| 1. |
- Chong, Hui, et al.
(författare)
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Organo-ptii complexes for potent photodynamic inactivation of multi-drug resistant bacteria and the influence of configuration
- 2024
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Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 11:14
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Tidskriftsartikel (refereegranskat)abstract
- PtII based organometallic photosensitizers (PSs) have emerged as novel potent photodynamic inactivation (PDI) reagents through their enhanced intersystem crossing (ISC) processes. Currently, few PtII PSs have been investigated as antibacterial materials, with relatively poor performances reported and with structure-activity relationships not well described. Herein, a pair of configurational isomers are reported of Bis-BODIPY (4,4-difluoro-boradizaindacene) embedded PtII PSs. The cis-isomer (cis-BBP) displayed enhanced 1O2 generation and better bacterial membrane anchoring capability as compared to the trans-isomer (trans-BBP). The effective PDI concentrations (efficiency > 99.9%) for cis-BBP in Acinetobacter baumannii (multi-drug resistant (MDR)) and Staphylococcus aureus are 400 nM (12 J cm−2) and 100 nM (18 J cm−2), respectively; corresponding concentrations and light doses for trans-BBP in the two bacteria are 2.50 µM (30 J cm−2) and 1.50 µM (18 J cm−2), respectively. The 50% and 90% minimum inhibitory concentration (MIC50 and MIC90) ratio of trans-BBP to cis-BBP is 22.22 and 24.02 in A. baumannii (MDR); 21.29 and 22.36 in methicillin resistant S. aureus (MRSA), respectively. Furthermore, cis-BBP displays superior in vivo antibacterial performance, with acceptable dark and photoinduced cytotoxicity. These results demonstrate cis-BBP is a robust light-assisted antibacterial reagent at sub-micromolecular concentrations. More importantly, configuration of PtII PSs should be an important issue to be considered in further PDI reagents design.
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| 2. |
- Li, Siyu, et al.
(författare)
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A serious game with avatar suspects can be used to train naive participants in the Strategic Use of Evidence
- 2024
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Ingår i: Journal of Forensic Psychology: Research and Practice.
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we developed a serious game with computer-generated avatars (i.e., Avatar Training) driven by empirically-based algorithms of suspect behavior to train participants in using the Evidence Framing Matrix (EFM), an essential tactical component of the SUE technique. Ninety-six participants were randomly allocated into four groups (i.e., Control, Training, Feedback, and Training & Feedback groups) and conducted two interviews. Compared to untrained participants, EFM-trained participants used the EFM to a higher degree in the first interview. Receiving feedback increased the ability to use the EFM in the second interview. Furthermore, combining the theoretical training with feedback made participants use within-statement (in)consistencies more when evaluating avatar statements. The results show that naive participants can be trained to use the EFM using algorithm-driven suspect avatars, suggesting there is potential for using avatars as a scalable approach in the learning of interview techniques with suspects.
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| 3. |
- Li, Siyu, et al.
(författare)
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Dearomatization drives complexity generation in freshwater organic matter
- 2024
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Ingår i: Nature. - : NATURE PORTFOLIO. - 0028-0836 .- 1476-4687. ; 628:8009
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Tidskriftsartikel (refereegranskat)abstract
- Dissolved organic matter (DOM) is one of the most complex, dynamic and abundant sources of organic carbon, but its chemical reactivity remains uncertain 1-3 . Greater insights into DOM structural features could facilitate understanding its synthesis, turnover and processing in the global carbon cycle 4,5 . Here we use complementary multiplicity-edited 13C nuclear magnetic resonance (NMR) spectra to quantify key substructures assembling the carbon skeletons of DOM from four main Amazon rivers and two mid-size Swedish boreal lakes. We find that one type of reaction mechanism, oxidative dearomatization (ODA), widely used in organic synthetic chemistry to create natural product scaffolds 6-10 , is probably a key driver for generating structural diversity during processing of DOM that are rich in suitable polyphenolic precursor molecules. Our data suggest a high abundance of tetrahedral quaternary carbons bound to one oxygen and three carbon atoms (OCqC3 units). These units are rare in common biomolecules but could be readily produced by ODA of lignin-derived and tannin-derived polyphenols. Tautomerization of (poly)phenols by ODA creates non-planar cyclohexadienones, which are subject to immediate and parallel cycloadditions. This combination leads to a proliferation of structural diversity of DOM compounds from early stages of DOM processing, with an increase in oxygenated aliphatic structures. Overall, we propose that ODA is a key reaction mechanism for complexity acceleration in the processing of DOM molecules, creation of new oxygenated aliphatic molecules and that it could be prevalent in nature. Using complementary multiplicity-edited 13C nuclear magnetic resonance spectra, oxidative dearomatization is shown to be a key driver for generating structural diversity during processing of dissolved organic matter and the data also suggest high abundance of OCqC3 units.
