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.

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.

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.

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.

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.

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 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.

[A Case of Specific Pneumonia Diagnosed as Peritumoral Infiltration during Nivolumab Treatment for Esophageal Cancer].

The patient is a 54-year-old man who was diagnosed with advanced unresectable esophageal cancer. He underwent three courses of FP therapy and was followed up for observation after chemoradiotherapy and PR. Metastasis appeared in the upper lobe of the left lung and new lung metastasis was found in the lower lobe of the right lung despite FP therapy 2 years and 1 month after the start of treatment. Nedaplatin and docetaxel were administered as a second-line chemotherapy; however, the lung metastasis worsened. Consequently, nivolumab was introduced as a third-line chemotherapy. The metastases in the lower lobe of the right lung disappeared with pneumonia after 6 courses of nivolumab, which was diagnosed as a peritumoral infiltration(PTI). PTI is difficult to distinguish from drug-induced lung injury and should be diagnosed carefully because it is an imaging finding that reflects the desired antitumor effect.

Recent Advances in Hybrid Materials of Metal Nanoparticles and Polyoxometalates.

Polyoxometalates (POMs), anionic metal-oxygen nanoclusters that possess various composition-dependent properties, are widely used to modify the existing properties of metal nanoparticles and to endow them with new ones. Herein, we present an overview of recent advances in hybrid materials that consist of metal nanoparticles and POMs. Following a brief introduction on the inception of this area and its development, representative properties and applications of these materials in various fields such as electrochemistry, photochemistry, and catalysis are introduced. We discuss how the combination of two classic inorganic materials facilitates cooperative and synergistic behavior, and we also give personal perspectives on the future development of this field.

Nanostructured Manganese Oxides within a Ring-Shaped Polyoxometalate Exhibiting Unusual Oxidation Catalysis.

Nanosized manganese oxides have recently received considerable attention for their synthesis, structures, and potential applications. Although various synthetic methods have been developed, precise synthesis of novel nanostructured manganese oxides are still challenging. In this study, using a structurally defined nanosized cavity inside a ring-shaped polyoxometalate, we succeeded in synthesizing two types of discrete 18 and 20 nuclear nanostructured manganese oxides, Mn18 and Mn20, respectively. In particular, Mn18 showed much higher catalytic activity than other manganese oxides for the oxygenation of alkylarenes including electron-deficient ones, and the reaction proceeded through a unique reaction mechanism due to its unusual manganese oxide structure.

Ligand-Protecting Strategy for the Controlled Construction of Multinuclear Copper Cores within a Ring-Shaped Polyoxometalate.

The ring-shaped polyoxometalate (POM) [P8W48O184]40- contains a large cavity and is an attractive inorganic multidentate ligand for accumulating metal cations. Until now, several multinuclear metal cores are constructed within the {P8W48} framework in aqueous solvents. However, it is still challenging to control the number and arrangement of introduced metal cations because of the numerous coordination sites inside the {P8W48} framework. In this study, we developed a novel approach for the selective synthesis of several multinuclear copper-containing ring-shaped POMs in organic solvents using methoxy groups as organic protecting ligands for the reactive coordination sites. Reacting a tetra-n-butylammonium (TBA) salt of [P8W48O184]40- (P8W48) with 4 and 8 equiv of copper(II) acetate in the presence of methanol (MeOH), tetra- and octacopper cores were incorporated into the cavity to form TBA11H13[Cu4(H2O)4P8W48O176(OCH3)8]·28H2O·3CH3NO2 (Cu4) and TBA14H2[Cu8(H2O)12P8W48O176(OCH3)8]·24H2O·CH3CN (Cu8), respectively. For both structures, methoxy groups served as protecting ligands and temporarily inactivated vacant coordination sites. Without MeOH, dodeca- and hexadecacopper cores were constructed inside the cavity to form TBA14H2[Cu12(H2O)16P8W48O184]·4H2O (Cu12) and TBA16H8[Cu16(OH)16(H2O)4P8W48O184]·12H2O·C3H6O (Cu16), respectively. The arrangement of copper ions on the same {P2W12} units could be controlled by the input number of copper ions. Moreover, all four POMs could be synthesized from P8W48 by the stepwise addition of 4 equiv of copper(II) acetate, clarifying the introduction process.

