Wyniki wyszukiwania - BazTech

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T-cell proliferation on immunopathogenic mechanism of psoriasis: a control based theoretical approach

Datta A., Roy P. K.

Control and Cybernetics

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2013

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Vol. 42, no. 2

365--386

EN

Psoriasis vulgaris is a common, worldwide autoimmune skin disorder characterized by T-cells mediated hyperproliferation of keratinocytes. The feature of T-cells arbitrated psoriatic lesions is the epidermal infiltration of oligoclonal CD8+ T-cells and also of CD4+ T-cells in the dermis. Psoriatic scratches are identified by red and enlarged lesions along with silver whitish scales. In this article, we propose a mathematical model for psoriasis, involving a set of differential equations, concerning T-cells, dendritic cells and epidermal keratinocytes. We introduce T-cell proliferation in the system, where T-cells are generated through expansion of accessible CD4+ T-cells from precursors. We are interested in observing how the cell biological system develops through T-cell proliferation in presence of control with respect to T-cells and keratinocytes. We study the model in both implicit and explicit ways and measure the effect of drug on the system through impulsive drug therapy.

2

Use of Quantitative Ultrasound to Measure Acoustic Properties of Human Skin

Piotrzkowska H., Litniewski J., Lewandowski M., Szymańska E., Nowicki A.

Archives of Acoustics

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2009

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Vol. 34, No. 4

471-480

EN

The scattering of ultrasonic waves depends on the size, shape, acoustical properties and concentration of scatterers in the tissue. The spectrum of the ultrasonic backscatter can be used to characterize non-invasively the structural and mechanical properties of tissue. We intend to apply the custom-designed high-frequency ultrasonic scanner for the skin and cutaneous lesions characterization by evaluating their attenuating and scattering properties. In this pilot study, we have explored the possibility of extracting the human skin backscattering coefficient (BC) from the ultrasonic B-scans obtained in vivo at 20–30 MHz. The measured BC values of normal skin (dermis) agree well with the published data. We have found also that the spatial resolution of the BC determination using our scanner is sufficient (aprox. 1 mm2) to characterize small skin lesions and assess their penetration depth.

3

Estimation of epidermis and dermis thicknesses on the basis of skin surface temperature

Majchrzak E., Jasiński M.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

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2006

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Vol. 5, nr 1

124-133

EN

Heat transfer in the skin tissue is treated as a multi-layer domain in which one can distinguish the epidermis, dermis and subcutaneous region is described by the system of Pennes equations and adequate boundary, initial and geometrical conditions. Many of the parameters used in the mathematical model are difficult to measure, e.g. epidermis or dermis thickness. In the paper the numerical algorithm of these geometrical parameters identification is presented in which the knowledge of skin surface temperature is assumed.