589 research outputs found

    Physical Activity and Adiposity Markers at Older Ages: Accelerometer Vs Questionnaire Data

    Get PDF
    Physical activity is critically important for successful aging, but its effect on adiposity markers at older ages is unclear as much of the evidence comes from self-reported data on physical activity. We assessed the associations of questionnaire-assessed and accelerometer-assessed physical activity with adiposity markers in older adults

    Deep Saturated Free Electron Laser Oscillators and Frozen Spikes

    Full text link
    We analyze the behavior of Free Electron Laser (FEL) oscillators operating in the deep saturated regime and point out the formation of sub-peaks of the optical pulse. They are very stable configurations, having a width corresponding to a coherence length. We speculate on the physical mechanisms underlying their growth and attempt an identification with FEL mode locked structures associated with Super Modes. Their impact on the intra-cavity nonlinear harmonic generation is also discussed along with the possibility of exploiting them as cavity out-coupler.Comment: 28 page

    Easy tuning of nanotexture and N doping of carbonaceous particles produced by spark discharge

    Get PDF
    A better understanding of the effects of carbonaceous particulates in air pollution on human health and on the transmission of viruses requires studies with artificially produced aerosols that mimic the real ones. To produce such aerosols, methods to precisely tailor the morphology as well as the physical and chemical properties of carbon-based nanomaterials are crucial. Here we describe a facile and flexible approach to produce carbon-based nanoparticles with tailored N content by spark discharge utilizing graphite rods. Carbon-based nanoparticles with different nanotexture and N doping could be obtained by simply changing dilution gas (nitrogen, argon) and dilution gas purity (99 and 99.999%). The effect of the discharge frequency (50, 300 Hz) was also explored. The carbon-based nanoparticles were characterized by Fourier transform infrared and X-ray photoelectron spectroscopy, thermogravimetric analysis, and transmission electron microscopy. We find that the nanotexture is strictly linked to the chemical reactivity and to the surface chemistry. The use of N2 as dilution gas allowed for the incorporation of significant amounts of nitrogen (5–7 wt.%) in the carbonaceous particle network mainly as pyrrolic N, graphitic N and N-oxide functional groups

    Sprayable Thermoset Nanocomposite Coatings Based on Silanized-PEG/ZnO to Prevent Microbial Infections of Titanium Implants

    Get PDF
    Post-surgery microbial infections are still one of the main reasons for implant failure, which results in very high physical and psychological pain for the patient and an increased cost for the healthcare system. A polymer nanocomposite antibacterial coating on titanium implants represents a valuable alternative to the more expensive and energy-consuming technological solutions nowadays used. In this regard, a sprayable thermoset nanocomposite composed of silanized-terminals polyethylene glycol (PEG)/ZnO nanoparticle is herein proposed. Initially, PEG's terminals' solvent-free silanization and curing are studied by Fourier Transform Infrared and mu Raman spectroscopies. Scanning Electron Microscope investigations and scratch tests have shown that the spraying procedure optimization and the oxidation treatment of the titanium substrate lead to a homogeneous coverage and improved adhesion of the coatings. The antibacterial activity is tested against not only both S. aureus and P. aeruginosa bacterial American Type Culture Collection strains, but also using very aggressive antibiotic-resistant clinical strains. Interestingly, antibacterial activity, evaluated by time-killing tests, is observed for all tested bacterial strains. Live/dead tests further confirm that 5 wt% of ZnO allows obtaining a bacteriostatic activity within 24 h, whereas a complete growth inhibition (bactericidal activity) of both tested strains is observed for coatings with 20 wt% of ZnO nanoparticles

    Identification of physical activity and sedentary behaviour dimensions that predict mortality risk in older adults: Development of a machine learning model in the Whitehall II accelerometer sub-study and external validation in the CoLaus study.

