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Zeolites, the most technically important crystalline microporous materials, are indispensable cornerstones of chemical engineering because of their remarkable catalytic properties and adsorption capabilities. Numerous studies have demonstrated that the hierarchical engineering of zeolites can maximize accessible active sites and improve mass transport, which significantly decreases the internal diffusion limits to achieve the desired performance. However, the construction of hierarchical zeolites with ordered alignments and size-controlled substructures in a convenient way is highly challenging. Herein, we develop a facile procedure using two common structure-directing agents, tetrapropylammonium hydroxide (TPAOH) and tetraethylammonium hydroxide (TEAOH), to synthesize hierarchically aligned ZSM-5 (Hie-ZSM-5) crystals with a -axis alignment substructures of controllable size. The control of the substructure size (α) in the range of 10-60 nm and the corresponding similarity ( r = α/β, where β is the size of Hie-ZSM-5) ranging from 0.004 to 0.033 can be tuned by varying the Si/Al ratios (40-120). A systematic investigation of the overall crystallization process, using time-dependent XRD, SEM, TEM, and solid-state magic-angle spinning NMR ( 13 C, 27 Al, 29 Si) methods, enable us to construct a solid mechanism for the generation of Hie-ZSM-5. Most importantly, directional transport in the unique structures of Hie-ZSM-5 efficiently enhances mass diffusion, as well as catalytic activity and stability. These findings improve our understanding of the zeolite crystallization process and inspire novel methods for the rational design of hierarchical zeolites.

Crystalline zeolites have been proven to be excellent supports for confining subnanometric metal catalysts to boost the propane dehydrogenation (PDH) reaction. However, the introduced metallic species may suffer from severe sintering and limited stability during the catalytic process, especially when utilizing an industrial impregnation method for metal incorporation. In this study, we developed a new type of support based on amorphous protozeolite (PZ), taking advantage of its adjustable silanol chemistry and zeolitic microporous characteristic for stabilizing atomically dispersed PtSn catalyst via a simple, cost-effective coimpregnation process. The combination of X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy under CO atmosphere, and density functional theory calculations confirmed the formation of highly dispersed active Pt δ+ -O x -Sn species in PtSn/PZ. The PtSn/PZ catalyst exhibited a high propane conversion of 45.4% and a high propylene selectivity of 99% (WHSV= 3.6 h -1 , 550 °C), with a high apparent rate coefficient of 565 mol C 3 H 6 ·g Pt -1 ·h -1 ·bar -1 at a high WHSV of 108 h -1 -O δ+ -O x -Sn sites to PtSn alloy with decreasing silanol density of supports. This work provides a general strategy using silanol-rich amorphous protozeolite as support for stabilizing various metal catalysts by the simple impregnation method and also offers an effective way for fine tailoring the chemical state of metallic species via a silanol-engineered approach.

Creation of intrapenetrated mesopores with open highway from external surface into the interior of zeolite crystals are highly desirable that can significantly improve the molecular transport and active sites accessibility of microporous zeolites to afford enhanced catalytic properties. Here, different from traditional zeolite-seeded methods that generally produced isolated mesopores in zeolites, nanosized amorphous protozeolites with embryo structure of zeolites were used as seeds for the construction of single-crystalline hierarchical ZSM-5 zeolites with intrapenetrated mesopores (mesopore volume of 0.51 cm 3  g -1 ) and highly complete framework. In this strategy, in contrast to the conventional synthesis, only a small amount of organic structure directing agents and a low crystallization temperature were adopted to promise the protozeolites as the dominant growth directing sites to induce crystallization. The protozeolite nanoseeds provided abundant nucleation sites for surrounding precursors to be crystallized, followed by oriented coalescence of crystallites resulting in the formation of intrapenetrated mesopores. The as-prepared hierarchical ZSM-5 zeolites exhibited ultra-long lifetime of 443.9 hours and a high propylene selectivity of 47.92 % at a WHSV of 2 h -1 in the methanol-to-propylene reaction. This work provides a facile protozeolite-seeded strategy for the synthesis of intrapenetrated hierarchical zeolites that are highly effective for catalytic applications., (© 2023 Wiley-VCH GmbH.)

The synthesis and application of three-dimensional (3D) mesoporous covalent-organic frameworks (COFs) are still to be developed. Herein, two mesoporous 3D COFs with an stp topology were synthesized in a highly crystalline form with aniline as the modulator. The chemical composition of these COFs was confirmed by Fourier transform infrared (FT-IR) and 13 C cross-polarization magic angle spinning nuclear magnetic resonance (NMR) spectroscopies. These 3D mesoporous COFs were highly crystalline and exhibited permanent porosity and good chemical stability in both aqueous and organic media. The space group and unit cell parameters of COF HFPTP-TAE were verified by powder X-ray diffraction (PXRD), small-angle X-ray scattering, and three-dimensional electron diffraction (3D ED). The appropriate pore size of the COF HFPTP-TAE facilitated the inclusion of enzyme lipase PS with a loading amount of 0.28 g g -1 . The lipase⊂HFPTP-TAE (⊂ refers to "include in") composite exhibited high catalytic activity, good thermal stability, and a wide range of solvent tolerance. Specifically, it could catalyze the alcoholysis of aspirin methyl ester (AME) with high catalytic efficiency. Oriented one-dimensional (1D) channel mesopores in HFPTP-TAE accommodated lipase, meanwhile preventing them from aggregation, while windows on the wall of the 1D channel favored molecular diffusion; thus, this COF-enzyme design outperformed its amorphous isomer, two-dimensional (2D) mesoporous COF, 3D mesoporous COF with limited crystallinity, and mesoporous silica as an enzyme host.

