2,628 research outputs found
Excitability in a nonlinear magnetoacoustic resonator
We report a nonlinear acoustic system displaying excitability. The considered
system is a magnetostrictive material where acoustic waves are parametrically
generated. For a set of parameters, the system presents homoclinic and
heteroclinic dynamics, whose boundaries define a excitability domain. The
excitable behaviour is characterized by analyzing the response of the system to
different external stimuli. Single spiking and bursting regimes have been
identified.Comment: 4 pages, 5 figure
Application of a novel statistical model for quantitative proteomics by labeling to the study of VEGF-induced angiogenesis in vascular endothelial cells
Comunicaciones a congreso
Hábitos de sueño y problemas relacionados con el sueño en adolescentes: relación con el rendimiento escolar
ObjetivoConocer la prevalencia de trastornos de sueño en los adolescentes. Describir los hábitos de sueño de los adolescentes y su relación con los trastornos del sueño y los factores asociados. Conocer la relación entre los trastornos del sueño y/o los hábitos de sueño inadecuados con el rendimiento escolar.DiseñoEstudio observacional, descriptivo y transversal.EmplazamientoInstitutos de enseñanza secundaria obligatoria (ESO) de la ciudad de Cuenca.ParticipantesUn total de 1.293 alumnos escolarizados en primero y cuarto cursos de ESO.Mediciones principalesHábitos de sueño en dÃas lectivos y fines de semana y prevalencia de trastornos del sueño medidos mediante un cuestionario estructurado con preguntas abiertas y cerradas, autoadministrado y anónimo. Se determinó el rendimiento escolar de los alumnos y su relación con los hábitos y trastornos de sueño.ResultadosDe los 1.293 alumnos matriculados, completaron la encuesta 1.155 (89,33%), 537 (45,9%) chicos y 618 (54,1%) chicas, con una media de edad de 14 años (rango, 11-18 años). Los dÃas laborables se acuestan en promedio a las 23.17 y se levantan a las 7.46 (tiempo medio, 8 h y 18 min) y los fines de semana se acuestan a la 1.02 y se levantan a las 10.42 (tiempo medio, 9 h y 40 min). El 45,4% declara dormir mal la noche del domingo al lunes. El promedio de asignaturas suspendidas es mayor en los adolescentes con queja de sueño (2,28 frente a 1,91; p = 0,04), los que se levantan cansados (2,17 frente a 1,97; p = 0,048) y los que tienen somnolencia diurnal (2,17 frente a 1,75; p = 0,004).ConclusionesEl horario escolar conlleva deuda de sueño durante la semana que se recupera parcialmente el fin de semana. En los fines de semana se produce una rotura en los hábitos de sueño de los adolescentes. Los adolescentes con problemas relacionados con el sueño muestran peor rendimiento escolar.ObjectiveTo determine the prevalence of sleep disorders in adolescence.To describe sleeping habits of adolescents in relation to sleep disorders and associated factors. To determine the relation between sleep disorders/inappropiate sleeping habits and school performance.DesignObservational, descriptive, crosssectional study.SettingSecondary school of Cuenca (city in Spain).Participants1293 school children of first and fourth curses of secondary education.Main measuresStructured questionnaire with opened and closed questions on sleeping habits during weekdays and at weekends and sleep disorders to be answered by the adolescents anonymously and on their own. Student's school performance with relation with to sleeping habits and sleep disorders were determined.Results1155 students out of 1293 (response rate 89.33%) answered the questionnaire, 537 (45.9%) boys and 618 (54.1%) girls, 14 years old on average (between 11-18 years). On weekdays students went to bed at 23.17 h and got up at 7.46 h (average sleeping time =8 hours and 18 minutes). At weekends they went to bed at 1.02 h and got up at 10.42 h (average sleeping time =9 hours and 40 minutes). 45.4% of students said to sleep badly on Sunday night's.On average the number of subjects failed in class is higher with adolescents who complain about sleep (2.28 vs 1.91; P=.04), who are tired at waking up time (2.17 vs 1.97; P=.048) and who have morning sleepiness (2.17 vs 1.75; P=.004).ConclusionsSchools hours cause deficitsleeping time during weekdays which is partly made up for at weekend. At weekends there is an interruption of the adolescent's sleeping habits. School performance of adolescents with sleep disorders is lower
The Intrinsic Fundamental Group of a Linear Category
We provide an intrinsic definition of the fundamental group of a linear
category over a ring as the automorphism group of the fibre functor on Galois
coverings. If the universal covering exists, we prove that this group is
