BACKGROUND Industrial-scale biocatalytic synthesis of fine chemicals occurs preferentially as continuous processes employing immobilized enzymes on insoluble porous carriers. Diffusional effects in these systems often create substrate and product concentration gradients between bulk liquid and the carrier. Moreover, some widely-used biotransformation processes induce changes in proton concentra...

nasal mupirocin is found to eradicate effectively methicillin-resistant staphylococcus aureus (mrsa) from colonized patients, but there are concerns about resistant strains. the aim of this study was to detect the mupirocin resistance and nasal carriage of methicillin resistant s. aureus among healthcare workers (hcws) at the university hospitals of tehran.totally 270 nasal swabs were collected...

ABSTRACT In this paper I summarize our recent investigations (Park and Kim, Phys Chem C 111:14903, 2007; Solid State Ionics 179:1329, 2008) on the origin of the grain-boundary resistance in a doped LaGaO3, a perovskite-structured solid electrolyte. The partial electronic and ionic resistances of the bulk and the grain boundaries, as well as the total resistance, in 1 mol% Sr-doped LaGaO3 were m...

Ultrafast laser-induced demagnetization of Gd(0001) has been investigated by magneto-induced optical second harmonic generation and the magneto-optical Kerr effect which facilitate a comparison of surface and bulk dynamics. We observe pronounced differences in the transient changes of the surface and bulk sensitive magneto-optical signals which we attribute to transfer of optically excited, spi...

The interplay between spin and charge transport in electrically and magnetically inhomogeneous semiconductor systems is investigated theoretically. In particular, the theory of spin-polarized bipolar transport in magnetic p-n junctions is formulated, generalizing the classic Shockley model. The theory assumes that in the depletion layer the nonequilibrium chemical potentials of spin-up and spin...

A large number of half-Heusler compounds have been recently proposed as three-dimensional (3D) topological insulators (TIs) with tunable physical properties. However, no transport measurements associated with the topological surface states have been observed in these half-Heusler candidates due to the dominating contribution from bulk electrical conductance. Here we show that, by reducing the m...

The bulk carrier excitation influences the phonon dynamics, which can alter and modulate surface charge density of topological insulators such as bismuth selenide (Bi2Se3). This work investigates dynamics in Bi2Se3 grown on various substrates. orientation substrate, size crystallites, misfit lattice affect dynamics. thin films are under same growth conditions SiO2, Si(111), SiN. overlayers exhi...

Carriers of certain human leukocyte antigen class I alleles show favorable prognosis of human immunodeficiency virus type 1 (HIV-1) infection, presumably due to effective CD8(+) cytotoxic T-lymphocyte responses, but close relationships between class I variants mediating such responses to natural and to vaccine HIV-1 antigen have not been established. During 6 to 30 months of administration and ...