Zeolite nonclassical growth via particle attachment has been proposed for two decades, yet the attachment mechanism and kinetic regulation remain elusive. Here, nonclassical growth of an MFI -type zeolite has been achieved by using amorphous protozeolite (PZ) nanoparticles containing encapsulated TPA + templates and abundant silanols (Si-OH) as sole precursors under hydrothermal conditions. The silanol characteristics of the precursor were studied by two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) correlation spectroscopy, which were proven to play critical roles in determining precursor attachment behavior and crystal growth orientation. Under mechanical ball-milling or tablet-pressing process, pressure drove the fusion of spherical PZ into platelet-like integrated PZ (IPZ) coupled with transformations of external silanols from evenly distributed to curvature-dependent distributed and internal silanols from isolated to spatially proximate. Compared to isolated silanols, the spatially proximate silanols possessed a stronger correlation with TPA + , benefiting the formation of Si-O-Si bonds via silanol condensation. Subsequently, driven by minimization of surface energy, particle attachment of the platelet-like IPZ precursor preferentially occurred at high-curvature surfaces with high-density silanols, leading to anisotropic rates of nonclassical growth and thus the formation of high-aspect-ratio MFI -type zeolite nanosheets. Advanced electron microscopy provided direct evidence of attachment of amorphous IPZ precursors to crystalline intermediate surfaces along the c -axis direction with the formation of amorphous-crystalline interfaces, followed by interface elimination and structural evolution to a single-crystalline phase. Our findings not only unravel the zeolite nonclassical growth mechanism but also reveal the critical role of silanol chemistry in kinetic regulation, which is of great importance for pursuing a tailored zeolite synthesis.

Chemotherapy remains as the first-choice treatment option for triple-negative breast cancer (TNBC). However, the limited tumor penetration and low cellular internalization efficiency of current nanocarrier-based systems impede the access of anticancer drugs to TNBC with dense stroma and thereby greatly restricts clinical therapeutic efficacy, especially for TNBC bone metastasis. In this work, biomimetic head/hollow tail nanorobots were designed through a site-selective superassembly strategy. We show that nanorobots enable efficient remodeling of the dense tumor stromal microenvironments (TSM) for deep tumor penetration. Furthermore, the self-movement ability and spiky head markedly promote interfacial cellular uptake efficacy, transvascular extravasation, and intratumoral penetration. These nanorobots, which integrate deep tumor penetration, active cellular internalization, near-infrared (NIR) light-responsive release, and photothermal therapy capacities into a single nanodevice efficiently suppress tumor growth in a bone metastasis female mouse model of TNBC and also demonstrate potent antitumor efficacy in three different subcutaneous tumor models., (© 2023. The Author(s).)

This article focuses on the Na 2 O-Ga 2 O 3 -TiO 2 system, which is barely explored in the study of transparent conductive oxides (TCOs). Na x Ga 4+x Ti n-4-x O 2n-2 (n = 5, 6, and 7 and x ≈ 0.7-0.8) materials were characterized using neutron powder diffraction and aberration-corrected scanning transmission electron microscopy. Activation energy, as a function of different structures depending on tunnel size, shows a significant improvement in Na + ion conduction from hexagonal to octagonal tunnels. New insights into the relationship between the crystal structure and the transport properties of TCOs, which are crucial for the design and development of new optoelectronic devices, are provided.

A precise investigation of NbO has been carried out by advanced electron microscopy combined with powder and single crystal X-ray diffraction (XRD). The structure of pristine NbO has been determined as Pm-3 m space group (SG) with a = 4.211 Å and the positions of Nb and O at the 3c and 3d Wyckoff positions, respectively, which is consistent with previous report based on powder XRD data. Electron beams induced a structural transition, which was investigated and explained by combining electron diffraction and atomic-resolution imaging. The results revealed that the electron beam stimulated both Nb and O atom-migrations within each fcc sublattice, and that the final structure was SG Fm-3 m with a = 4.29 Å, Nb and O at the 4a and 4b with 75 % occupancy and same chemical composition. Antiphase planar defects were discovered in the pristine NbO and related to the structural transformation. Theoretical calculations performed by density functional theory (DFT) supported the experimental conclusions., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The rational design of a stable and catalytic carbon cathode is crucial for the development of rechargeable lithium-oxygen (LiO 2 ) batteries. An edge-site-free and topological-defect-rich graphene-based material is proposed as a pure carbon cathode that drastically improves LiO 2 battery performance, even in the absence of extra catalysts and mediators. The proposed graphene-based material is synthesized using the advanced template technique coupled with high-temperature annealing at 1800 °C. The material possesses an edge-site-free framework and mesoporosity, which is crucial to achieve excellent electrochemical stability and an ultra-large capacity (>6700 mAh g -1 ). Moreover, both experimental and theoretical structural characterization demonstrates the presence of a significant number of topological defects, which are non-hexagonal carbon rings in the graphene framework. In situ isotopic electrochemical mass spectrometry and theoretical calculations reveal the unique catalysis of topological defects in the formation of amorphous Li 2 O 2 , which may be decomposed at low potential (∼ 3.6 V versus Li/Li + ) and leads to improved cycle performance. Furthermore, a flexible electrode sheet that excludes organic binders exhibits an extremely long lifetime of up to 307 cycles (>1535 h), in the absence of solid or soluble catalysts. These findings may be used to design robust carbon cathodes for LiO 2 batteries., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Metastable noble metal nanocrystals may exhibit distinctive catalytic properties to address the sluggish kinetics of many important processes, including the hydrogen evolution reaction under alkaline conditions for water-electrolysis hydrogen production. However, the exploration of metastable noble metal nanocrystals is still in its infancy and suffers from a lack of sufficient synthesis and electronic engineering strategies to fully stimulate their potential in catalysis. In this paper, we report a synthesis of metastable hexagonal Pt nanostructures by coherent growth on 3d transition metal nanocrystals such as Ni without involving galvanic replacement reaction, which expands the frontier of the phase-replication synthesis. Unlike noble metal substrates, the 3d transition metal substrate owns more crystal phases and lower cost and endows the hexagonal Pt skin with substantial compressive strains and programmable charge density, making the electronic properties particularly preferred for the alkaline hydrogen evolution reaction. The energy barriers are greatly reduced, pushing the activity to 133 mA cm geo -2 and 17.4 mA μg Pt -1 at -70 mV with 1.5 µg of Pt in 1 M KOH. Our strategy paves the way for metastable noble metal catalysts with tailored electronic properties for highly efficient and cost-effective energy conversion., (© 2023. The Author(s).)

