The diverse effects of yeast on the aroma of non-sulfite added white wines throughout aging

Semi-synthetic must containing standard nutrients, a phenolic and aromatic fraction extracted from Albariño grapes and synthetic precursors of 3-mercaptohexanol (MOH) and 4-mercapto-4-pentan-2-one (MMP) were fermented with three different selected commercial S. cerevisiae yeasts. Wines were subjected to anoxic aging at 50 °C for 1, 2, 5 and 8 weeks, and their volatile composition was comprehensively determined by the analysis of 86 different aroma compounds using five different GC methods. Yeasts exert a strong influence on wine aroma throughout the whole aging period. Their effects extend beyond the well-known actions on yeast secondary metabolites, including the formation of little amounts of Strecker aldehydes or the formation of acids precursors of fruity esters, and on the enzymatic actions on the different grape aroma precursors. Additionally, yeasts influence wine aroma; first, by producing SO2 which reacts with ß-damascenone and increases Strecker aldehyde production in fermentation; second, by inducing the differential accumulation of Strecker aldehydes during anoxic aging; and third, by determining the stability of MOH, likely because of its reaction with vinylphenols or other yeast-related electrophiles

The Olfactory Threshold of Rotundone in Brandy is Ten-fold Higher than in Wine and does not Increase with the Complexity of the Matrix

Rotundone is the only known aroma compound imparting a peppery aroma to wine. Its presence hasrecently been documented in spirits, notably those aged in oak barrels. However, the sensory contributionof rotundone in such alcoholic beverages remains hard to predict, given their high ethanol level. The aimof this study was to estimate olfactory thresholds for rotundone in brandy using three different matrices.Rotundone concentrations in the unspiked samples were 50 ng/L for wine distillate and 135 ng/L for brandy,demonstrating for the first time the presence of rotundone in such spirits and a possible endogenous origin.The olfactory detection threshold was estimated at 103 ng/L in 40% (v/v) ethanol solution, while differencethresholds were 171 ng/L and 189 ng/L in fresh wine distillate and young French brandy, respectively, bothstandardised at 40% (v/v). These thresholds were 10-fold higher than in wines and did not significantlydiffer according to the complexity of the matrix. Our results, which are still preliminary and would deserveto be validated with a larger number of samples and using a higher number of panellists, open new fieldsof investigation for a deeper exploration of the concentration range of rotundone in brandies, particularlythose that underwent a longer ageing period in barrels

Atomic and molecular spectra emitted by normal liquid ⁴He excited by corona discharge

The liquid ⁴He at fixed temperature 4.2 K and different pressures up to 8 MPa was excited by corona discharge of both negative and positive polarity. Emission of He I atomic lines and He₂ molecular bands are observed. In negative corona the lines spectra show a distinct blue-shift and line-broadening, which becomes stronger with the pressure increasing. The rotational structure of molecular bands is resolved at pressures (0.1–0.2) MPa. The blue shift of the Q-branch maximum at different pressures was observed. Rotational temperature of 900 K has been estimated for the d³Σ⁺u-b³Πg molecular band. A positive corona was realized on a point anode for fewer radii of the electrode and larger voltage than in the negative corona. Electric currents in both negative and positive corona differ weakly. Spectral analysis of the radiation from the positive corona shows qualitative differences of spectral features of these discharges. The spectra observed in the positive corona have marked nonsymmetric shape. The asymmetric atomic and molecular spectra show an increased intensity of their long-length (red) wings

Towards Translational ImmunoPET/MR Imaging of Invasive Pulmonary Aspergillosis: The Humanised Monoclonal Antibody JF5 Detects Aspergillus Lung Infections In Vivo

This is the final published versionAvailable from Ivyspring International Publisher via the DOI in this recordInvasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of hematological malignancy and bone marrow transplant patients caused by the ubiquitous environmental fungus Aspergillus fumigatus. Current diagnostic tests for the disease lack sensitivity as well as specificity, and culture of the fungus from invasive lung biopsy, considered the gold standard for IPA detection, is slow and often not possible in critically ill patients. In a previous study, we reported the development of a novel non-invasive procedure for IPA diagnosis based on antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI) using a [64Cu]DOTA-labeled mouse monoclonal antibody (mAb), mJF5, specific to Aspergillus. To enable translation of the tracer to the clinical setting, we report here the development of a humanised version of the antibody (hJF5), and pre-clinical imaging of lung infection using a [64Cu]NODAGA-hJF5 tracer. The humanised antibody tracer shows a significant increase in in vivo biodistribution in A. fumigatus infected lungs compared to its radiolabeled murine counterpart [64Cu]NODAGA-mJF5. Using reverse genetics of the pathogen, we show that the antibody binds to the antigenic determinant 1,5-galactofuranose (Galf) present in a diagnostic mannoprotein antigen released by the pathogen during invasive growth in the lung. The absence of the epitope Galf in mammalian carbohydrates, coupled with the enhanced imaging capabilities of the hJF5 antibody, means that the [64Cu]NODAGA-hJF5 tracer developed here represents an ideal candidate for the diagnosis of IPA and translation to the clinical setting.This work was supported by the European Union Seventh Framework Programme FP7/2007-2013 under Grant 602820, the Deutsche Forschungsgemeinschaft (Grant WI3777/1-2 to SW), and the Werner Siemens Foundation. We thank Sven Krappman for use of the A. fumigatustdTomato strain, and acknowledge the Imaging Centre Essen (IMCES) for assistance with optical imaging of lungs

