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Hydrogen is increasingly being discussed as clean energy for the goal of net-zero carbon emissions, applied in the proton-exchange-membrane fuel cells (PEMFC). The preferential oxidation of CO (PROX) in hydrogen is a promising solution for hydrogen purification to avoid catalysts from being poisoned by the trace amount of CO in hydrogen-rich fuel gas. Here, we report the fabrication of a novel bimetallic Pt-Fe catalyst with ultralow metal loading, in which fully-exposed Pt clusters bonded with neighbor atomically dispersed Fe atoms on the defective graphene surface. The fully-exposed PtFe cluster catalyst could achieve complete elimination of CO through PROX reaction and almost 100% CO selectivity, while maintaining good stability for a long period. It has the mass-specific activity of 6.19 (mol CO )*(g Pt ) -1 *h -1 at room temperature, which surpasses those reported in literatures. The exhaustive experimental results and theoretical calculations reveal that the construction of fully-exposed bimetallic Pt-Fe cluster catalysts with maximized atomic efficiency and abundant interfacial sites could facilitate oxygen activation on unsaturated Fe species and CO adsorption on electron-rich Pt clusters to hence the probability of CO oxidation, leading to excellent reactivity in practical applications., (© 2022. The Author(s).)

The atomically dispersed metal catalyst or single-atom catalyst (SAC) with the utmost metal utilization efficiency shows excellent selectivity toward ethylene compared to the metal nanoparticles catalyst in the acetylene semi-hydrogenation reaction. However, these catalysts normally work at relatively high temperatures. Achieving low-temperature reactivity while preserving high selectivity remains a challenge. To improve the intrinsic reactivity of SACs, rationally tailoring the coordination environments of the first metal atom by coordinating it with a second neighboring metal atom affords an opportunity. Here, we report the fabrication of a dual-atom catalyst (DAC) that features a bonded Pd 1 -Cu 1 atomic pair anchoring on nanodiamond graphene (ND@G). Compared to the single-atom Pd or Cu catalyst, it exhibits increased reactivity at a lower temperature, with 100% acetylene conversion and 92% ethylene selectivity at 110 °C. This work provides a strategy for designing DACs for low-temperature hydrogenation by manipulating the coordination environment of catalytic sites at the atomic level.

Having the excellent catalytic performance, single atom catalysts (SACs) arouse extensive research interest. However, the application of SACs is hindered by the lack of versatile and scalable preparation approaches. Here, we show a precursor-atomization strategy to produce SACs, involving the spray of droplets of solutions containing metal precursors onto support surface through ultrasonic atomization and the subsequent calcination. This approach is versatile to successful synthesis of a series of catalysts, including 19 SACs with different metal sites and supports and 3 derivatives of SACs (single atom alloys, double atom catalysts and bi-metallic SACs). Furthermore, it can be scaled up by a homemade production line with productivity over 1 kg day -1 , and the well-controlled catalyst uniformity is evidenced by the identical characterization results and catalytic properties in Suzuki-Miyaura cross-coupling. This strategy lays a foundation for further investigation and may accelerate the trend from basic research to industrial applications of SACs., (© 2022. The Author(s).)

Exploring antibacterial nanomaterials with excellent catalytic antibacterial properties has always been a hot research topic. However, the construction of nanomaterials with robust antibacterial activity at the atomic level remains a great challenge. Here a fully-exposed Pd cluster atomically-dispersed on nanodiamond-graphene (Pd n /ND@G) with excellent catalytic antibacterial properties is reported. The fully-exposed Pd cluster nanozyme provides atomically-dispersed Pd cluster sites that facilitate the activation of oxygen. Notably, the oxidase-like catalytic performance of the fully-exposed Pd cluster nanozyme is much higher than that of Pd single-atom oxidase mimic, Pd nanoparticles oxidase mimic and even the previously reported palladium-based oxidase mimics. Under the density functional theory (DFT) calculations, the Pd cluster sites can efficiently catalyze the decomposition of oxygen to generate reactive oxygen species, resulting in strong antibacterial properties. This research provides a valuable insight to the design of novel oxidase mimic and antibacterial nanomaterial., (© 2022 Wiley-VCH GmbH.)

