Animal Models of Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD), once thought to be a degenerative disease, is now recognized to be an active pathobiological process, with chronic inflammation emerging as a predominant, and possibly driving, factor. However, many details of the pathobiological mechanisms of CAVD remain to be described, and new approaches to treat CAVD need to be identified. Animal models are emerging as vital tools to this end, facilitated by the advent of new models and improved understanding of the utility of existing models. In this paper, we summarize and critically appraise current small and large animal models of CAVD, discuss the utility of animal models for priority CAVD research areas, and provide recommendations for future animal model studies of CAVD

Hexanitrohexaazaisowurtzitane or CL-20 in India: Synthesis and Characterisation

Hexanitrohexaazaisowurtzitane (HNIW) more commonly called CL-20, the highest density and the most powerful real world explosive, has been made with very high yield and a high product purity. CL-20 is thoroughly characterised by spectral data (IR, NMR and mass) along with electron spectroscopy for chemical analysis (ESCA) and X-ray diffractogram. Furthermore, small-scale sensitivity tests have also been carried out

Padronização das técnicas de processamento e extração de RNA viral de amostras de sêmen caprino.

O sêmen se mostrou uma amostra adequada para a detecção de RNA genômico do vírus da artrite-encefalite caprina; As sucessivas lavagens com PBS estéril foram eficientes para a retirada do fluido seminal do restante dos componentes celulares; A incubação do sêmen fresco a 60°C por 30 minutos, após a homogenização em solução denaturante, foi eficiente para a dissolução protéica e inibição de Rnases, sendo adequada para iniciar o protocolo de extração de RNA viral de amostras de sêmen

Padronização das técnicas de processamento e extração de RNA viral de amostras de líquido sinovial.

O LS se mostrou uma amostra adequada para a detecção de RNA genômico do vírus da artrite-encefalite caprina. A centrifugação refrigerada por 30 minutos das amostras de LS se mostrou adequada para a sedimentação e isolamento de células caprinas e RNA livre do vírus, não acarretando em degradação significativa do último por Rnases

COMPARISON OF ANALYTICAL AND FINITE ELEMENT IMPLEMENTATION OF EXPONENTIAL CONSTITUTIVE MODELS FOR VALVE TISSUE UNDER MICROPIPETTE ASPIRATION SBC2010-19245

INTROUDUCTION Micropipette aspiration (MA) has been widely used to measure the biomechanical properties of cells and biomaterials The goal of this study was to determine whether aortic valve tissue material parameters estimated by the easily-implemented analytical approach [3] differ from those obtained by finite element (FE) analysis aortic valve tissue under MA. To do so, we implemented an exponential hyperelastic constitutive model in the FE model and used an inverse FE approach to predict material parameters METHODS AND MATERIALS Material models To fit the MA experimental measurements of the embryonic atrioventricular cushions, Butcher et al. implemented an exponential constitutive model [2] where W is the strain energy, C and α are material constants and E is the Green's finite strain with the 2 nd Piola-Kirchoff stress (S) being calculated by S = ∂W/∂E. To relate the stress and strain in the constitutive model to experimental measurements, Butcher et al. directly assigned the measured aspiration length (L) to pipette radius (a) ratio as the Green's strain, and the measured aspiration pressure ΔP as the Lagrangian stress T, which is calculated by T = λS with the stretch ratio in the aspiration direction (λ) given by λ = (E + 1) 0.5 To account for the multicomponent stress-strain field in the valve tissue during MA process, we implemented an incompressible isotropic exponential constitutive model. The strain energy density function of this model is expressed as where W is the strain energy, C and α are material constants and I 1 is the first strain invariant, defined as I 1 = with λ 1 , λ 2 and λ 3 being the principal stretches. This isotropic exponential constitutiv