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1.
Nature ; 613(7942): 66-70, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36600066

RESUMEN

Production of hydrogen fuel from sunlight and water, two of the most abundant natural resources on Earth, offers one of the most promising pathways for carbon neutrality1-3. Some solar hydrogen production approaches, for example, photoelectrochemical water splitting, often require corrosive electrolyte, limiting their performance stability and environmental sustainability1,3. Alternatively, clean hydrogen can be produced directly from sunlight and water by photocatalytic water splitting2,4,5. The solar-to-hydrogen (STH) efficiency of photocatalytic water splitting, however, has remained very low. Here we have developed a strategy to achieve a high STH efficiency of 9.2 per cent using pure water, concentrated solar light and an indium gallium nitride photocatalyst. The success of this strategy originates from the synergistic effects of promoting forward hydrogen-oxygen evolution and inhibiting the reverse hydrogen-oxygen recombination by operating at an optimal reaction temperature (about 70 degrees Celsius), which can be directly achieved by harvesting the previously wasted infrared light in sunlight. Moreover, this temperature-dependent strategy also leads to an STH efficiency of about 7 per cent from widely available tap water and sea water and an STH efficiency of 6.2 per cent in a large-scale photocatalytic water-splitting system with a natural solar light capacity of 257 watts. Our study offers a practical approach to produce hydrogen fuel efficiently from natural solar light and water, overcoming the efficiency bottleneck of solar hydrogen production.

2.
Cell ; 154(5): 1085-1099, 2013 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-23954414

RESUMEN

The molecular mechanism of autophagy and its relationship to other lysosomal degradation pathways remain incompletely understood. Here, we identified a previously uncharacterized mammalian-specific protein, Beclin 2, which, like Beclin 1, functions in autophagy and interacts with class III PI3K complex components and Bcl-2. However, Beclin 2, but not Beclin 1, functions in an additional lysosomal degradation pathway. Beclin 2 is required for ligand-induced endolysosomal degradation of several G protein-coupled receptors (GPCRs) through its interaction with GASP1. Beclin 2 homozygous knockout mice have decreased embryonic viability, and heterozygous knockout mice have defective autophagy, increased levels of brain cannabinoid 1 receptor, elevated food intake, and obesity and insulin resistance. Our findings identify Beclin 2 as a converging regulator of autophagy and GPCR turnover and highlight the functional and mechanistic diversity of Beclin family members in autophagy, endolysosomal trafficking, and metabolism.


Asunto(s)
Autofagia , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis/química , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Beclina-1 , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Lisosomas/metabolismo , Masculino , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Datos de Secuencia Molecular , Obesidad/metabolismo , Alineación de Secuencia
3.
Nature ; 612(7939): 259-265, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36443603

RESUMEN

The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles highly sought after yet challenging in regard to (meta)materials1-3. Here we show that tetrahedral gold nanoparticles can transform from a perovskite-like, low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. Whereas corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices show strong chiroptical activity as identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of substrate-supported chiral superlattices facilitate the manufacture of metastructured coatings with unusual optical, mechanical and electronic characteristics.


Asunto(s)
Oro , Nanopartículas del Metal , Electrónica , Física
4.
Proc Natl Acad Sci U S A ; 121(23): e2322359121, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38805286

RESUMEN

Rearranged during transfection (RET) rearrangement oncoprotein-mediated Ras/MAPK signaling cascade is constitutively activated in cancers. Here, we demonstrate a unique signal niche. The niche is a ternary complex based on the chimeric RET liquid-liquid phase separation. The complex comprises the rearranged kinase (RET fusion); the adaptor (GRB2), and the effector (SHC1). Together, they orchestrate the Ras/MAPK signal cascade, which is dependent on tyrosine kinase. CCDC6-RET fusion undergoes LLPS requiring its kinase domain and its fusion partner. The CCDC6-RET fusion LLPS promotes the autophosphorylation of RET fusion, with enhanced kinase activity, which is necessary for the formation of the signaling niche. Within the signal niche, the interactions among the constituent components are reinforced, and the signal transduction efficiency is amplified. The specific RET fusion-related signal niche elucidates the mechanism of the constitutive activation of the Ras/MAPK signaling pathway. Beyond just focusing on RET fusion itself, exploration of the ternary complex potentially unveils a promising avenue for devising therapeutic strategies aimed at treating RET fusion-driven diseases.