Hydrogen storage by means of catalytic hydrogenation of suitable organic substrates helps to elevate the volumetric density of hydrogen energy. In this regard, utilizing cheaper industrial crude hydrogen to fulfill the goal of hydrogen storage would show economic attraction. However, because CO impurities in crude hydrogen can easily deactivate metal active sites even in trace amounts such a process has not yet been realized. Here, we develop a robust RuNi/TiO 2 catalyst that enables the efficient hydrogenation of toluene to methyl-cyclohexane under simulated crude hydrogen feeds with 1000-5000 ppm CO impurity at around 180 °C under atmospheric pressure. We show that the co-localization of Ru and Ni species during reduction facilitated the formation of tightly coupled metallic Ru-Ni clusters. During the catalytic hydrogenation process, due to the distinct bonding properties, Ru and Ni served as the active sites for CO methanation and toluene hydrogenation respectively. Our work provides fresh insight into the effective utilization and purification of crude hydrogen for the future hydrogen economy., (© 2022. The Author(s).)

Direct conversion of methane into value-added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO 2 suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co-catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar. Millimole level yields of methanol were reached with the selectivity higher than 99 % using the Rh/TiO 2 catalysts with the promotion of the copper cation. CO was the reductive agent to generate H 2 from H 2 O, which led to the formation of H 2 O 2 through the reaction of H 2 and O 2 . Atomically dispersed Rh activated the C-H bond in CH 4 and catalyzed the oxidation using H 2 O 2 . Copper cations maintained the low-valence state of Rh. Moreover, copper acted as a scavenger for suppressing the overoxidation, thus leading to the high selectivity of methanol., (© 2022 Wiley-VCH GmbH.)

The product selectivity in catalytic hydrogenation of nitriles is strongly correlated with the structure of the catalyst. In this work, two types of atomically dispersed Pd species stabilized on the defect-rich nanodiamond-graphene (ND@G) hybrid support: single Pd atoms (Pd 1 /ND@G) and fully exposed Pd clusters with average three Pd atoms (Pd n /ND@G), were fabricated. The two catalysts show distinct difference in the catalytic transfer hydrogenation of nitriles. The Pd 1 /ND@G catalyst preferentially generates secondary amines (Turnover frequency (TOF@333 K 709 h -1 , selectivity >98%), while the Pd n /ND@G catalyst exhibits high selectivity towards primary amines (TOF@313 K 543 h -1 , selectivity >98%) under mild reaction conditions. Detailed characterizations and density functional theory (DFT) calculations show that the structure of atomically dispersed Pd catalysts governs the dissociative adsorption pattern of H 2 and also the hydrogenation pathway of the benzylideneimine (BI) intermediate, resulting in different product selectivity over Pd 1 /ND@G and Pd n /ND@G, respectively. The structure-performance relationship established over atomically dispersed Pd catalysts provides valuable insights for designing catalysts with tunable selectivity., (© 2021. The Author(s).)

Metal nanoparticle (NP), cluster and isolated metal atom (or single atom, SA) exhibit different catalytic performance in heterogeneous catalysis originating from their distinct nanostructures. To maximize atom efficiency and boost activity for catalysis, the construction of structure-performance relationship provides an effective way at the atomic level. Here, we successfully fabricate fully exposed Pt 3 clusters on the defective nanodiamond@graphene (ND@G) by the assistance of atomically dispersed Sn promoters, and correlated the n-butane direct dehydrogenation (DDH) activity with the average coordination number (CN) of Pt-Pt bond in Pt NP, Pt 3 cluster and Pt SA for fundamentally understanding structure (especially the sub-nano structure) effects on n-butane DDH reaction at the atomic level. The as-prepared fully exposed Pt 3 cluster catalyst shows higher conversion (35.4%) and remarkable alkene selectivity (99.0%) for n-butane direct DDH reaction at 450 °C, compared to typical Pt NP and Pt SA catalysts supported on ND@G. Density functional theory calculation (DFT) reveal that the fully exposed Pt 3 clusters possess favorable dehydrogenation activation barrier of n-butane and reasonable desorption barrier of butene in the DDH reaction.

