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Search Results: 1 - 10 of 401341 matches for " Magdy M. M. Elnashar "
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Review Article: Immobilized Molecules Using Biomaterials and Nanobiotechnology  [PDF]
Magdy M. M. Elnashar
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2010, DOI: 10.4236/jbnb.2010.11008
Abstract: Immobilized molecules using biomaterials and nanobiotechnology is a very interesting topic that touching almost all aspects of our life. It uses the sciences of biology, chemistry, physics, materials engineering and computer science to develop instruments and products that are at the cutting edge of some of today’s most promising scientific frontiers. In this review article, the author based on his experience in this arena has tried to focus on some of the supports for im-mobilization; the most important molecules to be immobilized such as DNA, cells, enzymes, metals, polysaccharides, etc and their applications in medicine, food, drug, water treatment, energy and even in aerospace. He specified a special section on what is new in the arena of supports and technologies used in enzyme immobilization and finally a recommendation by the author for future work with a special attention to up-to-date references.
Theory of Combined Seepage Applied to Dewatering Systems  [PDF]
Magdy M. Aboelela
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.87060
Abstract: In the present study, an analytical solution is presented to solve the problem of combined seepage, under a sheet piling cofferdam, applied to dewatering systems. Existence of the sheet pile creates a confined seepage followed by an unconfined seepage in the same field, which presents a combined seepage problem. Two equations were developed to analyze the combined seepage underneath a sheet piling wall. Using such equations, both the maximum height of the free surface just behind the sheet piling cofferdam (Ho) and the quantity of seepage discharge to be pumped out from the construction site (q) can be determined. The main parameters affecting the combined seepage characteristics underneath a sheet piling wall are: The depth of permeable foundation layer (T), the horizontal distance behind the sheet pile (X), the depth of excavation in the construction site (D), the embedded depth of sheet pile (S), the retained water head (H1), the accumulated seepage water depth (H2), and the side slope factor of excavation line (M). Study showed that, the above parameters have a great effect on the combined seepage, but with different extents.
Control of Seepage through Earth Dams Based on Pervious Foundation Using Toe Drainage Systems  [PDF]
Magdy M. Aboelela
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.812090
Abstract: Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h3), and the coordinates of the free surface (hx). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (Hd) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.
Synthesis and Biological Activity of Drug Delivery System Based on Chitosan Nanocapsules  [PDF]
Mohamed Gouda, Usama Elayaan, Magdy M. Youssef
Advances in Nanoparticles (ANP) , 2014, DOI: 10.4236/anp.2014.34019
Abstract: Chitosan nanocapsules containing naproxen as an active ingredient were synthesized by ionic gelation method in presence of polyanion tripolyphosphate as a crosslinker. The morphology and diameter of the prepared chitosan nanoparticles was characterized using scanning electron microscopy and transition electron microscopy. Different factors affecting on the size diameter of chitosan nanoparticles such as stirring time and temperature, pH values as well as chitosan concentration were studied. Different factors affecting on the immobilization of naproxen into chitosan nanoparticles such as time, temperature and pH values were optimized. Synthesized naproxen/chitosan nanocapsules were assessed against both Gram positive bacterial strain such as Bacillus subtilis and Staphylococcus aureus and Gram negative bacterial strain such as Pseudomonas aeruginosa and Escherichia coli. Also, the antifungal activity of the naproxen/chitosan nanocapsules against Saccharomyces cerevisiae was demonstrated. Super oxide dismutase like activity of naproxen/chitosan nanocapsules will be determined.
