Mahmoud Ashour - Academia.edu (original) (raw)

Papers by Mahmoud Ashour

The Internet Journal of Anesthesiology, 2003

Goiter is a known risk factor for difficult airway management. We report the anesthetic managemen... more Goiter is a known risk factor for difficult airway management. We report the anesthetic management of a case of huge multinodular goiter with compromised airway. When thyroid enlargement is accompanied by airway deformity, it presents an aggravating factor for difficult direct laryngoscopy and difficult tracheal intubation. Under similar situations where the trachea is compressed and markedly shifted to one side, and whenever possible, airway access under local anesthesia constitutes better alternative to failed fiberoptic intubation.

Annals of Tropical Paediatrics, 1990

A 13-year-old girl presented with fever, night sweat, weight loss, abdominal pain, haematuria and... more A 13-year-old girl presented with fever, night sweat, weight loss, abdominal pain, haematuria and hepatosplenomegaly. Urinalysis revealed many Schistosoma haematobium ova, but rectal snip examination was negative for schistosomal ova. X-ray and CT scan of the chest revealed enlargement of the anterior, superior, mediastinal and left suprahilar lymph node with an adjacent left pulmonary parenchymal opacity and small peripheral lesions on the right side. A bone marrow aspiration and biopsy was normal. The patient was treated with Praziquantel for her urinary schistosomiasis. Because of her clinical and radiological chest findings, the possibilities of lymphoma and tuberculosis were considered. Therefore, she underwent a thoracotomy and biopsy of her thoracic lesions. The histopathology revealed pulmonary granulomas surrounding schistosoma ova with reactive mediastinal lymph adenitis.

2009 4th International Conference on Design & Technology of Integrated Systems in Nanoscal Era, 2009

In positron emission tomography (PET) scanners, the depth of interaction (DOI) is a great interes... more In positron emission tomography (PET) scanners, the depth of interaction (DOI) is a great interest research area. To gain the DOI information, different pulse shape discrimination (PSD) techniques are used for crystal-identification of phoswich detectors. This paper evaluates two recent PSD algorithms due to their discrimination performance of two different pulses types. These pulses recorded from LSO and LuYAP crystals.

2008 Mosharaka International Conference on Communications, Propagation and Electronics, 2008

Page 1. 1 Power Efficient Polyphase Decomposition Comb Decimation Filter in Multi-Rate Telecommun... more Page 1. 1 Power Efficient Polyphase Decomposition Comb Decimation Filter in Multi-Rate Telecommunication Receivers Noha Younis Ahmed Amin Mohamed Nassar Microelectronics Design Center Fig.1: Polyphase decomposition of comb decimation filter, decimating by M. ...

2003 46th Midwest Symposium on Circuits and Systems

I. INTRODUCTION In recent years there has been interest in the implementations of the Viterbi alg... more I. INTRODUCTION In recent years there has been interest in the implementations of the Viterbi algorithm. The Viterbi algorithm is commonly used for the decoding of the convolutional and trellis codes. In addition, the Viterbi algorithm can be used for sequence estimation. In this ...

2010 International Conference on Microelectronics, 2010

Abstract A generalized power efficient clock distribution technique for the input registers of th... more Abstract A generalized power efficient clock distribution technique for the input registers of the polyphase comb decimation filter is presented. A general form of the proposed technique is developed for any integer decimation factor. The Spartan3 low power FPGAs family is ...

2009 International Conference on Advances in Computational Tools for Engineering Applications, 2009

Carrier Frequency Offset (CFO) estimation and correction is a critical issue in all OFDM receiver... more Carrier Frequency Offset (CFO) estimation and correction is a critical issue in all OFDM receivers. For WiMAX Physical layer it is even more challenging to introduce a suitable CFO sub-system since WiMAX system supports complex features for future applications such as multiuser, multi-access and high mobility operation. This paper is concerned with low cost hardware implementation of CFO sub-system on

2007 International Conference on Computer Engineering & Systems, 2007

... modeling WiMAX OFDM transmitter as published in [8]. Modeling end to end physical layer will ... more ... modeling WiMAX OFDM transmitter as published in [8]. Modeling end to end physical layer will be illustrated in the following section in three steps, first WiMAX transmitter model second WiMAXreceiver then end-to-end system with channel estimation and equalization model. ...

