Publications by authors named "NAKAYAMA R"

Pulmonary hypertension associated with lung diseases and/or hypoxia is classified as group 3 in the clinical classification of pulmonary hypertension. The efficacy of existing selective pulmonary vasodilators for group 3 pulmonary hypertension is still unknown, and it is currently associated with a poor prognosis. The mechanisms by which pulmonary hypertension occurs include hypoxic pulmonary vasoconstriction, pulmonary vascular remodeling, a decrease in pulmonary vascular beds, endothelial dysfunction, endothelial-to-mesenchymal transition, mitochondrial dysfunction, oxidative stress, hypoxia-inducible factors (HIFs), inflammation, microRNA, and genetic predisposition.

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Background: Chondroblastoma is classified as a benign bone tumor. However, postoperative local recurrence remains a concern. We analyzed the factors contributing to chondroblastoma local recurrence and the clinical challenges associated with treating these patients.

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This study aims to develop a computerized classification method for significant coronary artery stenosis on whole-heart coronary magnetic resonance angiography (WHCMRA) images using a 3D convolutional neural network (3D-CNN) with attention mechanisms. The dataset included 951 segments from WHCMRA images of 75 patients who underwent both WHCMRA and invasive coronary angiography (ICA). Forty-two segments with significant stenosis (luminal diameter reduction 75%) on ICA were annotated on WHCMRA images by an experienced radiologist, whereas 909 segments without it were annotated at representative sites.

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Metasurfaces are artificial thin materials that achieve optical thickness through thin geometrical structure. This feature of metasurfaces results in unprecedented benefits for enhancing the performance of optoelectronic devices. In this study, we report that this metasurface feature is also essential to drive photo-thermoelectric conversion, which requires the accumulation of thermal energy and effective heat conduction.

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  • - Intercalation reactions depend on how the electronic and structural properties of host (like TaS) and guest materials (like divalent ions) interact, making it harder for divalent ions like Mg to intercalate compared to monovalent ions.
  • - This study explores the cointercalation of Mg and hydrogen (H) into TaS to produce bulk polycrystalline MgHTaS, where hydrogen can be removed by heating at around 400 °C without changing the crystal structure.
  • - The research also investigates how the superconducting properties relate to electronic carrier density using both theoretical calculations and experiments, highlighting the benefits of using hydrides for intercalation reactions.
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We investigated potential germline-specific radiosensitive biomarkers in the testes of large Japanese field mice (Apodemus speciosus) exposed to low-dose-rate (LDR) radiation after the Fukushima accident. Fukushima wild mice testes were analysed via RNA-sequencing to identify genes differentially expressed in the breeding and non-breeding seasons when compared to controls. Results revealed significant changes during the breeding season, with Lsp1 showing a considerable upregulation, while Ptprk and Tspear exhibited significant reductions.

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The reading ability of English readers has been shown to correlate with psychophysical measurements of dynamic visual information processing. This study investigated the relationship between reading ability and dynamic visual information processing in healthy adult native Japanese readers (n = 46). Reading ability was assessed using three different tests: the Japanese Adult Reading Test (JART), transposed-letter detection task, and oral reading.

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This study investigates the effect of reduced saliva production on intestinal histological structure and microbiome composition using a sialoadenectomy murine model, evaluating differences in saliva secretion, body weight, intestinal histopathological changes, and microbiome alteration using 16S rRNA gene sequencing across three groups (control, sham, and sialoadenectomy). For statistical analysis, one-way analysis of variance and multiple comparisons using Bonferroni correction were performed. -values < 0.

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Dedifferentiated liposarcoma (DDLPS) comprises a high-grade dedifferentiated (DD) component and a juxtaposed well-differentiated (WD) component. The DD component is believed to originate from the WD component by acquiring additional genomic alterations. In this study, we performed multiregion genome, epigenome, and transcriptome analyses of three patients with DDLPS.

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As compared to peripheral blood mononuclear cell (PBMC) culture, a lower mitotic index (MI) is seen in whole blood (WB) culture, but WB can be directly used for culture in dicentric chromosome assay (DCA). The purpose of this study is to develop a simple protocol for metaphase enrichment to improve the metaphase frequency of WB culture. Fixed cells were obtained after performing WB and PBMC cultures for DCA after conventional fixation.

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We investigate ultrahigh concentration doping of hydrogen (H) into rutile-TiO (100) single crystals by low-energy (2.5 keV) hydrogen ion beam irradiation at low temperature (LT). While the hydrogen concentration was limited to HTiO at 300 K, nuclear reaction analysis (NRA) revealed ultrahigh concentration doping of hydrogen up to HTiO by the LT irradiation at 50 K.

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This study aims to develop an anomaly-detection scheme for lesions in CT images. Our database consists of lung CT images obtained from 1500 examinees. It includes 1200 normal and 300 abnormal cases.