Conductive metal-organic frameworks ( c -MOFs) with outstanding electrical conductivities and high charge carrier mobilities are promising candidates for electronics and optoelectronics. However, the poor solubility of planar ligands greatly hinders the synthesis and widespread applications of c -MOFs. Nonplanar ligands with excellent solubility in organic solvents are ideal alternatives to construct c -MOFs. Herein, contorted hexabenzocoronene ( c -HBC) derivatives with good solubility are adopted to synthesize c -MOFs. Three c -MOFs ( c -HBC-6O-Cu, c -HBC-8O-Cu, and c -HBC-12O-Cu) with substantially different geometries and packing modes have been synthesized using three multitopic catechol-based c -HBC ligands with different symmetries and coordination numbers, respectively. With more metal coordination centers and increased charge transport pathways, c -HBC-12O-Cu exhibits the highest intrinsic electrical conductivity of 3.31 S m -1 . Time-resolved terahertz spectroscopy reveals high charge carrier mobilities in c -HBC-based c -MOFs, ranging from 38 to 64 cm 2 V -1 s -1 . This work provides a systematic and modular approach to fine-tune the structure and enrich the c -MOF family with excellent charge transport properties using nonplanar and highly soluble ligands.

Two-dimensional conductive metal-organic frameworks (2D c -MOFs) are an emerging class of promising porous materials with high crystallinity, tunable structures, and diverse functions. However, the limited topologies and difficulties in synthesizing suitable organic linkers remain a great challenge for 2D c -MOFs synthesis and applications. Herein, two layered 2D c -MOF polymorphs with either a rhombus structure ( sql -TBA-MOF) or kagome structure ( kgm -TBA-MOF) were directly constructed via in situ Scholl reaction and coordination chemistry from a flexible and nonplanar tetraphenylbenzene-based ligand (8OH-TPB) in a one-pot manner. Interestingly, the kgm -TBA-MOF comprising hexagonal and triangular dual pores exhibit higher conductivities of 1.65 × 10 -3 S/cm at 298 K and 3.33 × 10 -2 S/cm at 353 K than that of sql -TBA-MOF (4.48 × 10 -4 and 2.90 × 10 -3 S/cm, respectively). Moreover, the morphology and topology can be modulated via the addition of ammonium hydroxide as modulator. The present work provides a new pathway for design, synthesis, and topological regulation of 2D c -MOFs.

Incorporating hetero-metal-atom, e.g., titanium, into zeolite frameworks can enhance the catalytic activity and selectivity in oxidation reactions. However, the rational design of zeolites containing titanium at specific sites is difficult because the precise atomic structure during synthesis process remained unclear. Here, a titanosilicate with predictable titanium distribution was synthesized by mediating vacancies in a defective MSE-type zeolite precursor, based on a pre-designed synthetic route including modification of vacancies followed by titanium insertion, where electron microscopy (EM) plays a key role at each step resolving the atomic structure. Point defects including vacancies in the precursor and titanium incorporated into the vacancy-related positions have been directly observed. The results provide insights into the role of point defects in zeolites towards the rational synthesis of zeolites with desired microscopic arrangement of catalytically active sites., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Electron microscopy has been widely used in the structural analysis of proteins, pharmaceutical products, and various functional materials in the past decades. However, one fact is often overlooked that the crystal structure might be sensitive to external environments and response manners, which will bring uncertainty to the structure determination and structure-property correlation. Here, we report the atomic-level ab initio structure determinations of microcrystals by combining 3D electron diffraction (3D ED) and environmental transmission electron microscope (TEM). Environmental conditions, including cryo, heating, gas and liquid, have been successfully achieved using in situ holders to reveal the simuli-responsive structures of crystals. Remarkable structural changes have been directly resolved by 3D ED in one flexible metal-organic framework, MIL-53, owing to the response of framework to pressures, temperatures, guest molecules, etc., (© 2022. The Author(s).)

