Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

9 ( 1 )

2019 ( 163 )

2018 ( 284 )

2017 ( 283 )

Custom range...

Search Results: 1 - 10 of 146453 matches for " Mahmoud B. Sheier "
All listed articles are free for downloading (OA Articles)
Page 1 /146453
Display every page Item
Synthesis of Novel Acid Dyes with Coumarin Moiety and Their Utilization for Dyeing Wool and Silk Fabrics  [PDF]
Mahmoud S. Bashandy, Fatma A. Mohamed, Mohamed M. El-Molla, Mahmoud B. Sheier, Ahmed H. Bedair
Open Journal of Medicinal Chemistry (OJMC) , 2016, DOI: 10.4236/ojmc.2016.61002
Abstract: This article describes the synthesis of some novel coumarin compounds to use as acid dyes by using compounds 1 - 4 as starting materials, which were prepared by interaction of 2-hydroxybenzaldehyde with ethyl 3-oxobutanoate, diethylmalonate, 4-nitrobenzenediazonium chloride and 4-sulfobenzenediazonium chloride, respectively. Compound 1 reacted with bromine and 2-cyanoacetohydrazide to give phenacyl bromide derivative 5 and 2-cyanoacetohydrazone derivative 6, respectively. Coupling of compound 6 with equimolar amount of 2-sulfo-4-((4-sulfophenyl) diazenyl)benzenediazonium chloride gave coumarin acid dye 8. Phenacyl bromide derivative 5 re-acted with potassium cyanide in refluxing ethanol to produce compound 7, which on coupling with equimolar amount of 8-hydroxy-6-sulfonaphthalene-2-diazonium chloride and 8-hydroxy-3,6-disulfonaphthalene-1-diazonium chloride gave coumarin acid dyes 9 and 10, respectively. Interaction of compound 2 with 2-amino-5-((4-sulfophenyl)diazenyl)benzenesulfonic acid, benzene-1,4-diamine and 3,3’-dimethoxy-[1,1’-biphenyl]-4,4’-diamine in refluxing ethanol afforded compounds 11, 12 and 14, respectively. Diazonium sulphate of compounds 12 and 14 coupling with 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid gave compounds 13 and 15, respectively. Cyclocondensation of compound 3 with ethyl 3-oxobutanoate, diethyl malonate and malononitrile afforded derivatives of 3-acetyl-2H-chromen-2-one 16, ethyl 2-oxo-2H-chromene-3-carboxylate 17 and 2-imino-2H-chromene-3-carbonitrile 18, respectively. Reaction of sodium benzenesulfonate derivative 4 with ethyl 3-oxobutanoate and hydrazine hydrate gave compounds 19 and 20, respectively. The structures of the newly synthesized compounds were confirmed by elemental analysis, UV/ VIS, IR, 1H NMR and Ms spectral data. The suitability of the prepared dyestuffs for dyeing of wool and silk fabrics has been investigated. The dyed fabric shows good light fastness, very good rubbing, perspiration, washing and excellent sublimation fastness. These dyes have been color shade from blue to violet with very good depth and levelness on fabrics. The dye bath exhaustion and fixation on fabric has been found to be very good.
Using of the Generalized Special Relativity in Deriving the Equation of the Gravitational Red-Shift  [PDF]
Mahmoud Hamid Mahmoud Hilo
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.25045
Abstract: In this work we present a study of a new method to prove the equation of the gravitational red shift of spec-tral lines. That’s according to the generalized special relativity theory. The equation of the gravitational red shift of spectral lines has been studied in many different works, using different methods depending on the Newtonian mechanics, and other theories. Although attention was drawn to the fact that the well-known ex-pression of the gravitational Red-Shift of spectral lines may be derived with no recourse to the general rela-tivity theory! In this study a unique derivation has been done using the Generalized Special Relativity (GSR) and the same result obtained.
Development of New Strategy for Non-Antibiotic Therapy: Bovine Lactoferrin Has a Potent Antimicrobial and Immunomodulator Effects  [PDF]
Salama M. Abd El Hafez, Alaa B. Ismael, Manal B. Mahmoud, Abdel-Kader A. Elaraby
Advances in Infectious Diseases (AID) , 2013, DOI: 10.4236/aid.2013.33027

The antibiotic therapy has many problems, such as antibiotics resistance, hypersensitivity, direct toxicity, antibiotic-induced immunosuppresion and super-infections. This is highlighting the need for a new strategy for non-antibiotic therapy through the use of novel immunomodulators as naturally released ones (Lactoferrin). The present study investigates the potential of bovine lactoferrin (bLf), isolated from bovine milk whey, to prevent Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Streptococcus agalactiae (S. agalactiae) and Pseudomonas aeruginosa (P. aerogenosa) growth and then evaluates its immunomodulator effect. First, bLf isolation was attempted from bovine milk whey using a cation exchange chromatography by SP-Sepharose. Second, the antimicrobial activity assays were trailed to study the antimicrobial activity of bLf. Finally, the immune effect of bLf was studied by lymphocyte transformation test. It was found that bLf was separated around molecular weight of 80 kDa and showed significant inhibitory effect against E. coli followed by P. aeruginosa, S. agalactiae and S. aureus. bLf increased lymphocyte transformations mean values in a dose dependant manner. The highest transformations mean value was determined at 50 μg/mL. In conclusion, these results suggest that bLf is a potent natural antimicrobials and immunomodulator agent.

