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The Effect of Board of Directors Characteristics on Firm’s Financial Performance: An Empirical Study on the Most Active Firms in the Egyptian Stock Exchange  [PDF]
Ashraf Mohamed Abdel Atty, Mohamed Moustafasoliman, Amr E. Youssef
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104993
Abstract:
This paper seeks examining the effect of Board of Directors Characteristics on firm’s financial performance in Egypt, using a sample of 50 more active Egyp-tian companies listed on the Egyptian Stock Exchange of the non-financial sector covering the period of three financial years from 2012 to 2017. Board of Directors Structure is represented by CEO Duality, Board Size, Board Meet-ings, Independence board members and Gender Diversity. Return on Assets (ROA), Return on Equity (ROE) and Tobin’s Q is used as a proxy for Firm fi-nancial Performance. In this research, correlation and regression analysis are used to examine the relationship between Corporate Governance and firm’s fi-nancial performance.
Ultra Sensitive Determination and Preconcentration of Cd2+, Cu2+ and Pb2+ after Multi-Walled Carbon Nanotubes Adsorption  [PDF]
Ashraf Mohamed Abdel-Lateef, Ramadan Abdel-Wahed Mohamed, Hazem Hassan Mahmoud
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2013, DOI: 10.4236/jasmi.2013.31002
Abstract:

Multi-Walled carbon nanotubes are used as preconcentrating probes for the quantitative determination of trace cadmium, copper and lead in environmental and biological sample using graphite Furnace Atomic Absorption Spectrometry and inductively coupled Plasma Optical Emission spectrometry. The method is based on the electrostatic interactions of positively charged Cd+, Cu+ and Pb+ with the negatively charged multi-walled carbon nanotubes (MWCNTs) for the preconcentration and isolation of analytes from sample solutions. Effective preconcentration of trace cadmium, copper and lead was achieved in a pH range of 5 - 7, 5 - 7 and 4 - 7, respectively. The retained cadmium, copper and lead were efficiently eluted with 0.3 mol·L-1 HCl for graphite Furnace Atomic Absorption Spectrometry determination. The multi-walled carbon nanotubes packed micro-column exhibited fairly fast kinetics for the adsorption of cadmium, copper and lead, permitting the use of high sample flow rates up to at least 3 mL·min-1 for the flow injection on micro-column preconcentration without the loss of the retention efficiency. The detection limits (3σ) were 0.03, 0.01 and 0.5 ng·mL-1 for Cd, Cu and Pb, respectively. The relative standard deviation under optimum condition is less than 2.9% (n = 10). The developed method was successfully applied to the determination of trace Cd, Cu and Pb in a variety of environmental and biological samples.

Organ Preservation in Bilharzial Bladder Cancer in Egypt: Single Institutional Experience  [PDF]
Hamza Abbas, Mohamed Abdel Aboziada, Mostafa Elsayed Abdalwanis, Mohamed Abdallah El-Gmal, Ahmed Mokhtar, Mohamed Ahmed Abo-Almagd, Farouk Morad Amr, Ashraf Elyamany
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.31008
Abstract: Background: Phase II study was conducted to evaluate bladder preservation protocol in Bilharzial and non Bilharzial invasive transitional cell carcinoma (TCC) bladder cancer using gemcitabine and conformal radiotherapy (RT). Methods: 30 TCC patients with good performance status and renal function subjected to maximum trans-urethral resection of bladder tumor (TURBT). Patients received 66 Gy/33 fractions/6.5 weeks with weekly gemcitabine 125 mg/m2. Evaluation was done after one month with cystoscopy and CT/MRI pelvis. Patients who had complete remission (CR) subjected for follow up and patients who had invasive bladder tumor subjected to radical cystectomy. Results: 24 patients had CR after one month evaluation. Stage 2 tumor, low grade, non Bilharzial and maximum TUR were the only prognostic factors. The treatment schedule was tolerable and was associated with infrequent incidence of moderate toxicity that was easily controlled without interruption of RT. Cystectomy free survival was 88% at a median follow up for 2 years. Conclusions: Gemcitabine and conformal RT after TURBT treatment could be an effective way to achieve a high response rate in the treatment of invasive TCC of the bladder with good tolerance. Organ preservation in Bilharzial bladder is still possible.
