Ahmed Mosad

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Alexander Morrison

University of Oxford

John Xiros Cooper

University of British Columbia

James Elkins

School of the Art Institute of Chicago

Mark Byron

The University of Sydney

Dan Hicks

University of Oxford

Natsumi Ikoma

International Christian University

David Seamon

Kansas State University

Emrah Safa Gürkan (ESG)

Istanbul 29 Mayis University

Stéphane Péquignot

Ecole Pratique des Hautes Etudes

Julia Miele Rodas

City University of New York

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Papers by Ahmed Mosad

Analysis of inductive characteristics for various helical and spiral coil configurations supported by COMSOL Multiphysics. (Dept. E)

MEJ. Mansoura Engineering Journal

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Psychological Impact of COVID-19 on Emergency Medicine Trainee Residents in Saudi Arabia: A Cross-Sectional Quantitative Study

Background: Psychological stress has been high among healthcare workers on the frontlines fightin... more Background: Psychological stress has been high among healthcare workers on the frontlines fighting coronavirus disease 2019 (COVID-19). Emergency medicine (EM) residents are members of the frontline care teams in the fight against COVID-19, which puts them at a higher risk of psychological stress compared to other medical trainees. This study examined the psychological impact of this pandemic on EM trainee residents in Saudi Arabia.Methods: This cross-sectional quantitative study used a survey sent to EM trainee residents throughout Saudi Arabia. The questionnaire collected demographic data and included questions evaluating stress, anxiety, depression, and burnout experienced while working during the pandemic.Results: Of the 100 respondents eligible for inclusion, 85% were aged between 25 and 30, 32% were in the R1 training level, 52% were training in the Central region of Saudi Arabia, 92% were directly managing patients with COVID-19, 19% had been infected with COVID-19, 54% were ...

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Global variation in anastomosis and end colostomy formation following left‐sided colorectal resection

BJS Open, 2019

Background: End colostomy rates following colorectal resection vary across institutions in high-i... more Background: End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods: This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle-and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results: In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6⋅9 per cent) from low-HDI, 254 (15⋅5 per cent) from middle-HDI and 1268 (77⋅6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57⋅5, 40⋅9 and 35⋅4 per cent; P < 0⋅001) and subsequent use of end colostomy (52⋅2, 24⋅8 and 18⋅9 per cent; P < 0⋅001) in low-compared with middle-and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3⋅20, 95 per cent c.i. 1⋅35 to 7⋅57; P = 0⋅008) after risk adjustment for malignant disease (OR 2⋅34, 1⋅65 to 3⋅32; P < 0⋅001), emergency surgery (OR 4⋅08, 2⋅73 to 6⋅10; P < 0⋅001), time to operation at least 48 h (OR 1⋅99, 1⋅28 to 3⋅09; P = 0⋅002) and disease perforation (OR 4⋅00, 2⋅81 to 5⋅69; P < 0⋅001). Conclusion: Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone. * Members of the GlobalSurg Collaborative are collaborators in this study and are listed in Appendix S1 (supporting information)

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Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

British Journal of Surgery, 2019

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practi... more Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89·6 per cent) compared with that in countries with a middle...

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Memristor-based relaxation oscillators using digital gates

Proceedings - ICCES 2012: 2012 International Conference on Computer Engineering and Systems, 2012

ABSTRACT This paper presents two memristor-based relaxation oscillators. The proposed oscillators... more ABSTRACT This paper presents two memristor-based relaxation oscillators. The proposed oscillators are designed without the need of any reactive elements, i.e., capacitor or inductor. As the &quot;resistance storage&quot; property of the memristor can be exploited to generate the oscillation. The proposed oscillators have the advantage that they can be fully integrated on-chip giving an area-efficient solution. Furthermore, these oscillators give higher frequency other than the existing reactance-less oscillator and provide a wider range of the resistance. The concept of operation and the mathematical analysis for the proposed oscillators are explained and verified with circuit simulations showing an excellent agreement.

