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Search Results: 1 - 10 of 167573 matches for " Thanaa E. "
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Irradiation Effect on Photodegradation of Pure and Plasticized Poly (4-Methylstyrene) in Solid Films  [PDF]
Saria A. Al Safi, Thanaa M. Al Mouamin, Wadhah N. Al Sieadi, Khalid E. Al Ani
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.55036

The photodegradation of irradiated thin films of poly (para-methylstyrene) with 265 nm radiations in the presence of airand as a function of irradiation time has been studied using UV-VIS, fluorescence and FT-IR Spectroscopic techniques. The influence of phthalate and terephthalate plasticizers on stability of poly (para-methylstyrene) towards irradiations was also investigated. Blending with phthalate plasticizers was found to cause a higher efficiency of photodegradation than that obtained in doping with terephthalate plasticizers. The intensity of absorption was also found to increase with time of irradiation and in change in the shape of the spectra at longer wavelength, thus indicating a possibility of photodegradation of polymer chains. The analysis of the FT-IR spectra of the irradiated and non-irradiated samples, shows a predominant absorption associated with carbonyl compounds with 1740 cm-1. In addition, the observed increase in the intensities of the carbonyl and hydroxyl regions of the FT-IR spectra, have provided an evidence for the photodegradation as well as photo-oxidation of polymeric chains. The presence of the plasticizer in the polymer backbone was found to accelerate the photodegradation of polymeric chains.

Therapeutic Diets for Diarrhea: Biological Evaluation in Rats
Thanaa E. Hamed,Afaf Ezzat,Sahar Y. Al-Okbi
Pakistan Journal of Biological Sciences , 2003,
Abstract: The present research dealt with the evaluation of the anti-diarrheal activity of two therapeutic diets in model of castor oil induced diarrhea in rats. Formula I contain modest amount of skimmed milk, formula II was lactose restricted diet. Both formulae contain cereals, legumes, honey and edible source having anti-diarrheal activity. The nutritional value of the two formulated therapeutic diets was evaluated in normal growing rats in comparison to reference formula, milupa special formula, in addition to control balanced diet (contain 10% protein supplemented from casein). The evaluation of nutritional value depended on determination of total food intake, body weight gain, food efficiency ratio and protein efficiency ratio. Nutritional status of rats fed different diets was also evaluated through determination of certain biochemical parameters such as percentage haematocrit, blood haemoglobin concentration, plasma total protein, albumin, iron, phosphorus, zinc, magnesium, retinol and -carotene. Results showed that anti-diarrheal activity of formula I was superior compared to formula II. Milupa and formula I have higher values of protein efficiency ratio and food efficiency ratio than control casein diet which were significant in case of Milupa. However diet II showed comparable values to control. Biochemical parameters showed higher values of plasma total protein, magnesium and retinol of rats fed Milupa diet. Feeding diet II produced significant increase of plasma iron magnesium and retinol. However, only significant increase of plasma magnesium has been observed when feeding diet I.
Reduction in hypercholesterolemia and risk of cardiovascular diseases by mixtures of plant food extract: a study on plasma lipid profile, oxidative stress and testosterone in rats
Mohamed, Doha A.,Hamed, Thanaa E.,Al-Okbi, Sahar Y.
