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Search Results: 1 - 10 of 13225 matches for " Ehab El Refaee "
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Decompressive Craniotomy and Fast-Track Duraplasty in Acute Subdural Hematomas  [PDF]
Ehab El Refaee, Ahmed Elsayed, Ahmed El-Fiki, Hisham El Shitany
Open Journal of Modern Neurosurgery (OJMN) , 2019, DOI: 10.4236/ojmn.2019.91005
Abstract: Background: Traumatic subdural hematoma is one of the severe injuries to brain with high mortality rates. Dural opening is often associated with brain herniation against the dural edges due to associated edema that would lead to venous infarction. Aim: The objective of this study is to describe a technical note that would allow fast and effective closure of the dura after hematoma evacuation via duraplasty with analysis of the safety and competency of the technique. Subjects and Methods: The fast-track technique was implemented in 15 successive cases with acute subdural hematoma where the fascia lata flap was prepared and sutured to the planned dural incision before opening the dura, which allowed fast and effective closure of the dura before brain herniation. Subdural bridges were planned by using Gelfoam to prevent venous compression. Analysis of the technique effectiveness was performed by the operative detection of brain herniation, as well as clinical and radiological follow-up of patients. Results: All patients had a Glasgow coma score (GCS) below six before the operation. Mean time from trauma to surgery was five hours. The dura could be effectively closed with no brain herniation in all cases. Nine patients survived (60%), where five of them ended up in a vegetative state. Of these two recovered and three continued in a persistent vegetative state. The mortality rate was 40%. Post-operative infarction was detected in post-operative imaging of four patients. Conclusion: The fast-track duraplasty technique is fast and effective in prevention of brain herniation during surgery with favorable clinical outcome in comparison with the poor and severely deteriorated preoperative clinical presentation. More studies to evaluate the impact of the technique on the survival rate are warranted.
Conservative Plan for Post Traumatic Extradural Hematoma: Risk Factors Favouring Conversion to Surgery  [PDF]
Ahmed El-Fiki, Ehab Abdel Halem
Open Journal of Modern Neurosurgery (OJMN) , 2018, DOI: 10.4236/ojmn.2018.83027
Abstract: Introduction: Extradural hematoma (EDH) is considered one of the most serious and recognized secondary insults of traumatic brain injury (TBI). We will analyse the data of cases required conversion from a conservative to a surgical management and identify the possible patient and disease related risk factors in such cases. Patients and Methods: This prospective study included 90 patients with traumatic EDH, admitted to the Neurotrauma department in Cairo University hospitals from March 2014 to August 2016. Their CT scans reveal EDH alone or with associated cerebral lesions initially fitting the criteria of conservative management. Results: The commonest site is frontal in 21 patients (23.3%), followed by parietotemporal in 18 patients (20%). While Posterior fossa hematomas occurred in 3 cases, which was the least common site (3.3%). The mean size of the EDH was 17.02 ml, with a standard deviation of 6.29 ml. The minimum size was 2 ml and a maximum of 28 ml. The cut off value of the size of the hematoma requiring conversion to a surgical management was 19 ml. Conclusion: Clear indications of EDH evacuation have been well known, however studying which risk factors are more liable to convert conservative management plan to evacuation is important. Increased caution and closer monitoring are required when the size of the hematoma is >19 ml or the hematoma is overlying a venous sinus. Unlike coagulopathy which was found to be a potential risk factor, but larger number study is needed.
Experimental Investigation of Progressive Collapse of Steel Frames  [PDF]
Kamel Sayed Kandil, Ehab Abd El Fattah Ellobody, Hanady Eldehemy
World Journal of Engineering and Technology (WJET) , 2013, DOI: 10.4236/wjet.2013.13006
Abstract: This paper reports two new tests conducted to augment available data highlighting the structural performance of multistory steel frames under progressive collapse. The investigated steel frames had different geometries, different boundary conditions, different collapse mechanisms, different damping ratios and different connections. Overall, the paper addresses how multistory frames would behave when subjected to local damage or loss of a main structural carrying element. The obtained results can form a data base for nonlinear finite element models. The deformations of the investigated steel frames and failure modes under progressive collapse were predicted from the finite element analysis, with detailed discussions presented.
