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- Alharbi, Essa A., et al.
(författare)
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Formation of High-Performance Multi-Cation Halide Perovskites Photovoltaics by delta-CsPbI3/delta-RbPbI3 Seed-Assisted Heterogeneous Nucleation
- 2021
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Ingår i: Advanced Energy Materials. - : John Wiley & Sons. - 1614-6832 .- 1614-6840. ; 11:16
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Tidskriftsartikel (refereegranskat)abstract
- The performance of perovskite solar cells is highly dependent on the fabrication method; thus, controlling the growth mechanism of perovskite crystals is a promising way towards increasing their efficiency and stability. Herein, a multi-cation halide composition of perovskite solar cells is engineered via the two-step sequential deposition method. Strikingly, it is found that adding mixtures of 1D polymorphs of orthorhombic delta-RbPbI3 and delta-CsPbI3 to the PbI2 precursor solution induces the formation of porous mesostructured hexagonal films. This porosity greatly facilitates the heterogeneous nucleation and the penetration of FA (formamidinium)/MA (methylammonium) cations within the PbI2 film. Thus, the subsequent conversion of PbI2 into the desired multication cubic alpha-structure by exposing it to a solution of formamidinium methylammonium halides is greatly enhanced. During the conversion step, the delta-CsPbI3 also is fully integrated into the 3D mixed cation perovskite lattice, which exhibits high crystallinity and superior optoelectronic properties. The champion device shows a power conversion efficiency (PCE) over 22%. Furthermore, these devices exhibit enhanced operational stability, with the best device retaining more than 90% of its initial value of PCE under 1 Sun illumination with maximum power point tracking for 400 h.
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- Alotaibi, Mohammad, et al.
(författare)
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The effect of a decontamination protocol on contaminated titanium dental implant surfaces with different surface topography in edentulous patients
- 2019
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Ingår i: Acta Odontologica Scandinavica. - : Taylor and Francis Ltd. - 0001-6357 .- 1502-3850. ; 77:1, s. 66-75
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate if it is possible to achieve complete decontamination of dental implant surfaces with different surface characteristics. Materials and methods: Twelve implant pieces with an Osseotite® surface and 12 implant pieces with a Ti-Unite® surface were attached on to the complete lower dentures of six patients and were allowed to accumulate plaque for 30 days. When retrieved, the implant decontamination protocol used, involved both mechanical (PeriBrush™) and chemical (3% H2O2) decontamination. The number of colony forming units per millilitre was determined and the dominant micro-organisms in selected samples was identified by 16s rRNA gene amplicon sequencing. The effect of the titanium brush on the implant surface was examined by SEM. Results: Complete decontamination was achieved in five out of 24 implants (four Osseotite® and one Ti-Unite®). The mean CFU/ml detected after decontamination were 464.48 for Osseotite® and 729.09 for Ti-Unite® implants. On the surface of the implants in which complete decontamination was not achieved, all of the predominant bacteria identified were streptococci except for one which was identified as micrococcus. SEM images revealed that the surface features of the decontaminated implants were not significantly altered. Conclusions: Mechanical decontamination using a titanium brush supplemented with chemical treatment for one minute (3% H2O2) can achieve complete decontamination of implant surfaces in edentulous patients. © 2018, © 2018 Acta Odontologica Scandinavica Society.
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- Mallhi, Tauqeer Hussain, et al.
(författare)
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Estimation of Psychological Impairment and Coping Strategies during COVID-19 Pandemic among University Students in Saudi Arabia : A Large Regional Analysis
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 19:21
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Tidskriftsartikel (refereegranskat)abstract
- Background: The COVID-19 pandemic and associated restrictive measures have substantially affected educational processes around the globe, resulting in psychological distress among students. The mental health of students in higher education is of paramount importance, and the COVID-19 pandemic has brought this vulnerable population into renewed focus. In this context, the evaluation of students' mental health at educational institutes has gained invaluable popularity during the COVID-19 pandemic. This study aimed to ascertain the psychological health and coping strategies among students from a higher education institute in Saudi Arabia.Methods: An online study instrument was used to assess anxiety (Generalized Anxiety Disorder-7, GAD-7), depression (Patient Health Questionnaire-9, PHQ-9), post-traumatic stress disorder-PTSD (Impact of Event Scale-Revised, IES-R) and coping strategies (Brief-COPE). The severity of the psychological distress was classified as per the scoring criteria and correlated with demographics using appropriate statistical methods.Results: Of 1074 students (age 21.1 +/- 2.1 years), 12.9% and 9.7% had severe anxiety and depression, respectively. The mean anxiety and depression scores were 7.50 +/- 5.51 and 9.31 +/- 6.72, respectively. About one-third (32%) of students reported suicidal ideation, with 8.4% students having such thoughts nearly every day. The average PTSD score was 21.64 +/- 17.63, where avoidance scored higher (8.10 +/- 6.94) than intrusion and hyperarousal. There was no association of anxiety, depression and PTSD score with the demographics of the study participants. Religious/spiritual coping (5.43 +/- 2.15) was the most adoptive coping mechanism, followed by acceptance (5.15 +/- 2.10). Male students were significantly (p < 0.05) associated with active copings, instrumental support, planning, humor, acceptance and religious coping. Substance use was the least adopted coping strategy but practiced by a considerable number of students.Conclusions: The long-lasting pandemic situation, onerous protective measures and uncertainties in educational procedures have resulted in a high prevalence of psychological ailments among university students, as indicated in this study. These findings accentuate the urgent need for telepsychiatry and appropriate population-specific mental health services to assess the extent of psychological impairment and to leverage positive coping behaviors among students.
