Discussion Abounds on the Potential Carcinogenic Risks Associated With the Use of UV Curing Lamps for Permanent Nail Polish.

BACKGROUND: Controversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. OBJECTIVE: To evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. MATERIAL AND METHODS: The emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. RESULTS: The high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. CONCLUSIONS: The exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.

Exposure to UV Radiation in Lifeguards on Barcelona's Beaches: An Underestimated Occupational Risk. / [Artículo traducido] Exposición a radiación ultravioleta en socorristas de las playas de Barcelona: un riesgo laboral infravalorado.

BACKGROUND: The development of skin cancer is closely related to high exposure to UV radiation. Lifeguards are at an increased risk of excessive sun exposure. OBJECTIVES: The main objective of this study was to measure the exposure of Barcelona's beach lifeguards to UV radiation. METHODS: Measurements in the work chair were taken every 30min on a typical working day from 10:45 am to 19:15 pm. These measurements were carried out on four different days. These data were used to calculate the erythematous doses received during working hours, as well as those potentially received throughout the summer season. Vitamin D production was also estimated for the four days that the radiation received was measured, and the amount generated was calculated for the entire summer season. RESULTS: Exposure to UV radiation among Barcelona lifeguards far exceeds safety limits. In some locations, the exposure to UVB radiation is more than 16 times the minimum erythematous dose for phototype II skin. LIMITATIONS: This study assessed the radiation received during only four days. However, is a much higher number than most of the published papers. CONCLUSION: Although the health risks of excessive exposure to UV radiation are known, Barcelona's beach lifeguards are insufficiently protected.

Design and optimization methodology for different 3D processed materials (PLA, ABS and carbon fiber reinforced nylon PA12) subjected to static and dynamic loads.

This research presents a methodology for the design and optimization of 3D printed parts with material extrusion (MEX) technology with three different commercial materials: PLA, ABS and N + CF (PA12) subjected to tensile and fatigue stresses, which included three stages: pretreatment, design of experiments and sequential optimization by statistical modeling. In the pretreatment stage, mainly the printing control factors (inner layer and contour height, printing speed, extrusion temperature, nozzle, infill arrangement and printing orientation) were determined; then, factors to optimize tensile strength as a function of printing pattern (linear, 3D, hexagonal), infill percentage (33%, 66%, 100°) and printing orientation (+45°/-45°, 0°/90°) were evaluated. Fatigue analysis was performed as a function of impression orientation using 100% infill, linear impression pattern, 5 Hz and a load range between 90 and 50% UTS. Optimization of tensile strength resulted in parts that exceeded the UTS of their corresponding filament, leading to infinite life relative to fatigue tests. Results were presented for fatigue life prediction based on Weibull analysis, Basquins model and a multivariate response surface correlation analysis. The best fatigue behavior was related to the optimized tensile strength, the infill pattern applied to the printing orientation and the intrinsic properties of ABS (1 × 107cycles, stress up to 20 MPa). With respect to the other materials, a good fatigue behavior was highlighted at the number of cycles achieved 1 × 106 (stress up to 18 MPa) and 1 × 105 (stress up to 24 MPa) for N + CF and PLA, respectively. This study contributes to a better understanding of how printing parameters correlate with tensile and fatigue properties.

Raman spectroscopy and molecular dynamics simulations of aqueous two-phase systems for the purification of phosphoric acid.

In this work, Raman spectroscopy and molecular dynamics simulations were used to elucidate key interactions between polyethylene glycol (PEG) and phosphoric acid (H3PO4) in aqueous two-phase systems for the extraction of phosphoric acid. Extensive molecular dynamics simulations were performed, and radial distribution functions as well as hydrogen bonds between PEG and other molecules were measured. Experimental data were used in combination with the slope method to infer PEG-H3PO4 interactions, and the interpretation is consistent with molecular simulation results. Based on our experimental and simulation results, we propose a solvation mechanism governed by hydrogen bonding interactions: at low concentrations of H3PO4 within the polymer-rich aqueous solution, entropy dominates and phosphoric acid molecules have weak interactions with PEG; as the concentration of phosphoric acid increases above a certain critical value, enthalpy dominates with PEG molecules interacting strongly with H3PO4 molecules via hydrogen bonds.

Exposure to UV Radiation in Lifeguards on Barcelona's Beaches: An Underestimated Occupational Risk.

