Impact of the COVID-19 Pandemic on Hypofractionated Radiation Therapy Use for Breast Cancer in Japan: A Nationwide Study.

Purpose: Hypofractionated radiation therapy (RT) was recommended for several cancer sites to reduce outpatient visits during the COVID-19 pandemic. This study aimed to identify the impact of the pandemic on hypofractionated RT for breast cancer in Japan. Methods and Materials: The monthly number of courses for hypofractionated and conventional RTs was counted using sample data sets from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, a nationwide database accumulating insurance claims data comprehensively. Changes in the number of hypofractionated and conventional RTs were estimated using an interrupted time-series analysis. Results: The number of hypofractionated RT courses gradually increased before the pandemic in contrast to that of conventional RT courses, which gradually decreased. However, conventional RT remained outnumbered by hypofractionated RT throughout the observation period. After the outbreak of the pandemic, the use of hypofractionated RT significantly increased in April 2020 (1312 courses; 95% CI, 801-1823) but decreased in October 2020 (-601; 95% CI, -1111 to -92). Subgroup analysis by age and the number of beds in medical institutions revealed similar trends. Conclusions: Although conventional RT for breast cancer has been gradually replaced by hypofractionated RT, it remains predominant. The use of hypofractionated RT increased briefly early in the COVID-19 pandemic; however, this increase was not sustained, unlike in other countries. Considering the benefits of hypofractionated RT for breast cancer, its use should be encouraged in Japan.

Heterogeneously catalyzed thioether metathesis by a supported Au-Pd alloy nanoparticle design based on Pd ensemble control.

C-S bond metathesis of thioethers has gained attention as a new approach to the late-stage diversification of already existing useful thioethers with molecular frameworks intact. However, direct or indirect thioether metathesis is scarcely reported, and heterogeneously catalyzed systems have not been explored. Here, we develop heterogeneously catalyzed direct thioether metathesis using a supported Au-Pd alloy nanoparticle catalyst with a high Au/Pd ratio. The Au-diluted Pd ensembles suppress the strong π-adsorption of diaryl thioethers on the nanoparticles and promote transmetalation via thiolate spill-over onto neighboring Au species, enabling an efficient direct thioether metathesis.

Synthesis of a Gold-Silver Alloy Nanocluster within a Ring-Shaped Polyoxometalate and Its Photocatalytic Property.

Alloying is an effective method for modulating metal nanoclusters to enrich their structural diversity and physicochemical properties. Recent investigations have demonstrated that polyoxometalates (POMs) can act as effective multidentate ligands for silver (Ag) nanoclusters to endow them with synergistic properties, reactivity, catalytic properties, and stability. However, the application of POMs as ligands has been confined predominantly to monometallic nanoclusters. Herein, we report a synthetic method for fabricating surface-exposed gold (Au)-Ag alloy nanoclusters within a ring-shaped POM ([P8W48O184]40-). Reacting an Ag nanocluster stabilized by the ring-shaped POM with Au ions (Au+) was found to substitute several Ag atoms at the core of the nanocluster with Au atoms. The resultant {Au8Ag26} alloy nanocluster demonstrated superior photocatalytic activity and stability compared to the pristine Ag nanocluster in the aerobic oxidation of α-terpinene under visible-light irradiation. These findings provide fundamental insights into the formation and catalytic properties of POM-stabilized alloy nanoclusters and advance exploration into the synthesis and applications of diverse metal nanoclusters.

Long-term outcome of regional cooperation pathway after endoscopic submucosal dissection for early detection of new gastric cancer.

OBJECTIVES: The Cancer Control Act requires the maintenance of regional cooperation pathways (RCP) for cancer treatment. In 2008, we started RCP for early detection of new gastric cancer after endoscopic submucosal dissection (ESD). In gastric cancer treatment, RCP after surgical resection had been widely used, but little is known about RCP after ESD. This study aimed to evaluate the effectiveness of RCP after ESD. METHODS: This study included 465 patients on whom our RCP was implemented from 2008 to 2018. A regional family physician performed surveillance endoscopy at 3 months and 1 year after ESD and annually thereafter. We retrospectively evaluated the cumulative incidence and treatment outcomes of new gastric cancer and compared them with previous reports. RESULTS: During a median follow-up period of 70.5 months (3-120 months), 58 patients developed new gastric cancers, and metachronous gastric cancer was detected in 55 patients more than 1 year after ESD. The 5-year cumulative incidence rate was 9.8%. Three patients did not want treatment. Among the remaining 55 patients, the initial treatment was ESD in 51 and surgical resection in 4. Eventually, 50 patients (48 in the ESD group and 2 in the surgical resection group) fulfilled the pathologic criteria for curative ESD. There were no deaths due to gastric cancer. CONCLUSION: Our study was the first to reveal the incidence of new gastric cancer after ESD using RCP. Most lesions were cured with ESD, and no patients died of gastric cancer. Therefore, we consider RCPs to be an option for surveillance after ESD.

