Al-Ajerami Y.,Al - Azhar University of Gaza
Eastern Mediterranean Health Journal | Year: 2012
The aim of this study was to evaluate the sensitivity and specificity of ultrasound in the diagnosis of acute appendicitis at Al-Shefa hospital, Gaza Strip, Palestine. Patients who had appendicitis diagnosed by ultrasound over the study period (n = 180) underwent surgical excision of the appendix. The negative appendectomy rate was low, with only 4.4% (8/180) false positives. A significantly higher false diagnosis rate (false negatives + false positives) was obtained in female patients than in males: 38.5% versus 6.2%. A high proportion of falsely diagnosed cases had abnormal weight (overweight or obese) (82.1%). The overall sensitivity and specificity of ultrasound, using surgical outcome as the gold standard, were 84.8% and 83.3% respectively, and the positive and negative predictive values were 93.3% and 66.7% respectively. Sensitivity and specificity were higher in males (95.7% and 88.2% respectively) than females (84.6% and 71.4% respectively).
Al Laham N.A.,Al - Azhar University of Gaza
Journal of Infection and Public Health | Year: 2012
Objectives: This study was conducted in general operating theaters at public and private hospitals in the Gaza Strip, Palestine to determine the prevalence of bacterial contamination of different objects. Methods: Swabs were collected from 21 items that were distributed over three categories (equipment, environment and personnel). In total, 243 swabs were collected at pre- and post-operation stages and were cultured and identified using standard microbiological procedures. Results: The results show that 24.7% of the swabs were contaminated with microorganisms. The equipment, environment and personnel were responsible for 45%, 48.3% and 6.7% of contamination, respectively. The rate (26.9%) of contamination in the post-operation samples was higher than in the pre-operation samples (22.6%), but the difference was not statistically significant. In addition, there was not a statistically significant increase in the prevalence of contamination in private (28.7%) compared to public hospitals (21.8%). Of the seven bacterial genera that were recovered, the highest percentage belonged to Staphylococcus spp. (45.3%) followed by Enterobacter spp. (23.4%). Conclusions: This study reveals a moderate percentage of contamination in our public and private hospital general operating theaters, which may increase the risk factors for developing surgical-site infections. These observations justify more attention being paid to infection-control efforts in our hospitals. © 2011 King Saud Bin Abdulaziz University for Health Sciences.
Lubbad S.H.,Al - Azhar University of Gaza
Journal of Chromatography A | Year: 2016
Poly(methyl styrene-co-bis(p-vinylbenzyl)dimethylsilane)-based monolithic capillary columns were optimized for separation of low, medium, and high molecular-weight analytes. The morphology and consequently the chromatographic performance of these monoliths were tuned by changes in the volume-ratio of monomer to macroporogen, establishing good monolithic flow-through and retention pores. Two monoliths were prepared and analyzed by reversed-phase chromatographic separation of low molecular-weight analytes such as alkyl benzenes and β-blockers, as well as medium and high molecular-weight analytes such as peptides and proteins, respectively. The microstructure was studied by scanning electron microscopy (SEM), and by inverse-size exclusion chromatography (ISEC). Monolith 1 demonstrated a high retention of alkyl benzenes, which coeluted from the column at the washing step of absolute acetonitrile; yet this monolith established a baseline separation of 9-peptide and 8-protein mixtures. Monolith 2 demonstrated efficient separation of the three analyte groups of different molecular weights. Six alkyl benzenes and five β-blockers were base-line separated in less than 5 and 2. min, respectively, with good resolution and very small values of peak width at half height. Moreover, a comparable performance of efficient separation of the 9-peptide mixture and a fast separation of 5- and 8-protein mixtures were achieved. Both monoliths were characterized by high mechanical strength, high permeability, and excellent reproducibility. © 2016 Elsevier B.V.