BACKGROUND: The development of skin cancer is closely related to high exposure to UV radiation. Lifeguards are at an increased risk of excessive sun exposure. OBJECTIVES: The main objective of this study was to measure the exposure of Barcelona's beach lifeguards to UV radiation. METHODS: Measurements in the work chair were taken every 30min on a typical working day from 10:45 am to 19:15 pm. These measurements were carried out on four different days. These data were used to calculate the erythematous doses received during working hours, as well as those potentially received throughout the summer season. Vitamin D production was also estimated for the four days that the radiation received was measured, and the amount generated was calculated for the entire summer season. RESULTS: Exposure to UV radiation among Barcelona lifeguards far exceeds safety limits. In some locations, the exposure to UVB radiation is more than 16 times the minimum erythematous dose for phototype II skin. LIMITATIONS: This study assessed the radiation received during only four days. However, is a much higher number than most of the published papers. CONCLUSION: Although the health risks of excessive exposure to UV radiation are known, Barcelona's beach lifeguards are insufficiently protected.

Heat losses in a trapezoidal cavity receiver of a linear Fresnel collector: A CFD approach.

This paper presents a thermal study of a cavity receiver designed for a Fresnel-type linear solar collector (LFC). The study utilizes a two-dimensional computational fluid dynamics (CFD) model implemented in ANSYS Fluent. The thermal behavior of air inside the cavity for a Fresnel collector is extensively examined. The receiver consists of a trapezoidal cavity with a set of six parallel absorber tubes, through which a thermal fluid circulates. The cavity has aluminum reflectors on the inner walls and glass window closing the aperture facing the primary reflectors of the solar collector. The two-dimensional numerical model represents a cross-section of the receiver, and aims to provide numerical results that allow to provide algebraic correlations for predicting heat losses in the receiver from the wall temperature of each of the six individual absorber tubes that compose it. The developed model is transient, utilizing the k-ε turbulent model. In addition, the study is completed with an analysis of the behavior of the air surrounding and inside the cavity, to evaluate its thermal performance. For this purpose, the velocity and temperature contours obtained with the two-dimensional model are discussed. Correlations are obtained to know the heat flux between the tubes and the heat loss through the window for any combination of temperatures for each pair of tubes, which has not been yet studied in the literature. The study reveals that radiative losses contribute to 81% of the total heat losses, with the outer tubes temperature being the main responsible for these losses. Furthermore, a dimensionless analysis examines the relationship between the Nusselt and Rayleigh numbers in comparison to reference problems based on canonical geometries dominated by buoyancy-driven flows. The performance is found to be similar to that of a downward hot flat plate.

Phase Space Reconstruction from Accelerator Beam Measurements Using Neural Networks and Differentiable Simulations.

Characterizing the phase space distribution of particle beams in accelerators is a central part of understanding beam dynamics and improving accelerator performance. However, conventional analysis methods either use simplifying assumptions or require specialized diagnostics to infer high-dimensional (>2D) beam properties. In this Letter, we introduce a general-purpose algorithm that combines neural networks with differentiable particle tracking to efficiently reconstruct high-dimensional phase space distributions without using specialized beam diagnostics or beam manipulations. We demonstrate that our algorithm accurately reconstructs detailed 4D phase space distributions with corresponding confidence intervals in both simulation and experiment using a limited number of measurements from a single focusing quadrupole and diagnostic screen. This technique allows for the measurement of multiple correlated phase spaces simultaneously, which will enable simplified 6D phase space distribution reconstructions in the future.

The spectrum of [Formula: see text]-soundness.

We study the [Formula: see text]-soundness spectra of theories. Given a recursively enumerable extension [Formula: see text] of [Formula: see text], [Formula: see text] is defined as the set of all 2-ptykes on which [Formula: see text] is correct about well foundedness. This is a measure of how close [Formula: see text] is to being [Formula: see text]-sound. We carry out a proof-theoretic classification of theories according to [Formula: see text], as well as a characterization of the sets of the form [Formula: see text]. Many of the results generalize to [Formula: see text] greater than 3. This article is part of the theme issue 'Modern perspectives in Proof Theory'.

Low aerobic capacity in McArdle disease: A role for mitochondrial network impairment?