Synthesis of atomically dispersed catalysts with high metal loading and thermal stability is challenging but particularly valuable for industrial application in heterogeneous catalysis. Here, we report a facile synthesis of a thermally stable atomically dispersed Ir/α-MoC catalyst with metal loading as high as 4 wt%, an unusually high value for carbide supported metal catalysts. The strong interaction between Ir and the α-MoC substrate enables high dispersion of Ir on the α-MoC surface, and modulates the electronic structure of the supported Ir species. Using quinoline hydrogenation as a model reaction, we demonstrate that this atomically dispersed Ir/α-MoC catalyst exhibits remarkable reactivity, selectivity and stability, for which the presence of high-density isolated Ir atoms is the key to achieving high metal-normalized activity and mass-specific activity. We also show that the water-promoted quinoline hydrogenation mechanism is preferred over the Ir/α-MoC, and contributes to high selectivity towards 1,2,3,4-tetrahydroquinoline. The present work demonstrates a new strategy in constructing a high-loading atomically dispersed catalyst for the hydrogenation reaction., (© The Author(s) 2021. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)

Abstract: The present study aimed to investigate the correlation of long non-coding RNA nuclear-enriched abundant transcript 1 (lncRNA NEAT1) with microRNA (miR)-21, miR-124, and miR-125a, and their associations with disease risk, severity, and inflammatory cytokines of allergic rhinitis (AR).Totally 70 AR patients and 70 non-atopic obstructive snoring patients (as controls) were recruited. Inferior turbinate mucosa samples were collected from all participants for lncRNA NEAT1, its targets (miR-21, miR-124, and miR-125a), interleukin (IL)-4, IL-6, IL-10, and IL-17 detection via reverse transcription quantitative polymerase chain reaction. Disease severity of AR patients was assessed using individual nasal symptom score (INSS) and total nasal symptom score (TNSS).LncRNA NEAT1 was upregulated, while miR-21, miR-124, and miR-125a were downregulated in AR patients compared with controls. Additionally, lncRNA NEAT1, miR-21, and miR-125a displayed good values in differentiating AR patients from controls, while miR-124 could only slightly differentiate AR patients from controls. In AR patients, lncRNA NEAT1 was negatively associated with miR-21 and miR-125a, but not miR-124. However, in controls, no correlation of lncRNA NEAT1 with miR-21, miR-124, or miR-125a was observed. Furthermore, in AR patients, lncRNA NEAT1 was positively, while miR-21 and miR-125a was negatively associated with INSS (rhinorrhea, itching, congestion scores), TNSS and inflammatory cytokines; however, correlation of miR-124 with INSS, TNSS, and inflammatory cytokines was slight.LncRNA NEAT1 and its targets (miR-21 and miR-125a) present close correlations with disease risk, severity, and inflammation of AR, suggesting their potential as biomarkers for AR assessment., Competing Interests: The authors have no conflict of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

The water-gas shift (WGS) reaction is an industrially important source of pure hydrogen (H 2 ) at the expense of carbon monoxide and water 1,2 . This reaction is of interest for fuel-cell applications, but requires WGS catalysts that are durable and highly active at low temperatures 3 . Here we demonstrate that the structure (Pt 1 -Pt n )/α-MoC, where isolated platinum atoms (Pt 1 ) and subnanometre platinum clusters (Pt n ) are stabilized on α-molybdenum carbide (α-MoC), catalyses the WGS reaction even at 313 kelvin, with a hydrogen-production pathway involving direct carbon monoxide dissociation identified. We find that it is critical to crowd the α-MoC surface with Pt 1 and Pt n species, which prevents oxidation of the support that would cause catalyst deactivation, as seen with gold/α-MoC (ref. 4 ), and gives our system high stability and a high metal-normalized turnover number of 4,300,000 moles of hydrogen per mole of platinum. We anticipate that the strategy demonstrated here will be pivotal for the design of highly active and stable catalysts for effective activation of important molecules such as water and carbon monoxide for energy production.

Long-chain alcohols synthesis (LAS, C 5+ OH) from syngas provides a promising route for the conversion of coal/biomass/natural gas into high-value chemicals. Cu-Fe binary catalysts, with the merits of cost effectiveness and high CO conversion, have attracted considerable attention. Here we report a nano-construct of a Fe 5 C 2 -Cu interfacial catalyst derived from Cu 4 Fe 1 Mg 4 -layered double hydroxide (Cu 4 Fe 1 Mg 4 -LDH) precursor, i.e., Fe 5 C 2 clusters (~2 nm) are immobilized onto the surface of Cu nanoparticles (~25 nm). The interfacial catalyst exhibits a CO conversion of 53.2%, a selectivity of 14.8 mol% and a space time yield of 0.101 g g cat -1 h -1 for long-chain alcohols, with a surprisingly benign reaction pressure of 1 MPa. This catalytic performance, to the best of our knowledge, is comparable to the optimal level of Cu-Fe catalysts operated at much higher pressure (normally above 3 MPa).

