OALib Journal期刊

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匹配条件: “ Mohamed Yousef A.” ,找到相关结果约468055条。
Effect of DNA Contaminants on Calcium Phosphate-Based DNA Delivery and Gene Expression
Mohamed A. El-Mogy,Yousef Haj-Ahmad
Journal of Biotech Research , 2012,
Abstract: Plasmid DNA is widely used to deliver genes into mammalian cells for the construction of new cell lines, gene therapy and gene expression studies. During DNA preparation, various contaminants can be introduced and reduce its delivery efficiency and create mutations that decrease the expression level of the delivered genes. We evaluated the effect of different plasmid DNA contaminants on calcium phosphate-based transfection efficiency as well as gene expression in Chinese hamster ovary cells. pCMVβ was transfected into the cells after spiking with five different contaminants conditions: ethanol, endotoxin, cesium chloride, ethidium bromide and the combination of the latter two contaminants. Transfection efficiencies were determined through the counting of the Lac-Z-expressing cells as well as quantitative PCR. The reversibility of the contaminant interaction with DNA was examined through cleaning of the spiked DNA followed by transfection. As concluded from our results, qPCR offers accurate measurement of transfection efficiency than the conventional Lac-Z activity assay. In general, all of the examined contaminants, with the exception of ethanol, have a significant negative effect on gene expression. While this effect is resulted from the reduced delivery in most of the used contaminants, ethidium bromide showed no significant decrease in delivery, indicating alternative mechanism for its negative effect on gene expression.
Assessment of Commercial Specific IgE Assay for Detection of Allergens in Allergic Patients  [PDF]
Mohamed Yousef Attia, Hesham Sanad Mohamed
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2013, DOI: 10.4236/jasmi.2013.32013

Allergy is a serious health problem throughout the world, affecting people of all ages. Allergic diseases such as asthma, rhinitis and atopic dermatitis are becoming an epidemic in our country, the cost of investigating these diseases is increasing and becoming expensively high. There are many ways to explore allergenic antibodies to assess the presence the amount of specific IgE as: Skin test (Prick), Specific IgE (ELISA), RAST Sp.IgE and Elimination Challenge method. Skin test produces pain, local and anaphylactic reaction and patient discomfort, other procedure with highly cost to patient. So, we have built up an evidence to use it in our allergy and immunology clinic has suitable cost for all patients based about for the other tests but it was very simple, accurate, cheap and does not produce any problems to patients. Our test depends on ELISA technique, it measures the quantitative amount of the following different allergens: As regard food allergens: Milk, Eggs, Banana, Maize, Fish, Chocolate, Wheat, Nuts, Strawberry, Shrimps, Spices, with drug as Aspirin. As regard inhalants as: House dust, Mite, Mixed Pollens, Mixed Moulds, Hay dust, Wool, Latex and Cat Hair. 150 allergic patient results of our test compared with specific IgE national kits (ELISA), Sp.IgE (RAST), Skin test and elimination challenge test. The statistical evaluation results as regard senistivity respectively: 88.9%, 89.6%, 91.2%, 71.4%, 93.1%. As regard specificity the results: 93.1%, 94.7%, 95.3%, 65.5%, 91.6%, the latter results showed that our test was in line with all tests. Our test was probably in food, drug and inhalant allergens, it can be also noted that the cheapest and most commercial technique was used, so as to be available immediately in standard laboratory and its reagents, plate and other requirements were prepared locally in our laboratory. Now it was applying successfully in allergy and immunology unit Ain Shams university hospitals in Egypt.