2008 International Conference on Computer Engineering & Systems, 2008

OFDM Wireless systems are currently in the focus of research and development. High hardware cost ... more OFDM Wireless systems are currently in the focus of research and development. High hardware cost of such systems is an initiative to redesign the critical functional blocks in order to satisfy timing and power constrains as well as to minimize overall circuit complexity and cost. One such critical functional block is the CoOrdinate Rotation DIgital Computer (CORDIC) that can be

Microelectronics Journal, 2000

... MA Ashour Corresponding Author Contact Information , E-mail The Corresponding Author and HI S... more ... MA Ashour Corresponding Author Contact Information , E-mail The Corresponding Author and HI Saleh. ... Hence, in this paper, a performance evaluation and comparison (efficient area and moderate speed) for different serialparallel multiplier structures have been carried out for ...

IEE Proceedings - Circuits, Devices and Systems, 2001

New designs of serial-parallel multipliers based on the modified Booth and multi-bit recoding alg... more New designs of serial-parallel multipliers based on the modified Booth and multi-bit recoding algorithms are introduced. Using recoding for the parallel operand, two proposed systolic multipliers have been introduced to build structures having ni2 and ni3 cells. The proposed serialparallel multipliers are compared with other structures on the basis of multiplication time, area, and complexity. By using multi-bit overlapped recoding of the multiplier operand, the multiplier operates at twice the speed of the existing dcsigns and has a much lower A T2 complexity.

Clinical Nuclear Medicine, 1994

Medical images are a diagnostic technique that facilitates the doctor's job the doctor to ear... more Medical images are a diagnostic technique that facilitates the doctor's job the doctor to early diagnose the patient. So, fractional edge detection algorithms have gained focus of many researchers with the medical images. The fractional edge detection could be helped in the diagnosis of early stages of diseases like Alzheimer and fracture bone, but it can lose some edge details that can facilitate the doctor's job the doctor in the diagnosis. In this paper, different fractional edge detection algorithms based on fuzzy logic have been used to enhance the performance of the edges as there is no loss in the fuzzy-based methods. A performance comparison has been done between different fractional edge detection algorithms with and without fuzzy logic. Evaluation of the noise performance upon addition of salt and pepper noise is measured through peak signal to noise ratio (PSNR) and bit error rate (BER) simulated by using MATLAB. Key-Words: Edge Detection, Fractional Systems, Soft...

Bulletin de la Société de Géographie d'Egypte, 2015

In the Abu El-Egl playa basin between Kharga and Dakhla, below the Abu Tartur plateau, over 10 m ... more In the Abu El-Egl playa basin between Kharga and Dakhla, below the Abu Tartur plateau, over 10 m thick thinly stratified sediments remain as long dissected ridges. On the basis of luminescence ages they were deposited during the humid period in the Sahara corresponding to MIS 5, up to a level of a lake at about 180 m a.s.l. The floor, at about 170 m a.s.l., consisting of homogenous loamy material and sands with an early Holocene luminescence age, surrounds the ridges. The playa floor was later occupied at about 7000 yr BP according to radiocarbon ages of charcoal from fireplaces and a sample of ostrich eggshell. The main erosion of the old lake sediments was assumed to have taken place during the humid period of MIS 3, before the subsequent arid period of MIS 2. This is supported by the finds of Middle Palaeolithic artefacts on the playa floor between the ridges of the eroded lake sediments.

American Journal of Case Reports, 2018

Objective: Rare disease Background: Leiomyomas are benign neoplasms of the smooth muscle. When fo... more Objective: Rare disease Background: Leiomyomas are benign neoplasms of the smooth muscle. When found in the pulmonary system, a rare occurrence, leiomyomas can result in hypertrophic osteoarthropathy, or significant clubbing, associated with proliferation of long bone periosteum. Bronchopulmonary fistulas, or communications between the bronchial tree and pleural space, are an uncommon postoperative complication of pneumonectomies. Even more infrequent is the presence of a bronchopulmonary fistula that is determined to be sterile. Case Report: The patient presented in the current case report is a 40-year-old previously healthy woman who presented with a 5-year history of chronic cough, right-sided chest discomfort, and dyspnea associated with back pain, and lower leg pain. The CT scan performed on the patient revealed a mass originating from the right lower lobe. Activity at the site of the lesion, in the long bones of the upper and lower limbs, rib cage, and vertebral bones was demonstrated by a bone scan. A CT-guided biopsy was performed, and the pathology report confirmed the presence of a leiomyoma. Following a right-sided lobectomy, the resected tumor was sent for histopathology, with the results confirming the biopsy. The patient subsequently presented with a history of persistent cough associated with increased watery secretions. The CT scan revealed the presence of a bronchopleural fistula, after which the patient underwent surgical correction. All symptoms resolved, and the patient was discharged in stable condition. Conclusions: Here, we report on a patient who presented with 3 rare clinical findings: pulmonary leiomyoma, hypertrophic osteoarthropathy, and sterile bronchopulmonary fistula.

