284 research outputs found
Phonons and structures of tetracene polymorphs at low temperature and high pressure
Crystals of tetracene have been studied by means of lattice phonon Raman
spectroscopy as a function of temperature and pressure. Two different phases
(polymorphs I and II) have been obtained, depending on sample preparation and
history. Polymorph I is the most frequently grown phase, stable at ambient
conditions. A pressure induced phase transition, observed above 1 GPa, leads to
polymorph II, which is also obtained at temperatures below 140 K. Polymorph II
can also be maintained at ambient conditions.
We have calculated the crystallographic structures and phonon frequencies as
a function of temperature, starting from the configurations of the energy
minima found by exploring the potential energy surface of crystalline
tetracene. The spectra calculated for the first and second deepest minima match
satisfactorily those measured for polymorphs I and II, respectively. All
published x-ray structures, once assigned to the appropriate polymorph, are
also reproduced.Comment: 8 pages, 5 figures, RevTeX4, update after referees report
Profile of red wine partially dealcoholized with a membrane-based technique and strategies to mitigate the loss of volatile compounds
: In recent years, climate change has led to higher grape must sugar content and, consequently, increased alcohol by volume. Evaporative or pertraction is a common method for post-fermentation ethanol removal from wines, but it selectively removes some less polar volatile compounds along with ethanol. To mitigate volatile substance loss, this study investigates blending of the red wine (Marzemino-Cabernet blend) with obtained dealcoholized samples from it by industrial evaporative pertraction system, while maintaining the final product within a two-percentage-point reduction in ethanol. Thus MIX 1 and MIX 2 blends were prepared, reducing the ABV of the initial wine (12.5% alcohol by volume) to 10.5% and 9.5%. Chemical analyses highlighted that most alcohols, acetates, and ethyl esters of fatty acids decreased with alcohol by volume reduction. However, compounds with polar groups (acetoin and acetovanillone), C13-norisoprenoids, and certain lactones showed increasing trends. Sensory analysis indicated high scores for sweetness and smoothness in the blended wines, with a decrease in acidic taste. Floral scents notably increased, particularly in MIX 2, closely resembling the initial wine's sensory profile. The blending of initial wine with appropriately dealcoholized wine samples has proven to be an effective strategy for preserving bouquet and color of dealcoholized wines. This approach broadens the consumer base by catering to people who prefer low-alcohol options, have dietary restrictions, or are health-conscious, but who still wish to savor wines with aromatic quality rather than a flat taste. This strategy is crucial in the wine industry as it successfully addresses technical challenges and ensures economic viability
Effect of Kaolin/Defoliation Combined with Dry Ice on Lambrusco Red Wine Production to Constrain the Effects of Climate Change
Since viticulture is affected considerably by climate change, it is imperative to encourage research on newstrategies in order to constrain these critical effects on the composition of berries and the quality of wines.A multi-strategy approach composed of (i) kaolin application on foliage, (ii) late tree defoliation and (iii)cryomaceration of grapes with dry ice was evaluated in the production of Lambrusco Salamino wines.Physical, chemical and sensory analyses were carried out on the sample set, including the control wines.In general, cryomaceration with dry ice proved to be a winning choice to lower alcoholic strength (roughly5%). In addition, the wines showed an increase in anthocyanin content by approximately 17%, while thecontent of catechins, flavanols and hydroxycinnamic acids decreased. Consistent with the increase in theanthocyanin content, an increase in colour indices and sensory colour intensity scores was observed. As forthe aromatic profile, 2-phenylethanol showed an increase of approximately 18% in the treated wines while,in parallel, a lower content of C6 alcohols and volatile fatty acids was observed. The multiple adaptationstrategies put in place in the present study show an alternative way to mitigate the severe effects of climatechange on wine production, and to face changing consumer demands
Role of Multiparametric-MRI in Bladder Cancer
Purpose of ReviewThis narrative review article aims to show the actual role of imaging, in particular MRI, and the role of VI-RADS Score, in recognition and follow-up of the tumor.Recent FindingsA team of professionals created VI-RADS with the goal of standardizing the acquisition and interpretation of multiparametric-MRI in bladder cancer.Bladder cancer is the most common cancer involving the urinary system. It is the fourth most common urological cancer in men and the second most frequent cancer affecting the urinary tract. Main risks factors are advanced age, male sex, and cigarette smoking. Bladder cancer ranges from unaggressive and usually non-invasive tumors that recur and commit patients to long-term invasive surveillance, to aggressive and invasive tumors with high disease-specific mortality. At the time of diagnosis, 70% of patients are experiencing non-muscle-invasive bladder cancer. Vesical imaging-reporting and data system score (VI-RADS) is a scoring system useful to standardize the approach to multiparametric-MRI interpretation, and reporting for bladder cancer
