Study on a New Ultraviolet Sterilizer to the Surface Disinfection of the Ultrasound Probe.

We studied the disinfection effect of a new ultraviolet (UV) sterilizer and its utilization on ultrasound probe surfaces. Carrier quantitative germicidal tests, simulated on-the-spot trials, and organic substance influence tests were used to carry out experimental observation. Artificially infected probes were disinfected using the sterilizer or a germicidal lamp for comparison.

[Transport of PLGA nanoparticles across Caco-2/HT29-MTX co-cultured cells].

The present study is to establish Caco-2/HT29-MTX co-cultured cells and investigate the transport capability of PLGA nanoparticles with different surface chemical properties across Caco-2/HT29-MTX co-cultured cells. PLGA-NPs, mPEG-PLGA-NPs and chitosan coated PLGA-NPs were prepared by nanoprecipitation method using poly(lactic-co-glycolic acid) as carrier material with surface modified by methoxy poly(ethylene glycol) and chitosan. The particle size and zeta potential of nanoparticles were measured by dynamic light scattering.

[Transport of mPEG-PLGA nanoparticles across the rat nasal mucosa].

To investigate the effects of particle size, mPEG molecular weight, coating density and zeta potential of monomethoxyl poly(ethylene glycol)-poly(lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles on their transportation across the rat nasal mucosa, mPEG-PLGA-NPs with different mPEG molecular weights (M(r) 1 000, 2 000) and coating density (0, 5%, 10%, 15%) and chitosan coated PLGA-NP, which loaded coumarin-6 as fluorescent marker, were prepared with the nanoprecipitation method and emulsion-solvent evaporation method, and determine their particle size, zeta potential, the efficiency of fluorescent labeling, in vitro leakage rate and the stability with the lysozyme were determined. The effects of physical and chemical properties on the transmucosal transport of the fluorescent nanoparticles were investigated by confocal laser scanning microscopy (CLSM). The result showed that the size of nanoparticles prepared with nanoprecipitation method varied between 120 and 200 nm; the size of nanoparticles prepared with emulsion-solvent evaporation method varied between 420 and 450 nm.

[Epidemiological study of the transmission chain of a severe acute respiratory syndrome outbreak].

Objective: To investigate the process of SARS transmission and to evaluate infectivity of SARS patients in different periods of disease development.

Methods: A case of SARS outbreak beginning from a male, 74-year-old patient in Beijing. Two hundred and seventy five primary, secondary and tertiary contacts, including family members relatives, colleagues, and others exposed to him, were traced by field investigation and telephone interview using a standardized questionnaire.