246 research outputs found
Materials for electrochemiluminescence : TADF, hydrogen-bonding, and aggregation- and crystallization-induced emission luminophores
Authors thank the Natural Sciences and Engineering Research Council Canada (NSERC, DG RGPIN-2018- 06556, DG RGPIN-2023-05337 and SPG STPGP-2016-493924), New Frontiers in Research Fund (NFRFR-2021-00272), Canada Foundation of Innovation/Ontario Innovation Trust (CFI/OIT, 9040) and The University of Western Ontario for the support to this research. KC is an Ontario Graduate Scholar.Electrochemiluminescence (ECL) is a rapidly growing discipline with many analytical applications from immunoassays to single-molecule detection. At the forefront of ECL research is materials chemistry, which looks at engineering new materials and compounds exhibiting enhanced ECL efficiencies compared to conventional fluorescent materials. In this review, we summarize recent molecular design strategies that lead to high efficiency ECL. In particular, we feature recent advances in the use of thermally activated delayed fluorescence (TADF) emitters to produce enhanced electrochemiluminescence. We also document how hydrogen bonding, aggregation, and crystallization can each be recruited in the design of materials showing enhanced electrochemiluminescence.Publisher PDFPeer reviewe
Enhanced electrochemiluminescence from a stoichiometric ruthenium(II)-iridium(III) complex soft salt
The authors thank NSERC, CFI, FQRNT, PREA, and The University of Western Ontario for generous financial support to this research.Electrochemiluminescence (ECL) and electrochemistry are reported for a heterometallic soft salt, [Ru(dtbubpy)3][Ir(ppy)2(CN)2]2 ([Ir][Ru][Ir]), consisting of a 2:1 ratio of complementary charged Ru and Ir complexes possessing two different emission colors. The [Ru]2+ and [Ir]ā moieties in the [Ir][Ru][Ir] greatly reduce the energy required to produce ECL. Though ECL intensity in the annihilation path was enhanced 18Ć relative to that of [Ru(bpy)3]2+, ECL in the co-reactant path with tri-n-propylamine was enhanced a further 4Ć. Spooling spectroscopy gives insight into ECL mechanisms: the unique light emission at 634ā
nm is due to the [Ru]2+* excited state and no [Ir]ā* was generated in either route. Overall, the soft salt system is anticipated to be attractive and suitable for the development of efficient and low-energy-cost ECL detection systems.PostprintPeer reviewe
Hierarchical Fashion Design with Multi-stage Diffusion Models
Cross-modal fashion synthesis and editing offer intelligent support to
fashion designers by enabling the automatic generation and local modification
of design drafts.While current diffusion models demonstrate commendable
stability and controllability in image synthesis,they still face significant
challenges in generating fashion design from abstract design elements and
fine-grained editing.Abstract sensory expressions, \eg office, business, and
party, form the high-level design concepts, while measurable aspects like
sleeve length, collar type, and pant length are considered the low-level
attributes of clothing.Controlling and editing fashion images using lengthy
text descriptions poses a difficulty.In this paper, we propose HieraFashDiff,a
novel fashion design method using the shared multi-stage diffusion model
encompassing high-level design concepts and low-level clothing attributes in a
hierarchical structure.Specifically, we categorized the input text into
different levels and fed them in different time step to the diffusion model
according to the criteria of professional clothing designers.HieraFashDiff
allows designers to add low-level attributes after high-level prompts for
interactive editing incrementally.In addition, we design a differentiable loss
function in the sampling process with a mask to keep non-edit
areas.Comprehensive experiments performed on our newly conducted Hierarchical
fashion dataset,demonstrate that our proposed method outperforms other
state-of-the-art competitors
Simple and Fast Fabrication Methodology for Platinum and Carbon Ultramicroelectrodes (UME) in Scanning Electrochemical Microscopy (SECM)
Scanning electrochemical microscopy (SECM) is a highly versatile method for measuring and imaging a wide range of systems. When paired with an intricately made ultramicroelectrode (UME) probe, SECM becomes an even more powerful tool for imaging microscale features in a system. However, purchasing these UMEās comes at a high cost with less ability for modification. Having high quality UMEās expands the ability of SECM and enables precise measuring and imaging in a wide range of applications such as solar cells in Dr. Dingās lab, and corroding metals in Dr. Gatemanās lab. To combat this issue of high cost and set specifications, a simple and fast methodology for preparing UMEās was developed
Learning Granularity-Unified Representations for Text-to-Image Person Re-identification
Text-to-image person re-identification (ReID) aims to search for pedestrian
images of an interested identity via textual descriptions. It is challenging
due to both rich intra-modal variations and significant inter-modal gaps.