isomorphic to the Galois group of the universal covering. The grading deduced
from a Galois covering enables us to describe the canonical monomorphism from
its automorphism group to the first Hochschild-Mitchell cohomology vector
space.Comment: Final version, to appear in Algebras and Representation Theor
The first Hochschild cohomology group of a schurian cluster-tilted algebra
Given a cluster-tilted algebra B we study its first Hochschild cohomology group HH1(B) with coefficients in the B-B-bimodule B. We find several consequences when B is representation-finite, and also in the case where B is cluster-tilted of type Ã.Fil: Assem, Ibrahim. University of Sherbrooke; CanadáFil: Redondo, Maria Julia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Instituto de Matemática BahÃa Blanca. Universidad Nacional del Sur. Departamento de Matemática. Instituto de Matemática BahÃa Blanca; Argentin
Deficiencia de vitamina D en niños aragoneses sanos
Introducción: la principal acción de la vitamina D es mantener la concentración de calcio y fósforo dentro del rango fisiológico permitiendo el metabolismo normal y la mineralización ósea. Últimamente, se han descrito receptores de vitamina D en muchos tejidos y se ha relacionado la deficiencia de la vitamina D no solo con raquitismo y osteomalacia, sino también con mayor riesgo de diabetes, obesidad, enfermedades cardiovasculares, oncológicas, infecciosas y autoinmunes.
Objetivo: el objetivo del estudio fue conocer la concentración de vitamina D en una población pediátrica sana y comprobar sus factores influyentes, asà como analizar la situación actual de profilaxis de vitamina D y valorar la eficacia de las recomendaciones actuales.
Métodos: se seleccionaron 107 pacientes sanos, de edades comprendidas entre uno y 15 años, que precisaron una analÃtica sanguÃnea como preoperatorio de cirugÃa menor, cuya patologÃa no influyera en los parámetros del estudio.
Resultados: la muestra estaba constituida en un 78, 5% por varones y presentaba una media de edad de 7, 17 ± 3, 79 años. La concentración media de vitamina D fue de 26, 07 ± 7, 11 ng/ml y hasta un 72, 9% presentaba niveles insuficientes. Se dividió la muestra en dos grupos: pacientes con hipovitaminosis D y pacientes con niveles óptimos de vitamina D. Se observó en el grupo con hipovitaminosis un predominio de varones, mayor Ãndice de masa corporal y la presencia de fototipos extremos asà como provenientes de padres inmigrantes. También presentaban mayor riesgo de hipovitaminosis los que no habÃan realizado profilaxis durante el primer año de vida. Conclusiones: se pone de manifiesto el alto porcentaje de población infantil sana con déficit de vitamina D y que las recomendaciones actuales de profilaxis no son llevadas a cabo por la población como recomiendan las guÃas actuales
Background: the main action of vitamin D is to maintain the concentration of calcium and phosphorus within the physiological range, allowing normal metabolism and bone mineralization. Vitamin D receptors have recently been described in many tissues, therefore vitamin D deficiency has been related not only to rickets, but also to increased risk of diabetes, obesity, cardiovascular, oncological, infectious and autoimmune diseases. Objective: the aim of the study was to know the vitamin D concentration in a healthy pediatric population and to verify its influential factors, as well as to analyze the current situation of vitamin D prophylaxis and to evaluate the effectiveness of current recommendations. Methods: one hundred and seven healthy patients aged between one and 15 years were selected, who required a blood test as a preoperative minor surgery and whose pathology did not influence the parameters of the study. Results: the sample analyzed had a total of 78.5% males and a mean age of 7.17 ± 3.79 years. Mean values of vitamin D were 26.07 ± 7.11 ng/ml; up to 72.9% had insufficient levels. The sample was divided into two groups: patients with hypovitaminosis D and patients with optimal vitamin D levels. A predominance of males with a higher body mass index, from immigrant parents, and the presence of extreme phototypes were observed in the hypovitaminosis group. There was also a higher risk of hypovitaminosis in those who had not performed prophylaxis during the first year of life. Conclusions: the high percentage of healthy children with vitamin D deficiency is evident, and current recommendations for prophylaxis are not carried out by the population as recommended by current guidelines
A Novel Human Ghrelin Variant (In1-Ghrelin) and Ghrelin-O-Acyltransferase Are Overexpressed in Breast Cancer: Potential Pathophysiological Relevance
The human ghrelin gene, which encodes the ghrelin and obestatin peptides, contains 5 exons (Ex), with Ex1-Ex4 encoding a
