Search results for "Zone"

Observation of elastic anisotropy in strained optical nanofibers using Brillouin spectroscopy

2019

Optical nanofibers (ONFs) are excellent nanophotonic platforms for many applications such as optical sensing, quantum photonics, and nonlinear optics, due to both tight optical confinement and their evanescent field. From an acoustic viewpoint, it has recently been reported the observation of a new class of Brillouin acoustic resonances in optical nanofibers, including hybrid shear/longitudinal acoustic waves (HAWs) and surface acoustic waves (SAWs) [1–2]. It has been later shown that, under axial tensile strain, the Brillouin frequency shifts (BFS) of these elastic resonances are fundamentally different from that of standard optical fibers [3]. This is principally due to the hybrid nature …

2016

In the perinatal as well as the adult CNS, the subventricular zone (SVZ) of the forebrain is the largest and most active source of neural stem cells (NSCs) that generates neurons and oligodendrocytes (OLs), the myelin forming cells of the CNS. Recent advances in the field are beginning to shed light regarding SVZ heterogeneity, with the existence of spatially segregated microdomains that are intrinsically biased to generate phenotypically distinct neuronal populations. Although most research has focused on this regionalization in the context of neurogenesis, newer findings underline that this also applies for the genesis of OLs under the control of specific patterning molecules. In this min…

Hypocellularity in the murine model for Down Syndrome Ts65Dn is not affected by adult neurogenesis

2016

Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity …

Crystal structure of (3E)-5-nitro-3-(2-phenylhydrazinylidene)-1H-indol-2(3H)-one

2017

The reaction between 5-nitroisatin and phenylhydrazine in acidic ethanol yields the title compound, C14H10N4O3, whose molecular structure deviates slightly from a planar geometry (r.m.s. deviation = 0.065 Å for the mean plane through all non-H atoms). An intramolecular N—H...O hydrogen bond is present, forming a ring of graph-set motifS(6). In the crystal, molecules are linked by N—H...O and C—H...O hydrogen-bonding interactions into a two-dimensional network along (120), and rings of graph-set motifR22(8),R22(26) andR44(32) are observed. Additionally, a Hirshfeld surface analysis suggests that the molecules are stacked along [100] through C=O...Cginteractions and indicates that the most im…

Dlk1 dosage regulates hippocampal neurogenesis and cognition

2021

Significance Generation of new neurons occurs normally in the adult brain in two locations: the subventricular zone (SVZ) in the walls of the lateral ventricles and the subgranular zone (SGZ) in the dentate gyrus (DG) of the hippocampus. Neurogenesis in the adult hippocampus has been implicated in cognitive functions such as learning, memory, and recovery of stress response. Imprinted genes are highly prevalent in the brain and have adult and developmental important functions. Genetic deletion of the imprinted gene Dlk1 from either parental allele shows that DLK1 is a key mediator of quiescence in adult hippocampal NSCs. Additionally, Dlk1 is exquisitely dosage sensitive in the brain with p…

AB0492 INTESTINAL MICROBIOTA COMPOSITION OF PATIENT’S WITH BEHCET’S DISEASE: DIFFERENCES BETWEEN EYE, MUCOCUTANEOUS AND VASCULAR INVOLVEMENT (RHEUMA-…

2020

Background:Recently, it has been shown that changes in microbiota composition play a role in the etiology and pathogenesis of chronic diseases. Changes in oral and intestinal microbiota diversity and composition are suggested in Behcet disease (BD), however there are no study available about the potential gut microbiota changes among different clinical forms of BD.Objectives:The aim of this study was to evaluate the intestinal microbiota composition of patient with BD and healthy controls, and also compare BD patients regarding to their eye, mucocutaneous and vascular involvement.Methods:In this prospective cohort study,27 patients diagnosed with BD and 10 aged and sex matched healthy contr…

Two known therapies could be useful as adjuvant therapy in critical patients infected by COVID-19☆

2020

Pneumonia caused by coronavirus, which originated in Wuhan, China, in late 2019, has been spread around the world already becoming a pandemic. Unfortunately, there is not yet a specific vaccine or effective antiviral drug for treating COVID-19. Many of these patients deteriorate rapidly and require intubation and are mechanically ventilated, which is causing the collapse of the health system in many countries due to lack of ventilators and intensive care beds. In this document we review two simple adjuvant therapies to administer, without side effects, and low cost that could be useful for the treatment of acute severe coronavirus infection associated with acute respiratory syndrome (SARS-C…

Transcriptional Upregulation of DNA Damage Response Genes in Bank Voles (Myodes glareolus) Inhabiting the Chernobyl Exclusion Zone

2018

Exposure to ionizing radiation (IR) from radionuclides released into the environment can damage DNA. An expected response to exposure to environmental radionuclides, therefore, is initiation of DNA damage response (DDR) pathways. Increased DNA damage is a characteristic of many organisms exposed to radionuclides but expression of DDR genes of wildlife inhabiting an area contaminated by radionuclides is poorly understood. We quantified expression of five central DDR genes Atm, Mre11, p53, Brca1, and p21 in the livers of the bank vole Myodes glareolus that inhabited areas within the Chernobyl Exclusion Zone (CEZ) that differed in levels of ambient radioactivity, and also from control areas ou…

A Specialized Vascular Niche for Adult Neural Stem Cells

2008

SummaryStem cells reside in specialized niches that regulate their self-renewal and differentiation. The vasculature is emerging as an important component of stem cell niches. Here, we show that the adult subventricular zone (SVZ) neural stem cell niche contains an extensive planar vascular plexus that has specialized properties. Dividing stem cells and their transit-amplifying progeny are tightly apposed to SVZ blood vessels both during homeostasis and regeneration. They frequently contact the vasculature at sites that lack astrocyte endfeet and pericyte coverage, a modification of the blood-brain barrier unique to the SVZ. Moreover, regeneration often occurs at these sites. Finally, we fi…

Contribution of Excited Ozone and Oxygen Molecules to the Formation of the Stratospheric Ozone Layer

2019

The absorption of UV, visible and near IR radiation by O3 produces transient, electronically excited O3. The absorption of thermal IR radiation ( = 9.065, 9.596 and 14.267 µm) produces vibrationally excited O3 molecules. Thermal absorption is likely the main factor in the self-decay of O3. Photoexcitation of ground state by IR and red light radiation produces singlet oxygens and . Chemical reactions in the stratosphere produce them as well. When reacting with ozone, singlet oxygen produces O (3P) and . By doing so, they tend to maintain the prevailing ozone concentration and are thereby important for the stability of the ozone layer. During the daytime, O(1D), and reach their maximum concen…