Ashraf Abu-Seida

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

The North Atlantic Oscillation and the Arctic Oscillation are modes of climate variability affecting temperature and precipitation in the mid-latitudes. Here we use reanalysis data and climate model simulations of historical and warm climates to show that the relationship between the two oscillations changes with climate warming. The two modes are currently highly correlated, as both are strongly influenced by the downward propagation of stratospheric polar vortex anomalies into the troposphere. When considering a very warm climate scenario, the hemispherically defined Arctic Oscillation pattern shifts to reflect variability of the North Pacific storm track, while the regionally defined North Atlantic Oscillation pattern remains stable. The stratosphere remains an important precursor for North Atlantic Oscillation, and surface Eurasian and Aleutian pressure anomalies precede stratospheric anomalies. Idealized general circulation model simulations suggest that these modifications are linked to the stronger warming of the Pacific compared with the slower warming of the Atlantic Ocean.

Abstract Titanium dioxide nanoparticles (TiO2 NPs) are used in numerous products, such as paints, pharmaceuticals, environmental sanitizing agents and even as a whitening food additive (E171). Residual TiO2 NPs are considered among the emerging contaminants of aquatic environments. However, the effect of such exposure on intestinal microbiota population, microbial disease resistance and the immune-related gene expression of Nile tilapia (Oreochromis niloticus) is largely obscure. Three groups of fish were nurtured on diets containing 1 mg/ml TiO2 NPs with three different sizes (53, 31 and 13 nm), beside the control group for four weeks before sampling fish tissues. Fish groups fed on TiO2NPs diets showed significantly increased higher levels of tumour necrosis factor (TNF-α), interleukin (IL-6) and IL-1?, along with insignificant changes in IL-8 and IL-10 compared with the control group. These changes indicate a strong inflammatory response. Treated fish groups showed a marked decrease in the count of some intestinal microbiota, aeromonas, pseudomonas and lactobacillus. Fish were challenged against A. hydrophila, and a higher mortality rate was observed in the group fed on smaller TiO2 NPs (13 nm). The levels of antioxidant enzymes such as catalase, glutathione peroxidase and superoxide dismutase were significantly increased in groups fed on TiO2 NPs, while metallothionein levels were only slightly changed. In conclusion, feeding fish with diets containing TiO2 NPs (13 and 31 nm) for 4 weeks alters the intestinal microbiota population and provides additional information on the toxic impacts of TiO2 NPs on the health and immune status of O. niloticus.

The goal of this research was to evaluate the beneficial effects of topical curcumin loaded freeze-dried wafers in wound healing. Curcumin wafers were fabricated by cross-linking of chitosan with beta glycerophosphate under magnetic stirring. Composite wafers were prepared by the addition of sodium hyaluronate. Wafers were fabricated by freeze-drying technique. The resulted wafers were examined by naked eye and their dimensions were measured using a caliper. % Drug content, in-vitro release and % water uptake tests were conducted to characterize the fabricated wafers. Porosity testing, compressive mechanical behavior, morphological examination using scanning electron microscopy, thermal behavior using differential scanning calorimetry and Fourier transform infrared spectroscopy were all carried out on the optimized cross-linked wafers followed by their microbiological assays and cytotoxicity studies. The results showed that the optimized wafers possessed high water uptake capabilities while entertaining very high porosity levels (86-89%). Microbiological assay revealed the superiority of the selected curcumin wafers versus free curcumin in bacterial growth inhibition against Staphylococcus epidermidis and Staphylococcus aureus (MRSA) bacteria. The anti-inflammatory effects of the selected curcumin wafers were evaluated against pro-inflammatory cytokines. The results suggested that they were significantly better than free curcumin in lowering cytokines levels. To conclude, the obtained findings revealed that curcumin wafers offered a promising solution in the field of wound healing.

Exaggerated inflammatory responses may cause serious and debilitating diseases such as acute lung injury and rheumatoid arthritis. Two series of chalcone derivatives were prepared as anti-inflammatory agents. Methoxylated phenyl-based chalcones 2a-l and coumarin-based chalcones 3a-f were synthesized and compared for their inhibition of COX-2 enzyme and nitric oxide production suppression. Methoxylated phenyl-based chalcones showed better inhibition to COX-2 enzyme and nitric oxide suppression than the coumarin-based chalcones. Among the 18 synthesized chalcone derivatives, compound 2f exhibited the highest anti-inflammatory activity by inhibition of nitric oxide concentration in LPS-induced RAW264.7 macrophages (IC50 = 11.2 μM). The tested compound 2f showed suppression of iNOS and COX-2 enzymes. Moreover, compound 2f decreases in the expression of NF-κB and phosphorylated IκB in LPS-stimulated macrophages. Finally, docking studies suggested the inhibition of IKKβ as a mechanism of action and highlighted the importance of 2f hydrophobic interactions.

