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1.
Int J Biol Macromol ; 254(Pt 3): 127892, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37952799

RESUMEN

Underwater superoleophobic (UWSO) materials have garnered significant attention in separating oil/water mixtures. But, the majority of these materials are made from non-degradable and non-renewable raw materials, polluting the environment and wasting scarce resources while using them. Against this backdrop, this study aimed to fabricate an environmental-friendly UWSO textile using biobased materials. To achieve this, hydrogel consisting of chitosan (CS) and poly(tannic acid) (PTA) were formed and coated on cotton fabric (CTF) via dip-coating followed by oxidative polymerization. CS&PTA hydrogel endowed the CTF with a rough surface and high surface energy, leading to an UWSO CTF with an underwater oil contact angle as high as 166.84°. The CS&PTA/CTF had excellent separation capability toward various oil/water mixtures, showing separation efficiency above 99.84 % and water flux higher than 23, 999 L m-2 h-1. Moreover, CS&PTA/CTF possessed excellent mechanical and environmental stability with underwater superoleophobicity unchanged after sandpaper friction, ultrasonication, organic solvents, NaCl (m/v, 30 %) solution, and acid/base solution immersion, due to the strong interaction between the hydrogel and cotton fabric generated by the mussel-inspired adhesion owing to the presence of PTA. The fully biobased UWSO CTF exhibits great promising to be an alternative to traditional superwetting materials for separation of oil/water mixtures.


Asunto(s)
Quitosano , Hidrogeles , Humanos , Caquexia , Textiles
2.
Environ Sci Technol ; 57(49): 20905-20914, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38010209

RESUMEN

NOx storage-reduction (NSR), a promising approach for removing NOx pollutants from diesel vehicles, remains elusive to cope with the increasingly lower exhaust temperatures (especially below 250 °C). Here, we develop a conceptual electrified NSR strategy, where electricity with a low input power (0.5-4 W) is applied to conductive Pt and K co-supported antimony-doped tin oxides (Pt-K/ATO), with C3H6 as a reductant. The ignition temperature for 10% NOx conversion is nearly 100 °C lower than that of the traditional thermal counterpart. Furthermore, reducing the power in the fuel-lean period relative to that in the fuel-rich period increases the maximum energy efficiency by 23%. Electrically driven release of lattice oxygen is revealed to play vital roles in multiple steps in NSR, including NO adsorption, desorption, and reduction, for improved NSR activity. This work provides an electrification strategy for developing high-activity NSR catalysis utilizing electricity onboard hybrid vehicles.


Asunto(s)
Contaminantes Atmosféricos , Óxidos de Nitrógeno , Óxidos de Nitrógeno/análisis , Temperatura , Estaño , Antimonio , Óxidos , Emisiones de Vehículos/análisis , Catálisis , Contaminantes Atmosféricos/análisis
3.
Nanomaterials (Basel) ; 13(20)2023 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-37887935

RESUMEN

A sulfur-containing metal-organic framework, donated as UiO-66-NSMe, was prepared by the post-synthetic modification (PSM) of UiO-66-NH2 with 2-(Methylthio)benzaldehyde, and the successful synthesis of PSM was confirmed by X-ray photoelectron spectroscopy (XPS), FT-IR and 1H NMR studies. According to the characteristics of mercury thiophilic, UiO-66-NSMe could be used as a luminescent sensor for Hg2+ detection with a high selectivity and sensitivity (Ksv = 2.5 × 104 M-1; LOD = 20 nM), which could be attributed to the coordination between sulfur sites and Hg2+ based on XPS results. In practical applications, UiO-66-NSMe yielded satisfactory recovery rates (ranging from 96.1% to 99.5%) when it was employed for detecting Hg2+ in spiked environmental samples. Furthermore, UiO-66-NSMe was successfully employed to detect mercury (II) residues with the in situ rapid nondestructive imaging in simulated fresh agricultural products. Thus, this PSM strategy could provide good guidance for environmental protection methodologies in the future.

