Search results for "MR"
showing 10 items of 3001 documents
Krāsu centru dimanta kristālā kodola spina polarizācija magnētiskajā laukā
2018
Šajā darbā tiek apskatīta lāzera un mikroviļņu lauku ietekme uz krāsu centriem dimanta kristālā, kuri atrodas konstantā magnētiskā laukā. Pēc iepazīšanās ar kvantu mehānikas matemātisko struktūru un galvenajām atvērto sistēmu modelēšanas metodēm, tiek veikti skaitliski aprēķini, kuri ļauj iegūt optiski detektētās magnētiskās rezonanses spektrus un krāsu centru elektronu un kodolu spinu polarizācijas raksturīgos lielumus. Iegūtie rezultāti tiek salīdzināti ar literatūrā pieejamajiem eksperimentālajiem datiem.
PROPOSAL FOR A LANDSCAPE EVALUATION SYSTEM
2023
Abstract. This paper describes a system, currently being designed, for both perceptual analysis and aesthetic evaluation of a landscape. The choice of this topic is motivated by the fact that systems related to landscape visibility (e.g. Geographical Information Systems (GIS) for visual impact assessment) are not fully satisfactory when it comes to assessing the aesthetic appearance. They mainly analyse geometric aspects, such as the width of visual basins or the interference of visual trajectories, which can be expressed by objective and comparable parameters. Instead, for effective landscape knowledge and protection, it is important to consider other factors that cannot be easily measured…
Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy
2015
The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the GdIII-DOTA (DOTA = tetraazacyclododecanetetraacetic acid) complex has been observed experimentally. Its line width is essentially unaffected by paramagnetic relaxation due to gadolinium, and is only affected by the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constants) calculated by relativistic DFT methods. This finding opens up new avenues for investigating the structure and reactivity of paramagnetic GdIII complexes used as contrast agents in magnetic resonance imaging.
Magnetic Resonance Imaging-Guided Focused Ultrasound Surgery for the Treatment of Symptomatic Uterine Fibroids
2017
Uterine fibroids, the most common benign tumor in women of childbearing age, may cause symptoms including pelvic pain, menorrhagia, dysmenorrhea, pressure, urinary symptoms, and infertility. Various approaches are available to treat symptomatic uterine fibroids. Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) represents a recently introduced noninvasive safe and effective technique that can be performed without general anesthesia, in an outpatient setting. We review the principles of MRgFUS, describing patient selection criteria for the treatments performed at our center and we present a series of five selected patients with symptomatic uterine fibroids treated with this not y…
Malignancy course of pituitary adenoma in MEN1 syndrome: Clinical-Neuroradiological signs
2020
Pituitary carcinomas (PCa) are extremely rare, indistinguishable from pituitary adenomas on histopathological grounds and have a poor prognosis. Most PCa start as PRL or ACTH secreting tumors in males, with relapsing invasive behaviour, refractoriness to medical and radiotherapy and increasing hormonal levels. The presence of distant metastases is still required for the diagnosis of PCa. The association with genetic endocrine diseases must be taken into account, since it adds further risk of evolution towards malignancy. Intradural spinal metastases have also been reported, so a complete craniospinal MR evaluation is recommended, when clinically indicated. We report a case of PCa, associate…
CT and MR imaging of cystic renal lesions
2020
AbstractCystic renal lesions are a common incidental finding on routinely imaging examinations. Although a benign simple cyst is usually easy to recognize, the same is not true for complex and multifocal cystic renal lesions, whose differential diagnosis includes both neoplastic and non-neoplastic conditions. In this review, we will show a series of cases in order to provide tips to identify benign cysts and differentiate them from malignant ones.
Rohkem kui sõnad
2007
Artikkel julgustab rakenduslingviste lisama verbaalse keele uurimise paradigmasse visuaalse keele mudelid ja teooriad, kaasama visuaalset kompetentsi, visuaalse kirjaoskuse ja ladususe kusimusi diskussiooni lingvistilise kompetentsi, kirjaoskuse, ladususe jms ule. Kommunikatsiooni visuaalseid elemente kohtab koige enam reklaamikontekstis. Arvatakse, et reklaamide visuaalsed kujutised (visuaalid) parandavad suhtumist brandi ning mojutavad positiivselt kaitumiskavatsusi. Artiklis kasitletakse visuaalide moningaid aspekte keele ja kommunikatsiooni vaatenurgast ning antakse luhiulevaade neurookonoomika neist tulemustest, mis on saadud magnetresonantsuuringute ( Magnetic Resonance Imaging ehk MR…
Kinetics of photochemical isomerization of TFA-Gly-ZΔPhe into TFA-Gly-EΔPhe
2017
The kinetics of photoisomerization of trifluoroacetyl-(Z)-dehydrophenylalanylglycine into trifluoroacetyl-(E)- dehydrophenylalanylglycine was studied in the hope that light-induced reaction could be useful as a means of preparation of the E-dehydropeptides. The obtained results indicate that if this reaction carried out under irradiation with light of wavelength 360 nm it is practically irreversible and gave nearly quantitatively pure Eisomer Significantly, expected cyclic side-products were not observed in the reaction mixture, thus proving the preparative potential of the elaborated procedure.
Cytoplasmic 5′-3′ exonuclease Xrn1p is also a genome-wide transcription factor in yeast
2014
The 5′ to 3′ exoribonuclease Xrn1 is a large protein involved in cytoplasmatic mRNA degradation as a critical component of the major decaysome. Its deletion in the yeast Saccharomyces cerevisiae is not lethal, but it has multiple physiological effects. In a previous study, our group showed that deletion of all tested components of the yeast major decaysome, including XRN1, results in a decrease in the synthetic rate and an increase in half-life of most mRNAs in a compensatory manner. Furthermore, the same study showed that the all tested decaysome components are also nuclear proteins that bind to the 5′ region of a number of genes. In the present work, we show that disruption of Xrn1 activi…
Motor Cortex Function in Fibromyalgia: A Study by Functional Near-Infrared Spectroscopy
2019
Previous studies indicated changes of motor cortex excitability in fibromyalgia (FM) patients and the positive results of transcranial stimulation techniques. The present study aimed to explore the metabolism of motor cortex in FM patients, in resting state and during slow and fast finger tapping, using functional Near-Infrared Spectroscopy (fNIRS), an optical method which detects in real time the metabolism changes in the cortical tissue. We studied 24 FM patients and 24 healthy subjects. We found a significant slowness of motor speed in FM patients compared to controls. During resting state and slow movement conditions, the metabolism of the motor areas was similar between groups. The oxy…