Grasas y Aceites , 2010, DOI: 10.3989/gya.021210
Abstract: The present study was postulated to prepare and evaluate the influence of two plant food extract mixtures on plasma lipid profile, oxidative stress and testosterone levels in rats fed a hypercholesterolemic diet. The safety of the studied extract mixtures was evaluated through the determination of liver and kidney functions. The total phenolic contents, tocopherols, fatty acids and unsaponifiable matter (UNSAP) in the extract mixtures were determined. Rats fed a hypercholesterolemic diet were given a daily oral dose (300 mg/kg rat body weight) of either mixture I or II for a month and compared with a control hypercholesterolemic group and a normal control group. Results showed that α-tocopherol was 0.750 and 4.017 mg, γ-tocopherol was 0.564 mg and 0 and δ-tocopherol was 15.23mg and 0.634mg/100g for mixtures I and II, respectively. The phenolic contents in mixtures I and II were 36.74 and 23.72 g gallic acid equivalent/100g mixture, respectively. The GLC investigation of UNSAP revealed that stigmasterol and b-sitosterol were the major phytosterols in mixtures I and II, respectively followed by campesterol in both. The GLC analysis of the fatty acids showed that oleic acid was the major fatty acid in both extract mixtures. Results from the animal experiment showed that feeding a hypercholesterolemic diet produced a significant increase in total lipids, total cholesterol (T-Ch), triglycerides (TGs), low density lipoprotein cholesterol (LDLCh), T-Ch/HDL-Ch, TGs/HDL-Ch and malondialdehyde (MDA) and a significant reduction in high density lipoprotein cholesterol (HDL-Ch), vitamin E, b-carotene and testosterone. Rats fed a hypercholesterolemic diet and given mixture I or II showed significant improvements in plasma lipid profile compared to the hypercholesterolemic control group. This improvement was associated with a significant reduction in oxidative stress reflected by an elevation in plasma levels of antioxidants (vitamin E and b-carotene) and a reduction in plasma MDA levels. The plasma level of testosterone increased significantly in the rats fed the hypercholesterolemic diet and given mixture I or II compared to the hypercholesterolemic control. Plasma testosterone showed a significant negative correlation with plasma TGs and TGs/HDL-Ch in the hypercholesterolemic control rats. The studied extract mixtures showed complete safety towards liver and kidney functions. In conclusion the tested extract mixtures showed an improvement in the plasma lipid profile, a significant increase in testosterone and a decrease in oxidative stress with promising prevention
Comparative Study on the Efficiency of Using Pulsed and Direct Current Electrochemotherapy in Treating Ehrlich Tumor
Mamdouh M. Shawki,Mohammed A. Elblbesy,Thanaa E. Shalaby,Metwali A. Qotb
International Journal of Biomedical Science , 2012,
Abstract: The Electrochemotherapy (ECT) is an effective treatment of cutaneous and subcutaneous solid tumors. Electric field is applied to tumor nodules to enhance the delivery/distribution of a non-permeable or poorly permeable chemotherapeutic agent into the tumor cells thereby increasing local concentration of anticancer drugs. The aim of this study was to evaluate the effectiveness of using two types of electric fields in ECT, pulsed sine waves and direct current (DC) application in addition to intra-tumoral injection of bleomycin (BLM), a cytotoxic drug for treating Ehrlich tumor. The electric fields were delivered through six stainless steel needle electrodes inserted into the tumor. Tumor volume, tumor mass, percentage of fragmented DNA in the tumor tissue, relative spleen mass/total body mass, mortality rate, histological and ultrastructural examinations were investigated in each group. There were 40% complete response (CR) and 60% partial response (PR) in the group treated with DC as the electric field source of ECT, while 0% (CR) and only 25% (PR) were found in the group treated with pulsed sine wave ECT. We concluded that the utilization of low dose DC for ECT gives better results than the low voltage pulsed sine waves in treating Ehrlich tumor which may be due to the dual effects of electrochemical reactions evoked by DC application and the anti-cancer activity ofBLM.
Thanaa A. El-Masry *, Magda E. El Sayaad , Ibrahim A. Gaaboub and Wafaa M. Fouda
International Journal of Pharmaceutical Sciences and Research , 2013,
Abstract: Capsaicin, the pungent ingredient of red pepper, is used topically to treat different types of neuropathic pain, in rat model of vincristine induced neuropathic pain we tried to investigate the effect of capsaicin on sciatic nerve through electrophysiological and histopathological studies. We found that treatment of animals with vincristine results in significant decrease in sciatic nerve conduction velocity and degeneration of the nerve fibers, where combined treatment of vincristine and capsaicin showed highly significant decrease in sciatic nerve conduction velocity and degeneration of the nerve fibers compared with that treated with vincristine only. In new trial, we tried to investigate the effect of direct capsaicin titration on sciatic nerve fibers that results in nearly abolishment of nerve conduction velocity. All of these findings may illustrate the mechanism of capsaicin effect through afferent nerves degeneration.