BACKGROUND: McArdle disease is caused by myophosphorylase deficiency and results in complete inability for muscle glycogen breakdown. A hallmark of this condition is muscle oxidation impairment (e.g., low peak oxygen uptake (VO2peak)), a phenomenon traditionally attributed to reduced glycolytic flux and Krebs cycle anaplerosis. Here we hypothesized an additional role for muscle mitochondrial network alterations associated with massive intracellular glycogen accumulation. METHODS: We analyzed in depth mitochondrial characteristics-content, biogenesis, ultrastructure-and network integrity in skeletal-muscle from McArdle/control mice and two patients. We also determined VO2peak in patients (both sexes, N = 145) and healthy controls (N = 133). RESULTS: Besides corroborating very poor VO2peak values in patients and impairment in muscle glycolytic flux, we found that, in McArdle muscle: (a) damaged fibers are likely those with a higher mitochondrial and glycogen content, which show major disruption of the three main cytoskeleton components-actin microfilaments, microtubules and intermediate filaments-thereby contributing to mitochondrial network disruption in skeletal muscle fibers; (b) there was an altered subcellular localization of mitochondrial fission/fusion proteins and of the sarcoplasmic reticulum protein calsequestrin-with subsequent alteration in mitochondrial dynamics/function; impairment in mitochondrial content/biogenesis; and (c) several OXPHOS-related complex proteins/activities were also affected. CONCLUSIONS: In McArdle disease, severe muscle oxidative capacity impairment could also be explained by a disruption of the mitochondrial network, at least in those fibers with a higher capacity for glycogen accumulation. Our findings might pave the way for future research addressing the potential involvement of mitochondrial network alterations in the pathophysiology of other glycogenoses.

Differentiable Preisach Modeling for Characterization and Optimization of Particle Accelerator Systems with Hysteresis.

Future improvements in particle accelerator performance are predicated on increasingly accurate online modeling of accelerators. Hysteresis effects in magnetic, mechanical, and material components of accelerators are often neglected in online accelerator models used to inform control algorithms, even though reproducibility errors from systems exhibiting hysteresis are not negligible in high precision accelerators. In this Letter, we combine the classical Preisach model of hysteresis with machine learning techniques to efficiently create nonparametric, high-fidelity models of arbitrary systems exhibiting hysteresis. We experimentally demonstrate how these methods can be used in situ, where a hysteresis model of an accelerator magnet is combined with a Bayesian statistical model of the beam response, allowing characterization of magnetic hysteresis solely from beam-based measurements. Finally, we explore how using these joint hysteresis-Bayesian statistical models allows us to overcome optimization performance limitations that arise when hysteresis effects are ignored.

Sun exposure and protection habits in transplant athletes: An international survey.

BACKGROUND: Transplant recipients are particularly prone to the development of skin cancer, and overexposure to UV radiation during outdoor activities increases the risk of carcinogenesis. OBJECTIVE: The aim of this study was to analyze sun-related behaviors and knowledge in transplant athletes, examine the frequency of sunburns, and explore associations with a history of skin cancer. MATERIALS AND METHODS: Cross-sectional descriptive study. Participants (n = 170) in the XXI World Transplant Games from >50 countries completed a questionnaire on sun protection habits and knowledge, type of transplant, immunosuppressive therapy, and personal history of skin cancer. RESULTS: The most common transplanted organs were the kidney (n = 79), the liver (n = 33), and the heart (n = 31). Overall, 61.3% of athletes had been doing sport for >15 years and 79.5% spent >1-2 h a day outdoors. Fifteen % of athletes had a history of skin cancer. The prevalence of sunburn in the previous year was 28.9%, higher in athletes aged <50 years (37.2%); without a primary school education (58.3%), not taking cyclosporin (32.6%), and athletes who played basketball (75%). The main sun protection measures used were sunscreen (68.9%) and sunglasses (67.3%). Use of a hat or cap was the only measure significantly associated with a reduced prevalence of sunburn. CONCLUSIONS: Despite high awareness that sun exposure increases the risk of skin cancer, sunburn was common in transplant athletes. Efforts should be made to strengthen multidisciplinary sun protection education strategies and ensure periodic dermatologic follow-up to prevent sun-induced skin cancer in this population.

Effects of Hypoxia on Selected Psychophysiological Stress Responses of Military Aircrew.

