In flowering plants, sperm cells are delivered to the embryo sac by a pollen tube guided by female signals. Both the gametic and synergid cells contribute to pollen tube attraction. Synergids secrete ...peptide signals that lure the tube, while the role of the gametic cells is unknown. Previously, we showed that CENTRAL CELL GUIDANCE (CCG) is essential for pollen tube attraction in Arabidopsis thaliana, but the molecular mechanism is unclear. Here, we identified CCG BINDING PROTEIN1 (CBP1) and demonstrated that it interacts with CCG, Mediator subunits, RNA polymerase II (Pol II), and central cell-specific AGAMOUS-like transcription factors. In addition, CCG interacts with TATA-box Binding Protein 1 and Pol II as a TFIIB-like transcription factor. CBP1- knockdown ovules are defective in pollen tube attraction. Expression profiling revealed that cysteine-rich peptide (CRP) transcripts were downregulated in ccg ovules. CCG and CBP1 coregulate a subset of CRPs in the central cell and the synergids, including the attractant LURE1. CBP1 is extensively expressed in multiple vegetative tissues and specifically in the central cell in reproductive growth. We propose that CBP1, via interaction with CCG and the Mediator complex, connects transcription factors and the Pol II machinery to regulate pollen tube attraction.
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A catalytic 1,6-nucleophilic addition/annulation cascade was developed for the first time, and used to produce 27 hitherto unreported ethylene-linked 1-naphthol-imidazole pairs with generally good ...yields and complete stereoselectivity. An Ag 2 O-catalyzed reaction of yne-allenone esters with tosylmethyl isocyanide proceeded efficiently, and provided a simple and convergent protocol for the synthesis of fully substituted ( Z )-ethylenes whereas tetrasubstituted ( E )-ethylenes were obtained when ethyl isocyanoacetate was employed in this transformation. The reaction pathway consists of 2+2 cycloaddition, 1,6-nucleophilic addition and 3+2 cycloaddition, leading to continuous multiple bond-forming events including C–C and C–N bonds to construct complex molecules.
Double fertilization is a key innovation for the evolutionary success of angiosperms by which the two fertilized female gametes, the egg cell and central cell, generate the embryo and endosperm, ...respectively. The female gametophyte (embryo sac) enclosed in the sporophyte is derived from a one-celled haploid cell lineage. It undergoes successive events of mitotic divisions, cellularization, and cell specification to give rise to the mature embryo sac, which contains the two female gametes accompanied by two types of accessory cells, namely synergids and antipodals. How the cell fate of the central cell is specified has long been equivocal and is further complicated by the structural diversity of female gametophyte across plant taxa. Here, MADS-box protein AGL80 was verified as a transcriptional repressor that directly suppresses the expression of accessory cell-specific genes to specify the central cell. Further genetic rescue and phylogenetic assay of the AGL80 orthologs revealed a possible conservedmechanism in the Brassicaceae family. Results from this study provide insight into the molecular determination of the second female gamete cell in Brassicaceae.
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A general ultrathin‐nanosheet‐induced strategy for producing a 3D mesoporous network of Co3O4 is reported. The fabrication process introduces a 3D N‐doped carbon network to adsorb metal cobalt ions ...via dipping process. Then, this carbon matrix serves as the sacrificed template, whose N‐doping effect and ultrathin nanosheet features play critical roles for controlling the formation of Co3O4 networks. The obtained material exhibits a 3D interconnected architecture with large specific surface area and abundant mesopores, which is constructed by nanoparticles. Merited by the optimized structure in three length scales of nanoparticles–mesopores–networks, this Co3O4 nanostructure possesses superior performance as a LIB anode: high capacity (1033 mAh g−1 at 0.1 A g−1) and long‐life stability (700 cycles at 5 A g−1). Moreover, this strategy is verified to be effective for producing other transition metal oxides, including Fe2O3, ZnO, Mn3O4, NiCo2O4, and CoFe2O4.
A general ultrathin‐nanosheet‐induced strategy is introduced for producing 3D mesoporous network of transition metal oxides (TMOs). An N‐doped carbon network serves as the sacrificed template, which can be applied to many kinds of TMOs. The obtained material exhibits an interconnected mesopore architecture and possesses superior performance as a lithium ion anode.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A green strategy for the selective alkylation of cysteine-containing peptides in a continuous flow reactor has been developed, providing an efficient pathway to alkylated cysteine-containing peptides ...under mild conditions. This process does not need light, metal catalysts, or oxidative reagents. It provides a useful method for the modification of amino acids and peptides. As one of the low cost and synthetic versatile raw materials, the alkyl thianthenium salt can be used as an alkylation source in the preparation of alkylated cysteine-containing peptides. In addition, the microfluidics technology can shorten the reaction time and improve the efficiency, thus reducing the costs and energy consumption of the synthesis process. A series of alkylated cysteine-containing peptides (41 examples) has been synthesized here with a short residence time (14.0 min), and with good to excellent yields.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Dual-emitting luminescent MOF Eu0.05Y0.95-PTC and its hydrogel Eu0.05Y0.95-PTC@PVA-8 were used for sensing temperature over a temperature range from 303 to 383 K with high relative sensitivities and ...good recyclability.