Charges on a metal nanoparticle are measured with precision by electron holography.

Chiral mesostructures exhibit distinctive twisting and helical hierarchical stacking ranging from atomic to micrometre scales with fascinating structural-chiral anisotropy properties. However, the detailed determination of their multilevel chirality remains challenging due to the limited information from spectroscopy, diffraction techniques, scanning electron microscopy and the two-dimensional projections in transmission electron microscopy. Herein, we report a general approach to determine chiral hierarchical mesostructures based on three-dimensional electron diffraction tomography (3D EDT), by which the structure can be solved synchronously according to the quantitative measurement of diffraction spot deformations and their arrangement in reciprocal space. This method was verified on two samples-chiral mesostructured nickel molybdate and chiral mesostructured tin dioxide-revealing hierarchical chiral structures that cannot be determined by conventional techniques. This approach provides more precise and comprehensive identification of the hierarchical mesostructures, which is expected to advance our understanding of structural-chiral anisotropy at the fundamental level., (© 2022. The Author(s).)

Hierarchical zeolites integrating intrinsic micropores with secondary meso- and/or macropores afford superior catalytic properties for enhanced mass transportation and more accessible active sites. The mesopores generated by using mesoporogens or framework etching are usually irregular with abundant defective sites and low hydrothermal stability. Here, using protozeolite nanoparticles as seeds, we succeeded in the synthesis of single-crystalline hierarchical ZSM-5 zeolites with hexagonal mesopores faceted by complete microporous frameworks. The protozeolites played a key role in the formation of faceted mesopores achieved via intraparticle ripening process. Thanks to the unique texture properties and more accessible acid sites at the open location, the as-prepared zeolites exhibited remarkedly long lifetime (18 h) and high propylene selectivity (52.7 %) with propylene/ethylene ratio of 3.64 in the methanol-to-propylene reaction (WHSV=12.5 h -1 ) compared to the counterparts., (© 2022 Wiley-VCH GmbH.)

Conventional separation technologies to separate valuable commodities are energy intensive, consuming 15% of the worldwide energy. Mixed-matrix membranes, combining processable polymers and selective adsorbents, offer the potential to deploy adsorbent distinct separation properties into processable matrix. We report the rational design and construction of a highly efficient, mixed-matrix metal-organic framework membrane based on three interlocked criteria: (i) a fluorinated metal-organic framework, AlFFIVE-1-Ni, as a molecular sieve adsorbent that selectively enhances hydrogen sulfide and carbon dioxide diffusion while excluding methane; (ii) tailoring crystal morphology into nanosheets with maximally exposed (001) facets; and (iii) in-plane alignment of (001) nanosheets in polymer matrix and attainment of [001]-oriented membrane. The membrane demonstrated exceptionally high hydrogen sulfide and carbon dioxide separation from natural gas under practical working conditions. This approach offers great potential to translate other key adsorbents into processable matrix.

Hydrogen evolution reaction (HER) through water splitting is a potential technology to realize the sustainable production of hydrogen, yet the tardy water dissociation and costly Pt-based catalysts inhibit its development. Here, a trapping-bonding strategy is proposed to realize the superassembly of surface-enriched Ru nanoclusters on a phytic acid modified nitrogen-doped carbon framework (denoted as NCPO-Ru NCs). The modified framework has a high affinity to metal cations and can trap plenty of Ru ions. The trapped Ru ions are mainly distributed on the surface of the framework and can form Ru nanoclusters at 50 °C with the synergistic effect of vacancies and phosphate groups. By adjusting the content of phytic acid, surface-enriched Ru nanoclusters with adjustable distribution and densities can be obtained. Benefiting from the adequate exposure of the active sites and dense distribution of ultrasmall Ru nanoclusters, the obtained NCPO-Ru NCs catalyst can effectively drive HER in alkaline electrolytes and show an activity (at overpotential of 50 mV) about 14.3 and 9.6 times higher than that of commercial Ru/C and Pt/C catalysts, respectively. Furthermore, the great performance in solar to hydrogen generation through water splitting provides more flexibility for wide applications of NCPO-Ru NCs.

From genetic and etiological studies, autoimmune mechanisms underlying schizophrenia are suspected; however, the details remain unclear. In this study, we describe autoantibodies against neural cell adhesion molecule (NCAM1) in patients with schizophrenia (5.4%, cell-based assay; 6.7%, ELISA) in a Japanese cohort (n = 223). Anti-NCAM1 autoantibody disrupts both NCAM1-NCAM1 and NCAM1-glial cell line-derived neurotrophic factor (GDNF) interactions. Furthermore, the anti-NCAM1 antibody purified from patients with schizophrenia interrupts NCAM1-Fyn interaction and inhibits phosphorylation of FAK, MEK1, and ERK1 when introduced into the cerebrospinal fluid of mice and also reduces the number of spines and synapses in frontal cortex. In addition, it induces schizophrenia-related behavior in mice, including deficient pre-pulse inhibition and cognitive impairment. In conclusion, anti-NCAM1 autoantibodies in patients with schizophrenia cause schizophrenia-related behavior and changes in synapses in mice. These antibodies may be a potential therapeutic target and serve as a biomarker to distinguish a small but treatable subgroup in heterogeneous patients with schizophrenia., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

Atomically dispersed catalysts are a new type of material in the field of catalysis science, yet their large-scale synthesis under mild conditions remains challenging. Here, a general synergistic capture-bonding superassembly strategy to obtain atomically dispersed Pt (Ru, Au, Pd, Ir, and Rh)-based catalysts on micropore-vacancy frameworks at a mild temperature of 60 °C is reported. The precise capture via narrow pores and the stable bonding of vacancies not only simplify the synthesis process of atomically dispersed catalysts but also realize their large-scale preparation at mild temperature. The prepared atomically dispersed Pt-based catalyst possesses a promising electrocatalytic activity for hydrogen evolution, showing an activity (at overpotential of 50 mV) about 21.4 and 20.8 times higher than that of commercial Pt/C catalyst in 1.0 M KOH and 0.5 M H 2 SO 4 , respectively. Besides, the extremely long operational stability of more than 100 h provides more potential for its practical application.

