Comparative Analysis of the Antiviral Activity of Camel,Bovine, and Human Lactoperoxidases Against Herpes Simplex Virus Type 1

Lactoperoxidase is a milk hemoprotein that acts as a non-immunoglobulin protective protein and shows strong antimicrobial activity. Bovine milk contains about 15 and 7 times higher levels of lactoperoxidase than human colustrum and camel milk, respectively. Human, bovine, and camel lactoperoxidases (hLPO, bLPO, and cLPO, respectively) were purified as homogeneous samples with specific activities of 4.2, 61.3, and 8.7 u/mg, respectively. The optimal working pH was 7.5 (hLPO and bLPO) and 6.5 (cLPO), whereas the optimal working temperature for these proteins was 40 °C. The K _m of hLPO, cLPO, and bLPO were 17, 16, and 19 mM, and their corresponding V _max values were 2, 1.7, and 2.7 μmol/min ml. However, in the presence of H₂O₂, the K _m values were 11 mM for hLPO and cLPO and 20 mM for bLPO, while the corresponding V _max values were 1.17 for hLPO and 1.4 μmol/min ml for cLPO and bLPO. All three proteins were able to inhibit the herpes simplex virus type 1 (HSV-1) in Vero cell line model. The relative antiviral activities were proportional to the protein concentrations. The highest anti-HSV-1 activity was exhibited by bLPO that inhibited the HSV particles at a concentration of 0.5 mg/ml with the relative activity of 100%.

     

Numerical simulation of melting ice around a floating by microwaves

In this paper a new method in using microwaves is provided for melting the ice around a floating equipment in a freezing condition in cold regions. The numerical simulation’s results for validation are compared with the simple model’s experimental data. Using microwave in melting the ice around a floating equipment is caused by lack of the mechanical wear, low energy dissipation factor and acceptable defrosting process speed in small lakes.     

Heat transfer from extended surfaces subject to variable heat transfer coefficient

The present article investigates the effect of locally variable heat transfer coefficient on the performance of extended surfaces (fins) subject to natural convection. Fins of different profiles have been investigated. The fin profiles presently considered are namely; straight and pin fin with rectangular (constant diameter), convex parabolic, triangular (conical) and concave parabolic profiles and radial fins with constant profile with different radius ratios. The local heat transfer coefficient was considered as function of the local temperature and has been obtained using the available correlations of natural convection for each pertinent extended surface considered. The performance of the fin has been expressed in terms of the fin efficiency. Comparisons between the present results for all fins considered and the results obtained for the corresponding fins subject to constant heat transfer coefficient along the fin are presented. Comparisons, i.e. showed an excellent agreement with the experimental results available in the literature. Results show that there is a considerable deviation between the fin efficiency calculated based on constant heat transfer coefficient and that calculated based on variable heat transfer coefficient and this deviation increases with the dimensionless parameter m.     

ZrOCl2 · 8H2O as an Efficient Reagent for the Solvent‐Free Synthesis of 3,4‐Dihydropyrimidin‐2‐(1H)‐ones

ZrOCl₂ · 8H₂O, a commercially available reagent, can be used for the promotion of the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones under solvent‐free reaction conditions. All reactions were performed at 90°C in good to high yields.     

Application of the β-cyclodextrin supramolecules as a green accelerator hosts in one-step preparation of highly functionalised rhodanine scaffolds

β-Cyclodextrin (β-CD) supramolecule was found to be a convenient, green and economical tool in one-pot synthesis of rhodanine scaffolds as a highly efficient mediating agent in aqueous media in which the reaction accelerated to complete in 15 min and room temperature. In this work, amines reacted with equimolar ratio of CS₂ (not excess ratio of CS₂) and then with activated acetylenes in the presence of β-CD in aqueous media.     

