With increasing concerns over the rise of atmospheric particulate pollution globally and its impact on systemic health and skin ageing, we have developed a pollution model to mimic particulate matter trapped in sebum and oils creating a robust (difficult to remove) surrogate for dirty, polluted skin. OBJECTIVE: To evaluate the cleansing efficacy/protective effect of a sonic brush vs. manual cleansing against particulate pollution (trapped in grease/oil typical of human sebum). METHODS:The pollution model (Sebollution; sebum pollution model; SPM) consists of atmospheric particulate matter/pollution combined with grease/oils typical of human sebum. Twenty subjects between the ages of 18-65 were enrolled in a single-centre, cleansing study comparisons between the sonic cleansing brush (normal speed) compared to manual cleansing. Equal amount of SPM was applied to the centre of each cheek (left and right). Method of cleansing (sonic vs. manual) was randomized to the side of the face (left or right) for each subject. Each side was cleansed for five-seconds using the sonic cleansing device with sensitive brush head or manually, using equal amounts of water and a gel cleanser. Photographs (VISIA-CR, Canfield Imaging, NJ, USA) were taken at baseline (before application of the SPM), after application of SPM (precleansing), and following cleansing. Image analysis (ImageJ, NIH, Bethesda, MD, USA) was used to quantify colour intensity (amount of particulate pollutants on the skin) using a scale of 0 to 255 (0 = all black pixels; 255 = all white pixels). Differences between the baseline and post-cleansing values (pixels) are reported as the amount of SPM remaining following each method of cleansing. RESULTS: Using a robust cleansing protocol to assess removal of pollutants (SPM; atmospheric particulate matter trapped in grease/ oil), the sonic brush removed significantly more SPM than manual cleansing (P < 0.001). While extreme in colour, this pollution method easily allows assessment of efficacy through image analysis. ResumeAvec l'augmentation des preoccupations sur l'augmentation de la pollution particulaire atmospherique a l'echelle mondiale et son impact sur la sante systemique et le vieillissement de la peau, nous avons developpe un modele de pollution pour imiter la matiere particulaire piegee dans le sebum et les huiles creant une robuste substitution (difficile a enlever) de la peau polluee sale. OBJECTIF: Evaluer l'efficacite de nettoyage et de l'effet protecteur d'une brosse sonique vs le nettoyage manuel contre la pollution particulaire (piegee dans la graisse/l'huile typique de sebum humain). M ETHODES: Le modele de la pollution (Sebollution; Sebum Pollution Model; SPM) se compose de l'atmosphere de particules, de la pollution associee a la graisse et aux huiles typiques du sebum humain. Vingt sujetsâges de 18 a 65 ans etaient inscrits dans une etude monocentrique de nettoyage en comparant la brosse de nettoyage sonique (vitesse normale) par rapport au nettoyage manuel. Des quantites egales de SPM ont et...

The invariant choice of L-amino acids and D-ribose RNA for biological translation requires explanation. Here we study this chiral choice using mixed, equimolar D-ribose RNAs having 15, 18, 21, 27, 35, and 45 contiguous randomized nucleotides. These are used for simultaneous affinity selection of the smallest bound and eluted RNAs using equal amounts of L-and D-His immobilized on an achiral glass support, with racemic histidine elution. The experiment as a whole therefore determines whether RNA containing D-ribose binds L-histidine or D-histidine more easily (that is, by using a site that is more abundant/ requires fewer nucleotides). The most prevalent/smallest RNA sites are reproducibly and repeatedly selected and there is a four-to sixfold greater abundance of L-histidine sites. RNA's chiral D-ribose therefore yields a more frequent fit to L-histidine. Accordingly, a D-ribose RNA site for L-His is smaller by the equivalent of just over one conserved nucleotide. The most prevalent L-His site also performs better than the most frequent D-His site-but rarer D-ribose RNAs can bind D-His with excellent affinity and discrimination. The prevalent L-His site is one we have selected before under very different conditions. Thus, selection is again reproducible, as is the recurrence of cognate coding triplets in these most probable L-His sites. If our selected RNA population were equilibrated with racemic His, we calculate that L-His would participate in seven of eight His:RNA complexes, or more. Thus, if D-ribose RNA were first chosen biologically, translational L-His usage could have followed.

The increased risk of wildfires and associated smoke exposure in the United States is a growing public health problem, particularly along the Wildland–Urban Interface (WUI). Using the measure of fire danger, the Energy Release Component, we define fire danger as the onset and duration of fire season, in the continental US, between 1979 and 2016. We then combine the measure of fire danger with census data to quantify changes in population fire exposure across the WUI. We determined that the largest increases in fire danger were observed in the Southwest, Intermountain, and Pacific Southwest regions. The increased fire danger, specifically during peak fire season, accounted for 6.1 more fires each year and 78,000 more acres burned each year, underscoring the link between fire danger and the risks of large fire occurrence and burn acreage. Finally, we observed significant population growth (121.2% between 1990 and 2010) within high-danger WUI areas, further implying significant increases in potential fire exposure.

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