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1.
EMBO J ; 42(5): e111484, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36592032

RESUMO

Plant pathogens compromise crop yields. Plants have evolved robust innate immunity that depends in part on intracellular Nucleotide-binding, Leucine rich-Repeat (NLR) immune receptors that activate defense responses upon detection of pathogen-derived effectors. Most "sensor" NLRs that detect effectors require the activity of "helper" NLRs, but how helper NLRs support sensor NLR function is poorly understood. Many Solanaceae NLRs require NRC (NLR-Required for Cell death) class of helper NLRs. We show here that Rpi-amr3, a sensor NLR from Solanum americanum, detects AVRamr3 from the potato late blight pathogen, Phytophthora infestans, and activates oligomerization of helper NLRs NRC2 and NRC4 into high-molecular-weight resistosomes. In contrast, recognition of P. infestans effector AVRamr1 by another sensor NLR Rpi-amr1 induces formation of only the NRC2 resistosome. The activated NRC2 oligomer becomes enriched in membrane fractions. ATP-binding motifs of both Rpi-amr3 and NRC2 are required for NRC2 resistosome formation, but not for the interaction of Rpi-amr3 with its cognate effector. NRC2 resistosome can be activated by Rpi-amr3 upon detection of AVRamr3 homologs from other Phytophthora species. Mechanistic understanding of NRC resistosome formation will underpin engineering crops with durable disease resistance.


Assuntos
Proteínas NLR , Plantas , Proteínas NLR/metabolismo , Plantas/metabolismo , Resistência à Doença , Domínios Proteicos , Imunidade Vegetal , Doenças das Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
EMBO J ; 42(12): e112514, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36946144

RESUMO

Increasing evidence has shown that light exists in a diverse range of deep-sea environments. We unexpectedly found that blue light is necessary to produce excess zero-valent sulfur (ZVS) in Erythrobacter flavus 21-3, a bacterium that has been recently isolated from a deep-sea cold seep. E. flavus 21-3 is able to convert thiosulfate to ZVS using a novel thiosulfate oxidation pathway comprising a thiosulfate dehydrogenase (TsdA) and a thiosulfohydrolase (SoxB). Using proteomic, bacterial two-hybrid and heterologous expression assays, we found that the light-oxygen-voltage histidine kinase LOV-1477 responds to blue light and activates the diguanylate cyclase DGC-2902 to produce c-di-GMP. Subsequently, the PilZ domain-containing protein mPilZ-1753 binds to c-di-GMP and activates TsdA through direct interaction. Finally, Raman spectroscopy and gene knockout results verified that TsdA and two SoxB homologs cooperate to regulate ZVS production. As ZVS is an energy source for E. flavus 21-3, we propose that deep-sea blue light provides E. flavus 21-3 with a selective advantage in the cold seep, suggesting a previously unappreciated relationship between light-sensing pathways and sulfur metabolism in a deep-sea microorganism.


Assuntos
Proteômica , Tiossulfatos , Tiossulfatos/metabolismo , Bactérias/metabolismo , Oxirredução , Enxofre/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(31): e2319193121, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39052833

RESUMO

Iron-based hexacyanoferrate (Fe-HCF) are promising cathode materials for sodium-ion batteries (SIBs) due to their unique open-channel structure that facilitates fast ion transport and framework stability. However, practical implementation of SIBs has been hindered by low initial Coulombic efficiency (ICE), poor rate performance, and short lifespan. Herein, we report a coordination engineering to synthesize sodium-rich Fe-HCF as cathodes for SIBs through a uniquely designed 10-kg-scale chemical reactor. Our study systematically investigated the relationship between coordination surroundings and the electrochemical behavior. Building on this understanding, the cathode delivered a reversible capacity of 99.3 mAh g-1 at 5 C (1 C = 100 mA g-1), exceptional rate capability (51 mAh g-1 even at 100 C), long lifespan (over 15,000 times at 50 C), and a high ICE of 92.7%. A full cell comprising the Fe-HCF cathode and hard carbon (HC) anode exhibited an impressive cyclic stability with a high-capacity retention rate of 98.3% over 1,000 cycles. Meanwhile, this material can be readily scaled to the practical levels of yield. The findings underscore the potential of Fe-HCF as cathodes for SIBs and highlight the significance of controlling nucleation and morphology through coordination engineering for a sustainable energy storage system.