Asunto(s)
Proteína Adaptadora GRB2 , Sistema de Señalización de MAP Quinasas , Proteínas de Fusión Oncogénica , Proteínas Proto-Oncogénicas c-ret , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Proteínas ras , Humanos , Proteína Adaptadora GRB2/metabolismo , Proteína Adaptadora GRB2/genética , Células HEK293 , Proteínas de Fusión Oncogénica/metabolismo , Proteínas de Fusión Oncogénica/genética , Fosforilación , Proteínas Proto-Oncogénicas c-ret/metabolismo , Proteínas Proto-Oncogénicas c-ret/genética , Proteínas ras/metabolismo , Proteínas ras/genética , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/metabolismo , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/genética
5.
Blood ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39046762

RESUMEN

Atypical acute promyelocytic leukemia (aAPL) presents a complex landscape of retinoic acid receptor (RAR) fusion genes beyond the well-known PML::RARA fusion. Among these, 31 individually rare RARA and RARG fusion genes have been documented, often reported in the canonical X::RAR bipartite fusion form. Intriguingly, some artificially mimicked bipartite X::RAR fusions respond well to all-trans retinoic acid (ATRA) in vitro, contrasting with the ATRA resistance observed in patients. To unravel the underlying mechanisms, we conducted a comprehensive molecular investigation into the fusion transcripts in 27 RARA fusion gene-positive aAPL (RARA-aAPL) and 21 RARG-aAPL cases. Our analysis revealed an unexpected novel form of X::RAR::X or X::RAR::Y-type tripartite fusions in certain RARA- and all RARG-aAPL cases, with shared features and notable differences between these two disease subgroups. In RARA-aAPL cases, the occurrence of RARA 3' splices was associated with their 5' fusion partner genes, mapping across the coding region of helix 11_12 (H11_12) within the ligand-binding domain (LBD), resulting in LBD-H12 or H11_12 truncation. In RARG-aAPL cases, RARG 3' splices were consistently localized to the terminus of exon 9, leading to LBD-H11_12 truncation. Significant differences were also observed between RARA and RARG 5' splice patterns. Our analysis also revealed extensive involvement of transposable elements in constructing RARA and RARG 3' fusions, suggesting transposition mechanisms for fusion gene ontogeny. Both protein structural analysis and experimental results highlighted the pivotal role of LBD-H11_12/H12 truncation in driving ATRA unresponsiveness and leukemogenesis in tripartite fusion-positive aAPL, through a protein allosteric dysfunction mechanism.

6.
Proc Natl Acad Sci U S A ; 120(44): e2303473120, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37874860

RESUMEN

Interface engineering in heterostructures at the atomic scale has been a central research focus of nanoscale and quantum material science. Despite its paramount importance, the achievement of atomically ordered heterointerfaces has been severely limited by the strong diffusive feature of interfacial atoms in heterostructures. In this work, we first report a strong dependence of interfacial diffusion on the surface polarity. Near-perfect quantum interfaces can be readily synthesized on the semipolar plane instead of the conventional c-plane of GaN/AlN heterostructures. The chemical bonding configurations on the semipolar plane can significantly suppress the cation substitution process as evidenced by first-principles calculations, which leads to an atomically sharp interface. Moreover, the surface polarity of GaN/AlN can be readily controlled by varying the strain relaxation process in core-shell nanostructures. The obtained extremely confined, interdiffusion-free ultrathin GaN quantum wells exhibit a high internal quantum efficiency of ~75%. Deep ultraviolet light-emitting diodes are fabricated utilizing a scalable and robust method and the electroluminescence emission is nearly free of the quantum-confined Stark effect, which is significant for ultrastable device operation. The presented work shows a vital path for achieving atomically ordered quantum heterostructures for III-nitrides as well as other polar materials such as III-arsenides, perovskites, etc.