4.
Proc Natl Acad Sci U S A ; 120(33): e2211019120, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37552757

RESUMEN

Polymorphisms in immunity genes can have large effects on susceptibility to infection. To understand the origins of this variation, we have investigated the genetic basis of resistance to the parasitoid wasp Leptopilina boulardi in Drosophila melanogaster. We found that increased expression of the gene lectin-24A after infection by parasitic wasps was associated with a faster cellular immune response and greatly increased rates of killing the parasite. lectin-24A encodes a protein that is strongly up-regulated in the fat body after infection and localizes to the surface of the parasite egg. In certain susceptible lines, a deletion upstream of the lectin-24A has largely abolished expression. Other mutations predicted to abolish the function of this gene have arisen recurrently in this gene, with multiple loss-of-expression alleles and premature stop codons segregating in natural populations. The frequency of these alleles varies greatly geographically, and in some southern African populations, natural selection has driven them near to fixation. We conclude that natural selection has favored the repeated loss of an important component of the immune system, suggesting that in some populations, a pleiotropic cost to lectin-24A expression outweighs the benefits of resistance.


Asunto(s)
Parásitos , Avispas , Animales , Drosophila/genética , Drosophila melanogaster/genética , Interacciones Huésped-Parásitos , Avispas/fisiología , Lectinas/genética , Selección Genética
5.
Materials (Basel) ; 16(16)2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37629911

RESUMEN

Ternary organic solar cells (OSCs) have attracted intensive studies due to their promising potential for attaining high-performing photovoltaics, whereas there has been an opening challenge in minimizing the open circuit voltage (Voc) loss while retaining the optimal carrier extraction in the multiple mixture absorbers. Here, we systemically investigate a ternary absorber comprised of two acceptors and a donor, in which the resultant Voc and fill factor are varied and determined by the ratios of acceptor components as a result of the unbalance of non-radiative recombination rates and charge transport. The transient absorption spectroscopy and electroluminescence techniques verify two distinguishable charge-transfer (CT) states in the ternary absorber, and the mismatch of non-radiative recombination rates of those two CT states is demonstrated to be associated with the Voc deficit, whilst the high-emissive acceptor molecule delivers inferior electron mobility, resulting in poor charge transport and a subpar fill factor. These findings enable us to optimize the mixture configuration for attaining the maximal-performing devices. Our results not only provide insight into maximizing the photovoltage of organic solar cells but can also motivate researchers to further unravel the photophysical mechanisms underlying the intermolecular electronic states of organic semiconductors.

6.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 40(2): 327-334, 2023 Apr 25.
Artículo en Chino | MEDLINE | ID: mdl-37139765

RESUMEN

The neural stimulator is a core component of animal robots. While the control effect of animal robots is influenced by various factors, the performance of the neural stimulator plays a decisive role in regulating animal robots. In order to optimize animal robots, embedded neural stimulators had been developed using flexible printed circuit board technology. This innovation not only enabled the stimulator to generate parameter-adjustable biphasic current pulses through control signals, but also optimized its carrying mode, material, and size, overcoming the disadvantages of traditional backpack or head-inserted stimulators, which have poor concealment and are prone to infection. Static, in vitro, and in vivo performance tests of the stimulator demonstrated that it not only had precise pulse waveform output capability, but also was lightweight and small in size. It had excellent in vivo performance in both laboratory and outdoor environments. Our study has high practical significance for the application of animal robots.


Asunto(s)
Robótica , Animales
7.
PLoS Pathog ; 19(1): e1011117, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36719928

RESUMEN

Aedes aegypti mosquitoes carrying self-spreading, virus-blocking Wolbachia bacteria are being deployed to suppress dengue transmission. However, there are challenges in applying this technology in extreme environments. We introduced two Wolbachia strains into Ae. aegypti from Saudi Arabia for a release program in the hot coastal city of Jeddah. Wolbachia reduced infection and dissemination of dengue virus (DENV2) in Saudi Arabian mosquitoes and showed complete maternal transmission and cytoplasmic incompatibility. Wolbachia reduced egg hatch under a range of environmental conditions, with the Wolbachia strains showing differential thermal stability. Wolbachia effects were similar across mosquito genetic backgrounds but we found evidence of local adaptation, with Saudi Arabian mosquitoes having lower egg viability but higher adult desiccation tolerance than Australian mosquitoes. Genetic background effects will influence Wolbachia invasion dynamics, reinforcing the need to use local genotypes for mosquito release programs, particularly in extreme environments like Jeddah. Our comprehensive characterization of Wolbachia strains provides a foundation for Wolbachia-based disease interventions in harsh climates.


