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This work provides a beneficial prototype for jointly modulating 2D/2D heterostructure, internal electric field, and SPR effect in Au/ZIS/WO3system, which exhibits outstanding H2evolution activity from seawater splitting under visible light.

Interface engineering in hybrid plasmonic metal/semiconductor heterostructures is an efficient approach to enhance the catalytic performance of photocatalysts and photoelectrochemical cells in harvesting and converting sunlight, especially in the range of visible light. Plasmon-induced hot electron injection plays a crucial role in the transfer of plasmonic energy from a plasmonic metal to semiconductor in a plasmonic metal/semiconductor system. Herein, the efficient injection and utilization of hot electrons are achieved by fabrication of a Au@ZnIn2S4/Ti3C2(Au@ZIS/Ti3C2) system, in which the core–shell Au@ZIS nanoparticles with well-defined interfaces are anchored on the 2D Ti3C2surface. The core–shell Au@ZIS nanostructure is first constructed by a cation exchange reaction method. The well-defined interface of the Au core and ZIS shell optimizes the electron transfer pathway and greatly promotes the extraction of hot electrons from Au to ZIS. Furthermore, the electrons concentrated on ZIS can be further transferred to Ti3C2owing to its excellent electron mobility and conductivity, leading to highly efficient separation and transfer of electrons through a two-step transfer process. The activities of photoelectrochemical (PEC) seawater splitting demonstrate that the integration of Au and ZIS into an optimized core–shell structure and its further modification by Ti3C2results in a drastic improvement in PEC activity. Therefore, Au@ZIS/Ti3C2shows the highest photocurrent density and smallest charge transfer resistance among various samples, accompanied by 6.5 and 10.8 orders of enhancement in PEC H2evolution compared to reference samples of ZIS/Ti3C2and Au/Ti3C2. Elaborate design and construction of core–shell plasmonic metal@semiconductor nanostructure with a well-defined interface and 2D MXene support would provide a feasible and promising method to enhance the performance of PEC seawater splitting.

Background The mechanism by which human cytomegalovirus (HCMV) stimulates oncogenesis is unclear. Because cellular immortalization and transformation require telomerase activation by expression of the telomerase reverse transcriptase (hTERT) gene, we examined the role of HCMV in telomerase activation. Methods Normal human diploid fibroblasts (HDFs) and human malignant glioma (MG) cell lines were infected with HCMV or transfected with expression vectors encoding HCMV immediate early (IE) antigen 72 or 86. hTERT expression and promoter activity and telomerase activity were evaluated using reverse transcription-polymerase chain reaction, a luciferase reporter assay, and a telomeric repeat amplification protocol, respectively, hTERT promoter occupancy by the transcription factor Sp1, IE antigens, and histone deacetylases (HDACs) was assessed by chromatin immunoprecipitation, hTERT and IE protein expression in human primary glioblastoma multiforme (GBM) was determined immunohistochemically. All statistical tests were two-sided. Results In telomerase and hTERT-negative HDFs, HCMV infection induced constitutive hTERT expression and telomerase activation. The hTERT promoter activity in HDFs and MG cell lines was statistically significantly enhanced by HCMV in a dose-dependent manner (mean luciferase activity [arbitrary units] in control HDFs and in HDFs infected with HCMV at multiplicities of infection [MOIs] of 0.1 = 6 and 521, respectively, difference = 515, 95% CI = 178 to 850; mean activity at MOI of 1 and 10 = 8828 and 59923, respectively; P < .001 comparing control with HCMV-infected cells at all MOIs). Ectopic expression of HCMV IE-72 protein also stimulated hTERT promoter activity in HDFs. HCMV-mediated transactivation of the hTERT gene was dependent on the presence of Sp1-binding sites in the hTERT promoter and was accompanied by increases in Sp1 binding, acetylation of histone H3, and a reduction in HDAC binding at the core promoter. In specimens of GBM, HCMV IE and hTERT proteins were colocalized in malignant cells and their levels paralleled each other. Conclusions HCMV activates telomerase in both HDFs and malignant cells. These findings begin to reveal a novel mechanism by which HCMV infection may be linked to or modulate oncogenesis through telomerase activation.

