Search results for "Matrix"

The indirect force method

1990

Abstract It is known that the matrix force method shows some advantages over the displacement method for certain classes of problems, particularly in optimization and in the stress concentration analysis. Notwithstanding this, few efforts have been made to employ this method in engineering problems. In this paper, within the elastic analysis of frames and trusses, the indirect force method, utilizing beam-node type finite elements, is proposed. This method is based on the kinematical and mechanical study of nodes and of beams, the latter connected with the nodes by their first extremes according to a preliminary arrangement. In this formulation kinematical singularities are included, in the…

Dissimilarity Application in Digitized Mammographic Images Classification.

2006

Purpose of this work is the development of an automatic classification system which could be useful for radiologists in the investigation of breast cancer. The software has been designed in the framework of the MAGIC-5 collaboration. In the traditional way of learning from examples of objects the classifiers are built in a feature space. However, an alternative ways can be found by constructing decision rules on dissimilarity (distance) representations. In such a recognition process a new object is described by its distances to (a subset of) the training samples. The use of the dissimilarities is especially of interest when features are difficult to obtain or when they have a little discrim…

Mappings of finite distortion: decay of the Jacobian in the plane

2008

Robust stabilisation of 2D state-delayed stochastic systems with randomly occurring uncertainties and nonlinearities

2013

This paper is concerned with the state feedback control problem for a class of two-dimensional (2D) discrete-time stochastic systems with time-delays, randomly occurring uncertainties and nonlinearities. Both the sector-like nonlinearities and the norm-bounded uncertainties enter into the system in random ways, and such randomly occurring uncertainties and nonlinearities obey certain mutually uncorrelated Bernoulli random binary distribution laws. Sufficient computationally tractable linear matrix inequality–based conditions are established for the 2D nonlinear stochastic time-delay systems to be asymptotically stable in the mean-square sense, and then the explicit expression of the desired…

Medium-Term Culture of Primary Oral Squamous Cell Carcinoma in a Three- Dimensional Model: Effects on Cell Survival Following Topical 5-Fluororacile …

2012

Since the activity of several conventional anticancer drugs is restricted by resistance mechanisms and dose-limiting side-effects, the design of formulations for local application on malignant lesions seems to be an efficient and promising drug delivery approach. In this study, the effect of locally applied 5-FU on cell death was evaluated both in a SCC4/HEK001 model and in a newly proposed 3D outgrowth model of oral squamous cell carcinoma (OSCC). Initially, the optimal drug dose was established by delivery of solutions containing different amounts of 5-FU. The solution containing 1% (w/v) of 5-FU resulted effective in inducing cell death with complete eradication of cell colonies. Buccal …

Determination of isoniazid and pyridoxine in plasma sample of tuberculosis patients by micellar liquid chromatography

2021

It is no doubt Isoniazid is a powerful tuberculosis drug, but it might give rise to Vitamin B6 (Pyridoxine) deficiency. In this case, a usual treatment is the combined administration of Isoniazid and Pyridoxine. An easy-to-conduct procedure based on Micellar Liquid Chromatography has been developed to quantify Isoniazid and Pyridoxine in plasma from Tuberculosis patients. The sample was diluted in mobile phase, filtered and directly injected, thus avoiding extraction or purification steps. Both drugs were adequately resolved from the matrix and endogenous compounds using a mobile phase made up of 0.15 M sodium dodecyl sulfate – 8%(v/v) 1-butanol – 0.01 M phosphate buffer at pH 3, running at…

Aloin delivery on buccal mucosa: ex vivo studies and design of a new locoregional dosing system

2014

Context: Chemoprevention of potential malignant disorders or cancerous lesions that affect oral mucosae requires extended duration of treatment. Locoregional delivery of natural products could represent a promising strategy for this purpose. Objective: To investigate the aptitude of aloin to permeate through, or accumulate in, the buccal mucosa and to develop a new prolonged oro-mucosal drug delivery system. Materials and Methods: Permeation/accumulation of aloin from Curacao Aloe (containing 50% barbaloin) was evaluated ex vivo, using porcine buccal mucosa as the most useful model to simulate human epithelium. Oro-mucosal matrix tablets were prepared by dispersing aloin (10% w/w) in Eudrag…

In VitroRelease of Local Anaesthetic and Anti-Inflammatory Drugs from Crosslinked Collagen Based Device

2012

The drug delivery systems that are the object of this article take the form of a hydrophilic matrix (collagen or crosslinked collagen) containing a drug. These devices can be used as The model active agents, were chosen from the range of local anaesthetics (lidocaine hydrochloride), anti-inflammatory (diclofenac sodium salt) and antioxydant (caffeic acid). Whatever the drug affinity for water, in the first time of the experiments, the release appears to be systematically delayed when the matrix is crosslinked. For lidocaine hydrochloride based systems, as the amount of drug increases in the matrix, the high gap concentration between the matrix and the buffer solution promote the diffusion a…

Mesoporous silicate as matrix for drug delivery systems of non-steroidal antinflammatory drugs

2002

Publisher Summary The suitability of a mesoporous silicate matrix as a drug-delivery system has been evaluated using different nonsteroid anti-inflammatory agents as model drugs. This type of matrix can trap the bioactive agents by a soaking procedure and then release them in conditions mimicking the biological fluids. The high affinity of these matrices for water makes them potentially biocompatible. A matrix impregnated with diflunisal can offer a good potential as a system for the controlled drug release. In fact, only 20% of the drug is released at the gastric level allowing, in this way, the reduction of side effects related to the oral administration of nonsteroidal anti-inflammatory …

MMP-10 Is Required for Efficient Muscle Regeneration in Mouse Models of Injury and Muscular Dystrophy

2013

Abstract Matrix metalloproteinases (MMPs), a family of endopeptidases that are involved in the degradation of extracellular matrix components, have been implicated in skeletal muscle regeneration. Among the MMPs, MMP-2 and MMP-9 are upregulated in Duchenne muscular dystrophy (DMD), a fatal X-linked muscle disorder. However, inhibition or overexpression of specific MMPs in a mouse model of DMD (mdx) has yielded mixed results regarding disease progression, depending on the MMP studied. Here, we have examined the role of MMP-10 in muscle regeneration during injury and muscular dystrophy. We found that skeletal muscle increases MMP-10 protein expression in response to damage (notexin) or diseas…