The design of cheap, non-toxic, and earth-abundant transition metal catalysts for selective hydrogenation of alkynes remains a challenge in both industry and academia. Here, we report a new atomically dispersed copper (Cu) catalyst supported on a defective nanodiamond-graphene (ND@G), which exhibits excellent catalytic performance for the selective conversion of acetylene to ethylene, i.e., with high conversion (95%), high selectivity (98%), and good stability (for more than 60 h). The unique structural feature of the Cu atoms anchored over graphene through Cu-C bonds ensures the effective activation of acetylene and easy desorption of ethylene, which is the key for the outstanding activity and selectivity of the catalyst.

The mechanism on interfacial synergistic catalysis for supported metal catalysts has long been explored and investigated in several important heterogeneous catalytic processes (e.g., water-gas shift (WGS) reaction). The modulation of metal-support interactions imposes a substantial influence on activity and selectivity of catalytic reaction, as a result of the geometric/electronic structure of interfacial sites. Although great efforts have validated the key role of interfacial sites in WGS over metal catalysts supported on reducible oxides, direct evidence at the atomic level is lacking and the mechanism of interfacial synergistic catalysis is still ambiguous. Herein, Ni nanoparticles supported on TiO 2- x (denoted as Ni@TiO 2- x ) were fabricated via a structure topotactic transformation of NiTi-layered double hydroxide (NiTi-LDHs) precursor, which showed excellent catalytic performance for WGS reaction. In situ microscopy was carried out to reveal the partially encapsulated structure of Ni@TiO 2- x catalyst. A combination study including in situ and operando EXAFS, in situ DRIFTS spectra combined with TPSR measurements substantiates a new redox mechanism based on interfacial synergistic catalysis. Notably, interfacial Ni species (electron-enriched Ni δ- site) participates in the dissociation of H 2 O molecule to generate H 2 , accompanied by the oxidation of Ni δ- -O v -Ti 3+ (O v : oxygen vacancy) to Ni δ+ -O-Ti 4+ structure. Density functional theory calculations further verify that the interfacial sites of Ni@TiO 2- x catalyst serve as the optimal active site with the lowest activation energy barrier (∼0.35 eV) for water dissociation. This work provides a fundamental understanding on interfacial synergistic catalysis toward WGS reaction, which is constructive for the rational design and fabrication of high activity heterogeneous catalysts.

Objective: To investigate the dynamic changes in expression of programmed death (PD)-1, Toll-like receptor (TLR)3, and TLR4 on the surface of peripheral blood mononuclear cells (PBMCs) in patients with chronic hepatitis C (CHC) that occur in response to pegylated-interferon alpha-2a (peg-IFNalpha-2a) plus ribavirin (RBV) combination therapy, and to analyze the relation to achievement of sustained virological response (SVR). METHODS Twenty-three CHC patients and 10 healthy controls were enrolled in the study. All CHC patients underwent 48 weeks of combination therapy with peg-IFNalpha-2a (180 microg, subcutaneous injection, once weekly) plus RBV (15 microg/kg, oral, once daily). Total PBMCs were isolated from both groups (CHC patients at treatment week 0, 12, 24, and 48 and post-treatment week 24; controls at enrollment) and subjected to flow cytometric analysis of PD-1, TLR3, and TLR4 surface expression. In addition, serum levels of alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA levels were analyzed by enzymatic assay and the AmpliPrep/COBAS (Roche) nucleic acid amplification test, respectively. SVR was defined as undetectable levels of HCV RNA at post-treatment week 24. Intergroup differences were assessed by one-way ANOVA., Results: The expression ratios of PD-1, TLR4 and PD-1: TLR4 on PBMCs were significantly higher in CHC patients before therapy than in the healthy controls (45.20 +/- 7.12% vs. 16.82 +/- 4.13%, 58.45 +/- 15.13% vs. 21.09 +/- 2.89%, and 35.54 +/- 7.69% vs. 14.12 +/- 2.89%; all P < 0.05). In contrast, the expression ratios of TLR3 and PD-1:TLR3 were slightly, but not significantly, higher in CHC patients before therapy than in the healthy controls (P > 0.05). During the course of peg-IFNalpha-2a plus RBV combination therapy, the expression ratios of PD-1 and TLR4 on PBMCs showed a decreasing trend, while TLR3 expression showed an increasing trend. Furthermore, CHB patients who achieved SVR at post-treatment week 24 had a significantly different expression ratio of PD-1 and TLR3 than those who did not achieve SVR (P < 0.05)., Conclusion: Surface expression of PD-1, TLR4, and PD-1:TLR4 is up-regulated in the total PBMCs of CHC patients. Peg-IFNalpha-2a plus RBV treatment-induced suppression of HCV replication results in a significant reduction in PD-1 and TLR4 expression on the surface of PBMCs, but a remarkably elevated level of TLR3 expression. The dynamic change in PD-1 and TLR3 expression on PBMCs that occurs during antiviral therapy may be related to achievement of SVR.

