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Search Results: 1 - 10 of 34018 matches for " Ahmed Mohamed Ali "
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Influence of Reaction Conditions on Sol-Gel Process Producing SiO2 and SiO2-P2O5 Gel and Glass  [PDF]
Amany Mohamed Elnahrawy, Ahmed Ibrahim Ali
New Journal of Glass and Ceramics (NJGC) , 2014, DOI: 10.4236/njgc.2014.42006
Abstract: The effect of H2O and the slow thermal annealing on the properties of pure silica (SiO2) and phosphosilicate (SiO2-P2O5) gel-glasses are presented. The monolithic samples have been prepared via sol-gel process using tetraethorthosilicate (TEOS), Si(C2H5O)4 and Triethylphosphate (TEP) (C2H5O)3P(O) as SiO2 and P2O5 precursors. Phosphate incorporates into the silicate network by substituting Si atoms and consequently, we observed changes in structural and spectroscopic properties for these systems. The structures of prepared samples were examined by observed weight loss, XRD and FTIR. It has been found that in the structure of pure silica and phosphosilicate glasses there are formed domains characterized by certain degree of ordering of the units present in their composition, while the structure of pure silica is still amorphous of these glasses. The changing character of domains structure may be the reason of different chemical activities of phosphosilicate glass.
Evaluating the evolving evidence: The challenges of molecular-targeted therapy in management of gastric cancer  [PDF]
Yasar Albushra Abdul Rahiem Ahmed, Mohamed Ali
Open Journal of Gastroenterology (OJGas) , 2014, DOI: 10.4236/ojgas.2014.41002

Over the past decade, a multitude of molecular targeted agents have been explored in the treatment of advanced metastatic gastric. Recent advances in molecular signaling pathways that are dysregulated in gastric cancer lead to the development of new targeted therapies for the treatment of advanced and metastatic gastric cancer. The addition of trastuzumab to first-line chemotherapy is now a standard of care for the treatment of Human epidermal growth factor receptor (HER2-) positive advanced or metastatic disease, and other HER2-targeted therapies are in late-stage clinical development. Findings from recent major clinical trials provide important insight into the future of metastatic gastric cancer management, which may include the use of anti-angiogenesis, Mesenchymal epithelial transition factor (MET) and Hedgehog Pathways Inhibitortherapy across multiple treatment lines, in the salvage setting, and as part of novel regimens in combination with other targeted agents.