Asunto(s)
Aedes , Dengue , Wolbachia , Animales , Arabia Saudita , Australia , Ambientes Extremos
8.
Adv Sci (Weinh) ; 9(25): e2201150, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35822668

RESUMEN

Four isomeric, homoleptic iridium(III) metal complexes bearing 5-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene and 6-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene-based cyclometalating chelates are successfully synthesized. The meridional isomers can be converted to facial isomers through acid induced isomerization. The m-isomers display a relatively broadened and red-shifted emission, while f-isomers exhibit narrowed blue emission band, together with higher photoluminescent quantum yields and reduced radiative lifetime relative to the mer-counterparts. Maximum external quantum efficiencies of 13.5% and 22.8% are achieved for the electrophosphorescent devices based on f-tpb1 and m-tpb1 as dopant emitter together with CIE coordinates of (0.15, 0.23) and (0.22, 0.45), respectively. By using f-tpb1 as the sensitizing phosphor and t-DABNA as thermally activated delayed fluorescence (TADF) terminal emitter, hyperluminescent OLEDs are successfully fabricated, giving high efficiency of 29.6%, full width at half maximum (FWHM) of 30 nm, and CIE coordinates of (0.13, 0.11), confirming the efficient Förster resonance energy transfer (FRET) process.


Asunto(s)
Iridio
9.
Inorg Chem ; 61(23): 8797-8805, 2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35652376

RESUMEN

Six homoleptic Ir(III) complexes bearing imidazo[4,5-b]pyrazin-2-ylidene chelates were successfully designed and synthesized. Narrowband blue emission (λmax = 466-485 nm) and broadened green emission (λmax = 518-532 nm) in degassed toluene solution with high photoluminescent quantum yields in the range of 75-81 and 45-48% were observed for f-timpz, t2impz, and t2empz as well as m-timpz, t2impz, and t2empz, respectively. In addition, the tert-butylphenyl cyclometalate is more electron donating than N-phenyl cyclometalate and, hence, all tert-butylphenyl-substituted derivatives, that is, m- and f-t2impz and m- and f-t2empz, give more red-shifted emission in comparison to that of m- and f-timpz. Moreover, solution-processed OLED with f-t2empz (20 wt %) as the dopant gave electrophosphorescence at 474 nm with maximum external quantum efficiency (max. EQE) of 5.1%, while hyper-OLED with assistant sensitizer f-t2empz (10 wt %) and the multi-resonance thermally activated delayed fluorescence emitter BCzBN (0.5 wt %) afforded narrowband emission centered at 485 nm and max. EQE up to 17.4%, confirming the high potential of this class of Ir(III) metal phosphors.

10.
J Sep Sci ; 45(14): 2446-2457, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35503988

RESUMEN

An herbal prescription is usually composed of several herbal medicines. The complex and diverse components bring great challenges to its bioactivity study. To comprehensively analyze the bioactivity of an herbal prescription, a new strategy based on peak-by-peak cutting and knock-out chromatography was proposed. In this strategy, active compounds were screened out via peak-by-peak cutting from an herbal extract, and the influence of a compound on the overall activity of the herbal extract was evaluated by knock-out chromatography. Qiliqiangxin capsule is an herbal prescription composed of 11 herbal medicines for the treatment of chronic heart failure. A total of 71 peaks were collected through peak-by-peak cutting, and each peak was identified by a high-resolution mass spectrum. The bioassay against 1,1-diphenyl-2-picrylhydrazyl showed that two types of compounds namely salvianolic acids and caffeoylquinic acids were potent scavengers. Knock-out chromatography suggested that the removal of one single compound had no obvious influence on the overall activity of the Qiliqiangxin capsule. After all the main peaks in the Qiliqiangxin capsule were knocked out, the remaining part still exhibited a potent activity, indicating high activity stability of the Qiliqiangxin capsule. The proposed strategy is helpful for the comprehensive analysis of the bioactivity of other herbal prescriptions.


