Novel TiO2/GO/CuFe2O4 nanocomposite: a magnetic, reusable and visible-light-driven photocatalyst for efficient photocatalytic removal of chlorinated pesticides from wastewater.

A TiO2/GO/CuFe2O4 heterostructure photocatalyst is fabricated by a simple and low-cost ball-milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light irradiation. Based on the advantages of graphene oxide, TiO2, and CuFe2O4, the nanocomposite exhibited visible light absorption, magnetic properties, and adsorption capacity. Integrated analyses using XRD, SEM, TEM, and UV-visible techniques demonstrated that the nanocomposite exhibited a well-defined crystalline phase, sizes of 10-15 nm, and evincing a visible light absorption feature with an optical bandgap energy of 2.4 eV. The photocatalytic degradations of 17 different chlorinated pesticides (persistent organic pollutants) were assayed using the prepared photocatalyst. The photocatalytic activity of the nanocomposite generated almost 96.5% photocatalytic removal efficiency of typical pesticide DDE from water under UV irradiation. The superior photocatalytic performance was exhibited by the TiO2/GO/CuFeO4 catalyst owing to its high adsorption performance and separation efficiency of photo-generated carriers. The photocatalyst was examined in 5 cycles for treating uncolored pesticides with purposeful separation using an external magnetic field.

Presence of enteric hepatitis viruses in the sewage and population of Greater Cairo.

In Egypt, the disease burden of viral hepatitis is one of the heaviest worldwide. We conducted a survey of hepatitis A virus (HAV) and hepatitis E virus (HEV) in patients and sewage in Cairo. Our data showed that HAV (genotype IB) was predominant over HEV (genotype 3) and was circulating in the population and the environment.

Evidence of emergence of new GGII.4 norovirus variants from gastroenteritis outbreak survey in France during the 2007-to-2008 and 2008-to-2009 winter seasons.

Analysis of 316 outbreaks of gastroenteritis in France from September 2007 through March 2009 showed that genogroup II.4 (GGII.4) noroviruses were predominant and mostly belonged to the 2006b variant. However, the new GGII.4 variants, variant 2008 and the newly discovered Cairo variant from the Middle East, were also detected. The epidemiological survey suggests that these new variants might become the next predominant strains.

Evidence of the co-circulation of enteric viruses in sewage and in the population of Greater Cairo.

AIMS: To characterize major enteric viruses (enterovirus, rotavirus, norovirus, astrovirus and adenovirus) in the sewage of Greater Cairo and to compare the results with clinical data collected during the same period. METHODS AND RESULTS: Seventy-two sewage samples from two waste water treatment plants were collected from April 2006 through February 2007. Enteroviruses, noroviruses (NoVs) and rotaviruses (RVs) were detected by RT-PCR in 22%, 18% and 8.3% of the samples, respectively. No adenovirus and astrovirus was detected. G2P[8], G9P[8], G1P[8], G2P[4] and rare G12 RV isolates were detected in the environment as well as a bovine RV. The environmental NoV strains mostly belonged to genogroup I (84%). Rotaviruses and some of the NoVs were similar to those found in the clinical samples at the same time. CONCLUSIONS: The comparison of environmental and clinical data suggests that similar RV and NoV isolates were circulating in the environment and in the population during the same period. SIGNIFICANCE AND IMPACT OF THE STUDY: Few studies have investigated the prevalence and the epidemiology of RVs and NoVs in Cairo. This work is the first to establish a correlation between viral gastroenteritis and the concomitant presence of enteric viruses in the environment for Greater Cairo where combined environmental and clinical surveys should help to prevent infections caused by these major pathogens.

Alginate-diltiazem hydrochloride beads: optimization of formulation factors, in vitro and in vivo availability.

Alginate beads containing diltiazem hydrochloride (DTZ) were prepared by the ionotropic gelation method. The effects of various factors (alginate concentration, additives type, calcium chloride concentration and curing time) on the efficiency of drug loading were investigated. The formulation containing a mixture of 0.8% methylcellulose (MC) and 4% alginate cured in 2% calcium chloride for 6 h was chosen as the best formula regarding the loading efficiency. The release rate of DTZ from various beads formulations was investigated. The release of drug from alginate beads followed two mechanisms; by diffusion and relaxation of the polymer at pH 1.2, whilst diffusion and erosion are at pH 6.8. The in vitro release of DTZ from MC-alginate beads showed an extended release pattern which was compared with that from commercially available sustained-release (Dilzem SR) and fast release tablets (Dilzem). Thermal analysis revealed that the drug was molecularly dispersed in the beads matrix. Although the release characteristics of DTZ from Dilzem SR and MC-alginate beads were completely different, the bioavailability of DTZ in dogs was comparable as measured by AUC, MRT and relative bioavailability. The absolute bioavailability of MC-alginate beads and Dilzem SR was 88 and 93%, respectively.