Post-Aneurysmal Subarachnoid Hemorrhage Vasospasm, Clinical Correlation between the Aneurysm Site and Clinical Vasospasm  [PDF]
Ahmed Ali, Mohamed A.R. Soliman
Open Journal of Modern Neurosurgery (OJMN) , 2018, DOI: 10.4236/ojmn.2018.83025
Abstract: Background: Intracranial vasospasm is a common complication following subarachnoid hemorrhage (SAH). The radiographic vasospasm can reach up to 90% of aneurysmal SAH. Materials and Methods: 139 consecutive patients admitted to Cairo University Hospitals from June 2013 to September 2014 with SAH who had been enrolled in a retrospective controlled study were analyzed retrospectively for the occurrence of vasospasm. The data collected from the charts of Cairo University Hospitals were the patient’s demographics, clinical presentation, aneurysm location, treatment modality, and Glasgow Outcome Scale (GOS) scores. We excluded 24 patients with nonaneurysmal SAH, 3 internal carotid artery (ICA) aneurysms, 7 with multiple aneurysms and 4 patients died before treatment. Results: 72 males and 29 females were included in the study, mean age 53.5 ± 11.5 years. Twelve patients had aneurysms located in the vertebral artery group, 24 had middle cerebral artery aneurysms, 11 had pericallosal aneurysms, and 54 patients had anterior communicating artery (ACoA) complex aneurysms. Radiographic vasospasm occurred in 62.4% with the highest incidence (75.9%) at the ACoA complex group. Symptomatic vasospasm occurred in 48.5% with the highest incidence (63%) at the anterior communicating artery complex aneurysm location. The mean GOS at 6 months follow-up was 4.2. The worse GOS was found in the vertebral artery (VA) aneurysm group with a mean of 3.75. Conclusion: Aneurysms of the anterior communicating artery complex group have a greater risk of both radiographic and clinical vasospasm. Also, the worse 6 months follow-up GOS when an aneurysm was located in the VA group.
Prognostic Value of Retinal Nerve Fiber Layer and Ganglion Cell Complex after Optic Chiasmal Decompression  [PDF]
Shaymaa Hassan Salah, Ahmed Mohamed Ali
Open Journal of Modern Neurosurgery (OJMN) , 2019, DOI: 10.4236/ojmn.2019.91004
Abstract: This paper is an attempt to ascertain the role of the optical coherence tomography by measuring the retinal nerve fiber layer thickness and ganglion cell complex area to predict postoperative visual outcome after chiasmal decompression. 16 eyes scheduled for chiasmal decompression surgery were assessed before and 3 months after surgery with standard automated perimetry and OCT (optical coherence tomography). Preoperative RNFL (retinal nerve fibre layer) thickness and GCC (ganglion cell complex) area were compared with 20 normal control eyes. 13 cases were operated by microscopic assisted endoscopic endonasal transsphenoidal approach; the remaining 3 cases were operated transcranially. Spearman’s correlation analysis was used to evaluate the relationship between preoperative RNFL thickness, GCC area, postoperative mean deviation and temporal visual field sensitivity (1/Lambert). Preoperative measurements of RNFL thickness and all GCC area were significantly reduced in the patients compared with normal control. 3 months postoperative evaluation showed improvement of the visual field, but reduction in global and sectorial RNFL thickness except for nasal sector. Moreover, absolute postoperative (not pre-post change) visual field parameters were significantly correlated to preoperative RNFL (P = 0.00399 for mean deviation, P = 0.0023 for temporal sensitivity), GCC thickness (P = 0.00736 for mean deviation, P = 0.0469 for temporal sensitivity), with FLV (focal loss value) (P = 0.0012 for mean deviation, P = 0.0021 for temporal sensitivity) showed a higher correlation. Reduced RNFL thickness mainly, and GCC area minimally, were associated with the worst visual field outcome. FLV is a new prognostic value.
Numerical Calculations of Some Plasma Parameters of the Capacitively Coupled RF Discharge  [PDF]
Mohamed Ali Hassouba, Ahmed Rida Galaly, Usama Mohamed Rashed
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.58070

Numerical calculations by using a self-consistent model of the collisional sheath for the capacitively coupled RF discharge are our target. The results indicated that, at high pressure, the ohmic heating is usually the dominant heating mechanism in the discharge. The power dissipated in the sheath is calculated and compared with the measured data. Moreover, we indicated that, when the gas pressure is increased, the calculated dissipated power is decreased also while the measured input RF power is increased. Furthermore the sheath thickness of the capacitively coupled discharge is calculated and in the same order of the electron oscillation amplitude in the RF field, while the ionization mean free path is shorter than it.

Treatment of Resistant Clubfoot with Soft Tissue Release and Alkhooly External Fixator  [PDF]
Ali Zein A. A. Al-Khooly, Mohamed Ali Ahmed Mohamed, Ebrahim El-Hawary Ali
Open Journal of Orthopedics (OJO) , 2013, DOI: 10.4236/ojo.2013.37058

After the first research with this technique done by the first author, ten operations on the foot and ankle were performed on five patients (two boys and three girls) suffering from severe club foot deformity all with bilateral foot affection. Their ages ranged from five to fourteen years. All of them were treated by soft tissue release, skin flap (rotational flap), supplemented with Alkhooly external fixator. The follow up period ranged from two to seven years. The results according to Mittal (1987) [1] were excellent in eight feet (80%) and good in two feet (20%).



