Search results for " Tom"
showing 10 items of 1742 documents
Choroidal thickness and morphology analysed by optical coherence tomography as a method to approach diabetic ocular disease prognosis and progression
2019
TÍTULO ESPESOR COROIDEO Y MORFOLOGÍA ANALIZADO POR TOMOGRAFÍA DE COHERENCIA ÓPTICA COMO MÉTODO PARA ABORDAR LA PROGNOSIS Y LA PROGRESIÓN DE LA ENFERMEDAD OCULAR DIABÉTICA INTRODUCCIÓN La evidencia clínica in vivo de coroidopatía diabética (DC) ha sido difícil de demostrar clínicamente debido a la falta de medios para visualizar la coroides. Los avances de la tecnología de la tomografía de coherencia óptica (OCT) permitieron la visualización in vivo de la coroides. Los resultados controvertidos en la Diabetes para el grosor coroideo (CT) y la falta de identificación de los cambios morfológicos hacen que la DC identificada con OCT aún no se conozca. PROPÓSITO Evaluar si la medición por CT sol…
Korelācija starp dzimumu un radzenes biezumu
2020
Darbs ir uzrakstīts latviešu valodā uz 31 lapaspusēm. Tas satur 11 attēlus, 6 tabulas, 38 atsauces uz literatūras avotiem. Darba mērķis: Apskatīt cilvēka fizioloģisko parametru ietekmi uz radzenes biezuma mērījumiem, izanalizēt dzimuma ietekmi. Apskatīt un novērtēt radzenes biezuma mērīšanas metodes. Metode: Tika analizēts radzenes biezums 202 acīm, kas bija iegūts ar 2 dažādām pahimetrijas metodēm. Rezultāti: Radzenes centrālais un paracentrālais biezums vīriešiem ir nedaudz lielāks kā sievietēm, taču atšķirība nav statistiski nozīmīga. Labai acij starp pahimetrijas metodēm ir lielāka mērījumu atšķirība abās dzimumu grupās. Ir spēcīga korelācija starp abām pahimetrijas metodēm, bet tās nav…
Optiskās koherences tomogrāfijas pielietojums radzenes parametru novērtēšanā
2019
Bakalaura darbs ir uzrakstīts latviešu valodā uz 35 lapaspusēm. Tas satur 20 attēlus, 4 tabulas, un 39 atsauces uz literatūras avotiem. Mērķis: Salīdzināt radzenes parametrus dalībniekiem dažādās vecuma grupās. Metode: Tika veikti radzenes biezuma un radzenes epitēlija biezuma mērījumi 6 mm diametrā, izmantojot optiskās koherences tomogrāfu Topcon Maestro 3D. Mērījumu preciziātes salīdzināšanai radzenes centrālais biezums tika mērīts ar bezkontakta optisko pahimetru Topcon TRK-1P. Rezultāti: Radzenes biezums ir atšķirīgs centrā un virzienā uz perifēriju. Radzene ir biezāka nazālajā pusē (N, S, IN, SN) un plānāka temporālajā pusē (T, I, IT, ST). Radzenes epitēlija biezums centrā ir būtiski a…
OPTICAL COHERENCE TOMOGRAPHY ASSESSING OSCC: SOMETHING IN COMMON WITH MELANOMA?
2021
Diseño y puesta a punto de un método cefalométrico en 3D para el estudio de la población ortodóncica
2011
Introducción: La introducción de la tomografía computarizada de haz cónico (CBCT) y su aplicación clínica a la imagen craneofacial tridimensional (3D) supone una herramienta diagnóstica esencial para el clínico. Objetivos: 1-Evaluar la reproducibilidad en la localización de puntos cefalométricos pertenecientes a tejidos duros del cráneo sobre imágenes escaneadas con un equipo CBCT 2-Comprobar si los valores de diferentes mediciones de las reconstrucciones 3D del CBCT se pueden comparar a las mediciones realizadas sobre imágenes 2D de la telerradiografía lateral de cráneo y comparar también si existen diferencias entre dos tipos diferentes de software de CBCT. 3-Diseñar un método cefalométri…
The linearized Calderón problem for polyharmonic operators
2023
In this article we consider a linearized Calderón problem for polyharmonic operators of order 2m (m ≥ 2) in the spirit of Calderón’s original work [7]. We give a uniqueness result for determining coefficients of order ≤ 2m − 1 up to gauge, based on inverting momentum ray transforms. peerReviewed
Calderón's problem for p-laplace type equations
2016
We investigate a generalization of Calderón’s problem of recovering the conductivity coefficient in a conductivity equation from boundary measurements. As a model equation we consider the p-conductivity equation div σ |∇u|p−2 ∇u = 0 with 1 < p < ∞, which reduces to the standard conductivity equation when p = 2. The thesis consists of results on the direct problem, boundary determination and detecting inclusions. We formulate the equation as a variational problem also when the conductivity σ may be zero or infinity in large sets. As a boundary determination result we recover the first order derivative of a smooth conductivity on the boundary. We use the enclosure method of Ikehata to recover the…
Refined instability estimates for some inverse problems
2022
Many inverse problems are known to be ill-posed. The ill-posedness can be manifested by an instability estimate of exponential type, first derived by Mandache [29]. In this work, based on Mandache's idea, we refine the instability estimates for two inverse problems, including the inverse inclusion problem and the inverse scattering problem. Our aim is to derive explicitly the dependence of the instability estimates on key parameters. The first result of this work is to show how the instability depends on the depth of the hidden inclusion and the conductivity of the background medium. This work can be regarded as a counterpart of the depth-dependent and conductivity-dependent stability estim…
Partial Data Problems and Unique Continuation in Scalar and Vector Field Tomography
2022
AbstractWe prove that if P(D) is some constant coefficient partial differential operator and f is a scalar field such that P(D)f vanishes in a given open set, then the integrals of f over all lines intersecting that open set determine the scalar field uniquely everywhere. This is done by proving a unique continuation property of fractional Laplacians which implies uniqueness for the partial data problem. We also apply our results to partial data problems of vector fields.
A regional-scale discontinuity in western Sicily revealed by a multidisciplinary approach: A new piece for understanding the geodynamic puzzle of the…
2015
The results of an integrated stratigraphic, structural, geophysical, and geochemical study reveal the presence of a crustal discontinuity in western Sicily that, at present, runs roughly N-S along a band from San Vito Lo Capo to Sciacca. The boundary between the two zones of this discontinuity is nearly orthogonal to the main thrust propagation of the Sicilian thrust-and-fold belt. The different Permian to Tertiary sedimentary evolution recorded by the two zones appears related to this discontinuity, with thick carbonate platforms in the western sector facing deepwater successions in the eastern one. The presence of Upper Triassic reefs, huge megabreccia bodies, and widespread submarine vol…