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The syntheses and characterization of five to 18-membered heterocyclic ethers containing polyfluoroalkyl pendant chains are described. The fluorinated side chains were introduced via free radical reactions of poly- and perfluoroalkenes with nonhalogenated oxygen-containing heterocycles. The preparation and single-crystal X-ray analysis of lanthanum triflate complexes of 18-crown-6 and 18-crown-6(CF2CFHCF3) are also described.

Intestinal dysbiosis and the associated l-tryptophan metabolic disorder are pivotal in inflammatory bowel disease progression, leading to a compromised intestinal barrier integrity. Remedying the dysfunction in tryptophan metabolism has emerged as a promising therapeutic strategy. Herein, we reprogram the tryptophan metabolism in situ by EcN-TRP@A/G, encapsulating the engineered probiotic, EcN-TRP, with enhanced tryptophan synthesis capacity, for sustained modulation, thereby restoring intestinal barrier function and microbial homeostasis. The pH-responsive dual-layered EcN-TRP@A/G microcapsule developed via high-voltage electrospraying and liquid interface self-assembly, preserved probiotic viability in the harsh gastrointestinal milieu, and facilitated targeted colon release. Bioluminescent tracking in mice reveals a 22.84-fold increase in EcN-TRP@A/G viability and distribution compared to naked EcN-TRP. Targeted metabolomics highlights EcN-TRP@A/G's modulation of the tryptophan-indole pathway. Oral administration of EcN-TRP@A/G sustained elevates indole metabolites, particularly indole-3-acetic acid and indole-3-propionic acid, in colon tissue for up to 7 days. In IBD mice, EcN-TRP@A/G improves intestinal permeability, reduces inflammation, and recovers the gut microbiome by enhancing beneficial bacteria abundance like Prevotellaceae_UCG-001 and Anaerostipes while suppressing pathogenic strains like Escherichia - Shigella . Our findings offer a cost-effective approach, harnessing the probiotic metabolic potential in situ through engineered modifications for effective IBD treatment.

The atomic substitution in two-dimensional (2D) materials is propitious to achieving compositionally engineered semiconductor heterostructures. However, elucidating the mechanism and developing methods to synthesize 2D heterostructures with atomic-scale precision are crucial. Here, we demonstrate the synthesis of monolayer WSe 2 -WS 2 heterostructures with a relatively sharp interface from monolayer WSe 2 using a chalcogen atom-exchange synthesis route at high temperatures for short periods. The substitution was initiated at the edges of monolayer WSe 2 and the lateral diffuse along the heterointerface, and the reaction can be controlled by the precise reaction time and temperature. The lateral heterostructure and substitution process are studied by Raman and photoluminescence (PL) spectroscopies, electron microscopy, and device characterization, revealing a possible mechanism of strain-induced transformation. Our findings demonstrate a highly controllable synthesis of 2D layered materials through atom substitutional chemistry and provide a simple route to control the atomic structure.

Group-VA two-dimensional layered materials in a puckered honeycomb structure exhibit strong in-plane anisotropy and have emerged as new platforms for novel devices. Here, we report on systematic Raman investigations on exfoliated b-As flakes on the A g 1 and A g 2 polarization dependence on their symmetry, excitation wavelength, and flake thickness. The intensity maximums of both phonons are corrected in the b-As armchair direction under 633 nm excitation regardless of the flake thickness upon considering optical birefringence effects and interference effects. The intensity ratio of A g 1 to A g 2 modes under 532 nm excitation is useful for b-As crystalline orientation identification. Temperature-dependent Raman investigations reveal the linearly anharmonic behaviors of both phonons in the range from 173 to 293 K and a slightly greater first-order temperature coefficient in the zigzag direction. Our findings give deep insight into the in-plane phonon anisotropy and anharmonicity of b-As and provide a step toward future device applications.

