1,288 research outputs found
First Valence, Then Arousal: The Temporal Dynamics of Brain Electric Activity Evoked by Emotional Stimuli
The temporal dynamics of the neural activity that implements the dimensions valence and arousal during processing of emotional stimuli were studied in two multi-channel ERP experiments that used visually presented emotional words (experiment1) and emotional pictures (experiment2) as stimulus material. Thirty-two healthy subjects participated (mean age 26.8±6.4years, 24 women). The stimuli in both experiments were selected on the basis of verbal reports in such a way that we were able to map the temporal dynamics of one dimension while controlling for the other one. Words (pictures) were centrally presented for 450 (600) ms with interstimulus intervals of 1,550 (1,400) ms. ERP microstate analysis of the entire epochs of stimulus presentations parsed the data into sequential steps of information processing. The results revealed that in several microstates of both experiments, processing of pleasant and unpleasant valence (experiment1, microstate #3: 118-162ms, #6: 218-238ms, #7: 238-266ms, #8: 266-294ms; experiment2, microstate #5: 142-178ms, #6: 178-226ms, #7: 226-246ms, #9: 262-302ms, #10: 302-330ms) as well as of low and high arousal (experiment1, microstate #8: 266-294ms, #9: 294-346ms; experiment2, microstate #10: 302-330ms, #15: 562-600ms) involved different neural assemblies. The results revealed also that in both experiments, information about valence was extracted before information about arousal. The last microstate of valence extraction was identical with the first microstate of arousal extractio
Substitution of critical raw materials in low-carbon technologies: lighting, wind turbines and electric vehicles
This report evaluates the substitution options of nine critical raw materials (CRM) (Eu, Tb, Y, In, Ga, Ge Nd, Pr and Dy) required in lighting, wind turbines and electric vehicles applications. Substitution has been considered from many perspectives from reducing the use of CRM via improved material efficiency to substitution at material and component level.
Despite of many years of research, a direct and complete replacement of the critical raw materials in phosphors, LEDs and permanent magnets by other more easily available and less critical is still not commercially available. However, substitution has the potential to reduce the future demand for CRM in low-carbon technologies sector through improving material efficiency and component substitution.
In lighting sector, markets have started shifting from fluorescent to light-emitting diode (LED) technology. This transition leads to declining the demand for terbium, europium, yttrium and germanium by 2020, though demand for gallium and indium tends to increase. In organic-LED (OLED) critical raw materials (with exception of indium) are substituted by organic compounds. It is expected that OLED technology will widely penetrate the general lighting market after 2025, thus further reducing the demand for phosphors and critical raw materials in lighting.
Due to concerns regarding rare earths supply, some wind manufacturers started to develop, adopt or switch to alternative turbine technologies which rely on less rare earth or none at all. In parallel, research made relevant progress on reducing the amount of heavy rare earths, such as dysprosium or terbium, in wind turbines. Currently, there is large pool of rare earths-free turbine designs of more than 5 MW that can satisfy the wind power market. The future market share of different turbine types will highly depend on the development of rare earths prices and technological advantages. For offshore applications, sector in which the EU is leader, the direct drive permanent magnet synchronous generator (DD-PMSG) containing rare earths demonstrated a series of advantages especially in terms of efficiency and lower maintenance. In order to keep its leadership and competitiveness in the wind offshore sector, the EU should continue investing in rare earth substitution among adoption of other measures to secure rare earths supply.