On the mechanism of calcium-dependent activation of NADPH oxidase 5 (NOX5)
It is now accepted that reactive oxygen species (ROS) are not only dangerous oxidative agents but also chemical mediators of the redox cell signaling and innate immune response. A central role in ROS-controlled production is played by the NADPH oxidases (NOXs), a group of seven membrane-bound enzymes (NOX1-5 and DUOX1-2) whose unique function is to produce ROS. Here, we describe the regulation of NOX5, a widespread family member present in cyanobacteria, protists, plants, fungi, and the animal kingdom. We show that the calmodulin-like regulatory EF-domain of NOX5 is partially unfolded and detached from the rest of the protein in the absence of calcium. In the presence of calcium, the C-terminal lobe of the EF-domain acquires an ordered and more compact structure that enables its binding to the enzyme dehydrogenase (DH) domain. Our spectroscopic and mutagenesis studies further identified a set of conserved aspartate residues in the DH domain that are essential for NOX5 activation. Altogether, our work shows that calcium induces an unfolded-to-folded transition of the EF-domain that promotes direct interaction with a conserved regulatory region, resulting in NOX5 activation
The step-down approach in children with cow's milk allergy: Results of a randomized controlled trial
Background: The Step-Down Approach for Cow's Milk Allergy (SDACMA) trial evaluated the tolerability and the rate of immune tolerance acquisition in CMA children starting dietary treatment with amino acid-based formula (AAF) and then switching to EHCF containing the probiotic Lacticaseibacillus rhamnosus GG (EHCF + LGG). Methods: Randomized controlled trial involving IgE-mediated CMA children receiving AAF from at least 4 weeks. EHCF + LGG tolerance was evaluated by the results of double-blind placebo-controlled food challenge (DBPCFC). Subjects tolerating EHCF + LGG were randomly allocated to remain on AAF, or to switch to EHCF + LGG. Immune tolerance acquisition to cow's milk proteins was evaluated with DBPCFC after 12 months of treatment. Allergy screening tests and body growth were also monitored. Results: Sixty IgE-mediated CMA children were enrolled. The proportion of children treated with AAF who resulted tolerant to the first exposure of EHCF + LGG was 0.98 (exact 95% CI 0.91–0.99). The rate of the immune tolerance acquisition to cow milk proteins after 12 months treatment was higher in the EHCF + LGG (0.48, 95% exact CI 0.29–0.67, n/N = 14/29) than in the AAF group (0.03, 95% exact CI 0.001–0.17, n/N = 1/30). There was an absolute benefit increase (ABI) of tolerance rate equal to 0.45 (95% CI 0.23–0.63, Newcombe method 10) for EHCF + LGG versus AAF, corresponding to a NNT of 2 (2–4, Bender's method). A normal body growth pattern was observed in the two study groups. Conclusion: In IgE-mediated CMA children the step-down from AAF to EHCF + LGG is well tolerated and could facilitate the immune tolerance acquisition
Seasonal variability of the HO.RE.CA. food leftovers employed as a feeding substrate for black soldier fly (Hermetia illucens L.) larvae and effects on the rearing performance
The SCALIBUR project (Horizon, 2020) aimed to explore innovative solutions, including the use of black soldier fly larvae, for the bio-urban waste management. This research work describes the evaluation of the variability in water, proteins, fat, ashes, and carbohydrates present in the HO.RE.CA. food leftovers which were withdrawn from a local canteen over a 12-month period and the relationship with (i) the growth parameters of the larvae, (ii) the percentage of substrate reduction and the percentage of frass separated through the mechanical sieve at the end of the rearing process. HO.RE.CA. food leftovers are overall a suitable feeding substrate for larval rearing. Water contained in the HO.RE.CA. food leftovers was sufficient for larval rearing without resorting to further addition. As for water content, a seasonal trend was not observed, on the contrary, it was proved to be totally random. However, high amount of water (>80%) was correlated with higher larval mortality rate. The larval weight was significantly correlated to the amount of protein (r = 0.80; p ≤ 0.001) present in the substrate, and to a lesser extent to the amount of fat (r = 0.43; p ≤ 0.05). The feed conversion rate and bioconversion rate were both in agreement with literature data. The statistical test did not show any significant correlation between the amount of water contained in the initial fresh HO.RE.CA. food leftovers and the percentage of substrate reduction and the percentage of frass separated through the mechanical sieve at the end of the rearing process
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