Valle M.,Pharmacokinetic and Pharmacodynamic Modelling and Simulation |
Valle M.,Hospital Of La Santa Creu I Sant Pau |
Valle M.,Autonomous University of Barcelona |
Valle M.,Research Center Biomedica En Red Of Salud Mental |
And 23 more authors.
European Neuropsychopharmacology | Year: 2016
Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus β-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75 mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40 mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans. © 2016 Elsevier B.V. and ECNP.
Rabella M.,Hospital Of La Santa Creu I Sant Pau |
Rabella M.,Autonomous University of Barcelona |
Grasa E.,Hospital Of La Santa Creu I Sant Pau |
Grasa E.,Research Center Biomedica En Red Of Salud Mental |
And 18 more authors.
NeuroImage: Clinical | Year: 2016
Background Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits. Methods We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design. Results After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals. Conclusions These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists. © 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license.
Espriu-Gascon A.,Universitatpolitecnica Of Catalonia Upc |
Bastos-Arrieta J.,Universitatpolitecnica Of Catalonia Upc |
Gimenez J.,Universitatpolitecnica Of Catalonia Upc |
Casas I.,Universitatpolitecnica Of Catalonia Upc |
And 2 more authors.
International Journal of Nanotechnology | Year: 2016
To assess the safety of the deep geological disposal that would store the spent nuclear fuel (SNF), studies are centred on the SNF behaviour under repository conditions. UO2, which is the most common compound of SNF matrix, is highly sensitive to the redox potential and it could be oxidised to more soluble phases, enhancing the liberation of harmful radionuclides. Among fission products in the SNF, ε-particles (nanoparticles) are believed to play an important role avoiding the oxidation. Consequently, scientists are testing efficient and low cost methodologies for the preparation of novel materials by incorporation of nanoparticles into bulk components. In this communication we present the methodology for preparation of non-irradiated UO2 doped with Pd Nanoparticles (Pd-NPs), as an analogue of ε-particles present in the SNF. Pd-NPs doped UO2 samples were characterised by high resolution electron microscopy to identify the presence, the morphology and distribution of the nanoparticles. Copyright © 2016 Inderscience Enterprises Ltd.
Giden I.H.,TOBB University of Economics and Technology |
Kurt H.,TOBB University of Economics and Technology |
Turduev M.,TOBB University of Economics and Technology |
Staliunas K.,Universitatpolitecnica Of Catalonia Upc
2014 IEEE Photonics Conference, IPC 2014 | Year: 2014
Graded Index Photonic Crystals (GRIN PhCs) are artificial periodic materials that possess gradually varying effective refractive indices. GRIN profiles can be formed by adjusting the radii or the locations of PhC unit cells. GRIN PhCs exhibit several intriguing characteristics which can be listed as demultiplexing , mode-order conversion , asymmetric light propagation , compact lensing , and coupling between waveguides of different widths . In addition to pure GRIN effects, the effects arising from the combinations of PhC properties (photonic bandgaps) can even enrich the possibilities of light manipulations. As a result, broad band transmission spectrum is combined with the directional band gaps . Angular selectivity also can be utilized to separate different wavelengths . Lastly, point and line defects can be introduced to have cavity and waveguides with GRIN PhC. © 2014 IEEE.
Garcia-Benadi A.,Universitatpolitecnica Of Catalonia Upc |
Corredera P.,CSIC - Institute of Optics |
Del Campo Maldonado M.D.,Centro Espanol Of Metrologia |
Del-Rio-Fernandez J.,Universitatpolitecnica Of Catalonia Upc |
And 4 more authors.
XXI IMEKO World Congress "Measurement in Research and Industry" | Year: 2015
In the framework of the EMRP project "ENV 58. Metrology for essential climate variables", a new technique to perform traceable temperature measurements of the sea water profile and sea water surface will be studied, developed and applied to a real situation. This new thermometer consists on several Bragg gratings located at different points along an optical fiber, getting a thermometer based on distributed temperature sensors, that will be used to measure the sea water temperature profile. This technique will provide additional and valuable information about the evolution of the sea environment behaviour.
Garcia-Benadi A.,Universitatpolitecnica Of Catalonia Upc |
Molino-Minero-Re E.,Universitatpolitecnica Of Catalonia Upc |
Del Rio-Fernandez J.,Universitatpolitecnica Of Catalonia Upc |
Manuel-Lazaro A.,Universitatpolitecnica Of Catalonia Upc
International Journal of Metrology and Quality Engineering | Year: 2013
This paper describes the methodology of the compatibility criteria E n and the methodology of repeatability and reproducibility (R&R) throught the average and range method. With this paper we will use the methodology R&R for the evaluation of the compatibility criteria between the staff of the laboratories, where independent measurements are not insured. © 2013 EDP Sciences.