Dielectric Behavior of Some Vinyl Polymers/Montmorillonite Nanocomposites on the Way to Apply Them as Semiconducting Materials  [PDF]
Amal Amin, Eman H. Ahmed, Magdy W. Sabaa, Magdy M. H. Ayoub, Inas K. Battisha
Open Journal of Organic Polymer Materials (OJOPM) , 2013, DOI: 10.4236/ojopm.2013.33012
Abstract:

Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the formation of such polymeric nanocomposites. Their dielectric properties were extensively studied to invest them in the a.c. power applications. Several dielectric parameters such as dielectric constant loss (ε\") and a.c. conductivity (σ) were measured at both different frequencies (0.1 Hz to 100 KHz) and temperature ranged from (20 to 90). From the dielectric results, it was realized that the dielectric a.c. conductivity was enhanced by increasing the temperature for the four prepared polymer nanocomposites.

Evaluating the Role of Measuring the Perineal Length as a Predictor of Progress of Labor and Obstetrical Trauma  [PDF]
Tarek A. Farghaly, Omar M. Shaaban, Ahmed F. Amen, Hossam T. Salem, Ihab Elnashar, Ahmad A. Abdelaleem, Esraa Badran
Open Journal of Obstetrics and Gynecology (OJOG) , 2017, DOI: 10.4236/ojog.2017.74048
Abstract: Objective: Evaluating the effect of perineal length on the duration of the second stage of labor, the mode of delivery, the need for episiotomy and the possibility of perineal and vaginal tears needing repair. Participants and Methods: It is a prospective hospital-based observational study done on 483 parturient women in a university hospital. Personal, medical and obstetric data together with the measurement of perineal length were recorded in the first stage of labor. We followed up the progress of labor until delivery. Regression models were used to consider possible risk factors of episiotomy or tears needed repair. Results: The mean duration of the second stage of labor was significantly longer among women with a perineum of ≥4 cm length when compared with those with a perineal length of <4 cm (36.7 ± 13.05 vs. 26.9 ± 10.4 minutes; respectively). Regression analysis of possible risk factors showed that circumcised primigravida with long perineum (≥ 4 cm) are more liable to have episiotomy (OR (95%CI) 1.96 (1.1 - 3.5); 20.9 (11.1 - 39.5); 4.8 (2.5 - 9.2); respectively). Tears needed to repair are however, more common in circumcised women with short perineum (<4 cm) who delivered without episiotomy (OR (95%CI) 14.16 (8.1 - 24.9); 4.54 (1.5 - 14) respectively. Conclusion: Longer perineum is associated with increase in the duration of the second stage of labor. Obstetricians should expect the need of episiotomy when confronted with circumcised primigravida with long perineum. However, if the perineum is short they should not be deceived, short perineum is more probably torn.
Efficiency of Selenium Ion Inclusion into Common Carp (Cyprinus carpio L) Diets
Magdy M. Gaber
Journal of Fisheries International , 2012,
Abstract: Efficiency has been investigated of the increase diets nutritional value by adding selenium as microelement into diets Common carp fingerlings were studied using aquarium and cement tanks systems, which allowed feeding and continues measurement of growth parameters. In experiment 150 fingerlings each weighing approximately 7.5 0.23 g was carried out in aquarium and fed either normal diet (A. group) or diets supplemented with 0.08, 0.16, 0.32 and 0.64 mg kg 1 of sodium selenite. In experiment 360 juvenile common carp, average weight 26.9 1.38 g was carried out in cement tanks and fed as in experiment. When selenium added to the diets and fed to the fish caused a significant increase in weight gain and carp fingerlings growth rate was accelerated by 18-22% feed expenditure out by 17-18% as compared to the control diet. There are significant differences in survival rate were found between treatments, indicating that diets are likely to be responsible for increased survival rate, observed in fish fed diet supplemented with 0.24 and 0.32 mg kg 1 Na2SeO3.5H2O. The results of this study indicated that a diet supplemented, 0.16 and 0.32 mg kg 1 of sodium selenite is important for growth and survival of common carp.
