BACKGROUND Occupational exposures to ultrafine particles in the plume generated during laser hair removal procedures, the most commonly performed light based cosmetic procedure, have not been thoroughly characterized. Acute and chronic exposures to ambient ultrafine particles have been associated with a number of negative respiratory and cardiovascular health effects. Thus, the aim of this stud...

We investigated whether slowed clearance after exposure to ultrafine particles was due to a failure in alveolar macrophage phagocytosis. This was achieved by measuring the ability of a macrophage cell line (J774.2 MPhi) to phagocytose 2-microg indicator latex beads following 8-h exposures to a number of test particles. Particles utilized were fine titanium dioxide (TiO2), ultrafine titanium dio...

Recently it was speculated that ultrafine particles may translocate from deposition sites in the lungs to systemic circulation. This could lead to accumulation and potentially adverse reactions in critical organs such as liver, heart, and even brain, consistent with the hypothesis that ultrafine insoluble particles may play a role in the onset of cardiovascular diseases, as growing evidence fro...

Recently, toxicological and epidemiological studies on health effects related to particle exposure suggest that 'ultrafine particles' (particles with an aerodynamic diameter of <100 nm) may cause severe health effects after inhalation. Although the toxicological mechanisms for these effects have not yet been explained, it is apparent that measuring exposures against mass alone is not sufficient...

Air pollution is associated with cardiovascular mortality. Inhaled ultrafine particles translocate into the blood. Amine-polystyrene ultrafine particles significantly enhance experimental thrombus formation in a damaged hamster vessel and shorten the closure time in the Platelet Function Analyser. Diesel exhaust particles are thrombogenic within one hour of intratracheal instillation and shorte...

The main objective of this study was to develop parsimonious empirical models for predicting the mass and number concentrations of ultrafine particulate (UFP, aerodynamic diameter < 0.1 or 0.18 microm) in the atmospheric environment. We found strong correlations existed between the mass/number concentration of UFP and the mass concentration of PM(2.5) (aerodynamic diameter < 2.5 microm) by fitt...

It is well known that when coarse-grained metals undergo severe plastic deformation to be transformed into nano-grained metals, their ductility is reduced. However, there are no ductile fracture criteria developed based on grain refinement. In this paper, we propose a new relationship between ductile fracture and grain refinement during deformation, considering factors besides void nucleation a...

fabrication of ultrafine grained materials by imposing severe plastic deformation for improvement of mechanical and physical properties of metals has been the focus of many researches over the past few years. in this process, a sheet is subjected to repetitive shear deformation conditions by utilizing asymmetrically grooved and flat dies through alternate pressing. in this study, a 2mm thick co...

Materials with ultrafine-grained structure and unique physical and mechanical properties can be obtained by methods of severe plastic deformation, which include processes of asymmetric rolling (AR). Asymmetric rolling is a very effective way to create ultrafine-grained structures of metals and alloys. Since the asymmetric rolling is a continuous process, it has great potential for industrial pr...

INTRODUCTION We investigated whether adding ultrafine (nano-scale) oxygen-carrying bubbles to water concurrently with dissolved carbon-dioxide (CO2) could result in safe, long-duration anesthesia for fish. RESULTS To confirm the lethal effects of CO2 alone, fishes were anesthetized with dissolved CO2 in 20°C seawater. Within 30 minutes, all fishes, regardless of species, died suddenly due to ...