Search results for "mecA"

La impostura de las cuentas nacionales

2004

La matriz extracelular: morfología, función y biotensegridad (parte I)

2009

La matriz extracelular (MEC) representa una red tridimensional que engloba todos los órganos, tejidos y células del organismo. Constituye un filtro biofísico de protección, nutrición e inervación celular y el terreno para la respuesta inmune, angiogénesis, fibrosis y regeneración tisular. Y representa el medio de transmisión de fuerzas mecánicas a la membrana basal, que a través de las integrinas soporta el sistema de tensegridad y activa los mecanismos epigenéticos celulares. La alteración de la MEC supone la pérdida de su función de filtro eficaz, nutrición, eliminación, denervación celular, pérdida de la capacidad de regeneración y cicatrización y alteración de la transmisión mecánica o …

MECASERMIN TREATMENT OF A CHILD WITH CONGENITAL HYPERINSULINISM LINKED TO INS-R MUTATION

2017

Objectives: Mecasermin is recombinant human insulin-like growth factor 1 (IGF1) which is approved for the treatment of short stature in children with documented primary IGF1 deficiency. Leprechaunism, also known as Donohue syndrome, is a severe disease, secondary to a severe congenital insulin resistance, with prenatal and neonatal growth retardation, typical dysmorphic features, glycaemic dysregulation characterized by hyperinsulinemia and hyperandrogenism. These patients have a poor prognosis with death in the first year of life. Methods: We describe the case of a 3.5 years child, born at 35,4 weeks, with severe fetal growth restriction (weight 1149 gr; length: 38 cm; cranial circumferenc…

High frequencies of antibiotic resistance genes in infants' meconium and early fecal samples

2016

The gastrointestinal tract (GIT) microbiota has been identified as an important reservoir of antibiotic resistance genes (ARGs) that can be horizontally transferred to pathogenic species. Maternal GIT microbes can be transmitted to the offspring, and recent work indicates that such transfer starts before birth. We have used culture-independent genetic screenings to explore whether ARGs are already present in the meconium accumulated in the GIT during fetal life and in feces of 1-week-old infants. We have analyzed resistance to β-lactam antibiotics (BLr) and tetracycline (Tcr), screening for a variety of genes conferring each. To evaluate whether ARGs could have been inherited by maternal tr…

Numerical simulation of heat transfer, fluid flow and elements diffusion during laser welding of dissimilar steels

2017

The design of new steel grades offering equivalent mechanical performances for lower thicknesses and the added value with the possibility to join two different steel grades, require development and control of joining processes. Thanks to high precision and good flexibility, the laser welding became one of the most used processes for joining of dissimilar welded blanks. The prediction of local chemical composition in the weld formed between dissimilar steels in function of the welding parameters is essential because the dilution rate and the distribution of alloying elements in the melted zone determine the final tensile strength of the weld. The goal of the present study is to create and to…

Geometric quality and appearance of surfaces : local and global approaches

2012

Accounting for customers' perception of manufactured goods has become a major challenge for the industry. This process is to be established from early design to retail. Customers are nowadays more aware and detail oriented about perceived quality of products. This allows one to set not only an estimated price but also the expected quality of the product. Surface appearance analysis has therefore become a key industrial issue. Two approaches are proposed here to formalize the detection methodology and provide objective criteria for experts to evaluate surface anomalies. The first proposed approach is based on surface metrology. It consists in analyzing the measured topologies in order to bin…

A comparison between models for the study of static and dynamic behavior of heterogeneous multilayer composite plates

2013

In composite plate structures, it is common to combine different materials with very different Young's moduli and densities. Damping treatments can also be added to prevent high levels of vibration. For discretized problems, the static and dynamic behavior of such heterogeneous structures can be carried out with the 3D elasticity theory but this often leads to very large systems. Therefore, plate theories and particularly equivalent single layer models are often preferred. Classical plate theories have then been adapted to these particular structures using shear correction factors. Higher order shear deformation theories, and more recently transverse shear warping functions, have been propo…

Transverse shear warping functions for anisotropic multilayered plates

2012

In this work, transverse shear warping functions for an equivalent single layer plate model are formulated from a variational approach. The part of the strain energy which involves the shear phenomenon is expressed in function of the warping functions and their derivatives. The variational calculus leads to a differential system of equations which warping functions must verify. Solving this system requires the choice of values for the (global) shear strains and their derivatives. A particular choice, which is justified for cross-ply laminates, leads to excellent results. For single layer isotropic and orthotropic plates, an analytical expression of the warping functions is given. They invol…

Damping performance of finite microperforated plates using multi-sized and spacial distributions of perforations

2023

In the context of structural dynamics, recent works by the authors showed that microperforations can be used to mitigate vibration. Microperforated plates (MPPs) have been shown to exhibit substantial added damping stemming from fluid-structure interactions and visco-thermal effect mechanisms in the boundary layers of the perforations during relative motion between the solid and the fluid contained in the perforations. The added damping reaches a maximum for a characteristic frequency, depending only on the perforation diameter. Choosing the perforation diameter so that the characteristic frequency coincides with the natural frequency of the plate reduces the mode contribution of the plate.…

Self-healing silk from the sea: role of helical hierarchical structure inPinna nobilisbyssus mechanics

2019

11 pages; International audience; The byssus fibers of Mytilus mussel species have become an important role model in bioinspired materials research due to their impressive properties (e.g. high toughness, self-healing); however, Mytilids represent only a small subset of all byssus-producing bivalves. Recent studies have revealed that byssus from other species possess completely different protein composition and hierarchical structure. In this regard, Pinna nobilis byssus is especially interesting due to its very different morphology, function and its historical use for weaving lightweight golden fabrics, known as sea silk. P. nobilis byssus was recently discovered to be comprised of globula…