Publications by authors named "Sekiguchi T"

High-quality thin lamellae are essential for state-of-the-art scanning transmission electron microscopy (S/TEM) analyses. While the preparation of S/TEM lamellae using focused ion beam (FIB-) scanning electron microscopy (SEM) has been established since the early 21st century, two critical factors have only recently been addressed: precise control over lamella thickness and a systematic understanding of FIB-induced damage. This study conducts an experimental investigation and simulation to explore how the intensities of backscattered and secondary electrons (BSEs and SEs, respectively) depend on lamellae thickness for semiconductor (Si), insulator (Al2O3), and metallic (stainless-steel) materials.

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Parathyroid hormone (PTH) is thought to induce remodeling-based bone formation by promoting osteoclastic activity, a process known as cellular coupling. Our research has shown that the frequency of PTH administration affects trabecular number and thickness. High-frequency PTH administration induced remodeling-based bone formation, while less frequent administration induced both remodeling-based and modeling-based bone formation.

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Although modern scanning electron microscope (SEM) possess several electron detectors, it is not clear what kind of information is contained in a SEM image taken by a certain detector. Especially the detectors installed in the objective lens are difficult to know their characters. Thus, we propose a simple method to assess the acceptance of electron detector using a stainless-steel sphere.

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Background: Social isolation and loneliness can co-occur; however, they are distinct concepts. There is discrepancy as some people feel lonely in social isolation, while others do not. This study sought to enhance our understanding of this discrepancy between social isolation and loneliness by investigating its related factors, with a specific focus on mental status and personality traits.

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Carbon dioxide (CO) photoreduction is an intriguing approach that converts CO into high-value substances with the assistance of a photocatalyst. Key to effective photoreduction is to promote the interaction of photo-induced holes and a sacrificial reagent (SCR), separating the holes from photoelectrons and enhancing the rate of the subsequent product generation. Methanol, ethanol, isopropanol, and water SCRs were tested for their ability to assist a copper-doped sodium dititanate nanosheets/graphene oxide heterostructure (CTGN) in CO photoreduction.

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Chloroplast ATP synthase (CFCF) synthesizes ATP by using a proton electrochemical gradient across the thylakoid membrane, termed ΔμH, as an energy source. This gradient is necessary not only for ATP synthesis but also for reductive activation of CFCF by thioredoxin, using reducing equivalents produced by the photosynthetic electron transport chain. ΔμH comprises two thermodynamic components: pH differences across the membrane (ΔpH) and the transmembrane electrical potential (ΔΨ).

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Article Synopsis
  • The study analyzed 5804 days of Super-Kamiokande data from 1996 to 2018 to detect variations in solar ^{8}B neutrino flux.
  • The researchers utilized a five-day interval measurement approach and employed maximum likelihood and Lomb-Scargle methods to find any periodic modulations.
  • They found a significant modulation related to Earth's elliptical orbit around the Sun, with measurements of eccentricity and perihelion shift aligning with astronomical data.
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  • The study investigated how parathyroid hormone (PTH) affects bone formation in different parts of the femur in mice, focusing on whether it promotes remodeling or modeling.
  • Mice were divided into groups that either received PTH (administered twice or four times a day) or a control treatment, and various markers were analyzed to see how bone cells responded in the trabecular regions near and far from the chondro-osseous junction (COJ).
  • Results indicated that PTH enhances remodeling near the COJ while promoting modeling in distant regions, and it also aids the transformation of osteoblasts into osteocytes during both processes.
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  • Graft-versus-host disease (GVHD) is a serious complication following allogeneic hematopoietic cell transplantation (HCT), impacting liver function, though the role of bile duct stem cells (BDSCs) in this process is not fully understood.
  • The study found that BDSCs initially expand and enhance liver organoid formation, but this ability declines as GVHD progresses, which correlates with a drop in biliary epithelial cells (BECs) and increased bilirubin levels.
  • Targeting TGF-β signaling with an inhibitor improved BDSC resilience and reduced biliary dysfunction, indicating that BDSCs could be key to developing treatments for hepatic GVHD.
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Objective: A type 2 endoleak (T2EL) is the most frequently occurring endoleak type after endovascular aneurysm repair (EVAR). Residual T2ELs may cause aneurysm rupture; however, the management of a T2EL remains controversial. This study evaluated sac branch preemptive embolization using N-butyl-2-cyanoacrylate, aiming to prevent T2ELs and sac shrinkage.

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Allogeneic T cell expansion is the primary determinant of graft-versus-host disease (GVHD), and current dogma dictates that this is driven by histocompatibility antigen disparities between donor and recipient. This paradigm represents a closed genetic system within which donor T cells interact with peptide-major histocompatibility complexes (MHCs), though clonal interrogation remains challenging due to the sparseness of the T cell repertoire. We developed a Bayesian model using donor and recipient T cell receptor (TCR) frequencies in murine stem cell transplant systems to define limited common expansion of T cell clones across genetically identical donor-recipient pairs.

