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...

No abstract

Uranium in plutonium dioxide is measured spectrophotometrically as the Arsenazo-I complex after separation by anion exchange resin in a hydrochloric acid medium. The sample is dissolved in 11M HC1 at 300°C in a sealed tube or, alternatively, by repeated fumings with HNO 3 -HF-H 2 SO 4 mixtures. A sample size of 70 mg permits the determination of 300 to 1100 ppm of uranium with a relative standard deviation of 10%. At the 1400 to 3000 ppm level the relative standard deviation is 5%. The procedure is normally free from interferences.

No abstract

Lithium tritide-deuteride samples are enclosed in a copper foil and decomposed by heating to 850°C in a copper reaction tube in vacuum. The temperature and pressure of the evolved gas, collected in a measured volume using a Toepler pump, are measured to determine the total moles of gas released from the sample. The gas is transferred to a removable sample bulb and, if required, analyzed for gaseous constituents by mass spectrometry. Based on 14 total gas determinations for a lithium deuteride sample, the calculated relative standard deviation was 1.0% and the estimated bias was Pressure regulator, one, low-pressure, capable of regulation at 2.5 to 3.7 kPa (10-15 in. of water); and one, capable of regulation at 103 kPa (15 psi). Spatula, vibrating type preferred for loading copper foils. Total gas analysis apparatus, consisting of the following items, assembled as shown in Fig. 1. Deaiccant tube, borosilicate glass, filled with anhydrous magnesium perchlorate and plugged with glass wool at each end to contain reagent dust. Furnace, resistance, for heating 9.5-mm (0.375-in.) copper tube to 850°C. Laboratory jack, for adjusting furnace height. Magnet, for operating sample dumper. Mercury diffusion pump, pumping speed ~120 i/s or faster. Mercury reservoir Micromanometer, with sensor head that can be used with tritium (MKS single-sided head or equivalent). Reaction tube, made from hard-drawn copper tubing, 9.5-mm (0.375-in.)-o.d., 1.65-mm (0.065-in.) wall thickness, and 203-mm (8-in.)-long, sealed at one end by flowing helium through the tube while heating the end in a gas-oxygen flame and striking with a hammer. A copper coupling is hard soldered to the other end and the ridge left by the inserted tube is beveled using a 9.5-mm (0.375-in.) counter sink. The other end of the coupling is hard soldered to a Kovar metal-glass seal connected to a 14/35 standard-taper borosilicate glass outer joint. Sample bulbs, 25-m£, equipped with pressure stopcock. Sample dumper Solenoid valves, two, 6-W, 115/230-V, 172-kPa (25-psi), 6.35-mm (0.25-in.) pipe, 5.55-mm (0.218-in.) orifice for activating Toepler pump. Stopcocks, five, straight-bore, 4-mm; two, oblique-bore, 4-mm; and two, oblique-bore, 3-way, 4-mm. Thermocouple gauges, two, 0-to 133-Pa (1-torr). Thermometer, digital or otherwise, readable to 0.1°C. Timers, two, electric, 30-s, wired to solenoid valves so that one controls the vacuum half of the Toepler pump cycle and the other controls the pressure half of the cycle. Toepler pump, 250-m£, with 4-mm, straight-bore, stopcock inserted between bulbs. Tubing, stainless steel, 19-mm (0.75-in.)-o.d. Valves, three, stainless-steel, bellows, with 19-mm (0.75-in.) tube connections, and two metering valves, with 6.35-mm (0.25-in.) tube connections. Reagents Argon, tank. Desiccant, magnesium perchlorate, anhydrous. Grease, silicone. Mercury, distilled. Caution Any work that involves the handling of tritium-containing materials should be done only under approved safe conditions and in laboratories designed for adequate protection of th...