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Electromagnetic shielding attenuation (ESA) properties of carbon nanotubes/polymer nanocomposite films, in the super high frequency (SHF) X-band (7-12 GHz) domain are studied. The nanocomposite films consisted of thermoset polyurethane (PU) resin blended with single-walled carbon nanotubes (SWCNTs) mats, and deposited on fused quartz substrates. Two different approaches were used to achieve the nanocomposite films, namely (i) through the on-substrate 'all-laser' growth approach of SWCNTs directly onto substrate, followed by their infiltration by the PU resin, and (ii) by appropriately dispersing the chemically-purified SWCNTs (in the soot form) into the PU matrix and their subsequent deposition onto quartz substrates by means of a solvent casting process. Characterizations of the ESA properties of the developed nanocomposite films show that they exhibit systematically a deep shielding band, centered at around 9.5 GHz, with an attenuation as high as |- 30| dB, recorded for SWCNT loads of 2.5 wt. % and above. A direct correlation is established between the electrical conductivity of the nanocomposite films and their electromagnetic shielding capacity. The SWCNTs/PU nanocomposites developed here are highly promising shielding materials as SHF notch filters, as their ESA capacity largely exceeds the target value of |- 20| dB generally requested for commercial applications. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To identify personal and environmental predictors of the most disrupted participation domains in people with myotonic dystrophy type 1 (DM1). DESIGN: Cross-sectional study. SETTING: Outpatient neuromuscular clinic. PARTICIPANTS: Adults (n=200; 121 women), age 18 years or older (mean age, 47 y), with a confirmed diagnosis of DM1 were selected from the registry of a neuromuscular clinic (N=416). Fifty-two participants had the mild phenotype and 148 the adult phenotype. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Social participation in mobility, housing, employment, and recreation was assessed with the Life Habits Measure. Disrupted participation was based on whether help was needed in performing most life habits because of incapacities or environmental barriers. Environmental factors were assessed by using the Measure of the Quality of the Environment. Personal factors were assessed with standardized instruments including the Berg Balance Scale, the Krupp Fatigue Severity Scale, and manual muscle testing. RESULTS: A large proportion of participants (45%-61%) reported disrupted participation in all 4 domains. Lower-extremity strength (odd ratios [OR], 15.0-5.5; P<.050) and higher fatigue (OR, 6.0-2.6; P<.05) were present in participants with disrupted participation. With regard to environmental factors, family support (OR, 3.6-2.5; P<.05) and public services (OR, 2.8-2.2; P<.05) were perceived as barriers for participants with disrupted participation in most domains. CONCLUSIONS: This study identified personal and environmental factors that may influence the trajectory toward disrupted participation in individuals with DM1. Fatigue, strength, family support, and public services were found to be independent predictors of disrupted participation. Copyright © 2008 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation [ABSTRACT FROM AUTHOR]

Our aim was to compare the circadian phase characteristics of healthy adolescent and young adult males in a naturalistic summertime condition. A total of 19 adolescents (mean age 15.7 years) and 18 young adults (mean age 24.5 years) with no sleep problems took part in this study. Two-night polysomnographic (PSG) sleep recordings and 24h secretion patterns of urinary 6-sulfatoxymelatonin were monitored in all 37 subjects. Sleep-wake patterns were initially assessed at home using a standard sleep diary. Circadian assessment included the measure of dim light melatonin offset (DLMOff) and the morningness-eveningness (M/E) questionnaire. As expected, compared to young adults, adolescents habitually spent more nocturnal time in bed and spent more time (and percentage) in delta sleep. No difference was found between adolescents and young adults on multiple sleep latency test (MSLT) sleep onset latencies, M/E, melatonin secretion measures (24h total, nighttime, daytime, and night ratio), and DLMOff. For the subjects as a whole, correlational analyses revealed a significant association between the DLMOff and M/E and between both these phase markers and habitual bedtimes, habitual rising times, and melatonin secretion measures (daytime levels and the night ratio). No association was found between phase markers and daytime sleepiness or sleep consolidation parameters such as sleep efficiency or number of microarousals. These results together indicate that adolescents and young adults investigated during summertime showed similar circadian phase characteristics, and that, in these age groups, an evening phase preference is associated with a delayed melatonin secretion pattern and delayed habitual sleep patterns without a decrease in sleep consolidation or vigilance. (Chronobiology International, 17(4), 489–501, 2000) [ABSTRACT FROM AUTHOR]

Objectives: To assess the reliability of the Epworth Sleepiness Scale (ESS), Daytime Sleepiness Scale (DSS), Chalder Fatigue Scale (CFS), and Krupp's Fatigue Severity Scale (KFSS) in patients with myotonic dystrophy type 1 (DM1).Methods: In total, 27 patients with DM1 were administered the questionnaires on two occasions, with a 2 week interval. Internal consistency and test retest reliability were measured using intraclass correlation coefficients (ICCs), and Cronbach's alpha, Cohen's kappa, and Goodman-Kruskal's gamma coefficients.Results: Internal consistency of the CFS and KFSS were adequate (alpha > 0.70) but that of the ESS was weak (alpha = 0.24). Both daytime sleepiness and fatigue rating scales showed significant test retest reliability. Test retest reliability for individual items revealed inconsistencies for some ESS and CFS items.Conclusions: Reliability of the CFS, DSS, and KFSS was high, allowing their use for individual patients with DM1, but that of the ESS was lower, rendering its current usage in DM1 questionable. Fatigue rating scales such as the KFSS, which are based on the behavioural consequences of fatigue, may constitute a more accurate and comprehensive measure of fatigue severity in the DM1 population. [ABSTRACT FROM AUTHOR]