2,318 research outputs found
Fear of exercise and health-related quality of life in patients with an implantable cardioverter defibrillator
Several studies have reported improved survival rates thanks to the use of an implantable cardioverter defibrillator (ICD) in the treatment of patients with life-threatening arrhythmia. However, the effects of the ICD on health-related quality of life (HR-QoL) of these patients are not clear. The aim of this study is to describe HR-QoL and fear of exercise in ICD patients. Eighty-nine ICD patients from the University Hospital in Groningen, the Netherlands, participated in this study. HR-QoL was measured using the Rand-36 and the Quality of Life After Myocardial Infarction Dutch language version questionnaires. Fear of exercise was measured using the Tampa Scale for Kinesiophobia, Dutch version and the Fear Avoidance Beliefs Questionnaire, Dutch version. Association between outcome variables was analysed by linear regression analyses. Study results show that the HR-QoL of patients with ICDs in our study population is significantly worse than that of normal healthy people. Furthermore, fear of exercise is negatively associated with HR-QoL corrected for sex, age and number of years living with an ICD. After implantation of the ICD, patients with a clear fear of exercise should be identified and interventions should be considered in order to increase their HR-QoL
8x14Gb/s ring WDM modulator array with integrated tungsten heaters and Ge monitor photodetectors
An 8x14Gb/s wavelength-division multiplexed Si ring modulator array is presented with uniform channel performance. Tungsten heaters and Ge monitor photodetectors at the ring modulator drop ports are co-integrated to track and control the modulation quality
Mitochondrial encephalocardio-myopathy with early neonatal onset due to TMEM70 mutation
Objective Mitochondrial disturbances of energy-generating systems in childhood are a heterogeneous group of disorders. The aim of this multi-site survey was to characterise the natural course of a novel mitochondrial disease with ATP synthase deficiency and mutation in the TMEM70 gene.
Methods Retrospective clinical data and metabolic profiles were collected and evaluated in 25 patients (14 boys, 11 girls) from seven European countries with a c. 317-2A -> G mutation in the TMEM70 gene.
Results Severe muscular hypotonia (in 92% of newborns), apnoic spells (92%), hypertrophic cardiomyopathy (HCMP; 76%) and profound lactic acidosis (lactate 5-36 mmol/l; 92%) with hyperammonaemia (100-520 mu mol/l; 86%) were present from birth. Ten patients died within the first 6 weeks of life. Most patients surviving the neonatal period had persisting muscular hypotonia and developed psychomotor delay. HCMP was non-progressive and even disappeared in some children. Hypospadia was present in 54% of the boys and cryptorchidism in 67%. Increased excretion of lactate and 3-methylglutaconic acid (3-MGC) was observed in all patients. In four surviving patients, life-threatening hyperammonaemia occurred during childhood, triggered by acute gastroenteritis and prolonged fasting.
Conclusions ATP synthase deficiency with mutation in TMEM70 should be considered in the diagnosis and management of critically ill neonates with early neonatal onset of muscular hypotonia, HCMP and hypospadias in boys accompanied by lactic acidosis, hyperammonaemia and 3-MGC-uria. However, phenotype severity may vary significantly. The disease occurs frequently in the Roma population and molecular-genetic analysis of the TMEM70 gene is sufficient for diagnosis without need of muscle biopsy in affected children
Low-voltage Ge avalanche photodetector for highly sensitive 10Gb/s Si photonic receivers
We demonstrate low-voltage germanium waveguide avalanche photodetectors (APD) with gain-bandwidth product of 88GHz. A 7.1dB sensitivity improvement is demonstrated for an APD wire-bonded to a 10Gb/s CMOS transimpedance amplifier, at -6.2V APD bias
Improved measurements of ICRF antenna input impedance at ASDEX upgrade during ICRF coupling studies
A new set of diagnostics has been implemented on ASDEX Upgrade to measure the input impedance of the ICRF antennas, in the form of a voltage and current probe pair installed on each feeding line of every antenna. Besides allowing the measurement of the reflection coefficient Gamma of each antenna port, the probes have two advantages: first, they are located close to the antenna ports (similar to 3 m) and thus the measurements are not affected by the uncertainties due to the transmission and matching network; second, they are independent of matching conditions.