Evaluation of Handmade Extra-Corporeal Loop versus Metallic Clips in Securing the Appendicular Stump in Laparoscopic Appendicectomy  [PDF]
Mohamed Yousef A., Abdallah M. Taha, Asmaa Gaber R., Mahmoud Abdelhameid, Mohammed A. Omar, Mohamed Abdelshafy
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1103117
Introduction: Laparoscopic appendicectomy has gained popularity due to the advantages of minimal-access surgery. Inadequate closure of the appendix stump leads to intra-abdominal surgical site infection or even fecal fistula. The base of the appendix can be secured with endostapler, endoloops, metallic clips or intracorporeal ligature. Aim: To evaluate the handmade extra-corporeal loop versus endoclip in securing the base of the appendix in non-complicated acute appendicitis. Methods: During the period from April 2014 to February 2016, in South Valley University, Aswan University and Sohag University hospitals (these are tertiary hospitals), 400 laparoscopic appendicectomy patients were included in this prospective study. In total, 240 patients were female and the overall average age was 25.6 years old. Patients were divided into two equal groups (group L and group C): in group L, handmade extracorporeal loop was used to secure the base of the appendix, the metallic clip was used in group C. Results: The mean operative time was 49 min in group L and 35.4 min in group C (P < 0.05). The mean hospital stay was 2.07 days in group L and 2 days in group C, and this was not significant (P > 0.05). Complications varied between port- site wound infection and delayed intestinal sounds, fecal fistula and there were no statistically significant differences. Conclusion: Using extracorporeal handmade loop or the metallic clips to secure the appendicular stump is safe, feasible, easy and inexpensive methods. The loop takes a little more time in its preparation. Metallic clips are inappropriate for edematous wide base appendix.
Effect of Cu2+ Doping on Structural and Optical Properties of Synthetic Zn0.5CuxMg0.5-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) Nano-Ferrites  [PDF]
Badawi M. Ali, Mohamed A. Siddig, Yousef A. Alsabah, Abdelrahman A. Elbadawi, Abdalrawf I. Ahmed
Advances in Nanoparticles (ANP) , 2018, DOI: 10.4236/anp.2018.71001
Abstract: The samples of Zn0.5CuxMg0.5-xFe2O4 nanoparticle ferrites, with x= 0.0, 0.1, 0.2, 0.3, 0.4 were successfully synthesised. Structural and optical properties were investigated by X-ray Diffraction (XRD), Fourier Transform Infrared spectros-copy (FTIR) and UV-visible spectroscopy. The structural studies showed that all the samples prepared through the Co-precipitation method was a single phase of a face-cantered-Cubic (FCC) spinel symmetry structures with space group (SG): Fd-3m. In the series Zn0.5CuxMg0.5-xFe2O4, the lattice parameter was found to be 8.382 ? for x = 0 and was found to increase with copper con-centration. The grain size obtained from the XRD data analyses was found to be in the range of 15.97 to 28.33 nm. The increased in the grain size may be due to the large ionic radius of Mg2+ (0.86 ?) compared with Cu2+ (0.73 ?). The FTIR spectroscopy confirmed the formation of spinel ferrite and showed the characteristics absorption bands around 580, 1112, 1382, 1682, 1632 and 2920 cm-1. The energy band gap was calculated for samples were found to be in the range 4.04 to 4.67 eV.
Thermal stability of some metal-palmitate soaps which find various industrial applications
Fouda, M. F.R.,Yousef, Elham A.A.,Mohamed, S. S.,Shoeb, Zein E.
Grasas y Aceites , 2001,
Abstract: The soaps of alkaline earth's and transition elements and closed a da orbitals were prepared by the double decomposition method by the reaction between metallic salts and sodium palmitate. The thermal stability of these soaps was studied in order to throw the light on their suitability for using as catalysts or lubricants. The soaps of alkaline earth's were found to be more stable than transition and a da closed shell soaps. Se han preparado jabones de tierras alcalinas y elementos de transición y orbitales a da completos por el método de la descomposición doble mediante la reacción entre sales metálicas y palmitato sódico. La estabilidad térmica de estos jabones se estudio con el fin de arrojar luz sobre su idoneidad para su uso como catalizadores o lubricantes. Se encontró que los jabones de las tierras alcalinas son más estables que los de transición y que los jabones con la capa a da completa.
Primary gastric fundus tuberculosis in immunocompetent patient: a case report and literature review
Khan, Fahmi Yousef;AlAni, Ahmed;Al-Rikabi, Ammar;Mizrakhshi, A.;Osman, Mohamed El-Mudathir;
Brazilian Journal of Infectious Diseases , 2008, DOI: 10.1590/S1413-86702008000500020
Abstract: we report on a 29-year-old pakistani man who presented to the clinic with epigastric pain, of one-month duration. he did not report fever, cough, vomiting blood, passing black stools, loss of appetite or diarrhea. however, he had lost 7 kg since his symptoms had begun. clinical examination was unremarkable. laboratory results were within normal limits. an abdominal ct scan showed a mass with enhancement in the stomach. gastric endoscopy revealed an ulcerative mass in the fundus. an endoscopic-biopsy specimen revealed caseating granulomas with acid-fast bacilli. the patient was diagnosed to have primary gastric tuberculosis, and antituberculous medications were initiated. cultures of the gastric mass subsequently grew mycobacterium tuberculosis sensitive to isoniazid and rifampcin. follow-up after six months showed a good response to treatment; an upper gastrointestinal tract endoscopy after six months was normal.