Development and evaluation of a double-check support system using artificial intelligence in endoscopic screening for gastric cancer.

BACKGROUND: This study aimed to prevent missing gastric cancer and point out low-quality images by developing a double-check support system (DCSS) for esophagogastroduodenoscopy (EGD) still images using artificial intelligence. METHODS: We extracted 12,977 still EGD images from 855 cases with cancer [821 with early gastric carcinoma (EGC) and 34 malignant lymphoma (ML)] and developed a lesion detection system using 10,994 images. The remaining images were used as a test dataset. Additional validation was performed using a new dataset containing 50 EGC and 1,200 non-GC images by comparing the interpretation of ten endoscopists (five trainees and five experts). Furthermore, we developed another system to detect low-quality images, which are not suitable for diagnosis, using 2198 images. RESULTS: In the validation of 1983 images from the 124 cancer cases, the DCSS diagnosed cancer with a sensitivity of 89.2%, positive predictive value (PPV) of 93.3%, and an accuracy of 83.3%. EGC was detected in 93.2% and ML in 92.5% of cases. Comparing with the endoscopists, sensitivity was significantly higher in the DCSS, and the average diagnostic time was significantly shorter using the DCSS than that by the trainees. The sensitivity, specificity, PPV, and accuracy in detecting low-quality images were 65.8%, 93.1%, 79.6%, and 85.2% for "Blur" and 57.8%, 91.7%, 82.2%, and 78.1% for "Mucus adhesion," respectively. CONCLUSIONS: The DCSS showed excellent capability in detecting lesions and pointing out low-quality images.

Supported Anionic Gold Nanoparticle Catalysts Modified Using Highly Negatively Charged Multivacant Polyoxometalates.

Although supported anionic gold nanoparticle catalysts have been theoretically investigated for their efficacy in activating O2 in aerobic oxidation reactions, limited studies have been reported due to the difficulty of designing these catalysts. Herein, we developed a feasible method for preparing supported anionic gold nanoparticle catalysts using multivacant lacunary polyoxometalates with high negative charges. We confirmed the strong and robust electronic interaction between gold nanoparticles and multivacant lacunary polyoxometalates, and the electronic states of the supported gold nanoparticle catalysts can be sequentially modulated. Particularly, the catalyst prepared using [SiW9 O34 ]10- acted as an efficient reusable heterogeneous catalyst, showing superior catalytic performance for the oxidative dehydrogenation of piperidone derivatives to the corresponding enaminones and remarkably higher stability than supported gold nanoparticle catalysts without this modification.

Robotic Stepwise Synthesis of Hetero-Multinuclear Metal Oxo Clusters as Single-Molecule Magnets.

An efficient stepwise synthesis method for discovering new heteromultinuclear metal clusters using a robotic workflow is developed where numerous reaction conditions for constructing heteromultinuclear metal oxo clusters in polyoxometalates (POMs) were explored using a custom-built automated platform. As a result, new nonanuclear tetrametallic oxo clusters {FeMn4}Lu2A2 in TBA5[(A-α-SiW9O34)2FeMn4O2{Lu(acac)2}2A2] (IIA; A = Ag, Na, K; TBA = tetra-n-butylammonium; acac = acetylacetonate) were discovered by the installation of diamagnetic metal cations A+ into a paramagnetic {FeMn4}Lu2 unit in TBA7[(A-α-SiW9O34)2FeMn4O2{Lu(acac)2}2] (I). POMs IIA exhibited single-molecule magnet properties with the higher energy barriers for magnetization reversal (IIAg, 40.0 K; IINa, 40.3 K; IIK, 26.7 K) compared with that of the parent I (19.7 K). Importantly, these clusters with unique properties were constructed as designed by a step of the predictable sequential multistep reactions with the time-efficient platform.

