Covalent organic frameworks (COF) are complex functional systems constructed with atomic precision by linking well‐defined building blocks through robust covalent bonds. β‐cyclodextrin (β‐CD) is a ...most employed supramolecule which bears a hydrophobic cavity guiding molecular specific recognitions. Building COF with asymmetric β‐CD linkers is challenging and has never been reported. Here, β‐CD COF is grown with heptakis(6‐amino‐6‐deoxy)‐β‐CD and terephthalaldehyde in green solvents of water and ethanol at room temperature. The COF is characterized by powder X‐ray diffraction, which matches well with the simulated crystal structure. Weaving β‐CD into a framework through reticular chemistry allows the integration of a large amount of β‐CD units (50 mol %), much higher than β‐CD polymers. The β‐CD COF has larger surface area, more uniform pore size, and higher thermal stability than the non‐crystalline β‐CD polymer produced by the same reagents. Finally, the β‐CD COF holds abundant specific interaction sites enabling selective molecular adsorption.
Porous β‐cyclodextrin (CD) cubic poles: The first success of using an asymmetric supramolecular building block, β‐CD, for the construction of a covalent organic framework. The framework is built from heptakis(6‐amino‐6‐deoxy)‐β‐CD and terephthalaldehyde under acid catalysis in aqueous ethanol at room temperature. It exhibits a morphology of cubic poles, with an average width of 125 nm. The material has a high surface area, uniform pore size, and abundant β‐CD units, enabling highly selective molecular adsorption in water.
Root exudate signals in plant–plant interactions Wang, Nan‐Qi; Kong, Chui‐Hua; Wang, Peng ...
Plant, cell & environment/Plant, cell and environment,
April 2021, Volume:
44, Issue:
4
Journal Article
Peer reviewed
Open access
Plant‐to‐plant signalling is a key mediator of interactions among plant species. Plants can perceive and respond to chemical cues emitted from their neighbours, altering survival and performance, ...impacting plant coexistence and community assembly. An increasing number of studies indicate root exudates as key players in plant‐to‐plant signalling. Root exudates mediate root detection and behaviour, kin recognition, flowering and production, driving inter‐ and intra‐specific facilitation in cropping systems and mixed‐species plantations. Altered interactions may be attributed to the signalling components within root exudates. Root ethylene, strigolactones, jasmonic acid, (‐)‐loliolide and allantoin are signalling chemicals that convey information on local conditions in plant–plant interactions. These root‐secreted signalling chemicals appear ubiquitous in plants and trigger a series of belowground responses inter‐ and intra‐specifically, involving molecular events in biosynthesis, secretion and action. The secretion of root signals, mainly mediated by ATP‐binding cassette transporters, is critical. Root‐secreted signalling chemicals and their molecular mechanisms are rapidly revealing a multitude of fascinating plant–plant interactions. However, many root signals, particularly species‐specific signals and their underlying mechanisms, remain to be uncovered due to methodological limitations and root‐soil interactions. A thorough understanding of root‐secreted chemical signals and their mechanisms will offer many ecological implications and potential applications for sustainable agriculture.
This review deals with the roles of root exudates in plant‐to‐plant signalling, and the identity of root‐secreted chemical signals and their molecular mechanisms, providing fascinating insights into communication and interactions among plants.
AMP-activated protein kinase (AMPK) is a metabolic sensor in mammals that is activated when ATP levels in the cell decrease. AMPK is a heterotrimeric protein that comprises 3 subunits, each of which ...has multiple phosphorylation sites that play critical roles in the regulation of either anabolism or catabolism by directly phosphorylating proteins or modulating gene transcription in multiple pathways, such as synthesis, oxidation and lipolysis of lipid. Research focused on the phosphorylation sites that are involved in lipid metabolism will lead to a better recognition of the role of AMPK in therapeutics for several common diseases. In this review, close attention is paid to the recent research on the structure, and multisite phosphorylation of AMPK subunits, as well as AMPK regulation of lipid metabolism via phosphorylation of related molecules.
People from different cultures often tell diverse stories about their past experiences. Research in the past two decades has revealed systematic differences in the content (self-focus vs ...other-focus), structure (specific vs general), valence (positive vs negative), accessibility (memory density and detailedness), developmental origin (age and density of earliest childhood memories), and functional usage (self-definition, relationship maintenance, behavioral guidance, and emotion regulation) of autobiographical memory across cultures. I outline a cultural dynamic theory of autobiographical memory that aims to synthesize the findings and provide a coherent guide to future investigation. The theory posits that (1) autobiographical memory takes place in the dynamic transaction between an active individual and his or her changing environment; (2) it is situated in culturally conditioned time and space over a multitude of timescales; and (3) it develops in the process of children acquiring cultural knowledge about the self and the purpose of the past through early socialization. I further discuss how the theory can provide insights into collective memory and future simulation.
Detecting coherent groups is fundamentally important for crowd behavior analysis. In the past few decades, plenty of works have been conducted on this topic, but most of them have limitations due to ...the insufficient utilization of crowd properties and the arbitrary processing of individuals. In this study, a Multiview-based Parameter Free framework (MPF) is proposed. Based on the L1-norm and L2-norm, we design two versions of the multiview clustering method, which is the main part of the proposed framework. This paper presents the contributions on three aspects: (1) a new structural context descriptor is designed to characterize the structural properties of individuals in crowd scenes; (2) a self-weighted multiview clustering method is proposed to cluster feature points by incorporating their orientation and context similarities; and (3) a novel framework is introduced for group detection, which is able to determine the group number automatically without any parameter or threshold to be tuned. The effectiveness of the proposed framework is evaluated on real-world crowd videos, and the experimental results show its promising performance on group detection. In addition, the proposed multiview clustering method is also evaluated on a synthetic dataset and several standard benchmarks, and its superiority over the state-of-the-art competitors is demonstrated.