Synthesis of polyoxothiometalates through site-selective post-editing sulfurization of polyoxometalates.

Polyoxometalates (POMs) function as platforms for synthesizing structurally well-defined inorganic molecules with diverse structures, metals, compositions, and arrangements. Although post-editing of the oxygen sites of POMs has great potential for development of unprecedented structures, electronic states, properties, and applications, facile methods for site-selective substitution of the oxygen sites with other atoms remain limited. Herein, we report a direct site-selective oxygen-sulfur substitution method that enables transforming POMs [XW12O40]4- (X = Si, Ge) to Keggin-type polyoxothiometalates (POTMs) [XW12O28S12]4- using sulfurizing reagents in an organic solvent. The resulting POTMs retain the original Keggin-type structure, with all 12 surface W[double bond, length as m-dash]O groups selectively converted to W[double bond, length as m-dash]S without sulfurization of other oxygen sites. These POTMs show high stability against water and O2 in organic solvents and a drastic change in the electronic states and redox properties. The findings of this study represent a facile method for converting POMs to POTMs, leading to the development of their unique properties and applications in diverse fields, including (photo)catalysis, sensing, optics, electronics, energy conversion, and batteries.

Self-assembled molecular hybrids comprising lacunary polyoxometalates and multidentate imidazole ligands.

Self-assembly via coordination bonding facilitates the creation of diverse inorganic-organic molecular hybrids with distinct structures and properties. Recent advances in this field have been driven by the versatility of organic ligands and inorganic units. Lacunary polyoxometalates are a class of well-defined metal-oxide clusters with a customizable number of reactive sites and bond directions, which make them promising inorganic units for self-assembled molecular hybrids. Herein, we report a novel synthesis method for self-assembled molecular hybrids utilizing the reversible coordination of multidentate imidazole ligands to the vacant sites of lacunary polyoxometalates. We synthesized self-assembled molecular hybrids including monomer, dimers, and tetramer, demonstrating the potential of our method for constructing intricate hybrids with tailored properties and functionalities.

Multidentate polyoxometalate modification of metal nanoparticles with tunable electronic states.

To respond to the increasing demands for practical applications, stabilization and property modulation of metal nanoparticles have emerged as a key research subject. Herein, we present a viable protocol for preparing small metal nanoparticles (<5 nm; Ag, Pd, Pt, and Ru) via multidentate polyoxometalate (POM, [SiW9O34]10-) modification. In addition to enhancing stability, the POMs can modulate the electronic states of metal nanoparticles. Moreover, immobilization of the POM-modified metal nanoparticles on solid supports enables further tuning of the electronic states via a cooperative effect between the POMs and the supports without altering the particle size. Notably, POM-modified Pd nanoparticles on carbon support exhibited superior catalytic activity and selectivity in hydrogenation reactions in comparison with the catalyst without the POM modification.

Novel reconstruction using pedicled ileocolic interposition with intrathoracic esophago-ileal anastomosis after distal esophagectomy for esophagogastric junction cancer: A report of two cases.

There is no optimal reconstruction after radical distal esophagectomy for cancers of the esophagogastric junction. We designed a novel reconstruction technique using pedicled ileocolic interposition with intrathoracic anastomosis between the esophagus and the elevated ileum. Two patients underwent the surgery. Case 1 was a 70-year-old man with esophagogastric junction adenocarcinoma with 3 cm of esophageal invasion. Case 2 was a 70-year-old man with squamous cell carcinoma of the esophagogastric junction; the epicenter of which was located just at the junction. These two patients underwent radical distal esophagectomy and pedicled ileocolic interposition with intrathoracic anastomosis. They were discharged on postoperative days 17 and 14, respectively, with no major complication. Pedicled ileocolic interposition is characterized by sufficient elevation and perfusion of the ileum, which is fed by the ileocolic artery and vein. As a result, we can generally adapt this reconstruction method to most curable esophagogastric junction cancers.

Synthesis of Novel Polymers with Biodegradability by Main-Chain Editing of Chiral Polyketones.