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The chemical derivatization of target analytes can enhance the sensitivity and selectivity of separation-based methods for metabolite analysis using microfluidic devices. However, the development of chromatography-based microfluidic devices with integrated derivatization units is challenging. In this study, a novel derivatization unit with a pillar array (PA)-based mixing channel was developed for postcolumn derivatization during on-chip liquid chromatography (LC).

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Calcineurin inhibitors (CNIs) constitute the backbone of modern acute graft-versus-host disease (aGVHD) prophylaxis regimens but have limited efficacy in the prevention and treatment of chronic GVHD (cGVHD). We investigated the effect of CNIs on immune tolerance after stem cell transplantation with discovery-based single-cell gene expression and T cell receptor (TCR) assays of clonal immunity in tandem with traditional protein-based approaches and preclinical modeling. While cyclosporin and tacrolimus suppressed the clonal expansion of CD8+ T cells during GVHD, alloreactive CD4+ T cell clusters were preferentially expanded.

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In this study, we aimed to establish high-rate biological treatment of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) wastewater that minimizes the inhibitory effects of high concentration benzoate and acetate. To achieve this, we developed a novel bioreactor system and biostimulation strategy. An internal two-stage upflow anaerobic (ITUA) reactor was operated with (i) a packed bed containing green tuff medium underlying (ii) a compartment seeded with anaerobic granular sludge.

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Microdroplet-based fluidic systems have the advantages of small size, short diffusion time, and no cross-contamination; consequently, droplets often provide a fast and precise reaction environment as well as an analytical environment for individual molecules. In order to handle diverse reactions, we developed a method to create organic single-micron droplets (S-MDs) smaller than 5 μm in diameter dispersed in silicone oil without surfactant. The S-MD generation microflow device consists of a mother droplet (MoD) generator and a tapered separation channel featuring multiple side channels.

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Background: Asking questions is common in conversations, and while asking questions, we need to listen carefully to what others say and consider the perspective our questions adopt. However, difficulties persist in verifying the effect of asking questions on older adults' cognitive function due to the lack of a standardized system for conducting experiments at participants' homes.

Objective: This study examined the intervention effect of cognitive training moderated by robots on healthy older adults.

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Endothelial function and integrity are compromised after allogeneic bone marrow transplantation (BMT), but how this affects immune responses broadly remains unknown. Using a preclinical model of CMV reactivation after BMT, we found compromised antiviral humoral responses induced by IL-6 signaling. IL-6 signaling in T cells maintained Th1 cells, resulting in sustained IFN-γ secretion, which promoted endothelial cell (EC) injury, loss of the neonatal Fc receptor (FcRn) responsible for IgG recycling, and rapid IgG loss.

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The cholecystokinin (CCK)/gastrin family peptides are involved in regulation of feeding and digestion in vertebrates. In the ascidian Ciona intestinalis type A (Ciona robusta), cionin, a CCK/gastrin family peptide, has been identified. Cionin is expressed exclusively in the central nervous system (CNS).

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Neuroaxonal dystrophy (NAD) is a neurodegenerative disease characterized by spheroid (swollen axon) formation in the nervous system. In the present study, we focused on a newly established autosomal recessive mutant strain of F344-/ rats with hind limb gait abnormalities and ataxia from a young age. Histopathologically, a number of axonal spheroids were observed throughout the central nervous system, including the spinal cord (mainly in the dorsal cord), brain stem, and cerebellum in F344-/ rats.

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Severe hypertriglyceridemia is a pathological condition caused by genetic factors alone or in combination with environmental factors, sometimes leading to acute pancreatitis (AP). In this study, exome sequencing and biochemical analyses were performed in 4 patients with hypertriglyceridemia complicated by obesity or diabetes with a history of AP or decreased post-heparin LPL mass. In a patient with a history of AP, SNP rs199953320 resulting in LMF1 nonsense mutation and APOE rs7412 causing apolipoprotein E2 were both found in heterozygous form.

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Background: Recent climate changes have produced extreme climate events. This study focused on extreme snowfall and intended to discuss the vulnerability of temperate mammals against it through interspecies comparisons of spatial niches in northern Japan. We constructed niche models for seven non-hibernating species through wide-scaled snow tracking on skis, whose total survey length was 1144 km.

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Autologous stem cell transplantation (ASCT) is the standard of care consolidation therapy for eligible patients with myeloma but most patients eventually progress, an event associated with features of immune escape. Novel approaches to enhance antimyeloma immunity after ASCT represent a major unmet need. Here, we demonstrate that patient-mobilized stem cell grafts contain high numbers of effector CD8 T cells and immunosuppressive regulatory T cells (Tregs).

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In yeast, ras-like small G proteins, Gtr1p and Gtr2p, form heterodimers that affect cell division, detect amino acids, and regulate the activity of TORC1, a protein complex that integrates various signals, including those related to nutrient availability, growth factors, and stress signals. To explore novel roles of Gtr2p, yeast two-hybrid screening was performed using gtr2S23Np, an active form of Gtr2p, which identified Rps31p and Rpl12p as Gtr2p-interacting proteins. In the present study, we found that Gtr2p, but not Gtr1p, interacts with Rps31p, a 40S ribosomal subunit, and a component of the ubiquitin fusion protein Ubi3p, which is essential for the initiation and elongation of translation.

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