Transabdominal Pre-Peritoneal Mesh for Inguinal Hernia Repair with External Fixation versus Mesh Stapling  [PDF]
Mohamed Abdelhamid, Ahmed Mohamed Sadat, Ayman Refaat Abdelhaseeb, Tamer Mohamed Nabil, Mohamed Salah Abdelbasset, Amro Mohamed Ali Bechet, Hesham Ahmed Nafady, Kalid Ahmed Shawky
Surgical Science (SS) , 2013, DOI: 10.4236/ss.2013.411100

Background: It is unknown whether stapling the mesh affects recurrence rate, incidence of neuralgia, and port-site hernia. We chose to fix it to the exterior reducing port size, cost and pain, at the same comparing this with traditional mesh stapling. Methods: We conducted a prospective trial for laparoscopic TAPP inguinal hernia repair on 120 patients in which we fixed the mesh to the anterior abdominal wall using either two prolene threads that passed to the exterior and tied in place or traditional mesh stapling. Results: The operative time is ranged from 35 to 70 minutes for external fixation, 30 to 60 minutes for mesh stapling, and 4 to 51 months for follow-up, and no recurrence occurred in both groups during the procedure. Two cases with post TAPP pain in mesh stapling patients are discussed with reduction of the cost and port size in external fixation patients. Conclusion: It is not necessary to secure the mesh during laparoscopic TAPP inguinal hernia repair from the interior and it is fixed only to the exterior allowing a reduction in size of the ports and considerable reduction in cost with elimination of TAPP associated post operative pain.

Evaluation of the Environmental, Social Effects for the Egyptian National Railways Restructuring  [PDF]
Mahmoud Ahmed Mousa Ali, Mohamed Abdelnaby El Sayed
Journal of Transportation Technologies (JTTs) , 2015, DOI: 10.4236/jtts.2015.51003
Abstract: This paper presents the main findings of the environmental and social impact assessment (ESIA) for the Egyptian national railways restructuring. This paper consists of the two parts: 1) modernizing the signaling system on the Arab El Raml-Alexandria Line and creating a Central Traffic Management Center in Tanta; and 2) renewing 200 km of track in Lower and Upper Egypt. The purpose of this evaluation is to identify and examine the potential socio-cultural, economic, and physical impacts of the railway restructuring, and propose measures to mitigate its adverse impacts, and develop plans for managing and monitoring the environmental aspects of the railway restructuring. This paper describes outlines of the environmental and social sensitivities of the railway restructuring area, potentially significant impacts of the proposed project and plans for their mitigation. Detailed information on the environmental and socio economic settings of the railway restructuring, components and activities of the proposed project and the results of the environmental and social impact assessment studies are presented in the body of the paper.
Random Attractors for Stochastic Reaction-Diffusion Equations with Distribution Derivatives on Unbounded Domains  [PDF]
Eshag Mohamed Ahmed, Ali Dafallah Abdelmajid, Ling Xu, Qiaozhen Ma
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.610159
Abstract: In this paper, we prove the existence of random attractors for a stochastic reaction-diffusion equation with distribution derivatives on unbounded domains. The nonlinearity is dissipative for large values of the state and the stochastic nature of the equation appears spatially distributed temporal white noise. The stochastic reaction-diffusion equation is recast as a continuous random dynamical system and asymptotic compactness for this demonstrated by using uniform estimates far-field values of solutions. The results are new and appear to be optimal.
The Influence of Zn2+ Ions Substitution on the Microstructure and Transport Properties of Mn-Zn Nanoferrites  [PDF]
Mohamed Ali Ahmed, Kasim El-Sayed Rady, Kamel Mohamed El-Shokrofy, Ahmed Abo Arais, Mohamed Said Shams
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.513095
Abstract: The effect of Zn2+ ions on the microstructure and electrical properties of Mn1-xZnxFe2O4 (0.0 ≤ x ≤ 0.5 in steps of 0.1) through a solid state reaction has been investigated. The structural properties have been investigated using X-ray diffraction (XRD) technique. The XRD analysis confirms that all samples are in a single-phase cubic spinel structure. The experimental lattice parameter (aexp) was decreased with increasing Zn2+ ions substitution due to the smaller ionic radius of zinc content. The crystallite size (t) of samples was estimated by Scherrer’s formula and found in the range (90 - 115 nm). Dc electrical resistivity and Seebeck voltage coefficients were measured as a function of temperature using the two probe methods. The temperature variation of resistivity exhibits two breaks, each break referring to a change in the activation energy. The Curie temperature estimated from dc resistivity measurement decreases with increasing Zn2+ ions. Seebeck voltage coefficient measurements reveal n-type conduction for all samples.
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