Although the use of biodegradable plastics is suitable for unrecoverable, single-use plastic, their high production cost and much lower variety compared to commodity plastics limit their application. In this study, we developed a new polymer with potential biodegradability, poly(ketone/ester), synthesized from propylene and carbon monoxide. Propylene and carbon monoxide are easily available at low costs from fossil resources, and they can also be derived from biomass. Using an atom insertion reaction to the main chain of the polymer, the main-chain editing of the polymer molecule proceeded with up to 89% selectivity for atom insertion over main-chain cleavage.

Small Copper Nanoclusters Synthesized through Solid-State Reduction inside a Ring-Shaped Polyoxometalate Nanoreactor.

Cu nanoclusters exhibit distinctive physicochemical properties and hold significant potential for multifaceted applications. Although Cu nanoclusters are synthesized by reacting Cu ions and reducing agents by covering their surfaces using organic protecting ligands or supporting them inside porous materials, the synthesis of surface-exposed Cu nanoclusters with a controlled number of Cu atoms remains challenging. This study presents a solid-state reduction method for the synthesis of Cu nanoclusters employing a ring-shaped polyoxometalate (POM) as a structurally defined and rigid molecular nanoreactor. Through the reduction of Cu2+ incorporated within the cavity of a ring-shaped POM using H2 at 140 °C, spectroscopic studies and single-crystal X-ray diffraction analysis revealed the formation of surface-exposed Cu nanoclusters with a defined number of Cu atoms within the cavities of POMs. Furthermore, the Cu nanoclusters underwent a reversible redox transformation within the cavity upon alternating the gas atmosphere (i.e., H2 or O2). These Cu nanoclusters produced active hydrogen species that can efficiently hydrogenate various functional groups such as alkenes, alkynes, carbonyls, and nitro groups using H2 as a reductant. We expect that this synthesis approach will facilitate the development of a wide variety of metal nanoclusters with high reactivity and unexplored properties.

Photocatalytic aerobic α-oxygenation of amides to imides using a highly durable decatungstate tetraphenylphosphonium salt.

Decatungstate is a potent photocatalyst for hydrogen atom transfer (HAT) but faces degradation issues when using a typical tetra-n-butylammonium salt. Herein, we employed tetraphenylphosphonium as a countercation to yield a highly durable and efficient HAT photocatalyst, enabling α-oxygenation of amides to their corresponding imides using O2 as an oxidant.

The Development of the Regenerable Catalytic System in Selective Catalytic Oxidation of Ammonia with High N2 Selectivity.

Supported particulate noble-metal catalysts are widely used in industrial catalytic reactions. However, these metal species, whether in the form of nanoparticles or highly dispersed entities, tend to aggregate during reactions, leading to a reduced activity or selectivity. Addressing the frequent necessity for the replacement of industrial catalysts remains a significant challenge. Herein, we demonstrate the feasibility of the 'regenerable catalytic system' exemplified by selective catalytic oxidation of ammonia (NH3-SCO) employing Ag/Al2O3 catalysts. Results demonstrate that our highly dispersed Ag catalyst (Ag HD) maintains >90% N2 selectivity at 80% NH3 conversion and >80% N2 selectivity at 100% NH3 conversion after enduring 5 cycles of reducible aggregation and oxidative dispersion. Moreover, it consistently upholds over 98% N2 selectivity at 100% NH3 conversion after 10 cycles of Ar treatment. During the aggregation-dispersion process, the Ag HD catalyst intentionally aggregated into Ag nanoparticles (Ag NP) after H2 reduction and exhibited remarkable regenerable capabilities, returning to the Ag HD state after calcination in the air. This structural evolution was characterized through in situ transmission electron microscopy, atomically resolved high-angle annular dark-field scanning transmission electron microscopy, and X-ray absorption spectroscopy, revealing the on-site oxidative dispersion of Ag NP. Additionally, in situ diffuse reflectance infrared Fourier transform spectroscopy provided insights into the exceptional N2 selectivity on Ag HD catalysts, elucidating the critical role of NO+ intermediates. Our findings suggest a sustainable and cost-effective solution for various industry applications.

Impact of the COVID-19 pandemic on gastric surgery in Japan: A nationwide study using interrupted time-series analyses.