Asunto(s)
Medicamentos Herbarios Chinos , Plantas Medicinales , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/análisis , Plantas Medicinales/química , Prescripciones
11.
RSC Adv ; 12(16): 9821-9827, 2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35424938

RESUMEN

Fabricating abundant oxygen vacancies is crucial for non-noble metal oxides to catalyze formaldehyde (HCHO) oxidation at room temperature. Here, a simple one-pot preparation method via solution combustion was found to produce oxygen vacancy-rich Co3O4 catalysts, avoiding delicate defect engineering. The catalyst was evaluated to result in 52% HCHO conversion in a dynamic flow reaction with ∼6 ppm HCHO, which was higher as compared to some other Co3O4 catalysts prepared in three methods of sol-gel, deposition precipitation and thermal decomposition. The optimal catalyst also exhibited high durability with steady HCHO conversion (∼47%) for more than 50 h. The catalyst characterizations revealed that the explosive solution combustion brought out two particular features of Co3O4, namely, the porous network structure with nano-holes and the abundant oxygen vacancies. The latter was demonstrated to increase the reactive oxygen species and to improve the reducibility and the oxygen transport capacity of Co3O4. The two features and the derived properties are beneficial to the activity and durability of Co3O4. The solution combustion method can serve as a simple and feasible way to fabricate abundant oxygen vacancies to provide room-temperature activity of Co3O4 for HCHO elimination at room temperature.

12.
Chemistry ; 28(4): e202103202, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34811829

RESUMEN

Upon fusing the pyrazinyl pyrazole entity in giving pyrazolo[3,4-f]quinoxaline chelate, the corresponding Os(II) based NIR emitter exhibited "invisible" and efficient electroluminescence with a peak maximum at 811 nm. A maximum external quantum efficiency of 0.97 % and a suppressed efficiency roll-off till a current density of 300 mA cm-2 was also exhibited.

13.
Front Cell Dev Biol ; 9: 630279, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33732699

RESUMEN

Autophagy is involved in many physiological processes. Transcription factor EB (TFEB) is a master regulator of autophagy and coordinates the expression of autophagic proteins, lysosomal hydrolases, and lysosomal membrane proteins. Though autophagy has been implicated in several human diseases, little is known regarding TFEB gene expression and regulation in the process. Since dysfunctional autophagy plays critical roles in acute myocardial infarction (AMI), dysregulated TFEB gene expression may be associated with AMI by regulating autophagy. In this study, the TFEB gene promoter was genetically and functionally analyzed in AMI patients (n = 352) and ethnic-matched controls (n = 337). A total of fifteen regulatory variants of the TFEB gene, including eight single-nucleotide polymorphisms (SNPs), were identified in this population. Among these, six regulatory variants [g.41737274T>C (rs533895008), g.41737144A>G, g.41736987C > T (rs760293138), g.41736806C > T (rs748537297), g.41736635T > C (rs975050638), and g.41736544C > T] were only identified in AMI patients. These regulatory variants significantly altered the transcriptional activity of the TFEB gene promoter. Further electrophoretic mobility shift assay revealed that three of the variants evidently affected the binding of transcription factors. Therefore, this study identified novel TFEB gene regulatory variants which affect the gene expression. These TFEB gene regulatory variants may contribute to AMI development as a rare risk factor.

14.
Front Chem ; 8: 528, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32754574

RESUMEN

Gas separation membranes are essential for the capture, storage, and utilization (CSU) of CO2, especially for H2/CO2separation. However, both glassy and rubbery polymer membranes lead a relatively poor selectivity for H2/CO2 separation because the differences in kinetic diameters of these gases are small. The present study establishing the mixed matrix membranes (MMMs) consist of a nano-sized zeolitic imidazolate frameworks (ZIF-8) blended with the polysulfone (PSf) asymmetric membranes. The gas transport properties (H2, CO2, N2, and CH4) of MMMs with a ZIF-8 loading up to 10 wt% were tested and showing significant improvement on permeance of the light gases (e.g., H2 and CO2). Moreover, the depositional polydopamine (PDA) layer further enhanced the ideal H2/CO2 selectivity, and the PDA-modified MMMs approach the Robeson upper bound of H2/CO2 separation membranes. Hence, the PDA post-modification strategy can effectively repair the defects of MMMs and improved the H2/CO2selectivity.