7.
Proc Natl Acad Sci U S A ; 119(40): e2208051119, 2022 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-36161940

RESUMEN

Periodic networks on the verge of mechanical instability, called Maxwell lattices, are known to exhibit zero-frequency modes localized to their boundaries. Topologically polarized Maxwell lattices, in particular, focus these zero modes to one of their boundaries in a manner that is protected against disorder by the reciprocal-space topology of the lattice's band structure. Here, we introduce a class of mechanical bilayers as a model system for designing topologically protected edge modes that couple in-plane dilational and shearing modes to out-of-plane flexural modes, a paradigm that we refer to as "omnimodal polarization." While these structures exhibit a high-dimensional design space that makes it difficult to predict the topological polarization of generic geometries, we are able to identify a family of mirror-symmetric bilayers that inherit the in-plane modal localization of their constitutive monolayers, whose topological polarization can be determined analytically. Importantly, the coupling between the layers results in the emergence of omnimodal polarization, whereby in-plane and out-of-plane edge modes localize on the same edge. We demonstrate these theoretical results by fabricating a mirror-symmetric, topologically polarized kagome bilayer consisting of a network of elastic beams via additive manufacturing and confirm this finite-frequency polarization via finite element analysis and laser-vibrometry experiments.


Asunto(s)
Luz , Modelos Teóricos , Análisis de Elementos Finitos , Impresión Tridimensional , Refracción Ocular
8.
Proc Natl Acad Sci U S A ; 119(52): e2211725119, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36534795

RESUMEN

Concepts from quantum topological states of matter have been extensively utilized in the past decade to create mechanical metamaterials with topologically protected features, such as one-way edge states and topologically polarized elasticity. Maxwell lattices represent a class of topological mechanical metamaterials that exhibit distinct robust mechanical properties at edges/interfaces when they are topologically polarized. Realizing topological phase transitions in these materials would enable on-and-off switching of these edge states, opening opportunities to program mechanical response and wave propagation. However, such transitions are extremely challenging to experimentally control in Maxwell topological metamaterials due to mechanical and geometric constraints. Here we create a Maxwell lattice with bistable units to implement synchronized transitions between topological states and demonstrate dramatically different stiffnesses as the lattice transforms between topological phases both theoretically and experimentally. By combining multistability with topological phase transitions, this metamaterial not only exhibits topologically protected mechanical properties that swiftly and reversibly change, but also offers a rich design space for innovating mechanical computing architectures and reprogrammable neuromorphic metamaterials. Moreover, we design and fabricate a topological Maxwell lattice using multimaterial 3D printing and demonstrate the potential for miniaturization via additive manufacturing. These design principles are applicable to transformable topological metamaterials for a variety of tasks such as switchable energy absorption, impact mitigation, wave tailoring, neuromorphic metamaterials, and controlled morphing systems.


Asunto(s)
Comercio , Impresión Tridimensional , Elasticidad , Miniaturización , Transición de Fase
9.
Proc Natl Acad Sci U S A ; 119(21): e2119765119, 2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35594392

RESUMEN

SignificanceQuantum coherence has a fundamentally different origin for nonidentical and identical particles since for the latter a unique contribution exists due to indistinguishability. Here we experimentally show how to exploit, in a controllable fashion, the contribution to quantum coherence stemming from spatial indistinguishability. Our experiment also directly proves, on the same footing, the different role of particle statistics (bosons or fermions) in supplying coherence-enabled advantage for quantum metrology. Ultimately, our results provide insights toward viable quantum-enhanced technologies based on tunable indistinguishability of identical building blocks.