Computing the Pressure Drop of Nanofluid Turbulent Flows in a Pipe Using an Artificial Neural Network Model  [PDF]
Mahmoud S. Youssef, Ayman A. Aly, El-Shafei B. Zeidan
Open Journal of Fluid Dynamics (OJFD) , 2012, DOI: 10.4236/ojfd.2012.24013
Abstract: In this study, an Artificial Neural Network (ANN) model to predict the pressure drop of turbulent flow of titanium dioxide-water (TiO2-water) is presented. Experimental measurements of TiO2-water under fully developed turbulent flow regime in pipe with different particle volumetric concentrations, nanoparticle diameters, nanofluid temperatures and Reynolds numbers have been used to construct the proposed ANN model. The ANN model was then tested by comparing the predicted results with the measured values at different experimental conditions. The predicted values of pressure drop agreed almost completely with the measured values.
Mechanical properties of thoracic and abdominal arteries of sheep
K. Salim,B. A. Mahmoud,L. Karim
Advances in Theoretical and Applied Mechanics , 2012,
Major clinical and angiographic outcome of drug eluting stents in native ostial coronary artery disease  [PDF]
Khaled R. Abd El Meguid, Hesham B. Mahmoud, Fouad R. Amin, Jonathan R. Clague
World Journal of Cardiovascular Diseases (WJCD) , 2013, DOI: 10.4236/wjcd.2013.33051

Objectives: The study was designed to evaluate the efficacy and safety of drug eluting stents (DESs) in aorto-ostial (A-O) coronary artery lesions, in terms of early and late restenosis rate; including clinical assessment, non-invasive stress testing and angiographic follow-up. Also, the study was aimed to compare the results of implantation of drug eluting stents (DES) to that of bare metal stents (BMS) in aortoostial lesions done over a previous 5 years in Royal Brompton Hospital. Background: The safety and effectiveness of DESs for the treatment of aortoostial lesions. Methods: We included 161 consecutive patients with symptoms subjective of angina pectoris or objective evidence of myocardial ischemia; who underwent percutaneous coronary interventions (PCI) in coronary ostial lesions using DES. The patients were divided into two groups based on the site of ostial lesion. The control group consisted of 125 consecutive patients who underwent percutaneous coronary intervention for ostial lesions using bare metal stents (BMS) implantation in the period immediately before the introduction of DES. The incidence of major adverse cardiac events (MACE), including death or Q-wave myocardial infarction (MI), need for repeated revascularization procedure CABG or angioplasty, were recorded in-hospital and at twelve months ± 3 months. Follow-up angiography was only performed in case of recurrent symptoms subjective of myocardial ischemia or if there was objective evidence of myocardial ischemia by stress testing. Results: The initial procedure was successful in 149 patients (92.5%) in the DES arm. There were no statistically significant major in-hospital complications in the DES group, compared to BMS group which showed 4 cases of in-hospital deaths (p = 0.017). At Twelve months ± 3 months follow-up, MACE were significantly less frequent in the DES group compared to the BMS group, including death (0.8% vs. 6.4%, p = 0.004) and need for CABG (1.7% vs. 10%, p = 0.012). Conclusions: The main finding of our study is that, compared to the BMS, implantation