4.
Proc Natl Acad Sci U S A ; 121(41): e2414037121, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39356673

RESUMO

The ultrafast photochemical reaction mechanism, transient spectra, and transition kinetics of the human blue cone visual pigment have been recorded at room temperature. Ultrafast time-resolved absorption spectroscopy revealed the progressive formation and decay of several metastable photo-intermediates, corresponding to the Batho to Meta-II photo-intermediates previously observed with bovine rhodopsin and human green cone opsin, on the picosecond to millisecond timescales following pulsed excitation. The experimental data reveal several interesting similarities and differences between the photobleaching sequences of bovine rhodopsin, human green cone opsin, and human blue cone opsin. While Meta-II formation kinetics are comparable between bovine rhodopsin and blue cone opsin, the transition kinetics of earlier photo-intermediates and qualitative characteristics of the Meta-I to Meta-II transition are more similar for blue cone opsin and green cone opsin. Additionally, the blue cone photo-intermediate spectra exhibit a high degree of overlap with uniquely small spectral shifts. The observed variation in Meta-II formation kinetics between rod and cone visual pigments is explained based on key structural differences.


Assuntos
Temperatura , Humanos , Cinética , Bovinos , Animais , Opsinas dos Cones/metabolismo , Opsinas dos Cones/química , Rodopsina/química , Rodopsina/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Opsinas de Bastonetes/química , Opsinas de Bastonetes/metabolismo , Pigmentos da Retina/química , Pigmentos da Retina/metabolismo , Análise Espectral/métodos
5.
Proc Natl Acad Sci U S A ; 120(1): e2210561119, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36584294

RESUMO

Brown algae annually convert gigatons of carbon dioxide into carbohydrates, including the complex extracellular matrix polysaccharide fucoidan. Due to its persistence in the environment, fucoidan is potentially a pathway for marine carbon sequestration. Rates of fucoidan secretion by brown algae remain unknown due to the challenge of identifying and quantifying complex polysaccharides in seawater. We adapted the techniques of anion exchange chromatography, enzyme-linked immunosorbent assay, and biocatalytic enzyme-based assay for detection and quantification of fucoidan. We found the brown alga Fucus vesiculosus at the Baltic Sea coast of south-west Finland to secrete 0.3% of their biomass as fucoidan per day. Dissolved fucoidan concentrations in seawater adjacent to algae reached up to 0.48 mg L-1. Fucoidan accumulated during incubations of F. vesiculosus, significantly more in light than in darkness. Maximum estimation by acid hydrolysis indicated fucoidan secretion at a rate of 28 to 40 mg C kg-1 h-1, accounting for 44 to 50% of all exuded dissolved organic carbon. Composed only of carbon, oxygen, hydrogen, and sulfur, fucoidan secretion does not consume nutrients enabling carbon sequestration independent of algal growth. Extrapolated over a year, the algae sequester more carbon into secreted fucoidan than their biomass. The global utility of fucoidan secretion is an alternative pathway for carbon dioxide removal by brown algae without the need to harvest or bury algal biomass.


Assuntos
Dióxido de Carbono , Phaeophyceae , Dióxido de Carbono/metabolismo , Polissacarídeos/metabolismo , Phaeophyceae/metabolismo , Oceanos e Mares
6.
J Biol Chem ; 300(5): 107238, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552736

RESUMO

Light and temperature sensing are important features of many organisms. Light may provide energy but may also be used by non-photosynthetic organisms for orientation in the environment. Recent evidence suggests that plant and fungal phytochrome and plant phototropin serve dual functions as light and temperature sensors. Here we characterized the fungal LOV-domain blue-light receptor LreA of Alternaria alternata and show that it predominantly contains FAD as chromophore. Blue-light illumination induced ROS production followed by protein agglomeration in vitro. In vivo ROS may control LreA activity. LreA acts as a blue-light photoreceptor but also triggers temperature-shift-induced gene expression. Both responses required the conserved amino acid cysteine 421. We therefore propose that temperature mimics the photoresponse, which could be the ancient function of the chromoprotein. Temperature-dependent gene expression control with LreA was distinct from the response with phytochrome suggesting fine-tuned, photoreceptor-specific gene regulation.


