Search results for " Matrix"

A sliding mode approach to robust stabilisation of Markovian jump linear time-delay systems with generally incomplete transition rates

2015

Abstract This paper is devoted to investigating the problem of robust sliding mode control for a class of uncertain Markovian jump linear time-delay systems with generally uncertain transition rates (GUTRs). In this GUTR model, each transition rate can be completely unknown or only its estimate value is known. By making use of linear matrix inequalities technique, sufficient conditions are presented to derive the linear switching surface and guarantee the stochastic stability of sliding mode dynamics. A sliding mode control law is developed to drive the state trajectory of the closed-loop system to the specified linear switching surface in a finite-time interval in spite of the existing unc…

Isolated roundings and flattenings of submanifolds in Euclidean spaces

2005

We introduce the concepts of rounding and flattening of a smooth map $g$ of an $m$-dimensional manifold $M$ to the euclidean space $\R^n$ with $m<n$, as those points in $M$ such that the image $g(M)$ has contact of type $\Sigma^{m,\dots,m}$ with a hypersphere or a hyperplane of $\R^n$, respectively. This includes several known special points such as vertices or flattenings of a curve in $\R^n$, umbilics of a surface in $\R^3$, or inflections of a surface in $\R^4$.

Surface Reflectance: An Optical Method for Multiscale Curvature Characterization of Wear on Ceramic–Metal Composites

2020

Surface gradient characterization by light reflectance (SGCLR) is used for the first time for multiscale curvature calculations and discrimination of worn surfaces on six damaged ceramic&ndash

The effect of detergents on the basement membrane complex of a biologic scaffold material

2013

The basement membrane complex (BMC) is a critical component of the extracellular matrix (ECM) that supports and facilitates the growth of cells. This study investigates four detergents commonly used in the process of tissue decellularization and their effect upon the BMC. The BMC of porcine urinary bladder was subjected to 3% Triton-X 100, 8 mM 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS), 4% sodium deoxycholate or 1% sodium dodecyl sulfate (SDS) for 24 h. The BMC structure for each treatment group was assessed by immunolabeling, scanning electron microscopy (SEM) and second harmonic generation (SHG) imaging of the fiber network. The composition was assessed by quantif…

A multi-methodology and sustainability-supporting framework for implementation and assessment of a holistic building renovation

La ristrutturazione degli edifici in futuro dovrà essere condotta secondo una prospettiva più olistica legata alla sostenibilità vista in una più ampia gamma di obiettivi/criteri e facilitata dagli scenari di ristrutturazione possibili. La ristrutturazione degli edifici dovrebbe servire a migliorarne le performance al fine di soddisfare le esigenze degli utenti, rendendo questi ultimi meno vulnerabili in relazione ai futuri costi energetici. Vi è un grande potenziale per ridurre il consumo di energia negli edifici esistenti. Tuttavia, ciò non deve comprometterè i valori architettonici e di qualità che rendono particolari. Pertanto, non possono essere semplicemente rinnovati, ma devono subir…

Solubilized liver extracellular matrix maintains primary rat hepatocyte phenotype in-vitro.

2015

Whole organ engineering and cell-based regenerative medicine approaches are being investigated as potential therapeutic options for end-stage liver failure. However, a major challenge of these strategies is the loss of hepatic specific function after hepatocytes are removed from their native microenvironment. The objective of the present study was to determine if solubilized liver extracellular matrix (ECM), when used as a media supplement, can better maintain hepatocyte phenotype compared to type I collagen alone or solubilized ECM harvested from a non-liver tissue source. Liver extracellular matrix (LECM) from four different species was isolated via liver tissue decellularization, solubil…

A symmetric Galerkin BEM for plate bending analysis

2009

Abstract The Symmetric Galerkin Boundary Element Method is employed in thin plate bending analysis in accordance with the Love–Kirchhoff kinematical assumption. The equations are obtained through the stationary conditions of the total potential energy, written for a plate whose boundary is discretized in boundary elements. Since the matrix coefficients are made up as double integrals with high order singularities, a strategy is shown to compute these coefficients in closed form. Furthermore, in order to model the kinematical discontinuities and to weight the mechanical quantities along the boundary elements, the Lagrangian quadratic shape functions, rather than C 1 type (spline, Hermitian),…

Quantitation of antigen-reactive T cells in peripheral blood by IFNgamma-ELISPOT assay and chromium-release assay: a four-centre comparative trial

2000

The ELISPOT assay is increasingly being used for the monitoring of the induction of antigen-reactive T cells in cancer vaccination trials. In order to evaluate the reliability of T cell frequency analysis with the ELISPOT assay, a comparative study was performed in four European laboratories. Six samples from healthy subjects were analyzed for the frequency of influenza-reactive CD8+ T cells in peripheral blood mononuclear cells (PBMC) by IFNgamma-ELISPOT assay. In addition, one laboratory determined cytotoxic T cell precursor (CTL) frequencies in these samples by limiting dilution chromium-release assay (LDA), and three laboratories performed a variant of the LDA, the multiple microculture…

Identification of T cell epitopes by the use of rapidly generated mRNA fragments.

2004

Abstract Although the number of defined T cell epitopes of clinically relevant antigens is constantly increasing, there is still an enormous need to identify further peptides, processed from new antigens or presented by rare HLA molecules, respectively. Here we introduce a novel two-step approach for the rapid identification of T cell epitopes. It was established in the CMV infection model. From the peripheral blood of healthy donors sharing HLA-A1 according to HLA serotyping we isolated CD8 + T lymphocytes and generated dendritic cells (DCs). DCs were electroporated with CMV pp65 mRNA and tested for recognition by autologous CD8 + T lymphocytes in IFN-γ ELISPOT assays. In all 10 CMV-seropo…

The use of clonal mRNA as an antigenic format for the detection of antigen-specific T lymphocytes in IFN-gamma ELISPOT assays.

2003

Abstract Most assay systems for the quantification of antigen-specific T-cell responses in infectious, malignant and autoimmune disease depend on the peptide antigen format and are therefore restricted to known epitopes and their presenting HLA molecules. Here we tested in ELISPOT assays the application of in vitro-transcribed clonal mRNA as an alternative antigen format covering all potential epitopes of a given antigen. As model antigens, we chose pp65 of human cytomegalovirus (HCMV) and human tyrosinase (hTyr). Antigen-presenting cells (APC) were K562 cells stably transfected with single HLA class I alleles and autologous dendritic cells (DC). As effectors, we applied in vitro-generated …