The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to valuable chemicals is an efficient way to upgrade biomass molecules and replace traditional catalytic synthesis. It is crucial to develop efficient and low-cost earth-abundant electrocatalysts to enhance catalytic performance of HMF oxidation. Herein, a new type of two-dimensional (2D) hybrid arrays consisting of NiFe layered double hydroxides (LDH) nanosheets and bimetallic sulfide (NiFeS) is constructed viainterface engineering for efficient electrocatalytic oxidation of HMF to 2,5-furandicarboxylic acid (FDCA). The preparation process of 2D NiFe LDH/NiFeS with ultrathin heterostructure involves in anchoring a Co-based metal-organic framework (Co MOF) as template onto the carbon cloth (CC) via in-situgrowth, formation of NiFe LDH on the surface of Co MOF and subsequent partial sulfidation. The electrocatalyst of NiFe LDH/NiFeS exhibits outstanding performance towards HMF oxidation, about 98.5% yield for FDCA and 97.2% Faraday efficiency (FE) in the alkaline electrolyte with 10 mmol/L HMF, as well as excellent stability retaining 90.1% FE for FDCA after six cycles test. Moreover, even at an HMF concentration of 100 mmol/L, the yield and FE for FDCA remain high at 83.6% and 93.6%, respectively. These findings highlight that 2D heterostructure containing abundant interfaces between NiFe LDH nanosheets and NiFeS can enhance the intrinsic activity of LDH and thus promote the oxidation reaction kinetics. Additionally, the synergistic effect of the bimetallic NiFe compounds also improved the selectivity of HMF conversion to FDCA. Our present work demonstrates that constructing 2D ultrathin heterostructure of NiFe LDH/NiFeS is a facile strategy viainterface engineering to enhance the intrinsic activity of LDH electrocatalysts, which would open new avenues toward low-cost and advanced 2D nanocatalysts for sustainable energy conversion and electrochemical valorization of biomass derivatives.

Poly(styrene-co-maleic anhydride)s (SMAs) with different compositions and molecular weight were synthesized through the reversible addition–fragmentation chain transfer polymerization technique. SMAs were converted to poly(styrene-co-octadecyl maleimide)s (SNODMIs) by amidation with octadecyl amine and subsequent imidization. SNODMIs with octadecyl branches were evaluated as flow improvers in the model crude oil with a high content of asphaltenes. The effects of molecular structures, including molecular weight, branch content, and imidization degree, on the effectiveness of SNODMI in reducing the viscosity and yield stress and improving the morphologies of asphaltene particles were thoroughly investigated using a rotational rheometer with parallel plate geometry and a polarizing microscope with a hot stage, respectively. It has been found that efficacy of SNODMI in reducing the viscosity and yield stress of the model crude oil increases with an increasing branch content of SNODMI. (alt)SNODMI with the highest branch content, approximately 45 mol %, achieved the best performance. Too high or too low molecular weight is not beneficial for SNODMI to improve the flow ability of the model crude oil. The appropriate molecular weight (Mn= 3500 Da) is required to achieve the optimal effectiveness. The optimal imidization degree of SNODMI is 100% and is independent of the branch content. The addition of SNODMI in a real crude oil has reduced the viscosity and yield stress by more than 90%.

Hot water droplet and oils induced air cushion failure, intensively used fluorine-containing chemicals, tedious preparation process, etc. are the main bottlenecks of the current artificially fabricated superhydrophobic materials, restricting their large-scale production and real-world applications. Herein, a facile, scalable, fluorine-free spray-coating strategy was employed to achieve superhydrophobic and superoleophobic polymerized organosilanes/Al 2 O 3 nanoparticles (POS/Al 2 O 3 NPs) coatings. The POS/Al 2 O 3 NPs coating was achieved through hydrolytic condensation of tetraethyl orthoilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS) in the presence of Al 2 O 3 NPs. A variety of analytical techniques including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray photoelectron spectroscopy (EDS) were used to investigate the fabricated coatings. The POS/Al 2 O 3 NPs coating features high contact angle (>158°) and low sliding angle (<5°) for water, glycerol, and ethylene glycol droplets with different surface tensions, verifying both superhydrophobic and superoleophobic properties. Moreover, the coatings present extremely low surface adhesion force, excellent liquid-driven self-cleaning ability, and hot water repellency. The superamphiphobic POS/Al 2 O 3 NPs coating exhibits promising applications in various fields including self-cleaning, corrosion resistance, and preventing scald as this strategy is applicable on various substrates. [ABSTRACT FROM AUTHOR]

A vanadium redox flow battery (VRFB) represents the most commercially advanced and mature technology among redox flow batteries presently available. However, the catalytic activity of the original electrode material significantly hinders the energy efficiency of the vanadium ion redox reactions. Therefore, improving the electrodes is imperative to enhance the performance of the battery. VRFB commercialization is facilitated by the utilization of bifunctional electrodes acquired through in situmodification techniques. This approach enhances the performance of both the positive and negative electrodes, thereby increasing the efficiency of the battery. This study provides a summary of research concerning bifunctional electrodes acquired through in situmodification, including acid treatment, electrochemical treatment, heat treatment, and some novel methods. Furthermore, the application and challenges associated with bifunctional electrodes in VRFB are also outlined. This review concludes with a perspective on the future trajectory of VRFB development, elucidating the direction of its commercial advancement.