Assuntos
Alternaria , Luz Azul , Flavina-Adenina Dinucleotídeo , Proteínas Fúngicas , Fotorreceptores Microbianos , Alternaria/metabolismo , Flavina-Adenina Dinucleotídeo/metabolismo , Flavina-Adenina Dinucleotídeo/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/química , Regulação Fúngica da Expressão Gênica , Fotorreceptores Microbianos/metabolismo , Fotorreceptores Microbianos/química , Fotorreceptores Microbianos/genética , Fitocromo/metabolismo , Fitocromo/química , Fitocromo/genética , Domínios Proteicos , Espécies Reativas de Oxigênio/metabolismo , Temperatura
7.
Plant Physiol ; 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39365781

RESUMO

NONPHOTOTROPIC HYPOCOTYL3 (NPH3) is a key regulator of hypocotyl phototropism under both low- and high-intensity blue light (LBL/HBL), mediating phototropin1 (phot1) and phot2 signaling. NPH3 undergoes dephosphorylation and is released from the plasma membrane (PM) upon blue light irradiation. However, how its phosphorylation status and PM localization mediate phot1 and phot2 signaling in Arabidopsis (Arabidopsis thaliana) remains elusive. In this study, we found that fusing NPH3 with GFP at its C terminus (N3G) impaired its release from the PM, a defect exacerbated by a phosphorylation-deficient mutation, resulting in a dephosphorylated NPH3-GFP (N3AG). Unlike N3G, transgenic lines expressing N3AG exhibited defective hypocotyl phototropism under HBL, which could be rescued by myristoylation at the N-terminus of N3AG (mN3AG), indicating that NPH3 phosphorylation is not essential for HBL-induced phototropic responses when it is artificially anchored at the PM via its N terminus. Furthermore, genetic analysis revealed that N3AG anchored to the PM by its N terminus (as in mN3AG) only rescues phot1-mediated HBL responses, which require RPT2. However, N3AG failed to regulate phot2-mediated HBL signaling, regardless of its PM orientation. Taken together, our results revealed that NPH3 phosphorylation is essential for phot2-mediated hypocotyl phototropism under HBL, but is not required for phot1-mediated HBL signaling when the NPH3 N terminus is PM-anchored.

8.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35165204

RESUMO

Marine coastlines colonized by seagrasses are a net source of methane to the atmosphere. However, methane emissions from these environments are still poorly constrained, and the underlying processes and responsible microorganisms remain largely unknown. Here, we investigated methane turnover in seagrass meadows of Posidonia oceanica in the Mediterranean Sea. The underlying sediments exhibited median net fluxes of methane into the water column of ca. 106 µmol CH4 ⋅ m-2 ⋅ d-1 Our data show that this methane production was sustained by methylated compounds produced by the plant, rather than by fermentation of buried organic carbon. Interestingly, methane production was maintained long after the living plant died off, likely due to the persistence of methylated compounds, such as choline, betaines, and dimethylsulfoniopropionate, in detached plant leaves and rhizomes. We recovered multiple mcrA gene sequences, encoding for methyl-coenzyme M reductase (Mcr), the key methanogenic enzyme, from the seagrass sediments. Most retrieved mcrA gene sequences were affiliated with a clade of divergent Mcr and belonged to the uncultured Candidatus Helarchaeota of the Asgard superphylum, suggesting a possible involvement of these divergent Mcr in methane metabolism. Taken together, our findings identify the mechanisms controlling methane emissions from these important blue carbon ecosystems.


