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Lepidocrocite-type layered sodium titanate (NaxH2−xTi2O5) 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. Herein, we evaluated the impact of cation exchange reactions on the photocatalytic degradation of Rhodamine B (Rh B) by PTNTs at controlled Na+ ratios. The observed pH of Rh B solutions increases due to the cation exchange reaction with Na+ and H3O+, leading to the formation of zwitter-ionic Rh B molecules, eventually weakening their adsorption and photodegradation performance. Moreover, the results indicate that inhibiting the pH increase of the Rh B solution can prevent the weakening of both the adsorption and photodegradation performance of PTNTs. This study highlights the significance of regulating the sodium ion content in layered titanate materials, emphasizing their importance in optimizing these materials' photocatalytic efficacy for environmental purification applications. [ABSTRACT FROM AUTHOR]

Layered alkali titanates of the lepidocrocite type are gaining enormous interest in various fields owing to their unique properties. These materials are mainly synthesized through a hydrothermal alkali treatment. However, this method uses a highly concentrated alkali solution, which has high environmental impacts and is therefore unsuitable for mass synthesis. Herein, we propose an efficient method for the large-scale synthesis of layered sodium titanate structures (Na 2- x H x Ti 2 O 5 ) using a recently reported bottom-up chemical process. The effects of the Na:Ti molar ratio in the peroxo-titanium complex ion precursor on the products are investigated through stoichiometric calculations for a molar ratio range of 10:1-1:1. The optimal ratio for the complete ionization of TiH 2 (which is the starting material) to form the peroxo-titanium complex ion is found to be 1.1:1. The amount of alkali raw material required is 99.6% lower than that required in the traditional hydrothermal method. The crystal structures and morphologies of the samples are almost identical regardless of the Na:Ti molar ratio. The precursor-derived peroxo bonds narrow the energy band gaps of the layered titanates even when the amount of titanium ions dissolved in the precursor increases. The proposed method is not only an efficient synthetic route for mass production but also has potential applications in the development of photofunctional materials., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

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. The fistula was closed after 4 cycles and oral intake became possible. Six months have passed since the first visit and chemotherapy is ongoing. The prognosis of esophago-bronchial fistula is extremely poor, and there is no established treatment, including fistula closure. Chemotherapy containing immune checkpoint inhibitors could considered to be expected not only for local control but also for long-term survival.

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. In this study, we investigate the principal relationship between the crystallographic properties of seaweed-like sodium titanate mats (SSTs), which consist of a dititanate (H x Na 2- x Ti 2 O 5 ) phase of nanofibers synthesised by the alkaline hydrothermal method and their Sr 2+ sorption mechanism. A trititanate (H x Na 2- x Ti 3 O 7 ) phase, which has a micro-sized fibre morphology, was also synthesised using the same method by adjusting the NaOH concentration. The SST demonstrates a high ion-exchange selectivity of Sr 2+ against H + and a high maximum sorption capacity (2 mmol g -1 ), which was four times higher than that of the trititanate phase (0.49 mmol g -1 ). In contrast, the trititanate phase, which is the comparison target, had a low Sr 2+ ion-exchange selectivity and precipitated SrCO 3 . We conclude that these differences in Sr 2+ sorption mechanisms were derived from not only the unique morphology but also the crystal structure of sodium titanates. Although almost all of the Na + in dititanate with lamellar structure was consumed by the ion-exchange reaction, some Na + remained in the trititanate because there are two sites in the zigzag layered structure. These findings on the crystallographic properties of SST for Sr 2+ sorption may contribute to the functionalisation of a nanoscale ion-exchanger., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

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. Despite systemic chemotherapy, he died 4 months after the surgery. Case 2: A 79-year-old man underwent open distal gastrectomy for gastric cancer. Pathological diagnosis was AFP producing cancer. Six months after the surgery, multiple lymph node metastases were found on CT. He received chemotherapy and radiation therapy. He is currently alive 9 years 8 months after the surgery.

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. To enhance the removal efficiency, the precise design of the crystal morphology, structure, and chemical composition is important. Herein, we synthesised a unique seaweed-like sodium titanate mat (SST) using a template-free alkaline hydrothermal process. The Co 2+ sorption capacity of SST was investigated by batch testing with cobalt(ii) nitrate. SST, which was synthesised from titanium sulphate in a 10 M NaOH solution at 200 °C, had a seaweed-like structure composed of randomly distributed nanofibres of layered sodium titanate that is approximately 9 nm in diameter. The crystal shape changed from roundish crystals to fibrous crystals as the hydrothermal reaction period increased. The Co 2+ sorption isotherm of SST was fitted with the Langmuir isotherm model and the maximum sorption density was 1.85 mmol g -1 . The selectivity of the Co 2+ sorption on SST was high in comparison to that of Ca 2+ and Mg 2+ . Herein, the Co 2+ sorption mechanisms of SST were studied in comparison with commercially available sodium titanate. Results show that controlling the crystal morphology, structure, and Na concentration of the layered titanate that can be ion-exchanged determines the cation sorption properties of sodium titanate., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

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. He underwent chemotherapy( S-1 and wPTX/RAM)and eventually died 4 months after surgery.