    Get PDF
    Identification of new physical activity (PA) and sedentary behaviour (SB) features relevant for health at older age is important to diversify PA targets in guidelines, as older adults rarely adhere to current recommendations focusing on total duration. We aimed to identify accelerometer-derived dimensions of movement behaviours that predict mortality risk in older populations. We used data on 21 accelerometer-derived features of daily movement behaviours in 3991 participants of the UK-based Whitehall II accelerometer sub-study (25.8% women, 60-83 years, follow-up: 2012-2013 to 2021, mean = 8.3 years). A machine-learning procedure was used to identify core PA and SB features predicting mortality risk and derive a composite score. We estimated the added predictive value of the score compared to traditional sociodemographic, behavioural, and health-related risk factors. External validation in the Switzerland-based CoLaus study (N = 1329, 56.7% women, 60-86 years, follow-up: 2014-2017 to 2021, mean = 3.8 years) was conducted. In total, 11 features related to overall activity level, intensity distribution, bouts duration, frequency, and total duration of PA and SB, were identified as predictors of mortality in older adults and included in a composite score. Both in the derivation and validation cohorts, the score was associated with mortality (hazard ratio = 1.10 (95% confidence interval = 1.05-1.15) and 1.18 (1.10-1.26), respectively) and improved the predictive value of a model including traditional risk factors (increase in C-index = 0.007 (0.002-0.014) and 0.029 (0.002-0.055), respectively). The identified accelerometer-derived PA and SB features, beyond the currently recommended total duration, might be useful for screening of older adults at higher mortality risk and for diversifying PA and SB targets in older populations whose adherence to current guidelines is low. National Institute on Aging; UK Medical Research Council; British Heart Foundation; Wellcome Trust; French National Research Agency; GlaxoSmithKline; Lausanne Faculty of Biology and Medicine; Swiss National Science Foundation

    Systematic review and meta-analysis of reduction in all-cause mortality from walking and cycling and shape of dose response relationship

    Get PDF
    BACKGROUND AND OBJECTIVE: Walking and cycling have shown beneficial effects on population risk of all-cause mortality (ACM). This paper aims to review the evidence and quantify these effects, adjusted for other physical activity (PA). DATA SOURCES: We conducted a systematic review to identify relevant studies. Searches were conducted in November 2013 using the following health databases of publications: Embase (OvidSP); Medline (OvidSP); Web of Knowledge; CINAHL; SCOPUS; SPORTDiscus. We also searched reference lists of relevant texts and reviews. STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS: Eligible studies were prospective cohort design and reporting walking or cycling exposure and mortality as an outcome. Only cohorts of individuals healthy at baseline were considered eligible. STUDY APPRAISAL AND SYNTHESIS METHODS: Extracted data included study population and location, sample size, population characteristics (age and sex), follow-up in years, walking or cycling exposure, mortality outcome, and adjustment for other co-variables. We used random-effects meta-analyses to investigate the beneficial effects of regular walking and cycling. RESULTS: Walking (18 results from 14 studies) and cycling (8 results from 7 studies) were shown to reduce the risk of all-cause mortality, adjusted for other PA. For a standardised dose of 11.25 MET.hours per week (or 675 MET.minutes per week), the reduction in risk for ACM was 11% (95% CI = 4 to 17%) for walking and 10% (95% CI = 6 to 13%) for cycling. The estimates for walking are based on 280,000 participants and 2.6 million person-years and for cycling they are based on 187,000 individuals and 2.1 million person-years. The shape of the dose-response relationship was modelled through meta-analysis of pooled relative risks within three exposure intervals. The dose-response analysis showed that walking or cycling had the greatest effect on risk for ACM in the first (lowest) exposure interval. CONCLUSIONS AND IMPLICATIONS: The analysis shows that walking and cycling have population-level health benefits even after adjustment for other PA. Public health approaches would have the biggest impact if they are able to increase walking and cycling levels in the groups that have the lowest levels of these activities. REVIEW REGISTRATION: The review protocol was registered with PROSPERO (International database of prospectively registered systematic reviews in health and social care) PROSPERO 2013: CRD42013004266

    Deconstruction of the Corso Grosseto viaduct and setup of a testing site for full scale load tests

    Get PDF
    BRIDGE|50 is a research project recently launched in Italy in the context of the Torino-Ceres construction works jointly with Politecnico di Milano, Politecnico di Torino, public authorities and private companies. The aim of the BRIDGE|50 research project is to investigate the residual structural performance of the Corso Grosseto 50-year-old prestressed concrete bridge through an experimental campaign. The dismantling and demolition procedures of Corso Grosseto viaduct are presented in this paper, including the setup of the field laboratory where several deck beams and pier caps will be tested up to collapse
    • 

    corecore