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Single-atom catalysts (SACs) have emerged as a frontier in heterogeneous catalysis due to the well-defined active site structure and the maximized metal atom utilization. Nevertheless, the robustness of SACs remains a critical concern for practical applications. Herein, we report a highly active, selective and robust Ru SAC which was synthesized by pyrolysis of ruthenium acetylacetonate and N/C precursors at 900 °C in N 2 followed by treatment at 800 °C in NH 3 . The resultant Ru 1 -N 3 structure exhibits moderate capability for hydrogen activation even in excess NH 3 , which enables the effective modulation between transimination and hydrogenation activity in the reductive amination of aldehydes/ketones towards primary amines. As a consequence, it shows superior amine productivity, unrivalled resistance against CO and sulfur, and unexpectedly high stability under harsh hydrotreating conditions compared to most SACs and nanocatalysts. This SAC strategy will open an avenue towards the rational design of highly selective and robust catalysts for other demanding transformations. Single-atom catalyst (SAC) has emerged as a frontier in heterogeneous catalysis yet its robustness remains a critical concern. Here, a highly active, selective and robust Ru 1 -N 3 SAC is explored for a challenging reaction, reductive amination of aldehydes/ketones for synthesis of primary amines.

The catalytic hydrogenation of nitroarenes is an environmentally benign technology for the production of anilines, which are key intermediates for manufacturing agrochemicals, pharmaceuticals and dyes. Most of the precious metal catalysts, however, suffer from low chemoselectivity when one or more reducible groups are present in a nitroarene molecule. Herein we report FeO x -supported platinum single-atom and pseudo-single-atom structures as highly active, chemoselective and reusable catalysts for hydrogenation of a variety of substituted nitroarenes. For hydrogenation of 3-nitrostyrene, the catalyst yields a TOF of ~1,500 h −1 , 20-fold higher than the best result reported in literature, and a selectivity to 3-aminostyrene close to 99%, the best ever achieved over platinum group metals. The superior performance can be attributed to the presence of positively charged platinum centres and the absence of Pt–Pt metallic bonding, both of which favour the preferential adsorption of nitro groups. Reduction of nitroarenes in the presence of other reducible groups is challenging, as is simultaneously achieving high selectivity and activity. Here, the authors report supported single-atom and pseudo-single-atom platinum catalysts with excellent activity and high degrees of chemoselectivity.

Heterogeneous single-atom catalyst (SAC) opens a unique entry to establishing structure–performance relationship at the molecular level similar to that in homogeneous catalysis. The challenge lies in manipulating the coordination chemistry of single atoms without changing single-atom dispersion. Here, we develop an efficient synthetic method for SACs by using ethanediamine to chelate Pt cations and then removing the ethanediamine by a rapid thermal treatment (RTT) in inert atmosphere. The coordination chemistry of Pt single atoms on a Fe 2 O 3 support is finely tuned by merely adjusting the RTT temperature. With the decrease in Pt-O coordination number, the oxidation state of Pt decreases, and consequently the hydrogenation activity increases to a record level without loss of chemoselectivity. The tunability of the local coordination chemistry, oxidation states of the metal, and the catalytic performance of single atoms reveals the unique role of SACs as a bridge between heterogeneous and homogeneous catalysis. In single-atom catalysts (SACs), little is known about how the coordination structure of single atoms affects the catalytic performance. Here, the authors discover that in Pt 1 /Fe 2 O 3 SAC, the coordination number of the first shell Pt-O is well correlated with the Pt electronic property and the hydrogenation activity.

Cubosomes, a product of nanobioengineering, are self-structured lipid nanoparticles that act like drug-loaded theranostic probes. Here, we describe a simple method for the preparation of combinatorial drug-loaded cubosomes with, proof-of-principle, therapeutic effect against cancer cells, along with diagnostic capabilities. Anticancer drugs cisplatin and paclitaxel were loaded in the cubosomes in combination. The cubosomes were coated with a layer of poly-Ɛ-lysine, which helped avoid the initial burst release of drug and allowed for a slow and sustained release for better efficacy. Cubosomes were imaged by transmission electron microscope, and their dispersion analyzed in vitro by differential scanning calorimetric and X-ray diffractogram studies. The microscopic images depicted spherical polyangular structures, which are easily distinguishable. The analyses revealed that the drug is uniformly dispersed all through the cubosomes. Further characterization was carried out by zeta-potential measurement, in vitro release, and entrapment efficiency studies. The in vitro studies established that the coating of cubosomes successfully reduced the burst release of drugs initially and confirmed a slow, sustained release over increased time. Comparative cytotoxicity of coated, uncoated, and blank cubosomes was evaluated, using human hepatoma HepG2 cell line, and the formulations were found to be entirely nontoxic, similar to the blank ones. The therapeutic efficiency of the cubosomes against HeLa cells was confirmed by the impedance measurement and fluorescent imaging. Furthermore, the reduction in impedance in cells treated with coated combinatorial cubosomes proved the impairment of HeLa cells, as confirmed by fluorescence microscopy.

