Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and ...good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag‐N2C2/CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag‐N2C2 configuration have been identified by aberration‐correction high‐angle‐annular‐dark‐field scanning transmission electron microscopy (AC‐HAADF‐STEM) and extended X‐ray absorption. Experiments and DFT calculations further verify that Ag‐N2C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag‐N2C2/CN catalyst exhibits much better H2 evolution activity than the N‐coordinated Ag single atom in CN (Ag‐N4/CN), and is even superior to the Pt nanoparticle‐loaded CN (PtNP/CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.
A new Ag single atom in carbon nitride (Ag‐N2C2/CN) photocatalyst with Ag‐N2C2 configuration is developed. It affords fast charge transfer, high Ag loading, and good stability. Noteworthily, the Ag‐N2C2/CN exhibits much better hydrogen evolution activity than Ag‐N4/CN, and even superior to the platinum‐loaded CN.
SUMMARY
Drought stress induces anthocyanin biosynthesis in many plant species, but the underlying molecular mechanism remains unclear. Ethylene response factors (ERFs) play key roles in plant growth ...and various stress responses, including affecting anthocyanin biosynthesis. Here, we characterized an ERF protein, MdERF38, which is involved in drought stress‐induced anthocyanin biosynthesis. Biochemical and molecular analyses showed that MdERF38 interacted with MdMYB1, a positive modulator of anthocyanin biosynthesis, and facilitated the binding of MdMYB1 to its target genes. Therefore, MdERF38 promoted anthocyanin biosynthesis in response to drought stress. Furthermore, we found that MdBT2, a negative modulator of anthocyanin biosynthesis, decreased MdERF38‐promoted anthocyanin biosynthesis by accelerating the degradation of the MdERF38 protein. In summary, our data provide a mechanism for drought stress‐induced anthocyanin biosynthesis that involves dynamic modulation of MdERF38 at both transcriptional and post‐translational levels.
Significance Statement
MdERF38 promotes anthocyanin biosynthesis by interacting with MdMYB1 and enhancing the binding of MdMYB1 to its target genes in response to drought stress. MdBT2 decreases drought‐induced anthocyanin accumulation by accelerating the degradation of MdERF38.
Photoreactive olefinic species are incorporated into a metal–organic framework (MOF), Zn(bdc)(3‐F‐spy) (1). Single crystals of 1 are shown to undergo three types of photomechanical macroscopic ...deformation upon illumination by UV light. To demonstrate the practical potential of this system, the inclusion of 1 in a PVA (polyvinyl alcohol) composite membrane, by exploiting hydrogen‐bonding interactions, is presented. Using this composite membrane, the amplification of mechanical stress to achieve macroscopic actuation behavior is demonstrated. These results pave the way for the generation of MOF‐based soft photoactuators that produce clearly defined mechanical responses upon irradiation with light. Such systems are anticipated to have considerable potential in photomechanical energy harvesting and conversion systems.
A self‐assembly strategy for the fabrication of a hierarchical photoactuator system in which a photoresponsive moiety is incorporated into a MOF crystal. A photoactuation system was successfully fabricated that involves a MOF‐PVA composite membrane, which exhibits a macroscopic response upon exposure to UV light irradiation.
Summary
The plant hormone jasmonic acid (JA) is involved in the cold stress response, and the inducer of CBF expression 1 (ICE1)‐ C‐repeat binding factor (CBF) regulatory cascade plays a key role in ...the regulation of cold stress tolerance. In this study, we showed that a novel B‐box (BBX) protein MdBBX37 positively regulates JA‐mediated cold‐stress resistance in apple.
We found that MdBBX37 bound to the MdCBF1 and MdCBF4 promoters to activate their transcription, and also interacted with MdICE1 to enhance the transcriptional activity of MdICE1 on MdCBF1, thus promoting its cold tolerance.