Effect of Titanium Dioxide Nano Particles Incorporation on Mechanical and Physical Properties on Two Different Types of Acrylic Resin Denture Base  [PDF]
Mohamed Ashour Ahmed, M. El-Shennawy, Yousef M. Althomali, Adel A. Omar
World Journal of Nano Science and Engineering (WJNSE) , 2016, DOI: 10.4236/wjnse.2016.63011
Abstract: The aim of this study is to clarify the effect of different concentrations of titanium dioxide nanoparticles (Nps) on the properties of two types of heat polymerized acrylic resin. The tested parameters were flexural strength, impact strength, and microhardness. The two types of acrylic resin used in this study were conventional unmodified (Implacryl, Vertex) and high impact heat polymerized acrylic resin (Vertex-Dental, Netherlands). Both types of acrylic resin were modified by using 1% and 5% TiO2 Nps powder. Specimen’s dimensions were prepared according to the American Dental Association Specification No. 12. Three types of specimens were prepared: 1) flexural strength specimens 50 mm × 10 (±0.2) mm × 3 (±0.2) mm, 2) impact strength test specimens 60 mm × 6.0 mm × 4.0 mm, 3) microhardnesss specimens 25 mm × 10 mm × 3 (±0.2) mm. For each test 6 groups were prepared (each group containing 5 samples). Thirty specimens were prepared in each of the three tests, amounting to a total number of 90 specimens. Mechanical properties such as flexural strength (FS), impact strength and microhardness of the above mentioned specimens were determined using universal testing machine, Izod pendulum impact testing machine and Vickers microhardness tester, respectively. ISO Specification No. 1567 was followed in microhardness test. The data was collected and statistically analyzed. Flexural strength considerably decreased by increasing TiO2 concentration in both types of acrylic resin. Impact strength of the conventional acrylic resin modified by 1% of additives significantly increased. The microhardness is significantly increased by addition of 5% of TiO2 Nps. The Incorporation of TiO2 nanoparticles into acrylic resins can adversely affect its flexural strength. Meanwhile, the impact strength can be modified by small percentage of additives (abt. 1%). This effect is directly correlated with the concentration of nanoparticles. On the other hand, concentrations of TiO2 Nps (abt. 5%) positively affect the microhardness of both types of acrylic resin used in the present study.
A Modified Limberg Flap versus Z Plasty Flap Technique in Management of Recurrent Pilonidal Disease: A Comparative Prospective Study  [PDF]
Asmaa Gaber R., Mohamed Yousef A., Mohamed Abdel Shafy Mohamed, Abd-El-Aal A. Saleem, Hassan A. Abdallah, Hamdy M. Husein
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104715
Background: There are controversies about the etiology and management of recurrent pilonidal sinus. The numbers of techniques are testament in treating pilonidal sinus (PNS) and no single procedure is superior in all aspects. Aim of the study: The aim of this study was to compare two operative procedures (modified Limberg flap versus Z plasty flap) in management of recurrent pilonidal sinus, regarding their complications including recurrences of the disease, morbidity, hospital stay, day off work and postoperative complications. Patients and methods: This is comparative prospective study between modified Limberg flap and Z plasty flap in treatment of recurrent pilonidal sinus. 30 patients were divided into 2 groups: Group (1) treated with modified Limberg flap and group (2) treated with Z plasty, and we followed up the patients in both groups for postoperative complications, hospital stay, day off work, recurrences, patients satisfactions. Results: Operative time, hospital stay duration, complete wound healing was longer in group (2) Z plasty group. Mobilization was early in MLF group than Z plasty group (1 day versus 2 days). Time to return to work, it was 14 (12 - 16) days in MLF groups and 18 (15 - 22) in Z plasty group (p < 0.001). Infection occurred only in one in MLF group (1) and 2 patients in Z plasty group (2). The mean time for complete healing of the wound after Modified Limberg flap group (1) was 16 ± 4.2 days while in Z plasty group (2) it was 22 ± 6.8 days. Satisfaction score was better in MLF group (1). Recurrence hadn’t occurred in any of the patients included in this study during the follow-up period. Conclusion: Both of modified Limberg flap and Z-plasty technique are used to cause flattening of the natal cleft, thus reducing local recurrence rates. So, we recommend use of flap technique for recurrent pilonidal sinus patients; modified Limberg transposition flap is better than Z plasty flap, because of the less hospital stay time, early return to work, and cosmetically more accepted as it has less postoperative complications. Also Z plasty flap has a major limitation as it is difficult to apply if there is a wide defect in the horizontal axis.