Objective: To observe the expression variations and influencing factors of programmed death one (PD-1) and DNA demethylation of PD-1 promoter on peripheral blood mononuclear cells (PBMCs) in chronic hepatitis B (CHB) patients and further investigate the relationship between the demethylation pattern of PD-1 gene in promoter region and the PD-1 expression on PBMC in CHB patients., Methods: A total of 162 subjects, including 144 CHB patients and 18 healthy blood donors, were enrolled. The expression of PD-1 on PBMCs was detected by flow cytometry. And the serum HBV markers, HBV DNA load and liver function were also measured. DNA of PBMCs was treated with sodium bisulfite; the PD-1 promoter fragments were amplified by polymerase chain reaction (PCR) and then transformed into Escherichia coli. Positive clones were selected for sequencing and the methylation status of fragments of PD-1 promoter was examined., Results: With the PD-1 expression in normal controls (10.8% ± 4.4%) as a baseline level, the expression of PD-1 in CHB patients significantly increased. In CHB patients, the serum expression of PD-1 in PBMCs from patients with positive HBeAg (27.1% ± 18.4%) was much higher than that from those with negative HBeAg (19.6% ± 15.6%). And the expression level of PD-1 was not correlated with serum HBV DNA load and serum level of alanine aminotransferase. The results of bisulfite genomic sequencing showed that demethylation probability of some CG points in PD-1 promoter region (-601, -553, -538, -483, -463, -317 bp) were significantly correlated with PD-1 expression level (P < 0.05)., Conclusion: The demethylation pattern of PD-1 gene in promoter region is associated with the PD-1 expression on PBMC in CHB patients.

Objective: To optimize the aqueous two-phase extraction and separation technology of flavonoids from the leaves of Eucommia ulmoides., Methods: The system was prepared by dissolving suitable amounis of polyethylene glycol 4000 (PEG4000) and dextran 40000 ( D40) in aqueous solution. Phase map of the system, the mass fraction of PEG4000 and D40, the effects of amount of added sample, pH value and temperature on target compounds were investigated systematically., Results: The optimum extraction conditions were PEG4000 11%, N40 8%, 8 g sample which contains 6.85% of flavonoids, temperature 60 t and pH value 8. The highest extraction rate could reach to 75.82%., Conclusion: This method has the advantages of mild conditions, solvent-free residues and less time-consumed, and the obvious efficiency in single-stage separation and purification of flavonoids.

This paper adopt the high voltage pulsing microcapsule shaping device to produce microcapsules. Through processing the experiment on microcapsule production by changing the voltage, frequency, pulse width and pushing velocity, we could get the parameters related with the controlling of the diameter, shape and homogeneous degree. It is concluded that the size of microcapsules is mainly influenced by the voltage. The diameter of microcapsules decreases as the voltage increases. The homogeneous degree is largely influenced by the frequency. The homogeneous degree turns to be better when the frequency increases. The diameter and homogeneous degree of the microcapsules are also influence by the pulse width that should not be too large, a quarter to one half of the cycle will be the best.

The absorption spectroscopic determination of aucubin by condensation with p-dimethylaminobenzaldehyde was optimized in this paper. A high sensitive method was established and the linearity range of the method was from 4.5 to 45 microg x mL(-1). The influences of the factors, such as the dosage of coloring agent, reaction time, heating temperature and the dose of acid etc., on the system were studied. And the result indicated that all of the factors had obvious effects on the system. The method has been applied to determining the content of aucubin in the extract of Eucommia olive with satisfactory results.

Objective: To study the optimum technology of extracting bioactive component named geniposidic acid in Eucommia Ulmiodes by orthogonal test., Method: An orthogonal test table L16(4(5)) was used with the factors of extracting time, temperature, times, ethanol consistency and the ratio of solid to liquid. The content of geniposideic acid was determined by RP-HPLC., Result: The optimum technology was: temperature 50 degrees C, time 1 h, once, consistency 80%, and the ratio of solid and liquid 1:12. Under the condition, the best material of Eucommia Ulmiodes for extracting geniposidic acid was chosen., Conclusion: The technology can provide some theoretic advice for industry.