Experimental verification of the method for producing a three-dimensional cross-pairs metamaterial structure based on a dielectric AlN cube

This paper presents a method of manufacturing 3D metamaterial structures using laser radiation. Our proposed material, aluminum nitride (AlN), by interaction of a high-energy laser beam undergoes a direct metallization process, a result of which a conductive aluminum layer is formed on the ceramic surface at the spot of the laser radiation. Using this unique feature on all six sides of an AlN ceramic cube, the designed cross-pairs were mapped. Unit cells were exposed to an electromagnetic wave, by which the occurrence of the resonant areas of reflectance and transmittance for 7.27 GHz and 9.14 GHz was observed. To demonstrate the property of the negative refractive index a prism made out of manufactured cubes was created. For a wave propagating through a wedge-shaped prism for certain frequency bands, a negative refraction angle was observed

Vascular e-Learning in the MENA Region during the COVID-19 Pandemic

Introduction: With the steady rise in interest in e-learning and the sudden boost provoked by the COVID-19 pandemic, it becomes necessary to explore the e-learning experience within the medical community in the MENA region. Methods: An online survey was conducted during the early phase of the COVID-19 pandemic (June 15 – October 15, 2020). Results: Seventy-eight vascular surgeons and trainees from 16 countries participated. 88% of the participants were male. 55% attended more than 4 activities. More than half of the activities did not lead to any official certification. Topic was the primary determinant for attending an activity. National societies and social media played a major role in disseminating activity-related information. Lack of time, increased workload, differences in time zone, and technical issues were the main obstacles cited. 84.7% of the participants had a positive impression. Conclusion: As the COVID-19 pandemic boosted e-learning activities in vascular surgery, a shift was observed in the learning mode and new leadership skills were called upon. Novel ways of quality control are required

Dataset of the vascular e-Learning during the COVID-19 pandemic (EL-COVID) survey

10.1016/j.dib.2021.107442Data in Brief38107442

Vascular e-Learning During the COVID-19 Pandemic: The EL-COVID Survey

10.1016/j.avsg.2021.08.001Annals of Vascular Surger

Dataset of the vascular e-Learning during the COVID-19 pandemic (EL-COVID) survey

This dataset supports the findings of the vascular e-Learning during the COVID-19 pandemic survey (the EL-COVID survey). The General Data Protection Regulation (GDPR) of the European Union was taken into consideration in all steps of data handling. The survey was approved by the institutional ethics committee of the Primary Investigator and an online English survey consisting of 18 questions was developed ad-hoc. A bilingual English-Mandarin version of the questionnaire was developed according to the instructions of the Chinese Medical Association in order to be used in mainland People's Republic of China. Differences between the two questionnaires were minor and did affect the process of data collection. Both questionnaires were hosted online. The EL-COVID survey was advertised through major social media. All national and regional contributors contacted their respective colleagues through direct messaging on social media or by email. Eight national societies or groups supported the dissemination of the EL-COVID survey. The data provided demographics information of the EL-COVID participants and an insight on the level of difficulty in accessing or citing previously attended online activities and whether participants were keen on citing these activities in their Curricula Vitae. A categorization of additional comments made by the participants are also based on the data. The survey responses were filtered, anonymized and submitted to descriptive analysis of percentage