10.
Am J Respir Cell Mol Biol ; 70(5): 364-378, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38300138

RESUMEN

Various infections trigger a storm of proinflammatory cytokines in which IL-6 acts as a major contributor and leads to diffuse alveolar damage in patients. However, the metabolic regulatory mechanisms of IL-6 in lung injury remain unclear. Polyriboinosinic-polyribocytidylic acid [poly(I:C)] activates pattern recognition receptors involved in viral sensing and is widely used in alternative animal models of RNA virus-infected lung injury. In this study, intratracheal instillation of poly(I:C) with or without an IL-6-neutralizing antibody model was combined with metabonomics, transcriptomics, and so forth to explore the underlying molecular mechanisms of IL-6-exacerbated lung injury. We found that poly(I:C) increased the IL-6 concentration, and the upregulated IL-6 further induced lung ferroptosis, especially in alveolar epithelial type II cells. Meanwhile, lung regeneration was impaired. Mechanistically, metabolomic analysis showed that poly(I:C) significantly decreased glycolytic metabolites and increased bile acid intermediate metabolites that inhibited the bile acid nuclear receptor farnesoid X receptor (FXR), which could be reversed by IL-6-neutralizing antibody. In the ferroptosis microenvironment, IL-6 receptor monoclonal antibody tocilizumab increased FXR expression and subsequently increased the Yes-associated protein (YAP) concentration by enhancing PKM2 in A549 cells. FXR agonist GW4064 and liquiritin, a potential natural herbal ingredient as an FXR regulator, significantly attenuated lung tissue inflammation and ferroptosis while promoting pulmonary regeneration. Together, the findings of the present study provide the evidence that IL-6 promotes ferroptosis and impairs regeneration of alveolar epithelial type II cells during poly(I:C)-induced murine lung injury by regulating the FXR-PKM2-YAP axis. Targeting FXR represents a promising therapeutic strategy for IL-6-associated inflammatory lung injury.


Asunto(s)
Ferroptosis , Interleucina-6 , Pulmón , Poli I-C , Receptores Citoplasmáticos y Nucleares , Ferroptosis/efectos de los fármacos , Animales , Poli I-C/farmacología , Interleucina-6/metabolismo , Ratones , Receptores Citoplasmáticos y Nucleares/metabolismo , Pulmón/patología , Pulmón/metabolismo , Pulmón/efectos de los fármacos , Ratones Endogámicos C57BL , Masculino , Lesión Pulmonar/metabolismo , Lesión Pulmonar/patología , Lesión Pulmonar/tratamiento farmacológico , Humanos , Transducción de Señal/efectos de los fármacos
11.
J Lipid Res ; 65(9): 100633, 2024 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-39182608

RESUMEN

Dynamin-related protein 1 (DRP1) plays crucial roles in mitochondrial and peroxisome fission. However, the mechanisms underlying the functional regulation of DRP1 in adipose tissue during obesity remain unclear. To elucidate the metabolic and pathological significance of diminished DRP1 in obese adipose tissue, we utilized adipose tissue-specific DRP1 KO mice challenged with a high-fat diet. We observed significant metabolic dysregulations in the KO mice. Mechanistically, DRP1 exerts multifaceted functions in mitochondrial dynamics and endoplasmic reticulum (ER)-lipid droplet crosstalk in normal mice. Loss of function of DRP1 resulted in abnormally giant mitochondrial shapes, distorted mitochondrial membrane structure, and disrupted cristae architecture. Meanwhile, DRP1 deficiency induced the retention of nascent lipid droplets in ER, leading to perturbed overall lipid dynamics in the KO mice. Collectively, dysregulation of the dynamics of mitochondria, ER, and lipid droplets contributes to whole-body metabolic disorders, as evidenced by perturbations in energy metabolites. Our findings demonstrate that DRP1 plays diverse and critical roles in regulating energy metabolism within adipose tissue during the progression of obesity.