Electrochemical oxidation has attracted vast interest as a promising alternative to traditional chemical processes in fine chemical synthesis owing to its fast and sustainable features. An electrocatalytic membrane reactor (ECMR) with a three-dimensional (3D) electrode has been successfully designed for the selective oxidation of alcohols with high current efficiency to the corresponding acids or ketones. The anode electrode was fabricated by the in situloading of one-dimensional (1D) Co3O4nanowires (NWs) on the conductive porous Ti membrane (Co3O4NWs/Ti) viathe combination of a facile hydrothermal synthesis and subsequent thermal treatment. The electrocatalytic oxidation (ECO) results of alcohols exhibited superior catalytic performance with a higher current efficiency on the Co3O4NWs/Ti membrane compared with those of Co3O4nanoparticles on the Ti membrane (Co3O4NPs/Ti). Even under low reaction temperatures such as 0 °C, it still displayed a very high ECO activity for alcohol oxidation in the ECMR. For example, >99% conversion and 92% selectivity toward benzoic acid were obtained for the benzyl alcohol electrooxidation. The electrode is particularly effective for the cyclohexanol oxidation, and a selectivity of >99% to cyclohexanone was achieved at 0 °C, higher than most reported noble-metal catalysts under the aerobic reaction conditions. The extraordinary electrocatalytic performance of the 3D Co3O4NWs/Ti membrane electrode demonstrates the significant influence of morphology effect and engineering interfaces in membrane electrodes on the electrocatalytic activity and charge transfer process of nanocatalysts. Our results propose that similar membrane electrodes serve as versatile platforms for the applications of 1D nanomaterials, porous electrodes, and ECMRs.

The purpose of this study is to develop a high-energy neutron shielding material applied in proton therapy environment. Composite shielding material consisting of 10.00 wt% boron carbide particles (B4C), 13.64 wt% surface-modified cross-linked polyethylene (PE), and 76.36 wt% tungsten particles were fabricated by hot-pressure sintering method, where the optimal ratio of the composite is determined by the shielding effect under the neutron field generated in typical proton therapy environment. The results of Differential Scanning Calorimetry measurements (DSC) and tensile experiment show that the composite has good thermal and mechanical properties. In addition, the high energy-neutron shielding performance of the developed material was evaluated using cyclotron proton accelerator with 100 MeV proton. The simulation shows a 99.99% decrease in fast neutron injection after 44 cm shielding, and the experiment result show a 99.70% decrease. Finally, the shielding effect of replacing part of the shielding material of the proton therapy hall with the developed material was simulated, and the results showed that the total neutron injection decreased to 0.99‰ and the neutron dose reduced to 1.10‰ before the enhanced shielding. In summary, the developed material is expected to serve as a shielding enhancement material in the proton therapy environment.

AbstractA methodology for designing a Bonner sphere spectrometer was proposed based on the singular value decomposition (SVD) and information entropy theory. First, features of Bonner spheres were classified based on SVD, and then, the rationality of the selected spheres was analyzed. Second, the information entropy is used as the quantitative evaluation standard; combined with the unfolding method, the contribution of each Bonner sphere on the information entropy of the unfolded spectra was quantitatively analyzed. The spheres that have high influence on the information entropy of solution spectra can be identified, and then, the information entropy variation of the solution spectra can be suppressed by reducing the count fluctuation of these spheres. According to the proposed method, an optimized spectrometer was developed and applied to measuring 252Cf spectra.