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Introduction: The integration of artificial intelligence (AI) into orthopedics has enhanced the diagnosis of various conditions; however, its use in diagnosing soft-tissue tumors remains limited owing to its complexity. This study aimed to develop and assess an AI-driven diagnostic support system for magnetic resonance imaging (MRI)-based soft-tissue tumor diagnosis, potentially improving accuracy and aiding radiologists and orthopedic surgeons.

Methods: An experienced orthopedic oncologist and radiologist annotated 720 images from 77 cases (41 benign and 36 malignant soft-tissue tumors).

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  • This study analyzes the long-term postoperative outcomes of limb-sparing surgery in children with knee-borne bone sarcoma, focusing on complications and functional results post-surgery.
  • The review included 40 patients under 14 years old and assessed factors like complications, reconstruction success rates, and leg-length discrepancies over a minimum of five years.
  • Key findings indicate that younger age and complications negatively affect functional outcomes, with leg-length discrepancies worsening performance, especially in younger patients.*
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  • - The study aimed to compare washout-parametric imaging (WOPI) and conventional contrast-enhanced ultrasound (cCEUS) in diagnosing focal liver lesions (FLLs).
  • - A total of 181 FLLs were imaged, and results showed no significant difference in diagnostic performance between WOPI and cCEUS, with both techniques yielding similar average AUC values.
  • - WOPI demonstrated better interobserver agreement compared to cCEUS, suggesting it may provide more consistent evaluations among different readers.
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Purpose: This study investigated the breast lesion conspicuity and apparent diffusion coefficient (ADC) reliability for three different diffusion-weighted imaging (DWI) protocols: spatiotemporal encoding (SPEN), single-shot echo-planar imaging (SS-EPI), and readout segmentation of long variable echo-trains (RESOLVE).

Methods: Sixty-five women suspected of having breast tumors were included in this study, with 44 lesions (36 malignant, 8 benign) analyzed further. Breast MRI was performed on a 3 Tesla (3T) system (MAGNETOM Prisma, Siemens) equipped with a dedicated 18-channel breast array coil for a phantom and patients.

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  • Fertility preservation and reproductive treatments in Japan involve significant out-of-pocket expenses for adolescents and young adults, with current healthcare policies lacking in insurance coverage for these services.
  • Patients can apply for government subsidies under specific conditions, but the costs and amounts paid vary by facility.
  • A study conducted with 186 fertility preservation facilities revealed that about one-third of the expenses are shouldered by patients, highlighting the need for improved pricing and insurance options to ensure ongoing access to care.
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Unlabelled: An 82-year-old man with a secundum atrial septal defect (ASD) underwent transcatheter closure. The patient had a wide area of aortic and superior rim deficiency, with left ventricular diastolic dysfunction and moderate mitral regurgitation. These findings suggested the risk of both cardiac erosion and increased left atrial pressure after closure.

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Aims: Although right ventricular (RV) dysfunction is associated with adverse outcomes in tricuspid regurgitation (TR), the potential role of right atrial (RA) function is unknown. We aimed to investigate the relationship between RA function and clinical outcomes in patients with significant TR.

Methods: This retrospective study included 169 outpatients with moderate or severe TR due to left-sided heart diseases who underwent transthoracic echocardiography between June 2020 and April 2023 (average age, 75 ± 10 years; male, 40%).

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Purpose: To evaluate the amide proton transfer (APT), tumor blood flow (TBF), and apparent diffusion coefficient (ADC) combined diagnostic value for differentiating intracranial malignant tumors (MTs) from benign tumors (BTs) in young patients, as defined by the 2021 World Health Organization classification of central nervous system tumors.

Methods: Fifteen patients with intracranial MTs and 10 patients with BTs aged 0-30 years underwent MRI with APT, pseudocontinuous arterial spin labeling (pCASL), and diffusion-weighted imaging. All tumors were evaluated through the use of histogram analysis and the Mann-Whitney U test to compare 10 parameters for each sequence between the groups.

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Normally aerated lung tissue on computed tomography (CT) is correlated with static respiratory system compliance (C) at zero end-expiratory pressure. In clinical practice, however, patients with acute respiratory failure are often managed using elevated PEEP levels. No study has validated the relationship between lung volume and tissue and C at the applied positive end-expiratory pressure (PEEP).

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  • The study examines the differences in patent foramen ovale (PFO) morphologies between older patients (≥60 years) and younger patients (<60 years) who have experienced cryptogenic ischemic strokes (CS).
  • Results show that older patients had a significantly higher prevalence of atrial septal aneurysm and more frequent septal malalignment, while other high-risk PFO features were similarly present in both age groups.
  • Overall, nearly 90% of older patients with PFO were classified as having a 'possible' link to their stroke, indicating that high-risk PFO morphologies are common across different age demographics.
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