EL Tayyan A.A.,Al - Azhar University of Gaza
Turkish Journal of Physics | Year: 2013
This article suggests a simple method of modeling and simulation of photovoltaic systems. The main goal is to find the parameters (Iph , Io , Rs , Rsh, and a) of the single-diode model by adjusting the P-V curve and/or I-V curve at parameters provided by the manufacturer specification sheets ( Isc , Voc , I mp, and Vmp). An empirical model is incorporated into the single-diode model in order to remove its implicit nature and to ease the calculations. Calculations using this method can be extended to generate the I-V curves at temperatures and irradiances other than the standard test condition (STC).
Alkahlout A.,Al - Azhar University of Gaza
Physics Research International | Year: 2015
Transparent conducting Ga:ZnO (GZO) and Al:ZnO (AZO) layers have been deposited by spin coating on glass substrates using crystalline nanoparticles redispersed in 1-propanol. The coatings have been sintered in air at 600°C for 15 min and then postannealed in a reducing atmosphere at 400°C for 90 min. The effect of Ga and Al doping on the structural, morphological, optical, and electrical properties of the obtained thin films was investigated. Both films were found to be crystalline with a hexagonal structure. A single step spin coated layer 52-56 nm thick is obtained. To increase the thickness and lower the obtained sheet resistance multilayers coatings have been used. The visible transmission of both layers is high (T>80%). The influence of the sintering temperature and the optimum doping concentration was investigated. Five layers synthesized with doping ratio of 1 mol.% and sintered at 600°C and then submitted to reducing treatment in forming gas exhibited a minimum resistivity value of 7.4 × 10-2 Ω·cm for GZO layer and 1.45 Ω·cm for AZO coating. © 2015 A. Alkahlout.
Sirdah M.M.,Al - Azhar University of Gaza
Diabetes and Metabolic Syndrome: Clinical Research and Reviews | Year: 2015
Taurine, 2-amino ethanesulfonic acid, is a conditionally essential β amino acid which is not utilized in protein synthesis. Taurine is one of the most abundant free amino acids in mammals tissues and is one of the three well-known sulfur-containing amino acids; the others are methionine and cysteine which are considered as the precursors for taurine synthesis. Different scientific studies emphasize on the cytoprotective properties of taurine which included antioxidation, antiapoptosis, membrane stabilization, osmoregulation, and neurotransmission. Protective and therapeutic ameliorations of oxidative stress-induced pathologies were also attributed to taurine both in experimental and human models. Data demonstrating the beneficial effectiveness of taurine against type 1 and type 2 diabetes mellitus and their complications are growing and providing a better understanding of the underlying molecular mechanisms. Although the clinical studies are limited compared to the experimental ones, the present updated systematic review of the literature is set up to provide experimental and clinical evidences regarding the effectiveness of taurine in the context of diabetes mellitus and its complications. Gathering these scientific effects of taurine on diabetes mellitus could provide the physicians and specially the endocrinologists with a comprehensive overview on possible trends in the prevention and management of the disease and its complications through antioxidant supplementation. © 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved.
El Deeb S.,Al - Azhar University of Gaza
Chromatographia | Year: 2010
An LC method was developed and validated for the enantioselective separation and enantiomeric impurity quantitation of atenolol. Separation of the atenolol enantiomers on the Chirobiotic V2 (150 mm × 4.6 mm, 5 μm) column was best achieved using a ternary mobile phase of methanol-acetonitrile- triethylamine acetate 0.5% (w/v), pH 4.5 in a ratio of (45:50:5; v/v/v). Good resolution value of R s = 3 was obtained at a flow rate of 1 mL min-1 within a total run time of less than 40 min. Peak identification was achieved using the standard reference of individual enantiomers. The peak of the impurity was eluted in front of the peak of the main enantiomer. Detection was performed by UV at 226 nm. Within and between day's repeatabilities for both retention time and peak area were investigated at three concentration levels and found to be low. The method was also found to be efficient for the determination of atenolol enantiomeric impurity. An impurity quantitation level of (R)-atenolol down to 0.08% relative to the main enantiomer (S)-atenolol was found possible. © 2010 Vieweg+Teubner Verlag | Springer Fachmedien Wiesbaden GmbH.
