Size dependent interaction of biofunctionalized CdS nanoparticles with tyrosine at different pH

Enhancement of fluorescence of CdS nanoparticles by tyrosine at pH 10 in contrast to Stern-Volmer quenching at pH 7 was observed and both the effects were found to depend on the size of the nanoparticles.     

β-Alkoxycarbonyl Alkyl Tin Chelates 2. Dithizonates – Preparation and Spectroscopic Studies

Dithizone forms stable complexes with β-alkoxycarbonyl ethyl tin chlorides (the so called “Estertins” – a unique class of PVC stabilizer). Reduction of Lewis acidity of the resulting organotin chloride can improve the efficiency of a stabilizer and therefore the β-alkoxycarbonyl ethyl tin dithizonates are likely to show PVC stabilization property. A number of β-alkoxycarbonyl ethyl tin dithizonates of the types R₂SnL₂, R₂SnLX, and RSnL₂X where R = CH₃OCOCH₂CH₂–, C₄H₉OCOCH₂CH₂–, and CH₃OCOCH(CH₃)CH₂–; X = Cl, SCN and L = Dithizone (i. e. 1,5-diphenyl thiocarbazone) and one complex (CH₃OCOCH₂CH₂)₂SnL′Cl where L′ = Diphenylcarbazone have been prepared and characterized by elemental analysis, electronic, IR and PMR spectral data. Possible structural features of the isolated complexes have also been discussed. Preliminary evaluation of the complex (CH₃OCOCH₂CH₂)₂Sn(HDz)₂ as a PVC stabilizer has also been reported.     

Fluoroberyllates in chemical analysis

Barium can be precipitated as barium fluoroberyllate, Ba[BeF₄], with ammonium fluoroberyllate in the presence of ethylenediaminetetraacetic acid at pH 6–7. Lead does not precipitate under these conditions and a good separation can be effected. The precipitate is dried at 110° C and weighed.     

Novel syntheses of 3-cyano-3,4-dihydroquinolin-2(1H)-one and derivatives of 2,3-dicarbomethoxy-2-hydroxycyclopenta[b]quinoline

A facile solid phase conversion of 2-chloro-3-cyano-4-substituted-1,4-dihydroquinolines to 3-cyano-4-substituted-3,4-dihydroquinolin-2(1H)-ones in almost quantitative yields and a novel synthesis of 2,3-dicarbomethoxy-2-hydroxycyclopenta[b]quinoline are described.     

Inclusion complexes of cyclodextrins with hydrophobic ionic liquids

Two imidazolium-based hexafluorophosphate ionic liquids (ILs), 1-butyl-3-methylimidazolium hexafluorophosphate and 1-dodecyl-3-methylimidazolium hexafluorophosphate, were used to form inclusion complexes (ICs) with α- and β-cyclodextrins (CDs). Formation of the ICs of each CD with each IL was confirmed by the appearance of a characteristic peak in the UV region. Characterisation of the ICs by NMR and FT-IR spectroscopy provided information about the interactions between the host and guest molecules and the structure of the ICs. Temperature-dependent particle size analysis by dynamic light scattering suggested that the size of the host and the guest governs their stability.     

A (2+1)-dimensional combined KdV–mKdV equation: integrability,stability analysis and soliton solutions

Nonlinear Dynamics - In this study, the (2+1)-dimensional combined Korteweg–de Vries and modified Korteweg–de Vries equation has been considered for the first time. Firstly, we check...     

Higher order fully discrete scheme combined withH 1-Galerkin mixed finite element method for semilinear reaction-diffusion equations

We first apply a first order splitting to a semilinear reaction-diffusion equation and then discretize the resulting system by anH ¹-Galerkin mixed finite element method in space. This semidiscrete method yields a system of differential algebraic equations (DAEs) ofindex one. Apriori error estimates for semidiscrete scheme are derived for both differential as well as algebraic components. For fully discretization, an implicit Runge-Kutta (IRK) methods is applied to the temporal direction and the error estimates are discussed for both components. Finally, we conclude the paper with a numerical example.     

Impairing effect of fibrinogen on the mono-/bi-layer form of bovine lung surfactant

Lung surfactant (LS), a lipid–protein mixture responsible for alveolar stability, is inhibited by serum proteins leaked into the lungs in disease. Interaction of bovine lipid extract surfactant (BLES), a clinical replacement lung surfactant, with serum protein fibrinogen (Fbg) was studied employing various structural and biophysical techniques in adsorbed films and bulk bilayer dispersions. Surface tension area isotherms of the adsorbed films revealed the suppression of interfacial activity of BLES by Fbg (adsorption and surface tension reduction). Fbg, predominantly associated with the fluid phase of BLES films, resulted in the aggregation of the gel lipid domains as evidenced by atomic force microscopy. BLES bilayer dispersion showed phase transition from a diffused gel to liquid–crystalline phase in the temperature range 10–35 °C as studied by differential scanning calorimetry (DSC). Fbg resulted in the shift of peak to a higher transition temperature for the maximal heat flow (T _max) of BLES dispersions. Combined Raman and FTIR spectral studies of the BLES/Fbg dispersions revealed that Fbg altered the –CH₂–, –CH₃, and –PO₄ ^? vibrational modes of the phospholipids present in BLES, suggesting the condensing and dehydrating effect of the protein on surfactant. Studies suggest that Fbg, by directly interacting with the gel lipids in LS in bulk dispersions, alter the packing of the films formed at the interface, and can be used as a specific model for lung disease.     

Components of optimal price under logit demand

Demand for durables can be modeled using a logit framework in which a customer chooses one brand from several alternatives, or buys nothing at all. In this framework, optimal prices for competing brands can be expressed as a system of non-linear equations, which, however, do not have closed form solutions. Although the optimal price can be determined by numerical search, the solution offers limited understanding of its components. In this article, we develop a linear approximation of the Nash equilibrium optimal price of a brand as its marginal cost plus a weighted sum of: (1) the inverse of the price sensitivity of the market, (2) the average value added by all brands in the market, and (3) the value advantage (or disadvantage) of the brand. The weights depend primarily upon the number of competing brands, with price insensitivity having the strongest impact, followed by value advantage of the brand, and average value added by all brands. This approximation for optimal price is found to be robust under a wide range of conditions. Additionally, we demonstrate that using the approximation results in only marginal deviation of profits from the theoretical Nash optimal.