Search results for "Contrast"
showing 10 items of 1162 documents
Subcutaneous Veins Depth Estimation Method Using Monte Carlo Simulations
2015
International audience; Subcutaneous veins localization is basic and important step for any intravenous medication administration. Due to different physiological characteristics, mainly darker skin tone, scars or dehydrated condition of patients, medical staff face difficulty in veins localization. Through near infrared imaging technology the veins can be visualized due to high contrast between veins and skin tissue in this modality. Information on the depth of veins is equally important for proper catheterization or venipuncture procedures. Patients have different veins depth due to the different amount of fat present in the subcutaneous layer. The depth of veins from the skin surface cann…
Neurodidattica e apprendimento di lingue tipologicamente affini: italiano e spagnolo
2013
Il capitolo tratta in primis della Neurodidattica come trandisciplina, accenna ai concetti di Neurofisiologia e apprendimento, di Bimodalità, Intermodalità e Lateralizzazione,per poi passare alla disquisizione di concetti quali la Neurofisiologia dell’apprendimento linguistico. Tutta questa trattazione è propedeutica alla presentazione dello spagnolo come lingua seconda, della sua localizzazione nel cervello. Si esaminano, inoltre, i concetti di interlingua e interferenza in contesti italofoni. Infine si procede all'analisi della Lingüística perceptiva ed alla sua possibile applicazione all'acquisizione dello spagnolo come L2.
A module for syntactic processing in music?
2006
Music and language have rules governing the structural organization of events. By analogy to language, these rules are referred to as the ‘syntactic rules’ of music. Does this analogy imply that the brain actually performs syntactic computations on musical structures, similar to those for language and based on a specialized module [1–3]? In contrast to linguistic syntax, which involves abstract computation between words, rules governing musical syntax are rooted in psychoacoustic properties of sound: syntactically related events are related on a sensory level and involve only weak acoustical deviance.
Compatibility of epirubicin-loaded DC bead™ with different non-ionic contrast media
2016
Purpose The aim of this study was to determine the compatibility of epirubicin-loaded DC bead™ with different non-ionic contrast media over a period of seven days when stored light protected under refrigerated conditions. Methods DC bead™ (2 ml) (Biocompatibles UK Ltd) of the bead size 70–150 µm ( = DC bead M1) or bead size 100–300 µm were loaded with 75 mg epirubicin powder formulation (Farmorubicin® dissolved in 3 ml water for injection to a concentration of 25 mg/ml) or 76 mg epirubicin injection solution (Epimedac® 2 mg/ml) within 2 h or 6 h, respectively. After removal of the excess solution, the epirubicin-loaded beads were mixed in polypropylene syringes with an equal volume (∼1.5 ml…
A Sliding Window-Based Method to Detect Selective Constraints in Protein-Coding Genes and Its Application to RNA Viruses
2002
Here we present a new sliding window-based method specially designed to detect selective constraints in specific regions of a multiple protein-coding sequence alignment. In contrast to previous window-based procedures, our method is based on a nonarbitrary statistical approach to find the appropriate codon-window size to test deviations of synonymous (d(S)) and nonsynonymous (d(N)) nucleotide substitutions from the expectation. The probabilities of d(N) and d(S) are obtained from simulated data and used to detect significant deviations of d(N) and d(S) in a specific window region of the real sequence alignment. The nonsynonymous-to-synonymous rate ratio (w = d(N)/d(S)) was used to highlight…
Optimal control design of preparation pulses for contrast optimization in MRI
2017
Abstract This work investigates the use of MRI radio-frequency (RF) pulses designed within the framework of optimal control theory for image contrast optimization. The magnetization evolution is modeled with Bloch equations, which defines a dynamic system that can be controlled via the application of the Pontryagin Maximum Principle (PMP). This framework allows the computation of optimal RF pulses that bring the magnetization to a given state to obtain the desired contrast after acquisition. Creating contrast through the optimal manipulation of Bloch equations is a new way of handling contrast in MRI, which can explore the theoretical limits of the system. Simulation experiments carried out…
DNP in MRI: an in-bore approach at 1.5 T.
2011
Abstract We have used liquid state (“Overhauser”) Dynamic Nuclear Polarization (DNP) to significantly enhance the signal to noise ratio (SNR) of Magnetic Resonance Imaging (MRI). For the first time this was achieved by hyperpolarizing directly in the MRI-scanner field of 1.5 T in continuous flow mode and immediately delivering the hyperpolarized substance to the imaging site to ensure maximum contrast between hyperpolarized sample and sample at thermal polarization. We achieve a maximum absolute signal enhancement factor of 98; while the hyperpolarized sample is transported at a flow rate of up to 30 ml/h yielding an average flow speed up to 470 mm/s over a distance of approximately 80 mm. …
Revisiting the D-meson hadroproduction in general-mass variable flavour number scheme
2018
We introduce a novel realization of the open heavy-flavour hadroproduction in general-mass variable flavour number scheme at next-to-leading order in perturbative QCD. The principal novelty with respect to the earlier works is in the treatment of small-transverse-momentum limit, which has been a particularly challenging kinematic region in the past. We show that by a suitable choice of scheme, it is possible to obtain a well-behaved description of the open heavy-flavour hadroproduction cross sections from zero up to asymptotically high transverse momentum. We contrast our calculation with the available D$^0$-meson data as measured by the LHCb and ALICE collaborations at the LHC, finding a v…
EASL Clinical Practice Guidelines: Management of hepatocellular carcinoma
2018
Liver cancer is the fifth most common cancer and the second most frequent cause of cancer-related death globally. Hepatocellular carcinoma represents about 90% of primary liver cancers and constitutes a major global health problem. The following Clinical Practice Guidelines will give up-to-date advice for the clinical management of patients with hepatocellular carcinoma, as well as providing an in-depth review of all the relevant data leading to the conclusions herein. (C) 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.