Using graphene/TiO2 nanocomposite as a new route for preparation of electroconductive,self-cleaning,antibacterial and antifungal cotton fabric without toxicity

A novel and efficient process is reported for fabrication of electroconductive, self-cleaning, antibacterial and antifungal cellulose textiles using a graphene/titanium dioxide nanocomposite. Cotton fabric was loaded with graphene oxide using a simple dipping coating method. The graphene oxide-coated cotton fabrics were then immersed in TiCl₃ aqueous solution as both a reducing agent and a precursor to yield a fabric coated with graphene/titanium dioxide nanocomposite. The crystal phase, morphology, microstructure and other physicochemical properties of the as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-Vis reflectance spectroscopy. Electrical resistance, self-cleaning performance, antimicrobial activity and cytotoxicity of treated fabrics were also assessed. The electrical conductivity of the graphene/titanium dioxide nanocomposite-coated fabrics was improved significantly by the presence of graphene on the surface of cotton fabrics. The self-cleaning efficiency of the treated fabrics was tested by degradation of methylene blue in aqueous solution under UV and sunlight irradiations. The results indicated that the decomposition rates of methylene blue were improved by the addition of graphene to the TiO₂ treatment on fabrics. Moreover, the graphene/titanium dioxide nanocomposite-coated cotton samples had negligible toxicity and possessed excellent antimicrobial activity.     

Electrochemical Oxidation of Iodide in the Presence of Benzenesulfinic Acids and Its Application to the Quasi-Catalytic Determination of Benzenesulfinic Acids

The mechanism of the electrochemical oxidation of iodide in the presence of 4-toluenesulfinic acid was studied in an aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that the anodically generated iodine reacts with 4-toluenesulfinic acid through a quasi-catalytic process. In addition, the results indicate the suitability of iodide as a mediator for the determination of 4-toluene-sulfinic acid in aqueous solutions. The quasi-catalytic peak currents are linearly dependent on the 4-toluene-sulfinic acid concentrations in the range 6.0 ×10⁻³ − 8.0 × 10⁻⁶ M.__________From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 6, 2005, pp. 598–602.Original English Text Copyright © 2005 by Davood Nematollahi, Zinat Forooghi, Esmail Tammari.This article was submitted by the authors in English.     

Viscous dissipation of Rankine vortex profile in zero meridional flow

An analytical solution is given for a time-decay Rankine vortex profile due to viscous effects. The vortex filament is assumed to be isolated, strong, concentrated and having zero-meridional flow (i.e. radial and axial velocities are equal to zero). Zero-meridional renders the governing equations for an unsteady, incompressible and axisymmetric vortex in a simple form. Based on the tangential momentum equation, the spatial-temporal distributions of the swirl velocity are given in terms of Fourier-Bessel series by using separation of variables technique. A general formula is derived by total differentiation of the swirl velocity with respect to time, depicting the viscous dissipation for Oseen and Taylor-like vortex profiles. This analysis is validated by comparison with previous experimental data.     

Effect of gamma-irradiation on surface and catalytic properties of nanocrystalline CuO,NiO and Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> supported on alumina

The effect of γ-irradiation on surface and catalytic properties of CuO/Al₂O₃, NiO/Al₂O₃ and Fe₂O₃/Al₂O₃ was investigated. The techniques employed were XRD, nitrogen adsorption at −196 °C and catalytic conversion of ethanol and isopropanol at 250–400 °C using micropulse technique. The results showed that the supported solids being calcined at 400 °C consisted of well crystallized CuO, NiO, Fe₂O₃ and AlOOH phases. The AlOOH crystallized into a poorly crystalline γ-Al₂O₃ upon heating at 600 °C. All phases present in different solids calcined at 400 and 600 °C showed that these solids are of nanocrystalline nature measuring an average crystallite size between 6 and 85 nm. The crystallite size of crystalline phases present was found to be much affected by the dose of γ-rays and the nature of the metal oxide. This treatment resulted in a progressive increase in the specific surface area reaching to a maximum limit at a dose of 0.8 MGy. The dose of 1.6 MGy exerted a measurable decrease in the S _BET. A radiation dose of 0.2 to 0.8 MGy brought about a progressive significant decrease in the catalytic activity of all the catalytic systems investigated. All the catalytic systems retained their high activity upon exposure to a dose of 1.6 MGy. The rise in precalcination temperature of the systems investigated from 400 to 600 °C brought about a measurable increase in their catalytic activity in the conversion of alcohols.