15.
Mol Biol Evol ; 37(12): 3550-3562, 2020 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-32697821

RESUMEN

Genetic and physical mapping of the guppy (Poecilia reticulata) have shown that recombination patterns differ greatly between males and females. Crossover events occur evenly across the chromosomes in females, but in male meiosis they are restricted to the tip furthest from the centromere of each chromosome, creating very high recombination rates per megabase, as in pseudoautosomal regions of mammalian sex chromosomes. We used GC content to indirectly infer recombination patterns on guppy chromosomes, based on evidence that recombination is associated with GC-biased gene conversion, so that genome regions with high recombination rates should be detectable by high GC content. We used intron sequences and third positions of codons to make comparisons between sequences that are matched, as far as possible, and are all probably under weak selection. Almost all guppy chromosomes, including the sex chromosome (LG12), have very high GC values near their assembly ends, suggesting high recombination rates due to strong crossover localization in male meiosis. Our test does not suggest that the guppy XY pair has stronger crossover localization than the autosomes, or than the homologous chromosome in the close relative, the platyfish (Xiphophorus maculatus). We therefore conclude that the guppy XY pair has not recently undergone an evolutionary change to a different recombination pattern, or reduced its crossover rate, but that the guppy evolved Y-linkage due to acquiring a male-determining factor that also conferred the male crossover pattern. We also identify the centromere ends of guppy chromosomes, which were not determined in the genome assembly.


Asunto(s)
Poecilia/genética , Recombinación Genética , Cromosomas Sexuales , Animales , Composición de Base , Centrómero , Femenino , Intrones , Masculino , Mutación Silenciosa , Especificidad de la Especie
16.
Cardiol Res Pract ; 2020: 9898301, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32377431

RESUMEN

Coronary artery disease (CAD) including acute myocardial infarction (AMI) is an inflammatory and metabolic disease mainly caused by atherosclerosis. Dysfunctional autophagy has been associated with abnormal lipid metabolism and inflammation. In previous studies, we have reported altered autophagic activity in AMI patients. As autophagy-related protein 5 (ATG5) is a core protein in autophagy, we speculated that altered ATG5 level may contribute to CAD and AMI development. In this study, the promoter of the ATG5 gene was genetically and functionally investigated in large groups of AMI patients (n = 378) and ethnic-matched healthy controls (n = 386). The results showed that a total of 15 genetic variants including 6 single-nucleotide polymorphisms (SNPs) in the ATG5 gene promoter were found in this study population. A novel deletion variant (g.106326168_70delTCT) and an SNP [g.106325757C > G (rs190825454)] were found in one 66-year-old male patient with non-ST-segment elevated AMI, but in none of controls. In cultured HEK-293 and H9c2 cells, the deletion variant significantly decreased the transcriptional activity of the ATG5 gene promoter (P < 0.01). In contrast, the genetic variants either identified only in controls or found in both AMI patients and controls did not affect the transcriptional activity of the ATG5 gene promoter (P > 0.05). Furthermore, an electrophoretic mobility shift assay showed that the deletion variant evidently affected the binding of a transcription factor. Therefore, the genetic variant identified in AMI may affect the activity of the ATG5 gene promoter and change the ATG5 level, contributing to AMI as a rare risk factor.

17.
ACS Appl Mater Interfaces ; 11(47): 44118-44123, 2019 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-31682102

RESUMEN

Activity and immobilization of catalysts in liquid-phase reactions seem not to coexist. We report here the excellent activity of an MoOx nanoparticle (NP) catalyst for d-glucose epimerization to d-mannose and the electrical immobilization of NPs in a flow reaction. Prior to that, a green and one-pot method to synthesize the MoOx NPs (3.05 nm) via oxidizing metal Mo by hydrogen peroxide was presented. The NPs overwhelmed the reported catalysts including epimerase for d-glucose epimerization, originating from a strong interaction between the NPs and the reactant that was demonstrated by ex situ and in situ characterizations and theoretical calculations. The electrically charged feature of NPs inspired us to find a convenient way to "immobilize" them inside an activated carbon bed, and thereby, a flow reactor was assembled. The continuous epimerization was run under 24 V for 16 days with an almost unchanged activity, and only 3.2% of total Mo was lost.

