Abnormalities of CD45 isoform expression in HIV infection

Systemic chemotherapy with 5-fluorouracil (5-FU) has been the mainstay of treatment for patients with metastatic colorectal carcinoma. Administering the drug in a continuous low-dose schedule has produced better result than bolus therapy. Resistance to short-pulse treatment can also be overcome by prolonged exposure. Recent studies suggest the feasibility of biomodulation of 5-FU with recombinant interferon (rIFN alpha-2a) with improved response. Sixteen patients were treated with continuous 5-FU 250 mg/m2 and rIFN alpha-2a 10 x 10(6) u thrice weekly for a maximum of 24 weeks. Five of them had received bolus 5-FU previously. Nine (82%) of the chemonaive group and 1 (20%) previously treated patient had partial response. The median duration of response was 7 months. Grade II to III mucositis were seen in 44% of the patients and 2 patients developed neurological complications. Although the overall response appeared encouraging, the incidence of toxicity was high. In the absence of further phase III studies, rIFN alpha-2a biomodulation of 5-FU cannot be regarded as standard treatment for patients with metastatic colorectal carcinoma.     

Reliability of a 2-Unit Standby Redundant System with Repair, Maintenance and Standby Failure

A repairable 2-unit warm-standby system with repair and preventive maintenance is discussed. Two models are presented. In each of the models the mean time to system failure and the steady state availability are calculated. Some numerical calculations illustrate the results.     

Investigation of monolayer roughness in HgTe-CdTe superlattices

Infrared photoluminescence (PL) measurements were performed on (2ID-oriented superlattices with energy gaps in the range 110–495 meV. Most of the samples with thinner HgTe quantum wells displayed two PL peaks separated by Δhω ≈ 30–65 meV (which generally increased with decreasing well thickness). Both peak energies (E_p) sometimes varied gradually with location on the surface, and in one case three peaks of approximately equal spacing were observed in some locations. The data are consistent with a model which assumes the presence of randomly distributed islands having well thicknesses varying by approximately one monolayer. We find that Ahco and the variations of the spectra with temperature agree well with calculations based on this simple model.     

Solar hydrogen generation from organic substance using earth abundant CuS–NiO heterojunction semiconductor photocatalyst

This work explores the critical role of NiO co-catalyst assembled on the surface of a CuS primary photocatalyst which effectively improves interface properties and enhances solar-to-hydrogen production by prolonging lifetime of photo-excitons generated at the CuS surface. The nanoscale CuS/NiO heterojunction is formulated using hydrothermal and wet impregnation methods. The resultant CuS/NiO composite shows optical absorbance between 380 and 780 nm region. The type-II energetic structure formed at CuS/NiO heterojunction facilitates rapid charge separation and as a result, the CuS/NiO composite exhibits 13 folds higher photocatalytic water splitting performance than CuO and NiO. The champion CuO/NiO photocatalyst is first identified by screening the catalysts using a preliminary water splitting test reaction under natural Sunlight irradiation. After the optimization of the catalyst, it was further explored for enhanced photocatalytic hydrogen production using different organic substances dispersed in water (alcohols, amine and organic acids). The champion CuS/NiO catalyst (CPN-2) exhibited the photocatalytic hydrogen production rate of 52.3 mmol h^?1.g^?1_cat in the presence of lactic acid-based aqueous electrolyte and, it is superior than hydrogen production rate obtained in the presence of other organic substances (triethanolamine, glycerol, ethylene glycol, methanol) tested under identical experimental conditions. These results indicate that the energetic structure of CuS/NiO photocatalyst is favorable for photocatalytic oxidation or reforming of lactic acid. The oxidation of lactic acid contributes both protons and electrons for enhanced hydrogen generation as well as protects CuS from photocorrosion. The modification of surface property and energetic structure of CuS photocatalyst by the NiO co-catalyst improves photogenerated charge carrier separation and in turn enhances the solar-to-hydrogen generation efficiency. The recyclability tests showed the potential of CPN-2 photocatalyst for prolonged photocatalytic hydrogen production while continuous supply of lactic acid feedstock is available.     

Effect of particle size on lignite devolatilization in a fixed-bed reactor

A fixed-bed coal gasification reactor was set up which specifically simulated the devolatilization zone in a gasifier. Samples (100 g) of lignite coal in three size ranges; ?2+1 mm, ?3+2 mm and ?4+3 mm, were devolatilized in the temperature range 350–550 °C with a steam-oxygen mixture, at 1 atm. The effect of these operating variables on tar yield and composition, melting point, viscosity, specific gravity, and molecular weight distribution was determined. A first-order reaction model was fitted to the experimentally observed total loss in weight of the lignite.     

Electrochemical synthesis and characterization of CdSnSe thin films

The effects of deposition potentials on the electrochemical, structural, morphological and optical properties of the CdSnSe films are studied. X-ray diffraction patterns revealed a mix of cubic and orthogonal phases for the grown CdSnSe thin films. The refractive index, extinction coefficient, dielectric constant and thereby the optical band gap of the films are calculated from transmittance spectral data recorded in the range 400–1,200 nm by UV–Vis–NIR Spectrometer. The optical band gap energy of CdSnSe thin films is found to be in the range of 1.23–1.25 eV. Morphological studies revealed nano-rod shaped grains occupied over the entire surface of the film with average grain size of 150 nm. The influence of deposition potential on the microstructural properties of CdSnSe is also explained in the paper.     

Creating Three-Dimensional Models to Investigate Brittle Fracture in Polycrystalline Metals

Three-dimensional models with irregular grain geometries and appropriate physical properties are needed to investigate fracture in polycrystalline metals and alloys. Creating such models is challenging but achievable using a two-stage process, suitable for any polycrystal. The processes described in this paper are illustrated by examples of brittle fracture in ferritic steel, zinc and nickel. The predicted crack path in a model is compared with the grain boundary fracture seen in three point bend specimens of nickel embrittled by sulphur.     

Hidden possibilities in soliton switching through tunneling in erbium doped birefringence fiber with higher order effects

In this paper, coupled higher order nonlinear Schrödinger–Maxwell–Bloch equations are studied for the ultrashort pulse propagation in erbium-doped birefringent fiber system. Lax pair is constructed for the CHNLS–MB system. Through the Darboux method and symbolic computation, analytic two-soliton solution is obtained. To analyze the specific problem, we design an optimal system by properly choosing the special form of variable coefficients. Here, using obtained two-soliton solution, tunneling of femtosecond soliton through barrier and well is investigated. While solitons are passing through barrier and well, some unexpected behavior is observed and hidden possibilities in switching action through tunneling is investigated.