These diagnostics have been used to study the behavior of the ASDEX Upgrade antennas while changing the plasma shape (low to high triangularity) and applying magnetic perturbations (MPs) via saddle coils. Scans in the separatrix position R-sep were also performed. Upper triangularity delta(o) was increased from 0.1 to 0.3 (with the lower triangularity delta(o) kept roughly constant at 0.45) and significant decreases in vertical bar Gamma vertical bar (up to similar to 30%, markedly improving antenna coupling) and moderate changes in phase (up to similar to 5 degrees) off on each feeding line were observed approximately at delta(o) >= 0.29. During MPs (in similar to 0.5 s pulses with a coil current of 1 kA), a smaller response was observed: 6% - 7% in vertical bar Gamma vertical bar, with changes in phase of 5 apparently due to R p scans only. As 1 is usually in the range 0.8 - 0.9, this still leads to a significant increase in possible coupled power. Numerical simulations of the antenna behavior were carried out using the FELICE code; the simulation results are in qualitative agreement with experimental measurements. The results presented here complement the studies on the influence of gas injection and MPs on the ICRF antenna performance presented in [4]
Ionospheric response to the 2009 sudden stratospheric warming over the equatorial, low, and middle latitudes in the South American sector
The present study investigates the ionospheric total electron content (TEC) and F-layer response in the Southern Hemisphere equatorial, low, and middle latitudes due to major sudden stratospheric warming (SSW) event, which took place during January-February 2009 in the Northern Hemisphere. In this study, using 17 ground-based dual frequency GPS stations and two ionosonde stations spanning latitudes from 2.8°N to 53.8°S, longitudes from 36.7°W to 67.8°W over the South American sector, it is observed that the ionosphere was significantly disturbed by the SSW event from the equator to the midlatitudes. During day of year 26 and 27 at 14:00 UT, the TEC was two times larger than that observed during average quiet days. The vertical TEC at all 17 GPS and two ionosonde stations shows significant deviations lasting for several days after the SSW temperature peak. Using one GPS station located at Rio Grande (53.8°S, 67.8°W, midlatitude South America sector), it is reported for the first time that the midlatitude in the Southern Hemisphere was disturbed by the SSW event in the Northern Hemisphere.Fil: Fagundes, P. R.. Universidade do Vale do ParaĂba; BrasilFil: Goncharenko, L. P.. Massachusetts Institute of Technology; Estados UnidosFil: De Abreu, A. J.. Universidade do Vale do ParaĂba; BrasilFil: Venkatesh, K.. Universidade do Vale do ParaĂba; BrasilFil: Pezzopane, M.. Istituto Nazionale Di Geofisica E Vulcanologia; ItaliaFil: De Jesus, R.. Universidade do Vale do ParaĂba; BrasilFil: Gende, Mauricio Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias AstronĂłmicas y GeofĂsicas; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Coster, A. J.. Massachusetts Institute of Technology; Estados UnidosFil: Pillat, V. G.. Universidade do Vale do ParaĂba; Brasi
Ionospheric longitudinal variations at midlatitudes: Incoherent scatter radar observation at Millstone Hill
Incoherent scatter radar (ISR) extra-wide coverage experiments during the period of 1978–2011 at Millstone Hill are used to investigate longitudinal differences in electron density. This work is motivated by a recent finding of the US east-west coast difference in TEC suggesting a combined effect of changing geomagnetic declination and zonal winds. The current study provides strong supporting evidence of the longitudinal change and the plausible mechanism by examining the climatology of electron density Ne on both east and west sides of the radar with a longitude separation of up to 40o for different heights within 300–450 km. Main findings include: 1) The east-west difference can be up to 60% and varies over the course of the day, being positive (East side Ne > West side Ne) in the late evening, and negative (West side Ne > East side Ne) in the pre-noon. 2) The east-west difference exists throughout the year. The positive (relative) difference is most pronounced in winter; the negative (relative) difference is most pronounced in early spring and later summer. 3) The east-west difference tends to enhance toward decreasing solar activity, however, with some seasonal dependence; the enhancements in the positive and negative differences do not take place simultaneously. 4) Both times of largest positive and largest negative east-west differences in Ne are earlier in summer and later in winter. The two times differ by 12–13 h, which remains constant throughout the year. 5) Variations at different heights from 300–450 km are similar. Zonal wind climatology above Millstone Hill is found to be perfectly consistent with what is expected based on the electron density difference between the east and west sides of the site. The magnetic declination-zonal wind mechanism is true for other longitude sectors as well, and may be used to understand longitudinal variations elsewhere. It may also be used to derive thermospheric zonal winds.National Natural Science Foundation (China) (Grant 40890164)National Science Foundation (U.S.) (Grants ATM-0733510 and ATM- 6920184
3D simulations of gas puff effects on edge plasma and ICRF coupling in JET
Recent JET (ITER-Like Wall) experiments have shown that the fueling gas puffed from different locations of the vessel can result in different scrape-off layer (SOL) density profiles and therefore different radio frequency (RF) coupling. To reproduce the experimental observations, to understand the associated physics and to optimize the gas puff methods, we have carried out three-dimensional (3D) simulations with the EMC3-EIRENE code in JET-ILW including a realistic description of the vessel geometry and the gas injection modules (GIMs) configuration. Various gas puffing methods have been investigated, in which the location of gas fueling is the only variable parameter. The simulation results are in quantitative agreement with the experimental measurements. They confirm that compared to divertor gas fueling, mid-plane gas puffing increases the SOL density most significantly but locally, while top gas puffing increases it uniformly in toroidal direction but to a lower degree. Moreover, the present analysis corroborates the experimental findings that combined gas puff scenarios-based on distributed main chamber gas puffing-can be effective in increasing the RF coupling for multiple antennas simultaneously. The results indicate that the spreading of the gas, the local ionization and the transport of the ionized gas along the magnetic field lines connecting the local gas cloud in front of the GIMs to the antennas are responsible for the enhanced SOL density and thus the larger RF coupling
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