Changes in the volatile composition of red wines during aging in oak barrels due to microoxygenation treatment applied before malolactic fermentation

Microoxygenation is a wine-making technique consisting in the addition of small and controlled amounts of oxygen. This study has examined the effect of this technique on the volatile composition of two red single variety wines during two successive vintages. The microoxygenation treatment was applied at the end of alcoholic fermentation and before beginning malolactic fermentation. Once the microoxygenation treatment had finished, wines were aged in new American oak barrels for 12 months. The results obtained showed that the microoxygenation treatment did not cause significant changes in the varietal and fermentation volatile compounds, however microoxygenation slowed down the extraction of some of the volatile compounds extracted from wood. A varietal and vintage effect was also observed for some of the compounds studied.     

Antioxidant potential of single-variety red wines aged in the barrel and in the bottle

Wine constitutes a dynamic system in continuous evolution, in which numerous reactions involving polymerization and condensation take place between its phenolic compounds during the ageing process, which undoubtedly affect its structure and, very probably, its antioxidant effect. This study set out to evaluate the effect of ageing on the antioxidant potential of wine. A group of 162 wines were studied, of varying ages, which had undergone different ageing processes, both in the barrel and in the bottle, and which were prepared from different grape varieties and vintages. Total antioxidant capacity (ABTS, DPPH, DMPD, ORAC and FRAP), scavenger activity (HRSA and SRSA) and the biomarkers of oxidative stress (DNA-damage and ABAP-LP) were all analysed. The assay methods showed different behaviours for the same wines, thus the young wines presented higher indices for ABTS, DPPH and DMPD, whereas those that were aged showed higher indices for ABAP-LP and ORAC. Finally, the antioxidant potential of the wines in the study appeared not to be influenced by other factors, such as microoxygenation or grape variety.     

Colloidal synthesis of Au nanoparticles using polyelectrolytes with 1,3,4-thiadiazole as reducing agents

Heterocyclic compounds are well known for their biological activity and coordination properties. Some heterocyclic compounds have been employed in the stabilization against coalescence of metallic nanoparticles in colloidal solutions, for example, tetrazole, triazole, and pyrazole. The aim of this work is to design new polyelectrolytes with heterocyclic pendant groups useful as reducing agents of Au³⁺ and as stabilizing agents for the synthesis of colloidal Au nanoparticles. Thus, polyelectrolytes with thiosemicarbazone and 1,3,4-thiadiazole pendant groups were used as reducing agents of Au³⁺ ions and stabilizing agents of Au nanoparticles. The voltammetry study of the polyelectrolytes showed that one with thiosemicarbazone pendant groups is the better reducing agent than polyelectrolytes with heterocyclic pendant groups. The polyelectrolytes can control the growth of the nanoparticles, obtaining structures with an average size of 9 nm. In this study, it was concluded that the nature of the heterocyclic group does not have an effect on the shape of nanoparticles and quasi-spherical nanoparticles were obtained with all polyelectrolytes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47790.     

Interrelated Mechanism by Which the Methide Quinone Celastrol,Obtained from the Roots of Tripterygium wilfordii,Inhibits Main Protease 3CLpro of COVID-19 and Acts as Superoxide Radical Scavenger

We describe the potential anti coronavirus disease 2019 (COVID-19) action of the methide quinone inhibitor, celastrol. The related methide quinone dexamethasone is, so far, among COVID-19 medications perhaps the most effective drug for patients with severe symptoms. We observe a parallel redox biology behavior between the antioxidant action of celastrol when scavenging the superoxide radical, and the adduct formation of celastrol with the main COVID-19 protease. The related molecular mechanism is envisioned using molecular mechanics and dynamics calculations. It proposes a covalent bond between the S(Cys145) amino acid thiolate and the celastrol A ring, assisted by proton transfers by His164 and His41 amino acids, and a π interaction from Met49 to the celastrol B ring. Specifically, celastrol possesses two moieties that are able to independently scavenge the superoxide radical: the carboxylic framework located at ring E, and the methide-quinone ring A. The latter captures the superoxide electron, releasing molecular oxygen, and is the feature of interest that correlates with the mechanism of COVID-19 inhibition. This unusual scavenging of the superoxide radical is described using density functional theory (DFT) methods, and is supported experimentally by cyclic voltammetry and X-ray diffraction.     

Beyond “Big Eaters”: The Versatile Role of Alveolar Macrophages in Health and Disease

Macrophages act as immune scavengers and are important cell types in the homeostasis of various tissues. Given the multiple roles of macrophages, these cells can also be found as tissue resident macrophages tightly integrated into a variety of tissues in which they fulfill crucial and organ-specific functions. The lung harbors at least two macrophage populations: interstitial and alveolar macrophages, which occupy different niches and functions. In this review, we provide the latest insights into the multiple roles of alveolar macrophages while unraveling the distinct factors which can influence the ontogeny and function of these cells. Furthermore, we will highlight pulmonary diseases, which are associated with dysfunctional macrophages, concentrating on congenital diseases as well as pulmonary infections and impairment of immunological pathways. Moreover, we will provide an overview about different treatment approaches targeting macrophage dysfunction. Improved knowledge of the role of macrophages in the onset of pulmonary diseases may provide the basis for new pharmacological and/or cell-based immunotherapies and will extend our understanding to other macrophage-related disorders.     