Hollow nanoparticles featuring tunable structures with spatial and chemical specificity are of fundamental interest. However, it remains a significant challenge to design and synthesize asymmetric nanoparticles with controllable topological hollow architecture. Here, a versatile kinetics-regulated cooperative polymerization induced interfacial selective superassembly strategy is demonstrated to construct a series of asymmetric hollow porous composites (AHPCs) with tunable diameters, architectures and components. The size and number of patches on Janus nanoparticles can be precisely manipulated by the precursor and catalyst content. Notably, AHPCs exhibit excellent photothermal conversion performance under the irradiation of a near infrared (NIR) laser. Thus, AHPCs are utilized as NIR light-triggered nanovehicles and cargos can be controllably released. In brief, this versatile superassembly approach offers a streamlined and powerful toolset to design diverse asymmetric hollow porous composites., (© 2022 Wiley-VCH GmbH.)

Herein, we report the adsorbate behavior in individual local pores of MIL-101, which is a metal-organic framework (MOF) with two heterogeneous mesopores and different metal sites, by combining adsorbate isotherms and in situ crystallography profiles. The in situ mapping shows that the substrate-adsorbate interaction affects the initial adsorption and pore condensation steps. The monolayer adsorption gradient changes greatly depending on the framework metal-adsorbate attraction force. Also, broad inflection points are found in adsorption isotherms, and the initial shape depends on the different metals. Besides, the capillary condensation at a pore draws adsorbates from other local pores. This leads to the local negative uptake behavior in individual pore isotherms. At higher pressure, they move to a larger space, whereas in a relatively low-pressure range the attraction force between the MOF framework and guest molecule influences the amount of rearranged guest molecules. Furthermore, the origin of the characteristic adsorption behavior based on the metals constituting the MOFs and the relative strength of substrate-adsorbate and adsorbate-adsorbate interactions are elucidated through the combined study of electron densities in pores, electron paramagnetic resonance spectroscopy spectra, and density functional theory and Monte Carlo simulations to uncover the previously veiled information on adsorption behavior.

For a better design of adsorbents, it is important to know the intermolecular interaction among adsorbates and host material, leading to improved guest selectivity and uptake capacity. In this study, we demonstrate the influence of the interaction among adsorbates and substrate, controlled by the pore environment and species of adsorbates, on the adsorption behaviour. We report the unique CO 2 adsorption behaviour of MOF-205 due to distinct pore geometry. The precise analysis through gas-adsorption crystallography with molecular simulation shows that capillary condensation of CO 2 in MOF-205 occurs preferentially in the large dodecahedral pore rather than the small tetrahedral pore, because the interaction of CO 2 with MOF-205 framework is weaker than that among CO 2 molecules, while Ar and N 2 are sequentially filled into two different pores of MOF-205 according to their size. Comparison of the materials with different pore environments reveals that the relative strength of the adsorbate-adsorbate and adsorbate-substrate interaction gives rise to different shapes of isotherms., (© 2021 Wiley-VCH GmbH.)

The objective of this study is to evaluate otitis media with effusion (OME) among patients with parapharyngeal tumor. We have experienced 82 parapharyngeal tumor cases and encountered 14 patients complaining of hearing loss due to OME as the initial symptom. These patients showed normal nasopharyngeal findings and the presence of tumor had been detected long time after the beginning of their hearing symptoms (4 months to 13 years: median 2.5 years). Six patients had undergone ventilation tube insertion on the affected ear, which may lead to delay in diagnosis. Pathological examination was performed in 76 of 82 patients. Among these 76 patients, 13 showed OME. Seven patients had malignant lesions, whereas 6 had benign lesions. Therefore, malignant lesions are prone to occur with OME and its relative risk was 2.26 (95% confidence intervals, 1.16-4.42). This difference was statistically significant ( P = .044, Fisher test). Otitis media with effusion is a very common disease and is well-known as a primary symptom of nasopharyngeal carcinoma. Therefore, nasopharyngeal observation is necessary for patients with intractable middle ear effusion. However, present 14 patients with OME showed normal nasopharyngeal findings and finally found after an imaging study. From our data, OME is an important but go-by symptom of parapharyngeal tumors. Imaging studies are potently useful for such patients with intractable OME.

