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| 2. |
- Sid Ahmed, Mazen A., et al.
(författare)
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Prevalence and microbiological and genetic characteristics of multidrug-resistant Pseudomonas aeruginosa over three years in Qatar
- 2022
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Ingår i: Antimicrobial stewardship & healthcare epidemiology : ASHE. - : Norsk förening for epidemiologi. - 2732-494X .- 2732-494X. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Antimicrobial resistance (AMR) is a global priority with significant clinical and economic consequences. Multidrug-resistant (MDR) Pseudomonas aeruginosa is one of the major pathogens associated with significant morbidity and mortality. In healthcare settings, the evaluation of prevalence, microbiological characteristics, as well as mechanisms of resistance is of paramount importance to overcome associated challenges.METHODS: Consecutive clinical specimens of P. aeruginosa were collected prospectively from 5 acute-care and specialized hospitals between October 2014 and September 2017, including microbiological, clinical characteristics and outcomes. Identification and antimicrobial susceptibility test were performed using the BD Phoenix identification and susceptibility testing system, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and minimum inhibitory concentration (MIC) test strips. Overall, 78 selected MDR P. aeruginosa isolates were processed for whole-genome sequencing (WGS).RESULTS: The overall prevalence of MDR P. aeruginosa isolates was 5.9% (525 of 8,892) and showed a decreasing trend; 95% of cases were hospital acquired and 44.8% were from respiratory samples. MDR P. aeruginosa demonstrated >86% resistance to cefepime, ciprofloxacin, meropenem, and piperacillin-tazobactam but 97.5% susceptibility to colistin. WGS revealed 29 different sequence types: 20.5% ST235, 10.3% ST357, 7.7% ST389, and 7.7% ST1284. ST233 was associated with bloodstream infections and increased 30-day mortality. All ST389 isolates were obtained from patients with cystic fibrosis. Encoded exotoxin genes were detected in 96.2% of isolates.CONCLUSIONS: MDR P. aeruginosa isolated from clinical specimens from Qatar has significant resistance to most agents, with a decreasing trend that should be explored further. Genomic analysis revealed the dominance of 5 main clonal clusters associated with mortality and bloodstream infections. Microbiological and genomic monitoring of MDR P. aeruginosa has enhanced our understanding of AMR in Qatar.
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| 3. |
- Elawad, M., et al.
(författare)
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Enhanced performance of perovskite solar cells using p-type doped PFB:F4TCNQ composite as hole transport layer
- 2019
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Ingår i: Journal of Alloys and Compounds. - : Elsevier. - 0925-8388 .- 1873-4669. ; 771, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- Conjugated polymers have been widely used as hole transport materials (HTM) in the preparation of mesoscopic perovskite solar cells (PSCs). In this work, we employed p-type doped conducting polymer known as poly(9,9-dioctylfluorene-co-bis-N,N-(-4-butyl phenyl)-bis-N,N-phenyl-1,4-phenylenediamine) (PFB) as a hole transport material (HTM) in perovskite based solar cell. The effect of dopant concentration on the optical and electrical properties of PEB was investigated to optimize the electrical properties of the material for the best function of the solar cell. The highest power conversion efficiency of mesoscopic perovskite solar cells (PSCs), fabricated in this investigation, was found to be 14.04% which is 57% higher than that of pristine PFB hole transport layer. The UV–Vis absorption and Raman spectroscopy measurements confirm the occurrence of oxidation in a p-type doped PFB hole transport layer. This is attributed to the transfer of electrons from the highest occupied molecular orbital (HOMO) of PEB to the lowest unoccupied molecular orbital (LUMO) of F4TCNQ. The solar cells produced using p-type doped PFB:F4TCNQ composite not only improves device performances but also shows superior long-term stability. The optical, morphological and electrical properties of the doped composite PFB: F4TCNQ and newly fabricated devices are presented and discussed in this paper.
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| 4. |
- Arbab, A., et al.
(författare)
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Evaluation of gas mixtures with high-temperature gas sensors based on silicon carbide
- 1994
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 19:1-3, s. 562-565
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Tidskriftsartikel (refereegranskat)abstract
- Field-effect devices with a catalytic metal gate are operated as gas sensors over a large temperature range by the use of 6H-silicon carbide (bandgap 2.9 eV) instead of silicon (1.1 eV) as the semiconducting material. We have produced metal-silicon dioxide-silicon carbide (MOSiC) capacitors with platinum as the gate metal that can be operated above 800-degrees-C. The sensitivity of the Pt-MOSiC devices to hydrogen and hydrocarbons was tested in various oxygen atmospheres. The response to mixtures of hydrogen and saturated hydrocarbons indicated the existence of two different sensing mechanisms.
