Quantitation with chemical tagging reagents in biomarker studies

Isobaric tags for relative and absolute quantitation (iTRAQ), Tandem Mass Tags (TMT) and related chemical tag reagents provide analytical platforms for quantitative proteomics applied to clinical samples. In this Viewpoint article, applications for discovery and targeted modes are discussed with an emphasis on study design and technical considerations in biomarker analysis. The evolution and promise of emerging, related strategies are also discussed. It should be noted that iTRAQ and TMT users contributed to the key debates in the biomarker field, to define strategies for biomarker discovery for identification of clinical biomarkers, and continue to inform design of verification and validation assays via implementation of non-isobaric variants for targeted analyses.     

Numerische Simulation des Verhaltens von Betontragwerken unter Brandeinwirkung

Numerical Simulation of the Response of Fire Exposed Concrete Structure The proposed numerical model for concrete and reinforced concrete structures subjected to fire comprises the transient thermal and mechanical analysis considering the temperature dependent material properties of concrete and reinforcing steel within the framework of the phenomenological approach of the Eurocode 2, part 1‐2. A concrete model, based on the combination of plasticity and damage theory, serves as the basis for the material model of concrete for high temperatures. For reinforcing steel a standard elastic‐plastic material model is employed. The proposed model is validated by the numerical simulation of fire tests on plain concrete specimens and by the numerical simulation of a large scale fire test on a reinforced concrete slab. Furthermore it is used to determine the structural integrity of a tunnel structure, put up by the cut‐and‐cover method, exposed to fire.     

Reactively formed block and graft copolymers as compatibilizers for polyamide 66/PS blends

Phthalic anhydride terminated polystyrene (PS-An) and styrene-maleic anhydride copolymer (SMA) were compared as a compatibilizer at low loadings (<10 wt%) in 70/30 polyamide 66 (PA66)/polystyrene (PS) blends. Compatibilization efficiency was judged by morphology of the blends and the extent of interfacial coupling to copolymer. Fluorescent labels of functional PS's (anthracene and pyrene for PS-An and SMA, respectively) allowed the detection of small amounts of reactively formed block (PA66-b-PS) or graft copolymer (SMA-g-PA66) in the blends via gel permeation chromatography with a fluorescence detector. Extremely fast reactions giving >60% conversion in 0.5 min mixing were observed regardless of the molecular weight, the structure, and the amount of the functional PS's. Interfacial stability of the reactively formed copolymers was estimated by micelle formation in the bulk phases and the interfacial coverage, Σ. PS-An with higher molecular weight (37 kg/mol) was most effective as a compatibilizer at the interface, showing less tendency to form microemulsions by suppressing interfacial roughening. However, a large portion of PA66-b-PS from low molecular weight PS-An (10 kg/mol) and SMA-g-PA66 from random functional SMA (16 kg/mol) migrated to the bulk phase to form micelles even at <2 wt% loadings. Blends of PA66 with syndiotactic PS compatibilized with PS-An gave very similar morphology to the PA66/PS blends indicating that these conclusions apply also to PA66/sPS blends.     

Assessment of video tone-mapping: Are cameras’ S-shaped tone-curves good enough?

The performance of video tone-mapping operators is investigated in a rating experiment using two criteria: overall quality and fidelity to real-world experience. The study includes a tone-curve used in commercial cameras, rarely considered in tone-mapping evaluation studies. The quality is measured for a range of parameter settings, revealing the importance of parameter fine-tuning and often unsatisfactory results of the default operator parameters. In order to explain what makes best performing operators better, the results are analysed in relation to image statistics and the characteristics of the tone-mapping function. Our observations are: state-of-the-art tone mapping produces measurably better results than camera’s S-shaped curve for high dynamic range scenes with important content spanned across a wide dynamic range; differences in colour reproduction strongly affect the results; fidelity and quality criteria produce similar results when no reference is present; and state-of-the-art operators produce the results of comparable quality when their parameters are well selected.     

Duration of wood preweathering: Effect on the service life of subsequently applied paint

Previous studies of the effect of preweathering of wood (weathering of wood prior to painting) on subsequent paint performance have not linked short periods of preweathering (weeks) to paint service life. To examine the link between preweathering and paint service life, we analyzed paint performance (cracking and flaking) after 14 years outside on boards that were preweathered for various amounts of time. We then compared our results with previous results from paint adhesion tests of similar boards that were also preweathered for the same amount of time. There was a direct correlation between the amount of time the siding was preweathered and the long-term performance of paint. Paint on wood preweathered for 16 weeks began to fail after just three years. Paint on wood preweathered for shorter periods lasted longer, but even those boards that were preweathered for as little as one week showed paint failure earlier than boards that were not preweathered. There was also good correlation between paint adhesive strength results from the previous study and outdoor paint performance results from this study, showing that loss of paint adhesion may be linked to paint performance in outdoor field tests. Forest Products Laboratory, One Gifford Pinchot Dr., Madison, WI 53705-2398.     

Sanierungsforschung in regional kontaminierten Aquiferen (SAFIRA) – 1. Information zum Forschungsschwerpunkt am Standort Bitterfeld

Ziel des SAFIRA-Projektes (SAnierungs-Forschung In Regional kontaminierten Aquiferen) ist es, innovative Technologien zur In-situ-Sanierung komplex belasteter Grundw?sser zu entwickeln. Für die Untersuchungen wurde Bitterfeld als Modellstandort ausgew?hlt. An den dortigen Altstandorten der Chemieindustrie ist das Grundwasser mit aliphatischen und aromatischen chlorierten Kohlenwasserstoffen (CKW) hohen Konzentrationen kontaminiert. In einer Pilotanlage werden unter kontrollierten In-situ-Bedingungen neue Verfahren für reaktive W?nde entwickelt, getestet und optimiert. Um den geeigneten Modellstandort festzulegen, wurden die geologischen und hydrogeologischen Bedingungen untersucht und verschiedene Ausbautechnologien für die In-situ-Pilotanlage ausgewertet. Vor der Anwendung der neuen Technologien im Feld wurden kleinskalige Laborstudien und Versuche in einer mobilen Testeinheit (Skale 1 m) durchgeführt. Die Technologien, welche z. Z. in den reaktiven S?ulen der Pilotanlage getestet werden, schlie?en physiko-chemische, mikrobiologische und Kombinationsverfahren ein.     

A high dynamic range rendering pipeline for interactive applications

Realistic images can be computed at interactive frame rates for Computer Graphics applications. Meanwhile, High Dynamic Range (HDR) rendering has a growing success in video games and virtual reality applications, as it improves the image quality and the player’s immersion feeling. In this paper, we propose a new method, based on a physical lighting model, to compute in real time a HDR illumination in virtual environments. Our method allows to re-use existing virtual environments as input, and computes HDR images in photometric units. Then, from these HDR images, displayable 8-bit images are rendered with a tone mapping operator and displayed on a standard display device. The HDR computation and the tone mapping are implemented in OpenSceneGraph with pixel shaders. The lighting model, together with a perceptual tone mapping, improves the perceptual realism of the rendered images at low cost. The method is illustrated with a practical application where the dynamic range of the virtual environment is a key rendering issue: night-time driving simulation.