110 research outputs found

    A Flight Evaluation of a VTOL Jet Transport Under Visual and Simulated Instrument Conditions

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    Transition, approach, and vertical landing tests for VTOL transport in terminal are

    Discovery and Characterization of Protein-Modifying Natural Products by MALDI Mass Spectrometry Reveal Potent SIRT1 and p300 Inhibitors

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    A straightforward MALDI MS method facilitates the unbiased screening and characterization of compounds that modify protein activity. This procedure can be used to circumvent analytical problems deriving from compounds with autofluorescence. Various posttranslationally active enzymes like deacetylases, acetyltransferases, kinases, phosphatases, and methyltransferases can be studied in the presented way

    Peptidomics characterization of allergenic and non-allergenic tropomyosin orthologs

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    Background The cleavage and the digestion patterns of allergenic proteins play a key role in allergenicity. The transformation of food proteins starts with their denaturation by the acidic environment of the stomach. However, protein denaturation is not enough to completely remove allergenic properties of a protein, but it is necessary a complete enzymatic digestion. Whether the enzymatic digestion is not efficient, the persistence of bigger peptides can occur and put the basis for the development of the sensitization process.The hypothesis of the current work takes into consideration the probability that shrimp tropomyosin (TM) is not fully digested or presents a digestion pattern that generates some peptides that can be immunogenic.Therefore, the work plan designed, aims to study the cleavage pattern of: purified chicken TM, recombinant chicken TM, purified TM of Penaeus monodon (Pen m 1), recombinant TM of Penaeus monodon (rPen m 1) and recombinant TM of Crangon crangon (rCrac c 1). Methods One mg of each ortholog has been processed through simulated mouth, gastric and intestinal digestion. The sample was frozen to block the digestion and, after this step, concentrated and cleaned through protein precipitation. The protein pellet was processed for peptidomic analysis through 1D Tricine gel electrophoresis, 2D Tricine gel electrophoresis and mass spectrometry. Results Simulated gastric digestion pattern of shrimp TM highlighted the presence of a resistant band at an average MW of 25 kDa that could be involved in the immunogenic process. Conclusions This innovative approach (peptidomics study through 1D-2D Tricine/MS) could represent a milestone for the study of digestion patterns of allergenic proteins or for the study of allergenic potential of novel foods

    Standardization of double blind placebo controlled food challenge with soy within a multicentre trial

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    Background: Multicentre trials investigating food allergies by double blind placebo controlled food challenges (DBPCFC) need standardized procedures, challenge meals and evaluation criteria. We aimed at developing a standardized approach for identifying patients with birch related soy allergy by means of DBPCFC to soy, including determination of threshold levels, in a multicentre setting. Methods: Microbiologically stable soy challenge meals were composed of protein isolate with consistent Gly m 4 levels. Patients sensitized to main birch allergen Bet v 1 and concomitant sensitization to its soy homologue Gly m 4 underwent DBPCFC. Outcome was defined according to presence and/or absence of ten objective signs and intensity of eight subjective symptoms as measured by visual analogue scale (VAS). Results: 138 adult subjects (63.8% female, mean age 38 years) underwent DBPCFC. Challenge meals and defined evaluation criteria showed good applicability in all centres involved. 45.7% presented with objective signs and 65.2% with subjective symptoms at soy challenge. Placebo challenge meals elicited non-cardiovascular objective signs in 11.6%. In 82 (59.4%) subjects DBPCFC was judged as positive. 70.7% of DPBCFC+ showed objective signs and 85.4% subjective symptoms at soy challenge. Subjective symptoms to soy challenge meal in DBPCFC+ subjects started at significantly lower dose levels than objective signs (p < 0.001). Median cumulative eliciting doses for first objective signs in DBPCFC+ subjects were 4.7 g [0.7–24.7] and 0.7 g [0.2–4.7] total soy protein for first subjective symptoms (p = 0.01). Conclusions: We present the hitherto largest group of adults with Bet v 1 and Gly m 4 sensitization being investigated by DBPCFC. In this type of food allergy evaluation of DBPCFC outcome should not only include monitoring of objective signs but also scoring of subjective symptoms. Our data may contribute to standardize DBPCFC in pollen-related food allergy in multicentre settings. Trial registration EudraCT: 2009-011737-27

    The 10Be deglaciation chronology of the Göschenertal, central Swiss Alps, and new insights into the Göschenen Cold Phases

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    The Göschenertal (Göschenen valley) is the type locality of the so‐called Göschenen Cold Phases I (~3–2.3 ka) and II (~1.8–1.1 ka). According to earlier studies, these Late Holocene climatic cooling periods were characterized by changes in vegetation and pronounced glacier advances. As a peculiarity, the Göschenen Cold Phase I was thought to be connected to a local surge‐type advance of the Chelengletscher (Chelen glacier) – an exceptional event of unparalleled dimension in the European Alps. Based on cosmogenic 10Be exposure ages from moraine boulders, we investigated the local glacier chronology. In contrast to former research, moraines at different positions within the Göschenen valley (central Swiss Alps) have been dated to the Younger Dryas and the Early Holocene. This questions the applicability of palaeo‐Equilibrium Line Altitude (ELA) calculations for stadial attributions without additional numerical age constraints. Furthermore, we have found compelling evidence that the proposed non‐climatic glacier advance attributed to the Göschenen Cold Phase I did not occur. The present results, along with a reappraisal of the original study, question the scientific reliability and the glaciological definition of the Göschenen Cold Phases as glacier advances that clearly exceeded the Little Ice Age positions. While our data do not exclude potential changes in climate and vegetation, we nonetheless show that the Göschenen Cold Phases are not suitable as reference stadials in the system of Alpine Holocene glacier fluctuations

    Impact of Leather on the Fire Resistance of Leather-Wood Fibreboard: FT-IR Spectroscopy and Pyrolysis-GC-MS Investigation

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    Leather-wood fibreboards are innovative composite materials, which combine together the high mechanical properties of wood with the superior fire behaviour properties of leather. This study deals with the understanding of the combustion mechanism of the wet-white leather panel. During burning, an overlay coating-like surface is formed on top of a foamy structure that creates the heat transfer barrier. The FT-IR spectroscopy results of the leather show the rearrangement of the proteins and the formation of an increasing amount of acid groups when the exposure to hot gun at over 530°C was prolonged. These acid moieties can react with amino groups of other peptide chains, building a protective polymer network which hinders the oxygen to reach the core of the panel. Simultaneously, the gases produced during rearrangement cannot easily leave the material, producing a foamy structure which slows down the heat transfer to the core of the material. The Py-GC-MS analysis shows that the gases produced by the wet-white leather-type protein-based boards were amino-aromatic compounds like the diketopiperazine (DKP), which do not burn easily. The combination of the effects of (i) formation of the overlay coating-like surface, (ii) establishment of the foamy structure, and (iii) degassing of DKP explains the outstanding fire properties of leather and wood-leather fibreboards

    RNA “Traffic Lights”: An Analytical Tool to Monitor siRNA Integrity

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    The combination of thiazole orange and thiazole red as an internal energy transfer-based fluorophore pair in oligonucleotides provides an outstanding analytical tool to follow DNA/RNA hybridization through a distinct fluorescence color change from red to green. Herein, we demonstrate that this concept can be applied to small interfering RNA (siRNA) to monitor RNA integrity in living cells in real time with a remarkable dynamic range and excellent contrast ratios in cellular media. Furthermore, we show that our siRNA-sensors still possess their gene silencing function toward the knockdown of enhanced green fluorescent protein in CHO-K1 cells
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