Search results for "DAMP"

2017

Better identification of severe acute graft-versus-host disease (GvHD) may improve the outcome of this life-threatening complication of allogeneic hematopoietic stem cell transplantation. GvHD induces tissue damage and the release of damage-associated molecular pattern (DAMP) molecules. Here, we analyzed GvHD patients (n = 39) to show that serum heat shock protein glycoprotein 96 (Gp96) could be such a DAMP molecule. We demonstrate that serum Gp96 increases in gastrointestinal GvHD patients and its level correlates with disease severity. An increase in Gp96 serum level was also observed in a mouse model of acute GvHD. This model was used to identify complement C3 as a main partner of Gp96 i…

Ageing: from inflammation to cancer.

2018

Abstract Ageing is the major risk factor for cancer development. Hallmark of the ageing process is represented by inflammaging, which is a chronic and systemic low-grade inflammatory process. Inflammation is also a hallmark of cancer and is widely recognized to influence all cancer stages from cell transformation to metastasis. Therefore, inflammaging may represent the biological phenomena able to couple ageing process with cancer development. Here we review the molecular and cellular pathway involved in age-related chronic inflammation along with its potential triggers and their connection with cancer development.

2014

In this paper mathematical modeling of a vehicle crash test based on a single-mass is studied. The model under consideration consists of a single-mass coupled with a spring and/or a damper. The parameters for the spring and damper are obtained by analyzing the measured acceleration in the center of gravity of the vehicle during a crash. A model with a nonlinear spring and damper is also proposed and the parameters will be optimized with different damper and spring characteristics and optimization algorithms. The optimization algorithms used are interior-point and firefly algorithm. The objective of this paper is to compare different methods used to establish a simple model of a car crash an…

Optimal Damping Constant Investigation on a Quarter-Car

2013

This paper shows an investigation on optimal damping constant performed in the frequency domain. The optimal damping constant is meant as that value that minimizes the acceleration of all connected bodies characterizing a two degree of freedom system sketching a quarter car. The connected bodies are sprung and unsprung mass respectively for quarter of chassis and tire, this last keeps the contact with the ground and it is connected with the sprung mass through a shock absorber characterized by spring and fluid damper. Optimal damping constant was determined by imposing analytical conditions on the expression of acceleration of two masses. Afterwards, the variation of acceleration and positi…

Complex power distribution analysis in plates covered with passive constrained layer damping patches

2012

International audience; The vibration of a plate partially covered with a passive constrained layer damping (PCLD) patch is studied from an energetic point of view. The damped plate is excited by an acoustic plane wave. The study is done with a numerical two-dimensional multilayer plate model. Results of the present model are compared to those obtained with three-dimensional finite element models. It is shown that the present model gives accurate results, even for the layer's inner behavior. It is less expansive in terms of computational cost; hence, it can simulate efficiently the structure for higher frequencies. Mathematical formulas for complex mechanical power are presented, and the li…

Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects.

2012

Purpose: To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Subjects: Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20e62) volunteered. Methods: A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. Results: The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7e12.1) %, and in the compliance parameter, � 7.5 (� 9.8 to � 5.3) %. Response…

Dynamic Mechanical Behavior Analysis of Flax/Jute Fiber-Reinforced Composites under Salt-Fog Spray Environment

2020

Over the last decades, natural fiber-reinforced polymer composites (NFRPs) gained great attention in several engineering fields thanks to the reduction of the environmental impact and the end-of-life cost disposal. Unfortunately, the use of NFRPs is limited, mainly due to their weak resistance against humid environments. Since limited literature is available about the evolution of the dynamic mechanical response of NFRPs under aggressive environments, this paper aims to investigate the damping properties of flax, jute and flax/jute epoxy composites exposed to salt-fog up to 60 days. Furthermore, sodium bicarbonate fiber treatment was performed to improve the composites&rsquo

Generalized power-angle control for grid-forming converters: A structural analysis

2022

Several control schemes have been recently proposed and studied as grid-forming controls for power converters. In all these schemes, the power-angle control loop is the part which defines the fundamental capabilities of the grid-forming control: that control loop governs in fact the inherent synchronization mechanism of the power converter, the power sharing with the other generation sources in the system and the oscillatory characteristics of the converter-based resource. This article introduces a general formulation for the power-angle control characterizing the grid-forming concept for power converters. The generalized power-angle control is based on a polynomial fraction formulation, an…

A COMPARATIVE STUDY OF PHENOMENOLOGICAL MODELS OF MR BRAKE BASED ON NEURAL NETWORKS APPROACH

2013

In this paper a full-scale commercially available magnetorheological (MR) brake installed in a semi-active suspension (SAS) system is modeled and simulated. Two well-known phenomenological hysteresis models are explored: Bouc–Wen and Dahl ones. In particular, influence of their parameters on the response is evaluated and assessed. The next step is to introduce the artificial neural networks and discuss their application in the field of systems identification. Subsequently, two feedforward neural networks are created and trained to estimate parameters characterizing each of the MR damper models described. The semi-active suspension (SAS) system equipped with a MR brake is described and the …

A bending theory of thermoelastic diffusion plates based on Green-Naghdi theory

2017

Abstract This article is concerned with bending plate theory for thermoelastic diffusion materials under Green-Naghdi theory. First, we present the basic equations which characterize the bending of thin thermoelastic diffusion plates for type II and III models. The theory allows for the effect of transverse shear deformation without any shear correction factor, and permits the propagation of waves at a finite speed without energy dissipation for type II model and with energy dissipation for type III model. By the semigroup theory of linear operators, we prove the well-posedness of the both models and the asymptotic behavior of the solutions of type III model. For unbounded plate of type III…