Evaluation of Surgical Outcome after Resection of Pancreatic Tumors, Our Experience in Mansoura Oncology Center, a Middle-Volume Center in Egypt  [PDF]
Nazem Shams, Mahmoud Mosbah, Mohammad Hegazy, Osama Hussein, Omar Farouk, Sameh Roshdy, Mohamed Tarek Hafez, Ashraf Khater, Khaled Abdel Wahab
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.35061
Abstract: Background: Pancreatic cancer is the fourth most common cause of cancer related deaths in the world. Surgical resection remains the only potentially curative treatment for adenocarcinoma of the pancreas; only 10% - 20% of patients are candidate for standard pancreatic resection. Objective: To evaluate perioperative mortality, morbidity and survival for patients underwent PD in middle-volume center. Patients and Methods: Sixty patients with pancreatic tumors were enrolled in this study for different surgical procedure according to type of tumors. Results: No early postoperative complications were observed in 60% of patients, whereas 40% of patients developed one or more complication, the median survival for this group was 12.3 months with standard deviation 3.8 months.
Thyroid Dysfunction in Patients with Systemic Connective Tissue Disease
Heba Sayed Assal,Ashraf Elsherbiny,Ahmed Alsayed,Mohamed Abdel Maaboud
Macedonian Journal of Medical Sciences , 2009,
Abstract: Background. Alterations in the circulating thyroid hormone concentrations constituting the euthyroid sick syndrome (ESS) are frequently associated with systemic non-thyroidal diseases such as systemic connective tissue disease (SCTD). Aim. To elucidate the pattern of thyroid dysfunction in patients with SCTD. Subjects and Methods. Thirty patients with systemic lupus erythematosus (SLE) and thirty rheumatoid arthritis (RA) patients in addition to 30 healthy age- and sex- matched controls were recruited from the Internal Medicine Department of Ain- Shams University Hospital. Thyroid stimulating hormone (TSH), thyroid hormones including T3 and T4, antithyroglobulin antibodies (ATGAb), thyroid peroxidase antibodies (TPOAb), ESR, RF, ANA, LE cells and CRP were determined. Results. 46.6 percent of SLE patients showed thyroid dysfunction compared to 16.6% of RA (P<0.05). In SLE group, 20% had euthyroid sick syndrome, 16 % had hypothyroidism (10% subclinical and 6% overt), and 9% had hyperthyroidism (3% subclinical and 6% overt). However in RA, 13% had hypothyroidism (10% subclinical and 3% overt) and 3% had subclinical hyperthyroidism. TPOAb was found in 16% of SLE and 6% in RA patients. Also ATGAb was found in 6% of SLE and 30% in RA patients and 10% of controls, but the titers were higher in the patients. Conclusion. Thyroid dysfunction was common in patients with SCTD and they were associated with antithyroid antibodies.
Fabrication and characterization copper/diamond composites for heat sink application using powder metallurgy  [PDF]
Zeinab Abdel Hamid, Sayed F. Moustafa, Fatma A. Morsy, Nevien Abdel Atty khalifa, Fatma Abdel Mouez
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.311120
Abstract: Copper composites reinforced with diamond particles were fabricated by the powder metallurgical technique. Copper matrix and diamond powders were mixed mechanically, cold com- pacted at 100 bar then sintered at 900?C. The prepared powders and sintered copper/diamond composites were investigated using X-ray diffraction (XRD) and scanning electron microscope equipped with an energy dispersive X-ray analysis (SEM/EDS). The effect of diamond contents in the Cu/diamond composite on the different properties of the composite was studied. On fracture surfaces of the Cu/uncoated diamond composites, it was found that there is a very weak bonding between diamonds and pure copper matrix. In order to improve the bonding strength between copper and the reinforcement, diamond particles were electroless coated with NiWB alloy. The results show that coated diamond particles distribute uniformly in copper composite and the interface between diamond particles and Cu matrix is clear and well bonded due to the formation of a thin layer from WB2, Ni3B, and BC2 between Cu and diamond interfaces. The properties of the composites materials using coated powder, such as hardness, transverse rupture strength, thermal conductivity, and coefficient of thermal expansion (CTE) were exhibit greater values than that of the composites using uncoated diamond powder. Additionally, the results reveals that the maximum diamond incorporation was attained at 20 Vf%. Actually, Cu/20 Vf% coated diamond com- posite yields a high thermal conductivity of 430 W/mK along with a low coefficient of thermal expansion (CTE) 6 × 10–6/K.