Neural Network Predictive Control Based Power System Stabilizer
Ali Mohamed Yousef
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: The present study investigates the power system stabilizer based on neural predictive control for improving power system dynamic performance over a wide range of operating conditions. In this study a design and application of the Neural Network Model Predictive Controller (NN-MPC) on a simple power system composed of a synchronous generator connected to an infinite bus through a transmission line is proposed. The synchronous machine is represented in detail, taking into account the effect of the machine saliency and the damper winding. Neural network model predictive control combines reliable prediction of neural network model with excellent performance of model predictive control using nonlinear Levenberg-Marquardt optimization. This control system is used the rotor speed deviation as a feedback signal. Furthermore, the using performance system of the proposed controller is compared with the system performance using conventional one (PID controller) through simulation studies. Digital simulation has been carried out in order to validate the effectiveness proposed NN-MPC power system stabilizer for achieving excellent performance. The results demonstrate that the effectiveness and superiority of the proposed controller in terms of fast response and small settling time.
Diagnostic Utility of Transbronchial Needle Aspiration in Malignant Endobronchial Lesions: Relevance to Lesions’ Characteristics
Sherif A. A. Mohamed,Yousef Ahmed,Khaled Hussein,Nashwa M. A. Abd El-Aziz,Yasser Gamal
Journal of Respiratory Medicine , 2013, DOI: 10.1155/2013/756483
Abstract: In this prospective study, we aimed to report our experience with the diagnostic utility of transbronchial needle aspiration (TBNA) in patients with malignant endobronchial lesions detected during routine bronchoscopy. Ninety-four patients were enrolled. TBNA and conventional diagnostic techniques (CDTs: forceps biopsy, brushing, and washing) were performed in all patients. Endobronchial lesions were classified into exophytic mass lesions (EMLs), submucosal disease (SD), and peribronchial disease (PD). The diagnostic yields of TBNA and CDT alone and together were compared according to the lesions’ types, histopathology, and locations. During 3-year period, the addition of TBNA to CDT improved bronchoscopic sensitivity from 70.2% to 94.7% in all lesion types. Addition of TBNA to CDT increased the diagnostic success from 74% to 95% and from 50% to 94% in NSCLC and SCLC, respectively. The diagnostic success was increased in all localizations by the addition of TBNA to CDT, particularly for lesions located at the trachea, main bronchi, and upper lobes. We conclude that the addition of TBNA to CDT increases the diagnostic yield in patients with visible malignant endobronchial lesions, particularly in peribronchial disease, and improves the diagnostic yield of bronchoscopy, in both NSCLC and SCLC and in all bronchoscopic locations, particularly in central and upper lobar lesions. 1. Introduction Transbronchial needle aspiration (TBNA) is a modality that allows the bronchoscopist to sample tissue from the deeper submucosa as well as from the close extraluminal areas of the endobronchial tree. TBNA is a beneficial, safe, and minimally invasive technique that was proved to be useful in the diagnosis and staging of lung cancer [1]. Previously, the utility of TBNA was restricted to mediastinal lymph node and extrabronchial lesion sampling. Its use has been expanded to complement conventional diagnostic techniques (CDTs) such as bronchial washing (BW), bronchial brushing (BB), and forceps biopsy (FB) in the diagnosis of endobronchial lung cancer [2]. However, only few studies [2–7] had addressed the diagnostic utility of TBNA in visible endobronchial lung cancer. Moreover, despite that TBNA proved cost-effective diagnostic utility in visible malignant endobronchial lesions [8], studies evaluating that utility in developing countries are still lacking. Lung cancer may present either as a parenchymal lesion or as endobronchial disease. The latter may manifest as an exophytic mass lesion (EML), submucosal infiltration (submucosal disease, SD), or extrinsic compression

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