Assuntos
Alismatales/metabolismo , Euryarchaeota/metabolismo , Metano/metabolismo , Aerobiose , Anaerobiose , Euryarchaeota/classificação , Sedimentos Geológicos , Mar Mediterrâneo , Microbiota , Oxirredução , Filogenia , Especificidade da Espécie
9.
Proc Natl Acad Sci U S A ; 119(23): e2117858119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35658072

RESUMO

To increase their chances of survival, prey often behave unpredictably when escaping from predators. However, the response of predators to, and hence the effectiveness of, such tactics is unknown. We programmed interactive prey to flee from an approaching fish predator (the blue acara, Andinoacara pulcher) using real-time computer vision and two-wheeled robots that controlled the prey's movements via magnets. This allowed us to manipulate the prey's initial escape direction and how predictable it was between successive trials with the same individual predator. When repeatedly exposed to predictable prey, the predators adjusted their behavior before the prey even began to escape: prey programmed to escape directly away were approached more rapidly than prey escaping at an acute angle. These faster approach speeds compensated for a longer time needed to capture such prey during the subsequent pursuit phase. By contrast, when attacking unpredictable prey, the predators adopted intermediate approach speeds and were not sensitive to the prey's escape angle but instead showed greater acceleration during the pursuit. Collectively, these behavioral responses resulted in the prey's predictability having no net effect on the time taken to capture prey, suggesting that unpredictable escape behavior may be advantageous to prey in fewer circumstances than originally thought. Rather than minimizing capture times, the predators in our study appear to instead adjust their behavior to maintain an adequate level of performance during prey capture.


Assuntos
Comportamento Predatório , Robótica , Animais , Reação de Fuga , Mamíferos
10.
Proc Natl Acad Sci U S A ; 119(50): e2214545119, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36472961

RESUMO

Aqueous rechargeable ammonium-ion batteries (AIBs) possess the characteristics of safety, low cost, environmental friendliness, and fast diffusion kinetics. However, their energy density is often limited due to the low specific capacity of cathode materials and narrow electrochemical stability windows of electrolytes. Herein, high-performance aqueous AIBs were designed by coupling Fe-substituted manganese-based Prussian blue analog (FeMnHCF) cathodes and highly concentrated NH4CF3SO3 electrolytes. In FeMnHCF, Mn3+/Mn2+-N redox reaction at high potential was introduced, and two metal active redox species of Mn and Fe were achieved. To match such FeMnHCF cathodes, highly concentrated NH4CF3SO3 electrolyte was further developed, where NH4+ ion displays low-solvation structure because of the increased coordination number of CF3SO3- anions. Furthermore, the water molecules are confined by NH4+ and CF3SO3- ions in their solvation sheath, leading to weak interaction between water molecules and thus effectively extending the voltage window of electrolyte. Consequently, the FeMnHCF electrodes present high reversibility during the charge/discharge process. Moreover, owing to a small amount of free water in concentrated electrolyte, the dissolution of FeMnHCF is also inhibited. As a result, the assembled aqueous AIBs exhibit enhanced energy density, excellent rate capability, and stable cycling behavior. This work provides a creative route to construct high-performance aqueous AIBs.

11.
Proc Natl Acad Sci U S A ; 119(36): e2208378119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36037346

RESUMO

The widespread use of antibiotics drives the evolution of antimicrobial-resistant bacteria (ARB), threatening patients and healthcare professionals. Therefore, the development of novel strategies to combat resistance is recognized as a global healthcare priority. The two methods to combat ARB are development of new antibiotics or reduction in existing resistances. Development of novel antibiotics is a laborious and slow-progressing task that is no longer a safe reserve against looming risks. In this research, we suggest a method for reducing resistance to extend the efficacious lifetime of current antibiotics. Antimicrobial photodynamic therapy (aPDT) is used to generate reactive oxygen species (ROS) via the photoactivation of a photosensitizer. ROS then nonspecifically damage cellular components, leading to general impairment and cell death. Here, we test the hypothesis that concurrent treatment of bacteria with antibiotics and aPDT achieves an additive effect in the elimination of ARB. Performing aPDT with the photosensitizer methylene blue in combination with antibiotics chloramphenicol and tetracycline results in significant reductions in resistance for two methicillin-resistant Staphylococcus aureus (MRSA) strains, USA300 and RN4220. Additional resistant S. aureus strain and antibiotic combinations reveal similar results. Taken together, these results suggest that concurrent aPDT consistently decreases S. aureus resistance by improving susceptibility to antibiotic treatment. In turn, this development exhibits an alternative to overcome some of the growing MRSA challenge.


