Search results for "MRI"

58. White matter abnormalities in attention-deficit/hyperactivity disorder: A diffusion tensor imaging study in adult patients

2009

Clinical and Brain Imaging Findings in a Child with Vitamin B12 Deficiency

2021

Vitamin B12 (Vit-B12) deficiency is a rare and treatable cause of failure to thrive and delayed development in infants who are exclusively breastfed. Apart from genetic causes, it can be related to a malabsorption syndrome or when the mother follows a strict vegetarian or vegan diet, causing a low hepatic storage of Vit-B12 in the infant at birth. As the neurological symptoms are nonspecific, a brain magnetic resonance imaging (MRI) exam is usually performed to rule out primary causes of neurodevelopmental delay. Findings related to brain atrophy are usually observed. A favorable response is achieved with Vit-B12 therapy, and neurological symptoms dramatically improve within a few days afte…

A multicenter measurement of magnetization transfer ratio in normal white matter

1999

To assess the importance of intercenter variations when measuring magnetization transfer ratio (MTR) in the brain, six European centers measured MTR in normal white matter. MTR ranged from 9 to 51 percent units (25 sequences). The effective flip angle of the saturating pulse divided by the pulse repetition time (ENRsat degrees/msec) was a good predictor of MTR (MTR = 3.25 ENRsat).

Switching synchronization in one-dimensional memristive networks: An exact solution.

2017

We study a switching synchronization phenomenon taking place in one-dimensional memristive networks when the memristors switch from the high- to low-resistance state. It is assumed that the distributions of threshold voltages and switching rates of memristors are arbitrary. Using the Laplace transform, a set of nonlinear equations describing the memristors dynamics is solved exactly, without any approximations. The time dependencies of memristances are found, and it is shown that the voltage falls across memristors are proportional to their threshold voltages. A compact expression for the network switching time is derived.

Brain structural alterations in Fabry disease: ROI-based and voxel-based analyses of diffusion tensor imaging parameters

2007

Stability and Chaotic Attractors of Memristor-Based Circuit with a Line of Equilibria

2019

This report investigates the stability problem of memristive systems with a line of equilibria on the example of SBT memristor-based Wien-bridge circuit. For the considered system, conditions of local and global partial stability are obtained, and chaotic dynamics is studied. peerReviewed

Formulation predictive dissolution (fPD) testing to advance oral drug product development: an introduction to the US FDA funded ‘21st Century BA/BE’ …

2018

Over the past decade, formulation predictive dissolution (fPD) testing has gained increasing attention. Another mindset is pushed forward where scientists in our field are more confident to explore the in vivo behavior of an oral drug product by performing predictive in vitro dissolution studies. Similarly, there is an increasing interest in the application of modern computational fluid dynamics (CFD) frameworks and high-performance computing platforms to study the local processes underlying absorption within the gastrointestinal (GI) tract. In that way, CFD and computing platforms both can inform future PBPK-based in silico frameworks and determine the GI-motility-driven hydrodynamic impac…

Sadarbības prasmes sekmēšana 5-7 gadus veciem bērniem pētnieciskajā darbībā

2021

Kvalifikācijas darba autore , Ērika Preinberga, veica pētījumu ,,Sadarbības prasmes sekmēšana 5-7 gadus veciem bērniem pētnieciskajā darbībā”, lektores Mg. paed. Rūtas Vocišas vadībā. Kvalifikācijas darba mērķis: Izpētīt 5-7 gadus vecumu bērnu sadarbības prasmju sekmēšanu pētnieciskajā darbībā un apkopot ieteikumus 5-7 gadu vecu bērnu iespējām sadarbības prasmju sekmēšana pētnieciskajā darbībā. Darba uzdevumi: •Analizēt pedagoģisko un pedagoģiski psiholoģisko literatūru par sadarbības prasmi, pētniecisko darbību, 5-7 gadus vecu bērnu attīstības tendencēm; •Noteikt 5-7 gadus vecu bērnu sadarbības prasmes sekmēšanu pētnieciskajā darbībā reālajā pedagoģiskajā procesā; •Izpētī un apkopot ieteik…

Plantar fascia evaluation with a low-field MRI scanner in weight-bering position: our initial experience in patients with plantar fasciitis and in he…

2009

Purpose: To assess the usefulness of weight-bearing examination of the ankle performed with a low-field MRI scanner in the evaluation of plantar fascia in normal healthy volunteers and in patients with a clinical evidence of plantar fasciitis. Methods and Materials: We retrospectively evaluated ankle MR examinations in two groups of 40 patients each, performed between January and July 2008. Spin echo T1W, Gradient echo T2W, and Short Tau Inversion Recovery (STIR) images were acquired with a 0.2 T scanner (G-Scan, Esaote Biomedica, Genoa, Italy) in both weight-bearing position and normal conventional supine position. A dedicated extremities transmitter/receiver coil was used. The lesion site…

Synthèse de nouveaux agents bimodaux hydrosolubles pour l'IRM, l'imagerie nucléaire, l'imagerie biphotonique et la génération de second harmonique

2015

The goal of my PhD studies was to synthesize new compounds for possible medical imaging applications. The first part of my thesis focused on the synthesis of heteroleptic ligands to achieve the chelation of two different metals aimed at addressing two types of medical imaging. We first synthesized porphyrins, which are well-known for the chelation of numerous transition metals. We focused on copper, whose copper-64 isotope is a β+ emitter usable in Positron Emission Tomography (PET). These porphyrins have been coupled with a DOTA derivative. This molecule, metallated with gadolinium, is well-known in Magnetic Resonance Imaging (MRI). Our compounds display encouraging relaxivities for MRI ap…