Cloning and Characterization of New emm Allele of Streprococcus pyogenes Strains Isolated in Kingdom of Saudi Arabia
Magdy M. Mohamed
Pakistan Journal of Biological Sciences , 2006,
Abstract: In the present study, 39 isolates of erythromycin-resistant group A Streptococcus (GAS) isolated in the kingdom of Saudi Arabia from 2003 to 2004 were characterized by using phenotypic and genotypic methods. Most strains (94.9%) had similar or highly related pulsed-field gel electrophoresis profiles to different nine emm types previously documented. In which, type emm1 was the most prevalent M type in KSA representing 20.5% of total isolates, followed by emm3 (15.4%) typing. Two new emm sequence types were identified among GAS strains designated SA15 and SA37. The type SA15 carried two resistant mefA and ermTR genes accounted for 6.3% (1/16) and 50.0% (1/2), respectively. Entire fragment of SA15 was sequenced and expressed in expression vector to be used as a tool for vaccine preparation in this area. This report provides information on new emm sequence types firstly detected in KSA GAS isolates as a vaccine candidate antigen in this geographic area which not extensively surveyed, also it contributes to a better understanding of the local and global dynamics of GAS populations and the epidemiological aspects of GAS infections occurring in KSA.
Molecular Characterization and Immunogentic Properties of a Group 3 Membrane Protein Isolated from B. abortus Infection
Magdy M. Mohamed
Journal of Biological Sciences , 2007,
Abstract: This study was conducted to evaluate the immunogenicity and protective efficacy of B. abortus protein antigen. A gene that encode 0.85 kbp was isolated from B. abortus genome λgt11 expression library by probing with a Polled Human Abs (PHAbs) infected with B. abortus or B. melitensis. Sequence analysis of the cloned gene revealed the presence of an Open Reading Frame (ORF) of 259 amino acids encoding for a protein with calculated molecular weight of 23 kDa (Bp23). The predicted amino acid sequences of this gene shows 83% similarity with B. abortus outer membrane 26 kDa protein (Omp26) previously sequenced. The recombinant B. abortus protein was identified by human sera infected with either B. abortus or B. melitensis, but not healthy persons as shown by Western blotting. Therefore, the availability of this recombinant protein and the identification of the antigenic determinant recognized by human Ab will allow the evaluation of its potential protective activity for the development of subcellular vaccines against brucellosis. Moreover, the use of this recombinant protein in Western blotting allowed differentiation between vaccinated from naturally infected camels. Hyperimmune rabbit serum against Bp23 recombinant protein could detect naturally infected animals with different specificities, whereas represented in camels (100%), cows (54%) and sheep (33%), but not detected at all in brucellosis free camels. These data indicated that the new isolated Bp23 recombinant protein might be of value as a vaccine candidate for treatment of human brucellosis and as an antigen for serological diagnosis of brucellosis in different animals as well.
Challenges and Opportunities of US and Arab Collaborations in Health Services Research: A Case Study from Qatar
Maya M. Hammoud,Maha Elnashar,Huda Abdelrahim,Amal Khidir
Global Journal of Health Science , 2012, DOI: 10.5539/gjhs.v4n6p148
Abstract: Economic globalization and advances in technology have made it more feasible and even necessary to develop international research collaborations in global public health. Historically, collaborations in global research described in the literature have been mostly “North-South” collaborations in which the more developed “North” country works together with a developing “South” country to conduct research in the latter. This type of collaboration has for the most part, represented unequal partnership and rarely left behind a lasting impact. Recently, the opportunity for a new kind of international research partnership has emerged in which the host country has significant financial resources, but relatively limited expertise in research methodology or techniques and research implementation. This type of collaboration features a relative equalization of power between the international partners. The purpose of this paper is to describe the process of building a successful research collaboration between a team in the United States and a team in Qatar, a rich Arabic nation in Gulf. We present a case study that provides an overview of our own project focused on the development of a culturally and linguistically adapted health care quality instrument for Qatar, discussing many of the benefits and challenges we encountered during each phase of instrument development. We present recommendations for researchers seeking sustainable and equitable partnerships with the Arab World.
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