Geosciences, 2020

The article reviews the state of knowledge about distribution, sizes, dynamics, and ages of all s... more The article reviews the state of knowledge about distribution, sizes, dynamics, and ages of all sand seas (N = 6) and dune fields (N = 10) in Egypt (1,001,450 km2). However, chronological data (Optically Stimulated Luminescence, Thermoluminescence), used in the INQUA (International Union for Quaternary Research) dune database, only exists from three of the five sand seas located in the Western Desert of Egypt. The North Sinai Sand Sea and four of the ten dune fields are located near the Nile Valley, the delta or the coast and therefore changed drastically due to land reclamation during the last decades. Here, but also in the oases, their sands pose a risk for settlements and farmland. Our comprehensive investigations of satellite images and our field measurements show that nearly all terrestrial dune forms can be observed in Egypt. Longitudinal dunes and barchans are dominant. Sand seas cover about 23.8% (with an average sand coverage of 74.8%), dune fields about 4.4% (with an avera...

Automatica, 2019

As IP video services have emerged to be the predominant Internet application, how to optimize the... more As IP video services have emerged to be the predominant Internet application, how to optimize the Internet resource allocation, while satisfying the quality of experience (QoE) for users of video services and other Internet applications becomes a challenge. This is because the QoE perceived by a user of video services can be characterized by a staircase function of the data rate, which is nonconcave and hence it is ''hard" to find the optimal operating point. The work in this paper aims at tackling this challenge. It considers the packet routing problem among multiple end points in packet switching networks based on a connectionless, hop-by-hop forwarding paradigm. We model this traffic allocation problem using a fluid flow model and let the link bandwidth be the only resource to be shared. To maximize the utilization of resources and avoid congestion, we formulate the problem as a network utility maximization problem. More precisely, the objective of this paper is to design a Fully Distributed Traffic Allocation Algorithm (FDTAA) that is applicable to a large class of nonconcave utility functions. Moreover, FDTAA runs in a fully distributed way: it enables each router to independently address and route each data unit using immediate local information in parallel, without referring to any global information of the communication network. FDTAA requires minimum computation workload, since the routing decision made at each router is solely based on the destination information carried in each unit. In addition, the network utility values corresponding to the FDTAA iterate sequence converge to the optimal network utility value at the rate of O(1/K), where K is the iteration counter. These theoretical results are exemplified by the simulation performed on an example communication network.

Anaesthesia and Intensive Care, 1994

Annals of Saudi Medicine, 1996

Postintubation tracheal stenosis is a recognized problem. Although its incidence has recently dec... more Postintubation tracheal stenosis is a recognized problem. Although its incidence has recently decreases, it is still a difficult complication to treat. We have reviewed our experience with 10 patients with tracheal stenosis over the last five years between 1990 and 1995. There were seven male and three female patients with an average age of 14.2 +/- 4 years (range 6 to 48 years). Resection and reconstruction with primary anastomosis was performed in seven patients, while conservative treatment with dilatation was performed in two patients. One patient refused surgery. Operations performed included resection of tracheocricoid segment with tracheothyroid anastomosis (N=3) and tracheal resection with end-to-end anastomosis (N=4). The resected airway segment ranged from 3 cm to 6 cm. In view of the intense inflammatory and fibrotic process in and around the stenotic segment, the practice of tracheostomy for the relief of postintubation acute tracheal obstruction should not be taken lightly, as it adds not only to the severity of the inflammatory process, but also increases the length of the tracheal segment to be resected. Postoperatively, all patients were extubated; this was accomplished by the end of surgery in six patients, while the seventh patient was extubated three weeks later. There was no mortality in this series. When normal functional activity and airway patency were taken as two parameters to judge the outcome of surgery, results were good in six (86%) patients and satisfactory in one. These results support the validity of one-stage reconstruction approach as one alternative for the treatment of postintubation tracheal and tracheosubglottic stenotic lesions.

Interactive CardioVascular and Thoracic Surgery, 2015