Search results for "wave"
showing 10 items of 6009 documents
Angiographic co-registration of instantaneous wave-free ratio and intravascular ultrasound improves functional assessment of borderline lesions in th…
2018
P-Wave Indices: Derivation of Reference Values from the Framingham Heart Study
2010
P wave indices constitute an intermediate, phenotype reflecting the impact of ischemic, metabolic and inflammatory insults on atrial electrophysiology and morphology. Measured from the surface electrocardiogram (ECG), they reflect dimensions of atrial depolarization and are modified by conditions that alter atrial conduction, atrial refractoriness, or may result in a proarrhythmic substrate. The P wave indices of duration and dispersion have most commonly been measured. An array of studies have utilized these P wave indices to distinguish subjects with diverse cardiovascular and non-cardiovascular conditions and diseases from healthy reference groups.(1) Computerized software has more recen…
Cardiac Autonomic Activity during Sleep under the Influence of Radiofrequency Electromagnetic Fields. Autonome Herzaktivitat im Schlaf unter dem Einf…
2005
Question of the study We investigated the influence of radiofrequency electromagnetic fields emitted by digital mobile telephones on heart rate variability (HRV) during sleep in healthy young men.
Computertomographie nach extrakorporaler Stoßwellenlithotripsie (ESWL) der Nieren
1993
In 105 patients CT studies were done prospectively after renal ESWL with a second generation lithotripter. 33 (31%) of the patients had renal oedema (n = 8), renal (n = 20) or extrarenal (n = 31) bleeding. Three of the 23 patients who had a three year follow-up had chronic renal changes, 10 had renal stones. As blunt renal trauma can be the cause of renal hypertension a longterm follow-up is necessary in ESWL patients, particularly if there was renal bleeding after treatment. Further studies are needed to determine the exact risk of renal hypertension after ESWL.
The sleep EEG's microstructure in depression: alterations of the phase relations between EEG rhythms during REM and NREM sleep
2002
Abstract Objective : We investigated the microstructure of sleep electroencephalograms (EEGs) of 13 unmedicated depressive inpatients and 13 healthy controls matched in sex and age, hypothesizing that depressives depict an alteration of certain EEG oscillations across the night. Methods : We digitized the sleep EEGs with a sampling rate of 100Hz (bipolar derivation C z –P z , 1440 single sweeps; 2048 data points each), calculated the time course of delta (1–3.5Hz), theta (3.5–7.5Hz), alpha (7.5–15Hz), and beta (15–35Hz) activity over the night, and determined the correlation coefficients of these different EEG rhythms separately for rapid eye movement (REM) and non-rapid eye movement (NREM)…
Terahertz polarization-division multiplexing within a four-wire waveguide
2022
We demonstrate a new metal-wire waveguide topology, namely a four-wire waveguide, which simultaneously acts as a broadband terahertz polarization-division multiplexer and as a novel platform to realize the independent manipulation of polarization-division multiplexed terahertz signals.
Détection des ruptures de fibres et du délaminage dans les composites verre/époxy et carbone/époxy à l'aide de structures propagatives dans la gamme …
2009
National audience; On présente dans cet article la détection de ruptures de fibre et du délaminage dans les composites unidirectionnels verre/époxy et carbone/époxy en utilisant des structures propagatives électromagnétiques dans la gamme des micro-ondes.
A microwave cylindrical cavity made of bulk MgB2 superconductor produced by reactive liquid Mg infiltration process
2007
Dielectric properties of myoglobin at 10 GHz by microwave cavity perturbation measurements
2010
We report on the temperature dependence, at microwave (mw) frequency, of the imaginary part of the dielectric constant (En) in myoglobin powder samples with different hydration levels (h). The measurements have been performed by the cavity perturbation technique, in the range of temperature 80-345 K. The sample is located inside a glass capillary along the axis of a cylindrical copper cavity, resonating in the TE011 mode at 9.6 GHz, where the mw electric field has a node. By measuring the variation of the quality factor of the resonant cavity, one can extract the imaginary part of the dielectric constant. At temperatures higher than 230 K we observe an evident increase of the dielectric los…
Microwave response of bulk MgB2 samples of different granularity
2006
The microwave response of three high-density bulk MgB2 samples has been investigated in the linear and nonlinear regimes. The three samples, characterized by different mean size of grains, have been obtained by reactive infiltration of liquid Mg in powdered B preforms. The linear response has been studied by measuring the microwave surface impedance; the nonlinear response by detecting the power radiated by the sample at the second-harmonic frequency of the driving field. Our results suggest that bulk MgB2 prepared by the liquid Mg infiltration technique is particularly promising for manufacturing resonant cavities operating at microwave frequencies.