The development of precious‐metal alternative electrocatalysts for oxygen reduction reaction (ORR) is highly desired for a variety of fuel cells, and single atom catalysts (SACs) have been envisaged ...to be the promising choice. However, there remains challenges in the synthesis of high metal loading SACs (>5 wt.%), thus limiting their electrocatalytic performance. Herein, a facile self‐sacrificing template strategy is developed for fabricating Co single atoms along with Co atomic clusters co‐anchored on porous‐rich nitrogen‐doped graphene (Co SAs/AC@NG), which is implemented by the pyrolysis of dicyandiamide with the formation of layered g‐C3N4 as sacrificed templates, providing rich anchoring sites to achieve high Co loading up to 14.0 wt.% in Co SAs/AC@NG. Experiments combined with density functional theory calculations reveal that the co‐existence of Co single atoms and clusters with underlying nitrogen doped carbon in the optimized Co40SAs/AC@NG synergistically contributes to the enhanced electrocatalysis for ORR, which outperforms the state‐of‐the‐art Pt/C catalysts with presenting a high half‐wave potential (E1/2 = 0.890 V) and robust long‐term stability. Moreover, the Co40SAs/AC@NG presents excellent performance in Zn–air battery with a high‐peak power density (221 mW cm−2) and strong cycling stability, demonstrating great potential for energy storage applications.
High‐loading Co single atoms and Co atomic clusters co‐anchored on porous‐rich nitrogen‐doped graphene (Co SAs/AC@NG) is constructed via a facile self‐sacrificing template strategy. The Co40SAs/AC@NG catalyst demonstrates remarkable performance with a half‐wave potential of 0.890 V for oxygen reduction reaction and a large power density of 221 mW cm−2 toward Zn–air battery.
Production of hydrogen by electrochemical water splitting has been hindered by the high cost of precious metal catalysts, such as Pt, for the hydrogen evolution reaction (HER). In this work, novel ...hierarchical β‐Mo2C nanotubes constructed from porous nanosheets have been fabricated and investigated as a high‐performance and low‐cost electrocatalyst for HER. An unusual template‐engaged strategy has been utilized to controllably synthesize Mo‐polydopamine nanotubes, which are further converted into hierarchical β‐Mo2C nanotubes by direct carburization at high temperature. Benefitting from several structural advantages including ultrafine primary nanocrystallites, large exposed surface, fast charge transfer, and unique tubular structure, the as‐prepared hierarchical β‐Mo2C nanotubes exhibit excellent electrocatalytic performance for HER with small overpotential in both acidic and basic conditions, as well as remarkable stability.
From the same sheet: Hierarchical β‐Mo2C nanotubes constructed of ultrathin nanosheets are designed and synthesized. Benefitting from ultra‐small primary nanocrystallites, a large exposed surface, fast charge transfer, and unique tubular structure, the as‐prepared hierarchical β‐Mo2C nanotubes exhibit excellent electrocatalytic performance for the hydrogen evolution reaction.
Folding and unfolding are essential ways for a protein to regulate its biological activity. The misfolding of proteins usually reduces or completely compromises their biological functions, which ...eventually causes a wide range of diseases including neurodegeneration diseases, type II diabetes, and cancers. Therefore, materials that can regulate protein folding and maintain proteostasis are of significant biological and medical importance. In living organisms, molecular chaperones are a family of proteins that maintain proteostasis by interacting with, stabilizing, and repairing various non‐native proteins. In the past few decades, efforts have been made to create artificial systems to mimic the structure and biological functions of nature chaperonins. Herein, recent progress in the design and construction of materials that mimic different kinds of natural molecular chaperones is summarized. The fabrication methods, construction rules, and working mechanisms of these artificial chaperone systems are described. The application of these materials in enhancing the thermal stability of proteins, assisting de novo folding of proteins, and preventing formation of toxic protein aggregates is also highlighted and explored. Finally, the challenges and potential in the field of chaperone‐mimetic materials are discussed.
Artificial systems that mimic the functions of molecular chaperones are promising for biomedical applications. The recent state‐of‐the‐art progress in artificial chaperone systems and their applications are systematically summarized, giving deep insight into the principles and trends for the development of novel artificial chaperone systems to solve essential problems in biomedicine.
Exploring highly active and cost‐efficient single‐atom catalysts (SACs) for oxygen reduction reaction (ORR) is critical for the large‐scale application of Zn–air battery. Herein, density functional ...theory (DFT) calculations predict that the intrinsic ORR activity of the active metal of SACs follows the trend of Co > Fe > Ni ≈ Cu, in which Co SACs possess the best ORR activity due to its optimized spin density. Guided by DFT calculations, four kinds of transition metal single atoms embedded in 3D porous nitrogen‐doped carbon nanosheets (MSAs@PNCN, M = Co, Ni, Fe, Cu) are synthesized via a facile NaCl‐template assisted strategy. The resulting MSAs@PNCN displays ORR activity trend in lines with the theoretical predictions, and the Co SAs@PNCN exhibits the best ORR activity (E1/2 = 0.851 V), being comparable to that of Pt/C under alkaline conditions. X‐ray absorption fine structure (XAFS) spectra verify the atomically dispersed Co‐N4 sites are the catalytically active sites. The highly active CoN4 sites and the unique 3D porous structure contribute to the outstanding ORR performance of Co SAs@PNCN. Furthermore, the Co SAs@PNCN catalyst is employed as cathode in Zn–air battery, which can deliver a large power density of 220 mW cm–2 and maintain robust cycling stability over 530 cycles.