12.
J Cell Physiol ; : e31437, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300779

RESUMEN

Enamel protects teeth from external irritation and its formation involves sequential differentiation of ameloblasts, a dental epithelial cell. Keratinocyte differentiation factor 1 (KDF1) is important in the development of epithelial tissues and organs. However, the specific role of KDF1 in enamel formation and corresponding regulatory mechanisms are unclear. This study demonstrated that KDF1 was persistently expressed in all stages of ameloblast differentiation, through RNAscope in situ hybridization. KDF1 expression in the mouse ameloblast cell line LS8 was demonstrated via immunofluorescence assay. KDF1 was knocked out in LS8 cells using the CRISPR/Cas-9 system or overexpressed in LS8 cells through lentiviral infection. In vitro ameloblast differentiation induction, quantitative reverse transcription PCR, western blot analysis, and alkaline phosphatase (ALP) assay indicated that knockout or overexpression of KDF1 in LS8 cells decreased or increased the mRNA and protein levels of several key amelogenesis markers, as well as ALP activity. Furthermore, liquid chromatography-mass spectrometry and co-immunoprecipitation analyses revealed that KDF1 can interact with the IKK complex, thereby inhibiting the NF-κB pathway. Suppressing NF-κB activity partially recovered the decreased ameloblast differentiation in LS8 cells induced by KDF1-knockout. This study demonstrated that KDF1 can promote ameloblast differentiation of LS8 cells by inhibiting the IKK/IκB/NF-κB axis, and is a potential target for functional enamel regeneration.

13.
BMC Genomics ; 25(1): 876, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39294575

RESUMEN

BACKGROUND: Begomoviruses are major constraint in the production of many crops. Upon infection, begomoviruses may substantially modulate plant biological processes. While how monopartite begomoviruses interact with their plant hosts has been investigated extensively, bipartite begomoviruses-plant interactions are understudied. Moreover, as one of the major groups of hosts, cucurbitaceous plants have been seldom examined in the interaction with begomoviruses. RESULTS: We profiled the zucchini transcriptomic changes induced by a bipartite begomovirus squash leaf curl China virus (SLCCNV). We identified 2275 differentially-expressed genes (DEGs), of which 1310 were upregulated and 965 were downregulated. KEGG enrichment analysis of the DEGs revealed that many pathways related to primary and secondary metabolisms were enriched. qRT-PCR verified the transcriptional changes of twelve selected DEGs induced by SLCCNV infection. Close examination revealed that the expression levels of all the DEGs of the pathway Photosynthesis were downregulated upon SLCCNV infection. Most DEGs in the pathway Plant-pathogen interaction were upregulated, including some positive regulators of plant defenses. Moreover, the majority of DEGs in the MAPK signaling pathway-plant were upregulated. CONCLUSION: Our findings indicates that SLCCNV actively interact with its cucurbitaceous plant host by suppressing the conversion of light energy to chemical energy and inducing immune responses. Our study not only provides new insights into the interactions between begomoviruses and host plants, but also adds to our knowledge on virus-plant interactions in general.


Asunto(s)
Begomovirus , Perfilación de la Expresión Génica , Interacciones Huésped-Patógeno , Enfermedades de las Plantas , Begomovirus/genética , Interacciones Huésped-Patógeno/genética , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/genética , Transcriptoma , Regulación de la Expresión Génica de las Plantas , Cucurbita/virología , Cucurbita/genética
14.
Rep Prog Phys ; 87(10)2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39222655

RESUMEN

Symmetry-breaking orders can not only compete with each other, but also be intertwined, and the intertwined topological and symmetry-breaking orders make the situation more intriguing. This work examines the archetypal correlated flat band model on a checkerboard lattice at fillingν=2/3and we find that the unique interplay between smectic charge order and topological order gives rise to two novel quantum states. As the interaction strength increases, the system first transitions from a Fermi liquid (FL) into FQAH smectic (FQAHS) state, where the topological order coexists cooperatively with smectic charge order with enlarged ground-state degeneracy and interestingly, the Hall conductivity isσxy=ν=2/3, different from the band-folding or doping scenarios. Further increasing the interaction strength, the system undergoes another quantum phase transition and evolves into a polar smectic metal (PSM) state. This emergent PSM is an anisotropic non-Fermi liquid, whose interstripe tunneling is irrelevant while it is metallic inside each stripe. Different from the FQAHS and conventional smectic orders, this PSM spontaneously breaks the two-fold rotational symmetry, resulting in a nonzero electric dipole moment and ferroelectric order. In addition to the exotic ground states, large-scale numerical simulations are also used to study low-energy excitations and thermodynamic characteristics. We find that the onset temperature of the incompressible FQAHS state, which also coincides with the onset of non-polar smectic order, is dictated by the magneto-roton modes. Above this onset temperature, the PSM state exists at an intermediate-temperature regime. Although theT = 0 quantum phase transition between PSM and FQAHS is first order, the thermal FQAHS-PSM transition could be continuous. We expect the features of the exotic states and thermal phase transitions could be accessed in future experiments.