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| 4. |
- Liu, Siyu, et al.
(författare)
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A TDLAS-based photofragmentation method for spatially resolved measurement of KOH and KCl as well as its application in biomass combustion processes
- 2024
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Ingår i: Fuel. - 0016-2361. ; 357
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Tidskriftsartikel (refereegranskat)abstract
- The release of gas-phase potassium species, mainly KOH, KCl, and K atoms, from burning biomass fuels can introduce severe problems to boilers, such as fouling, slagging, and corrosion. In the present work, an optical technique combining laser-induced photofragmentation and tunable diode laser absorption spectroscopy is developed for simultaneously measuring the concentration of KOH, KCl and K atoms with a high temporal and spatial resolution. Two laser sheets with a thickness of about 1 mm at wavelengths of 266 and 355 nm, respectively, were adopted to photodissociate KOH and KCl molecules into K atoms. A continuous wave laser at 766 nm generated by a tunable diode laser passed perpendicularly through the laser sheet to detect the K atom. The measured fragmentation-induced K-atom absorbance was correlated to KOH and KCl concertation through a calibration process in a homogenous combustion environment where the concentrations of KOH and KCl were monitored by UV absorption spectroscopy. The calibration curves were verified to be independent of temperature. A typical spatial resolution of 1 mm3 was realized where the value depended on the overlap volume of the UV laser sheet and the 766 nm laser beam. Finally, this technique was applied to measure the release behavior of KOH, KCl and K atoms from burning wood and straw pellets.
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| 5. |
- Wang, Zhihua, et al.
(författare)
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Alkali metal release in thermochemical conversion of biomass and coal : Optical measurements and modeling
- 2024
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Ingår i: Progress in Energy and Combustion Science. - 0360-1285. ; 100
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Forskningsöversikt (refereegranskat)abstract
- Alkali metals, mainly K and Na, which are present in solid fuels such as biomass and coal, play an important role during their thermal conversion, e.g., in combustion or gasification. At high temperatures, alkali elements will be released in gas phase as alkali atoms, alkali chlorides, alkali hydroxides and alkali sulphates. In biomass/coal-fired boilers, the release of these alkali species can cause problems such as corrosion, slagging and fouling, threatening the safe operation of the facilities. The information on the release dynamic is important for developing proper models for alkali metal transformation in solid fuel combustion and gasification. Therefore, accurate quantitative measurements of the release of different alkali species during thermal-chemical conversion processes of biomass/coal are important. In this paper, we review literatures published over the last few decades in the field of quantitative optical measurements of alkali metals performed in combustion/gasification processes, and the release modeling based on those optical measurements. Firstly, the current situation of biomass and coal utilization is discussed, including the speciation of alkali metals in biomass/coal and their adverse effects on facilities. Secondly, requirements for optical measurements as well as several quantitative optical techniques are introduced including the general principles, typical setups, calibration methods and major advantages and drawbacks. In contrast to off-line techniques, these optical techniques provide nonintrusive measurements with high temporal and spatial resolution, which are indispensable for alkali release modeling. Furthermore, the alkali release behaviors based on optical measurements in thermochemical conversion processes are discussed. Based on the experimental results, the kinetic data for alkali release were summarized. Alkali release modeling was fulfilled relying on the knowledge of alkali release mechanisms and the kinetic data. In addition, simulations of alkali metal release with computational fluid dynamics during the biomass/coal combustion processes are also discussed, providing valuable information for industrial processes. Finally, typical examples of industrial applications of optical measurement methods in solid fuel thermochemical conversion processes as well as waste incineration and other processes are presented.
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