2D conductive metal-organic frameworks (2D c-MOFs) are promising candidates for efficient electrocatalysts for the CO 2 reduction reaction (CO 2 RR). A nitrogen-rich tricycloquinazoline (TQ) based multitopic catechol ligand was used to coordinate with transition-metal ions (Cu 2+ and Ni 2+ ), which formed 2D graphene-like porous sheets: M 3 (HHTQ) 2 (M=Cu, Ni; HHTQ=2,3,7,8,12,13-Hexahydroxytricycloquinazoline). M 3 (HHTQ) 2 can be regarded as a single-atom catalyst where Cu or Ni centers are uniformly distributed in the hexagonal lattices. Cu 3 (HHTQ) 2 exhibited superior catalytic activity towards CO 2 RR in which CH 3 OH is the sole product. The Faradic efficiency of CH 3 OH reached up to 53.6 % at a small over-potential of -0.4 V. Cu 3 (HHTQ) 2 exhibited larger CO 2 adsorption energies and higher activities over the isostructural Ni 3 (HHTQ) 2 and the reported archetypical Cu 3 (HHTP) 2 . There is a strong dependence of both metal centers and the N-rich ligands on the electrocatalytic performance., (© 2021 Wiley-VCH GmbH.)

Zeolites are becoming more versatile in their chemical functions through rational design of their frameworks. Therefore, direct imaging of all atoms at the atomic scale, basic units (Si, Al, and O), heteroatoms in the framework, and extra-framework cations, is needed. TEM provides local information at the atomic level, but the serious problem of electron-beam damage needs to be overcome. Herein, all framework atoms, including oxygen and most of the extra-framework Na cations, are successfully observed in one of the most electron-beam-sensitive and lowest framework density zeolites, Na-LTA. Zeolite performance, for instance in catalysis, is highly dependent on the location of incorporated heteroatoms. Fe single atomic sites in the MFI framework have been imaged for the first time. The approach presented here, combining image analysis, electron diffraction, and DFT calculations, can provide essential structural keys for tuning catalytically active sites at the atomic level., (© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt-based catalysts usually suffer from short-term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand-protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt-Zn clusters inside silicalite-1 (S-1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6-54 h -1 and specific activity of propylene formation of 65.5 mol C 3 H 6  g Pt -1  h -1 (WHSV=108 h -1 ) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S-1-H catalyst even after 13000 min on stream (WHSV=3.6 h -1 ), affording an extremely low deactivation constant of 0.001 h -1 O 2 O 3 counterpart under the same conditions. We also show that the introduction of Cs + ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Zeolites are widely used in catalysis, gas separation, ion exchange, etc. due to their superior physicochemical properties, which are closely related to specific features of their framework structures. Although more than two hundred different framework types have been recognized, it is of great interest to explore from a crystallographic perspective, the atomic positions, surface terminations, pore connectivity and structural defects that deviate from the ideal framework structures, namely local structural modulation. In this article, we review different types of local modulations in zeolite frameworks using various techniques, especially electron microscopy (EM). The most recent advances in resolving structural information at the atomic level with aberration corrected EM are also presented, commencing a new era of gaining atomic structural information, not only for all tetrahedral atoms including point vacancies in framework but also for extra-framework cations and surface terminations., (© 2020 The Authors. Published by Wiley-VCH GmbH.)

Metal-organic frameworks (MOFs) 1-3 are known for their specific interactions with gas molecules 4,5 ; this, combined with their rich and ordered porosity, makes them promising candidates for the photocatalytic conversion of gas molecules to useful products 6 . However, attempts to use MOFs or MOF-based composites for CO 2 photoreduction 6-13 usually result in far lower CO 2 conversion efficiency than that obtained from state-of-the-art solid-state or molecular catalysts 14-18 , even when facilitated by sacrificial reagents. Here we create 'molecular compartments' inside MOF crystals by growing TiO 2 inside different pores of a chromium terephthalate-based MOF (MIL-101) and its derivatives. This allows for synergy between the light-absorbing/electron-generating TiO 2 units and the catalytic metal clusters in the backbones of MOFs, and therefore facilitates photocatalytic CO 2 reduction, concurrent with production of O 2 . An apparent quantum efficiency for CO 2 photoreduction of 11.3 per cent at a wavelength of 350 nanometres is observed in a composite that consists of 42 per cent TiO 2 in a MIL-101 derivative, namely, 42%-TiO 2 -in-MIL-101-Cr-NO 2 . TiO 2 units in one type of compartment in this composite are estimated to be 44 times more active than those in the other type, underlining the role of precise positioning of TiO 2 in this system.

Surface-sensitive information on a bulk sample can be obtained by using a low incident electron energy (low accelerating voltage/landing voltage) in a scanning electron microscope (SEM). However, topography and composition contrast obtained at low incident electron energies may not be intuitive and should be analyzed carefully. By combining an Auger electron spectrometer (AES) with a low incident electron energy SEM (LE-SEM), we investigated the SEM contrast carefully by separating the secondary electron (SE) and back-scattered electron (BSE) components with high accuracy. For this, we modified an AES to measure the electron energy in the range of 0–0.6 keV with a sample bias voltage of 0 to −0.3 keV. We could clearly observe reversed brightness of gold and carbon (graphite) in BSE images when the energy of the incident electrons was reduced to 0.2–0.3 keV. In addition, reflected electron energy spectroscopy (REELS) is known to be a tool for chemical state analysis of the sample. We demonstrated that it is possible to study the electron states of graphite, diamond, and graphene by acquiring low incident energy REELS spectra from their surfaces with the newly modified AES. This will be a new method for analyzing the electron states of local areas of a surface.