BACKGROUND AND AIM: Changes in the number of surgeries for gastric cancer during the coronavirus disease 2019 (COVID-19) pandemic have been reported, but data are insufficient to understand the impact at the national level. This study aimed to determine the impact of the COVID-19 pandemic on gastric surgery in Japan. METHODS: Insurance claims data registered from January 2015 to January 2021 were used. Changes in the number of endoscopic resections and gastrectomies for gastric cancer were estimated using an interrupted time-series analysis. RESULTS: The number of endoscopic resections significantly decreased in July 2020 (-1565; 95% confidence interval [CI]: -2022, -1108) and January 2021 (-539; 95% CI: -970, -109), and the number of laparoscopic surgeries significantly decreased in July 2020 (-795; 95% CI: -1097, -492), October 2020 (-313; 95% CI: -606, -19), and January 2021 (-507; 95% CI: -935, -78). Meanwhile, the number of open gastrectomies remained unchanged, and the number of robot-assisted gastrectomies steadily increased since their coverage by public health insurance in April 2018. CONCLUSIONS: The decreased number of endoscopic resections and laparoscopic surgeries in Japan suggests a decline in early-stage gastric cancer diagnosis, likely due to the suspension of gastric cancer screening and diagnostic testing during the pandemic. Meanwhile, the number of open and robot-assisted gastrectomies remained unchanged and increased, respectively, indicating that these applications were not affected by the pandemic-related medical crisis. These findings highlight that procedures for cancer diagnosis, including screening, should still be provided during pandemics.

Impact of the coronavirus disease 2019 pandemic on primary and metastatic lung cancer treatments in Japan: A nationwide study using an interrupted time series analysis.

BACKGROUND: The coronavirus disease 2019 pandemic prompted healthcare providers to use different approaches from the current standards of care. We aimed to identify the changes in the number of treatments for primary non-small cell lung cancer (NSCLC) and metastatic lung cancer during the pandemic. METHODS: We used nationwide insurance claims data from January 2015 to January 2021, and estimated changes in the number of treatments using an interrupted time series analysis. RESULTS: The number of surgical resections for primary NSCLC significantly decreased in April 2020 (-888; 95% confidence interval [CI]: -1530 to -246) and July 2020 (-1314; 95% CI: -1935 to -694), while the number of stereotactic body radiotherapies (SBRTs) increased in April 2020 (95; 95% CI: 8-182) and July 2020 (111; 95% CI: 24-198). The total number of treatments for primary NSCLC remained unchanged; however, non-significant decreases were observed in 2020. The number of surgical resections for metastatic lung cancer significantly decreased in April 2020 (-201; 95% CI: -337 to -65), but it eventually increased in July 2020 (170; 95% CI: 32-308). Additionally, the number of SBRTs significantly increased in April 2020 (37; 95% CI: 3-71) and October 2020 (57; 95% CI: 23-91). The total number of treatments for metastatic lung cancer was maintained, with an initial decrease in April 2020 followed by a subsequent increase in July and October 2020. CONCLUSION: In Japan, surgical triage for primary and metastatic lung cancer are likely to have been implemented during the pandemic. Despite these proactive measures, patients with primary NSCLC may have been untreated, likely owing to their undiagnosed disease, potentially leading to a deterioration in prognosis. By contrast, patients diagnosed with cancer prior to the pandemic are presumed to have received standard management throughout the course of the pandemic.

Multi-stimuli-responsive polymer degradation by polyoxometalate photocatalysis and chloride ions.

Photocatalytic polymer degradation based on harnessing the abundant light energy present in the environment is one of the promising approaches to address the issue of plastic waste. In this study, we developed a multi-stimuli-responsive photocatalytic polymer degradation system facilitated by the photocatalysis of a polyoxometalate [γ-PV2W10O40]5- in conjunction with chloride ions (Cl-) as harmless and abundant stimuli. The degradation of various polymers was significantly accelerated in the presence of Cl-, which was attributed to the oxidation of Cl- by the polyoxometalate photocatalysis into a highly reactive chlorine radical that can efficiently generate a carbon-centered radical for subsequent polymer degradation. Although organic and organometallic photocatalysts decomposed under the conditions for photocatalytic polymer degradation in the presence of Cl-, [γ-PV2W10O40]5- retained its structure even under these highly oxidative conditions.

Ultra-stable and highly reactive colloidal gold nanoparticle catalysts protected using multi-dentate metal oxide nanoclusters.

