Search results for " SPECT"

Long-lived Humans Have a Unique Plasma Sphingolipidome

2021

A species-specific lipidome profile is an inherent feature linked to longevity in the animal kingdom. However, there is a lack of lipidomic studies on human longevity. Here, we use mass spectrometry-based lipidomics to detect and quantify 151 sphingolipid molecular species and use these to define a phenotype of healthy humans with exceptional life span. Our results demonstrate that this profile specifically comprises a higher content of complex glycosphingolipids (hexosylceramides and gangliosides), and lower levels of ceramide species from the de novo pathway, sphingomyelin and sulfatide; while for ceramide-derived signaling compounds, their content remains unchanged. Our findings suggest …

Surfactant self-assembling in gas phase: electrospray ionization- and matrix-assisted laser desorption/ionization-mass spectrometry of singly charged…

2005

The self-assembling of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in gas phase has been investigated by electrospray ionization- and matrix-assisted laser desorption/ionization mass spectrometry. Large surfactant clusters with an aggregation number close to that found in apolar media have been observed either as positive or negative ions. Moreover, the marked predominance of singly charged species as well as preliminary theoretical calculations strongly suggest an aggregate structure characterized by an internal hydrophilic core hosting the extra charge surrounded by an apolar shell constituted by the surfactant alkyl chains. This structure is similar to that of the more familiar revers…

Lysozyme Aggregation Driven by Unfolding: the Role of Metal Ions

2007

2020

Motor control is associated with suppression of oscillatory activity in alpha (8–12 Hz) and beta (12–30 Hz) ranges and elevation of oxygenated hemoglobin levels in motor-cortical areas. Aging leads to changes in oscillatory and hemodynamic brain activity and impairments in motor control. However, the relationship between age-related changes in motor control and brain activity is not yet fully understood. Therefore, this study aimed to investigate age-related and task-complexity-related changes in grip force control and the underlying oscillatory and hemodynamic activity. Sixteen younger [age (mean ± SD) = 25.4 ± 1.9, 20–30 years] and 16 older (age = 56.7 ± 4.7, 50–70 years) healthy men were…

Histaminanaloge, 27. Mitt. Bis (2,2′-histamine)

1985

Es wurden p-Phenylen-bis(2,2′-histamin) (6a), Ethylen-bis(2,2′-histamin) (6b), Tetramethylen-bis(2,2′-histamin) (6c) und Hexamethylen-bis(2,2′-histamin) (6d) dargestellt und auf Histamin-H1-und H2-agonistische Aktivitat untersucht. Histamine Analogues, XXVII: Bis(2,2′-histamines) p-Phenylenebis(2,2′-histamine) (6a), ethylenebis(2,2′-histamine) (6b), tetramethylenebis(2,2′-histamine) (6c), and hexamethylenebis(2,2′-histamine) (6d) were prepared and tested for histamine H1,-and H2-agonistic activity.

2021

The cell—cell signaling gene CDH13 is associated with a wide spectrum of neuropsychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), autism, and major depression. CDH13 regulates axonal outgrowth and synapse formation, substantiating its relevance for neurodevelopmental processes. Several studies support the influence of CDH13 on personality traits, behavior, and executive functions. However, evidence for functional effects of common gene variation in the CDH13 gene in humans is sparse. Therefore, we tested for association of a functional intronic CDH13 SNP rs2199430 with ADHD in a sample of 998 adult patients and 884 healthy controls. The Big Five personality tra…

Combined target and post-run target strategy for a comprehensive analysis of pesticides in ambient air using liquid chromatography-Orbitrap high reso…

2014

Abstract A comprehensive strategy for the analysis of current airborne pesticides has been developed using liquid chromatography coupled to high resolution mass spectrometry. The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous statistical optimisation of the main factors governing the ion source ionization and a study of the single-stage Orbitrap fragmentation through the HCD cell. The quantitative method presented recoveries ranging from 73 to 116%, with precision (RSD) lower than 20%, for the 35 substances in the scope of the target method. The full-scan accurate mass data were acquired w…

Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.

2005

Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur conte…

Anodizing and post-anodizing processes to enhance corrosion resistance of Al alloys

2021

In this work the dependence of corrosion resistance of Al alloys AA 2024-T3 on sealing treatments was studied. AA 2024-T3 samples were anodized at 14 V in a bath containing sulfuric and tartaric acids. Anodized samples were sealed with four different treatments: hot water, vapour, hot water with salts and stirred hot water. Electrochemical Impedance Spectroscopy measurements were performed to estimate samples' corrosion resistance in a solution simulating sea water environment. Samples sealed in hot water showed the highest corrosion resistance.

The first sorbicillinoid alkaloids, the antileukemic sorbicillactones A and B, from a sponge-derived Penicillium chrysogenum strain

2005

The saltwater culture of a Penicillium chrysogenum strain isolated from the Mediterranean sponge Ircinia fasciculata yielded three new sorbicillin-derived compounds (1-3), whose structures were elucidated mainly by 2D NMR and mass spectrometry. Among them, sorbicillactones A (1) and B (2) are the first sorbicillinoid natural products that contain nitrogen. Compound 1 is anti-HIV active and it exhibits a strong cytotoxic activity against L5178y leukemic cells, combined with a relatively low toxicity to cervical carcinoma HeLa S3 cells and pheochromocytoma PC 12 cells. The absolute configurations of I and 2 were elucidated by quantum chemical calculation of circular dichroism (CD) spectra. An…