Photosystem II (PSII) is a multisubunit pigment–protein complex and catalyses light-induced water oxidation, leading to the conversion of light energy into chemical energy and the release of dioxygen. We analysed the structures of two Psb28-bound PSII intermediates, Psb28–RC47 and Psb28–PSII, purified from a psbV-deletion strain of the thermophilic cyanobacterium Thermosynechococcus vulcanus, using cryo-electron microscopy. Both Psb28–RC47 and Psb28–PSII bind one Psb28, one Tsl0063 and an unknown subunit. Psb28 is located at the cytoplasmic surface of PSII and interacts with D1, D2 and CP47, whereas Tsl0063 is a transmembrane subunit and binds at the side of CP47/PsbH. Substantial structural perturbations are observed at the acceptor side, which result in conformational changes of the quinone (QB) and non-haem iron binding sites and thus may protect PSII from photodamage during assembly. These results provide a solid structural basis for understanding the assembly process of native PSII.

During the course of studying silicon-containing diblock copolymers, it was discovered that poly(3,5-di(trimethylsilyl)styrene)-block-poly(3,4-methylenedioxystyrene) (PDTMSS-b-PMDOS) showed very unusual thermal properties. The material can be recovered as a free-flowing powder despite heating above 250 °C. To better understand this behavior, homopolymers of the 3,5-disubstituted styrenes, poly(3,5-di(trimethylsilyl)styrene) (PDTMSS) and poly(3,5-di-tert-butylstyrene) (PDtBS), were prepared. These polymers are soluble in common organic solvents and formed clear, glassy thin films upon spin coating. These homopolymers were studied by differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS), dynamic mechanical analysis (DMA), and temperature-programmed ellipsometry. These experiments document the lack of a conventional glass transition in these materials below their decomposition temperature. A series of statistical copolymers of PDTMSS and PDtBS with styrene was synthesized and studied by DSC in an attempt to establish the Tgof the homopolymers by model-based extrapolation.

A series of poly(styrene-co-octadecyl maleimide) (SNODMI) with various molecular structures were prepared through RAFT polymerization and subsequent modification with amine. The obtained SNODMIs were applied in the model crude oil with a high content of asphaltenes (3 wt %) to stabilize the asphaltenes particles, which were precipitated by adding n-heptane. The results indicate that SNODMI is a highly effective asphaltene stabilizer and its molecular structures play a pivotal role in determining its performance. With increasing the octadecyl branch content of the SNODMIs, the stabilizing performance is improved. The alternative structure with the highest branch content achieves the best performance. The appropriate molecular weight of the copolymer (Mn = 3500 Da) is required to optimally stabilize asphaltenes. The optimal imidization degree of SNODMI varies with the branch content. For SNODMI with a lower branch content (10.37 mol %), the stabilizing performance increases with the decrease in the imidization degree and samples without any imidization shows the best performance. For SNODMI with a higher branch content (20.92 or 45.26 mol %), an appropriate imidization degree (64.31 or 66.10%) shows the highest stabilizing efficacy for asphaltenes.

Directed self-assembly (DSA) of high-χ block copolymer thin films is a promising approach for nanofabrication of features with length scale below 10 nm. Recent work has highlighted that kinetics are of crucial importance in determining whether a block copolymer film can self-assemble into a defect-free ordered state. In this work, different strategies for improving the rate of defect annihilation in the DSA of a silicon-containing, high-χ block copolymer film were explored. Chemo-epitaxial DSA of poly(4-methoxystyrene-block-4-trimethylsilylstyrene) with 5× density multiplication was implemented on 300 mm wafers by using production level nanofabrication tools, and the influence of different processes and material parameters on dislocation defect density was studied. It was observed that only at sufficiently low χNcan the block copolymer assemble into well-aligned patterns within a practical time frame. In addition, there is a clear correlation between the rate of the lamellar grain coarsening in unguided self-assembly and the rate of dislocation annihilation in DSA. For a fixed chemical pattern, the density of kinetically trapped dislocation defects can be predicted by measuring the correlation length of the unguided self-assembly under the same process conditions. This learning enables more efficient screening of block copolymers and annealing conditions by rapid analysis of block copolymer films that were allowed to self-assemble into unguided (commonly termed fingerprint) patterns.

AbstractOne key goal of heterogeneous catalysis study is to understand the correlation between the catalyst structure and its corresponding catalytic activity. In this review, we focus on recent strategies to synthesize well-defined Fischer-Tropsch synthesis (FTS) nanostructured catalysts and their catalytic performance in FTS. The development of those promising catalysts highlights the potentials of nanostructured materials to unravel the complex and dynamic reaction mechanism, particularly under the in situreaction conditions. The crucial factors associated with the catalyst compositions and structures and their effects on the FTS activities are discussed with an emphasis on the role of theoretical modeling and experimental results.