Owing to their remarkable properties, gold nanoparticles are applied in diverse fields, including catalysis, electronics, energy conversion and sensors. However, for catalytic applications of colloidal gold nanoparticles, the trade-off between their reactivity and stability is a significant concern. Here we report a universal approach for preparing stable and reactive colloidal small (~3 nm) gold nanoparticles by using multi-dentate polyoxometalates as protecting agents in non-polar solvents. These nanoparticles exhibit exceptional stability even under conditions of high concentration, long-term storage, heating and addition of bases. Moreover, they display excellent catalytic performance in various oxidation reactions of organic substrates using molecular oxygen as the sole oxidant. Our findings highlight the ability of inorganic multi-dentate ligands with structural stability and robust steric and electronic effects to confer stability and reactivity upon gold nanoparticles. This approach can be extended to prepare metal nanoparticles other than gold, enabling the design of novel nanomaterials with promising applications.

Porphyrin-Polyoxotungstate Molecular Hybrid as a Highly Efficient, Durable, Visible-Light-Responsive Photocatalyst for Aerobic Oxidation Reactions.

Organic-polyoxometalate (POM) hybrids have recently attracted considerable interest because of their distinctive properties and wide-ranging applications. For the construction of organic-POM hybrids, porphyrins are promising building units owing to their optical properties and reactivity, including strong visible-light absorption and subsequent singlet-oxygen (1O2*) generation. However, the practical utilization of porphyrins as photocatalysts and photosensitizers is often hindered by their own degradation by 1O2*. Therefore, there is a substantial demand for the development of porphyrin-derived photocatalysts with both high efficiency and durability. Herein, we present a porphyrin-polyoxotungstate molecular hybrid featuring a face-to-face stacked porphyrin dimer (I) fastened by four lacunary polyoxotungstates. Hybrid I exhibited remarkable efficiency and durability in photocatalytic aerobic oxidation reactions, and the selective oxidation of various dienes, alkenes, sulfides, and amines proceeded using just 0.003 mol % of the catalyst. Mechanistic investigations suggested that the high activity of I stems from the efficient generation of 1O2*, resulting from the heavy-atom effect of POMs. Furthermore, despite its high efficiency in 1O2* generation compared to free porphyrins, I exhibited superior durability against 1O2*-induced degradation under photoirradiation.

Heterogeneously catalyzed decarbonylation of thioesters by supported Ni, Pd, or Rh nanoparticle catalysts.

Decarbonylation of thioesters has been actively studied using homogeneous metal catalysts as an attractive approach for synthesizing thioethers, which are widely utilized in various fields, because decarbonylation ideally requires no additives and produces CO as the sole theoretical byproduct. However, heterogeneously catalyzed decarbonylation of thioesters has not been reported to date, despite its importance for the construction of environmentally-friendly and practical catalytic systems. This study demonstrated a heterogeneously catalyzed system for the decarbonylation of various aryl thioesters to produce thioethers and CO by utilizing CeO2- or hydroxyapatite-supported Ni, Pd, or Rh nanoparticle catalysts. The Ni catalysts showed high catalytic activity, while the Pd catalysts possessed excellent functional group tolerance. The Rh catalysts were suitable for the selective decarbonylation of unsymmetrically substituted thioesters.

Molecular hybrids of trivacant lacunary polyoxomolybdate and multidentate organic ligands.

Functional molecular inorganic-organic hybrids of lacunary polyoxometalates and organic ligands attract much attention for advanced material applications. However, the inherent instability of lacunary polyoxomolybdates hinders the synthesis of hybrids and their utilization. Herein, we present a viable approach for the synthesis of molecular hybrids of trivacant lacunary Keggin-type polyoxomolybdates and multidentate organic ligands including carboxylates and phosphonates, which is based on the use of a lacunary structure stabilized by removable pyridyl ligands as a starting material.

Highly efficient degradation of polyesters and polyethers by decatungstate photocatalysis.

Photocatalytic polymer degradation has been recognized as a promising solution to the global disposal of waste plastics. In this work, we revealed that various polyesters and polyethers were efficiently degraded in the presence of a polyoxometalate photocatalyst, specifically, decatungstate ([W10O32]4-, W10). A catalytic amount of W10 initiated the degradation of various polyesters and polyethers under photo-irradiation with a xenon lamp (λ > 350 nm) using O2 (1 atm) as the oxidant in acetonitrile or water. Moreover, this system can promote polymer degradation even under sunlight. The degradation efficiency, assessed from the degradation rate (Mw0 - Mw)/Mw0 (%) (where Mw0 is the Mw before the reaction), of W10 was notably higher than those of previously reported photocatalysts such as titanium oxide, other polyoxometalates, organometallic compounds, and organic dyes.