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| 5. |
- Arbab, A., et al.
(författare)
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Gas sensors for high temperature operation based on metal oxide silicon carbide (MOSiC) devices
- 1993
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 15:1-3, s. 19-23
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Tidskriftsartikel (refereegranskat)abstract
- Catalytic metal gate-silicon dioxide-silicon carbide (MOSiC) capacitors operating to about 800-degrees-C are used as high temperature gas sensor devices. Hydrogen or hydrogen containing molecules, which are dissociated on the catalytic metal surface, create a decrease of the flat band voltage of the MOS capacitor. The MOSiC devices with a platinum gate respond to saturated hydrocarbons in air at concentrations well below the explosion limits.
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| 6. |
- Jung, Ivar, 1952-, et al.
(författare)
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Colour Associations in Different Cultures
- 2018
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Ingår i: Proceedings of the International Colour Association (AIC) Conference 2018. - Newtown : The International Colour Association. - 9780648472407 ; , s. 503-508
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to investigate if there are colours that are associated with certain words. The study was conducted in nine countries (Germany, Iran, Japan, Nepal, Russia, Saudi Arabia, Sweden, Turkey and Uganda) to see if there are cultural differences in the way people associate colours with the words. The subjects were asked to match each of the words with only one colour. They could choose colours from the chart consisting of 27 colour samples selected from the NCS Atlas. In total, the dataset included 18,072 responses from 753 participants. The collected data were analysed by hue, chromaticness and the degree of blackness and whiteness. The results show that the colour associations with the words vary to different extent between the different countries. That indicates that there are universal associations with colours for some of the words, as well as cultural differences.
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| 7. |
- Khan, Bangul, et al.
(författare)
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Recent progress in thermosensitive hydrogels and their applications in drug delivery area
- 2023
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Ingår i: MedComm – Biomaterials and Applications. - 2769-643X .- 2769-643X. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- The scientific community has widely recognized thermosensitive hydrogelsas highly biocompatible material withimmense potential in drug deliverysystems. When the temperature of these hydrogels approaches that ofhuman body, a phase change occurs, enhancing their usefulness in a rangeof medical scenarios. This review article highlighted the background ofthermosensitive hydrogels, their properties, and their applications intransdermal, oral, ophthalmic, intravaginal, nasal, rectal, cancer therapy,and cell‐loaded drug delivery systems. The literature suggests numerousadvantages of these hydrogels over conventional drug delivery systems andfind applications in various fields, such as therapeutic systems, fillingprocesses, and sustained drug delivery systems. One of their key benefits isthe ability to eliminate invasive procedures like surgery, providing anoninvasive alternative for drug administration. Moreover,theystreamlinethe formulation process for both hydrophilic and hydrophobic drugdelivery systems, simplifying the development of effective treatments.The thermosensitive hydrogels have been found to be green materials withnegligible side effects and desirable drug delivery properties. Thethermosensitive hydrogel's sustained‐release characteristics, immunogenic-ity, and biodegradability have also gained increased interest. Some of thedisadvantages of thermosensitive hydrogels include delayed temperatureresponse, weak mechanical characteristics, and poor biocompatibility,which limits their potential use in drug delivery applications.
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| 8. |
- Zeng, Jiao, et al.
(författare)
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High-resolution structure of a fish aquaporin reveals a novel extracellular fold
- 2022
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Ingår i: Life Science Alliance. - : Life Science Alliance, LLC. - 2575-1077. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Aquaporins are protein channels embedded in the lipid bilayer in cells from all organisms on earth that are crucial for water homeostasis. In fish, aquaporins are believed to be important for osmoregulation; however, the molecular mechanism behind this is poorly understood. Here, we present the first structural and functional characterization of a fish aquaporin; cpAQP1aa from the fresh water fish climbing perch (Anabas testudineus), a species that is of high osmoregulatory interest because of its ability to spend time in seawater and on land. These studies show that cpAQP1aa is a water-specific aquaporin with a unique fold on the extracellular side that results in a constriction region. Functional analysis combined with molecular dynamic simulations suggests that phosphorylation at two sites causes structural perturbations in this region that may have implications for channel gating from the extracellular side.
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