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Promotional effect of silica shell coated NiO physically mixed with Mo/HZSM-5 catalyst on methane dehydroaromatization
No full textIn our previous study, the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization (MDA) reaction. It has been confirmed that the physically mixed NiO not only promoted the dispersion of MoCx active sites but also reduced the coke formation on the MoCx owing to the CNTs growth on Ni. However, the promotional effect of NiO was limited when the particle size was reduced, due to the excessive interaction with MoOx (forming NiMoO4) which is detrimental to the MoCx dispersion. In this study, to overcome the limitation, silica shell on NiO particles with various sizes (5, 15, 110 nm) was introduced. The catalyst with silica shell coated NiO with the size of 15 nm exhibited a significant improvement in both BTX yield and stability, and the catalyst with silica shell coated NiO with the size of 5 nm achieved the highest maximum BTX yield, about 7.2%. This study demonstrates that the catalytic performance improved as the NiO particle size decreased with the introduction of the silica shell. Combined transmission electron microscopy-energy dispersive spectroscopy, X-ray diffraction, temperature-programmed surface reaction of methane, CO chemisorption, visible Raman, and thermogravimetric analysis allowed us to confirm that a thin silica shell further enhances the MoCx dispersion while preventing the formation of Ni-Mo complexes. However, when the size of NiO decreased to 5 nm, CNT growth on Ni was limited during the reaction, which is crucial for reducing coke formation on Mo active sites, thereby resulting in the decreased catalyst stabilization ability of Ni. Overall, this study indicates that the introduction of a silica shell in a controlled way can significantly enhance the promotional effect of physically mixed NiO on MDA. (c) 2025, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.N
Development of the First Shuttle Vector System and Optimization of Transformation in Selenomonas sputigena
No full textSelenomonas sputigena, an anaerobic bacterium found in the human respiratory tract, has recently gained significant attention due to its dual role in human health - as both a periodontal pathogen and a protective agent against severe asthma. However, the absence of genetic tools for this organism has severely limited our understanding of its molecular mechanisms and therapeutic potential. Here, we report the first successful development of a genetic modification system for S. sputigena ATCC 35185. We constructed a shuttle vector carrying the Rep191 replication protein from Selenomonas ruminantium and systematically optimized transformation conditions. Through careful optimization of key parameters including DNA quantity, bacterial growth phase, membrane permeabilization, and post-pulse recovery time, we achieved a 22.5-fold improvement in transformation efficiency (from "2,000 to "45,000 CFU/mu g DNA). The broad applicability of our system was demonstrated through successful transformation of multiple Selenomonas species, establishing the first standardized genetic modification system for this genus. We further validated the system's functionality by achieving stable GFP expression in S. sputigena, representing the first demonstration of ectopic protein expression in this organism. This work provides essential tools for investigating the molecular basis of S. sputigena's therapeutic effects and pathogenic capabilities, potentially accelerating the development of novel microbiome-based treatments for both respiratory and oral diseases.N
Radiopaque hydrogel-in-liposomes towards theranostic applications for malignant tumors
No full textA radiopaque hydrogel-in-liposome (RHL) system was developed for micro-computed tomography (μCT) imaging of tumor tissue and simultaneous delivery of a cytotoxic agent. Iopamidol (IPD) and doxorubicin (DOX) were incorporated as the CT contrast and anti-cancer agents, respectively. The presence of a polyethylene glycol hydrogel core in the liposomes was confirmed via attenuated total reflectance Fourier transform infrared, proton nuclear magnetic resonance, and selective solvent extraction. Nano-sized (∼160 nm) spherical DOX/IPD-loaded RHLs with a narrow size distribution and negative zeta potential were successfully fabricated. The RHLs demonstrated enhanced cellular uptake of DOX in SCCVII cells compared to conventional radiopaque liposomes, likely due to clathrin-mediated endocytosis. Additionally, pH-dependent DOX release and reduced IPD leakage were observed. In vivo studies using SCCVII tumor-xenografted mice showed that RHLs exhibited improved CT contrast efficiency and anti-tumor efficacy, along with systemic biocompatibility, attributed to enhanced tumor-targeting properties. These findings suggest that the RHL system could serve as a promising nano-platform for tumor theranostics.Y
Wafer-Scale Semitransparent MoS2/WS2 Heterojunction Catalyst on a Silicon Photocathode for Efficient Hydrogen Evolution
No full textThe development of catalysts that are optically transparent, electrically charge-transferable, and capable of protecting underlying photoactive semiconductors is crucial for efficient photoelectrochemical (PEC) hydrogen production. However, meeting all these requirements simultaneously poses significant challenges. In this study, the fabrication of a wafer-scale transparent bilayer MoS2/WS2 catalyst is presented with a staggered heterojunction, optimized for photon absorption, extraction of photogenerated charge carriers, and surface passivation of p-Si photocathode. The MoS2 and WS2 monolayers are grown via metal-organic chemical vapor deposition, followed by sequential transfer and stacking onto the p-Si photocathode. The resulting type-II heterojunction film establishes a strong built-in electric field for rapid charge carrier transport and effectively protects the Si surface from oxidation and corrosion. The fabricated MoS2/WS2/p-Si photocathode demonstrates outstanding PEC performance, achieving a high photocurrent density of -25 mA cm-2 at 0 V versus reversible hydrogen electrode, along with enhanced stability compared to monolayer MoS2/p-Si. This work provides promising strategies for developing optically transparent, electrically active, and protective catalysts for practical PEC energy conversion systems.Y
