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49 results on '"Abdel Hafez, Mohammed"'

2. Risk factors for secondary post tonsillectomy hemorrhage

Author

Essam Ali Abo El-magd, Abdel Rahman Ahmed El-Tahan, Sara Abdel Hafez Mohammed, and Mahmoud Elsaid Khalifa

Subjects
General Nursing, Education
Abstract

Introduction: Tonsillectomy is one of the most common worldwide surgical procedures performed by Otolaryngologists which is usually uncomplicated. The most common complication seen after tonsillectomy is hemorrhage. This can be primary or secondary. Primary hemorrhage occurs within twenty four hours after surgery and secondary hemorrhage occurs any time following the initial 24 hours. Although the exact mechanism behind post-tonsillectomy hemorrhage remains unclear. Risk factors can be helpful in pointing toward an etiology. Methods: We performed a retrospective review of 200 patients (above 3 years and of both gender), who were subjected for tonsillectomy with or without adenoidectomy at the ENT Department, Aswan University hospital, and then 50 of them presented with secondary post tonsillectomy hemorrhage (> 24 hours) post-operative, after hospital discharge, between February 2020 and February 2021. Results: Considering risk factors, the patient ages ranged from 4-40 years with a mean of 15.42 years. Most of patients 37 (74%) were male. O positive blood group were predominant in 26 (52%) of patients. Repeated tonsillitis was the most common indication 35 (70%) of patients. bipolar technique was done in most of patients 36 (72%). The majority of patients 31 (62%) were subjected for tonsillectomy without adenoidectomy.

Published
2022

46. Performance analysis of digital cellular radio systems in Nakagami fading and correlated shadowing environment

Author

Abdel-Hafez, Mohammed and Safak, Mehmer

Subjects
Cellular telephones -- Research, Digital communications -- Equipment and supplies, Electromagnetic interference -- Research, Mobile communication systems -- Research, Business, Electronics, Electronics and electrical industries, Transportation industry
Abstract

The bit error rate (BER) performance of digital cellular radio systems was investigated in a Nakagami fading, correlated lognormal shadowing and additive white Gaussian noise (AWGN) environment for noncoherent differential phase shift keying (DPSK) modulation. Two models were used to determine the BER; the first one is based on the cumulative power levels of cochannel interferers while the second one is based on instantaneous cochannel interference power. The relative advantages of the two models were presented for various design parameters. The effects of bit energy to noise ratio, frequency reuse distance, cluster size, correlation coefficient, shadow spread, and fading parameter were studied. The BER was observed to be lower in a correlated shadowing environment compared with the uncorrelated case. The near-far effect was studied by assuming that both the desired and interfering mobiles are randomly located in their corresponding cells. Index Terms - Cellular radio system, cochannel interference, correlated shadowing, multipath fading.

Published
1999

49. Role of oxidative stress and outcome of various surgical approaches among patients with bullous lung disease candidate for surgical interference.

Author

Farouk A, Hassan MH, Nady MA, and Abdel Hafez MF

Abstract

Background: Bullous lung disease is characterized by formation of blebs, bullae and emphysema. We investigate the role of oxidative stress in the pathogenesis of bullous lung disease and compare between conventional thoracotomy versus video assisted thoracoscopic approach in surgical management of such patients., Methods: This study was a prospective case control study and it was carried out on 21 patients (16 males and 5 females) with bullous lung disease selected as candidate for surgical interference. This was in addition to 21 apparently healthy age and sex matched subjects selected as control group. Plasma levels of α1-antitrypsin were estimated using commercially available ELISA assay kit, while plasma levels of malondialdehyde (MDA), β-carotene, vitamin A, vitamin C and vitamin E were estimated using spectrophotometric methods. Conventional thoracotomy approach was done in thirteen patients, while, videothoracoscopic approach was done in eight patients., Results: There were significant higher plasma levels of MDA (P<0.001) and lower plasma levels of β-carotene (P<0.01), vitamin A, vitamin C and vitamin E (P<0.001 for each) among patients with bullous lung disease when compared with the control group. There was non-significant difference regarding the air leakage and the hospital stay among patients with bullous lung disease who managed via conventional thoracotomy approach when compared with those managed via videothoracoscopic approach., Conclusions: This study proves that the oxidative stress plays an important role in the pathogenesis of bullous lung disease. Also there are no significant outcome differences between conventional thoracotomy versus video assisted thoracoscopic approach in surgical treatment of such patients., Competing Interests: The authors have no conflicts of interest to declare.

Published
2016
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