Existing works usually ignore the difference in feature granularity between the
two modalities, i.e., the visual features are usually fine-grained while
textual features are coarse, which is mainly responsible for the large
inter-modal gaps. In this paper, we propose an end-to-end framework based on
transformers to learn granularity-unified representations for both modalities,
denoted as LGUR. LGUR framework contains two modules: a Dictionary-based
Granularity Alignment (DGA) module and a Prototype-based Granularity
Unification (PGU) module. In DGA, in order to align the granularities of two
modalities, we introduce a Multi-modality Shared Dictionary (MSD) to
reconstruct both visual and textual features. Besides, DGA has two important
factors, i.e., the cross-modality guidance and the foreground-centric
reconstruction, to facilitate the optimization of MSD. In PGU, we adopt a set
of shared and learnable prototypes as the queries to extract diverse and
semantically aligned features for both modalities in the granularity-unified
feature space, which further promotes the ReID performance. Comprehensive
experiments show that our LGUR consistently outperforms state-of-the-arts by
large margins on both CUHK-PEDES and ICFG-PEDES datasets. Code will be released
at https://github.com/ZhiyinShao-H/LGUR.Comment: Accepted by ACM Multimedia 202
Near-Infrared Photoluminescence and Electrochemiluminescence from an Exceptionally Simple Boron Difluoride Formazanate Dye
Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence and electrochemiluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S1-S0 energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical properties were probed using cyclic voltammetry and revealed four electrochemically reversible waves. Electrochemiluminescence properties were examined in the presence of tri-n-propylamine, leading to maximum intensity at 910 nm, at least 85 nm (1132 cmā1) red-shifted compared to all other organic dyes. This work sets the stage for the development of future generations of dyes for emerging applications, including single-cell imaging, that require near-infrared photoluminescence and electrochemiluminescence
Effect of dexmedetomidine on miR-144-3p expression and epithelial mesenchymal transition in gastric cancer cells
Purpose: To investigate the effect of dexmedetomidine (DEX) on epithelial mesenchymal transition (EMT) in gastric cancer cells, and the role of microRNA-144-3p (miR-144-3p) in the process.Methods: The effect of DEX on miRNA expression profile was analyzed using GEO database(https://www.ncbi.nlm.nih.gov/gds/). Human gastric cancer cells were cultured in vitro, and one group of cells was treated with saline for 48 h (control group). Cells treated with DEX at doses of 0.01, 0.1 and 1.0 Ī¼mol/L for 48 h were marked as low-, medium- and high-DEX concentration groups. The mRNA expression levels of miR-144-3p, ZEB1, E-cadherin and vimentin were determined using real-time quantitative polymerase chain reaction (RT-PCR), while the protein expressions of ZEB1, E-cadherin and vimentin were assayed with Western blotting. Cell proliferation was determined with CCK-8 assay, while metastasis was measured using Transwell assay.Results: The GEO database demonstrated that the expression of miR-144-3p in rat cardiomyocytes was significantly decreased after DEX treatment (p < 0.05). The expression of miR-144-3p was decreased in all groups, when compared to the control group, but the expressions of ZEB1 and vimentin were increased, while that of E-cadherin was down-regulated (p < 0.05). Cell proliferation in the high-DEX concentration group was decreased (p < 0.05). The degrees of cell invasion and migration were increased in the medium- and high-DEX concentration groups (p < 0.05).Conclusion: DEX promotes the metastasis of gastric cancer cells by regulation of epithelialmesenchymal transition (EMT) and the expression of miR-144-3p. This finding provides a new insight into the treatment of gastric cancer
Insights into enhanced electrochemiluminescence of a multiresonance thermally activated delayed fluorescence molecule
Funding: Walloon Region, Grant/Award Number:n1117545; Leverhulme Trust, Grant/Award Numbers: RPGā2016047,SRF\R1\201089; Natural Sciences and Engineering Research Council Canada, Grant/Award Numbers: DG RGPINā2018ā06556, SPG STPGPā2016ā493924; Fonds dela Recherche Scientifiques de Belgique, Grant/Award Numbers: 2.5020.11,F.4534.21; Engineering and Physical Sciences Research Council, Grant/Award Number: EP/P010482/1.The electrochemiluminescence (ECL) behavior of a multiresonance thermally activated delayed fluorescence molecule has been investigated for the first time by means of ECL-voltage curves, newly designed ECL-time observatory, and ECL spectroscopy. The compound, Mes3DiKTa, shows complex ECL behavior, including a delayed onset time of 5āms for ECL generation in both the annihilation pathway and the coreactant route, which we attribute to organic long-persistent ECL (OLECL). Triplet-triplet annihilation, thermally activated delayed fluorescence and uncompensated solution resistance cannot be ruled out as contributing mechanisms to the ECL. A very long ECL emission decay was attributed to OLECL as well. The absolute ECL efficiencies of Mes3DiKTa were enhanced and reached 0.0013% in annihilation route and 1.1% for the coreactant system, which are superior to those of most other organic ECL materials. It is plausible that ECL materials with comparable behavior as Mes3DiKTa are desirable in applications such as ECL sensing, imaging, and light-emitting devices.Publisher PDFPeer reviewe
Electrochemical assessment of water|ionic liquid biphasic systems towards cesium extraction from nuclear waste
A room temperature ionic liquid (IL) composed of a quaternary alkylphosphonium (trihexyltetradecylphosphonium, P66614(+)) and tetrakis(pentafluorophenyl) borate anion (TB) was employed within a water| P66614TB (w|P66614TB or w|IL) biphasic system to evaluate cesium ion extraction in comparison to that with a traditional water|organic solvent (w|o) combination. Cs-137 is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is therefore of considerable importance. The extraction was facilitated by the ligand octyl(phenyl)-N, N'-diisobutylcarbamoylphosphine oxide (CMPO) used in TRans- Uranium EXtraction processes and investigated through well established liquid| liquid electrochemistry. This study gave access to the metal ion to ligand (1: n) stoichiometry and overall complexation constant, beta, of the interfacial complexation reaction which were determined to be 1: 3 and 1.6 x 10(11) at the w| P66614TB interface while the study at w|o elicited an n equal to 1 with beta equal to 86.5. Through a straightforward relationship, these complexation constant values were converted to distribution coefficients, da, with the ligand concentrations studied for comparison to other studies present in the literature; the w|o and w|IL systems gave delta(alpha) of 2 and 8.2 x 10(7), respectively, indicating a higher overall extraction efficiency for the latter. For the w|o system, the metal ion-ligand stoichiometries were confirmed through isotopic distribution analysis of mass spectra obtained by the direct injection of an emulsified water-organic solvent mixture into an electron spray ionization mass spectrometer. (c) 2014 Elsevier B.V. All rights reserved
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