Objective: We aimed to clarify the burden of vertigo in patients' homes., Methods: This was a questionnaire survey among patients with vestibular vertigo. Four main questions were prepared. Q1: Where did you first notice vertigo? Q2: Where have you had the most difficulty with vertigo in your home? Q3: Where do you have difficulty at present? Q4: What household equipment have you used as a countermeasure to prevent further problems with vertigo?, Results: Sixty patients completed the questionnaire. Benign paroxysmal positional vertigo (BPPV) was most common among respondents, followed by Ménière's disease. Q1: Most patients with BPPV first noticed vertigo in the bedroom; patients with other diseases first noticed vertigo in the living room. Q2: Both groups previously had the most difficulty with vertigo in the same locations as in Q1; these differences were significant between Q1 and Q2. Q3: Both groups had the most difficulty on stairs. Q4: Handrails were the most often used equipment for vertigo in both groups. There was no significant difference between Q3 and Q4., Conclusion: Our data revealed that the locations of risks differ among patients with vestibular disorders. Handrails were considered the most important equipment to prevent problems with vertigo.

Defects within zeolites are crucially important for explaining their physicochemical behavior. The UTL zeolite, with a pillared layer structure, has been widely used in zeolite crystal engineering to assemble new structures from its layered structural units, but a fundamental understanding of its defect is lacking. Here, we report a newly synthesized UTL framework zeolite, UTL-DBU, with a commercially available superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a template. Its structure was determined by a combination of three-dimensional electron diffraction tomography and high-resolution (scanning) transmission electron microscopy. Using transmission electron microscopy, two types of defects, stacking disorder and edge dislocation-like planar defect, were discovered. On the basis of the analysis of the electron diffraction and imaging, the layer stacking sequence together with the structural and mathematical models of the microtwinning was successfully built up. Unraveling these defects will provide new insights into the rational design of targeted zeolites utilizing UTL .

Bicontinuous cubic structures in soft matter consist of two intertwining labyrinths separated by a partitioning layer. Combining experiments, numerical modelling and techniques in differential geometry, we investigate twinning defects in bicontinuous cubic structures. We first demonstrate that a twin boundary is most likely to occur at a plane that cuts the partitioning layer almost perpendicularly, so that the perturbation caused by twinning remains minimal. This principle can be used as a criterion to identify potential twin boundaries, as demonstrated through detailed investigations of mesoporous silica crystals characterized by diamond and gyroid surfaces. We then discuss that a twin boundary can result from a stacking fault in the arrangement of inter-lamellar attachments at an early stage of structure formation. It is further shown that enhanced curvature fluctuations near the twin boundary would cost energy because of geometrical frustration, which would be eased by a crystal distortion that is experimentally observed., (© Han et al. 2020.)

A conjugated copper(II) catecholate based metal-organic framework (namely Cu-DBC) was prepared using a D 2 -symmetric redox-active ligand in a copper bis(dihydroxy) coordination geometry. The π-d conjugated framework exhibits typical semiconducting behavior with a high electrical conductivity of ca. 1.0 S m -1 at room temperature. Benefiting from the good electrical conductivity and the excellent redox reversibility of both ligand and copper centers, Cu-DBC electrode features superior capacitor performances with gravimetric capacitance up to 479 F g -1 at a discharge rate of 0.2 A g -1 . Moreover, the symmetric solid-state supercapacitor of Cu-DBC exhibits high areal (879 mF cm -2 ) and volumetric (22 F cm -3 ) capacitances, as well as good rate capability. These metrics are superior to most reported MOF-based supercapacitors, demonstrating promising applications in energy-storage devices., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Single-atom catalysts are emerging as a new frontier in heterogeneous catalysis because of their maximum atom utilization efficiency, but they usually suffer from inferior stability. Herein, we synthesized single-atom Rh catalysts embedded in MFI-type zeolites under hydrothermal conditions and subsequent ligand-protected direct H 2 reduction. C s -corrected scanning transmission electron microscopy and extended X-ray absorption analyses revealed that single Rh atoms were encapsulated within 5-membered rings and stabilized by zeolite framework oxygen atoms. The resultant catalysts exhibited excellent H 2 generation rates from ammonia borane (AB) hydrolysis, up to 699 min -1 at 298 K, representing the top level among heterogeneous catalysts for AB hydrolysis. The catalysts also showed superior catalytic performance in shape-selective tandem hydrogenation of various nitroarenes by coupling with AB hydrolysis, giving >99 % yield of corresponding amine products., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Accurate measurements and assessments of gas adsorption isotherms are important to characterize porous materials and develop their applications. Although these isotherms provide knowledge of the overall gas uptake within a material, they do not directly give critical information concerning the adsorption behaviour of adsorbates in each individual pore, especially in porous materials in which multiple types of pore are present. Here we show how gas adsorption isotherms can be accurately decomposed into multiple sub-isotherms that correspond to each type of pore within a material. Specifically, two metal-organic frameworks, PCN-224 and ZIF-412, which contain two and three different types of pore, respectively, were used to generate isotherms of individual pores by combining gas adsorption measurements with in situ X-ray diffraction. This isotherm decomposition approach gives access to information about the gas uptake capacity, surface area and accessible pore volume of each individual pore, as well as the impact of pore geometry on the uptake and distribution of different adsorbates within the pores.

