SkaSim – Skalierbare HPC‐Software für molekulare Simulationen in der chemischen Industrie

This article outlines advances in molecular modeling and simulation using massively parallel high‐performance computers (HPC). In the SkaSim project, partners from the HPC community collaborated with users from science and industry. The aim was to optimize the prediction of thermodynamic property data in terms of efficiency, quality and reliability using HPC methods. In this context, various topics were dealt with: atomistic simulation of homogeneous gas bubble formation, surface tension of classical fluids and ionic liquids, multicriteria optimization of molecular models, the development of the molecular simulation codes ls1 mardyn and ms2, atomistic simulation of gas separation processes, molecular membrane structure generators, transport resistors and the evaluation of predictive property data models based on specific mixture types.     

Blends of Two Perylene Derivatives: Mesogenic Properties and Application As Emitter Materials in OLEDs

Blends consisting of two components, namely a liquid crystalline perylene ester and a bilaterally extended perylene ester, were studied. The liquid crystalline properties of these blends were investigated in detail by means of polarized optical microscopy and differential scanning calorimetry. The resulting phase diagram was used to explore the potential of these blends as emitter layers in OLEDs, which were prepared via thermal evaporation in a vacuum and spin coating of solutions.     

Wood‐Plastic‐Composites: Rheologische Charakterisierung und Füllverhalten im Spritzgießprozess

Wood‐plastic composites (WPC) show a complex and completely different material and flow behavior in comparison to pure polymers. Especially the flow behavior is very important for the processing of these composites. In the following article results of rheological characterization and investigations of the filling behavior during the injection molding process are presented. Furthermore, appearing challenges and possible methods of resolution are discussed.     

Post‐protection effect of heat‐resistant insulations on timber‐frame members exposed to fire

In lightweight walls and floors, the load‐bearing timber members are protected by cladding on the sides to form a divider between two fire compartments or to provide appropriate fire protection to the load‐bearing members. The spaces between the timber members can be void or filled with insulation materials. Although a huge number of different insulation materials exist, the most commonly used material is mineral wool insulation. The existing design model for glass wool‐insulated timber‐frame constructions, given in European standard 1995‐1‐2, assumes collapse of the glass wool after failure of the cladding. However, a new form of glass wool insulation, suitable for use at high maximum service temperatures, is now available in the market. The charring phase after the cladding's failure is known as the post‐protection phase. The behaviour of the new heat‐resistant glass wool in the post‐protection phase is similar to that of stone wool and considerably better than that of traditional glass wool. The protective properties of stone wool have changed over the last decades. Charring is one of the main parameters needed to calculate the resistance of a structure to fire. Based on experimental investigations, this paper describes the analysis of the effect of the insulation with regard to its ability to protect timber members against charring during the post‐protection phase. Copyright © 2011 John Wiley & Sons, Ltd.     

Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial

Background

Probiotics are an upcoming group of nutraceuticals claiming positive effects on athlete??s gut health, redox biology and immunity but there is lack of evidence to support these statements.

Methods

We conducted a randomized, double-blinded, placebo controlled trial to observe effects of probiotic supplementation on markers of intestinal barrier, oxidation and inflammation, at rest and after intense exercise. 23 trained men received multi-species probiotics (10¹⁰ CFU/day, Ecologic?Performance or OMNi-BiOTiC?POWER, n?=?11) or placebo (n?=?12) for 14?weeks and performed an intense cycle ergometry over 90 minutes at baseline and after 14?weeks. Zonulin and ??1-antitrypsin were measured from feces to estimate gut leakage at baseline and at the end of treatment. Venous blood was collected at baseline and after 14?weeks, before and immediately post exercise, to determine carbonyl proteins (CP), malondialdehyde (MDA), total oxidation status of lipids (TOS), tumor necrosis factor-alpha (TNF-??), and interleukin-6 (IL-6). Statistical analysis used multifactorial analysis of variance (ANOVA). Level of significance was set at p?<?0.05, a trend at p?<?0.1.

Results

Zonulin decreased with supplementation from values slightly above normal into normal ranges (<30?ng/ml) and was significantly lower after 14?weeks with probiotics compared to placebo (p?=?0.019). We observed no influence on ??1-antitrypsin (p?>?0.1). CP increased significantly from pre to post exercise in both groups at baseline and in the placebo group after 14?weeks of treatment (p?=?0.006). After 14?weeks, CP concentrations were tendentially lower with probiotics (p?=?0.061). TOS was slightly increased above normal in both groups, at baseline and after 14?weeks of treatment. There was no effect of supplementation or exercise on TOS. At baseline, both groups showed considerably higher TNF-?? concentrations than normal. After 14?weeks TNF-?? was tendentially lower in the supplemented group (p?=?0.054). IL-6 increased significantly from pre to post exercise in both groups (p?=?0.001), but supplementation had no effect. MDA was not influenced, neither by supplementation nor by exercise.

Conclusions

The probiotic treatment decreased Zonulin in feces, a marker indicating enhanced gut permeability. Moreover, probiotic supplementation beneficially affected TNF-?? and exercise induced protein oxidation. These results demonstrate promising benefits for probiotic use in trained men.

Clinical trial registry

http://www.clinicaltrials.gov, identifier: NCT01474629     

Matrix Transformation in Boron Containing High-Temperature Co–Re–Cr Alloys

An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr₂Re₃ type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content.     

Evaluation and simulation of the peel behavior of polyethylene/polybutene‐1 peel systems

The peel characteristics of sealed low‐density polyethylene/isotactic polybutene‐1 (PE‐LD/iPB‐1) films, with different contents of iPB‐1 up to 20 m.‐% (mass percentage), were evaluated and simulated in dependence on the iPB‐1 content, and in dependence on the peel rate. Sealing involves close contact and localized melting of two films for a few seconds. The required force, to separate the local adhered films, is the peel force, which is influenced, among others, by the content of iPB‐1. The peel force decreases exponentially with increasing iPB‐1 content. Transmission electron microscopy studies reveal a favorable dispersion of the iPB‐1 particles within the seal area, for iPB‐1 concentrations ≥6 m.‐%. Here, the iPB‐1 particles form continuous belt‐like structures, which lead to a stable and reproducible peel process. The investigation of the peel rate‐dependency on the peel characteristics is of important interest for practical applications. The peel force increases with increasing peel rate by an exponential law. A numerical simulation of the present material system proves to be useful to comprehend the peel process, and to understand the peel behavior in further detail. Peel tests of different peel samples were simulated, using a two‐dimensional finite element model, including cohesive zone elements. The established finite element model of the peel process was used to simulate the influence of the modulus of elasticity on the peel behavior. The peel force is independent of the modulus of elasticity, however, the peel initiation value increases with increasing modulus of elasticity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Screening for Cytochrome P450 Reactivity by Harnessing Catalase as Reporter Enzyme

The big screen : We have devised a high‐throughput screening method for organic peroxide‐dependent P450 reactivity by taking advantage of a previously undescribed activity of catalase, which was used as reporter enzyme. This two‐step assay, followed by liquid chromatography/mass spectrometry analyses, allowed the facile identification of several new substrates for bacterial P450 enzymes.

     

Discovery of Riociguat (BAY 63‐2521): A Potent,Oral Stimulator of Soluble Guanylate Cyclase for the Treatment of Pulmonary Hypertension

Direct stimulation of soluble guanylate cyclase (sGC) represents a promising therapeutic strategy for the treatment of a range of diseases, including the severely disabling pulmonary hypertension (PH). Optimization of the unfavorable DMPK profile of previous sGC stimulators provided riociguat, which is currently being investigated in phase III clinical trials for the oral treatment of PH.