Thyroid Dysfunction in Patients with Systemic Connective Tissue Disease
Heba Sayed Assal, Ashraf Elsherbiny, Ahmed Alsayed, Mohamed Abdel Maaboud, Hesham alShabrawi, Enas Abdel Rasheed
Macedonian Journal of Medical Sciences , 2009, DOI: 10.3889/MJMS.1857-5773.2009.0059
Abstract: Background. Alterations in the circulating thyroid hormone concentrations constituting the euthyroid sick syndrome (ESS) are frequently associated with systemic non-thyroidal diseases such as systemic connective tissue disease (SCTD). Aim. to elucidate the pattern of thyroid dysfunction in patients with SCTD. Subjects and Methods. Thirty patients with systemic lupus erythematosus (SLE) and thirty rheumatoid arthritis (RA) patients in addition to 30 healthy age- and sex- matched controls were recruited from the Internal Medicine Department of Ain- Shams University Hospital. Thyroid stimulating hormone (TSH), thyroid hormones including T3 and T4, antithyroglobulin antibodies (ATGAb), thyroid peroxidase antibodies (TPOAb), ESR, RF, ANA, LE cells and CRP were determined. Results. 46.6 percent of SLE patients showed thyroid dysfunction compared to 16.6% of RA (P<0.05). In SLE group, 20% had euthyroid sick syndrome, 16% had hypothyroidism (10% subclinical and 6% overt), and 9% had hyperthyroidism (3% subclinical and 6% overt). However in RA, 13% had hypothyroidism (10% subclinical and 3% overt) and 3% had subclinical hyperthyroidism. TPOAb was found in 16% of SLE and 6% in RA patients. Also ATGAb was found in 6% of SLE and 30% in RA patients and 10% of controls, but the titers were higher in the patients. Conclusion. Thyroid dysfunction was common in patients with SCTD and they were associated with antithyroid antibodies.
Zoonotic Chicken Toxoplasmosis in Some Egyptians Governorates
Ashraf Mohamed Barakat,Lobna Mohamed Ali Salem,Adel M. Abdel-Aziz El-Newishy,Raafat Mohamed Shaapan
Pakistan Journal of Biological Sciences , 2012,
Abstract: Toxoplasmosis is one of the most common diseases prevalent in the world, caused by a coccidian parasite Toxoplasma gondii which infects humans, animals and birds. Poultry consider reliable human source of food in addition it is considered an intermediate host in transmission of the disease to humans. Trails of isolation of local T. gondii chicken strain through bioassay of the suspected infected chicken tissues in mice was carried out and the isolated strain was confirmed as being T. gondii using Polymerase Chain Reaction (PCR). Seroprevalence of antibodies against T. gondii in chicken sera in six Egyptian governorates were conducted by enzyme linked immune-sorbent assay (ELISA) using the isolated chicken strain antigen. Moreover, comparison between the prevalence rates in different regions of the Egyptian governorates were been estimated. Isolation of local T. gondii chicken strain was accomplished from chicken tissues and confirmed by PCR technique. The total prevalence rate was 68.8% comprised of 59.5, 82.3, 67.1, 62.2, 75 and 50% in El Sharkia, El Gharbia, Kafr El sheikh, Cairo, Quena and Sohag governorates, respectively. The prevalence rates were higher among Free Range (FR) (69.5%) than commercial farm Chickens (C) (68.5%); while, the prevalence rate was less in Upper Egypt than Lower Egypt governorates and Cairo. This study is the first was used antigen from locally isolated T. gondii chicken strain for the diagnosis of chicken toxoplasmosis. The higher seroprevalence particularly in free range chickens (house-reared) refers to the public health importance of chickens as source of zoonotic toxoplasmosis to human.
