The Polyvinylpyrrolidone (PVP) / Poly (L-lactic acid) (PLLA) ultrafine blend fibers have been prepared for the first time by electrospinning. Trichloromethane was found to be the co-solvent for electrospinning. The PVP/PLLA blend solutions in various ratios were studied for electrospinning into ultrafine fibers. The morphology of the fibers was shown by scanning electron microscope (SEM). It wa...

Many studies have reported associations between air pollution particles with an aerodynamic diameter <2.5 μm (fine particulate matter (PM)) and adverse cardiovascular effects. However, there is an increased concern that so-called ultrafine PM which comprises the smallest fraction of fine PM (aerodynamic diameter <0.1 μm) may be disproportionately toxic relative to the 0.1-2.5 μm fraction. Ultra...

Ambient air particles in the ultrafine size range (diameter < 100 nm) may contribute to the health effects of particulate matter. However, there are few data on ultrafine particle deposition during spontaneous breathing, and none in people with asthma. Sixteen subjects with mild to moderate asthma were exposed for 2 hr, by mouthpiece, to ultrafine carbon particles with a count median diameter (...

Exposure to air polluted with particles less than 2.5 micron in size is associated epidemiologically with adverse cardiopulmonary health consequences in humans. The goal of this study was to characterize human pulmonary responses to controlled experimental high-dose exposure to fine and ultrafine magnesium oxide particles. We quantified bronchoalveolar lavage (BAL) cell and cytokine concentrati...

BACKGROUND Ultrafine grinding is an environmentally friendly pretreatment that can alter the degree of polymerization, the porosity and the specific surface area of lignocellulosic biomass and can, thus, enhance cellulose hydrolysis. Enzyme adsorption onto the substrate is a prerequisite for the enzymatic hydrolysis process. Therefore, it is necessary to investigate the enzyme adsorption proper...

The conversion of magnetite to maghemite has been studied kinetically in the ultrafine particle range (77-220A) by chemical analysis. X-ray diffraction, and Mossbauer measurements. The reaction is third order. The activation temperatures are relatively low (8 250-1 1 200 K). Electron hopping in ultrafine magnetite powders is discussed on the basis of the results.

The root of Angelica gigas (Korean angelica) is traditionally used to treat women's ailments that are caused by an impairment of menstrual blood flow and cycle irregularities. This study evaluated the effect particle size of Korean angelica powder on its efficacy for treating estrogen-related symptoms of menopause. Initially, Korean angelica roots were pulverized into ultrafine powder, and oral...

BACKGROUND Airborne particles entering the respiratory tract may interact with the apical plasma membrane (APM) of epithelial cells and enter them. Differences in the entering mechanisms of fine (between 0.1 microm and 2.5 microm) and ultrafine ( <or= 0.1 microm) particles may be associated with different effects on the APM. Therefore, we studied particle-induced changes in APM surface area in ...

Centromeres are specialized chromosome domains that control chromosome segregation during mitosis, but little is known about the mechanisms underlying the maintenance of their integrity. Centromeric ultrafine anaphase bridges are physiological DNA structures thought to contain unresolved DNA catenations between the centromeres separating during anaphase. BLM and PICH helicases colocalize at the...