STUDY OBJECTIVES To document the current practice of occupational asthma (OA) diagnosis and use of specific inhalation challenge (SIC). DESIGN, SETTING, AND PARTICIPANTS A survey evaluating the current practice of SIC was mailed to 259 residency training programs in adult pulmonary diseases, allergy and immunology, and occupational medicine accredited in the United States and Canada during th...

Streptococcal inhibitor of complement (SIC) is a highly polymorphic extracellular protein and putative virulence factor secreted by M1 and M57 strains of group A Streptococcus (GAS). The sic gene is highly upregulated in invasive M1T1 GAS isolates following selection of mutations in the covR/S regulatory locus in vivo. Previous work has shown that SIC (allelic form 1.01) binds to and inactivate...

Dense silicon carbide (SiC) matrix composites with SiC whiskers and particles as reinforcement were prepared by infiltrating molten Si at 1550 °C into porous preforms composed of pyrolysed rice husks (RHs) and extra added SiC powder in different ratios. The Vickers hardness of the composites showed an increase from 18.6 to 21.3 GPa when the amount of SiC added in the preforms was 20% (w/w), and...

Different polytypes (α-SiC and β-SiC) and crystallographic orientations ((0001) and (11-20) of 6H-SiC) have been used in order to elaborate Silicon Carbide (SiC) nanopillars using inductively coupled plasma etching method. The cross section of the SiC pillars shows a rhombus, pentagon, or hexagonal morphology depending on polytypes and crystallographic orientations. The favored morphologies of ...

The cluster-expansion method was used to perform first principles phase diagram calculations for the wurtzite-structure quasibinary systems (SiC)1 X(AlN)X, (SiC)1 X (GaN)X and (SiC)1 X(InN)X; and to model variations of band gaps as functions of bulk compositions and temperature. In SiC-AlN, plane wave pseudopotential formation-energy calculations predict low-energy metastable states with format...

SiC-SiC composites offer excellent potential for fusion energy as well as numerous commercial applications. High manufacturing cost and very low through-the-thickness (transverse) thermal conductivity (below 15 W/mK) hinders wider applications of SiC/SiC composites. To overcome these obstacles, a low-cost, Chemical Vapor Reaction (CVR) process was developed to fabricate crystalline, high purity...

In this paper, the comparison of cyclic hysteresis behavior between cross-ply C/SiC and SiC/SiC ceramic-matrix composites (CMCs) has been investigated. The interface slip between fibers and the matrix existed in the matrix cracking mode 3 and mode 5, in which matrix cracking and interface debonding occurred in the 0° plies are considered as the major reason for hysteresis loops of cross-ply CMC...