Germline MC1R status influences somatic mutation burden in melanoma

The major genetic determinants of cutaneous melanoma risk in the general population are disruptive variants (R alleles) in the melanocortin 1 receptor (MC1R) gene. These alleles are also linked to red hair, freckling, and sun sensitivity, all of which are known melanoma phenotypic risk factors. Here we report that in melanomas and for somatic C>T mutations, a signature linked to sun exposure, the expected single-nucleotide variant count associated with the presence of an R allele is estimated to be 42% (95% CI, 15-76%) higher than that among persons without an R allele. This figure is comparable to the expected mutational burden associated with an additional 21 years of age. We also find significant and similar enrichment of non-C>T mutation classes supporting a role for additional mutagenic processes in melanoma development in individuals carrying R alleles

Etude de la génération de bulles dans les hydrocarbures liquides générées par les impulsio.ns de Trichel

The electrical conduction of purified non polar liquids with point-plane electrode geometry was studied as a function of various parameters. For negative polarity of the point a pulse regime have been observed which bears a great similarity with the Trichel pulses. Below the critical pressure of the liquids, bubble formation was correlated with current pulse. In this paper we present a study of the generation and dynamics of the bubble as function of various parameters: injected energy, liquid pressure, liquid properties. The transition to a streamer phenomenon is also investigated.Une étude de la conduction électrique des liquides non polaires très purs, dans une géométrie pointe-plan, a mis en évidence l'apparition d'un régime très régulier d'impulsions de courant en polarité négative de la pointe. Ce régime s'explique par un mécanisme d'avalanches électroniques en phase liquide dans la zone de champ intense qui induit la formation d'une bulle unique. L'énergie injectée est uniquement fonction du rayon de courbure de la pointe. On présente une étude de la génération et de la dynamique de cette bulle en fonction de la nature du liquide, de la pression hydrostatique et de l'énergie injectée. On montre que la dynamique de la bulle est contrôlée par l'inertie du liquide, que sa taille maximale est proportionnelle à l'énergie injectée pour une pression donnée et que cette énergie sert essentiellement à vaporiser le liquide. Dans les conditions où la durée de vie de la bulle et donc sa taille sont élevées, l'impulsion initiale de courant est suivie par des décharges électriques dans la bulle et il y a début de propagation d'un canal gazeux vers le plan (streamer !)

Light emission from corona discharge in SF

A spectroscopic investigation of corona discharges in SF6/N2 gas mixtures has been undertaken using an optical multichannel analyser (OMA). A point-to-plane geometry has been used with point radii varying from 3 to 10 μm. Spectra are measured for high pressures ranging from 0.2 MPa up to 1.4 MPa and for different concentrations of SF6 in the gas mixture. The spectra in the 200–850 nm spectral range are mainly made of molecular bands, which is indicative of a low temperature discharge. It has been noted that SF6 emits in the region of 420 nm to 510 nm in positive and negative polarities, although in negative polarity the emission is weaker. For SF6/N2 mixtures, the main source of light emission is from N2. The resultant spectra are used to evaluate the rotational Tr and vibrational Tv temperatures of excited N2, Tr being considered, due to the high pressure, to be equal to the kinetic temperature Tkin in the corona discharge. Tr and Tv are determined by comparing the experimental spectrum of the second positive system ($C^{3}\Pi_{u}\to B^{3}\Pi_{g})$ of N2 and the simulated one, which is obtained using a convolution method. As expected, the results show that the measured rotational temperature Tr increases steadily with the mean discharge current, while its increase with gas pressure is less pronounced. The values of Tr are higher for the positive corona discharge than the negative and also for mixtures having higher amounts of SF6. In all conditions, we found $T_{v}>T_{r}$ and Tv is less sensitive to the variation of the current