Extent and Mode of Degradation of RNA Monomers by Extracts of Penicillium politans NRC 510
Thanaa H. Ali
Journal of Biological Sciences , 2006,
Abstract: Extracts of Penicillium politans NRC 510 catalyzed dephosphorylation of CMP, UMP, GMP and AMP optimally at pH 6 and 40°C. They also catalyzed deamination of cytidine and adenosine out of the tested ribonucleotides, ribonucleosides and bases. Neither cleavage of the N-glycosidic likages of these nucleotides nor those of the corresponding nucleosides could be effected by the extracts. Phosphate liberation from the four RNA monomers was effected by phosphate-non repressible acid phosphatase. The affinity of the phosphatase for the different ribonucleotides was in the order of magnitude CMP > UMP > GMP > AMP. Freezing and thawing of the extracts had no effect on the activity of the phosphatase or on that of the aminohydrolase. However, heating the extracts at 60°C for 30 min, in absence of the substrate, inactivated the phosphatase and increased the activity of the deaminase about 50%. No evidence for the involvement of specific nucleotidases in ribonucleotides dephosphorylation was recorded. Separation of the phosphohydrolase from the aminohydrolase was achieved using Sephadex G-100 column chromatography.
Resistance Functions for Two Spheres in Axisymmetric Flow—Part I: Stream Function Theory
Thanaa El Naqeeb,Rudi Schmitz
Journal of Applied Mathematics , 2011, DOI: 10.1155/2011/318907
Abstract: We consider low-Reynolds-number axisymmetric flow about two spheres using a novel, biharmonic stream function. This enables us to calculate analytically not only the forces, but also the dipole moments (stresslets and pressure moments) and the associated resistance functions. In this paper the basics properties of axisymmetric flow and the stream function are discussed. Explicit series expansions, obtained by separation in bispherical coordinates, will be presented in a follow-up paper. 1. Introduction The grand resistance and mobility tensors describe the hydrodynamic interaction between rigid bodies suspended in a fluid medium and play an all-important role in colloidal science [1–7]. More specifically, they express the linear relationship between the Cartesian force multipole moments exerted by the particles on the fluid and the gradients of the ambient flow velocity taken at the particle centers. Both tensors depend, in general, on the positions and orientations of all the suspended particles. However, in the special case of just two spherical bodies, owing to O(2)-symmetry about the line connecting the particle centers, the full tensors can be reduced to a set of scalar resistance and mobility functions [8–15]. Accurate knowledge of the two-body resistance functions is essential to overcome certain contact singularities—also referred to as lubrication singularities—that dominate the many-body tensors when a pair of particles comes close to touching [16, 17]. The calculation of the 2-body resistance functions is based on the solution of the Stokes boundary value problem for stationary, low-Reynolds number flow about two spheres. In this case there exists a set of curvilinear coordinates that is adapted to the physical boundaries at hand—the bispherical coordinates—and it seems natural to try to solve the problem analytically by separation in these coordinates [18–21]. However, separation of the Stokes equations in bispherical coordinates succeeds only up to a modulation factor [22], which complicates matching of the general solution to the boundary data. In most cases, it turns out that the matching problem can be reduced to a linear recursion problem that involves an infinite tridiagonal matrix. Although this cannot, in general, be solved analytically, the numerical treatment of such a tridiagonal recursion scheme [23–28] is much more efficient than recursions based on the twin-multipole expansion [9, 12–14]. Further progress can be made if the flow is axisymmetric, which happens when the spheres translate along or rotate around the line connecting
Detection of the Antitumor Glutaminase-Asparaginase in the Filamentous Fungi
Tahany A. Elzainy,Thanaa H. Ali
Journal of Applied Sciences , 2006,
Abstract: Extracts of nitrate-grown mats of Aspergillus niger NRRL3 catalyzed, with comparable efficiency, hydrolytic deamidation of both L-glutamine and L-asparagine in a similar manner under different experimental conditions. Other amides such as acetamide, nicotinamide and nicotinamide adenine dinucleotide could not be deamidated by these extracts. Optimum deamidation of the two amino acids by the extracts was recorded at pH 6 of 0.08 to 0.16 M phosphate buffer and 60°C. Exposure of the extracts to 60°C for 20 min in absence of the substrate revealed about 70% increase in each of the two activities. Fractionation of the extract proteins using DEAE Sephadex A-25 column chromatography showed that the glutaminase and asparaginase activities were detected in the same protein fractions with the same peak and with almost constant ratios. The ratio of the glutaminase activity to that of the asparaginase was approximately 0.7 to 1.0. The activities of the pooled fractions towards L-glutamine and L-asparagine showed similar behaviors at different pH values and at different temperatures. Both activities exhibited hyperbolic substrate saturation kinetics and the apparent km values were found to be 5.05 and 2.57x10-3 M for L-glutamine and L-asparagine, respectively. The sum of the two activities was much less than additive on using an equimolar mixture of L-glutamine and L-asparagine as substrates. Each of the two activities was not inhibited by the products of the reaction but inhibited by Mg++ or Hg++. Both activities were inactivated at almost the same rate on exposure to temperatures above 40°C and were retained in the freezer for some months. The same type of enzyme was also suggested to occur in a strain of Penicillium chrysogenum and in a strain of Penicillium politans.