Progressive Collapse of Steel Frames  [PDF]
Kamel Sayed Kandil, Ehab Abd El Fattah Ellobody, Hanady Eldehemy
World Journal of Engineering and Technology (WJET) , 2013, DOI: 10.4236/wjet.2013.13007
Abstract:

This paper investigates the behavior of steel frames under progressive collapse using the finite element method. Non-linear finite element models have been developed and verified against existing data reported in the literature as well as against tests conducted by the authors. The nonlinear material properties of steel and nonlinear geometry were considered in the finite element models. The validated models were used to perform extensive parametric studies investigating different parameters affecting the behavior of steel frames under progressive collapse. The investigated parameters are comprised of different geometries, different number of stories and different dynamic conditions. The force redistribution and failure modes were evaluated from the finite element analyses, with detailed discussions presented.

The Use of Hinged Craniotomy in Comparison to Cisternostomy for Avoiding Bone Flap Replacement Second Surgery in Cases of Decompressive Craniotomy in Traumatic Brain Injury  [PDF]
Ahmed El-Fiki, Ehab Abd-Haleem
Open Journal of Modern Neurosurgery (OJMN) , 2019, DOI: 10.4236/ojmn.2019.91002
Abstract: Introduction: Acute post traumatic subdural hematoma is a clinical condition with increased morbidity and mortality despite the developments in neurosurgery and urgent intervention is required to have best clinical outcome. We will evaluate hinged craniotomy technique in terms of offering adequate brain decompression plus avoiding removal of bone flap which requires second replacement surgery in comparison to cisternostomy effect. Material and Methods: A prospective study was conducted over 30 patients with traumatic acute subdural hematoma presented to neurotrauma unit in Cairo University hospitals from January 2017 to February 2018, operated by hinged craniotomy plus evacuation of hematoma and duroplasty. We avoid rapping the head with elastic bandage post-operative. Generous subcutaneous dissection (5 - 7 cm) all around skin flap was done routinely. Effect of brain decompression was evaluated by measuring the level of brain in relation to skull in post-operative computerized topography. Results: Twenty-one patients operated with initial GCS less than eight. Ten cases (33%) show that cortical surface in relation to skull bone was at inner table, nine cases (30%) at diploid layer and two cases (6.7%) at outer table in post-operative CT brain. Twenty patients died (66.7%); eight patients (26.6%) became fully conscious and two patients (6.7%) had vegetative outcome. No re-operation was done in any of our patients. Conclusion: Hinged craniotomy may be a safe and effective alternative technique with comparable results to cisternotomy in cases of traumatic brain injury that require decompression to avoid second surgery, especially in centres lacking cisternostomy experience. Although gaining cisternostomy experience may help in other indications, future prospective studies with larger number are required.
Synthesis of novel quinazolinone and fused quinazolinones
Mahmoud Refaee Mahmoud,Manal Mohamed El-Shahawi,Fatma Saber Mohamed Abu El-Azm
European Journal of Chemistry , 2011, DOI: 10.5155/eurjchem.2.3.404-409.267
Abstract: A number of novel quinazolinone derivatives have been synthesized using the readily obtainable 2-[(1Z,3E)-1-benzamido-4-phenyl-1,3-butadien-1-yl]-3,1-benzoxazin-4(H)one (1) via the reaction with different nitrogen nucleophiles such as azines, Schiff’s base, primary aromatic amines, diamines, hydrazine hydrate and hydroxylamine.
Analysis and Mitigation of the Narrowband Interference Impact on IR-UWB Communication Systems
Ehab M. Shaheen,Mohamed El-Tanany
Journal of Electrical and Computer Engineering , 2012, DOI: 10.1155/2012/348982
Abstract: The impact of narrowband interference signals on impulse radio ultrawideband (UWB) communication systems has been investigated. A closed form expression for the bit error rate performance of UWB communication system in a Log-normal flat fading channel under such impact is evaluated. The actual UWB channel model is known as a multipath fading channel; however flat fading channel model can be considered with some of the UWB wireless applications such as UWB wireless sensor networks which are characterized by size and energy constraints. Thus, a simple and low-cost one-finger Rake receiver can be used with such wireless systems. It was proven that UWB systems unavoidably suffer from the interference caused by the coexisting systems due to the restraint on their transmission power levels. To this end, we propose an interference canceller scheme which is capable of suppressing the impact of such interference and enhancing the performance of UWB communication systems. The interference canceller scheme performance is also investigated in various scenarios of operation such as the presence of multiple narrowband interference signals, symbol timing error, and a comparison with a notch filter-based case.
