Publications by authors named "Ohkubo K"

Considering the demand for organosulfur materials and the challenges associated with currently used oxidation processes, in this study, we evaluated the counter-cation of sodium chlorite (Na+ClO2-) with tetrabutylammonium chloride (Bu4N+Cl-) to synthesise tetrabutylammonium chlorite (Bu4N+ClO2-). Bu4N+ClO2- exhibited good solubility in organic solvents like chloroform (1.6 g mL-1) and ethyl acetate (0.

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Aims: Direct oral anticoagulants (DOACs) are used to treat venous thromboembolism (VTE). However, their impact on thrombus regression and the clinical outcomes after 2-week post-therapy computed tomography (CT) monitoring remains unexplored. This study aimed to elucidate the characteristics of patients with VTE treated with individual DOACs, assess the incidence of clinical events, and evaluate their impact on pulmonary artery thrombus regression.

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Protein trafficking to vacuoles in plants and fungi, and to lysosomes in animals, is essential for the maintenance of cellular homeostasis. In Saccharomyces cerevisiae, the vacuolar protein sorting (VPS) pathway has been well studied by using vacuolar carboxypeptidase Y (CPY) as a model, and many VPS genes have been identified. By contrast, the vacuolar protein trafficking pathway in Schizosaccharomyces pombe remains poorly understood.

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Planar catechin (PCat), a natural antioxidant with a fixed 3D catechin structure on a plane, exhibits radical-scavenging activity approximately five times stronger than the conventional catechin. We synthesized a compound, PCat-TrOH, by binding Trolox (TrOH), an α-tocopherol analog, to PCat to enhance its antioxidant effect against oxidative stress, such as lipid peroxidation. TrOH shows radical-scavenging activity about 6.

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Recent studies have highlighted the indispensable role of oxidized lipids in inflammatory responses, cell death, and disease pathogenesis. Consequently, inhibitors targeting oxidized lipids, particularly lipid-derived radicals critical in lipid peroxidation, which are known as radical-trapping antioxidants (RTAs), have been actively pursued. We focused our investigation on nitroxide compounds that have rapid second-order reaction rate constants for reaction with lipid-derived radicals.

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2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO), a persistent nitronyl nitroxide radical, has been used for the detection and trapping of nitric oxide, as a redox mediator for batteries, for the activity estimation of antioxidants, and so on. However, there is no report on the reactivity of PTIO in the presence of redox-inactive metal ions. In this study, it is demonstrated that the addition of scandium triflate, Sc(OTf) (OTf = OSOCF), to an acetonitrile (MeCN) solution of PTIO resulted in an electron-transfer disproportionation to generate the corresponding cation (PTIO) and anion (PTIO), the latter of which is suggested to be stabilized by Sc to form [(PTIO)Sc].

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Context: Thyroglobulin (Tg), encoded by TG, is essential for thyroid hormone synthesis. TG defects result in congenital hypothyroidism (CH). Most reported patients were born before the introduction of newborn screening (NBS).

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Questions about which reactive oxygen species (ROS) or reactive nitrogen species (RNS) can escape from the mitochondria and activate signals must be addressed. In this study, two parameters, the calculated dipole moment (debye, D) and permeability coefficient (Pm) (cm s), are listed for hydrogen peroxide (HO), hydroxyl radical (•OH), superoxide (O), hydroperoxyl radical (HO•), nitric oxide (•NO), nitrogen dioxide (•NO), peroxynitrite (ONOO), and peroxynitrous acid (ONOOH) in comparison to those for water (HO). O is generated from the mitochondrial electron transport chain (ETC), and several other ROS and RNS can be generated subsequently.

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Article Synopsis
  • The study focuses on creating two-dimensional materials, highlighting their promising capabilities.
  • Researchers successfully made a nanosheet using amphiphilic Rose Bengal dyes in water.
  • They found that forming this nanosheet led to a notable change in how the material interacts with light during photosensitization.
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The Ibaraki virus (IBAV) causes Ibaraki disease in cattle. Our previous studies have shown that IBAV uses macropinocytosis to enter the host cell and exit from the endosome to the cytosol in response to endosomal acidification. To further explore the mechanism of IBAV infection and replication, we examined the effect of inhibitors of mitochondrial oxidative phosphorylation, carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and antimycin A, on IBAV propagation.

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Introduction: High-power short-duration (HPSD) ablation at 50 W, guided by ablation index (AI) or lesion size index (LSI), and a 90 W/4 s very HSPD (vHPSD) setting are available for atrial fibrillation (AF) treatment. Yet, tissue temperatures during ablation with different catheters around venoatrial junction and collateral tissues remain unclear.

Methods: In this porcine study, we surgically implanted thermocouples on the epicardium near the superior vena cava (SVC), right pulmonary vein, and esophagus close to the inferior vena cava.

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Caged compounds protected with photolabile protecting groups (PPGs) are useful for controlling various biological events with high spatiotemporal resolution. Most of the commonly used PPGs are controlled by ultraviolet light irradiation, but it is desirable to have PPGs controlled by visible light irradiation in order to minimize tissue damage. Here, we describe a boron-dipyrromethene (BODIPY)-picolinium conjugate (BPc group) that functions as a blue-light-controllable PPG.