A simple RP-HPLC-DAD method was developed and validated, as per the ICH guidelines, for simultaneous determination of naphazoline HCl (NPZ) & pheniramine maleate (PHN) along with three of their official impurities. Chromatographic separation was performed on a hypersil ODS column (5 mm, 250–4.6 mm i.d.) with isocratic elution using phosphate buffer pH 6.0: acetonitrile (70 : 30, v/v) as mobile phase, at a flow rate of 1.0 mL min−1 and UV detection at 260.0 nm. The developed method was found to be linear over the concentration ranges of 5.00–45.00 μg mL−1 for NPZ and NPZ impurity B and 10.00–110.00 μg mL−1, 10–70 μg mL−1 and 10–120 μg mL−1 for PHN, and PHN impurity A and B, respectively, with correlation coefficient values <0.999 for the five cited compounds. The method was confirmed to be accurate, robust and precise with RSD >2.0%. LOD and LOQ values for the five cited compounds were calculated. Moreover, the method was also validated in rabbit aqueous humor as per the US food and drug administration (FDA) bioanalytical validation guidelines. Finally, the proposed method was applied for the analysis of the two drugs along with their impurities in dosage form and spiked aqueous humor samples.

Evaporation from free water surface is considered a very important constituent in both the energy and hydrologic cycles. Precise measurement of evaporation from the free water surface is almost impossible. This is why we need a calculation model for free water evaporation. In this study, a simple mass-transfer evaporation model was developed to be applicable over Lake Nasser in the hyper-arid region located in the south of Egypt. Measured meteorological data (2011–2014) at two stations, Aswan and Abu-Simbel, were used to calculate free water surface evaporation using Priestly–Taylor equation. Priestly–Taylor equation was used because it is the most appropriate equation for Lake Nasser evaporation according to the literature. Results from this model were used to develop a simple mass-transfer evaporation model. The statistical analysis for both calibration and validation periods were very good. The slope of the regression line is about 0.9, with a coefficient of determination of 0.98. The t value is 0.6, at p value of 0.544, which is much greater than 0.05. The developed model could be used with confidence at Aswan meteorological station or on the average of the two meteorological stations, while it should be used carefully on Abu-Simbel meteorological station.

In the current work, a series of novel 4-benzyloxy and 4-(2-phenylethoxy) chalcone fibrate hybrids (10a-o) and (11a-e) were synthesized and evaluated as new PPARα agonists in order to find new agents with higher activity and fewer side effects. The 2-propanoic acid derivative 10a and the 2-butanoic acid congener 10i showed the best overall PPARα agonistic activity showing Emax% values of 50.80 and 90.55%, respectively, and EC50 values of 8.9 and 25.0 μM, respectively, compared to fenofibric acid with Emax = 100% and EC50 = 23.22 μM, respectively. These two compounds also stimulated carnitine palmitoyltransferase 1A gene transcription in HepG2 cells and PPARα protein expression. Molecular docking simulations were performed for the newly synthesized compounds to study their predicted binding pattern and energies in PPARα active site to rationalize their promising activity. In vivo, compounds 10a and 10i elicited a significant hypolipidemic activity improving the lipid profile in triton WR-1339-induced hyperlipidemic rats, including serum triglycerides, total cholesterol, LDL, HDL and VLDL levels. Compound 10i possessed better anti-hyperlipidemic activity than 10a. At a dose of 200 mg/kg, it demonstrated significantly lower TC, TG, LDL and VLDL levels than that of fenofibrate at the same dose with similar HDL levels. Compounds 10i and 10a possessed atherogenic indices (CRR, AC, AI, CRI-II) like that of fenofibrate. Additionally, a promising antioxidant activity indicated by the increased tissue reduced glutathione and plasma total antioxidant capacity with decreased plasma malondialdehyde levels was demonstrated by compounds 10a and 10i. No histopathological alterations were recorded in the hepatic tissue of compound 10i (200 mg/kg).