Partial eigenvalue assignment problem of linear control systems using orthogonality relations
Mohamed A. Ramadan,Ehab A. El - Sayed
Acta Montanistica Slovaca , 2006,
Abstract: The partial eigenvalue assignment is the problem of reassigning a part of the open-loop spectrum of a linear system by a feedback control, leaving the rest of the spectrum invariant. In the paper, we propose a novel solution to the partial eigenvalue assignment problem of linear control system using orthogonality relations between eigenvectors of the state matrix . Our solution can be implemented with only a partial knowledge of the spectrum and the corresponding eigenvectors of the linear system. We show that, the number of eigenvalues and eigenvectors that need to remain unchanged will not be affected by the feedback. We prove this, the feedback vector must be of real form. A numerical example is given to illustrate the proposed method.
Population Pharmacokinetics of Methotrexate in Egyptian Children with Lymphoblastic Leukemia  [PDF]
Ehab Said EL Desoky, Mohamed H. Ghazal, Rajendra P. Singh, Omnia N. Abdelhamid, Hartmut Derendorf
Pharmacology & Pharmacy (PP) , 2013, DOI: 10.4236/pp.2013.42020
Abstract: Background: Individualization of high dose regimen of methotrexate (MTX) in pediatric patients with acute lymphoblastic leukemia based on pharmacokinetic (PK) parameters can help in optimization of the dose and better control of the disease. Building up of a pharmacokinetic model can help dose optimization. Objectives: A NONMEM based population (POP) PK model has been subsequently developed to evaluate the effect of demographics as covariates to address variability in pharmacokinetics of MTX. Method: Forty one patients (24 males & 17 females) with ranges of age, body weight and height of 3 - 15 years, 13 - 54 kg and 100 - 177 cm respectively and diagnosed as acute lymphoblastic leukemia (ALL) were involved in the study. MTX was administered as i.v. infusion at a dose of 2 gm/m2 over a period of two hour and its plasma concentrations were determined primarily at 24 hr post-dose to be utilized in the building-up of PK model.The initial/prior estimates of volumes of central (V1) and peripheral compartments (V2) and clearance (CL) and inter-compartmental clearance (Q2) for MTX were extracted from literature. The inter-subject variability was estimated for V1 &
Amphetamine Versus Non Amphetamine-Related First Episode Psychosis in Saudi Arabian Patients  [PDF]
Ehab Said EL Desoky, Ashraf M A El-Tantawy, Yasser M. Raya, Abdulhameed Al-Yahya
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.23013
Abstract: Background: Amphetamines are illicit psychostimulant drugs that can induce psychotic symptoms. Very few studies have been conducted in Kingdom of Saudi Arabia (SA) on amphetamine abuse and related psychosis. Recently, the pattern of amphetamine abuse in SA showed a significant trend of increased frequency. Objectives: To investigate the extent of amphetamine abuse in a sample of Saudi patients hospitalized for first episode of acute psychosis. Also, to compare in that sample between amphetamine psychosis and other psychoses regarding demographic data, premorbid personality and symptoms profile. Method: 106 patients with acute psychosis were hospitalized and screening of urine for amphetamine was conducted for all. Patients’ psychiatric evaluation included interviewing, and ICD-10 criteria for personality disorders. 30 healthy subjects were also included for comparison with patients. Results: 34/106 of psychotic patients (32%) were positive for amphetamine in urine (≥ 1000 ng/ml). The frequency of personality disorders was significantly higher (P < 0.01) in the patients (54/106; 51%) compared with healthy subjects (6/30; 20%). Also, the incidence of personality disorders was significantly higher (P < 0.01) in amphetamine positive psychosis (25/34; 73.5%) compared with amphetamine negative psychosis (29/72; 40%). Cluster B personality disorders particularly the antisocial and borderline were significantly higher in amphetamine positive psychosis (13/34; 38%) compared with amphetamine negative psychoses (6/72; 8%). The symptom profile showed significant difference between amphetamine positive and amphetamine negative psychosis as regards ideas of reference (50% vs. 14%), suspiciousness (44% vs. 11%), suicidal ideation (38% vs. 23%), paranoid delusions (29% vs. 17%) and increased pulse or blood pressure (29% vs. 7%) respectively. Conclusion: Screening of amphetamine in urine among patients with first episode of acute psychosis can help and support the clinical distinction of amphetamine psychosis from other types of psychosis. This is therapeutically critical since the line of treatment may be different between the two types of psychoses.
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