Background The taxonomic ambiguity caused by species complexes (closely related species with overlapping phenotypic traits but distinct genetic profiles) has increasingly garnered attention. Cupriavidus species hold environmental, industrial, and clinical relevance, yet unresolved species complexes within this genus may limit insights into their pathogenesis. Results Six species ( C. alkaliphilus , C. basilensis , C. gilardii , C. oxalaticus , C. necator , and C. taiwanensis ) were identified as species complexes, comprising 36 correctly classified strains and 42 mislabeled strains. More importantly, C. alkaliphilus and a subset of C. taiwanensis are phylogenetically grouped together. We, therefore, propose a genome-based taxonomic framework to reclassify these species. For mislabeled strains, the 10 strains labeled as C. taiwanensis were reassigned to C. alkaliphilus ; the remaining 32 strains were classified as 11 unnominated genomic groups. C. metallidurans and C. pauculus retained current classifications. The open pan-genome and prevalence of mobile genetic elements indicated high genetic variation in Cupriavidus . We identified 47 genes related to virulence factors. Virulence factors in almost all Cupriavidus strains were related to the antimicrobial activity ( acrB ), biofilm ( adeG , algU ), stress survival ( clpP , katA , sodB , ureA , ureB , and ureG ), adherence ( htpB , kdsA ), and others ( icl ); the opportunistic pathogens C. gilardii and C. metallidurans contained extra virulence genes ( plc-2 ). Furthermore, six types of secretion systems (T1SS-T6SS) were identified in Cupriavidus. T2SS was conserved across all eight species; the other secretion systems presented diverse distribution. Interestingly, C. gilardii possesses two divergent T3SS clusters. Finally, emre , responsible for the efflux pump of aminoglycoside antibiotics, is a major antibiotic resistance gene of Cupriavidus strains. Other genes related to aminoglycosides, β-lactam, fosfomycin, and multidrug resistance are species-specific among opportunistic pathogens individually. Conclusions This study addresses the taxonomic ambiguities arising from species complexes within 97 strains of Cupriavidus and proposes a genome-based taxonomic framework based on phylogenomic analysis. Beyond classification, we advance insights into the genus’s pathogenesis by delineating virulence-related genetic profiles, including conserved and species-specific virulence factors, secretion systems, and antibiotic resistance genes. Collectively, this work establishes a genomic foundation for understanding phylogenetic relationships and a comparative framework to explore pathogenicity across 97 strains of Cupriavidus .

Organic cocrystals possess valuable properties owing to the synergistic effect of the individual components. However, the growth of molecular cocrystals is still in its primary stage. Here we develop a microspacing in-air sublimation method to grow organic cocrystals, and furthermore to realize morphology control on them, which is essential for structure–property relations. A series of polycyclic aromatic hydrocarbon (PAH)‒1,2,4,5-tetracyanobenzene (TCNB) complexes cocrystals are grown directly on the substrate, with the morphology tunable from 1D needle-like to 2D plate-like on demand. Spatially resolved photoluminescence spectra analyses on different cocrystals display morphology dependent and anisotropic optical waveguiding properties. In situ observation and energy calculations of the crystallization processes reveal the formation mechanism being from a competition between growth kinetics-defined crystal habit and the thermodynamics driving force. This growth technique may serve the future demand for tunable morphology organic cocrystals in different functional applications. Organic cocrystals have interesting properties owing to synergistic effects of the individual components but development of effective growth methods for molecular cocrystals is still in its primary stage. Here the authors demonstrate a sublimation method which allows growing organic cocrystals with controlled morphology.