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•Eu0.05Y0.95-PTC shows stability under both weakly acidic and alkaline conditions and multiband luminescence.•Eu0.05Y0.95-PTC@PVA-8 showed good structural integrity and retains the temperature-sensing behavior of the MOF in a flexible form.•Both them were used for sensing temperature from 303 to 383 K with high relative sensitivities and good recyclability.
In this study, we synthesized a solid solution of MOF, Eu0.05Y0.95-PTC (H3PTC represents 2, 4, 6-pyridine tricarboxylic acid) by hydrothermal reaction, which showed exceptional stability under both weakly acidic and alkaline conditions and multiband luminescence. We further prepared Eu0.05Y0.95-PTC@PVA hydrogels by immobilizing Eu0.05Y0.95-PTC into a polyvinyl alcohol (PVA) aqueous solution, which exhibited both the integrity and temperature sensing behavior of the MOF solid solution, alongside excellent mechanical performance. Both Eu0.05Y0.95-PTC and Eu0.05Y0.95-PTC@PVA-8 hydrogel displayed temperature sensing capabilities over the range from 303 to 383 K, with relative sensitivities (Sr) reaching a maximum value of 1.94 %•K−1 and 0.65 %•K−1 at 383 K, respectively, and good recyclability as well.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this article, the problem of event‐triggered adaptive asymptotic tracking control (ATC) for stochastic nonlinear systems with unknown control directions (UCDs) and full state constraints is ...concerned. It must be said that the controller design and system analysis is more complex and difficult since the existence of stochastic disturbances, UCDs and full state constraints simultaneously. By introducing the lower bound of the UCDs into the barrier Lyapunov functions, an event‐triggered adaptive MTN ATC scheme is proposed based on the boundary estimation method and a new event‐triggered control (ETC) strategy, which can achieve satisfactory asymptotic tracking performance and control performance of the system, while reduce the occupation of network resources. The simulation results not only verify the effectiveness of the proposed control scheme, but also present different tracking performances between three ETC strategies for comparison, further confirming the superiority of the proposed ETC strategy in achieving asymptotic tracking performance.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
An increasing prevalence of diabetes is known as a main risk for human health in the last future worldwide. There is limited evidence on the potential management of type 2 diabetes mellitus using ...bioactive peptides from marine organisms, besides from milk and beans. We summarized here recent advances in our understanding of the regulation of glucose metabolism using bioactive peptides from natural proteins, including regulation of insulin-regulated glucose metabolism, such as protection and reparation of pancreatic β-cells, enhancing glucose-stimulated insulin secretion and influencing the sensitivity of insulin and the signaling pathways, and inhibition of bioactive peptides to dipeptidyl peptidase IV, α-amylase and α-glucosidase activities. The present paper tried to understand the underlying mechanism involved and the structure characteristics of bioactive peptides responsible for its antidiabetic activities to prospect the utilization of rich marine organism proteins.
Sepsis is a life-threatening condition caused by pathogen infection and associated with pyroptosis. Pyroptosis occurs upon activation of proinflammatory caspases and their subsequent cleavage of ...gasdermin D (GSDMD), resulting in GSDMD N-terminal fragments that form membrane pores to induce cell lysis. Here, we show that antioxidant defense enzyme glutathione peroxidase 4 (GPX4) and its ability to decrease lipid peroxidation, negatively regulate macrophage pyroptosis, and septic lethality in mice. Conditional Gpx4 knockout in myeloid lineage cells increases lipid peroxidation-dependent caspase-11 activation and GSDMD cleavage. The resultant N-terminal GSDMD fragments then trigger macrophage pyroptotic cell death in a phospholipase C gamma 1 (PLCG1)-dependent fashion. Administration of the antioxidant vitamin E that reduces lipid peroxidation, chemical inhibition of PLCG1, or genetic Caspase-11 deletion or Gsdmd inactivation prevents polymicrobial sepsis in Gpx4−/− mice. Collectively, this study suggests that lipid peroxidation drives GSDMD-mediated pyroptosis and hence constitutes a potential therapeutic target for lethal infection.
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•Gpx4 deficiency in myeloid cells increases severity of polymicrobial sepsis in mice•Caspase-11-dependent pyroptosis mediates septic death in Gpx4Mye−/− mice•GPX4 decreases lipid peroxidation to block PLCG1-mediated GSDMD activity and pyroptosis•Antioxidant activity of vitamin E promotes survival during sepsis in Gpx4Mye−/− mice
Kang et al. demonstrate that glutathione peroxidase 4 (GPX4) serves a protective role in mice undergoing septic shock. Myeloid-specific deficiency of Gpx4 coordinates lipid peroxidation-dependent caspase-11 activation and gasdermin D-mediated pyroptosis during polymicrobial sepsis. Vitamin E administration reverses Gpx4Mye−/− susceptibility, thereby revealing a potential target for therapeutic intervention for lethal infection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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