Assuntos
Resistência Microbiana a Medicamentos , Staphylococcus aureus Resistente à Meticilina , Fotoquimioterapia , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos da radiação , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Fármacos Fotossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/farmacologia
12.
Proc Natl Acad Sci U S A ; 119(3)2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35022242

RESUMO

Leaf senescence is a critical process in plants and has a direct impact on many important agronomic traits. Despite decades of research on senescence-altered mutants via forward genetics and functional assessment of senescence-associated genes (SAGs) via reverse genetics, the senescence signal and the molecular mechanism that perceives and transduces the signal remain elusive. Here, using dark-induced senescence (DIS) of Arabidopsis leaf as the experimental system, we show that exogenous copper induces the senescence syndrome and transcriptomic changes in light-grown plants parallel to those in DIS. By profiling the transcriptomes and tracking the subcellular copper distribution, we found that reciprocal regulation of plastocyanin, the thylakoid lumen mobile electron carrier in the Z scheme of photosynthetic electron transport, and SAG14 and plantacyanin (PCY), a pair of interacting small blue copper proteins located on the endomembrane, is a common thread in different leaf senescence scenarios, including DIS. Genetic and molecular experiments confirmed that the PCY-SAG14 module is necessary and sufficient for promoting DIS. We also found that the PCY-SAG14 module is repressed by a conserved microRNA, miR408, which in turn is repressed by phytochrome interacting factor 3/4/5 (PIF3/4/5), the key trio of transcription factors promoting DIS. Together, these findings indicate that intracellular copper redistribution mediated by PCY-SAG14 has a regulatory role in DIS. Further deciphering the copper homeostasis mechanism and its interaction with other senescence-regulating pathways should provide insights into our understanding of the fundamental question of how plants age.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , MicroRNAs/metabolismo , Folhas de Planta/metabolismo , Senescência Vegetal/fisiologia , Arabidopsis/genética , Cobre , Escuridão , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo/metabolismo , Senescência Vegetal/genética , Plantas Geneticamente Modificadas , Fatores de Transcrição/metabolismo , Transcriptoma
13.
Proc Natl Acad Sci U S A ; 119(23): e2121705119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35653565

RESUMO

Marine protected areas (MPAs) are recognized as highly effective tools for marine conservation. They may also play an important role in mitigating climate change. A variety of climate change solutions are rooted in the ocean, centered primarily around "blue carbon" and the capacity of marine life to sequester carbon dioxide (CO2) with some potential to reduce emissions. However, the global potential of these solutions remains misunderstood and untapped. Here, we analyze the potential impact on carbon removal and emissions reduction of adopting six ocean-based solutions in MPAs: coastal wetlands protection, coastal wetlands restoration, macroalgae protection, macroalgae restoration, seafloor protection, and seaweed farming. The carbon removal and avoided emissions achieved by implementing these solutions globally through 2060 were estimated using meta-analysis of existing studies. Applying all six ocean solutions under global implementation scenarios yields total emissions reduction by 2060 of 16.2 ± 1.82 gigatonnes of carbon dioxide equivalent (GtCO2-eq) for the plausible scenario and 24.8 ± 2.46 GtCO2-eq for the ambitious scenario. That equates to around 2% of the total carbon mitigation needed to meet the Paris Agreement goals of limiting global warming to 2 °C by 2050. Around 70% of this reduction is attributable to carbon removal and 30% to avoided emissions. Enhancing MPAs' blue carbon potential could be a key contributor to drawing down carbon and could provide many additional benefits to the marine environment and human society, such as rebuilding biodiversity and sustaining food production. However, more regional-scale studies are needed to inform the best strategies for preserving and enhancing carbon removal in ocean sinks.