CENTRAL BANK DIGITAL CURRENCY AND PRIVACY: A RANDOMIZED SURVEY EXPERIMENT
No full textPrivacy protection is among the key features to consider in the design of central bank digital currency (CBDC). Using a nationally representative sample of over 3,500 participants, we conduct a randomized online survey experiment to examine how the willingness to use CBDC as a means of payment varies with the degree of privacy protection and information provision on the privacy benefits of using CBDC. We find that both factors significantly increase participants' willingness to use CBDC by up to 64% when purchasing privacy-sensitive products. Our findings provide useful insights regarding the design and the public's adoption of CBDC.N
Retinal Organoids from Induced Pluripotent Stem Cells of Patients with Inherited Retinal Diseases: A Systematic Review
No full textBackgroundCurrently, most inherited retinal diseases lack curative interventions, and available treatment modalities are constrained to symptomatic approaches. Retinal organoid technology has emerged as a method for treating inherited retinal diseases, with growing academic interest in recent years. The purpose of this review was to systematically organize the current protocols for generating retinal organoids using induced pluripotent stem cells from patients with inherited retinal disease and to investigate the application of retinal organoids in inherited retinal disease research.MethodsData were collected from the PubMed, Scopus, and Web of Science databases using a keyword search. The main search term used was "retinal organoid," accompanied by secondary keywords such as "optic cup," "three-dimensional," and "self-organizing." The final search was conducted on October 2, 2024.ResultsOf the 2,129 studies retrieved, 130 were included in the qualitative synthesis. The protocols for the generation of retinal organoids in inherited retinal disease research use five major approaches, categorized into 3D and a combination of 2D/3D approaches, implemented with modifications. Disease phenotypes have been successfully reproduced via the generation of retinal organoids from the induced pluripotent stem cells of individuals with inherited retinal diseases, facilitating the progression of research into novel therapeutic developments. Cells have been obtained from retinal organoids for cell therapy, and progress toward their potential integration into clinical practice is underway. Considering their potential applications, retinal organoid technology has shown promise across various domains.ConclusionIn this systematic review, we organized protocols for generating retinal organoids using induced pluripotent stem cells from patients with inherited retinal diseases. Retinal organoid technology has various applications including disease modeling, screening for novel therapies, and cell replacement therapy. Further advancements would make this technology a clinically significant tool for patients with inherited retinal diseases.Y
Optimization of Ionomer for High-Performance Self-Humidifying Air-Breathing Proton-Exchange Membrane Fuel Cells in Portable Device Power Systems
No full textThis study investigates the impact of ionomer types and content in the catalyst layer on the performance of proton exchange membrane fuel cells (PEMFCs) under room temperature and atmospheric pressure. Four commercially available ionomers with varying equivalent weights (EWs) and side-chain lengths are evaluated as catalyst layer binders in membrane-electrode assemblies (MEAs). The assessments are conducted at room temperature and ambient pressure without additional humidification, focusing on understanding the distinctive characteristics of each ionomer. In addition, this study investigates the prospective application of an air-breathing passive-type cell, dependent exclusively on natural convection for air supply. The notable performance of the passive-type cell shown in this study indicates its suitability as a compact mobile power source, especially for drone applications. Furthermore, the stability of various ionomer binders is also compared to establish a correlation between EW and side-chain length of ionomer binder stability. Overall, the findings will serve as a valuable reference for optimizing ionomer selection and composition in specialized applications for powering portable devices. Various commercial ionomer binders under room temperature and atmospheric pressure were investigated with passive-type PEMFC.image (c) 2024 WILEY-VCH GmbHY
Orally Deliverable Iron-Ceria Nanotablets for Treatment of Inflammatory Bowel Disease
No full textCeria-based nanoparticles are versatile in treating various inflammatory diseases, but their feasibility in clinical translation is undermined by safety concerns and a limited delivery system. Meanwhile, the idiopathic nature of inflammatory bowel disease (IBD) calls for a wider variety of therapeutics via moderation of the intestinal immune system. In this regard, the synthesis and oral formulation of iron-ceria nanoparticles (CF NPs) with enhanced nanozymic activity and lower toxicity risk than conventional ceria-based nanoparticles are reported. CF NPs are clustered in calcium phosphate (CaP) and coated with a pH-responsive polymer to provide the enteric formulation of iron-ceria nanotablets (CFNT). CFNT exhibits a marked alleviative efficacy in the dextran sodium sulfate (DSS)-induced enterocolitis model in vivo by modulating the pro-inflammatory behavior of innate immune cells including macrophages and neutrophils, promoting anti-inflammatory cytokine profiles, and downregulating key transcription factors of inflammatory pathways. For enteric delivery of ceria-based anti-inflammatory nanozymes, iron-ceria nanoparticles with lower toxicity and higher catalytic activity are formulated into iron-ceria nanotablets (CFNT). Orally administered CFNT provides therapeutic efficacy on the enterocolitis model in vivo by manipulating the behavior of immune cells, cytokine secretion, and transcription factors toward an anti-inflammatory environment. imageN