The article presents a study on the delamination behavior of an organic coating on metallic structures. Topics include the concept of stray current density (CD), the use of graphite electrodes, soil, and a direct current (DC) power supply, and the proportional relationship between the delaminated area and delamination time. It also discusses the impact of inadequate adhesion on metallic corrosion and the effects of hydrogen and hydroxyl ions on stray current delamination of an organic coating.

We employed 29Si and 27Al (3Q) magic-angle spinning (MAS) NMR spectroscopy and density functional theory/molecular mechanics (DFT/MM) calculations to investigate the effect of Al/Si substitutions and the presence of silanol nests on the 29Si and 27Al NMR parameters as well as the local geometry of SiO4and AlO4−tetrahedra of the nearest and next-nearest neighboring Si and Al atoms. The silicon-rich zeolite of the chabazite structure (Si/Al 38) was chosen for this study as a representative model of silicon-rich zeolites since it exhibits a low number of distinguishable T sites. Our computational results show the following: (I) Al atoms can occupy three different crystallographic T sites in the framework of chabazite (Si/Al 38). This result is in agreement with two observed 27Al NMR resonances. (II) An Al/Si substitution causes a downshift of the 29Si chemical shift of the nearest neighboring Siatoms (Al−O−Si) by 4−11 ppm. (III) The effect of a more distant Al/Si substitution (Al−O−Si−O−Si) is significantly less pronounced (downshift up to 2 ppm). (IV) An Al/Si substitution (Al−O−Si−O−Al) leads to larger 27Al isotropic chemical shifts of the next-nearest neighboring Alatoms by up to 3 ppm. (V) The presence of a silanol “nest” (vacant T site) as a nearest (H−O−Si) and next-nearest (H−O−Si−O−Si) neighbor is responsible for a systematic downshift of the 29Si chemical shift of Si by 11−16 ppm and by 0−1 ppm, respectively. (VI) There is no systematic effect of a silanol “nest” as a next-nearest neighbor (H−O−Si−O−Al) on the 27Al isotropic chemical shift of Al as its values are smaller for some H−O−Si−O−Alsequences (up to −3.6 ppm) and greater for others (up to +2.9 ppm). (VII) Al atoms present in hypothetical Al−O−Al sequences would have their 27Al isotropic chemical shifts larger by 7−9 ppm than single Al atoms. Our predictions of NMR parameters using the quantum mechanics/interatomic potential functions approach and our bare zeolite framework model are in good agreement with the available experiments.

H-SSZ-13 (CHA)and H-UTM-1 (MTF) zeolites have been synthesized, characterized, and employed as catalysts for the methanol-to-olefin (MTO) reaction. Both zeolites have eight-membered rings, and their structures and acidities are characterized by 27Al magic-angle spinning (MAS) NMR, NH3−TPD (temperature-programmed desorption), and in-situ IR spectroscopy. In-situ IR spectroscopy indicates that methanol is efficiently activated on the Brönsted acid sites of both zeolites. At 673 K, the methanol is quantitatively converted to hydrocarbons, mainly ethene and propene, over H-SSZ-13, whereas H-UTM-1 only initially gives a small amount of alkenes, the main product being dimethyl ether. It is proposed that the limited space in the cages of the MTF zeolite prevents formation of intermediate polymethylbenzenes and thereby also formation of hydrocarbons, whereas the cage size in the CHA type zeolite, which is active, is large enough to accommodate polymethylbenzenes.

The acid properties of MoHMCM-22 catalyst, which is the precursor form of the working catalyst for methane aromatization reaction, and the synergic effect between Mo species and acid sites were studied and characterized by various characterization techniques. It is concluded that Brønsted and Lewis acidities of HMCM-22 are modified due to the introduction of molybdenum. We suggest a monomer of Mo species is formed by the exchange of Mo species with the Brønsted acid sites. On the other hand, coordinate unsaturated sites CUS are suggested to be responsible for the formation of newly detected Lewis acid sites. Computer modelling is established and coupling with experimental results, it is then speculated that the effective activation of methane is properly accomplished on Mo species accommodated in the 12 MR supercages of MCM-22 zeolite whereas the Brønsted acid sites in the same channel system play a key role for the formation of benzene. A much more pronounced volcano-typed reactivity curve of the MoHMCM-22 catalysts, as compared with that of the MoHZSM-5, with respect to Mo loading is found and this can be well understood due to the unique channel structure of MCM-22 zeolite and synergic effect between Mo species and acid sites.