Immune Response after Hepatitis B Vaccination among Egyptian Medical Students in Nile Delta  [PDF]
Reem Elmaghlob, Gamal El Didamony, Ashraf Elbahrawy, Abdallah Mahmoud Abdallah, Mahmoud Haddad Hemida, Ahmed Elwassief, Mohamed Salah Ali, Ahmed Al-Ashker, Abdel-Gawad Saied Mohammad, Mohamed Hanafy Morsy, Hafez Abdelhafeez
World Journal of Vaccines (WJV) , 2015, DOI: 10.4236/wjv.2015.53015
Abstract: Background: Early promotion of hepatitis B (HB) vaccination among health care workers is an important component of the HBV infection control. No available data assess immune response of HB vaccination among Egyptian medical students. Objective: we conducted this study to evaluate the immune response among medical students after completion of their vaccination schedule. Methods: A total of 150 Egyptian medical students were included. Three doses of recombinant HB vaccine had been administered to all participating students at 0, 1 and 6 months. Antibody to hepatitis B surface antigen (Anti-HBs) titers, hepatitis B surface antigen (HBsAg), and total antibody to hepatitis B core antigen (anti-HBc) were measured by enzyme immunoassay, 1 to 2 months after completion of vaccination course. Results: Among 150 students included, the mean age was 22.4 ± 1.7 years (range 18 - 28 years). Fifty nine (39.4%) were males and 91 (60.6%) were females. All students have anti-HBs levels more than 100 IU/L. The mean anti-HBs of included students was 8994.2 ± 6373.1 IU/L. There was no significant difference of anti-HBs levels regarding age, sex, residence or body mass index distribution. Conclusion: Early HB vaccination of health care workers is associated with good immune response and should be encouraged.
Synthesis, Molecular Modeling, and Biological Evaluation of Novel Tetrahydro-β-Carboline Hydantoin and Tetrahydro-β-Carboline Thiohydantoin Derivatives as Phosphodiesterase 5 Inhibitors
Ashraf H. Abadi,Jochen Lehmann,Gary A. Piazza,Mohammad Abdel-Halim,Mohamed S. M. Ali
International Journal of Medicinal Chemistry , 2011, DOI: 10.1155/2011/562421
Abstract: Two series of fused tetrahydro-β-carboline hydantoin and tetrahydro-β-carboline thiohydantoin derivatives with a pendant 2,4-dimethoxyphenyl at position 5 were synthesized, and chiral carbons at positions 5 and 11a swing from R,R to R,S, S,R, and S,S. The prepared analogues were evaluated for their capacity to inhibit phosphodiesterase 5 (PDE5) isozyme. The R absolute configuration of C-5 in the β-carboline hydantoin derivatives was found to be essential for the PDE5 inhibition. Chiral carbon derived from amino acid even if of the S configuration (L-tryptophan) may lead to equiactive or more active isomers than those derived from amino acid with the R configuration (D-tryptophan). This expands the horizon from which efficient PDE5 inhibitors can be derived and may offer an economic advantage. The thiohydantoin derivatives were less active than their hydantoin congeners. 1. Introduction Cyclic nucleotide phosphodiesterases (PDEs) are a superfamily of enzymes responsible for the hydrolysis of cyclic adenosine 3′,5′-monophosphate (cAMP) and cyclic guanosine 3′,5′-monophosphate (cGMP) that are important intracellular second messengers playing a central role in regulating many relevant cell functions. These second messengers are converted to the biologically inactive monophosphates with subsequent termination of their physiological functions. Currently, the PDE system includes 11 families (PDE1-PDE11) comprising 21 different gene products [1–3]. The cGMP-specific phosphodiesterase 5 (PDE5) is abundant in the penile tissue, platelets, vascular, and smooth muscle tissues. This enzyme is the primary target for the development of small molecules, such as the well-known sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) to treat erectile dysfunction [4]. Nitric oxide activates guanylatecyclase to convert GTP to the second messenger cGMP which, in turn, results in smooth muscle relaxation and the erectile response. cGMP is hydrolysed by PDE5 to inactive GMP. PDE5 inhibitors such as sildenafil thus act to inhibit cGMP breakdown and thereby facilitate penile erection in patients suffering from MED [5]. Recently, sildenafil was approved for the treatment of pulmonary hypertension (Revatio), and there are numerous emerging reports relating the elevation of cGMP to anticancer apoptotic actions. This further illustrates the potential of PDE5 inhibitors as therapeutic agents. Chemically speaking, the long-acting PDE5 inhibitor tadalafil is considered as a fused tetrahydro-β-carboline piperazinedione derivative with pendant 1,3-benzodioxol moiety at
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