Search results for "tomography"

New Data from Pleistocene deposit of S. Ciro cave

2014

Quaternary fossil sites in Sicily have been known for a long time and all of them have a common story of human predation and manipulation. Hence, we illustrate the first electrical tomography applied to the study of a fossiliferous deposit in a cave in Sicily. The site investigated is the deposit inside the cave of San Ciro-Maredolce, near Palermo. This study aims to answer the following questions: is the geoelectric survey applicable to quaternary deposit of caves? is the deposit still existing or has been completely emptied? Here we show a ERT model (Electrical Resistivy Tomography) of deposit and possible anthropogenic interactions (presence of historic and\or illegal excavations) with t…

Fracture Shape and Orientation Contributions to P-Wave Velocity and Anisotropy of Alpine Fault Mylonites

2021

P-wave anisotropy is significant in the mylonitic Alpine Fault shear zone. Mineral- and texture-induced anisotropy are dominant in these rocks but further complicated by the presence of fractures. Electron back-scattered diffraction and synchrotron X-ray microtomography (micro-CT) data are acquired on exhumed schist, protomylonite, mylonite and ultramylonite samples to quantify mineral phases, crystal preferred orientations, microfractures and porosity. The samples are composed of quartz, plagioclase, mica and accessory garnet, and contain 3-5% porosity. Based on the micro-CT data, the representative pore shape has an aspect ratio of 5:2:1. Two numerical models are compared to calculate the…

Structural insights into M2O-Al2O3-WO3 (M = Na, K) system by electron diffraction tomography.

2015

TheM2O–Al2O3–WO3(M= alkaline metals) system has attracted the attention of the scientific community because some of its members showed potential applications as single crystalline media for tunable solid-state lasers. These materials behave as promising laser host materials due to their high and continuous transparency in the wide range of the near-IR region. A systematic investigation of these phases is nonetheless hampered because it is impossible to produce large crystals and only in a few cases a pure synthetic product can be achieved. Despite substantial advances in X-ray powder diffraction methods, structure investigation on nanoscale is still challenging, especially when the sample i…

Algorithms and software for biological multiscale image analysis

2013

A plasma protein corona enhances the biocompatibility of Au@Fe3O4 Janus particles

2015

AbstractAu@Fe3O4 Janus particles (JPs) are heteroparticles with discrete domains defined by different materials. Their tunable composition and morphology confer multimodal and versatile capabilities for use as contrast agents and drug carriers in future medicine. Au@Fe3O4 JPs have colloidal properties and surface characteristics leading to interactions with proteins in biological fluids. The resulting protein adsorption layer (“protein corona”) critically affects their interaction with living matter. Although Au@Fe3O4 JPs displayed good biocompatibility in a standardized in vitro situation, an in-depth characterization of the protein corona is of prime importance to unravel underlying mecha…

MR-Tomographie bei Hodenprozessen

1992

The value of T1-weighted sequences after intravenous administration of Gd-DTPA and of T2-weighted sequences was compared in 43 patients suspected of having scrotal abnormalities. T2-weighted sequences gave better demonstration of the tunica albuginea and better contrast between tumor and parenchyma. The two techniques were equally sensitive for demonstrating testicular tumors but orchitis was better demonstrated on the contrast enhanced sequences. Motion artifacts were less marked in the T1-weighted sequences with contrast enhancement. In selected cases, contrast enhancement may be a valuable addition to native protocols. Our experience has indicated that MRI provides specific findings in c…

Comparative Analysis of Root Canal Dentin Removal Capacity of Two NiTi Endodontic Reciprocating Systems for the Root Canal Treatment of Primary Molar…

2022

The objective of the present study was to evaluate and compare the dentin removal capacity of Endogal Kids and Reciproc Blue NiTi alloy endodontic reciprocating systems for root canal treatments in primary second molar teeth via a micro-computed tomography (micro-CT) scan. Materials and Methods: Sixty root canal systems in fifteen primary second molar teeth were chosen and classified into one of the following study groups: A: EK3 Endogal Kids (n = 30) (EDG) and B. R25 Reciproc Blue (n = 30) (RB). Preoperative and postoperative micro-CT scans were uploaded into image processing software to analyze the changes in the volume of root canal dentin using a mathematical algorithm that enabled prog…

Comparison of the accumulation of fibre breaks occurring in a unidirectional carbon/epoxy composite identified in a multi-scale micro-mechanical mode…

2010

National audience; A model to predict fibre break accumulation that takes into account all physical phenomena at the origin of the fibre break (i.e. the random nature, stress transfer due to breaks, fibre debonding and viscosity of the matrix) shows clearly that the failure of a unidirectional composite structure results in the formation of random fibre breaks which at higher loads coalesce into clusters of broken fibres. The object of the study is to experimentally confirm this scenario. Many techniques exist to detect the failure of carbon fibre composites, however none of them offer a resolution that allows this goal to be achieved in a non-destructive manner and in three dimensions. Hig…

Periodontal health in a population with Parkinson's disease in Spain: a cross-sectional study.

2022

Background: The aim of this research is to evaluate the periodontal health of patients with Parkinson Disease (PD) in a Spanish cohort. Material and Methods: A cross-sectional study was performed on 104 patients with PD (mean age: 66.19+9.3 years) and 106 controls (mean age: 59.26+14.11 years). A pre-designed clinical protocol was implemented, which included a standardized epidemiological index for periodontal disease (CPITN), clinical attachment loss (CAL), tooth-loss, full mouth plaque index (FMPI), and oral hygienic habits. Univariate descriptions and comparative analysis were performed. Results: The majority of PD patients presented good oral hygienic habits. There were no significant d…

A fully automatic method for biological target volume segmentation of brain metastases

2016

Leksell Gamma Knife is a mini-invasive technique to obtain a complete destruction of cerebral lesions delivering a single high dose radiation beam. Positron Emission Tomography (PET) imaging is increasingly utilized for radiation treatment planning. Nevertheless, lesion volume delineation in PET datasets is challenging because of the low spatial resolution and high noise level of PET images. Nowadays, the biological target volume (BTV) is manually contoured on PET studies. This procedure is time expensive and operator-dependent. In this article, a fully automatic algorithm for the BTV delineation based on random walks (RW) on graphs is proposed. The results are compared with the outcomes of…