The structure of styrene-butadiene rubbers (SBRs) consists of chains attached to cross-links of relatively small number density. These rubbers show an α-relaxation process that is attributed to segmental motions of the attached chains. To investigate how an SBR's rubber-like behavior would change when free chains interpenetrate its structure, we prepared one SBR of mol wt 120 × 10³ containing 3–4% free chains of identical mol wt, and studied its dynamic mechanical relaxation. For 0.1 Hz frequency measurements, the α-relaxation peak appeared at 210 K, and a second relaxation peak, which we refer to as α_R-relaxation, at 300 K. A third relaxation of small magnitude was resolved at temperatures between the α_R- and the α-relaxation peaks, and its origin was discussed in relation to other studies. Spectral features of the α_R-and the α-relaxations were found similar. We investigated the merits of the time-temperature superposition of the α- and of the α_R-relaxations. The α_R relaxation vanished when the free chains were extracted from the SBR by swelling-extraction procedure. The features of α-relaxation can be interpreted as segmental motions of the SBR, but the features of the α_R-relaxation is be interpretable only in terms of tube model for diffusion of free chains in a lightly cross-linked structure. We estimated the mol wt of these free chains and the mass between entanglements, and then used these quantities to calculate, by using the Doi-Edwards formalism, the relaxation time of the α_R-process at 293 K. This relaxation time agrees with the experimental value. The α_R-relaxation seems consistent with the tube model for diffusion of free chains in the cross-linked structure of SBR.