15.
Br J Haematol ; 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39191510

RESUMEN

Wilms' tumour 1 (WT1) can function as an oncogene or a tumour suppressor. Our previous clinical cohort studies showed that low WT1 expression at diagnosis independently predicted poor outcomes in acute myeloid leukaemia (AML) with RUNX1::RUNX1T1, whereas it had an opposite role in AML with non-favourable cytogenetic risk (RUNX1::RUNX1T1-deficient). The molecular mechanism by which RUNX1::RUNX1T1 affects the prognostic significance of WT1 in AML remains unknown. In the present study, first we validated the prognostic significance of WT1 expression in AML. Then by using the established transfected cell lines and xenograft tumour model, we found that WT1 suppresses proliferation and enhances effect of cytarabine in RUNX1::RUNX1T1(+) AML but has opposite functions in AML cells without RUNX1::RUNX1T1. Furthermore, as a transcription factor, WT1 physically interacts with RUNX1::RUNX1T1 and acts as a co-factor together with RUNX1::RUNX1T1 to activate the expression of its target gene DUSP6 to dampen extracellular signal-regulated kinase (ERK) activity. When RUNX1::RUNX1T1-deficient, WT1 can activate the mitogen-activated extracellular signal-regulated kinase/ERK axis but not through targeting DUSP6. These results provide a mechanism by which WT1 together with RUNX1::RUNX1T1 suppresses cell proliferation through WT1/DUSP6/ERK axis in AML. The current study provides an explanation for the controversial prognostic significance of WT1 expression in AML patients.

16.
Small ; : e2400784, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38837286

RESUMEN

Marine biofouling is a complex and dynamic process that significantly increases the carbon emissions from the maritime industry by increasing drag losses. However, there are no existing non-toxic marine paints that can achieve both effective fouling reduction and efficient fouling release. Inspired by antifouling strategies in nature, herein, a superoleophobic zwitterionic nanowire coating with a nanostructured hydration layer is introduced, which exhibits simultaneous fouling reduction and release performance. The zwitterionic nanowires demonstrate >25% improvement in fouling reduction compared to state-of-the-art antifouling nanostructures, and four times higher fouling-release compared to conventional zwitterionic coatings. Fouling release is successfully achieved under a wall shear force that is four orders of magnitude lower than regular water jet cleaning. The mechanism of this simultaneous fouling reduction and release behavior is explored, and it is found that a combination of 1) a mechanical biocidal effect from the nanowire geometry, and 2) low interfacial adhesion resulting from the nanostructured hydration layer, are the major contributing factors. These findings provide insights into the design of nanostructured coatings with simultaneous fouling reduction and release. The newly established synthesis procedure for the zwitterionic nanowires opens new pathways for implementation as antifouling coatings in the maritime industry and biomedical devices.

17.
Small ; : e2405674, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39225385

RESUMEN

Si provides an effective approach to achieving high-energy batteries owing to its high energy density and abundance. However, the poor stability of Si requires buffering with graphite particles when used as anodes. Currently, commercial lithium-ion batteries with Si/graphite composite anodes can provide a high energy density and are expected to replace traditional graphite-based batteries. The different lithium storage properties of Si and graphite lead to different degrees of lithiation and chemical environments for this composite anode, which significantly affects the performance of batteries. Herein, the interplay between Si and graphite in mechanically mixed Si/graphite composite anodes is emphasized, which alters the lithiation sequence of the active materials and thus the cycling performance of the battery. Furthermore, performance optimization can be achieved by changing the intrinsic properties of the active materials and external operating conditions, which are summarized and explained in detail. The investigation of the interplay based on Si/graphite composite anodes lays the foundation for developing long-life and high-energy batteries. The abovementioned experimental methods provide logical guidance for future research on composite electrodes with multiple active materials.