Two JA signaling repressors, MdJAZ1 and MdJAZ2 (JAZ, JAZMONATE ZIM‐DOMAIN), interacted with MdBBX37 to repress the transcriptional activity of MdBBX37 on MdCBF1 and MdCBF4, and also interfered with the interaction between MdBBX37 and MdICE1, thus negatively regulating JA‐mediated cold tolerance. E3 ligase MdMIEL1 (MIEL1, MYB30‐Interacting E3 Ligase1) reduced MdBBX37‐improved cold resistance by mediating ubiquitination and degradation of the MdBBX37 protein.
The data reveal that MIEL1 and JAZ proteins co‐regulate JA‐mediated cold stress tolerance through the BBX37‐ICE1‐CBF module in apple. These results will aid further examination of the post‐translational modification of BBX proteins and the regulatory mechanism of JA‐mediated cold stress tolerance.
Development of special organic materials that are able to absorb light energy in the second near-infrared window (NIR-II) is significantly important for treating deep-tissue-buried diseases or ...supplying power to implantable electronic devices. Herein, a narrow bandgap donor–acceptor (D-A) conjugated polymer with thiophene-fused benzodifurandione-based oligo(p-phenylenevinylene) (TBDOPV) as acceptor part and 2,2′-bithiophene (DT) as donor part was developed and exploited as a photothermal conversion material with high extinction coefficient and robust photostability in the NIR-II window. According to transient absorption analysis results, the photothermal conversion ability of this polymer is attributed to the fast internal conversion (IC) process. The high photothermal conversion efficiency makes this polymer a promising NIR-II adsorbing antenna to remotely actuate thermo-dependent devices, e.g., high-performance photothermal–electrical and photothermal–mechanical converters.
Wounding stress leads to anthocyanin accumulation. However, the underlying molecular mechanism remains elusive. In this study, MdWRKY40 was found to promote wounding-induced anthocyanin biosynthesis ...in association with MdMYB1 and undergo MdBT2-mediated degradation in apple.
We found that MdMYB1, a positive regulator of anthocyanin biosynthesis, was essential for the wounding-induced anthocyanin biosynthesis in apple. MdWRKY40 was identified as an MdMYB1-interacting protein, and enhanced the binding of MdMYB1 to its target genes in response to wounding.
We found that MdBT2 interacted physically with MdWRKY40 and was involved in its degradation through the 26S proteasome pathway.
Our results demonstrate that MdWRKY40 is a key modulator in the wounding-induced anthocyanin biosynthesis, which provides new insights into the regulation of wounding-induced anthocyanin biosynthesis at both the transcriptional and post-translational levels in apple.
A highly enantiodivergent organocatalytic method is disclosed for the synthesis of atropisomeric biaryls via kinetic resolution inspired by a dipeptide‐phosphonium salt‐catalyzed Atherton–Todd (A‐T) ...reaction. This flexible approach led to both R‐ and S‐enantiomers by fine‐tuning of bifunctional phosphonium with excellent selectivity factors (s) of up to 1057 and 525, respectively. The potential of newly synthesized O‐phosphorylated biaryl diols was illustrated by the synthesis of axially chiral organophosphorus compounds. Mechanistic investigations suggest that the bifunctional phosphonium halide catalyst differentiates between the in‐situ‐generated P‐species in the A‐T process, mainly involving phosphoryl chloride and phosphoric anhydride, thus leading to highly enantiodivergent O‐phosphorylation reactions. Furthermore hydrogen bonding interactions between the catalysts and phosphorus molecules were crucial in asymmetric induction.
An enantiodivergent organocatalytic kinetic resolution method has been developed, which is inspired by the Atherton–Todd (A‐T) reaction. A range of R‐ and S‐enantiomers of atropisomeric biaryls were obtained in high yields with excellent selectivity factors. The bifunctional phosphonium halide catalysts differentiate between the in‐situ‐generated P‐species in the A‐T reaction system, which results in efficient enantiodivergent O‐phosphorylation reactions.