Atomically thin transition-metal dichalcogenide (TMDC) heterostructures have attracted increasing attention because of their unprecedented potential in the fields of electronics and optoelectronics. However, selective growth of either lateral or vertical TMDC heterostructures remains challenging. Here, we report that lateral and vertical MoS 2 /MoSe 2 epitaxial heterostructures can be successfully fabricated via a one-step growth strategy, which includes triggering by the concentration of sulfur precursor vapor and a high-temperature annealing process. Vertically stacked MoS 2 /MoSe 2 heterostructures can be synthesized via control of the nucleation and growth kinetics, which is induced by high sulfur vapor concentration. The high-temperature annealing process results in the formation of fractured MoSe 2 and in situ epitaxial growth of lateral MoSe 2 -MoS 2 heterostructures. This study has revealed the importance of sulfur vapor concentration and high-temperature annealing processes in the controllable growth of MoSe 2 -MoS 2 heterostructures, paving a new route for fabricating two-dimensional TMDC heterostructures.

Growing uniform oxides with various thickness on TMDs is one of the biggest challenges to integrate TMDs into complementary metal oxide semiconductor (CMOS) logic circuits. Here, we report a layer-by-layer oxidation of atomically thin MoTe 2 flakes via ozone (O 3 ) exposure. The thickness of MoO x oxide film could be tuning with atomic-level accuracy simply by varying O 3 exposure time. Additionally, MoO x -covered MoTe 2 shows a hole-dominated transport behavior. Our findings point to a simple and effective strategy for growing homogeneous surface oxide film on MoTe 2 , which is promising for several purposes in metal-oxide-semiconductor transistor, ranging from surface passivation to dielectric layers.

Mesoporous zeolites are useful solid catalysts for conversion of bulky molecules because they offer fast mass transfer along with size and shape selectivity. We report here the successful synthesis of mesoporous aluminosilicate zeolite Beta from a commercial cationic polymer that acts as a dual-function template to generate zeolitic micropores and mesopores simultaneously. This is the first demonstration of a single nonsurfactant polymer acting as such a template. Using high-resolution electron microscopy and tomography, we discovered that the resulting material (Beta-MS) has abundant and highly interconnected mesopores. More importantly, we demonstrated using a three-dimensional electron diffraction technique that each Beta-MS particle is a single crystal, whereas most previously reported mesoporous zeolites are comprised of nanosized zeolitic grains with random orientations. The use of nonsurfactant templates is essential to gaining single-crystalline mesoporous zeolites. The single-crystalline nature endows Beta-MS with better hydrothermal stability compared with surfactant-derived mesoporous zeolite Beta. Beta-MS also exhibited remarkably higher catalytic activity than did conventional zeolite Beta in acid-catalyzed reactions involving large molecules.

We describe an inkjet printing assisted cooperative-assembly method for high-throughput generation of catalyst libraries (multicomponent mesoporous metal oxides) at a rate of 1,000,000-formulations/hour with up to eight-component compositions. The compositions and mesostructures of the libraries can be well-controlled and continuously varied. Fast identification of an inexpensive and efficient quaternary catalyst for photocatalytic hydrogen evolution is achieved via a multidimensional group testing strategy to reduce the number of performance validation experiments (25,000-fold reduction over an exhaustive one-by-one search).

A combined adsorption-discharge plasma catalytic process was used for the removal of NO(x) using zeolites as catalysts without external heating. It was found that the types of plasma carrier gases exert great effect on the conversion of adsorbed NO(x). The conversion of adsorbed NO(x) is much lower in N(2) plasma than in Ar plasma, which is attributed to the reverse reaction, NO(x) formation reaction. The momentary increase of oxygen species derived from the decomposition of adsorbed NO(x) is considered to be the main cause as their collisions with nitrogen species can generate NO(x) again. Thus, solid carbon was added to the catalyst to act as a scavenger for active oxygen species to improve the conversion of adsorbed NO(x) in N(2) plasma. A NO(x) removal rate of 97.8% was obtained on 8.5wt.% carbon mixed H-ZSM-5 at an energy efficiency of 0.758 mmol NO(x)/W·h.