he Cu step bunches formed during the synthesis of graphene by chemical vapor deposition (CVD) have been intensively studied to optimize the electrical and mechanical properties of graphene. For example, it has been reported that the compressive strain due to the mismatch between the thermal expansion coefficients of Cu and graphene tends to be released by forming periodic steps depending on the number of graphene layers. However, the stacking-order dependence of the step bunches in multilayer graphene has not yet been investigated. Here, we show that the twisted bilayer graphene (tBLG) with less compressive strain induces the formation of considerably smaller step bunches compared to the case of AB-stacked bilayer graphene (BLG), as evidenced by atomic force microscopy (AFM) and Raman spectroscopy. It is supposed that interlayer slipping between the weakly coupled tBLG layers weakens mechanical stiffness as well as compressive strain to deform the Cu surface. In addition, we also find that the direction of Cu step bunches depends on the lattice orientation of tBLG. Thus, our findings are expected to provide insights into understanding and improving the electrical and mechanical properties of multilayer CVD graphene for high-performance device applications.

Chromatin configuration is critical for establishing tissue identity and changes substantially during tissue identity transitions. The crucial scientific and agricultural technology of in vitro tissue culture exploits callus formation from diverse tissue explants and tissue regeneration via de novo organogenesis. We investigated the dynamic changes in H3ac and H3K4me3 histone modifications during leaf-to-callus transition in Arabidopsis thaliana. We analyzed changes in the global distribution of H3ac and H3K4me3 during the leaf-to-callus transition, focusing on transcriptionally active regions in calli relative to leaf explants, defined by increased accumulation of both H3ac and H3K4me3. Peptide signaling was particularly activated during callus formation; the peptide hormones RGF3, RGF8, PIP1 and PIPL3 were upregulated, promoting callus proliferation and conferring competence for de novo shoot organogenesis. The corresponding peptide receptors were also implicated in peptide-regulated callus proliferation and regeneration capacity. The effect of peptide hormones in plant regeneration is likely at least partly conserved in crop plants. Our results indicate that chromatin-dependent regulation of peptide hormone production not only stimulates callus proliferation but also establishes pluripotency, improving the overall efficiency of two-step regeneration in plant systems.

Evading recognition of immune cells is a well-known strategy of tumors used for their survival. One of the immune evasion mechanisms is the synthesis of kynurenine (KYN), a metabolite of tryptophan, which suppresses the effector T cells. Therefore, lowering the KYN concentration can be an efficient antitumor therapy by restoring the activity of immune cells. Recently, kynureninase (KYNase), which is an enzyme transforming KYN into anthranilate, was demonstrated to show the potential to decrease KYN concentration and inhibit tumor growth. However, due to the limited bioavailability and instability of proteins in vivo, it has been challenging to maintain the KYNase concentration sufficiently high in the tumor microenvironment (TME). Here, we developed a nanoparticle system loaded with KYNase, which formed a Biodegradable and Implantable Nanoparticle Depot named ‘BIND’ following subcutaneous injection. The BIND sustainably supplied KYNase around the TME while located around the tumor, until it eventually degraded and disappeared. As a result, the BIND system enhanced the proliferation and cytokine production of effector T cells in the TME, followed by tumor growth inhibition and increased mean survival. Finally, we showed that the BIND carrying KYNase significantly synergized with PD-1 blockade in three mouse models of colon cancer, breast cancer, and melanoma.

Ag nanoparticles have garnered significant attention for their excellent plasmonic properties and potential use as plasmonic cavities, primarily because of their intrinsically low ohmic losses and optical properties in the visible range. These are particularly crucial in systems involving quantum dots that absorb light at low wavelengths, where the need for a high threshold energy of interband transitions necessitates the incorporation of Ag nanostructures. However, the synthesis of Ag nanoparticles still encounters challenges in achieving structural uniformity and monodispersity, along with chemical stability, consequentially inducing inconsistent and poorly reliable optical responses. Here, we present a two-step approach for synthesizing highly uniform spherical Ag nanoparticles involving depletion-induced flocculation and Cu(II)-mediated oxidative etching. We found that the selective flocculation of multitwinned Ag nanocrystals significantly enhances the uniformity of the resulting Ag nanostructures, leaving behind only single-crystalline and single-twinned nanostructures. Subsequent oxidative etching, in which cupric ions are directly involved in the reaction, was designed based on Pourbaix diagrams to proceed following thermodynamically favorable states and circumvent the generation of reactive chemical species such as H2O2. This leads to perfectly spherical shapes of final Ag nanoparticles with a synthetic yield of 99.5% and additionally reduces the overall reaction time. Furthermore, we explore the potential applications of these monodisperse Ag nanospheres as uniform plasmonic cavities. The fabricated Ag nanosphere films uniformly enhanced the photoluminescence of InP/ZnSe/ZnS quantum dots, showcasing their capabilities in exhibiting consistent plasmonic responses across a large area.