In humans, the cytosolic glutathione S-transferase (GST) family of proteins is encoded by 16 genes presented in seven different classes. GSTs exhibit remarkable structural similarity with some overlapping functionalities. As a primary function, GSTs play a putative role in Phase II metabolism by protecting living cells against a wide variety of toxic molecules by conjugating them with the tripeptide glutathione. This conjugation reaction is extended to forming redox sensitive post-translational modifications on proteins: S-glutathionylation. Apart from these catalytic functions, specific GSTs are involved in the regulation of stress-induced signaling pathways that govern cell proliferation and apoptosis. Recently, studies on the effects of GST genetic polymorphisms on COVID-19 disease development revealed that the individuals with higher numbers of risk-associated genotypes showed higher risk of COVID-19 prevalence and severity. Furthermore, overexpression of GSTs in many tumors is frequently associated with drug resistance phenotypes. These functional properties make these proteins promising targets for therapeutics, and a number of GST inhibitors have progressed in clinical trials for the treatment of cancer and other diseases.

The sustainable production of value-added N-heterocycles from available biomass allows to reduce the reliance on fossil resources and creates possibilities for economically and ecologically improved synthesis of fine and bulk chemicals. Herein, we present a unique Ru 1 Co NP /HAP surface single-atom alloy (SSAA) catalyst, which enables a new type of transformation from the bio-based platform chemical furfural to give N-heterocyclic piperidine. In the presence of NH 3 and H 2 , the desired product is formed under mild conditions with a yield up to 93%. Kinetic studies show that the formation of piperidine proceeds via a series of reaction steps. Initially, in this cascade process, furfural amination to furfurylamine takes place, followed by hydrogenation to tetrahydrofurfurylamine (THFAM) and then ring rearrangement to piperidine. DFT calculations suggest that the Ru 1 Co NP SSAA structure facilitates the direct ring opening of THFAM resulting in 5-amino-1-pentanol which is quickly converted to piperidine. The value of the presented catalytic strategy is highlighted by the synthesis of an actual drug, alkylated piperidines, and pyridine. The synthesis of nitrogen-containing heterocycles from biomass is scarcely known. Here, the authors report a strategy for the N-heterocyclic piperidines synthesis by one-pot amination of the bio-based furfural utilizing a Ru 1 Co NP /HAP surface single-atom alloy catalyst.

Reppe carbonylation of acetylene is an atom-economic and non-petroleum approach to synthesize acrylic acid and acrylate esters, which are key intermediates in the textile, leather finishing, and polymer industries. In the present work, a noble metal-free Co@SiO2 catalyst was prepared and evaluated in the methoxycarbonylation reaction of acetylene. It was discovered that pretreatment of the catalyst by different reductants (i.e., C2H2, CO, H2, and syngas) greatly improved the catalytic activity, of which Co/SiO2-H2 demonstrated the best performance under conditions of 160 °C, 0.05 MPa C2H2, 4 MPa CO, and 1 h, affording a production rate of 4.38 gMA+MP gcat−1 h−1 for methyl acrylate (MA) and methyl propionate (MP) and 0.91 gDMS gcat−1 h−1 for dimethyl succinate (DMS), respectively. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectra of CO adsorption (CO-DRIFTS) measurements revealed that an H2 reduction decreased the size of the Co nanoparticles and promoted the formation of hollow architectures, leading to an increase in the metal surface area and CO adsorption on the catalyst. The hot filtration experiment confirmed that Co2(CO)8 was generated in situ during the reaction or at the pre-activation stage, which served as the genuine active species. Our work provides a facile and convenient approach to the in situ synthetization of Co2(CO)8 for a Reppe carbonylation reaction.

Rolling bearing is the core component of industrial machines, but it is difficult for common single signal source-based fault diagnosis methods to ensure reliable results since sensor signals are vulnerable to the pollution of background noises and the attenuation of transmitted information. Recently, multi-source information-based fault diagnosis methods have become popular, but the information redundancy between multiple signals is a tough problem that will negatively impact the representational capacity of deep learning algorithms and the precision of fault diagnosis methods. Besides that, the characteristics of various signals are actually different, but this problem was usually omitted by researchers, and it has potential to further improve the diagnosing performance by adaptively adjusting the feature extraction process for every input signal source. Aimed at solving the above problems, a novel model for bearing fault diagnosis called multi-branch selective fusion deep residual network is proposed in this paper. The model adopts a multi-branch structure design to enable every input signal source to have a unique feature processing channel, avoiding the information of multiple signal sources blindly coupled by convolution kernels. And in each branch, different convolution kernel sizes are assigned according to the characteristics of every input signal, fully digging the precious fault components on respective information sources. Lastly, the dropout technique is used to randomly throw out some activated neurons, alleviating the redundancy and enhancing the quality of the multiscale features extracted from different signals. The proposed method was experimentally compared with other intelligent methods on two authoritative public bearing datasets, and the experimental results prove the feasibility and superiority of the proposed model.