1,313 research outputs found
Measuring thermal expansion of multiple specimens at high temperature
Furnace capable of heating 10 specimens to a uniform temperature simultaneously, aids in the measuring of the thermal expansion of each specimen. The specimens are measured with a telescope unit consisting of two microtelescopes. Overall accuracy of the system is estimated to be plus or minus 2 percent at 2000 degrees C
Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping
We investigate coherent phonon propagation in a thin film of ferroelectric
PbZr0.2Ti0.8O3 (PZT) by ultrafast x-ray diffraction (UXRD) experiments, which
are analyzed as time-resolved reciprocal space mapping (RSM) in order to
observe the in- and out-of-plane structural dynamics simultaneously. The mosaic
structure of the PZT leads to a coupling of the excited out-of-plane expansion
to in-plane lattice dynamics on a picosecond timescale, which is not observed
for out-of-plane compression.Comment: 5 pages, 4 figure
Thermoelastic study of nanolayered structures using time-resolved x-ray diffraction at high repetition rate
We investigate the thermoelastic response of a nanolayered sample composed of
a metallic SrRuO3 (SRO) electrode sandwiched between a ferroelectric
Pb(Zr0.2Ti0.8)O3 (PZT) film with negative thermal expansion and a SrTiO3
substrate. SRO is rapidly heated by fs-laser pulses with 208 kHz repetition
rate. Diffraction of x-ray pulses derived from a synchrotron measures the
transient out-of-plane lattice constant c of all three materials simultaneously
from 120 ps to 5 mus with a relative accuracy up to Delta c/c = 10^-6. The
in-plane propagation of sound is essential for understanding the delayed out of
plane expansion.Comment: 5 pages, 3 figure
Localized excited charge carriers generate ultrafast inhomogeneous strain in the multiferroic BiFeO
We apply ultrafast X-ray diffraction with femtosecond temporal resolution to
monitor the lattice dynamics in a thin film of multiferroic BiFeO after
above-bandgap photoexcitation. The sound-velocity limited evolution of the
observed lattice strains indicates a quasi-instantaneous photoinduced stress
which decays on a nanosecond time scale. This stress exhibits an inhomogeneous
spatial profile evidenced by the broadening of the Bragg peak. These new data
require substantial modification of existing models of photogenerated stresses
in BiFeO: the relevant excited charge carriers must remain localized to be
consistent with the data
A Bleeding Kiss: intramural haematoma secondary to balloon angioplasty
<p>Abstract</p> <p>Background</p> <p>Intramural coronary haematoma following percutaneous coronary intervention in the absence of coronary dissection is a rare phenomenon.</p> <p>Case presentation</p> <p>A 69 year old lady with previous prosthetic aortic valve replacement underwent percutaneous coronary intervention (PCI) from the left mainstem to the left anterior descending artery (LAD) and kissing balloon inflations to the LAD and circumflex (Cx) arteries. Although intravascular ultrasound examination (IVUS) of both the LAD and Cx showed both vessels to be widely patent at the end of the procedure, she developed ischaemic chest pain six hours later. Repeat coronary angiography revealed a significant stenosis in the proximal Cx vessel, which was confirmed on IVUS to be intramural haematoma.</p> <p>Conclusion</p> <p>In patients taking warfarin in addition to standard antiplatelet therapy, kissing balloon inflations should be carried out with caution.</p
The role of consciousness in cognitive control and decision making
Here we review studies on the complexity and strength of unconscious information processing. We focus on empirical evidence that relates awareness of information to cognitive control processes (e.g., response inhibition, conflict resolution, and task-switching), the life-time of information maintenance (e.g., working memory) and the possibility to integrate multiple pieces of information across space and time. Overall, the results that we review paint a picture of local and specific effects of unconscious information on various (high-level) brain regions, including areas in the prefrontal cortex. Although this neural activation does not elicit any conscious experience, it is functional and capable of influencing many perceptual, cognitive (control) and decision-related processes, sometimes even for relatively long periods of time. However, recent evidence also points out interesting dissociations between conscious and unconscious information processing when it comes to the duration, flexibility and the strategic use of that information for complex operations and decision-making. Based on the available evidence, we conclude that the role of task-relevance of subliminal information and meta-cognitive factors in unconscious cognition need more attention in future work
Rimonabant improves cardiometabolic risk factors in overweight/obese patients with poorly controlled type 2 diabetes (HbA(1c)>= 8%) on monotherapy with metformin or sulfonylureas
peer reviewe
Rimonabant improves multiple cardiometabolic risk factors in diabetic and non-diabetic overweight/obese patients: data from RIO-diabetes, RIO-Europe, RIO-North America and RIO-Lipids
Exploring the role of expectations and stimulus relevance on stimulus-specific neural representations and conscious report
Manipulating word awareness dissociates feed-forward from feedback models of language-perception interactions
Previous studies suggest that linguistic material can modulate visual perception, but it is unclear at which level of processing these interactions occur. Here we aim to dissociate between two competing models of language–perception interactions: a feed-forward and a feedback model. We capitalized on the fact that the models make different predictions on the role of feedback. We presented unmasked (aware) or masked (unaware) words implying motion (e.g. “rise,” “fall”), directly preceding an upward or downward visual motion stimulus. Crucially, masking leaves intact feed-forward information processing from low- to high-level regions, whereas it abolishes subsequent feedback. Under this condition, participants remained faster and more accurate when the direction implied by the motion word was congruent with the direction of the visual motion stimulus. This suggests that language–perception interactions are driven by the feed-forward convergence of linguistic and perceptual information at higher-level conceptual and decision stages
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