Alhendawi H.M.H.,Al - Azhar University of Gaza
Journal of Materials Chemistry | Year: 2011
The intercalation of malachite green (MG) in γ-zirconium phosphate (γ-ZrP) and one of its cationic surfactant forms (γ-ZrP/SUR +) has been investigated by the batch method and followed by X-ray diffractometry. X-Ray diffraction patterns showed that an impure phase (1.18 and 1.96 nm) was obtained with γ-ZrP while a pure one (2.47 nm) with γ-ZrP/SUR+ at a dye loading of 14% and 18%, respectively. In both cases, computer models and calculations based on the dye dimensions and the structure of the host showed that the maximum ion-exchange capacity is ca. 12-16%, which reflects the very high capacity by which γ-ZrP and γ-ZrP/SUR+ are characterized in the uptake of MG. The difference in the dye loading between the corresponding derivatives of pristine γ-ZrP and γ-ZrP/SUR+ is attributed to the difference in interlayer distances and the variable cross-section of the dye depending on its orientation and/or conformation within the interlayer region. © 2011 The Royal Society of Chemistry.
Al-Kahlout A.,Leibniz Institute for New Materials |
Al-Kahlout A.,Al - Azhar University of Gaza
Thin Solid Films | Year: 2012
Nanoscale zinc oxide (ZnO) powder with Brunauer-Emmelt-Teller surface area of 43 m 2 g - 1 has been synthesized by soft chemistry at low temperature via reaction of zinc acetate dehydrate (Zn(CH 3COO) 2.2H 2O) and sodium hydroxide (NaOH). The influence of the pH value of the sol on the structure and morphology of ZnO powder have been investigated by X-Ray Diffraction, Scanning Electron Microscopy and High Resolution Transmission Electron Microcopy. Their thermal properties have been determined by simultaneous Differential Thermal Analysis and Thermogravimetry coupled to Mass Spectroscopy analysis. The nanoparticles are single crystals with (101) preferred orientation but agglomerated. Their crystallite size can be adjusted from 15 nm to 35 nm by controlling the pH value between 7 and 13. Thick porous crystalline coatings have been obtained by doctor blade coating on conducting SnO 2:F glass substrates using pastes prepared by wetting the crystalline powders with polyethylene glycol and water. After sintering at 400 °C and Ruthenium 535 dye sensitization, the coatings have been tested in a three electrode electrochemical cell containing an appropriate electrolyte in the dark and under 450 W Xenon lamp illumination. The influence of the electrolyte iodine concentration, the film thickness and the light intensity on the current density are presented and discussed. Such coatings appeared promising for the realization of dye sensitized solar cells. © 2011 Elsevier B.V. All rights reserved.
Alhendawi H.M.H.,Al - Azhar University of Gaza
Journal of Solid State Chemistry | Year: 2013
In the present work, a chiral layered derivative of γ-zirconium phosphate (γ-ZrP) containing l-(+)-phosphoserine (γ-ZrP-PS*) covalently attached to inorganic layers has been prepared by means of topotactic exchange reaction. This organic-inorganic derivative is characterized by X-ray diffractometry, Solid 13C-NMR and FT-IR spectrophotometries and thermal analyses. A maximum level of topotactic replacement of 20% is achieved. Under both the acidic environment of the interlayer region of γ-ZrP and the acidic synthesis conditions, the hydrolysis of the ester bond of PS* is expected to take place to some extent. For this reason, it was impossible to exceed the recent percentage, which in turn reflects the relative moderate stability of the above mentioned bond under these conditions. In order to be more certain with regard to an expected further hydrolysis for this bond after separation, a sample of γ-ZrP-PS* was stored in a desiccator over a saturated solution of BaCl2 (90% relative humidity) for three months, and then the sample re-analyzed once again. Surprisingly, the results show that the sample still keeps almost the same level of exchange (i.e., 20%). Second, it is revealed that the sample almost gives the same spectroscopic and thermal behavior. This could be attributed to the less acidic character of the partially exchanged inorganic layers of the sample in comparison with that of the precursor γ-ZrP. Therefore, the PS* molecules persist and stay there into the interlayer gallery without further hydrolysis. © 2013 Elsevier Inc. All rights reserved.