The current carcinogenicity study with female rats focused on the toxicity and carcinogenicity of intratracheally instilled fine and ultrafine granular dusts. The positive control, crystalline silica, elicited the greatest magnitude and progression of pulmonary inflammatory reactions, fibrosis and the highest incidence of primary lung tumors (39.6%). Addition of poly-2-vinylpyridine-N-oxide dec...

Ultrafine particles (< 0.10 microm in diameter) are present in great number in polluted urban air, thus posing a potential health risk. In this study, the total deposition fraction (TDF) of ultrafine aerosols with a narrow size distribution (number median diameter NMD = 0.04-0.1 microm and geometric standard deviation sigma(g) = approximately 1.3) was measured in a group of young healthy adults...

In this experimental study, aerosol methods for producing titanium dioxide powders and increasing our knowledge of particle and crystal formation have been developed. Powders and ultrafine particles of titanium oxide were produced by an aerosol droplet decomposition route in tubular laminar flow reactors in air and nitrogen atmospheres. Reactor temperatures up to 1500°C were used with residence...

Recent research has indicated that the toxicity of inhaled ultrafine particles may be associated with the size of discrete particles deposited in the lungs. However, it has been speculated that in some occupational settings rapid coagulation will lead to relatively low exposures to discrete ultrafine particles. Investigation of likely occupational exposures to ultrafine particles following the ...

Well-documented air pollution episodes throughout recent history have led to deaths among individuals with cardiovascular and respiratory disease. Although the components of air pollution that cause the adverse health effects in these individuals are unknown, a small proportion by mass but a large proportion by number of the ambient air particles are ultrafine, i.e., less than 100 nm in diamete...

Vehicle exhaust is rich in polycyclic aromatic hydrocarbons (PAH) and can be a dominant contributor to ultrafine urban particulate matter (PM). Exposure to ultrafine PM is correlated with respiratory infections and asthmatic symptoms in young children. The lung undergoes substantial growth, alveolarization, and cellular maturation within the first years of life, which may be impacted by environ...

BACKGROUND The potential impact of municipal solid waste incineration (MSWI), which is an anthropogenic source of aerosol emissions, is of great public health concern. This study investigated the characterization and cytotoxic effects of ambient ultrafine particles (PM<0.2), fine particles (PM0.2-2.5) and coarse particles (PM2.5-10) collected around a municipal solid waste incineration (MSWI) p...

Various noncanonical sentence constructions are derived from basic sentence structures by a phrase displacement called Movement. The moved phrase (filler) leaves a silent copy at the extracted position (gap) and is reactivated when the hearer/reader passes over the gap. Consequently, memory operations are assumed to occur to establish the filler-gap link. For languages that have a relatively fr...

A new scheme of detecting fillers in spontaneous speech recognition process was developed. When a filler hypothesis appears during the 2 pass decoding of a speech recognizer with two-pass configuration, a prosodic module checks the morpheme which is hypothesized as a filler and outputs the likelihood score of the morpheme being a filler. When the likelihood score exceeds a threshold, a prosodic...

In hybrid laser–MIG keyhole welding, anti-crack elements can be added into the weld pool through a filler metal in anticipation of compensating mass loss, preventing porosity formation and improving compositional and mechanical properties of the welds. Understanding the mixing and diffusion of the filler metal in the molten pool is vital to achieve these desired objectives. In this study, mathe...