Improving the stability and tuning the optical properties of semiconducting perovskites are vital for their applications in advanced optoelectronic devices. We present a facile synthetic method for hybrid composites of perovskites and metal-organic frameworks (MOFs). A simple two-step solution-based method without organic surfactants was employed to make all-inorganic lead-halide perovskites (CsPbX 3 ; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF. That is, a polar organic solution of lead halide (PbX 2 ) was impregnated into the MOF pores to give PbX 2 @MIL-101, which was then subjected to a perovskite-formation reaction with cesium halide (CsX) dissolved in methanol. The compositions of the halogen anions in the perovskites can be modulated with various halide precursors, leading to CsPbX 3 @MIL-101 composites with X 3 = Cl 3 , Cl 2 Br, Br 2 Cl, Br 3 , Br 2 I, I 2 Br, and I 3 that exhibit gradual variation of band gap energies and tuned emission wavelengths from 417 to 698 nm.

Hierarchical nanozeolites are highly desired for heavy oil conversion because of their fast mass transfer, good site accessibility, and short diffusion length compared with their conventional counterparts. Here, we provide a facile amino acid-assisted strategy to synthesize hierarchical ZSM-5 (MFI) zeolite nanocrystals by two-step crystallization in a concentrated gel system. Strikingly, each virus-like zeolite nanoparticle with abundant interconnected intracrystalline mesopores is a high-quality single crystal that is defect-free as confirmed by electron diffraction and NMR analysis. By utilizing advanced electron microscopy techniques, we have studied the evolution process of single-crystalline hierarchical ZSM-5 nanocrystals that involves oriented aggregation of protozeolitic nanoparticles formed at low temperature followed by intraparticle ripening at high temperature. The as-prepared hierarchical Ni@ZSM-5 catalysts exhibit superior catalytic performance in hydrodeoxygenation of stearic acid and palm oil.

A conceptual design and synthesis of ordered mesoporous zeolites is a challenging research subject in material science. Several seminal articles report that one-dimensional (1D) mesostructured lamellar zeolites are possibly directed by sheet-assembly of surfactants, which collapse after removal of intercalated surfactants. However, except for one example of two-dimensional (2D) hexagonal mesoporous zeolite, no other zeolites with ordered 2D or three-dimensional (3D) mesostructures have been reported. An ordered 2D mesoporous zeolite can be templated by a cylindrical assembly unit with specific interactions in the hydrophobic part. A template molecule with azobenzene in the hydrophobic tail and diquaternary ammonium in the hydrophilic head group directs hierarchical MFI zeolite with a 2D square mesostructure. The material has an elongated octahedral morphology, and quaternary, ordered, straight, square channels framed by MFI thin sheets expanded along the a-c planes and joined with 90° rotations. The structural matching between the cylindrical assembly unit and zeolite framework is crucial for mesostructure construction., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The structural analysis of silica mesoporous crystals (SMCs) is a key step for understanding their properties, especially toward drug delivery. Although various techniques can be applied, electron crystallography has been proved the most powerful method in the structure solution of mesoporous materials. In this chapter, we will begin with introducing basic crystallography and extend to the 3D structure solution using a set of HRTEM images. Typical examples will also be given to show the structure features of 2D, 3D, cage-type, and hyperbolic surface-type mesostructures. A drug delivery system using SMCs as a reservoir will be given at the end., (© 2018 Elsevier Inc. All rights reserved.)

Developing synthetic methodology to crystallize extended covalent structures has been an important pursuit of reticular chemistry. Here, we report a homogeneous synthetic route for imine covalent organic frameworks (COFs) where crystallites emerge from clear solutions without forming amorphous polyimine precipitates. The key feature of this route is the utilization of tert-butyloxycarbonyl group protected amine building blocks, which are deprotected in situ and gradually nucleate the crystalline framework. We demonstrate the utility of this approach by crystallizing a woven covalent organic framework (COF-112), in which covalent organic threads are interlaced to form a three-dimensional woven framework. The homogeneous imine COF synthesis also enabled the control of nucleation and crystal growth leading to uniform nanocrystals, through microwave-assisted reactions, and facile preparation of oriented thin films.

About 15 years ago, the Ryoo group described the synthesis of CMK-5, a material consisting of a hexagonal arrangement of carbon nanotubes. Extension of the surface casting synthesis to oxide compositions, however, was not possible so far, in spite of many attempts. Here it is demonstrated, that crystalline mesoporous hollow zirconia materials with very high surface areas up to 400 m 2  g -1 , and in selected cases in the form of CMK-5-like, are indeed accessible via such a surface casting process. The key for the successful synthesis is an increased interaction between the silica hard template surface and the zirconia precursor species by using silanol group-rich mesoporous silica as a hard template. The surface areas of the obtained zirconias exceed those of conventionally hard-templated ones by a factor of two to three. The surface casting process seems to be applicable also to other oxide materials., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Chiral crystals can be exploited for applications in enantioselective separation and catalysis. However, the study of chirality at the atomic level in a sub-micrometre-sized crystal is difficult due to the lack of adequate characterization methods. Herein, we present two efficient and practical methods of characterization that are based on electron crystallography. These methods are successfully applied to reveal the handedness of a chiral, zeolite nanocrystal. The handedness is identified through either a comparison of two high-resolution transmission electron microscope images, taken from the same nanocrystal but along different zone axes by tilting it around its screw axis, or the intensity asymmetry of a Bijvoet pair of reflections in a single precession electron-diffraction pattern. These two approaches provide new ways to determine the handedness of small, chiral crystals.

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity)., Competing Interests: The authors declare no conflict of interest.