Sieving of aerosol particles with metal screens

Metal screens with uniform micrometer-sized opening were employed to sieve aerosol particles by suppressing the adhesion of particles smaller than the openings. The collection efficiencies of monodispersed polystyrene latex (PSL) particles were experimentally determined using the metal screens with 1.2, 1.8, 2.5, and 4.2 μm openings at various filtration velocities. The particles smaller than the mesh opening adhered on the metal screen at a low filtration velocity, but the bounce-off of particles on the mesh surface suppressed the adhesion at a high velocity. As a result, we found that the adhesion of PSL particles larger than 0.3 μm mostly suppressed at a filtration velocity higher than 10 m s−1 and therefore we can sieve aerosol particles according to the opening size of metal screens. We also found that the particle number concentration could be determined by measuring the increase in pressure drop since the clogging of metal screen openings takes place by the individual particles. © 2016 American Association for Aerosol Research © 2016 American Association for Aerosol Research.Embargo Period 12 month

Prognosis of Japanese patients with previously untreated metastatic renal cell carcinoma in the era of molecular-targeted therapy

A multicenter cooperative study was conducted to clarify the prognosis of Japanese patients with metastatic renal cell carcinoma in the era of molecular-targeted therapy and the clinical usefulness of the Japanese metastatic renal cancer (JMRC) prognostic classification. Of 389 consecutive patients for whom treatment was started between 2008 and 2010 at 23 hospitals in Japan, 357 patients who received vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFR-TKI) or cytokine as initial systemic therapy were the subject of the present study. Patients were classified into three prognostic groups according to the JMRC prognostic classification. The endpoints were progression-free survival (PFS) and overall survival (OS) after the start of the initial treatment. The median PFS and OS for the entire cohort of 357 patients were 9.1 and 27.2months, respectively. VEGFR-TKI were selected for patients with multiple organ metastases, those with liver metastasis, and those with bone metastasis. The median PFS and OS were 11.0 and 23.2months and 5.4 and 38.2months in the VEGFR-TKI group and the cytokines group, respectively. The JMRC prognostic classification was useful as a prognostic model for PFS and OS (c-indexes: 0.613 and 0.630 in patients who initially received VEGFR-TKI and 0.647 and 0.642 in patients who received cytokines, respectively). The present study showed for the first time the prognosis of Japanese patients with metastatic renal cell carcinoma in the era of molecular-targeted therapy. The JMRC prognostic classification may be clinically useful as a prognostic model

Analysis of Environmental and Pathogenic Bacteria Attached to Aerosol Particles Size-Separated with a Metal Mesh Device

Metal mesh devices (MMDs) are novel materials that enable the precise separation of particles by size. Structurally, MMDs consist of a periodic arrangement of square apertures of characteristic shapes and sizes on a thin nickel membrane. The present study describes the separation of aerosol particles using palm-top-size collection devices equipped with three types of MMDs differing in pore size. Aerosols were collected at a farm located in the suburbs of Nairobi, Kenya; aerosol particles were isolated, and pathogenic bacteria were identified in this microflora by next-generation sequencing analysis. The composition of the microflora in aerosol particles was found to depend on particle size. Gene fragments were obtained from the collected aerosols by PCR using primers specific for the genus Mycobacterium. This analysis showed that Mycobacterium obuense, a non-tuberculous species of mycobacteria that causes lung diseases, was present in these aerosols. These findings showed that application of this MMD analytical protocol to aerosol particles can facilitate the investigation of airborne pathogenic bacteria