Search results for "Experimental model"

Modelling of laser beam texturing process: experimental and numerical approaches

2007

The aim of this work is to reache a better control of the laser beam surface texturing process on three materials: 304L, TA6V and AA6056 alloys. For this purpose, two complementary methods, experimental and numerical modelling, have been used. As a result of the experimental design approach, it was observed that the laser surface texturing process of 304L and TA6V alloys is strongly influenced by the pulse energy and frequency. In order to obtain a surface roughness Sa < 5 µm for the highest possible productivity it is necessary to work with an energy of 5 mJ and a frequency ranging between 10 and 12 kHz. Unfortunately, for aluminium alloy AA6056, it is necessary to make a choice between ha…

Sp1 transcription factor interaction with accumulated prelamin a impairs adipose lineage differentiation in human mesenchymal stem cells: essential r…

2012

Abstract Lamin A (LMNA)-linked lipodystrophies may be either genetic (associated with LMNA mutations) or acquired (associated with the use of human immunodeficiency virus protease inhibitors [PIs]), and in both cases they share clinical features such as anomalous distribution of body fat or generalized loss of adipose tissue, metabolic alterations, and early cardiovascular complications. Both LMNA-linked lipodystrophies are characterized by the accumulation of the lamin A precursor prelamin A. The pathological mechanism by which prelamin A accumulation induces the lipodystrophy associated phenotypes remains unclear. Since the affected tissues in these disorders are of mesenchymal origin, we…

Efecto del estiramiento miocárdico sobre las frecuencias de activación determinadas mediante análisis espectral durante la fibrilación ventricular

2002

Introduction and objectives. The aim of this study was to analyze the effects of myocardial stretching on excitation frequencies, as determined by spectral analysis, during ventricular fibrillation. Methods. In 12 isolated rabbit heart preparations, ventricular activation during ventricular fibrillation was recorded with multiple electrodes. Recordings were obtained before, during and after ventricular dilatation produced with an intraventricular balloon. The dominant frequency of the signals obtained with each of the electrodes was determined by spectral analysis. Results. During the control phase, the mean, minimum and maximum dominant frequencies were, respectively, 14.3 ± 1.7, 12.5 ± 1.…

Prosthetic strap system for simplified ventral hernia repair. Its results in a porcine experimental model.

2010

Abstract: Introduction Aiming to achieve a simplified ventral hernia repair, a proprietary shaped mesh was experimentally tested in the porcine model. The mesh is structured with a large central body and radiating straps. The friction of the straps passing through the tissues are hypothesized to be adequate to maintain the mesh in place during tissue ingrowth, avoiding classic point fixation while ensuring a wide coverage of the abdomen. Methods The mesh, having 6 radial straps, was placed using a sublay preperitoneal technique in 4 pigs. All straps were passed laterally through the abdominal wall and exteriorized from the skin. The straps were trimmed at the level of the skin, allowing the…

P315Study of the induction and characteristics of ventricular fibrillation in an experimental model of metabolic syndrome

2018

P330Modifications of short-term heart rate varibility and intrinsic pacemaker variability in an experimental model of metabolic syndrome

2018

A regenerative 3D scaffold for inguinal hernia repair. MR imaging and histological cross evidence. Qualitative study

2021

Abstract Background Inguinal hernia is a degenerative disease occurring in a high motile surround. Stopping degeneration and promoting tissue regeneration should be the treatment goal. Groin hernias are conventionally managed with static flat meshes, mostly fixated to the delicate inguinal environment. Far from a regenerative effect, the biologic response of conventional hernia meshes is characterized by a foreign body reaction leading to a stiff/shrunken scar plate, which is often the source of unpleasant complications. Recently, a newly engineered 3D device for inguinal hernia repair – ProFlor-has been developed to produce a regenerative biological response. Unlike conventional hernia mes…

Time and frequency domain analysis of long-term heart rate variability in an experimental model of diet-induced metabolic syndrome

2021

Abstract Background Metabolic syndrome (MetS) is defined as the set of at least three of the following conditions: central obesity, elevation of triglycerides, decreased in high-density lipoproteins, systemic hypertension and glucose intolerance. MetS is linked with a high prevalence of cardiovascular disease, including sudden cardiac death and atrial arrhythmias, which may be a consequence of changes related to the structure, function and autonomic control of the heart. One of the underlying mechanisms responsible could be the alteration of sinus node automaticity. Heart rate variability (HRV) analysis is a useful non-invasive tool for evaluating alterations in neural control of cardiac au…

Effect of ischemic postconditioning on microvascular obstruction in reperfused myocardial infarction. Results of a randomized study in patients and o…

2014

Background: Ischemic postconditioning (PCON) appears as a potentially beneficial tool in ST-segment elevation myocardial infarction (STEMI). We evaluated the effect of PCON on microvascular obstruction (MVO) in STEMI patients and in an experimental swine model. Methods: A prospective randomized study in patients and an experimental study in swine were carried out in two university hospitals in Spain. 101 consecutive STEMI patients were randomized to undergo primary angio-plasty followed by PCON or primary angioplasty alone (non-PCON). Using late gadolinium enhancement cardiovascular magnetic resonance, infarct size and MVO were quantified (% of left ventricular mass). In swine, using an ang…

Comparison of adjuvant and adjuvant-free murine experimental asthma models

2009

Introduction The most widely used protocol for the induction of experimental allergic airway inflammation in mice involves sensitization by intraperitoneal (i.p.) injections of the antigen ovalbumin (OVA) used in conjunction with the adjuvant aluminium hydroxide (alum). Although adjuvants are frequently used, there are questions regarding the necessity of alum for murine asthma studies due to the non-physiological nature of this chemical. Objective The objective of this study was to compare experimental asthma phenotypes between adjuvant and adjuvant-free protocols of murine allergic airway inflammation in an attempt to develop a standardized alternative to adjuvant use. Method An adjuvant-…