There is a lack of information on the psychophysiological response of pilots under hypoxic conditions. The study of the physiological, psychological, cardiorespiratory, neurological, behavioural, sensory, and cognitive symptoms that may appear during training in hypobaric chambers is essential to optimize the training processes of aircrew members. Thus, the present study is aimed at analyzing the psychophysiological responses of aircrew members in an incremental hypoxia training protocol. Psychophysiological responses of 44 aircrew members (34 males and 10 females) in an incremental hypoxia training protocol (3 minutes at 0 meters, 8 minutes at 5,000 meters, and maximum time at 7500 meters) were measured. Results suggested that the incremental hypoxia training protocol did not affect cortical arousal and handgrip strength; however, it increased the sympathetic tone, perceived stress, perceived effort, and heart rate and decreased forced expiratory volume and blood oxygen saturation. Thus, we concluded that acute hypoxic hypobaric exposure leads to decreased parasympathetic tone, blood oxygen saturation, and maximal spirometry values, without negatively affecting handgrip strength and cortical arousal. This information will lead to find specific training systems that meet the real needs of aircrew.

Use of cardiovascular polypills for the secondary prevention of cerebrovascular disease. / Uso de la polipíldora cardiovascular en la prevención secundaria de la enfermedad cerebrovascular.

INTRODUCTION: There is little control of cardiovascular (CV) risk factors in secondary prevention after an ischaemic stroke, in part due to a lack of adherence to treatment. The CV polypill may contribute to proper treatment adherence, which is necessary for CV disease prevention. This study aimed to establish how and in what cases the CV polypill should be administered. METHODS: A group of 8 neurologists drafted consensus recommendations using structured brainstorming and based on their experience and a literature review. RESULTS: These recommendations are based on the opinion of the participating experts. The use of the CV polypill is beneficial for patients, healthcare professionals, and the health system. Its use is most appropriate for atherothrombotic stroke, lacunar stroke, stroke associated with cognitive impairment, cryptogenic stroke with CV risk factors, and silent cerebrovascular disease. It is the preferred treatment in cases of suspected poor adherence, polymedicated patients, elderly people, patients with polyvascular disease or severe atherothrombosis, young patients in active work, and patients who express a preference for the CV polypill. Administration options include switching from individual drugs to the CV polypill, starting treatment with the CV polypill in the acute phase in particular cases, use in patients receiving another statin or an angiotensin ii receptor antagonist, or de novo use if there is suspicion of poor adherence. Nevertheless, use of the CV polypill requires follow-up on the achievement of the therapeutic objectives to make dose adjustments. CONCLUSIONS: This document is the first to establish recommendations for the use of the CV polypill in cerebrovascular disease, beyond its advantages in terms of treatment adherence.

Prediction of pre-eclampsia in twin pregnancy by maternal factors and biomarkers at 11-13 weeks' gestation: data from EVENTS trial.

OBJECTIVES: First, to validate a previously developed model for screening for pre-eclampsia (PE) by maternal characteristics and medical history in twin pregnancies; second, to compare the distributions of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum pregnancy-associated plasma protein-A (PAPP-A) in twin pregnancies that delivered with PE to those in singleton pregnancies and to develop new models based on these results; and, third, to examine the predictive performance of these models in screening for PE with delivery at < 32 and < 37 weeks' gestation. METHODS: Two datasets of prospective non-intervention multicenter screening studies for PE in twin pregnancies at 11 + 0 to 13 + 6 weeks' gestation were used. The first dataset was from the EVENTS (Early vaginal progesterone for the preVention of spontaneous prEterm birth iN TwinS) trial and the second was from a previously reported study that examined the distributions of biomarkers in twin pregnancies. Maternal demographic characteristics and medical history from the EVENTS-trial dataset were used to assess the validity of risks from our previously developed model. The combined data from the first and second datasets were used to compare the distributional properties of log10 multiples of the median (MoM) values of UtA-PI, MAP, PlGF and PAPP-A in twin pregnancies that delivered with PE to those in singleton pregnancies and develop new models based on these results. The competing-risks model was used to estimate the individual patient-specific risks of delivery with PE at < 32 and < 37 weeks' gestation. Screening performance was measured by detection rates (DR) and areas under the receiver-operating-characteristics curve. RESULTS: The EVENTS-trial dataset comprised 1798 pregnancies, including 168 (9.3%) that developed PE. In the validation of the prior model based on maternal characteristics and medical history, calibration plots demonstrated very good agreement between the predicted risks and the observed incidence of PE (calibration slope and intercept for PE < 32 weeks were 0.827 and 0.009, respectively, and for PE < 37 weeks they were 0.942 and -0.207, respectively). In the combined data, there were 3938 pregnancies, including 339 (8.6%) that developed PE and 253 (6.4%) that delivered with PE at < 37 weeks' gestation. In twin pregnancies that delivered with PE, MAP, UtA-PI and PlGF were, at earlier gestational ages, more discriminative than in singleton pregnancies and at later gestational ages they were less so. For PAPP-A, there was little difference between PE and unaffected pregnancies. The best performance of screening for PE was achieved by a combination of maternal factors, MAP, UtA-PI and PlGF. In screening by maternal factors alone, the DR, at a 10% false-positive rate, was 30.6% for delivery with PE at < 32 weeks' gestation and this increased to 86.4% when screening by the combined test; the respective values for PE < 37 weeks were 24.9% and 41.1%. CONCLUSIONS: In the assessment of risk for PE in twin pregnancy, we can use the same prior model based on maternal characteristics and medical history as reported previously, but in the calculation of posterior risks it is necessary to use the new distributions of log10 MoM values of UtA-PI, MAP and PlGF according to gestational age at delivery with PE. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Cardiac function in gestational diabetes mellitus: A longitudinal study from fetal life to infancy.

