Search results for "MASS SPECTROMETRY"
showing 10 items of 2544 documents
Circulating irisin detection: Does it really work?
2015
The recent discovery of irisin has generated considerable interest in the scientific community. However, many studies on the biochemistry and biology of this intriguing hormone yielded controversial results in humans, which were mostly attributable to a number of drawbacks in the methods used for its detection and measurement.
Enantioselective determination of plasma protein binding of common amphetamine-type stimulants.
2021
Amphetamine-type stimulants (ATS) like amphetamine ('speed'), methamphetamine ('crystal meth') and 3,4-methylenedioxy-N-methylamphetamine (MDMA, 'ecstasy') represent some of the most frequently abused drugs worldwide. Another less frequently abused ATS is 4-fluoroamphetamine (4-FA). The enantiomers of these four compounds exhibit different pharmacokinetic and pharmacodynamic properties. According to the free drug theory, the pharmacological properties of a substance are dependent on its plasma protein binding (PPB). However, data on PPB of stimulant enantiomers in humans are rare or non-existent. Human plasma samples were spiked with racemic mixtures of the stimulants and subjected to ultra…
Characterization of the synthetic cannabinoid MDMB-CHMCZCA
2016
The synthetic cannabinoid MDMB-CHMCZCA was characterized by various spectroscopic techniques including NMR spectroscopy and tandem mass spectrometry. The synthetic sample was found to be of S-configuration by VCD spectroscopy and comparison of the data with DFT calculations, while ECD spectroscopy was found to be inconclusive in this case. The enantiomeric purity of samples from test purchases and police seizures was assessed by a self-developed chiral HPLC method.
CHARACTERIZATION AND ENERGETIC METABOLISM ANALYSIS OF DIFFERENT POPULATIONS OF UMBILICAL CORD MESENCHYMAL STEM CELLS FOR THE TREATMENT OF STROKE
Stroke is a leading cause of death and disability worldwide. A direct consequence of oxygen and glucose deprivation during stroke is the dysfunction of mitochondria that impairs oxidative metabolism and contributes to oxidative stress, neuronal death and inflammation. Human umbilical cord (UC)-derived MSCs (UC-MSCs) are an attractive source for regenerative medicine purposes due to their self-renewal and multipotent differentiation potential, immunomodulatory and anti-inflammatory abilities. Notably, because UC is supplied from only three blood vessels, the UC-MSCs are physiologically adapted to survive in a relatively hypoxic and glucose poor environment leading to the hypothesis that thes…
Reuse of Food Waste: The Chemical Composition and Health Properties of Pomelo (Citrus maxima) Cultivar Essential Oils
2022
The aim of the present study is to investigate the chemical profile, antioxidant activity, carbohydrate-hydrolysing enzyme inhibition, and hypolipidemic effect of essential oils (EOs) extracted from Sicilian Citrus maxima (pomelo) flavedo. Using gas-chromatography-mass spectrometry analysis (GC-MS) we analysed the Eos of five cultivars of C. maxima, namely, ‘Chadock’, ‘Maxima’, ‘Pyriformis’, ‘Terracciani’, and ‘Todarii’, and their blends. The antioxidant activity was performed by using a multi-target approach using 2,2′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reduc…
Indirect chronology method employing rare earth elements to identify Sagunto Castle mortar construction periods
2017
A novel indirect chronology method has been developed to identify Sagunto Castle construction periods. The method is based on the use of inductively coupled plasma mass spectrometry (ICP-MS) to determine rare earth elements (REE) and other trace elements in mortars. Additionally, a no destructive geochemical analysis based on X-ray fluorescence (XRF) was employed for major elements determination. Collected chemical data were processed through Principal Component Analysis (PCA) to highlight any differences among the mortars belonging to different buildings and construction periods. The results show that PCA analysis permits to discriminate construction periods according to mortar sample REE …
High-precision measurement of the mass difference between 102Pd and 102Ru
2019
The Q-value for the neutrinoless double electron capture on 102Pd, Qϵϵ(102Pd), is determined as the atomic mass difference between 102Pd and 102Ru. A precise measurement of the Qϵϵ(102Pd) at the SHIPTRAP Penning trap showed a more than 10σ deviation to the adopted Atomic Mass Evaluation (AME) value. The reliability of the SHIPTRAP measurement was challenged because the AME value was based on numerous experiments including β and electron capture decays and very precise (n, γ) data, all agreeing with each other. To solve the discrepancy, the Qϵϵ(102Pd) has now been determined with the JYFLTRAP Penning trap at the IGISOL facility in the Accelerator Laboratory of the University of Jyväskylä. Th…
Identification and quantification of phosphatidylcholines containing very long chain polyunsaturated fatty acid (VLC-PUFA) in bovine and human retina…
2010
The retina is one of the vertebrate tissues with the highest content in polyunsaturated fatty acids (PUFA). A large proportion of the retinal glycerophospholipids, especially those found in photoreceptor membranes, are dipolyunsaturated molecular species. Among them, dipolyunsaturated phosphatidylcholine molecular species are known to contain very long chain polyunsaturated fatty acids (VLC-PUFA) from the n-3 and n-6 series and having 24 to 36 carbon atoms (C24 to C36) and four to six double bonds. Recent interest in the role of VLC-PUFA arose from the findings that a protein named ELOngation of Very Long chain fatty acids 4 (ELOVL4) is involved in their biosynthesis and that mutations in E…
Mass measurements of As, Se, and Br nuclei, and their implication on the proton-neutron interaction strength toward the N=Z line
2021
Mass measurements of the $^{69}$As, $^{70,71}$Se and $^{71}$Br isotopes, produced via fragmentation of a $^{124}$Xe primary beam at the FRS at GSI, have been performed with the multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) of the FRS Ion Catcher with an unprecedented mass resolving power of almost 1,000,000. For the $^{69}$As isotope, this is the first direct mass measurement. A mass uncertainty of 22 keV was achieved with only 10 events. For the $^{70}$Se isotope, a mass uncertainty of 2.6 keV was obtained, corresponding to a relative accuracy of $\delta$m/m = 4.0$\times 10^{-8}$, with less than 500 events. The masses of the $^{71}$Se and $^{71}$Br isotopes were measured…
Recent experiments at the JYFLTRAP Penning trap
2020
AbstractThe JYFLTRAP double Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility offers excellent possibilities for high-precision mass measurements of radioactive ions. Around 400 atomic masses, including around 50 isomeric states, have been measured since JYFLTRAP became operational. JYFLTRAP has also been used as a high-resolution mass separator for decay spectroscopy experiments as well as an ion counter for fission yield studies. In this contribution, an overview of recent activities at the JYFLTRAP Penning trap is given, with a focus on nuclei discussed in the PLATAN2019 meeting.