Four kinds of transition metal single atoms embedded in 3D porous nitrogen‐doped carbon nanosheets (MSAs@PNCN, M = Co, Ni, Fe, Cu) are constructed via a facile NaCl‐template assisted strategy. The Co SAs@PNCN catalysts demonstrate remarkable performance with a half‐wave potential of 0.851 V for oxygen reduction reaction and a large power density of 220 mW cm–2 toward Zn–air battery.
Hierarchical Fe3O4 hollow spheres constructed by nanosheets are obtained from solvothermally synthesized Fe–glycerate hollow spheres. With the unique structural features, these hierarchical Fe3O4 ...hollow spheres exhibit excellent electrochemical lithium‐storage performance.
Amidst the swift advancements in multimedia technology and artificial intelligence, the exploration and deployment of intelligent educational technologies that leverage deep learning and neural ...networks have intensified. This study introduces an innovative automatic student behavior recognition model tailored for college English translation classrooms. Utilizing Multimodal Fusion, the model employs a Histogram of Oriented Gradients (HOG) to capture the facial expression modality and Mel Frequency Cepstral Coefficients (MFCCs) to discern the linguistic modality of students. Through Linear Discriminant Analysis, the model effectively reduces the dimensionality of multimodal data, facilitating the integration of both modalities for enhanced feature fusion and decision-making processes. Following the acquisition of multimodal emotion recognition data, students evaluate the recognized emotion values, enabling the calibration of an emotion scale. This scale serves to align specific learning emotions with corresponding learning states, providing a framework to assess students’ engagement levels. A notable improvement was observed over four weeks, with the average incidence of students classified under a “positive” learning state escalating from 9.5 to 26.7. This significant rise underscores the increasing engagement and interaction within the college English translation classroom, facilitated by the Multimodal Fusion model. It illustrates the enhanced convenience for educators in managing classroom dynamics.
Bambusoideae is the only subfamily that contains woody members in the grass family, Poaceae. In phylogenetic analyses, Bambusoideae, Pooideae and Ehrhartoideae formed the BEP clade, yet the internal ...relationships of this clade are controversial. The distinctive life history (infrequent flowering and predominance of asexual reproduction) of woody bamboos makes them an interesting but taxonomically difficult group. Phylogenetic analyses based on large DNA fragments could only provide a moderate resolution of woody bamboo relationships, although a robust phylogenetic tree is needed to elucidate their evolutionary history. Phylogenomics is an alternative choice for resolving difficult phylogenies.
Here we present the complete nucleotide sequences of six woody bamboo chloroplast (cp) genomes using Illumina sequencing. These genomes are similar to those of other grasses and rather conservative in evolution. We constructed a phylogeny of Poaceae from 24 complete cp genomes including 21 grass species. Within the BEP clade, we found strong support for a sister relationship between Bambusoideae and Pooideae. In a substantial improvement over prior studies, all six nodes within Bambusoideae were supported with ≥0.95 posterior probability from Bayesian inference and 5/6 nodes resolved with 100% bootstrap support in maximum parsimony and maximum likelihood analyses. We found that repeats in the cp genome could provide phylogenetic information, while caution is needed when using indels in phylogenetic analyses based on few selected genes. We also identified relatively rapidly evolving cp genome regions that have the potential to be used for further phylogenetic study in Bambusoideae.
The cp genome of Bambusoideae evolved slowly, and phylogenomics based on whole cp genome could be used to resolve major relationships within the subfamily. The difficulty in resolving the diversification among three clades of temperate woody bamboos, even with complete cp genome sequences, suggests that these lineages may have diverged very rapidly.
In this paper, we introduce an algorithm for solving classical variational inequalities problem with Lipschitz continuous and monotone mapping in Banach space. We modify the subgradient extragradient ...methods with a new and simple iterative step size, the strong convergence of algorithm is established without the knowledge of the Lipschitz constant of the mapping. Finally, a numerical experiment is presented to show the efficiency and advantage of the proposed algorithm. Our results generalize some of the work in Hilbert spaces to Banach spaces.
Unique Co, Fe codoped holey carbon nanosheets with high surface area and abundant bimetal single atoms (CoFe@HNSs) exhibited remarkable bifunctional oxygen electrocatalytic activity (0.704 V) with ...very positive half-wave potential (0.897 V) for the ORR and small potential (1.601 V) to drive 10 mA cm
−2
for the OER, outperforming commercial Pt/C and IrO
2
, respectively. Furthermore, as the air-cathode for rechargeable Zn-air batteries, the CoFe@HNS based device exhibits a high-power density of 131.3 mW cm
−2
and long-term stability over 140 h, indicating the attractive potential of CoFe@HNSs applied in energy storage and conversion.
CoFe@HNSs exhibited bifunctional oxygen electrocatalytic activity, and exhibit a high-power density of 131.3 mW cm
−2
and long-term stability over 140 h.
Alcalase, dispase, trypsin, and flavourzyme were used to hydrolyze the extracted
seeds protein isolate (GPI). The
protein hydrolyzates (GPHs) with the maximum degree of hydrolysis (DH) and ACE ...inhibitory activity were selected, and ultra-filtered to obtain components with different molecular weights (MW) (<1 kDa, 1-3, 3-5, and 5-10 kDa). The components with MW of <1 kDa showed better ACE inhibition (IC
:0.2227 mg/mL). Purification and identification by Sephadex G-15 gel chromatography and LC-MS/MS conferred three new potential ACE inhibitory peptides TNLDWY (non-competitive suppression mode), IC
: 1.932 mM; RADFY (competitive inhibition modes), IC
:1.35 mM; RVFDGAV (competitive inhibition modes), IC
:1.006 mM. Molecular docking depicting the inhibitory mechanism for ACE inhibitory peptides indicated that the peptides bound well to ACE and interacted with amino acid residues at the ACE active site.
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