Ligand-Directed Approach in Polyoxometalate Synthesis: Formation of a New Divacant Lacunary Polyoxomolybdate [γ-PMo10 O36 ]7.

Polyoxometalates (POMs) have received increasing attention over the last decades for extending their application and properties that originate from novel structures. For the synthesis of a variety of POM structures, multivacant lacunary POMs are key precursors, which are typically synthesized by empirically controlling the complex equilibrium in aqueous solvents. Unfortunately, despite the excellent catalytic and electrochemical properties of "polyoxomolybdates", only one multivacant lacunary species, i.e., [A-α-PMo9 O34 ]9- , has been identified and isolated because multivacant lacunary polyoxomolybdates are typically unstable. Here we report a ligand-directed approach for the selective formation of an unprecedented lacunary polyoxomolybdate in organic solvents. By structure transformation of a pyridine-coordinated [A-α-PMo9 O34 ]9- , a new γ-Keggin-type divacant lacunary polyoxomolybdate [γ-PMo10 O36 ]7- was obtained, which can be further used as a precursor for synthesizing a POM-organic hybrid.

A Molecular Hybrid of an Atomically Precise Silver Nanocluster and Polyoxometalates for H2 Cleavage into Protons and Electrons.

Atomically precise silver (Ag) nanoclusters are promising materials as catalysts, photocatalysts, and sensors because of their unique structures and mixed-valence states (Ag+ /Ag0 ). However, their low stability hinders the in-depth study of their intrinsic reactivity and catalytic property accompanying their redox processes. Herein, we demonstrate that a molecular hybrid of an atomically precise {Ag27 }17+ nanocluster and polyoxometalates (POMs) can efficiently cleave H2 into protons and electrons. The Ag nanocluster accommodates electrons through the redox reaction from {Ag27 }17+ to {Ag27 }13+ , and the POM ligands play the following important roles: (i) a significant stabilization of the typically unstable Ag nanocluster to preserve its structure during the redox reaction with H2 , (ii) formation of a unique interface between the Ag nanocluster and metal oxides for efficient H2 cleavage, and (iii) storage of the generated protons on the negatively charged basic surface.

p53/Mieap-regulated mitochondrial quality control plays an important role as a tumor suppressor in gastric and esophageal cancers.

Mitochondria-eating protein (Mieap) plays a critical role in mitochondrial quality control (MQC) and functions as a p53-inducible tumor suppressor. This study aimed to examine its role in gastric cancer (GC) and esophageal cancer (EC). GC cells were infected with Mieap-overexpressing adenovirus (Ad-Mieap) and subjected to fluorescence-activated cell sorting (FACS), western blotting, and caspase assays. Thereafter, we evaluated the potential disruption of the p53/Mieap-regulated MQC pathway in vivo. Methylation-specific PCR (MSP) for Mieap, NIX, and BNIP3 promoters was performed and p53 mutations were detected using cryopreserved surgical specimens. Exogenous Mieap in GC cells induced the formation of vacuole-like structures (called MIVs, Mieap-induced vacuoles) and caspase-dependent cell death, with the activation of both caspase-3 and caspase-9. Of the 47 GC patients, promoter methylation in Mieap, BNIP3, and NIX was identified in two (4.3%), 29 (61.7%), and zero (0%) specimens, respectively. In total, 33 GC patients (70.2%) inactivated this MQC pathway. Amazingly, BNIP3 promoter in the normal epithelium was highly methylated in 18 of the 47 GC patients (38.3%). In EC patients, this MQC pathway was also inactivated in ten of 12 patients (83.3%). These results indicate that p53/Mieap-regulated MQC plays an important role in upper gastrointestinal (GI) tumor suppression, possibly, in part, through the mitochondrial apoptotic pathway.