Reducing the Rate of Catheter-Associated Urinary Tract Infection in the Non-ICU Setting  [PDF]
Sameeh Ghazal, Syam Clara Viorica, Mercy Joseph, Mahmoud Mukahal, Ahmed Hakawi, Michael B. Edmond
Advances in Infectious Diseases (AID) , 2015, DOI: 10.4236/aid.2015.52009
Abstract: Background: In 2008, the catheter associated urinary tract infection (CAUTI) rate at King Fahad Medical City (KFMC) was 3.8/1000 urinary catheter days with some variability between departments. KFMC is the newest tertiary, referral and teaching hospital with 1100 beds in Riyadh, Saudi Arabia. The Infection Control Department at KFMC decided to implement a quality improvement project by applying the bladder bundle in our general ward (Non-ICU) using the model of National Health Service (NHS) hospitals in England even though there was good evidence supporting this infection control practice only in ICU patients[1][2]. Our objective was to decrease CAUTI in two non-ICU units by at least 50% in one year. Study design: This was a prospective interventional quality improvement project aiming to decrease CAUTI in two non-ICU inpatient units with a total of193 beds including children and adult patients. Our intervention includes insertion and maintenance components. Results: CAUTI decreased significantly in both departments from 23 infections in2008 (Rate: 5.03/1000 CDs) to 12 infections in 2009 (Rate: 1.92/1000 CDs) (P= 0.0001); in RH (Rehabilitation hospital) from 18 in 2008 (Rate: 4/1000 CDs) to 11 infections in 2009 (Rate: 0.36/1000CDs) (P< 0.0001) and in NSI (National Neuroscience Institute) from 5 in 2008 (Rate: 5.42/1000
Predictors for Dilated Aorta in Repaired and Unrepaired Tetralogy of Fallot  [PDF]
Khaled R. Abd El Meguid, Hesham B. Mahmoud, Mostafa M. Mohammad
World Journal of Cardiovascular Diseases (WJCD) , 2015, DOI: 10.4236/wjcd.2015.58027
Abstract: Aortic root pathology has been described in patients with Tetralogy of Fallot, although the most common reason for repeat surgery in the adult after TOF repair relates to problems in the right ventricular outflow tract, the aortic root is often forgotten. Objective: We sought to determine those patients with known Fallot tetrallogy at risk for progressive dilatation of the thoracic aorta and explore the common predictors present in this patient group. Methods and Results: A multicenter observational study which enrolled 100 patients (50 surgically repaired and 50 before surgical repair of TOF) with standardized reassessment of echocardiographic parameters and multislice CT angiography of the heart and great vessels data. The data were reviewed and analyzed according to the demographic, morphological, surgical and clinical details. We used standard nomograms and Z score for aortic root dimensions at the level of aortic annulus, sino-tubular junction and sinus of Valsalva based on body surface area. For surgically repaired patients, all the measured diameters across aortic annulus, STJ & sinus of Valsalva were larger in the dilated unrepaired group with mean & median of 24.63 (3.99) & 25 (15 - 35), 27.2 (4.26) & 27 (17 - 40), 35.97 (4.59) & 36 (24 - 45) mm respectively compared to a mean & median of 13.2 (2.62) & 13 (9 - 17), 14.53 (2.90) & 14 (10 - 19), 20.53 (3.40) & 21 (14 - 25) mm respectively in the not dilated unrepaired group with significant statistical difference (p value < 0.0001). Also Z score among unrepaired dilated TOF patients was larger in comparison to the non dilated unrepaired group with significant statistical difference (p value < 0.0001). For unrepaired patients, all the measured diameters across aortic annulus, STJ & sinus of Valsalva were larger in the dilated unrepaired group with mean & median of 24.63 (3.99) & 25 (15 - 35), 27.2 (4.26) & 27 (17 - 40), 35.97 (4.59) & 36 (24 - 45) mm respectively compared to a mean & median of 13.2 (2.62) & 13 (9 - 17), 14.53 (2.90) & 14 (10 - 19), 20.53 (3.40) & 21 (14 - 25) mm respectively in the not dilated unrepaired group with significant statistical difference (p value < 0.0001). Also Z score among unrepaired dilated TOF patients at the level of annulus, STJ & sinus of Valsalva was larger in comparison to the non dilated unrepaired group with significant statistical difference (p value < 0.0001). Conclusions: The first important finding of this study is the occurrence of significant aortic root dilatation
Fundamentals of Direct Inverse CFD Modeling to Detect Air Pollution Sources in Urban Areas  [PDF]
Mahmoud Bady
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2013, DOI: 10.4236/cweee.2013.22004

This paper presents the fundamentals of direct inverse modeling using CFD simulations to detect air pollution sources in urban areas. Generally, there are four techniques used for detecting pollution sources: the analytical technique, the optimization technique, the probabilistic technique, and the direct technique. The study discusses the potentialities and limits of each technique, where the direct inverse technique is focused. Two examples of applying the direct inverse technique in detecting pollution source are introduced. The difficulties of applying the direct inverse technique are investigated. The study reveals that the direct technique is a promising tool for detecting air pollution source in urban environments. However, more efforts are still needed to overcome the difficulties explained in the study.

Wavelet Density Estimation of Censoring Data and Evaluate of Mean Integral Square Error with Convergence Ratio and Empirical Distribution of Given Estimator  [PDF]
Mahmoud Afshari
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.513200
Abstract: Wavelet has rapid development in the current mathematics new areas. It also has a double meaning of theory and application. In signal and image compression, signal analysis, engineering technology has a wide range of applications. In this paper, we use wavelet method, for estimating the density function for censoring data. We evaluate the mean integrated squared error, convergence ratio of given estimator. Also, we obtain empirical distribution of given estimator and verify the conclusion by two simulation examples.
Page 1 /146453
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.