Currently, the permanent magnet synchronous traction motors (PSM) containing rare earths is the technology of choice for electric vehicles. Alternative rare earths-free electric motors (e.g. asynchronous or electrically excited synchronous machines) exist for battery electric vehicles (BEVs). The lack of component substitution for PSM in serial production of hybrid electric vehicles represents the major challenges because these models dominate today the EVs sector.JRC.C.7 - Knowledge for the Energy Unio
Robustness of the charge-ordered phases in against photoexcitation
We present a time-resolved angle-resolved photoelectron spectroscopy study of IrTe2, which undergoes two first-order structural and charge-ordered phase transitions on cooling below 270 K and below 180 K. The possibility of inducing a phase transition by photoexcitation with near-infrared femtosecond pulses is investigated in the charge-ordered phases. We observe changes of the spectral function occurring within a few hundreds of femtoseconds and persisting up to several picoseconds, which we interpret as a partial photoinduced phase transition (PIPT). The necessary time for photoinducing these spectral changes increases with increasing photoexcitation density and reaches time scales longer than the rise time of the transient electronic temperature. We conclude that the PIPT is driven by a transient increase of the lattice temperature following the energy transfer from the electrons. However, the photoinduced changes of the spectral function are small, which indicates that the low- temperature phase is particularly robust against photoexcitation. We suggest that the system might be trapped in an out-of-equilibrium state, for which only a partial structural transition is achieved
Cardiac outcomes in adults with supravalvar aortic stenosis
Aims Supravalvar aortic stenosis is a rare form of left ventricular outflow tract obstruction that is often progressive in childhood. Little data are available on outcomes in the adult population. Our aim was to define cardiac outcomes in adults with supravalvar aortic stenosis. Methods and results This is a multicentre retrospective study of cardiac outcomes in adults (≥18 years) with supravalvar aortic stenosis. We examined: (i) adverse cardiac events (cardiovascular death, myocardial infarction, stroke, heart failure, sustained arrhythmias, and infective endocarditis) and (ii) the need for cardiac surgery in adulthood. One hundred and thirteen adults (median age at first visit 19 years; 55% with Williams-Beuren syndrome; 67% with surgical repair in childhood) were identified. Adults without Williams-Beuren syndrome had more severe supravalvar aortic stenosis and more often associated left ventricular outflow tract obstructions (P < 0.001). In contrast, mitral valve regurgitation was more common in patients with Williams-Beuren syndrome. Eighty-five per cent of adults (96/113) had serial follow-up information (median follow-up 6.0 years). Of these patients, 13% (12/96) had an adverse cardiac event and 13% (12/96) had cardiac operations (7 valve repair or replacements, 4 supravalvar aortic stenosis repairs, 1 other). Cardiac surgery was more common in adults without Williams-Beuren syndrome (P = 0.007). Progression of supravalvar aortic stenosis during adulthood was rare. Conclusion Adults with supravalvar aortic stenosis remain at risk for cardiac complications and reoperations, while progression of supravalvar aortic stenosis in adulthood is rare. Valve surgery is the most common indication for cardiac surgery in adulthoo
Gender differences in myocardial salvage and clinical outcome in patients with acute reperfused ST-elevation myocardial infarction
Relationship and prognostic value of microvascular obstruction and infarct size in st-elevation myocardial infarction as visualized by magnetic resonance imaging
Impact of gender on the prevalence and extent of microvascular obstruction after st-elevation myocardial infarction
Intra- and Interobserver Variability of different CMR-ratios for the detection of myocardial inflammation in patients with suspected acute viral myocarditis
Technical Note: On Uncertainties in Plant Water Isotopic Composition Following Extraction by Cryogenic Vacuum Distillation
Recent studies have challenged the interpretation of plant water isotopes obtained through cryogenic vacuum distillation (CVD) based on observations of a large 2H fractionation. These studies have hypothesized the existence of an H-atom exchange between water and organic tissue during CVD extraction with the magnitude of H exchange related to relative water content of the sample; however, clear evidence is lacking. Here, we systematically tested the uncertainties in the isotopic composition of CVD-extracted water by conducting a series of incubation and rehydration experiments using isotopically depleted water, water at natural isotope abundance, woody materials with exchangeable H, and organic materials without exchangeable H (cellulose triacetate and caffeine). We show that the offsets between hydrogen and oxygen isotope ratios and expected reference values (Δ2H and Δ18O) have inversely proportional relationships with the absolute amount of water being extracted, i.e. the lower the water amount, the higher the Δ2H and Δ18O. However, neither Δ2H nor Δ18O values, were related to sample relative water content. The Δ2H pattern was more pronounced for materials with exchangeable H atoms than with non-exchangeable H atoms. This is caused by the combined effect of H exchange during the incubation of materials in water and isotopic enrichments during evaporation and sublimation that depend on absolute water amount. The H exchange during CVD extraction itself was negligible. Despite these technical issues, we observed that the water amount-dependent patterns were much less pronounced for samples at natural isotope abundance and particularly low when sufficiently high amounts of water were extracted (\u3e600 µL). Our study provides new insights into the mechanisms causing isotope fractionation during CVD extraction of water. The methodological uncertainties can be controlled if large samples of natural isotope abundance are used in ecohydrological studies
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