Compliance with tobacco control policy and visibility of cigarette retailers around educational facilities in Riyadh, Saudi Arabia

Background: In Saudi Arabia, cardiovascular diseases are among the top causes of death and disability, and smoking is one of the leading risk factors, particularly among males. Objective: Our study aims to evaluate the compliance with the anti-smoking law among cigarette retailers and examine the visibility of cigarette retailers around educational facilities in Riyadh city, Saudi Arabia. Methods: We conducted a mapping survey and geospatial analysis of cigarette retailers around educational facilities from February to March 2020 (before the COVID-19 restriction) in Al-Olaya municipality in Riyadh city as a pilot study. We found 249 retailers, of which 152 sold cigarettes. Data analyses in ArcMap 10.6 compared the visibility within 250 and 500 meters from educational facilities. Results: We found many retailers were not compliant with the tobacco control regulation: 57.1% of minimarkets sell cigarettes, 15.8% of cigarette retailers display the products openly, and 12.5% of cigarette retailers sold cigarettes by the stick. Moreover, 71% of the total cigarette retailers were within 500 m from schools, and 62% of all schools had at least one cigarette retailer within 500 m buffer (5-min walking or 2–3-min driving distance). Conclusion: There is non-compliance with the anti-smoking law among cigarette retailers and high visibility of cigarette retailers around educational facilities in Saudi Arabia. Monitoring is needed for the effective implementation of tobacco control policies

Thermally stable solution processed vanadium oxide as a hole extraction layer in organic solar cells

Low-temperature solution-processable vanadium oxide (V2Ox) thin films have been employed as hole extraction layers (HELs) in polymer bulk heterojunction solar cells. V2Ox films were fabricated in air by spin-coating vanadium(V) oxytriisopropoxide (s-V2Ox) at room temperature without the need for further thermal annealing. The deposited vanadium(V) oxytriisopropoxide film undergoes hydrolysis in air, converting to V2Ox with optical and electronic properties comparable to vacuum-deposited V2O5. When s-V2Ox thin films were annealed in air at temperatures of 100 °C and 200 °C, OPV devices showed similar results with good thermal stability and better light transparency. Annealing at 300 °C and 400 °C resulted in a power conversion efficiency (PCE) of 5% with a decrement approximately 15% lower than that of unannealed films; this is due to the relative decrease in the shunt resistance (Rsh) and an increase in the series resistance (Rs) related to changes in the oxidation state of vanadium

Nanosecond pulsed laser texturing of optical diffusers

High-quality optical glass diffusers have applications in aerospace, displays, imaging systems, medical devices, and optical sensors. The development of rapid and accurate fabrication techniques is highly desirable for their production. Here, a micropatterning method for the fast fabrication of optical diffusers by means of nanosecond pulsed laser ablation is demonstrated (λ=1064 nm, power=7.02, 9.36 and 11.7 W and scanning speed=200 and 800 mm s-1). The experiments were carried out by point-to-point texturing of a glass surface in spiral shape. The laser machining parameters, the number of pulses and their power had significant effect on surface features. The optical characteristics of the diffusers were characterized at different scattering angles. The features of the microscale structures influenced average roughness from 0.8 μm to 1.97 μm. The glass diffusers scattered light at angles up to 20° and their transmission efficiency were measured up to ∼97% across the visible spectrum. The produced optical devices diffuse light less but do so with less scattering and energy losses as compared to opal diffusing glass. The presented fabrication method can be applied to any other transparent material to create optical diffusers. It is anticipated that the optical diffusers presented in this work will have applications in the production of LED spotlights and imaging devices

Millimeter Wave Beam Steerable/Reconfigurable Liquid Metal Array Antenna

This paper presents a mm-wave beam steerable/reconfigurable phased array antenna incorporating Eutectic Gallium Indium Alloy (EGaIn) liquid metal switches. The antenna operates at 26.2 GHz and has a scan range of ±58° which yields a ±40° improvement in scan range over a conventional dipole phased array antenna at a side lobe level of or better than 8.8 dB. Moreover the beam scanning approach proposed here supports continuous beam steering over a much wider scan angle range than is possible with conventional techniques

Laser inscription of pseudorandom structures for microphotonic diffuser applications

Optical diffusers provide a solution for a variety of applications requiring a Gaussian intensity distribution including imaging systems, biomedical optics, and aerospace. Advances in laser ablation processes have allowed the rapid production of efficient optical diffusers. Here, we demonstrate a novel technique to fabricate high-quality glass optical diffusers with cost-efficiency using a continuous CO2 laser. Surface relief pseudorandom microstructures were patterned on both sides of the glass substrates. A numerical simulation of the temperature distribution showed that the CO2 laser drills a 137 μm hole in the glass for every 2 ms of processing time. FFT simulation was utilized to design predictable optical diffusers. The pseudorandom microstructures were characterized by optical microscopy, Raman spectroscopy, and angle-resolved spectroscopy to assess their chemical properties, optical scattering, transmittance, and polarization response. Increasing laser exposure and the number of diffusing surfaces enhanced the diffusion and homogenized the incident light. The recorded speckle pattern showed high contrast with sharp bright spot free diffusion in the far field view range (250 mm). A model of glass surface peeling was also developed to prevent its occurrence during the fabrication process. The demonstrated method provides an economical approach in fabricating optical glass diffusers in a controlled and predictable manner. The produced optical diffusers have application in fibre optics, LED systems, and spotlights

Density of Fast Food Outlets around Educational Facilities in Riyadh, Saudi Arabia: Geospatial Analysis

Background: Childhood obesity remains a public health issue globally. The latest estimate from the World Health Organization showed that over 340 million children and adolescents aged 5–19 were overweight or obese in 2016. Objective: Our study aimed to assess the density of fast food outlets around educational facilities in Riyadh, Saudi Arabia. Methods: We employed geospatial and quantitative analyses using data on fast food outlets (from surveys conducted between November 2019 and May 2020) and educational facilities in Riyadh city. Data analyses conducted using ArcMap 10.6 and Stata 15 compared the density within 500 m and 500–1000 m from the facilities. Results: We found a high density of fast food outlets around educational facilities. Nearly 80% of fast food were within twelve-minute walking or five-minute driving distances from schools, and nearly 70% of all educational facilities had at least one fast food outlet within the buffer. We also found the densities were high within both the areas closer and the areas farther away from educational facilities. In addition, the density was significantly higher around private schools compared to government schools, and the density around girls-only schools and both-gender schools was higher than that around boys-only schools. Conclusion: There is a high density of fast food outlets around educational facilities in Saudi Arabia. Effective policies are needed to help reduce potential exposure to fast food among young people in Saudi Arabia and other countries with similar settings

Message in a bubble: the translational potential of extracellular vesicles

Extracellular vesicles (EVs) are small, membrane-enclosed vesicles released by cells into the extracellular milieu. They are found in all body fluids and contain a variety of functional cargo including DNA, RNA, proteins, glycoproteins and lipids, able to provoke phenotypic responses in cells, both locally and at distant sites. They are implicated in a wide array of physiological and pathological processes and hence have attracted considerable attention in recent years as potential therapeutic targets, drug delivery vehicles and biomarkers of disease. In this review we summarise the major functions of EVs in health and disease and discuss their translational potential, highlighting opportunities of – and challenges to – capitalising on our rapidly increasing understanding of EV biology for patient benefit