Summary
MYB transcription factors (TFs) have been demonstrated to play diverse roles in plant growth and development through interaction with basic helix‐loop‐helix (bHLH) TFs. MdbHLH33, an apple ...bHLH TF, has been identified as a positive regulator in cold tolerance and anthocyanin accumulation by activating the expressions of MdCBF2 and MdDFR. In the present study, a MYB TF MdMYB308L was found to also positively regulate cold tolerance and anthocyanin accumulation in apple. We found that MdMYB308L interacted with MdbHLH33 and enhanced its binding to the promoters of MdCBF2 and MdDFR. In addition, an apple RING E3 ubiquitin ligase MYB30‐INTERACTING E3 LIGASE 1 (MdMIEL1) was identified to be an MdMYB308L‐interacting protein and promoted the ubiquitination degradation of MdMYB308L, thus negatively regulated cold tolerance and anthocyanin accumulation in apple. These results suggest that MdMYB308L acts as a positive regulator in cold tolerance and anthocyanin accumulation in apple by interacting with MdbHLH33 and undergoes MdMIEL1‐mediated protein degradation. The dynamic change in MYB‐bHLH protein complex seems to play a key role in the regulation of plant growth and development.
A blockchain-based smart contract has the potential to allow the performance of credible transactions without third parties. This paper presents a universal framework for a blockchain platform that ...enables peer-to-peer (P2P) energy trading in the retail electricity market. Focusing attention on seeking energy-matching pairs from the supply and demand sides, and encouraging direct energy trading between producers and consumers, the P2P energy trading mechanism is proposed. The designed multidimensional blockchain platform implements a complete energy trading process. As smart contracts strictly execute the trading and payment rules without human interaction, the security and fairness of energy trading are significantly enhanced. Case studies in the Ethereum private chain demonstrate that the proposed mechanism has obvious advantages in reflecting market quotations, balancing profits of players, and facilitating the utilization of renewables. Based on such characteristics, players are incentivized to participate in the P2P energy trading. Moreover, the authentic gas consumption and computational time to the smart contract indicate that this platform is able to achieve an efficient and effective transaction with multi-player participation.
•This paper presented a P2P energy trading mechanism with the double auction.•A universal blockchain platform for decentralized energy trading was proposed.•The designed smart contract provides secure and automatic energy trading services.•Simulation results showed the feasibility and efficiency of the proposed platform.
Effective reversal of tumor immunosuppression is of critical importance in cancer therapy. A multifunctional delivery vector that can effectively deliver CRISPR‐Cas9 plasmid for β‐catenin knockout to ...reverse tumor immunosuppression is constructed. The multi‐functionalized delivery vector is decorated with aptamer‐conjugated hyaluronic acid and peptide‐conjugated hyaluronic acid to combine the tumor cell/nuclear targeting function of AS1411 with the cell penetrating/nuclear translocation function of TAT‐NLS. Due to the significantly enhanced plasmid enrichment in malignant cell nuclei, the genome editing system can induce effective β‐catenin knockout and suppress Wnt/β‐catenin pathway, resulting in notably downregulated proteins involved in tumor progression and immunosuppression. Programmed death‐ligand 1 (PD‐L1) downregulation in edited tumor cells not only releases the PD‐1/PD‐L1 brake to improve the cancer killing capability of CD8+ T cells, but also enhances antitumor immune responses of immune cells. This provides a facile strategy to reverse tumor immunosuppression and to restore immunosurveillance and activate anti‐tumor immunity.
An aptamer/peptide‐functionalized delivery vector is constructed to effectively deliver CRISPR‐Cas9 plasmid to tumor cells for β‐catenin knockout to eliminate tumor immunosuppression. The significantly decreased programmed death‐ligand 1 (PD‐L1) in edited tumor cells not only releases the PD‐1/PD‐L1 brake to improve the cancer‐killing capability of T cells, but also enhances the antitumor immune responses of the immune cells co‐cultured with edited tumor cells.
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