18.
Small ; 20(2): e2304210, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37626458

RESUMEN

Due to their high designability, unique geometric and electronic structures, and surface coordination chemistry, atomically precise metal nanoclusters are an emerging class of functional nanomaterials at the forefront of materials research. However, the current research on metal nanoclusters is mainly fundamental, and their practical applications are still uncharted. The surface binding properties and redox activity of Au24 Pt(PET)18 (PET: phenylethanethiolate, SCH2 CH2 Ph) nanoclusters are herein harnessed as an high-efficiency electrocatalyst for the anchoring and rapid conversion of lithium polysulfides in lithium-sulfur batteries (LSBs). Au24 Pt(PET)18 @G composites are prepared by using the large specific surface area, high porosity, and conductive network of graphene (G) for the construction of battery separator that can inhibit polysulfide shuttle and accelerate electrochemical kinetics. Resultantly, the LSB using a Au24 Pt(PET)18 @G-based separator presents a high reversible specific capacity of 1535.4 mA h g-1 for the first cycle at 0.2 A g-1 and a rate capability of 887 mA h g-1 at 5 A g-1 . After 1000 cycles at 5 A g-1 , the capacity is 558.5 mA h g-1 . This study is a significant step toward the application of metal nanoclusters as optimal electrocatalysts for LSBs and other sustainable energy storage systems.

19.
Small ; 20(24): e2311180, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38174602

RESUMEN

The practical application of the room-temperature sodium-sulfur (RT Na-S) batteries is currently limited by low reversible capacity and serious capacity decay due to the sluggish reaction kinetics and shuttle effect. It is necessary to design a suitable sulfur host integrated with electrocatalysts to realize effective chemisorption and catalysis of sodium polysulfides (NaPSs). Herein, under the guidance of theoretical calculation, the Mott-Schottky heterojunction with a built-in electric field composed of iron (Fe) and iron disulfide (FeS2) components anchored on a porous carbon matrix (Fe/FeS2-PC) is designed and prepared. The enhanced chemisorption effect of Fe, the fast electrocatalytic effect of FeS2, and the fast transfer effect of the built-in electric field within the Fe/FeS2 heterojunction in the cathode of RT Na-S batteries work together to effectively improve the electrochemical performance. As a result, the Fe/FeS2-PC@S cathode exhibits high reversible capacity (815 mAh g-1 after 150 cycles at 0.2 A g-1) and excellent stability (516 mAh g-1 after 600 cycles at 5 A g-1, with only 0.07% decay per cycle). The design of the Fe/FeS2 heterojunction electrocatalyst provides a new strategy for the development of highly stable RT Na-S batteries.

20.
Small ; 20(24): e2309559, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38243884

RESUMEN

Hopper-shaped microcrystals, an unusual type of crystal with a large specific surface area, are promising for use in catalysis, drug delivery, and gas sensors. In contrast to well-studied inorganic hopper-shaped crystals, organic phosphorescent concave hopper-shaped microstructures are rarely reported. This study reports the synthesis of two types of organic stepped indented hopper-shaped microstructures with efficient room temperature phosphorescence (RTP) using a liquid phase self-assembly strategy. The formation mechanism is attributed to the interfacial instability induced by the concentration gradient and selective etching. Compared with flat microstructures, the stepped indented hopper-like RTP microstructures exhibit high sensitivity to oxygen. This work also demonstrates that packing the photochromic material into the concave hopper "vessel" effectively controls the switch of phosphorescence from energy transfer, expanding the potential applications of phosphorescent materials.

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