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A neutral, stable radical, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), has been frequently used to estimate the activity of antioxidants for more than 60 years. However, the number of reports about the effect of metal ions on the reactivity of DPPH is quite limited. We have recently reported a unique electron-transfer disproportionation of DPPH to produce the DPPH cations (DPPH) and anions (DPPH) upon the addition of scandium triflate [Sc(OTf) (OTf = OSOCF)] to an acetonitrile (MeCN) solution of DPPH.

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In this study, we examined the modification of polypropylene non-woven fabrics (PP NWFs) a one-step oxidation treatment using photo-activated chlorine dioxide radicals (ClO˙). The oxidised PP NWFs exhibited excellent antibacterial activity against both (Gram-negative) and (Gram-positive). The mound structure and antibacterial activity in the modified PP NWFs disappeared upon washing with a polar organic solvent.

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The oxygenation of C(sp)-H bonds is a key chemical reaction in the production of fine chemicals and pharmaceuticals. Hydrogen atom transfer has recently gained significant attention for its ability to functionalise C-H bonds. The C-H bond can be activated by transferring the H radical to a hydrogen acceptor such as the chlorine radical (Cl˙).

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Article Synopsis
  • α-Klotho is a protein linked to longevity, and its deficiency in mice leads to reduced lifespan and significant muscle deterioration.
  • Loss of circulating α-Klotho correlates with increased activation of Smad2, which is involved in aging-related muscle wasting caused by TGF-β factors.
  • Treatment with a small-molecule inhibitor, Ki26894, shows promise in reversing muscle atrophy and enhancing muscle fiber type in aged mice, suggesting a potential therapeutic approach to combat age-related muscle loss.
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Introduction: Neither the actual in vivo tissue temperatures reached with 90 W/4 s-very high-power short-duration (vHPSD) ablation for atrial fibrillation nor the safety and efficacy profile have been fully elucidated.

Methods: We conducted a porcine study (n = 15) in which, after right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We compared tissue temperatures close to a QDOT MICRO catheter, between during 90 W/4 s-vHPSD ablation during ablation index (AI: target 400)-guided 50 W-HPSD ablation, both targeting a contact force of 8-15 g.

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Chlorocarboxylation of toluene was achieved by photoirradiation of a chlorine dioxide radical (ClO˙) under ambient conditions (298 K and 1 atm). 2- and 4-Chlorobenzoic acids were obtained in a 1 : 1 yield ratio. This is a single step synthesis under metal-free and mild conditions.

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Background: Neither the actual in vivo tissue temperatures reached with lesion size index (LSI)-guided high-power short-duration (HPSD) ablation for atrial fibrillation nor the safety profile has been elucidated.

Methods: We conducted a porcine study (n = 7) in which, after right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We compared tissue temperatures reached during 50 W-HPSD ablation with those reached during standard (30 W) ablation, both targeting an LSI of 5.

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Antibody-mimetic drug conjugate is a novel noncovalent conjugate consisting of an antibody-mimetic recognizing a target molecule on the cancer cell surface and low-molecular-weight payloads that kill the cancer cells. In this study, the efficacy of a photo-activating antibody-mimetic drug conjugate targeting HER2-expressing tumors was evaluated in mice, by using the affibody that recognize HER2 (Z ) as a target molecule and an axially substituted silicon phthalocyanine (a novel potent photo-activating compound) as a payload. The first treatment with the photo-activating antibody-mimetic drug conjugates reduced the size of all HER2-expressing KPL-4 xenograft tumors macroscopically.

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Article Synopsis
  • Extremely low levels of alanine aminotransferase (ALT) in patients with atrial fibrillation (AF) may indicate underlying issues like aging, malnutrition, and frailty, but the connection to mortality rates hasn't been well studied.
  • In a study involving over 3,000 patients with nonvalvular AF, those with very low ALT levels (≤15 U/L) were older and had worse health markers, including lower BMI and higher rates of heart failure.
  • During follow-up, patients in the lowest ALT group experienced significantly higher rates of cardiovascular and all-cause mortality, highlighting low ALT as a potential indicator of higher mortality risk in AF patients, even after accounting for other health factors.
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We found that -nitrosoaminoanisole derivatives tethered to dyes work as photocontrollable nitrosonium cation releasers and are converted to potent nitric oxide releasers in the presence of sodium ascorbate. The -nitrosoaminoanisole derivative 2 worked as a more potent photovasodilating reagent than previously reported nitric oxide releasers.

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Photosensitizers (PSs) are critical substances with considerable potential for use in non-invasive photomedicine. Type I PSs, which generate reactive radical species by electron transfer from the excited state induced via photoirradiation, attracted much attention because of their suitability for photodynamic therapy (PDT) irrespective of the oxygen concentration. However, most organic PSs are type II, which activates only oxygen, generating singlet oxygen (O) via energy transfer from the triplet state.

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Visible-light-induced decarboxylative and deboronative reactions using two-molecule organic photoredox catalysts, namely, phenanthrene (Phen) and biphenyl (BP), as electron donors and 9-cyano-10-methoxycarbonylanthracene as an electron acceptor were achieved. The high solubility of significantly improved the reaction efficiency and product yield. In addition, the facile tuning of the oxidation potential of the electron-donor molecule via the replacement of Phen with BP enabled the application of the two-molecule photoredox system to a wide range of substrates.

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We report the visible-light-induced preparation of COCl through the oxygenation of chloroform in the presence of chlorine dioxide, which leads to the safe constructions of carbamoyl chlorides with good-to-high yields and wide substrate scopes. In addition, this method can also be applied to the synthesis of various carbonates.

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