1,078 research outputs found
Ecological Distribution and Oenological Characterization of Native Saccharomyces cerevisiae in an Organic Winery
The relation between regional yeast biota and the organoleptic characteristics of wines has attracted growing attention among winemakers. In this work, the dynamics of a native Saccharomyces cerevisiae
population was investigated in an organic winery. In this regard, the occurrence and the persistence of
native S. cerevisiae were evaluated in the vineyard and winery and during spontaneous fermentation of
two nonconsecutive vintages. From a total of 98 strains, nine different S. cerevisiae biotypes were identified
that were distributed through the whole winemaking process, and five of them persisted in both vintages.
The results of the oenological characterization of the dominant biotypes (I and II) show a fermentation
behavior comparable to that exhibited by three common commercial starter strains, exhibiting specific
aromatic profiles. Biotype I was characterized by some fruity aroma compounds, such as isoamyl acetate
and ethyl octanoate, while biotype II was differentiated by ethyl hexanoate, nerol, and β-damascenone
production also in relation to the fermentation temperature. These results indicate that the specificity of
these resident strains should be used as starter cultures to obtain wines with distinctive aromatic profiles
Endothelial cells, endoplasmic reticulum stress and oxysterols
Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell viability and are involved in several diseases, including atherosclerosis. Mounting evidence linked the atherosclerosis to endothelium dysfunction; in fact, the endothelium regulates the vascular system with roles in processes such as hemostasis, cell cholesterol, hormone trafficking, signal transduction and inflammation. Several papers shed light the ability of oxysterols to induce apoptosis in different cell lines including endothelial cells. Apoptotic endothelial cell and endothelial denudation may constitute a critical step in the transition to plaque erosion and vessel thrombosis, so preventing the endothelial damaged has garnered considerable attention as a novel means of treating atherosclerosis. Endoplasmic reticulum (ER) is the site where the proteins are synthetized and folded and is necessary for most cellular activity; perturbations of ER homeostasis leads to a condition known as endoplasmic reticulum stress. This condition evokes the unfolded protein response (UPR) an adaptive pathway that aims to restore ER homeostasis. Mounting evidence suggests that chronic activation of UPR leads to cell dysfunction and death and recently has been implicated in pathogenesis of endothelial dysfunction. Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation, maintaining basal levels of autophagic activity it is critical for cell survival. Several evidence suggests that persistent ER stress often results in stimulation of autophagic activities, likely as a compensatory mechanism to relieve ER stress and consequently cell death. In this review, we summarize evidence for the effect of oxysterols on endothelial cells, especially focusing on oxysterols-mediated induction of endoplasmic reticulum stress
Salmeterol, a \u3b22 Adrenergic Agonist, Promotes Adult Hippocampal Neurogenesis in a Region-Specific Manner.
Neurogenesis persists in the subgranular zone of the hippocampal formation in the adult mammalian brain. In this area, neural progenitor cells (NPCs) receive both permissive and instructive signals, including neurotransmitters, that allow them to generate adult-born neurons which can be functionally integrated in the preexisting circuit. Deregulation of adult hippocampal neurogenesis (ahNG) occurs in several neuropsychiatric and neurodegenerative diseases, including major depression, and represents a potential therapeutic target. Of interest, several studies suggested that, both in rodents and in humans, ahNG is increased by chronic administration of classical monoaminergic antidepressant drugs, suggesting that modulation of this process may participate to their therapeutic effects. Since the established observation that noradrenergic innervations from locus coeruleus make contact with NPC in the dentate gyrus, we investigated the role of beta adrenergic receptor (\u3b2-AR) on ahNG both in vitro and in vivo. Here we report that, in vitro, activation of \u3b22-AR by norepinephrine and \u3b22-AR agonists promotes the formation of NPC-derived mature neurons, without affecting NPC survival or differentiation toward glial lineages. Additionally, we show that a selective \u3b22-AR agonist able to cross the blood-brain barrier, salmeterol, positively modulates hippocampal neuroplasticity when chronically administered in adult na\uefve mice. Indeed, salmeterol significantly increased number, maturation, and dendritic complexity of DCX+ neuroblasts. The increased number of DCX+ cells was not accompanied by a parallel increase in the percentage of BrdU+/DCX+ cells suggesting a potential prosurvival effect of the drug on neuroblasts. More importantly, compared to vehicle, salmeterol promoted ahNG, as demonstrated by an increase in the actual number of BrdU+/NeuN+ cells and in the percentage of BrdU+/NeuN+ cells over the total number of newly generated cells. Interestingly, salmeterol proneurogenic effects were restricted to the ventral hippocampus, an area related to emotional behavior and mood regulation. Since salmeterol is commonly used for asthma therapy in the clinical setting, its novel pharmacological property deserves to be further exploited with a particular focus on drug potential to counteract stress-induced deregulation of ahNG and depressive-like behavior
Orbital Hall effect and topology on a two-dimensional triangular lattice: from bulk to edge
We investigate a generalized multi-orbital tight-binding model on a
triangular lattice, a system prevalent in a wide range of two-dimensional
materials, and particularly relevant for simulating transition metal
dichalcogenide monolayers. We show that the interplay between spin-orbit
coupling and different symmetry-breaking mechanisms leads to the emergence of
four distinct topological phases [Eck, P., \textit{et al.}, Phys. Rev. B, 107
(11), 115130 (2023)]. Remarkably, this interplay also triggers the orbital Hall
effect with distinguished characteristics. Furthermore, by employing the
Landauer-B\"uttiker formula, we establish that in the orbital Hall insulating
phase, the orbital angular momentum is carried by edge states present in
nanoribbons with specific terminations. We also show that, as expected, they do
not have topological protection against the disorder of the edge states
belonging to a first-order topological insulator
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