Assuntos
Sequestro de Carbono , Carbono , Conservação dos Recursos Naturais , Alga Marinha , Animais , Aquicultura , Clima , Ecossistema , Peixes , Áreas Alagadas
14.
Nano Lett ; 24(1): 479-485, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38147351

RESUMO

Black phosphorus (Black P), a layered semiconductor with a layer-dependent bandgap and high carrier mobility, is a promising candidate for next-generation electronics and optoelectronics. However, the synthesis of large-area, layer-precise, single crystalline Black P films remains a challenge due to their high nucleation energy. Here, we report the molecular beam heteroepitaxy of single crystalline Black P films on a tin monosulfide (SnS) buffer layer grown on Au(100). The layer-by-layer growth mode enables the preparation of monolayer to trilayer films, with band gaps that reflect layer-dependent quantum confinement.

15.
Nano Lett ; 24(37): 11697-11705, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39225479

RESUMO

Osteoarthritis (OA) is a degenerative joint disease characterized by obscure etiology and unsatisfactory therapeutic outcomes, making the development of new efficient therapies urgent. Superfluous reactive oxygen species (ROS) have historically been considered one of the crucial factors inducing the pathological progression of OA. Ultrasmall Prussian blue nanoparticles (USPBNPs), approximately sub-5 nm in size, are developed by regulating the configuration of polyvinylpyrrolidone chains. USPBNPs display an excellent ROS eliminating capacity and catalase-like activity, capable of decomposing hydrogen peroxide (H2O2) into O2. The anti-inflammatory mechanism of USPBNPs can be attributed to repolarizing macrophages from pro-inflammatory M1 to anti-inflammatory M2 phenotype by decreasing the ROS levels accompanied by O2 improvement. Additionally, USPBNPs exhibit an exciting therapeutic efficiency against OA, comparable to that of hydrocortisone in vivo. This study not only develops a new therapeutic agent for OA but also offers an estimable insight into the application of the nanozyme.


Assuntos
Ferrocianetos , Macrófagos , Osteoartrite , Espécies Reativas de Oxigênio , Ferrocianetos/química , Ferrocianetos/farmacologia , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Osteoartrite/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Nanopartículas/química , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Humanos , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Fenótipo , Tamanho da Partícula
16.
Nano Lett ; 24(22): 6601-6609, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38787739

RESUMO

Lead-halide perovskite nanocrystals (NCs) are promising for fabricating deep-blue (<460 nm) light-emitting diodes (LEDs), but their development is plagued by low electroluminescent performance and lead toxicity. Herein, the synthesis of 12 kinds of highly luminescent and eco-friendly deep-blue europium (Eu2+)-doped alkali-metal halides (AX:Eu2+; A = Na+, K+, Rb+, Cs+; X = Cl-, Br-, I-) NCs is reported. Through adjustment of the coordination environment, efficient deep-blue emission from Eu-5d → Eu-4f transitions is realized. The representative CsBr:Eu2+ NCs exhibit a high photoluminescence quantum yield of 91.1% at 441 nm with a color coordinate at (0.158, 0.023) matching with the Rec. 2020 blue specification. Electrically driven deep-blue LEDs from CsBr:Eu2+ NCs are demonstrated, achieving a record external quantum efficiency of 3.15% and half-lifetime of ∼1 h, surpassing the reported metal-halide deep-blue NCs-based LEDs. Importantly, large-area LEDs with an emitting area of 12.25 cm2 are realized with uniform emission, representing a milestone toward commercial display applications.

