Publications by authors named "Yoshifumi Kondo"

Article Synopsis
  • Layered alkali titanates, known for their unique properties, are typically synthesized through a hydrothermal method that is environmentally detrimental due to high alkali concentration.
  • A new bottom-up chemical synthesis method has been developed for large-scale production of sodium titanate, significantly reducing alkali raw material usage by 99.6% compared to traditional methods.
  • The optimal Na:Ti molar ratio discovered (1.1:1) ensures effective ionization of materials, while maintaining similar crystal structures across varying ratios, suggesting promising applications in photofunctional materials.
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Lepidocrocite-type layered sodium titanate (NaHTiO) is widely used in environmental remediation because of its large specific surface area, formed by anisotropic crystal growth, and its ability to store and exchange cations between layers. Additionally, peroxo-titanate nanotubes (PTNTs), which are tubular titanates with peroxy groups, exhibit visible-light absorption capabilities, rendering them suitable for photocatalytic applications under visible light irradiation. However, because of cation exchange reactions, the Na concentration and pH of the solution can fluctuate under aqueous conditions, affecting the photocatalytic performance of the PTNTs.

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Using melt-derived LD glass powders and 5-20 M NaOH solutions, porous lithium disilicate (LiSiO, LD) glass-ceramics were prepared by the cold sintering process (CSP) associated with the post-annealing technique. In this novel technique, HO vapor originating from condensation reactions between residual Si-OH groups in cold-sintered LD glasses played the role of a foaming agent. With the increasing concentration of NaOH solutions, many more residual Si-OH groups appeared, and then rising trends in number as well as size were found for spherical pores formed in the resultant porous LD glass-ceramics.

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We report a case of unresectable advanced esophageal cancer with an esophageal fistula that was treated with pembrolizumab plus CDDP plus 5-FU therapy and the fistula was closed. A 73-year-old male was diagnosed with cervical-upper thoracic esophageal cancer and esophago-bronchial fistula on CT and esophagogastroduodenoscopy. He underwent chemotherapy containing pembrolizumab.

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Al-MIL-101-NH, which was previously regarded as being inactive as a photocatalyst, produces hydrogen peroxide (HO) O reduction under visible-light irradiation, accompanied by efficient suppression of undesired HO decomposition. The low-coordination Lewis acid sites in trimetric Al-oxo clusters are crucial for the electron transfer to O.

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Layered sodium titanate is a typical ion-exchanger for water purification aimed at removing cationic heavy metals and radionuclides. The material design of an ion-exchanger is effective for cation removal. For that purpose, understanding the basic impacts of crystallographic properties such as crystal size, morphology, and phase is critical for developing highly functional nanoscale ion-exchangers.

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Case 1: A 51-year-old man underwent total gastrectomy for esophagogastric junction cancer. Pathological diagnosis was alpha-fetoprotein(AFP)producing cancer. One month after the surgery, lung metastasis was found on CT.

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Falciform ligament hernia is a very rare internal hernia and is difficult to diagnose before surgery. We report a case of falciform ligament hernia with a specific symptom and image findings, which led to an accurate diagnosis and subsequent laparoscopic surgery. A 15-year-old adolescent boy with no previous medical history showed epigastric pain and was referred to our hospital.

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The development of new technologies for securing and recycling water resources are in high demand. A key focus of these technologies is the development of various ion exchangers or adsorbents that are used for the purification of aqueous solutions. Layered sodium titanate is one of the cation exchangers utilised in the removal of heavy metals and radionuclides from wastewater.

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A 51-year-old male underwent total gastrectomy for esophagogastric junction cancer(T3N0M0, Stage ⅡA). He was diagnosed with an alpha-fetoprotein(AFP) producing tumor and hepatoid adenocarcinoma. One month after radical surgery, computed tomography(CT) showed lung metastasis, and the patient's serum AFP level was high.

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As an environmentally friendly and renewable energy source, hydrogen peroxide (H2O2) could be produced photocatalytically through selective two-electron reduction of O2 using effective photocatalysts. Metal organic frameworks (MOFs), as hybrid porous materials consisting of organic linkers and metal oxide clusters, have aroused great interest in the design of effective catalysts for photocatalysis under visible light irradiation due to their unique properties, such as large surface area, good chemical stability, and diverse and tunable chemical components. In this perspective, we highlight our recent progress in the application of various MOF-based nanomaterials for photocatalytic H2O2 production from the selective two-electron reduction of O2 in a single-phase system (acetonitrile) and two-phase system (water/benzyl alcohol).

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Photocatalytic H2O2 production via two-electron reduction of O2 was realized by visible-light irradiation of a metal-organic framework, MIL-125-NH2, in the presence of TEOA and benzylalcohol. Deposition of NiO nanoparticles onto MIL-125-NH2 dramatically enhanced the catalytic activity. Further studies suggested that fast disproportionation of the O2˙- intermediate to H2O2 resulted in the enhancement.

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