Publications by authors named "Toshihiko Yokoyama"

Background: ()-mutant non-small-cell lung cancers (NSCLCs) have higher frequencies of bone metastases than those of wild type; however, the metastatic pattern and influence on clinical outcome remain unclear.

Objectives: To analyze the association between bone metastatic sites and the clinical efficacy of the first-, second-, and third-generation EGFR-tyrosine kinase inhibitors (TKI), in these patients.

Design: Retrospective multicenter cohort study.

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Introduction: Necitumumab plus gemcitabine and cisplatin (GCN) is a standard therapy for patients with advanced lung squamous cell carcinoma (LSqCC). However, the efficacy and tolerability of GCN in second-line or later treatment for patients previously treated with immune checkpoint inhibitors (ICIs) remain unknown.

Methods: This multicenter, retrospective, cohort study assessed the efficacy and tolerability of GCN initiated between November 1, 2019 and March 31, 2022 as second-line to fourth-line treatment in patients with advanced LSqCC who had been pretreated with ICIs.

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We herein report a case of recurrent infection caused by Verruconis gallopava, which is known to cause fatal phaeohyphomycosis. A 71-year-old man presented with a fever, and computed tomography revealed right chest wall thickening. Eleven years earlier, he had undergone autologous peripheral blood stem cell transplantation for a hematological malignancy.

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Purpose:  Less-invasive early diagnosis of lung cancer is essential for improving patient survival rates. The purpose of this study is to demonstrate that serum comprehensive miRNA profile is high sensitive biomarker to early-stage lung cancer in direct comparison to the conventional blood biomarker using next-generation sequencing (NGS) technology combined with automated machine learning (AutoML).

Methods: We first evaluated the reproducibility of our measurement system using Pearson's correlation coefficients between samples derived from a single pooled RNA sample.

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We recently found that [Pt(CO)(PPh)] (Pt = platinum; CO = carbon monoxide; PPh = triphenylphosphine; = 1+ or 2+) is a Pt nanocluster (Pt NC) that can be synthesized with atomic precision in air. The present study demonstrates that it is possible to prepare a Pt-supported carbon black (CB) catalyst (Pt/CB) with 2.1 times higher oxygen reduction reaction (ORR) activity than commercial Pt nanoparticles/CB by the adsorption of [Pt(CO)(PPh)] onto CB and subsequent calcination of the catalyst.

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Nature of the metallic bond and thermal vibration in brass alloy is investigated from the local structural and thermodynamical points of view by the temperature-dependent Cu and Zn K-edge extended X-ray absorption fine structure spectroscopy and the path-integral effective classical potential theoretical simulation. It is unexpectedly found that the thermal vibrational amplitude around Zn is a little but meaningfully smaller than that around Cu, although it is usually believed that Zn is a much softer metal than Cu in terms of various thermodynamical physical quantities of elemental metals. Moreover, it is found that the nearest neighbor distance around Zn is almost equivalent to that around Cu (only ∼0.

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Background: Osimertinib-the third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI)-has been widely used as a first-line treatment for patients with metastatic EGFR-mutant non-small cell lung cancer (NSCLC). Osimertinib demonstrated central nervous system activity in patients with brain metastasis; however, its efficacy against other distant metastatic organs, including bone and liver, remains unclear. Therefore, we retrospectively analyzed the clinical efficacy of osimertinib in these patients in comparison to other EGFR-TKIs.

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Copper tungstate (CuWO) is an important semiconductor with a sophisticated and debatable electronic structure that has a direct impact on its chemistry. Using the PAL-XFEL source, we study the electronic dynamics of photoexcited CuWO. The Cu L X-ray absorption spectrum shifts to lower energy upon photoexcitation, which implies that the photoexcitation process from the oxygen valence band to the tungsten conduction band effectively increases the charge density on the Cu atoms.

