Internet Use and Addiction Among Medical Students in Qassim University, Saudi Arabia

ABSTRACT: Objectives: This study aimed to measure the prevalence of Internet use and addiction and determine its association with gender, academic performance and health among medical students. Methods: This cross-sectional study was conducted between December 2017 and April 2018 at the College of Medicine, Qassim University, Buraydah, Saudi Arabia. The validated Internet Addiction Test questionnaire was distributed by simple random methods to medical students (N = 216) in the pre-clinical phase (first-, second- and third-years). A chi-square test was used to determine significant relationships between Internet use and addiction and gender, academic performance and health. Results: A total of 209 student completed the questionnaire (response rate: 96.8%) and the majority (57.9%) were male. In total, 12.4% were addicted to the Internet and 57.9 had the potential to become addicted. Females were more frequent Internet users than males (P = 0.006). Academic performance was affected in 63.1% of students and 71.8% lost sleep due to late-night Internet use, which affected their attendance to morning activities. The majority (59.7%) expressed feeling depressed, moody or nervous when they were offline. Conclusion: Internet addiction among medical students at Qassim University was very high, with addiction affecting academic performance and psychological well-being. Suitable interventional and preventive measures are needed for proper Internet use to protect students’ mental and physical health.Keywords: Internet; Addictive Behavior; Medical Students; Universities; Academic Performance; Saudi Arabia

Synthesis of 2D Germanane (GeH):a New, Fast, and Facile Approach

Germanane (GeH), a germanium analogue of graphane, has recently attracted considerable interest because its remarkable combination of properties makes it an extremely suitable candidate to be used as 2D material for field effect devices, photovoltaics, and photocatalysis. Up to now, the synthesis of GeH has been conducted by substituting Ca by H in a beta-CaGe2 layered Zintl phase through topochemical deintercalation in aqueous HCl. This reaction is generally slow and takes place over 6 to 14 days. The new and facile protocol presented here allows to synthesize GeH at room temperature in a significantly shorter time (a few minutes), which renders this method highly attractive for technological applications. The GeH produced with this method is highly pure and has a band gap (E-g) close to 1.4 eV, a lower value than that reported for germanane synthesized using HCl, which is promising for incorporation of GeH in solar cells

Nanosecond pulse generation with a gallium nitride saturable absorber

A mode-locked nanosecond Erbium-doped fiber laser (EDFL) was demonstrated using gallium nitrate (GaN) in the form of a polished crystal as a saturable absorber (SA). The GaN film exhibited a modulation depth of 2% with a saturable optical intensity of 0.46 MW/cm2. The laser directly produced nanosecond pulses with stable mode-locking operation at a pump threshold of 149.51 mW. The generated output pulses operated at a 1562 nm central wavelength with a pulse duration and a repetition rate of 485 ns and 967 kHz, respectively. The average output power was 3.068 mW at a pump power of 182.34 mW, corresponding to 3.1 nJ single pulse energy. These results indicate that GaN material has a promising application in ultrafast light generation. © 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Exploring the interaction between 3-D structure of TLR 9 and prostaglandin analogues

Toll-like receptor 9 (TLR9) is a class of pattern recognition receptors (PRRs) approved to have an essential role with the development of autoimmune illnesses such as psoriasis and arthritis. TRL9 is predominantly expressed on dendritic cells (DCs) and macrophages, and it mediates antigen presentation to T cells. In this regard, interfering with this interaction by inhibiting TLR9 could be an effective immunotherapy strategy for certain diseases. Based on previous research (Degraaf et al.2014, Farrugia et al., 2017) indicating that prostaglandins play a significant role in regulating or reducing the expression of TLRs, their function against intracellular TLRs such as TLR9 may involve direct inhibition of these receptors. The 3D structure of the human-TLR9 is modelled and described molecularly and then prepared to be docked by prostaglandin analogues, followed by molecular dynamic (MD) simulation, MM/PBSA analysis, and PCA analysis. The study uncovered significant direct interactions between TLR9 and prostaglandin analogues, specifically with the FDA-approved Bimatoprost (BI), which demonstrates the highest binding affinity (calculated as an estimated affinity) and an interesting MM/PBSA score and should be the primary focus of future research into the treatment of autoimmune diseases. In addition, the modelled structure of human-TLR9 and its binding site described in this study could serve as a useful starting point for the development of additional inhibitors

Tris-(8-hydroxyquinoline) aluminium thin film as saturable absorber for passively Q-switched erbium-doped fibre laser

A passively Q-switched erbium-doped fibre laser was demonstrated by using tris-(8-hydroxyquinoline)aluminium (Alq3) organic material as a passive saturable absorber (SA). The SA was fabricated by a drop casting technique at room temperature and incorporated into a laser cavity by inserting it between two optical fibre ferrules. The Q-switched fibre laser operates at a centre wavelength of 1559 nm with a full-width half maximum of 1 nm. The generated pulse train is stable and has a pulse width decreased from 6.65 to 1.2 μs and the pulse repetition rate increased from 31.65 to 144.5 kHz as the pump power increased from 20 to 122 mW. The maximum pulse energy obtained is 63.89 nJ. This work indicates that the Alq3 as SA has a great potential to be utilised for pulsed laser generation. To the best of the authors' knowledge, this is the first time an organic material is utilised as a SA device for generating a stable Q-switched laser pulse. © 2019 Institution of Engineering and Technology. All rights reserved