Epstein-Barr virus in head and neck squamous cell carcinoma.

We compared 50 patients with head and neck squamous cell carcinomas (cases) and 45 matched healthy controls. Biopsy specimens were taken from tumours and normal tissue of the cases and controls respectively and serial paraffin embedded sections were processed to detect Epstein-Barr (EB) viral antigen. We found EB viral proteins in 38% of cases and none in controls, which suggests a positive correlation. Serum samples were also tested for the presence of EB virus IgG by ELISA for comparison with immunohistochemical findings. Patients with positive immunohistochemical staining results had significantly higher mean antibody titres compared with those with negative results. ELISA may be useful in determining the etiology of head and neck cancers, but the results are not unequivocally reliable.

Epstein-Barr virus in head and neck squamous cell carcinoma

We compared 50 patients with head and neck squamous cell carcinomas [cases] and 45 matched healthy controls. Biopsy specimens were taken from tumours and normal tissue of the cases and controls respectively and serial paraffin embedded sections were processed to detect Epstein-Barr [EB] viral antigen. We found EB viral proteins in 38% of cases and none in controls, which suggests a positive correlation. Serum samples were also tested for the presence of EB virus IgG by ELISA for comparison with immunohistochemical findings. Patients with positive immunohistochemical staining results had significantly higher mean antibody titres compared with those with negative results. ELISA may be useful in determining the etiology of head and neck cancers, but the results are not unequivocally reliable

In vitro and in vivo evaluation of Pluronic F127-based ocular delivery system for timolol maleate.

The purpose of this study was to develop Pluronic F127 (PF127) based formulations of timolol maleate (TM) aimed at enhancing its ocular bioavailability. The effect of isotonicity agents and PF127 concentrations on the rheological properties of the prepared formulations was examined. In an attempt to reduce the concentration of PF127 without compromising the in situ gelling capabilities, various viscosity enhancing agents were added to PF127 solution containing 0.5% TM. The viscosity and the ability of PF127 gels to deliver TM, in vitro, in absence and presence of various viscosity enhancing agents were also evaluated. At the used concentration, some of the examined isotonicity agents had effect on the viscosity of TM gel. However, the viscosity of gel increased as the PF127 concentrations increased. The viscosity of formulations containing thickening agents was in the order of PF-MC 3%>PF-HPMC 2%>PF-CMC 2.5%>PF127 15%. The slowest drug release was obtained from 15% PF127 formulations containing 3% methylcellulose. In vivo study showed that the ocular bioavailability of TM, measured in albino rabbits, increased by 2.5 and 2.4 fold for 25% PF127 gel formulation and 15% PF127 containing 3% methylcellulose, respectively, compared with 0.5% TM aqueous solution.

Preparation and evaluation of ketoprofen floating oral delivery system.

A sustained release system for ketoprofen designed to increase its residence time in the stomach without contact with the mucosa was achieved through the preparation of floating microparticles by the emulsion-solvent diffusion technique. Four different ratios of Eudragit S100 (ES) with Eudragit RL (ERL) were used to form the floating microparticles. The drug retained in the floating microparticles decreased with increase in ERL content. All floating microparticle formulations showed good flow properties and packability. Scanning electron microscopy and particle size analysis revealed differences between the formulations as to their appearance and size distribution. X-ray and DSC examination showed the amorphous nature of the drug. Release rates were generally low in 0.1 N HCl especially in presence of high content of ES while in phosphate buffer pH 6.8, high amounts of ES tended to give a higher release rate. Floating ability in 0.1 N HCl, 0.1 N HCl containing 0.02% Tween 20 and simulated gastric fluid without pepsin was also tested. The formulation containing ES:ERL1:1 (FIII) exhibited high percentage of floating particles in all examined media.

Manipulation of powder characteristics by interactions at the solid-liquid interface: 1-sulphadiazine.

A solvent-treatment technique aiming at manipulating the properties of powdered materials is reported. Potentials of the technique were assessed using sulphadiazine (SD). A suspension of the drug in a preselected solvent (5% aqueous ammonia solution) was stirred under controlled conditions. The solvent was subsequently removed and the material dried. The effect of experimental variables such as stirring speed and time, powder/solvent ratio and inclusion of additives (Tween 80, sodium chloride and PVP) on the properties of solvent treated SD was assessed. Data obtained were compared with those for SD recrystallized under identical conditions. Solvent treatment of SD in the absence of additives resulted in a limited change in crystal morphology as indicated by SEM. This was associated with improved flowability and a limited reduction in dissolution rate relative to untreated SD. On the other hand, recrystallized SD exhibited superior flowability but a considerably low dissolution rate. Solvent treatment of SD in the presence of 2% PVP produced a microgranular directly compressible material.