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We have investigated the S adsorption behaviours on Pt (average particle diameter of ∼2.6 nm) and PtCo (∼3.0 nm) anode and cathode electrode catalysts in polymer electrolyte fuel cells (PEFCs) under working conditions for the fresh state just after the aging process and also the degraded state after accelerated degradation tests (ADT), by studying near ambient pressure hard X-ray photoelectron spectroscopy (HAXPES).

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Favipiravir is an oral broad-spectrum inhibitor of viral RNA-dependent RNA polymerase that is approved for treatment of influenza in Japan. We conducted a prospective, randomized, open-label, multicenter trial of favipiravir for the treatment of COVID-19 at 25 hospitals across Japan. Eligible patients were adolescents and adults admitted with COVID-19 who were asymptomatic or mildly ill and had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

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Negative thermal expansion (NTE) is an intriguing property for not only fundamental studies but also technological applications. However, few NTE materials are available compared with the huge amount of positive thermal expansion materials. The discovery of new NTE materials remains challenging.

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The ceria-based catalyst incorporated with Cr and a trace amount of Rh (CrRhCeO) was prepared and the reversible redox performances and oxidation catalysis of CO and alcohol derivatives with O at low temperatures (<373 K) were investigated. In situ X-ray absorption fine structure (XAFS), ambient-pressure X-ray photoelectron spectroscopy (AP-XPS), high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM)-EDS/EELS and temperature-programmed reduction/oxidation (TPR/TPO) revealed the structures and redox mechanisms of three metals in CrRhCeO: dispersed Rh species (<1 nm) and CrO nanoparticles (∼1 nm) supported on CeO in CrRhCeO were transformed to Rh nanoclusters, Cr(OH) species and CeO with two Ce-oxide layers at the surface in a concerted activation manner of the three metal species with H.

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Understanding the excited state of photocatalysts is significant to improve their activity for water splitting reaction. X-ray absorption fine structure (XAFS) spectroscopy in X-ray free electron lasers (XFEL) is a powerful method to address dynamic changes in electronic states and structures of photocatalysts in the excited state in ultrafast short time scales. The ultrafast atomic-scale local structural change in photoexcited WO was observed by W L edge XAFS spectroscopy using an XFEL.

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We designed and constructed a beamline BL36XU at the 8 GeV synchrotron radiation facility SPring-8 to provide information required for the development of next-generation polymer electrolyte fuel cells (PEFCs) by clarifying the dynamic aspects of structures and electronic states of cathode catalysts under PEFC operating conditions and in the deterioration processes by accelerated durability test protcols. To investigate the mechanism and degradation process for the cathode electrocatalysis in practical PEFCs, we developed advanced time- and spatially-resolved in-situ/operando X-ray absorption fine structure measurement systems and complementary analytical systems (X-ray emission spectroscopy (XES), X-ray diffraction (XRD), X-ray computer tomography (CT) and hard X-ray photoelectron spectroscopy (HAXPES)) and combined them to develop multi-analytical systems at BL36XU. Multi-analytical systems are very powerful for observing spatial-temporal features of the transient processes occurring in complex systems such as PEFCs.

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The robust bonding between Fe and N atoms has the potential to fabricate a ferromagnetic FeN monolayer of a square lattice independently of the symmetry of the substrate. The electronic and magnetic properties tuned by the symmetry of the substrates are investigated by comparing the results of scanning tunnel microscopy and x-ray absorption spectroscopy/magnetic circular dichroism of the square FeN monolayer on the Cu(1 1 1) substrate with that on the Cu(0 0 1) substrate. A periodic electronic modulation of the FeN monolayer on the Cu(1 1 1) substrate is induced by the stripe superlattice due to the difference of the lattice symmetry between the FeN monolayer and the Cu(1 1 1) substrate.

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Aims: It was recently reported that lactate acts as a metabolic mediator and rises in the diabetic state, but the physiological effects are as yet poorly understood. The objective of the current study was to evaluate the significance of serum lactate elevation in type 2 diabetes mellitus (T2DM) patients.

