Search results for "MR"
showing 10 items of 3001 documents
Tracking of blood vessels motion from 4D-flow MRI data
2022
This paper presents a novel approach to track objects from 4D Flow MRI data. A salient feature of the proposed method is that it fully exploits the geometrical and dynamical nature of the information provided by this imaging modality. The underlying idea consists in formulating the tracking problem as a data assimilation problem, in which both position and velocity observations are extracted from the 4D Flow MRI data series. Optimal estate estimation is then performed in a sequential fashion via Kalman filtering. The capabilities of the method are extensively assessed in a numerical study involving synthetic and clinical data.
Post-Transcriptional Regulation of Iron Homeostasis in Saccharomyces cerevisiae
2013
Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox cofactor in a wide variety of biological processes. Recent studies in Saccharomyces cerevisiae have shown that in response to iron deficiency, an RNA-binding protein denoted Cth2 coordinates a global metabolic rearrangement that aims to optimize iron utilization. The Cth2 protein contains two Cx8Cx5Cx3H tandem zinc fingers (TZFs) that specifically bind to adenosine/uridine-rich elements within the 3' untranslated region of many mRNAs to promote their degradation. The Cth2 protein shuttles between the nucleus and the cytoplasm. Once inside the nucleus, Cth2 binds target mRNAs and stimulate…
An extensive pattern of atypical neural speech-sound discrimination in newborns at risk of dyslexia.
2019
Objective: Identifying early signs of developmental dyslexia, associated with deficient speech-sound processing, is paramount to establish early interventions. We aimed to find early speech-sound processing deficiencies in dyslexia, expecting diminished and atypically lateralized event-related potentials (ERP) and mismatch responses (MMR) in newborns at dyslexia risk. Methods: ERPs were recorded to a pseudoword and its variants (vowel-duration, vowel-identity, and syllable-frequency changes) from 88 newborns at high or no familial risk. The response significance was tested, and group, laterality, and frontality effects were assessed with repeated-measures ANOVA. Results: An early positive a…
Room temperature ionic liquids based on cationic porphyrin derivatives and tetrakis(pentafluorophenyl)borate anion
2011
A series of 11 low melting ionic liquids based on meso-substituted A3B -porphyrins and A2B2-porphyrins containing one or two pyridyl substituents have been synthesized in high yields. Three of them are liquids at room temperature. All these porphyrinic salts were characterized by1H NMR,19F NMR, MALDI-TOF mass spectrometry, elemental analysis and UV-visible spectroscopy. The thermal properties and conductivity values of these salt derivatives have been also measured. A specific conductivity value of up to 4 mS.cm-1could be obtained for a compound having the counter-anion B(C6F5)4-.
Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo
2021
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells v…
Strategies to gain novel Alzheimer’s disease diagnostics and therapeutics using modulators of ABCA transporters
2021
Adenosine-triphosphate-(ATP)-binding cassette (ABC) transport proteins are ubiquitously present membrane-bound efflux pumps that distribute endo- and xenobiotics across intra- and intercellular barriers. Discovered over 40 years ago, ABC transporters have been identified as key players in various human diseases, such as multidrug-resistant cancer and atherosclerosis, but also neurodegenerative diseases, such as Alzheimer���s disease (AD). Most prominent and well-studied are ABCB1, ABCC1, and ABCG2, not only due to their contribution to the multidrug resistance (MDR) phenotype in cancer, but also due to their contribution to AD. However, our understanding of other ABC transporters is limited…
Musically induced ASMR : an amalgamated experience
2015
Musically induced ASMR is an Autonomous Sensory Meridian Response triggered by music. The term ASMR is best known on the internet by communities who report experiencing this phenomenon. It is most simply understood as an experience like musical chills, however can be triggered by nearly any form of stimuli. The current study employed grounded theory, a meticulous and established qualitative research method for developing theory that serves to explain salient characteristics of a particular phenomenon; to theorize the nature and significance of musically induced ASMR and ASMR in general. Based on the data collected, the study confirmed the existence of musically induced ASMR and demonstrates…
The Intention-to-Treat Effect of Bridging Treatments in the Setting of Milan Criteria–In Patients Waiting for Liver Transplantation
2019
In patients with hepatocellular carcinoma (HCC) meeting the Milan criteria (MC), the benefit of locoregional therapies (LRTs) in the context of liver transplantation (LT) is still debated. Initial biases in the selection between treated and untreated patients have yielded conflicting reported results. The study aimed to identify, using a competing risk analysis, risk factors for HCC-dependent LT failure, defined as pretransplant tumor-related delisting or posttransplant recurrence. The study was registered at www.clinicaltrials.gov (identification number NCT03723304). In order to offset the initial limitations of the investigated population, an inverse probability of treatment weighting (IP…
Lanthanide–saccharide chemistry: synthesis and characterisation of Ce(III)–saccharide complexes
2000
A series of nine Ce(III) complexes has been synthesised with seven different monosaccharides (D-glucose, D-fructose, D-galactose, D-mannose, L-sorbose, D-ribose and D-xylose) and two different disaccharides (D-maltose and L-lactose), and these have been characterised with various analytical, spectral, magnetic and electrochemical techniques. The NMR studies have highlighted some interesting features about the metal-ion-binding pattern of the saccharides. Some additional coordination has been proposed along with the chelating groups in the saccharide molecules, based on the shifts in 13C NMR spectra. On the other hand, solution absorption studies and solid-state magnetic susceptibilities hav…
<title>Ion and electron trapping: release and relaxation processes in fluoride crystals</title>
2001
The thermally stimulated relaxation (TSR) processes in CaF2, BaF2 and LiBaF3 crystals (X-ray irradiated at LNT or RT) have been investigated by means of the ionic conductivity, thermally stimulated (TS) ionic depolarization current (TSDC), TS current (TSC), TS luminescence (TSL) and thermal bleaching techniques. The ionic TSDC measurements evidence that under DC field fluorides accumulate large ionic space-charge (thermoelectric state is formed) as a result of the migrating anion interstitial and/or vacancy capture on defects. In the ionic conductivity region (290 - 650 K) the thermoelectric state anneals, and several wide and overlapping anionic TSDC peaks are detected. The ionic TSDC stag…