Search results for "MAGNETIC RESONANCE"
showing 10 items of 4721 documents
Synthesis, Stability and Relaxivity of TEEPO-Met: An Organic Radical as a Potential Tumour Targeting Contrast Agent for Magnetic Resonance Imaging
2018
Cancer is a widespread and life-threatening disease and its early-stage diagnosis is vital. One of the most effective, non-invasive tools in medical diagnostics is magnetic resonance imaging (MRI) with the aid of contrast agents. Contrast agents that are currently in clinical use contain metals, causing some restrictions in their use. Also, these contrast agents are mainly non-specific without any tissue targeting capabilities. Subsequently, the interest has notably increased in the research of organic, metal-free contrast agents. This study presents a new, stable organic radical, TEEPO-Met, where a radical moiety 2,2,6,6-tetraethylpiperidinoxide (TEEPO) is attached to an amino acid, methio…
First synthesis of single-“strapped cyclam-porphyrins”
1994
The first synthesis of strapped cyclam porphyrins is described ; these will be studied as dioxygen carriers as well as cytochrome C oxidase models. The original derivatives are characterized by mass spectrometry and 1H NMR spectroscopy. The cofacial conformation of the two different macrocycles is confirmed by 1H NMR data.
Synthesis, characterization, and cytotoxic activity of copper(II) and platinum(II) complexes of 2-benzoylpyrrole and X-ray structure of bis[2-benzoyl…
2004
Copper(II) and platinum(II) complexes of 2-benzoylpyrrole (2-BZPH) were synthesized and characterized with IR, 1 H and 1 3 C NMR spectroscopies and coordination geometry with ligands arranged in transoid fashion. The crystal structure of [Cu I I (2-BZP) 2 ] was determined by X-ray diffraction. Death of complex treated Jurkat cells was measured by flow cytometry. The bis-chelate complexes [Cu I I (2-BZP) 2 ] and [Pt I I (2-BZP) 2 ] adopt square-planar coordination geometry with ligands, arranged in transoid fashion. Concentrations of 1-10 μM Platinum(II) complexes reduced cell survival from 100% to 20%, in contrast to the copper(II) complex which caused no cell death at a concentration of 10…
Concept of Spectrobiopsy Facing Gliomas: Rational and Future Perspectives Related to Target Therapy
2020
Gliomas represent the most common primary intracranial tumors with an estimated incidence of 31% of all central nervous system neoplasms. Lesions originated from glial cells are extremely heterogeneous, ranging from low grade to high grade with different clinical and biological malignancy. Glioblastoma multiforme (GBM) is the most aggressive and frequent primary malignant tumor of the central nervous system in adults. Even though in the past decades considerable efforts have been made in the therapeutic management of this type of tumor,2 the prognosis after diagnosis of GBM remains extremely poor, reaching a median overall survival of 12–18 months. In 2016 the World Health Organization clas…
Magnetic Resonance Spectrobiopsy for Prediction of Isocitrate Dehydrogenase Mutation in Glioma
2020
Despite the existence of multimodal therapy paradigm, high-grade gliomas (HGGs) remain devastating tumors associated with one of the worst prognoses. Glioblastoma (GBM) is the most frequent reported histologic type with a median survival, after surgery and combined treatment with chemotherapy and radiotherapy, ranging from 12 to 16 months. The poor prognosis is due to the lack of therapeutic efficacy of chemical agents and irradiation in hypoxic tumor areas. Experimental studies have investigated several molecules with the aim to counteract several downstream signaling important in tumor progression, unfortunately without conclusive results. Several studies have shown that the extent of res…
Design and implementation of PET detectors based on monolithic crystals and SiPMs
2018
Esta tesis doctoral se centra tanto en el diseño como en la validación experimental de detectores de rayos gamma para escáneres de tomografía por emisión de positrones (PET, del inglés Positron Emission Tomography). El objetivo principal de esta tesis es el diseño de innovadores bloques detectores PET de alto rendimiento. La técnica PET constituye una de las principales herramientas diagnósticas en medicina nuclear, que es una especialidad médica que utiliza sustancias radiactivas con fines diagnósticos y terapéuticos. Esta técnica de imagen médica permite visualizar procesos fisiológicos y bioquímicos del cuerpo humano in vivo, mediante la administración del elemento radiotrazador. Los rad…
Meta-analysis of real-time fMRI neurofeedback studies using individual participant data: How is brain regulation mediated?
2015
An increasing number of studies using real-time fMRI neurofeedback have demonstrated that successful regulation of neural activity is possible in various brain regions. Since these studies focused on the regulated region(s), little is known about the target-independent mechanisms associated with neurofeedback-guided control of brain activation, i.e. the regulating network. While the specificity of the activation during self-regulation is an important factor, no study has effectively determined the network involved in self-regulation in general. In an effort to detect regions that are responsible for the act of brain regulation, we performed a post-hoc analysis of data involving different ta…
Synthesis of Rosmarinic Acid Amides as Antioxidative and Hypoglycemic Agents
2019
Type 2 diabetes mellitus (T2DM) is an important metabolic disorder for which there is an urgent need for new antidiabetic drugs. α-Glucosidase inhibition is an established protocol for T2DM therapy. Because hyperglycemia causes oxidative tissue damage, the development of agents with both α-glucosidase inhibition and antioxidant activity from natural or natural-derived polyphenols such derivatives of rosmarinic acid (RA) represents an attractive therapeutic option. We report a study on amides 1-10 derived from RA and their evaluation for yeast α-glucosidase inhibition and antioxidant activity (DPPH and ORAC tests). All amides showed higher inhibitory activity than that of RA, were by far mor…
Mossbauer spectroscopic study of the thermal spin crossover in [Fe(II)(isoxazole)(6)](ClO(4))(2)
2008
The (57)Fe Mossbauer spectroscopy of mononuclear [Fe(II)(isoxazole)(6)](ClO(4))(2) has been studied to reveal the thermal spin crossover of Fe(II) between low-spin (S = 0) and high-spin (S = 2) states.Temperature-dependent spin transition curves have been constructed with the least-square fitted data obtained from the Mossbauer spectra measured at various temperatures between 84 and 270 K during a cooling and heating cycle. This compound exhibits an unusual temperature-dependent spin transition behaviour with T(C)(down arrow) = 223 and T(C)(up arrow) = 213 K occurring in the reverse order in comparison to those observed in SQUID observation and many other spin transition compounds. The comp…
Towards large‐scale steady‐state enhanced nuclear magnetization with in situ detection
2021
Magnetic resonance in chemistry 59(12), 1208 - 1215 (2021). doi:10.1002/mrc.5161