Evaluation of live-donor kidney transplant survival in low body weight Egyptian children: 25 year-experience

Diálisis y Trasplante, 2012

Background: Identification of problems associated with kidney transplantation in small weight chi... more Background: Identification of problems associated with kidney transplantation in small weight children is an essential step toward improving graft function and patient survival. Methods: This study comprised 63 renal transplant children weighing 25 kg or less at time of renal transplantation. All children have received living-donor renal allotransplant between December 1984 and March 2009. These children were retrospectively evaluated regarding their survival, grafts survival as well as associated risk factors. Results: Our patient and graft survival rates at 1, 5 and 10 years were (98.4%, 96.8%, and 96.8%) and (94.9%, 82.6%, and 58.4%), respectively. Significant better graft survival was obtained in cases with non-glomerular etiology of the end-stage renal disease, pre-emptive transplantation and when the aorta was used for arterial vascular anastomosis. Significant worse graft survival was documented among those who experienced pre-transplant hypertension, pre-transplant blood transfusion, post-transplant acute rejection, chronic rejection, hypertension and graft obstruction. The outcome of live donor renal transplantation in children weighing 15---25 kg in our locality as a developing country is comparable to other reports. Better graft survival rates might be obtained by adopting pre-emptive transplant policy, avoiding pre-transplant blood transfusions, using aorta for arterial vascular anastomosis in addition to adopting recent tacrolimus-based immunosuppressive regimens that is associated with reduced incidence of post-transplant acute rejection and graft dysfunction.

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Improved memristor-based relaxation oscillator

Microelectronics Journal, 2013

This paper presents an improved memristor-based relaxation oscillator which offers higher frequen... more This paper presents an improved memristor-based relaxation oscillator which offers higher frequency and wider tunning range than the existing reactance-less oscillators. It also has the capability of operating on two positive supplies or alternatively a positive and negative supply. Furthermore, it has the advantage that it can be fully integrated on-chip providing an area-efficient solution. On the other hand, The oscillation concept is discussed then a complete mathematical analysis of the proposed oscillator is introduced. Furthermore, the power consumption of the new relaxation circuit is discussed and validated by the PSPICE circuit simulations showing an excellent agreement. MATLAB results are also introduced to demonstrate the resistance range and the corresponding frequency range which can be obtained from the proposed relaxation oscillator.

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Generalized Analysis of Symmetric and Asymmetric Memristive Two-Gate Relaxation Oscillators

IEEE Transactions on Circuits and Systems I: Regular Papers, 2013

Memristive oscillators are a novel topic in nonlinear circuit theory, where the behavior of the r... more Memristive oscillators are a novel topic in nonlinear circuit theory, where the behavior of the reactive elements is emulated by the memristor. This paper presents symmetric and asymmetric memristive two-gate relaxation oscillators. First, the analysis of the two series memristors is introduced to study the effect of changing their polarities, as well as the mobility factor to be used in the two-gate relaxation oscillator instead of the RC circuit. The generalized analysis for the proposed memristive two-gate oscillator is introduced, where the generalized expressions for the oscillation frequency and conditions for oscillation are derived then four special cases for different mismatching of the memristors are introduced; showing a perfect matching with the PSPICE simulations. Finally, the discussion and comparison are proposed to discuss the four special cases and MATLAB simulations are also provided to study the effect of the memristance and the mobility ratio between the memristors on the oscillation frequency.

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Global economic burden of unmet surgical need for appendicitis

British Journal of Surgery

Background There is a substantial gap in provision of adequate surgical care in many low- and mid... more Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality wa...

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Analysis of inductive characteristics for various helical and spiral coil configurations supported by COMSOL Multiphysics. (Dept. E)

MEJ. Mansoura Engineering Journal

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Psychological Impact of COVID-19 on Emergency Medicine Trainee Residents in Saudi Arabia: A Cross-Sectional Quantitative Study

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Global variation in anastomosis and end colostomy formation following left‐sided colorectal resection

BJS Open, 2019

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Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

British Journal of Surgery, 2019

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