Mitomycin-C needle bleb revision in congenital glaucoma
Mohamed Elsayed Thanaa,Mohamed El-Raggal Tamer
Middle East African Journal of Ophthalmology , 2010,
Abstract: Purpose and Settings: This study was designed to evaluate the efficacy and safety of mitomycin-C (MMC) augmented needling procedure in the management of failed bleb after trabeculectomy in congenital glaucoma. This study was carried out at Ain Shams University Hospital. Patients and Methods: A retrospective study was carried on 30 eyes of 25 patients with congenital glaucoma with bleb failure after trabeculectomy. The mean age of the subjects was 7.3 ± 3.4 years (range, 1-12 years). Under general anesthesia, needling procedure was performed with adjunctive use of a mixture of 0.1 mL of MMC (0.04 mg/mL) and 0.2 mL of lidocaine 1% injected subconjunctivally. Needling was performed with a 30-gauge needle to dissect the areas of subconjunctival fibrosis and re-establish aqueous outflow. Results: Follow-up ranged from 6 to 20 months (mean, 9.23 ± 5.25 months). One needling revision was performed in 22 eyes (73.3%) and eight eyes (26.7%) received two needle revisions. The mean intraocular pressure (IOP) decreased from 26.9 ± 2.85 mmHg (range, 21-34 mmHg) before surgery to 15.63 ± 3.15 mmHg (range, 10-24 mmHg) at last follow-up. Complications included significant subconjunctival hemorrhage in six eyes, intraoperative bleb leak in two eyes, choroidal detachment in one eye, and minimal hyphema in one eye. Conclusion: MMC needle bleb revision appears to be an effective method to revive failed filtration surgery after trabeculectomy in patients with congenital glaucoma. This technique is effective in reducing IOP with preservation of the remaining conjunctiva for further surgery.
Journal of Applied Sciences in Environmental Sanitation , 2011,
Abstract: Extracellular keratinase was produced during submerged aerobic cultivation in a medium containing chicken feather for enzyme synthesis. The en-zyme was partially purified by acetone fractionation and DEAE-Sephadex A-25 column chromatography. A purification fold about 20.7 with a yield of 37.9% as determined with keratin as substrate of the activity in crude extracts. Specific activity of this partially purified enzyme is 2312.7 U/mg. The km and Vmax values were 7.15 mM and 300U/ml respectively. The optimal pH and temperature for keratinolytic activity was approximately 7.0 and 70°C respectively. Essential amino acids like threonine, valine, methionine, isoleucine, leucine, lysine, histidine and tyrosine as well as ammonia were produced when feathers were used as substrates. Exposures of purified keratinase in absence of substrate at 80°C, for 60 minutes caused lose about 56% of its activity. This keratinase was inhibited in a variable rates by addition of EDTA, CuSO4, ZnCl2 MnCl2 and HgCl2 at a concentration of 15mM, where as iodoacetate and 2-mercaptoethanol slightly activation at the same concentration. Strain Aspergillus oryzae, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.
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