17.
Nano Lett ; 24(25): 7783-7791, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38869099

RESUMO

The increasing use of low-cost lithium iron phosphate cathodes in low-end electric vehicles has sparked interest in Prussian blue analogues (PBAs) for lithium-ion batteries. A major challenge with iron hexacyanoferrate (FeHCFe), particularly in lithium-ion systems, is its slow kinetics in organic electrolytes and valence state inactivation in aqueous ones. We have addressed these issues by developing a polymeric cathode electrolyte interphase (CEI) layer through a ring-opening reaction of ethylene carbonate triggered by OH- radicals from structural water. This facile approach considerably mitigates the sluggish electrochemical kinetics typically observed in organic electrolytes. As a result, FeHCFe has achieved a specific capacity of 125 mAh g-1 with a stable lifetime over 500 cycles, thanks to the effective activation of Fe low-spin states and the structural integrity of the CEI layers. These advancements shed light on the potential of PBAs to be viable, durable, and efficient cathode materials for commercial use.

18.
Nano Lett ; 24(4): 1268-1276, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38241736

RESUMO

While quasi-two-dimensional (quasi-2D) perovskites have good properties of cascade energy transfer, high exciton binding energy, and high quantum efficiency, which will benefit high-efficiency blue PeLEDs, inefficient domain distribution management and unbalanced carrier transport impede device performance improvement. Herein, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) and methyl 2-aminopyridine-4-carboxylate (MAC) were simultaneously introduced to a blue quasi-2D perovskite film. Relying on the synergistic effect of 2PACz and MAC, it not only modulates the phase distribution inhibiting the n = 2 phase but also greatly improves the electrical property of the quasi-2D perovskite film. As a result, the as-modified blue quasi-2D PeLED demonstrated an external quantum efficiency (EQE) of 17.08% and a luminance of 10142 cd m-2. This study exemplifies the synergistic effect among dual additives and offers a new effective additive strategy modulating phase distribution and building balanced carrier transport, which paves the way for the fabrication of highly efficient blue PeLEDs.

19.
Nano Lett ; 24(19): 5729-5736, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38708832

RESUMO

Quantum-dot light-emitting diodes (QLEDs), a kind of promising optoelectronic device, demonstrate potential superiority in next-generation display technology. Thermal cross-linked hole transport materials (HTMs) have been employed in solution-processed QLEDs due to their excellent thermal stability and solvent resistance, whereas the unbalanced charge injection and high cross-linking temperature of cross-linked HTMs can inhibit the efficiency of QLEDs and limit their application. Herein, a low-temperature cross-linked HTM of 4,4'-bis(3-(((4-vinylbenzyl)oxy)methyl)-9H-carbazol-9-yl)-1,1'-biphenyl (DV-CBP) with a flexible styrene side chain is introduced, which reduces the cross-linking temperature to 150 °C and enhances the hole mobility up to 1.01 × 10-3 cm2 V-1 s-1. More importantly, the maximum external quantum efficiency of 21.35% is successfully obtained on the basis of the DV-CBP as a cross-linked hole transport layer (HTL) for blue QLEDs. The low-temperature cross-linked high-mobility HTL using flexible side chains could be an excellent alternative for future HTL development.

20.
Nano Lett ; 24(17): 5284-5291, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38626333

RESUMO

The performance of blue quantum dot light-emitting diodes (QLEDs) is limited by unbalanced charge injection, resulting from insufficient holes caused by low mobility or significant energy barriers. Here, we introduce an angular-shaped heteroarene based on cyclopentane[b]thiopyran (C8-SS) to modify the hole transport layer poly-N-vinylcarbazole (PVK), in blue QLEDs. C8-SS exhibits high hole mobility and conductivity due to the π···π and S···π interactions. Introducing C8-SS to PVK significantly enhanced hole mobility, increasing it by 2 orders of magnitude from 2.44 × 10-6 to 1.73 × 10-4 cm2 V-1 s-1. Benefiting from high mobility and conductivity, PVK:C8-SS-based QLEDs exhibit a low turn-on voltage (Von) of 3.2 V. More importantly, the optimized QLEDs achieve a high peak power efficiency (PE) of 7.13 lm/W, which is 2.65 times that of the control QLEDs. The as-proposed interface engineering provides a novel and effective strategy for achieving high-performance blue QLEDs in low-energy consumption lighting applications.

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