Comparison of alkylglycoside surfactants in enantioseparation by capillary electrophoresis

We examined the biopsy specimens of 62 patients with diabetic nephropathy to establish whether the myofibroblast (MF) has a role in progressive interstitial fibrosis and to ascertain whether a relationship existed between MF activity and severity of arteriolosclerosis. MF were identified by morphology and alpha smooth muscle actin (alpha SMA) immunostaining. Analysis of vascular injury was performed by counting the number of interstitial arterioles after staining endothelial cells with von Willebrand factor (VWF) antibody. Arteriosclerosis was quantified by using a computer-aided image analyzer to measure the arteriolar wall surface and total arteriolar surface area, and the ratio of wall to total surface area was expressed as the index of arteriosclerosis (IA). Fractional area of interstitium (IFA), alpha SMA, and collagen III (Coll III) were quantitated by point counting. Results were related to structural and functional parameters using rank correlation coefficients. There was a strong correlation between IFA and Coll III staining (r = 0.83; P < 0.001). The alpha SMA staining correlated with IFA (r = 0.56; P < 0.001) and Coll III (r = 0.47; P < 0.001), and there were significant correlations between alpha SMA and total urinary protein (r = 0.47; P < 0.001), renal function (plasma creatinine) at time of biopsy (r = 0.51; P < 0.001), and the percent change in plasma creatinine after 4 years (delta Cr) (r = 0.37; P = 0.01). The IA correlated significantly with Coll III (r = 0.29; P = 0.02), glomerular filtration rate (GFR) (r = 0.39; P = 0.008), and creatinine (r = 0.33; P = 0.01), but no correlation was observed between alpha SMA and IA (r = 0.16; P = 0.23) or IA and delta Cr (r = -0.04; P = 0.6). Strong correlations could be shown between arteriolar density, IFA (r = 0.75; P < 0.001), alpha SMA (r = -0.36; P = 0.034), and Coll III (r = -0.66; P < 0.0001). The MF appears to have a significant role in the progression of diabetic nephropathy. Ischemia secondary to arteriosclerosis may contribute to interstitial fibrosis through fibroblast modulation into MF.     

Mathematical modeling of falling liquid film evaporation process

A mathematical model of evaporation process from a laminar falling liquid film on a vertical plate of constant temperature is presented. The model is developed with and without interfacial shear stress due to the vapor flow at the liquid film surface. The vapor pressure drop, vapor exit velocity and cooling rate are calculated for different liquid mass flow values. It is shown that lower liquid mass flow produces higher cooling rate. The results also show that the interfacial shear stress has a considerable negative effect on the cooling rate. It is proved that there exists an optimum distance between the plates, which gives the maximum volumetric cooling rate.     

A bidding decision index for construction contractors

Results from applying the model on a sample of contractors, the majority of whom were international and operating in Egypt, reinforces the credibility of the developed methodology, claim the authors.     

Sensitivity analysis of the scattering parameters of microwave filters using the adjoint network method

A novel approach is presented to calculate the sensitivities of the scattering parameters of microwave filters obtained with the full‐wave mode‐matching (MM) technique. Using only the MM simulation of the original network, the sensitivities of the scattering parameters with respect to all designable parameters are obtained. The adjoint network method (ANM) is applied to the generalized scattering matrices of the different filter components. This guarantees good accuracy of the calculated sensitivities. The implementation details are discussed for N‐resonator ridge waveguide filters. Excellent agreement is obtained between the sensitivities calculated using ANM and those obtained using the expensive central differences. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.     

Oil Families and Their Potential Sources in the Southern Gulf of Suez, Egypt

Four oil families are identified in the southern Gulf of Suez, through high-resolution geochemical studies including gas chromatography, gas chromatography-mass spectrometry, and carbon isotope analyses. Biological features characterize oils in family 1a, suggesting tertiary carbonate source rocks for these oils, rich in type II organic matter and deposited under anoxic depositional environment. Family 1b oil shows minor variations in the source of organic matter and the depositional environment, as it was derived from carbonate source rock with more algal and bacterial contribution and minor input of terrestrial organic sources, deposited under less saline condition compared to family 1a oil. Family 2 oil, although genetically related to family 1a oil, has some distinctive features, such as diasterane to sterane and pristane to phytane ratios, which suggest clay-rich source rocks and a more oxic depositional environment. Also, the lack of oleanane indicates pre-tertiary source rocks for this oil. In contrast, family 3 oil is of mixed sources (marine and non-marine), generated from low sulfur and clay-rich source rock of tertiary and/or younger age. Family 4 oil seems to be mixed from family 1b and family 3 oils, sourced mainly from carbonate source rocks rich in clay minerals with algal and bacterial contributions. Family 4 oil is highly mature, family 1b oil lies within equilibrium values (peak oil generation stage), while the other families are more or less near equilibrium.     

Catalytic properties of composite amorphous carbon-platinum layers in fuel cells

Catalytic properties of composite amorphous carbon-platinum layers produced by magnetron cosputtering have been studied. The layers were characterized by electron microscopy, IR spectroscopy, ellipsometry, gravimetry, and spectrophotometric chemical analysis. The catalytic activity of the layers was studied in an air-hydrogen fuel cell by measuring its load and power characteristics.     

Model for Nanoscopic Domain Formation in Dipalmitoyl-PC/Dilauroyl-PC/Cholesterol Mixture

We describe the lyotropic liquid crystalline phase transitions in the lipid mixture dipalmitoil-PC/dilauroy-PC/cholesterol by 3D spin-1 lattice model. The formation of nanoscale domains with the characteristic size about 300 nm was studied in experiments on confocal fluorescence microscopy (CFM) (G. V. Feigenson and J. T. Buboltz, Biophys. J. 80, 2775 (2001)). The structure parameters of the lamellar vesicle in dipalmitoil-PC-rich phase, corresponding to these regions, are verified by numerical Monte Carlo simulations on the lattice. We point its superconductivity analogy properties at the region of phase stability for composition-dependent nanoscopic region.     

Corrosion of tin in citric acid solution and the effect of some inorganic anions

The corrosion behaviour of tin in different concentrations of citric acid solutions (0.3–1.0 M, pH=1.8) was studied at 30 °C by potentiodynamic technique. The E/I profiles exhibit an active passive behaviour. The active dissolution involves one anodic peak A associated with a dissolution of the metals as Sn(II) species. The passivity is due to the formation of thin film of SnO₂ and or Sn(OH)₄ on the anode surface. The cathodic sweep shows a small peak C related to the reduction of the passive film. The peak current density I_p of peak A increases with increasing both acid concentration and sweep rate.

The effects of adding increasing concentrations of Na₂CrO₄, NaMoO₄, NaNO₃ and NaNO₂ on the corrosion of tin in 0.5 M citric acid at 30 °C were investigated. Both CrO₄²⁻ and MoO₄²⁻ ions inhibit the corrosion of tin and the extent of inhibition enhances with their concentrations. Addition of either NO₃⁻ or NO₂⁻ accelerates the corrosion of tin. NO₃⁻ ions are more aggressive than NO₂⁻ ions.