18.
BMC Cardiovasc Disord ; 19(1): 265, 2019 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-31775637

RESUMEN

BACKGROUND: Coronary artery disease (CAD), including acute myocardial infarction (AMI), is a common complex disease. Although a great number of genetic loci and variants for CAD have been identified, genetic causes and underlying mechanisms remain largely unclear. Epidemiological studies have revealed that CAD incidence is strikingly higher in patients with congenital heart disease than that in normal population. T-box transcription factors play critical roles in embryonic development. In particular, TBX5 as a dosage-sensitive regulator is required for cardiac development and function. Thus, dysregulated TBX5 gene expression may be involved in CAD development. METHODS: TBX5 gene promoter was genetically and functionally analysed in large groups of AMI patients (n = 432) and ethnic-matched healthy controls (n = 448). RESULTS: Six novel heterozygous DNA sequence variants (DSVs) in the TBX5 gene promoter (g.4100A > G, g.4194G > A, g.4260 T > C, g.4367C > A, g.4581A > G and g.5004G > T) were found in AMI patients, but in none of controls. These DSVs significantly changed the activity of TBX5 gene promoter in cultured cells (P < 0.05). Furthermore, three of the DSVs (g.4100A > G, g.4260 T > C and g.4581A > G) evidently modified the binding sites of unknown transcription factors. CONCLUSIONS: The DSVs identified in AMI patients may alter TBX5 gene promoter activity and change TBX5 level, contributing to AMI development as a rare risk factor.


Asunto(s)
Enfermedad de la Arteria Coronaria/genética , Variación Genética , Infarto del Miocardio/genética , Regiones Promotoras Genéticas , Proteínas de Dominio T Box/genética , Animales , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/metabolismo , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Células HEK293 , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/metabolismo , Miocitos Cardíacos/metabolismo , Fenotipo , Ratas , Factores de Riesgo , Proteínas de Dominio T Box/metabolismo
19.
Nano Lett ; 19(9): 6284-6291, 2019 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-31430168

RESUMEN

The fact that metallic nanostructures are an excellent light receiver and transmitter connects the underlying principles of two widely applied optical processes: surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). A comparative study of SERS and SEF can eliminate the typical unknown quantities of the system and reveal important parameters that cannot be accessed by conventional techniques. Here, we use this simultaneous SERS and SEF technique in a monolayer MoSe2 coupled plasmonic nanocavity. After optimizing the spatial and the spectral overlaps between excitonic and plasmonic resonances, the SERS and SEF enhancement factors can exceed 107 and 6000, respectively, at the same time on the same nanocube. The comparison of the SERS and SEF enhancements allows the estimation of the ultrafast total decay rate of the bright exciton in monolayer MoSe2 in the nanocavity down to tens of femtoseconds, which is otherwise hard to realize using time-resolved techniques.

20.
ACS Appl Mater Interfaces ; 11(2): 2197-2204, 2019 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-30565918

RESUMEN

Hybrid single-emitting layer (SEML) white organic light-emitting diodes (WOLEDs) incorporating blue thermally activated delayed fluorescent (TADF) or fluorescent materials and yellow phosphors have been widely utilized for solid-state lighting. Nonetheless, developing appropriate host materials to reduce the large efficiency roll-off at high luminance is still an unsolved issue. Here, two TADF materials denoted as TRZ-CF and TRZ-CzF were synthesized, with electroluminescent emission peaking at 476 and 460 nm, respectively. In particular, TRZ-CF, using 7,7-dimethyl-5,7-dihydroindeno[2,1- b]carbazole (CF) as donor moiety, maintained both highly efficient blue emission (EQEmax = 20.0%) and excellent charge transport abilities. The WOLED utilizing TRZ-CF as host material, doped by 0.8 wt % iridium(III) bis(4-phenylthieno[3,2- c]pyridinato- N, C2') (PO-01), has EQEmax of 20.3%, realizing the lowest roll-off to date of less than 2% at a luminance of 10 000 cd/m2. The efficiency roll-off is alleviated through the reduction the exciton quenching and triplet-triplet annihilation (TTA) within the light-emitting layer, benefited from the TADF effect and bipolar property. The hybrid SEML WOLED exhibits Commission Internationale de L'Eclairage (CIE) coordinates of (0.38, 0.45), providing a practical way to simplify the production complexity and to reduce efficiency roll-off for solid-state lighting.

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