Prenatal THC Does Not Affect Female Mesolimbic Dopaminergic System in Preadolescent Rats

Cannabis use among pregnant women is increasing worldwide along with permissive sociocultural attitudes toward it. Prenatal cannabis exposure (PCE), however, is associated with adverse outcome among offspring, ranging from reduced birth weight to child psychopathology. We have previously shown that male rat offspring prenatally exposed to Δ9-tetrahydrocannabinol (THC), a rat model of PCE, exhibit extensive molecular, cellular, and synaptic changes in dopamine neurons of the ventral tegmental area (VTA), resulting in a susceptible mesolimbic dopamine system associated with a psychotic-like endophenotype. This phenotype only reveals itself upon a single exposure to THC in males but not females. Here, we characterized the impact of PCE on female behaviors and mesolimbic dopamine system function by combining in vivo single-unit extracellular recordings in anesthetized animals and ex vivo patch clamp recordings, along with neurochemical and behavioral analyses. We find that PCE female offspring do not show any spontaneous or THC-induced behavioral disease-relevant phenotypes. The THC-induced increase in dopamine levels in nucleus accumbens was reduced in PCE female offspring, even when VTA dopamine activity in vivo and ex vivo did not differ compared to control. These findings indicate that PCE impacts mesolimbic dopamine function and its related behavioral domains in a sex-dependent manner and warrant further investigations to decipher the mechanisms determining this sex-related protective effect from intrauterine THC exposure.     

Design,Synthesis, and Characterization of Macrocyclic Inhibitors of the Proprotein Convertase Furin

The activation of viral glycoproteins by the host protease furin is an essential step in the replication of numerous pathogenic viruses. Thus, effective inhibitors of furin could serve as broad-spectrum antiviral drugs. A crystal structure of an inhibitory hexapeptide derivative in complex with furin served as template for the rational design of various types of new cyclic inhibitors. Most of the prepared derivatives are relatively potent furin inhibitors with inhibition constants in the low nanomolar or even sub-nanomolar range. For seven derivatives the crystal structures in complex with furin could be determined. In three complexes, electron density was found for the entire inhibitor. In the other cases the structures could be determined only for the P6/P5-P1 segments, which directly interact with furin. The cyclic derivatives together with two non-cyclic reference compounds were tested as inhibitors of the proteolytic activation and replication of respiratory syncytial virus in cells. Significant antiviral activity was found for both linear reference inhibitors, whereas a negligible efficacy was determined for the cyclic derivatives.     

Customizing MRI-Compatible Multifunctional Neural Interfaces through Fiber Drawing

Fiber drawing enables scalable fabrication of multifunctional flexible fibers that integrate electrical, optical, and microfluidic modalities to record and modulate neural activity. Constraints on thermomechanical properties of materials, however, have prevented integrated drawing of metal electrodes with low-loss polymer waveguides for concurrent electrical recording and optical neuromodulation. Here, two fabrication approaches are introduced: 1) an iterative thermal drawing with a soft, low melting temperature (T_m) metal indium, and 2) a metal convergence drawing with traditionally non-drawable high T_m metal tungsten. Both approaches deliver multifunctional flexible neural interfaces with low-impedance metallic electrodes and low-loss waveguides, capable of recording optically-evoked and spontaneous neural activity in mice over several weeks. These fibers are coupled with a light-weight mechanical microdrive (1 g) that enables depth-specific interrogation of neural circuits in mice following chronic implantation. Finally, the compatibility of these fibers with magnetic resonance imaging is demonstrated and they are applied to visualize the delivery of chemical payloads through the integrated channels in real time. Together, these advances expand the domains of application of the fiber-based neural probes in neuroscience and neuroengineering.     

Biocompatible Cubic Boron Nitride: A Noncytotoxic Ultrahard Material

Cubic boron nitride (c-BN) has an ultrahardness and a large bandgap energy like diamond. In the last 30 years, most of the attention has been directed towards the mechanical and electronic applications of c-BN, while its biological potential has been overlooked. The authors report in vitro biocompatibility of high-quality c-BN films prepared by plasma-enhanced chemical vapor deposition using the chemistry of fluorine. c-BN films become superhydrophilic when chemical-treated in hydrogen and nitrogen plasmas with or without the impact of low-energy ions due to a marked increase in polar part of the surface free energy by removal of the fluorine atoms terminating c-BN surfaces. Satisfactory proliferation and differentiation of osteoblastic cells comparable with a control sample and a superhydrophilic nanocrystalline diamond film, and the formation of mineral deposits by biomineralization are confirmed on the superhydrophilic c-BN films with negative values of zeta potential. The results demonstrate a high potential of c-BN as a noncytotoxic ultrahard coating material for biological and biomedical applications.