Methods: Fasting serum lactate levels, hematological and inflammatory serum markers and anthropometric parameters, obtained employing bioelectric impedance analysis, were measured in 103 patients with T2DM.

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X-ray two-photon absorption (TPA) spectrum of metallic copper is measured using a free-electron laser (XFEL). The spectrum differs from that measured by the conventional one-photon absorption (OPA), and characterized by a peak below the Fermi level, which is assigned to the transition to the 3d state. The impact of the XFEL pulse on the OPA spectrum is discussed by analyzing the pulse-energy dependence, which indicates that the intrinsic TPA spectrum is measured.

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Surface fluorescence X-ray absorption fine structure (XAFS) spectroscopy using a Laue-type monochromator has been developed to acquire structural information about metals with a very low concentrate on a flat highly oriented pyrolytic graphite (HOPG) surface in the presence of electrolytes. Generally, surface fluorescence XAFS spectroscopy is hindered by strong scattering from the bulk, which often chokes the pulse counting detector. In this work, we show that a bent crystal Laue analyzer (BCLA) can efficiently remove the scattered X-rays from the bulk even in the presence of solution.

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Heterogeneous interfaces play important roles in a variety of functional material systems and technologies, such as catalysis, batteries, and devices. A fundamental understanding of efficient functions at interfaces under realistic conditions is crucial for sophisticated designs of useful material systems and novel devices. X-ray photoelectron spectroscopy is one of the most promising and common methods to investigate such material systems.

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Photoelectron spectroscopy has the advantage of providing electric potentials by non-contact measurements based on the kinetic energy shift in component potential. We performed operando hard X-ray photoelectron spectroscopy (HAXPES) measurements with an 8 keV excitation source to measure the shift in electron kinetic energies as a function of the voltages of all the components at the anode and cathode electrodes of a polymer electrolyte fuel cell (PEFC). At the cathode electrode, when we increase the voltage between the cathode and anode from 0.

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Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures.

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Ultrafast excitation of photocatalytically active BiVO was characterized by femto- and picosecond transient X-ray absorption fine structure spectroscopy. An initial photoexcited state (≪500 fs) changed to a metastable state accompanied by a structural change with a time constant of ∼14 ps. The structural change might stabilize holes on oxygen atoms since the interaction between Bi and O increases.

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Self-assembled organic molecules can potentially be an excellent source of charge and spin for two-dimensional (2D) atomic-layer superconductors. Here we investigate 2D heterostructures based on In atomic layers epitaxially grown on Si and highly ordered metal-phthalocyanine (MPc, M = Mn, Cu) through a variety of techniques: scanning tunneling microscopy, electron transport measurements, angle-resolved photoemission spectroscopy, X-ray magnetic circular dichroism, and ab initio calculations. We demonstrate that the superconducting transition temperature (T) of the heterostructures can be modified in a controllable manner.

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We performed in situ hard X-ray photoelectron spectroscopy (HAXPES) measurements of the electronic states of platinum nanoparticles on the cathode electrocatalyst of a polymer electrolyte fuel cell (PEFC) using a near ambient pressure (NAP) HAXPES instrument having an 8 keV excitation source. We successfully observed in situ NAP-HAXPES spectra of the Pt/C cathode catalysts of PEFCs under working conditions involving water, not only for the Pt 3d states with large photoionization cross-sections in the hard X-ray regime but also for the Pt 4f states and the valence band with small photoionization cross-sections. Thus, this setup allowed in situ observation of a variety of hard PEFC systems under operating conditions.

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Unique thermal properties of metal clusters are believed to originate from the hierarchy of the bonding. However, an atomic-level understanding of how the bond stiffnesses are affected by the atomic packing of a metal cluster and the interfacial structure with the surrounding environment has not been attained to date. Here we elucidate the hierarchy in the bond stiffness in thiolate-protected, icosahedral-based gold clusters Au25(SC2H4Ph)18, Au38(SC2H4Ph)24 and Au144(SC2H4Ph)60 by analysing Au L3-edge extended X-ray absorption fine structure data.

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