Ambient temperature affects flowering time in plants, and the MADS-box transcription factor SHORT VEGETATIVE PHASE (SVP) plays a crucial role in the response to changes in ambient temperature. SVP protein stability is regulated by the 26S proteasome pathway and decreases at high ambient temperature, but the details of SVP degradation are unclear. Here, we show that SVP degradation at high ambient temperature is mediated by the CULLIN3-RING E3 ubiquitin ligase (CRL3) complex in Arabidopsis thaliana. We identified a previously uncharacterized protein that interacts with SVP at high ambient temperature and contains a BTB/POZ domain. We named this protein LATE FLOWERING AT HIGH TEMPERATURE 1 (LFH1). Single mutants of LFH1 or CULLIN3A (CUL3A) showed late flowering specifically at 27°C. LFH1 protein levels increased at high ambient temperature. We found that LFH1 interacts with CUL3A in the cytoplasm and is important for SVP-CUL3A complex formation. Mutations in CUL3A and/or LFH1 led to increased SVP protein stability at high ambient temperature, suggesting that the CUL3-LFH1 complex functions in SVP degradation. Screening E2 ubiquitin-conjugating enzymes (UBCs) using RING-BOX PROTEIN 1 (RBX1), a component of the CRL3 complex, as bait identified UBC15. ubc15 mutants also showed late flowering at high ambient temperature. In vitro and in vivo ubiquitination assays using recombinant CUL3A, LFH1, RBX1, and UBC15 showed that SVP is highly ubiquitinated in an ATP-dependent manner. Collectively, these results indicate that the degradation of SVP at high ambient temperature is mediated by a CRL3 complex comprising CUL3A, LFH1, and UBC15.

The direct electrochemical conversion of captured CO2 (capt-eCO2R) into valuable chemicals has recently emerged as a promising carbon capture and utilisation technology that will contribute to achieving net-zero carbon emissions. Conventional electrochemical CO2 (eCO2R) typically uses pure CO2 gas as a reactant; thus, this system requires substantial energy and capital allocation across the entire process, from the initial CO2 capture to the post-CO2 conditioning for product separation. The capt-eCO2R addresses these limitations and presents a compelling economic advantage by integrating the CO2 capture and direct electro-conversion of captured CO2 in the form of carbamate and (bi)carbonate without a CO2 conditioning process. The capt-eCO2R is still in the early stages of development and is not as mature as the conventional eCO2R; thus, several challenges remain to be addressed to improve system performance. This review provides a comprehensive overview of the capt-eCO2R system, including various system configurations, suitable catalysts, and strategies to enhance performance within captured media. The reaction mechanisms depend on the form of captured CO2; therefore, we categorised them according to the type of CO2 absorbent. The outlook, ongoing challenges, and strategies for future development are also presented.

Atomically dispersed active speices on nanomaterials have shown greate promise for various catalytic reactions. In this work, bioinspired bimetallic materials (FeNi-CN) are produced through the mixing of melamine with FeCl2·4H2O and NiCl2·6H2O followed by heat treatment. FeNi-CN exhibits exceptional electrocatalytic activity with an overpotential of 250 mV for oxygen evolution reactions (OERs), which surpasses the well-known IrO2. Additionally, it shows excellent cyclic durability up to 10,000th cycle. The various characterizations reveal the atomically dispersed Fe and Ni atoms across C3N4 networks through coordination to N atoms. Comparative experiments with monometallic samples show that bimetallic FeNi-CN outperforms them. Density functional theory calculations support these findings, indicating that Ni has a higher OER activity than Fe, and the combination of bimetallic Ni and Fe and structural corrugation in FeNi-CN enhances catalytic performance. Ex-situ study supports the electrochemical stability. This work suggests the potential of bimetallic catalysts for electrocatalytic application.

Atomically dispersed metal catalysts or single-atom catalysts have made great strides during the past decade in the catalysis field. While an initial vision of atomically dispersed metal catalysts was to combine the advantages of homogeneous and heterogeneous catalysts, their unexpected potentials continue to be discovered. In this account, we introduce historical backgrounds underpinning the emergence of atomically dispersed metal catalysts. Next, we illustrate some recent examples demonstrating the unusual reactivities of atomically dispersed metal catalysts, which are hard to realize by homogeneous or heterogeneous catalysts. We conclude the account by suggesting the remaining challenges in this exciting field.

Fluorescence resonance energy transfer (FRET) is a powerful spectroscopic method for measuring distances in the 2–8 nm range. Often, conformational changes and molecular interactions are difficult or impossible to synchronize, or too rare or transient to detect using ensemble FRET. Single-molecule FRET (smFRET) opens new opportunities to probe biomolecular conformational changes or interactions that are missing in static snapshots provided by traditional structural biology tools, as well as to measure the kinetics of these dynamics on various timescales and under physiological conditions, including inside cells. Advances in labelling technologies, combining smFRET with optical and magnetic tweezers and Bayesian inference-based and information theory-based analysis tools are revealing rich biomolecular dynamics. We also discuss the challenges and opportunities in integrating dynamics into traditionally static structural biology approaches, extending smFRET into cells and tissues, advancing technical innovations and democratizing the practice of smFRET.

Fe‒S cluster-harboring enzymes, such as carbon monoxide dehydrogenases (CODH), employ sophisticated artificial electron mediators like viologens to serve as potent biocatalysts capable of cleaning-up industrial off-gases at stunning reaction rates. Unraveling the interplay between these enzymes and their associated mediators is essential for improving the efficiency of CODHs. Here we show the electron mediator-interaction site on ChCODHs (Ch, Carboxydothermus hydrogenoformans) using a systematic approach that leverages the viologen-reactive characteristics of superficial aromatic residues. By enhancing mediator-interaction (R57G/N59L) near the D-cluster, the strategically tailored variants exhibit a ten-fold increase in ethyl viologen affinity relative to the wild-type without sacrificing the turn-over rate (kcat). Viologen-complexed structures reveal the pivotal positions of surface phenylalanine residues, serving as external conduits for the D-cluster to/from viologen. One variant (R57G/N59L/A559W) can treat a broad spectrum of waste gases (from steel-process and plastic-gasification) containing O2. Decoding mediator interactions will facilitate the development of industrially high-efficient biocatalysts encompassing gas-utilizing enzymes.