Search results for "Barrier"

Molecular dynamics simulations of heavy ion induced defects in SiC Schottky diodes

2018

Heavy ion irradiation increases the leakage current in reverse-biased SiC Schottky diodes. This letter demonstrates, via molecular dynamics simulations, that a combination of bias and ion-deposited energy is required to produce the degradation. Peer reviewed

Data from: The Pillars of Hercules as a bathymetric barrier to gene-flow promoting isolation in a global deep-sea shark (Centroscymnus coelolepis)

2015

Knowledge of the mechanisms limiting connectivity and gene-flow in deep-sea ecosystems is limited, especially for deep-sea sharks. The Portuguese dogfish (Centroscymnus coelolepis) is a globally distributed and Near Threatened deep-sea shark. C. coelolepis population structure was studied using 11 nuclear microsatellite markers and a 497 bp fragment from the mtDNA Control Region. High levels of genetic homogeneity across the Atlantic (ΦST=-0.0091, FST= 0.0024, P > 0.05) were found suggesting one large population unit at this basin. The low levels of genetic divergence between Atlantic and Australia (ΦST= 0.0744, P<0.01; FST=0.0015, P > 0.05) further suggested that this species may …

Pericytes: a target for in vivo reprogramming?

2013

Non-covalent interactions of N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives—a case of intramolecular N-oxide hydrogen bonds

2017

The crystal structures of new N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives are reported. The results of X-ray diffraction showed the existence of intramolecular hydrogen bonding between carboxamide nitrogen donors and N-oxide oxygen acceptors. The use of Quantum Theory of Atoms in Molecules allowed its classification as a strong interaction, with energy about 10 kcal/mol, and of intermediate character between closed shell and shared bonds. Comparison of experimental data and quantum theoretical calculations indicated that a substituent attached to the phenyl ring in the para position influences the strength and geometry of the title hydrogen bonding. Stronger π-elect…

2020

Background: ABCB1 (P-glycoprotein) and ABCG2 (breast cancer resistance protein) are co-localized at the blood-brain barrier (BBB), where they restrict the brain distribution of many different drugs. Moreover, ABCB1 and possibly ABCG2 play a role in Alzheimer’s disease (AD) by mediating the brain clearance of beta-amyloid (Aβ) across the BBB. This study aimed to compare the abundance and activity of ABCG2 in a commonly used β-amyloidosis mouse model (APP/PS1-21) with age-matched wild-type mice. Methods: The abundance of ABCG2 was assessed by semi-quantitative immunohistochemical analysis of brain slices of APP/PS1-21 and wild-type mice aged 6 months. Moreover, the brain distribution of two d…

Immigrants Psychopathology: Emerging Phenomena and Adaptation of Mental Health Care Setting by Native Language.

2018

Mental health of immigrants is an important social and clinical issue. Immigrants may report higher rates of mental disorders and lower levels of use of mental health service with respect to natives. The aim of the present work is to review recent findings of the psychopathology of immigrants and analyze how to adapt the mental care settings through the use of mother tongues. We searched the literature to individuate and review the most recent scientific articles focused on the psychopathology of immigrants realized in Europe. Moreover, we summarized the guidelines about immigrants mental health care and we focused on the barriers caused by language. We individuated 15 papers reporting data…

Arsenic Through the Gastrointestinal Tract

2015

Intestinal barrier function regulates (micro-)nutrient absorption and host defense mechanisms at the mucosal interface with the external environment. Maintaining gut homeostasis is essential for human health; however, many factors including food and water pollutants may affect the physiological balance at the intestinal level. One of the contaminants of highest health concern is arsenic, which affects more than 200 million people worldwide, causing cancer and cardiovascular and metabolic diseases. Arsenic affects intestinal health by disrupting barrier function and inducing inflammatory responses. Processes involved in the transiting of arsenic through the gastrointestinal tract can affect …

Influence of polyunsaturated fatty acids on Cortisol transport through MDCK and MDCK-MDR1 cells as blood-brain barrier in vitro model.

2011

Abstract Transport across the blood–brain barrier is a relevant factor in the pharmacological action of many drugs and endogenous substances whose action site is located in brain. An overactive P-gp has been suggested to be of relevance for the resistance of the HPA system to be suppressed by glucocorticoids, which is one of the best described biological abnormalities in certain types of depression. PUFA acids have shown clinical efficacy in depressed patients and the hypothesis is that these compounds are able to reduce HPA axis activity as this effect has been shown in animal models of depression. The objective of the present work was (1) to characterize Cortisol transport through MDCK an…

CRP-induced levels of oxidative stress are higher in brain than aortic endothelial cells

2010

C-reactive protein (CRP) has been demonstrated to induce blood-brain barrier disruption (BBB) involving NAD(P)H-oxidase dependent oxidative stress. It is unclear why CRP affects the BBB and not other vascular beds following stroke. Therefore we examined CRP receptor and NAD(P)H-oxidase expression levels in bovine brain- (BEC) and aortic endothelial cells. Dichlorodihydrofluorescein measurements revealed significantly higher CRP-induced reactive oxygen species (ROS) levels in BEC. Protein expression of the CRP-receptors CD16, CD32 and of the NAD(P)H-oxidase subunit p22phox were also significantly higher in BEC. In conclusion BEC show a higher vulnerability to CRP due to increased levels of C…

Mechanisms of C-reactive protein-induced blood-brain barrier disruption.

2009

Background and Purpose— Increased mortality after stroke is associated with brain edema formation and high plasma levels of the acute phase reactant C-reactive protein (CRP). The aim of this study was to examine whether CRP directly affects blood–brain barrier stability and to analyze the underlying signaling pathways. Methods— We used a cell coculture model of the blood–brain barrier and the guinea pig isolated whole brain preparation. Results— We could show that CRP at clinically relevant concentrations (10 to 20 μg/mL) causes a disruption of the blood–brain barrier in both approaches. The results of our study further demonstrate CRP-induced activation of surface Fcγ receptors CD16/32 fo…