Search results for "cerebral"

A Novel Bio-Inspired Approach for High-Performance Management in Service-Oriented Networks

2021

Service-continuity in distributed computing can be enhanced by designing self-organized systems, with a non-fixed structure, able to modify their structure and organization, as well as adaptively react to internal and external environment changes. In this paper, an architecture exploiting a bio-inspired management approach, i.e., the functioning of cell metabolism, for specialized computing environments in Service-Oriented Networks (SONs) is proposed. Similar to the processes acting in metabolic networks, the nodes communicate to each other by means of stimulation or suppression chains giving rise to emergent behaviors to defend against foreign invaders, attacks, and malfunctioning. The mai…

SPH modeling of blood flow in cerebral aneurysms

Gli aneurismi cerebrali sono dilatazioni patologiche di arterie cerebrali. Queste patologie hanno un intrinseco rischio di rottura con conseguenti emorragie intracraniche. Sebbene i meccanismi di formazione, crescita e rottura degli aneurismi cerebrali non sono ancora del tutto compresi, è comunemente riconosciuto che in questi processi i fattori emodinamici giocano un ruolo molto importante. Le simulazioni numeriche possono fornire utili informazioni sull'emodinamica e possono essere usate per applicazioni cliniche. Nei tradizionali metodi numerici basati su una griglia di calcolo il processo di discretizzazione dei vasi cerebrali sui quali insiste un aneurisma è molto complesso. D’altra p…

El encuadre de los temas de salud: cobertura en prensa escrita del daño cerebral adquirido

2014

En este trabajo analizamos el encuadre informativo del Daño cerebral adquirido (DCA) en noticias publicadas en El País, El Mundo y La Vanguardia entre 2010 y 2013. Partiendo de una búsqueda léxica, se seleccionaron los textos que tematizaban el DCA, bien como tema central o secundario, y se analizaron las distintas categorías de encuadre discursivo. Los resultados muestran la escasa presencia del DCA en la prensa generalista, frente a su incidencia en nuestra sociedad, y que esta presencia escasa se refiere sobre todo a aspectos secundarios (prevención, necesidades asistenciales, calidad de vida), con especial magnificación de los avances tecnológicos. This paper analyzes the framing of Acq…

Mechanisms of Cell-Volume Regulation in the Central Nervous System

2017

Function and viability of every cell is dependent on the proper control of its shape and volume. In the brain, which is protected by a rigid outer shell, cell-volume regulation is of particular importance, since large volume changes affect cerebral perfusion and, hence, function. Neuronal activation leads to constant changes of the ionic and metabolic composition of the brain’s extracellular space. These changes are buffered by astrocytes on the expense of constant changes in cell volume. Under pathological conditions, the ability of astrocytes to maintain the homeostasis of the brain is overwhelmed and permanent cell swelling, cytotoxic edema, occurs. The current chapter describes the prin…

Author response: Electrical activity controls area-specific expression of neuronal apoptosis in the mouse developing cerebral cortex

2017

Postnatal neurogenesis and regeneration in the lizard cerebral cortex

1993

Beziehung zwischen Kopfumfang und sonographischer Morphometrie der Ventrikelstrukturen im Neugeborenen- und Säuglingsalter

2001

AIM: To determine normal values of sonographic measurements of the brain in neonates and infants. METHOD: Cerebral ultrasonographic examinations were performed in 143 healthy newborns and infants. The size of the ventricles was determined by ascertaining distances as well as performing planimetric measurements of the ventricular area and circumference in standardized planes. RESULTS: Throughout the course of the study we observed a continous increase in size and a strong correlation with head circumference. The middle coronary plane used for the measurements allows the accurate representation of the ventricles and a more objective assessment of size. CONCLUSION: Based on the morphometric da…

Comparison of the contractile effects of endothelin-1 and sarafotoxin S6b in goat isolated cerebral arteries

1992

1. The effects of endothelium-derived endothelin-1 and snake venom-derived sarafotoxin S6b, peptides with striking structural and functional similarities, were examined and compared in isolated middle cerebral arteries of goats. 2. Endothelin-1 and sarafotoxin S6b contracted cerebral arteries in a concentration-dependent manner. The potency of endothelin-1 (EC50 = 4.9 (3.9-6.2) x 10(-10) M) was about ten times higher than that of sarafotoxin S6b (EC50 = 5.5 (4.4-6.9) x 10(-9) M). The tension returned to basal values after repeated washings and contraction with endothelin-1 could be reproduced. Endothelin-1 and sarafotoxin S6b induced further contraction in arteries precontracted with prosta…

Impairment of the modulatory role of nitric oxide on the endothelin-1-elicited contraction of cerebral arteries: a pathogenetic factor in cerebral va…

1997

OBJECTIVE: Nitric oxide (NO) and endothelin-1 (ET-1) are two endothelium-derived factors probably involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Our aim was twofold, i.e., to ascertain whether endothelial and nonendothelial NO modulates the contractile response of cerebral arteries to ET-1 and to analyze whether this relationship might be impaired after experimental SAH. METHODS: Rings of middle cerebral artery from goats in the control group and from goats with SAH were set up for isometric tension recordings. SAH was induced 3 days before the experiments by infusion of 10 ml of autologous arterial blood through a catheter previously inserted into t…

Role of Hemodynamic Forces in Unruptured Intracranial Aneurysms: An Overview of a Complex Scenario.

2017

Background An understanding of the natural history of unruptured intracranial aneurysms (IAs) has always played a critical role in presurgical or endovascular planning, to avoid possibly fatal events. Size, shape, morphology, and location are known risk factors for rupture of an aneurysm, but morphologic parameters alone may not be sufficient to perform proper rupture risk stratification. Methods We performed a systematic PubMed search and focused on hemodynamics forces that may influence aneurysmal initiation, growth, and rupture. Results We included 223 studies describing several hemodynamic parameters related to aneurysm natural history. In these studies, different modalities of aneurysm…