A Au55 nanocluster with the composition of Au55(p‐MBT)24(Ph3P)6(SbF6)3 (p‐MBT=4‐methylbenzenethiolate) is synthesized via direct reduction of gold‐phosphine and gold‐thiolate precursors. ...Single‐crystal X‐ray diffraction reveals that this Au55 nanocluster features a face‐centered cubic (fcc) Au55 kernel, different from the well‐known two‐shell cuboctahedral arrangement in Au55(Ph3P)12Cl6. The Au55 cluster shows a wide optical absorption band with optical energy gap (Eg=1.28 eV). It is found that the exclusion of chloride is crucial for the formation of the title cluster, otherwise rod‐like Au25(SR)5(PPh3)10Cl22+ is obtained. The strategy to run synthetic reaction in the absence of halide leads to new members of phosphine/thiolate co‐protected metal nanoclusters. The Au55 nanocluster exhibits high catalytic activity and selectivity for electrochemical reduction of CO2 to CO; the Faradaic efficiency (FE) reaches 94.1 % at −0.6 V vs. reversible hydrogen electrode (RHE).
The gold nanocluster Au55(p‐MBT)24(Ph3P)6(SbF6)3 (p‐MBT=4‐methylbenzenethiolate) features a face‐centered cubic Au55 kernel. This cluster exhibits high catalytic activity and selectivity for electrochemical reduction of CO2 to CO, and the Faradaic efficiency (FE) reaches 94.1 % at −0.6 V. The exclusion of chloride is an effective strategy to generate new members of ligand‐protected metal nanoclusters.
Rheumatoid arthritis (RA) is an autoimmune disease that exhibits a high degree of heterogeneity, marked by unpredictable disease flares and significant variations in the response to available ...treatments. The lack of optimal stratification for RA patients may be a contributing factor to the poor efficacy of current treatment options. The objective of this study is to elucidate the molecular characteristics of RA through the utilization of mitochondrial genes and subsequently construct and authenticate a diagnostic framework for RA. Mitochondrial proteins were obtained from the MitoCarta database, and the R package limma was employed to filter for differentially expressed mitochondrial genes (MDEGs). Metascape was utilized to perform enrichment analysis, followed by an unsupervised clustering algorithm using the ConsensuClusterPlus package to identify distinct subtypes based on MDEGs. The immune microenvironment, biological pathways, and drug response were further explored in these subtypes. Finally, a multi-biomarker-based diagnostic model was constructed using machine learning algorithms. Utilizing 88 MDEGs present in transcript profiles, it was possible to classify RA patients into three distinct subtypes, each characterized by unique molecular and cellular signatures. Subtype A exhibited a marked activation of inflammatory cells and pathways, while subtype C was characterized by the presence of specific innate lymphocytes. Inflammatory and immune cells in subtype B displayed a more modest level of activation (Wilcoxon test P < 0.05). Notably, subtype C demonstrated a stronger correlation with a superior response to biologics such as infliximab, anti-TNF, rituximab, and methotrexate/abatacept (P = 0.001) using the fisher test. Furthermore, the mitochondrial diagnosis SVM model demonstrated a high degree of discriminatory ability in distinguishing RA in both training (AUC = 100%) and validation sets (AUC = 80.1%). This study presents a pioneering analysis of mitochondrial modifications in RA, offering a novel framework for patient stratification and potentially enhancing therapeutic decision-making.
Abstract
Rechargeable aqueous zinc-ion batteries are a promising candidate for next-generation energy storage devices. However, their practical application is limited by the severe safety issue ...caused by uncontrollable dendrite growth on zinc anodes. Here we develop faceted titanium dioxide with relatively low zinc affinity, which can restrict dendrite formation and homogenize zinc deposition when served as the protective layer on zinc anodes. The as-prepared zinc anodes can be stripped and plated steadily for more than 460 h with low voltage hysteresis and flat voltage plateau in symmetric cells. This work reveals the key role of crystal orientation in zinc affinity and its internal mechanism is suitable for various crystal materials applied in the surface modification of other metal anodes such as lithium and sodium.
Developing highly efficient and low‐cost photocatalysts for overall water splitting has long been a pursuit for converting solar power into clean hydrogen energy. Herein, we demonstrate that a ...nonstoichiometric nickel–cobalt double hydroxide can achieve overall water splitting by itself upon solar light irradiation, avoiding the consumption of noble‐metal co‐catalysts. We employed an intensive laser to ablate a NiCo alloy target immersed in alkaline solution, and produced so‐called L‐NiCo nanosheets with a nonstoichiometric composition and O2−/Co3+ ions exposed on the surface. The nonstoichiometric composition broadens the band gap, while O2− and Co3+ ions boost hydrogen and oxygen evolution, respectively. As such, the photocatalyst achieves a H2 evolution rate of 1.7 μmol h−1 under AM 1.5G sunlight irradiation and an apparent quantum yield (AQE) of 1.38 % at 380 nm.
A single‐phase photocatalyst, a hydrogen‐deficient nickel–cobalt double hydroxide, was generated by laser ablation. This photocatalyst can drive overall water splitting under solar light irradiation in the absence of sacrificial agents and noble metal co‐catalysts because of its unique composition and structure, with partially removed hydrogen atoms as well as O2− and Co3+ ions exposed on the surface.
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