198 research outputs found
Correction: Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa
No full textThe authors of the article ‘Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa’ [1] wish to acknowledge the contribution of Professor Hussein El Fishawy. Our guidelines drew on various sources, including the Egyptian Ministry of Health guidelines, portions of which were adapted and reproduced with permission from the Egyptian Ministry of Health. Two of the authors of those guidelines, Professors Elsayed and Zaki, are also coauthors of our paper. Professor El Fishawy was the third author of the Egyptian guidelines and we would like to acknowledge his contribution to our review through this source, especially with respect to the treatment algorithms for patients with kidney transplants and those with acute kidney injury. Reference1. Elsayed HM, Wadee S, Zaki MS, Were AJO, Ashuntantang GE, Bamgboye EL, et al. Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa. Afr J Nephrol. 2020; 23(1):109-126
Correction to: Naturally occurring radioactive materials (NORM) concentration and health risk assessment of aerosols dust in Nicosia, North Cyprus (Journal of Radioanalytical and Nuclear Chemistry, (2024), 333, 3, (1073-1082), 10.1007/s10967-023-09346-w)
No full textThe article “Naturally occurring radioactive materials (NORM) concentration and health risk assessment of aerosols dust in Nicosia, North Cyprus”, written by Hesham M. H. Zakaly, Akbar Abbasi, Nouf Almousa and Ahmet Savaşan, was originally published Online First without Open Access. After publication in volume 333, issue 3, page 1073–1082, the author decided to opt for Open Choice and to make the article an Open Access publication. Therefore, the copyright of the article has been changed t
RETRACTED ARTICLE: Effects of dexamethasone on foetal Doppler flow velocimetry
No full textWe, the Editor and Publisher of Journal of Obstetrics and Gynaecology, have retracted the following article: Ahmed M. Nofal, Tarek M. Sayyed, Hesham S. Mahmoud & Tamer Y. Atia (2021). Effects of dexamethasone on foetal Doppler flow velocimetry. Journal of Obstetrics and Gynaecology, 41 (3), 390–394. DOI: 10.1080/01443615.2020.1742677. Since publication, significant concerns have been raised about the statistical analysis in the article. When approached for an explanation, the authors fully cooperated and provided their data, but they have not sufficiently addressed the concerns raised, and concerns remain about the statistical methods in the article. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. The corresponding author listed in this publication has been informed. The authors do not agree with the retraction. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’
Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers
No full textTitle: Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers, Author: Hesham Enshasy, Location: MillsBroadly tunable InGaAsP/InP asymmetric multiple quantum well (AMQW) ridge waveguide laser diodes suffer from low output power. The output power problem of the AMQW laser diodes limits the use of these lasers in certain applications. Both theoretical and experimental studies were carried out in this work to understand the reasons behind this output power problem and to put forth solutions to this problem. As a starting point a commercial beam propagation method (BPM) optical simulator was used to optimize the confinement factor of the laser diodes. The laser diode output power almost doubled as a result of optical confinement optimization, which opens the door for improvement from electrical and thermal optimization. A commercially available partial differential equation solver, FlexPDE, was used to solve the main electronic and thermal equations and simulate a laser diode device. The FlexPDE simulations -which were validated with published data-showed poor current injection efficiency to the center of the device active region. The FlexPDE simulations showed that the main reason for this poor current injection efficiency is the ridge structure. Since the ridge structure is an essential part of this type of laser diode, effort was put forth to reduce the effect of the ridge structure on the current injection efficiency. Both simulation and experimental data showed that extending the doping profile closer to the active area would improve significantly the output power. On the other hand, a proposed forced electrical confinement method showed potential to improve the output power of the device theoretically and experimentally. The over all output power improvement went from a range of 2-5 m W to a range of 15-18 m W as a result of this study. A discussion of the two distinct output power profiles is included in the study, while detailed explanations of the dip in the power profile supported by experimental data are reported. A new method of distance measurement using one of the first, optimized, broadly tunable InGaAsP/InP short-external-cavity diode lasers is reported. Non-linear, least squares fitting method was used to extract estimates of distance from the raw data. This fitting method together with the wide tuning range (100 nm) made it possible to achieve sub-micron resolution of distance even in the presence of noise.ThesisDoctor of Philosophy (PhD
Sex-Based Differences in Systemic Sclerosis Among Egyptian Patients: Insights from a Multicenter Observational Study in a Genetically Distinct North African Mediterranean Population
