2,923 research outputs found
A practical approach to managing patients with HCV infection.
Hepatitis C virus (HCV) infection is a major worldwide public health concern. It is a common cause of chronic liver disease and hepatocellular carcinoma. HCV antibody and HCV RNA testing are available diagnostic studies that offer high degree of accuracy. Current standard therapy includes a combination of pegylated interferon and ribavirin. Response rate is approximately 40% for genotype 1 and 80% for genotypes 2 and 3, respectively. Successful treatment can stop the progression of chronic liver disease, reduce the need for liver transplantation, and possibly decrease the risk for Hepatocellular carcinoma (HCC). Evaluating for potential treatment candidacy is an important initial step in the management of chronic HCV infection as not all individuals may need or qualify for the treatment. Understanding the natural history, the different diagnostic modalities, the current therapeutic options and, the treatment response and adverse effect profiles can help the practitioners better manage chronic HCV infection
Analytical treatment of cold field electron emission from a nanowall emitter
This paper presents an elementary, approximate analytical treatment of cold
field electron emission (CFE) from a classical nanowall. A simple model is used
to bring out some of the basic physics of a class of field emitter where
quantum confinement effects exist transverse to the emitting direction. A
high-level methodology is presented for developing CFE equations more general
than the usual Fowler-Nordheim-type (FN-type) equations, and is applied to the
classical nanowall. If the nanowall is sufficiently thin, then significant
transverse-energy quantization effects occur, and affect the overall form of
theoretical CFE equations; also, the tunnelling barrier shape exhibits
"fall-off" in the local field value with distance from the surface. A conformal
transformation technique is used to derive an analytical expression for the
on-axis tunnelling probability.Comment: 48 pages, 4 figure
A Statistical Model of Pressure Drop Increase with Deposition in Granular Filters
As deposits accumulate in a granular filter, pressure drop across the filter
bed required to maintain a constant fluid flow rate may increase. Two pressure
drop increase patterns had been observed. In slow sand filters pressure drop
remains unchanged for a certain period of time then increases exponentially
with the volume of filtrate; in granular aerosol filters pressure drop
increases linearly with the amount of deposits from the beginning of the
filtration process. New concepts of homogeneous and heterogeneous depositions
were introduced in this paper. A statistical model based on these new concepts
was developed. This non-linear model was able to reproduce both observed
pressure drop increase patterns, including the linear one. Excellent agreements
between the present model and experimental measurements were obtained. It was
concluded that the two pressure drop increase patterns were indeed caused by
different deposit distributions rather than different pressure drop increase
mechanisms.Comment: 14 pages, 9 figure
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Mesoscale modelling of miscible and immiscible multicomponent fluids
A mesoscopic simulation method based on the integration of dissipative particle dynamics (DPD), smoothed particle hydrodynamics (SPH) and computational thermodynamics (CT) has been developed. The kinetic behaviours of miscible and immiscible fluids were investigated. The interaction force between multicomponent mesoscopic particles is derived from the system free energy. The diffusivity of the components in non-ideal solution is determined by the chemical potential. The proposed method provides convincing predictions to the effects of convection, diffusion and microscopic interaction on the non-equilibrium evolution of engineering fluids, and demonstrates a potential to simulate more complicated phenomena in materials processing
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