117 amino-acid (aa) preproprotein that is known to be processed to yield a 28-aa (ghrelin) and/or a 23-aa (obestatin) mature
peptides, which possess biological activities in multiple tissues. However, the ghrelin gene also encodes additional peptides
through alternative splicing or post-translational modifications. Indeed, we previously identified a spliced mRNA ghrelin
variant in mouse (In2-ghrelin-variant), which is regulated in a tissue-dependent manner by metabolic status and may thus
be of biological relevance. Here, we have characterized a new human ghrelin variant that contains Ex0-1, intron (In) 1, and
Ex2 and lacks Ex3-4. This human In1-ghrelin variant would encode a new prepropeptide that conserves the first 12aa of
native-ghrelin (including the Ser3-potential octanoylation site) but has a different C-terminal tail. Expression of In1-variant
was detected in 22 human tissues and its levels were positively correlated with those of ghrelin-O-acyltransferase (GOAT;
p = 0.0001) but not with native-ghrelin expression, suggesting that In1-ghrelin could be a primary substrate for GOAT in
human tissues. Interestingly, levels of In1-ghrelin variant expression in breast cancer samples were 8-times higher than
those of normal mammary tissue, and showed a strong correlation in breast tumors with GOAT (p = 0.0001), ghrelin
receptor-type 1b (GHSR1b; p = 0.049) and cyclin-D3 (a cell-cycle inducer/proliferation marker; p = 0.009), but not with nativeghrelin
or GHSR1a expression. Interestingly, In1-ghrelin variant overexpression increased basal proliferation of MDA-MB-231
breast cancer cells. Taken together, our results provide evidence that In1-ghrelin is a novel element of the ghrelin family
with a potential pathophysiological role in breast cance
Incidents control in radiotherapy oncology
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conservat i ubicat a la porta de la UB. Mesura
1,60 x 2,20 metre si és de pedra sorrenca
Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension
This is the peer-reviewed version of the following article: "Toll-like receptor 4 contributes to vascular remodelling and endothelial
dysfunction in angiotensin II-induced hypertension", British Journal of Pharmacology 172.12 (2015): 3159-76 which has been published in final form at http://dx.doi.org/10.1111/bph.13117 This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingBackground and Purpose
Toll-like receptor 4 (TLR4) signalling contributes to inflammatory cardiovascular diseases, but its role in hypertension and the associated vascular damage is not known. We investigated whether TLR4 activation contributed to angiotensin II (AngII)-induced hypertension and the associated vascular structural, mechanical and functional alterations.
Experimental Approach
AngII was infused (1.44 mg·kg−1·day−1, s.c.) for 2 weeks in C57BL6 mice, treated with a neutralizing anti-TLR4 antibody or IgG (1 μg·day−1); systolic BP (SBP) and aortic cytokine levels were measured. Structural, mechanical and contractile properties of aortic and mesenteric arterial segments were measured with myography and histology. RT-PCR and Western blotting were used to analyse these tissues and cultured vascular smooth muscle cells (VSMC) from hypertensive rats (SHR).
Key Results
Aortic TLR4 mRNA levels were raised by AngII infusion. Anti-TLR4 antibody treatment of AngII-treated mice normalised: (i) increased SBP and TNF-α, IL-6 and CCL2 levels; (ii) vascular structural and mechanical changes; (iii) altered aortic phenylephrine- and ACh-induced responses; (iv) increased NOX-1 mRNA levels, superoxide anion production and NAD(P)H oxidase activity and effects of catalase, apocynin, ML-171 and Mito-TEMPO on vascular responses; and (v) reduced NO release and effects of L-NAME on phenylephrine-induced contraction. In VSMC, the MyD88 inhibitor ST-2825 reduced AngII-induced NAD(P)H oxidase activity. The TLR4 inhibitor CLI-095 reduced AngII-induced increased phospho-JNK1/2 and p65 NF-κB subunit nuclear protein expression.
Conclusions and Implications
TLR4 up-regulation by AngII contributed to the inflammation, endothelial dysfunction, vascular remodelling and stiffness associated with hypertension by mechanisms involving oxidative stress. MyD88-dependent activation and JNK/NF-κB signalling pathways participated in these alterationsThis work was supported by Ministerio de EconomÃa y Competitividad
(SAF2012-36400), Instituto de Salud Carlos III (Red de Investigación Cardiovascular
RD12/0042/0024 and RD12/0042/0033) and URJC (PRIN13_CS12). AMB was
supported by the Ramón y Cajal Program (RYC-2010-06473)
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