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4. |
- Muzaffar, Nimra, et al.
(författare)
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Designing of VCuS@MXene nanocomposite electrode for energy storage device and electrochemical glucose sensor
- 2024
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Ingår i: Journal of materials science. Materials in electronics. - : Springer Nature. - 0957-4522 .- 1573-482X. ; 35:9
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Tidskriftsartikel (refereegranskat)abstract
- MXene, a two-dimensional (2D) material composed of transition metal carbides (TMCs) and nitrides, have fascinated substantial scientific interest. This increased interest results from their exceptional properties, which include extraordinary conductivity, transparency, outstanding absorbing capacity, and significant charge storage capacities. In this work, the MXene-doped vanadium copper sulfide (VCuS) was synthesized through the hydrothermal method. In three electrode measurement system, the VCuS/MXene composite electrode showed exhibited a specific capacity (Qs) of 1620 Cg−1. As application point of view, the hybrid device is designed and measured the electrochemical properties. The hybrid device showed the remarkable Qs of 1528 C.g−1, power density (Pd) of 2347 Wkg−1 and an energy density (Ed) of 34.99 Whkg−1. Further, the VCuS/MXene//AC device is measured up to 6000 cycles to check the stability and durability. The device showed the capacity retention (CR) of 88.5% and a high Coulombic efficiency of 82.6%. Additionally, the VCuS/MXene electrode material is utilized as an electrochemical glucose sensor for the precise detection of H2O2 down to a minimal concentration of H2O2/mm, exhibiting exceptional precision. The use of multifunctional VCuS/MXene nanocomposite electrode material presents novel possibilities for the construction of hybrid energy harvesting systems.
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5. |
- Sallam, Malik, et al.
(författare)
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Language discrepancies in the performance of generative artificial intelligence models : an examination of infectious disease queries in English and Arabic
- 2024
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Ingår i: BMC Infectious Diseases. - 1471-2334. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Assessment of artificial intelligence (AI)-based models across languages is crucial to ensure equitable access and accuracy of information in multilingual contexts. This study aimed to compare AI model efficiency in English and Arabic for infectious disease queries. Methods: The study employed the METRICS checklist for the design and reporting of AI-based studies in healthcare. The AI models tested included ChatGPT-3.5, ChatGPT-4, Bing, and Bard. The queries comprised 15 questions on HIV/AIDS, tuberculosis, malaria, COVID-19, and influenza. The AI-generated content was assessed by two bilingual experts using the validated CLEAR tool. Results: In comparing AI models’ performance in English and Arabic for infectious disease queries, variability was noted. English queries showed consistently superior performance, with Bard leading, followed by Bing, ChatGPT-4, and ChatGPT-3.5 (P =.012). The same trend was observed in Arabic, albeit without statistical significance (P =.082). Stratified analysis revealed higher scores for English in most CLEAR components, notably in completeness, accuracy, appropriateness, and relevance, especially with ChatGPT-3.5 and Bard. Across the five infectious disease topics, English outperformed Arabic, except for flu queries in Bing and Bard. The four AI models’ performance in English was rated as “excellent”, significantly outperforming their “above-average” Arabic counterparts (P =.002). Conclusions: Disparity in AI model performance was noticed between English and Arabic in response to infectious disease queries. This language variation can negatively impact the quality of health content delivered by AI models among native speakers of Arabic. This issue is recommended to be addressed by AI developers, with the ultimate goal of enhancing health outcomes.
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6. |
- Glasbey, JC, et al.
(författare)
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- 2021
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7. |
- Bravo, L, et al.
(författare)
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- 2021
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8. |
- Tabiri, S, et al.
(författare)
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- 2021
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