OBJECTIVE: To determine whether cardiac functional and structural changes in fetuses of mothers with gestational diabetes mellitus (GDM) persist in the offspring beyond the neonatal period. DESIGN: Longitudinal study. SETTING: Fetal Medicine Unit in a UK teaching hospital. METHODS: 73 women with GDM and 73 women with uncomplicated pregnancy were recruited and fetal cardiac scans were performed at 35-36 weeks' gestation. Repeat echocardiogram was performed in their offspring during infancy. MAIN OUTCOME MEASURES: Fetal and infant cardiac functional and structural changes. RESULTS: Fetuses of mothers with GDM, compared with controls, had more globular right ventricles (sphericity index 0.7, interquartile range [IQR] 0.6/0.7 versus 0.6, IQR 0.5/0.6, P < 0.001) and reduced right global longitudinal systolic strain (-16.4, IQR -18.9/-15.3 versus -18.5, IQR -20.6/-16.8, P = 0.001) and left global longitudinal systolic strain (-20.1, IQR -22.5/-16.9 versus -21.3, IQR -23.5/-19.5), P = 0.021). In the GDM group, compared with controls, in infancy there was higher left ventricular E/e' (8.7, IQR 7.3/9.7 versus 7.9 IQR, 6.8/8.9 P = 0.011) and lower left ventricular global longitudinal systolic strain (-21.0, IQR -22.5/-19.4 versus -22.3, IQR -23.5/-20.7, P = 0.001) and tricuspid annular plane systolic excursion (13.8, IQR 12.7/16.1 versus 15.2, IQR 13.8/16.8, P = 0.003). These differences remained following multivariable analysis. CONCLUSION: Gestational diabetes mellitus is associated with alterations in fetal cardiac function and structure compared with controls and persistent cardiac changes in infancy. TWEETABLE ABSTRACT: Gestational diabetes mellitus, even when well controlled, is associated with fetal cardiac changes and these persist in infancy.

Could academic experience modulate psychophysiological stress response of biomedical sciences students in laboratory?

The aim of the present research was to analyse the subjective and objective psychophysiological stress response of experienced and non-experienced Pharmacy and Biotechnology students in laboratory practices. We analysed in 82 Pharmacy and Biotechnology degree students divided into two groups (non-experienced: n: 53; experienced: n: 29) the autonomic stress response by the analysis of heart rate variability (HRV) before, during and after and distress perception before and after a laboratory practice. Results showed how students in both groups presented a large anticipatory anxiety response at the beginning of the practise (low HRV values). During the entire laboratory practice, non-experienced students showed a maintained sympathetic modulation while experienced students presented a higher parasympathetic modulation (high HRV values) consistent with a habituation process. Laboratory practise performed by Pharmacy and Biotechnology students produced an anticipatory anxiety response independently of their experience, but, non-experienced students showed a lower habituation response in both subjective and objective stress records than experienced students at the end of the laboratory practice.