No full text: Background: Systemic Sclerosis (SSc) is a heterogeneous autoimmune disease with variable clinical expression influenced by genetic, environmental, and sex-related factors. Understanding sex-based differences in disease phenotypes and severity can improve personalized management strategies, especially in underrepresented populations. This study aims to explore sex-based differences in disease phenotypes and severity in a population with a distinct genetic background. Materials and Methods: This cross-sectional study included 197 SSc patients (177 females and 20 males) enrolled from 5 tertiary care centres across Egypt. All participants met the 2013 ACR/EULAR classification criteria for SSc and the criteria proposed by LeRoy and Medsger. The demographic, clinical, and serological data were collected and defined according to the previously developed severity score and activity index. Results: This study highlights key sex-related differences in disease severity and management. Egyptian male patients exhibited more severe skin involvement and were more likely to receive more aggressive treatment regimens, including corticosteroids and phosphodiesterase inhibitors. Conversely, female patients demonstrated a higher frequency of moderate general systemic involvement and comparatively lower rates of pulmonary complications. Conclusions: Sex-related differences in Egyptian SSc patients appear limited, suggesting that population-specific genetic and environmental factors may play a more prominent role in disease expression than sex alone
Author Correction: Structure, Mössbauer, electrical, and γ-ray attenuation-properties of magnesium zinc ferrite synthesized co-precipitation method
No full textIn the original version of this Article M. A. M. Uosif was incorrectly affiliated with ‘Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt’. The correct affiliation is listed below. Physics Department, College of Science, Jouf University, P. O. 2014, Sakaka, Al‑Jouf, Saudi Arabia. The original Article has been corrected. © 2022, The Author(s)
Laser and radiofrequency-induced hyperthermia treatment via gold-coated magnetic nanocomposites
No full textAlsayed AM Elsherbini1, Mahmoud Saber2, Mohamed Aggag2, Ahmed El-Shahawy2, Hesham AA Shokier11National Institute of Laser Enhanced Science, 2Children's Cancer Hospital, Cairo, EgyptIntroduction: The current radiofrequency ablation technique requires invasive needle placement. On the other hand, most of the common photothermal therapeutic methods are limited by lack of accuracy of targeting. Gold and magnetic nanoparticles offer the potential to heat tumor tissue selectively at the cellular level by noninvasive interaction with laser and radiofrequency.Methods: Gold nanospheres and gold-coated magnetic nanocomposites were used for inducing hyperthermia to treat subcutaneous Ehrlich carcinoma implanted in female mice.Results: In mice treated with gold nanospheres, tumors continued to grow but at a slow rate. In contrast, more than 50% of the tumors treated with gold-coated magnetic nanocomposites completely disappeared.Conclusion: This simple and noninvasive method shows great promise as a technique for selective magnetic photothermal treatment.Keywords: laser, hyperthermia, gold magnetic nanocomposites, Ehrlich carcinom
Mushrooms: a potential natural source of anti-inflammatory compounds for medical applications
No full textFor centuries, macrofungi have been used as food and medicine in different parts of the world. This is mainly attributed to their nutritional value as a potential source of carbohydrates, proteins, amino acids, and minerals. In addition, they also include many bioactive metabolites which make mushrooms and truffles common components in folk medicine, especially in Africa, the Middle East, China, and Japan. The reported medicinal effects of mushrooms include anti-inflammatory effects, with anti-inflammatory compounds of mushrooms comprising a highly diversified group in terms of their chemical structure. They include polysaccharides, terpenoids, phenolic compounds, and many other low molecular weight molecules. The aims of this review are to report the different types of bioactive metabolites and their relevant producers, as well as the different mechanisms of action of mushroom compounds as potent anti-inflammatory agent
Fuzzy multi-criteria decision making model for different scenarios of electrical power generation in Egypt
No full textAbstractIn the analytic network process (ANP) a hierarchy or network is created to represent a decision and establishes a matrix containing the pair wise comparison judgments for the elements linked under a parent element. A priority vector of relative weights for these elements is derived. Then all the priority vectors are appropriately weighted and summed to obtain the overall priorities for the alternatives of a decision. In this paper we will develop an efficient fuzzy ANP model which helps decision makers to choose among the alternatives for the Egyptian scenarios of electrical power generation
End-to-End Steering for Autonomous Vehicles via Conditional Imitation Co-Learning
No full textAutonomous driving involves complex tasks such as data fusion, object and lane detection, behavior prediction, and path planning. As opposed to the modular approach which dedicates individual subsystems to tackle each of those tasks, the end-to-end approach treats the problem as a single learnable task using deep neural networks, reducing system complexity and minimizing dependency on heuristics. Conditional imitation learning (CIL) trains the end-to-end model to mimic a human expert considering the navigational commands guiding the vehicle to reach its destination, CIL adopts specialist network branches dedicated to learn the driving task for each navigational command. Nevertheless, the CIL model lacked generalization when deployed to unseen environments. This work introduces the conditional imitation co-learning (CIC) approach to address this issue by enabling the model to learn the relationships between CIL specialist branches via a co-learning matrix generated by gated hyperbolic tangent units (GTUs). Additionally, we propose posing the steering regression problem as classification, we use a classification-regression hybrid loss to bridge the gap between regression and classification, we also propose using co-existence probability to consider the spatial tendency between the steering classes. Our model is demonstrated to improve autonomous driving success rate in unseen environment by 62% on average compared to the CIL method.NCTA 2024 Best Paper Honorable Mentio
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