The Impact of Hybrid Minimally Invasive Esophagectomy with Neck-Abdominal First Approach on the Short- and Long-Term Outcomes for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Currently, there is no consensus for an optimal minimally invasive esophagectomy (MIE) approach. This study aimed to compare hybrid MIE (hMIE) with neck-abdominal first approach to standard open esophagectomy (OE). METHODS: Data from a cohort of 301 patients were retrospectively analyzed. All participants received either hMIE or OE for the treatment of esophageal squamous cell carcinoma at Tokyo Medical and Dental University between January 2003 and December 2013. Analyses included propensity score matching and the Kaplan-Meier statistical method to determine overall survival (OS) and disease-free survival (DFS) of the cohort. RESULTS: After one-to-one propensity score matching, there were 68 patient pairs. The hMIE group had significantly lower incidence of severe postoperative complications (20.1% vs. 7.4%; p = 0.026) and severe respiratory complications (7.4% vs. 0%; p = 0.058) than the OE group. The 5-year oncological outcomes of the two groups were almost equivalent (OS: OE, 55.0%; hMIE, 69.0%; p = 0.063 and DFS: OE, 54.0%; hMIE, 62.0%; p = 0.28). CONCLUSIONS: This study compared hMIE with neck-abdominal first approach to standard OE. The results showed significantly less severe postoperative complications for hMIE with neck-abdominal first approach in comparison with OE, without a compromise in long-term oncological outcomes.

Rectal neuroendocrine tumor developing lateral lymph node metastasis after curative resection: a case report.

BACKGROUND: Among gastrointestinal neuroendocrine tumors (NETs), rectal NETs account for about one-third of all tumors. Despite the occasional observation of lateral lymph node metastasis in patients with rectal NETs, lateral lymph node recurrence is rare. We present a rare case of lateral lymph node recurrence after curative resection of a rectal NET. CASE PRESENTATION: A 55-year-old man presented with fecal occult blood and colonoscopy revealed a mass in the distal rectum. Systematic computed tomography scan showed no evidence of regional lymph node or distant metastasis. The patient underwent laparoscopic intersphincteric resection and D2 lymph node dissection with diverting stoma. Diverting stoma closure was performed 6 months after the initial operation. Pathological diagnosis was NET of the rectum, grade 2, T1b, N0, Stage I without lymphovascular invasion. At 54 months after the surgery, recurrence in a left lateral lymph node was suspected and lymph node dissection was performed. The pathological diagnosis of the specimen was consistent with lateral lymph node metastasis of a recurrent rectal NET. To our best knowledge, there are no case reports in English of lateral lymph node recurrence after curative resection of a rectal NET, grade 2, T1b, N0, Stage I without lymphovascular invasion. CONCLUSION: Considering that patients with lateral lymph node metastasis have worse survival than those without metastasis in rectal cancer, if complete resection of the tumor can be achieved for lateral lymph node recurrence, surgery may be an important option in the strategy to treat this condition.

[Hepatic Portal Vein Gas during Chemotherapy for Esophageal Cancer-A Report of Four Cases].

Case 1, a man in his 70s, was admitted because of a bleeding gastric ulcer during DCF therapy for esophageal cancer(EC). Three days after endoscopic hemostasis, abdominal pain and vomiting occurred.CT revealed hepatic portal venous gas (HPVG).No intestinal necrosis was observed on contrast-enhanced CT.Therefore, we selected a conservative treatment and found improvement.Case 2, a man in his 70s, developed frequent diarrhea during DCF therapy for EC.Case 3, a man in his 80s, developed hematochezie during DCF therapy for EC.Both cases 2 and 3 were diagnosed as HPVG using abdominal ultrasonography.The symptoms were mild, so we selected a conservative treatment and found improvement.Case 4, a man in his 60s, noticed sudden severe abdominal pain during DGS therapy for EC.Plain CT detected HPVG and gas in the small intestinal wall.We suspected intestinal necrosis due to HPVG with peritoneal irritation and performed emergency small intestine resection.We encountered 4 patients who developed HPVG during chemotherapy.The presence of HPVG is a poor prognostic sign, suggestive of intestinal necrosis, but some patients show improvement with conservative treatments.We also discuss previous reviews and reports.