111 research outputs found
The effects of memantine on prepulse inhibition.
Reduced prepulse inhibition (PPI) of startle provides evidence of deficient sensorimotor gating in several disorders, including schizophrenia. The role of NMDA neurotransmission in the regulation of PPI is unclear, due to cross-species differences in the effects of NMDA antagonists on PPI. Recent reports suggest that drug effects on PPI differ in subgroups of normal humans that differ in the levels of baseline PPI or specific personality domains; here, we tested the effects of these variables on the sensitivity of PPI to the NMDA antagonist, memantine. PPI was measured in male Sprague-Dawley rats, after treatment with memantine (0, 10 or 20 mg/kg, s.c.). Baseline PPI was then measured in 37 healthy adult men. Next, subjects were tested twice, in a double-blind crossover design, comparing either (1) placebo vs 20 mg of the NMDA antagonist memantine (n=19) or (2) placebo vs 30 mg memantine (n=18). Tests included measures of acoustic startle amplitude, PPI, autonomic indices and subjective self-rating scales. Memantine had dose- and interval-dependent effects on PPI in rats. Compared with vehicle, 10 mg/kg increased short-interval (10-20 ms) PPI, and 20 mg/kg decreased long-interval (120 ms) PPI. In humans, memantine caused dose-dependent effects on psychological and somatic measures: 20 mg was associated with increased ratings of happiness, and 30 mg was associated with increased ratings of dizziness. PPI at the 120 ms prepulse interval was increased by 20 mg, but not 30 mg of memantine. Subgroups most sensitive to the PPI-enhancing effects of memantine were those with low baseline PPI, or with personality scale scores suggestive of high novelty seeking, high sensation seeking, or high disinhibition. NMDA blockade with memantine appears to have dose- and interval-dependent effects on sensorimotor gating in rats and humans, particularly among specific subgroups of normal human subjects. These findings are discussed as they relate to consistencies across other studies in humans, as well as apparent inconsistencies in the NMDA regulation of PPI across species
Optimization of a high work function solution processed vanadium oxide hole-extracting layer for small molecule and polymer organic photovoltaic cells
We report a method of fabricating a high work function, solution processable vanadium oxide (V2Ox(sol)) hole-extracting layer. The atmospheric processing conditions of film preparation have a critical influence on the electronic structure and stoichiometry of the V2Ox(sol), with a direct impact on organic photovoltaic (OPV) cell performance. Combined Kelvin probe (KP) and ultraviolet photoemission spectroscopy (UPS) measurements reveal a high work function, n-type character for the thin films, analogous to previously reported thermally evaporated transition metal oxides. Additional states within the band gap of V2Ox(sol) are observed in the UPS spectra and are demonstrated using X-ray photoelectron spectroscopy (XPS) to be due to the substoichiometric nature of V2Ox(sol). The optimized V2Ox(sol) layer performance is compared directly to bare indium–tin oxide (ITO), poly(ethyleneoxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and thermally evaporated molybdenum oxide (MoOx) interfaces in both small molecule/fullerene and polymer/fullerene structures. OPV cells incorporating V2Ox(sol) are reported to achieve favorable initial cell performance and cell stability attributes
Tungsten Oxide Nanorods Array and Nanobundle Prepared by Using Chemical Vapor Deposition Technique
Tungsten oxide (WO3) nanorods array prepared using chemical vapor deposition techniques was studied. The influence of oxygen gas concentration on the nanoscale tungsten oxide structure was observed; it was responsible for the stoichiometric and morphology variation from nanoscale particle to nanorods array. Experimental results also indicated that the deposition temperature was highly related to the morphology; the chemical structure, however, was stable. The evolution of the crystalline structure and surface morphology was analyzed by scanning electron microscopy, Raman spectra and X-ray diffraction approaches. The stoichiometric variation was indicated by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy
Effect of apomorphine on cognitive performance and sensorimotor gating in humans
Contains fulltext :
88792.pdf (publisher's version ) (Closed access)INTRODUCTION: Dysfunction of brain dopamine systems is involved in various neuropsychiatric disorders. Challenge studies with dopamine receptor agonists have been performed to assess dopamine receptor functioning, classically using the release of growth hormone (GH) from the hindbrain as primary outcome measure. The objective of the current study was to assess dopamine receptor functioning at the forebrain level. METHODS: Fifteen healthy male volunteers received apomorphine sublingually (2 mg), subcutaneously (0.005 mg/kg), and placebo in a balanced, double-blind, cross-over design. Outcome measures were plasma GH levels, performance on an AX continuous performance test, and prepulse inhibition of the acoustic startle. The relation between central outcome measures and apomorphine levels observed in plasma and calculated in the brain was modeled using a two-compartmental pharmacokinetic-pharmacodynamic analysis. RESULTS: After administration of apomorphine, plasma GH increased and performance on the AX continuous performance test deteriorated, particularly in participants with low baseline performance. Apomorphine disrupted prepulse inhibition (PPI) on high-intensity (85 dB) prepulse trials and improved PPI on low intensity (75 dB) prepulse trials, particularly in participants with low baseline PPI. High cognitive performance at baseline was associated with reduced baseline sensorimotor gating. Neurophysiological measures correlated best with calculated brain apomorphine levels after subcutaneous administration. CONCLUSION: The apomorphine challenge test appears a useful tool to assess dopamine receptor functioning at the forebrain level. Modulation of the effect of apomorphine by baseline performance levels may be explained by an inverted U-shape relation between prefrontal dopamine functioning and cognitive performance, and mesolimbic dopamine functioning and sensorimotor gating. Future apomorphine challenge tests preferentially use multiple outcome measures, after subcutaneous administration of apomorphine.1 januari 201
Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium
Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio
Educar para los nuevos Medios. Claves para el desarrollo de la competencia mediática en el entorno digital
Educar es una de las labores más complejas, intensas y, a la vez, más maravillosas que puede acometer una persona. Ser docente es una tarea ilusionante. En un mundo en el que la información es cada vez más importante por la rapidez con que se produce y consume, la variedad de recursos con que se difunde constituye un reto en el papel de los educadores y educadoras. La educación para la comunicación, a través de los nuevos medios, requiere de habilidades y estrategias específicas e implica prácticas innovadoras. Este texto ofrece claves para desarrollar la competencia mediática necesaria para entender, usar y comunicar en el entorno digital. Desde el concepto de competencia mediática y la escuela prosumidora se muestran experiencias y planteamientos en distintos niveles educativos y contextos curriculares que ofrecen pistas para educar a la ciudadanía. Esta alfabetización aúna la perspectiva de la experiencia de docente receptor y consumidor, atendiendo a la recepción crítica de la información, la selección y administración de la misma, el reconocimiento de valores e ideologías y la gestión emocional, junto a la elaboración y creación de contenidos
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