Publications by authors named "Ryo Yoshida"

We elucidated the stimuli-responsive phase transition in a synthetic model of marginally stable proteins composed of poly(-isopropylacrylamide) with incorporated redox-responsive sites. Redox-state changes in a single redox-responsive site were efficiently converted to hydration and dehydration of multiple monomer units within the polymer chain synchronized with electron transfer.

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Active matter, characterized by its ability to exhibit autonomous and dynamic behavior, has emerged as a promising platform for mimicking complex biological processes. In biological systems, electrochemical signaling plays a vital role in regulating their dynamic processes, such as muscle contraction. Drawing inspiration from these mechanisms, we demonstrate that electrochemical signaling can effectively modulate the autonomous motion of self-oscillating gels (SOGs), a model active matter system driven by the Belousov - Zhabotinsky reaction.

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In living systems, dynamic biomacromolecular assemblies are driven and regulated by energy dissipative chemical reaction networks, enabling various autonomous functions. Inspired by this biological principle, we report a chemically-fueled phase transition of a poly(-isopropylacrylamide) (PNIPAAm)-based polymer bearing viologen units (P(NIPAAm-V)), wherein redox changes drive coil-to-globule phase transitions. Upon the addition of a reducing agent, viologen moieties in P(NIPAAm-V) are converted into their reduced state, resulting in enhanced hydrophobicity and polymer aggregation.

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Objectives: Low-level laser therapy (LLLT) using an erbium-doped yttrium aluminum garnet (Er:YAG) laser provides a non-invasive approach applicable to various dental treatments. Here, we investigated the effects of Er:YAG laser irradiation on human dental pulp stem cells (hDPSCs) in an in vitro experiment.

Methods: The hDPSCs were categorized into four groups: laser-irradiated with activators (VLT: activated vitamin D, bone morphogenetic protein receptor inhibitor, and transforming growth factor-beta (TGF-β)) (LLLT(+)VLT), laser-irradiated without activators (LLLT(+)-only), non-irradiated with activators (LLLT(-)VLT), and non-irradiated without activators (control).

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This study presents a novel approach to control "linked property changes" in hydrogels. Specifically, we controlled the swelling behaviour without altering the bulk elastic modulus by grafting polymers selectively into the surface region of the gels, while varying the graft amount.

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The cholesterol balance and bile acid metabolism in a mouse model of hepatic lipid accumulation induced by a diet supplemented with cholesterol and cholic acid (CA) were quantitatively evaluated. The mice were fed diets supplemented with different levels of cholesterol (0, 3, or 6 g/kg of diet) and CA (0.5 g/kg of diet) for 6 weeks.

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Quasicrystals are solid-state materials that typically exhibit unique symmetries, such as icosahedral or decagonal diffraction symmetry. They were first discovered in 1984. Over the past four decades of quasicrystal research, around 100 stable quasicrystals have been discovered.

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Aquatic environments host various living organisms with active molecular systems, such as the enzymes in the thylakoid membrane that realise photosynthesis. Various challenges in achieving artificial photosynthesis, such as water splitting, have been studied using both inorganic and organic molecules. However, several problems persist, including diffusion-limited reactions and multiple redox reactions in the liquid phase.

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Developing artificial autonomous materials is crucial for a deeper understanding of the emergence of life-like behavior. In nature, cells achieve autonomy through chemical processing systems incorporated into soft material-based frameworks. Inspired by natural cells, we herein describe a straightforward methodology for constructing artificial autonomous materials consisting of a polymer-based chemical processing system and a hydrogel-based soft framework.

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A hyperthermophilic archaeon, Aeropyrum pernix, synthesizes C,C-archaeal membrane lipids, or extended archaeal membrane lipids, which contain two C isoprenoid chains that are linked to glycerol-1-phosphate via ether bonds and are longer than the usual C,C-archaeal membrane lipids. The C,C-archaeal membrane lipids are believed to allow the archaeon to survive under harsh conditions, because they are able to form lipid membranes that are impermeable at temperatures approaching the boiling point. The effect that C,C-archaeal membrane lipids exert on living cells, however, remains unproven along with an explanation for why the hyperthermophilic archaeon synthesizes these specific lipids instead of the more common C,C-archaeal lipids or double-headed tetraether lipids.

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Background: Cervical spinal cord injury (CSI) often leads to impaired respiratory function, affecting the overall well-being of patients. This study aimed to investigate the influence of rib cage motion on inspiratory capacity in CSI patients.

Methods: We conducted a study with 11 CSI patients, utilising respiratory inductance plethysmography (RIP).

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Article Synopsis
  • Emergent properties in biological systems are important for understanding synchronization among oscillators, which can be studied using artificial models like Belousov-Zhabotinsky (BZ) oscillators.
  • By creating a self-oscillating gel system infused with acrylic acid, researchers can experimentally observe how clusters form and behave together during the BZ reaction.
  • This study reveals that when gel units in a heterogeneous cluster synchronize their periods and amplitudes, it showcases emergent properties, which could help advance our knowledge of synchronization in biological oscillators like heart cells (cardiomyocytes).
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Self-oscillating gel systems exhibiting an expanded operating temperature and accompanying functional adaptability are showcased. The developed system contains nonthermoresponsive main-monomers, such as N,N-dimethylacrylamide (DMAAm) or 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or acrylamide (AAm) or 3-(methacryloylamino)propyl trimethylammonium chloride (MAPTAC). The gels volumetrically self-oscillate within the range of the conventional (20.

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In computational neurolinguistics, it has been demonstrated that hierarchical models such as recurrent neural network grammars (RNNGs), which jointly generate word sequences and their syntactic structures via the syntactic composition, better explained human brain activity than sequential models such as long short-term memory networks (LSTMs). However, the vanilla RNNG has employed the top-down parsing strategy, which has been pointed out in the psycholinguistics literature as suboptimal especially for head-final/left-branching languages, and alternatively the left-corner parsing strategy has been proposed as the psychologically plausible parsing strategy. In this article, building on this line of inquiry, we investigate not only whether hierarchical models like RNNGs better explain human brain activity than sequential models like LSTMs, but also which parsing strategy is more neurobiologically plausible, by developing a novel fMRI corpus where participants read newspaper articles in a head-final/left-branching language, namely Japanese, through the naturalistic fMRI experiment.

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Smart polymer materials that are nonliving yet exhibit complex "life-like" or biomimetic behaviors have been the focus of intensive research over the past decades, in the quest to broaden our understanding of how living systems function under nonequilibrium conditions. Identification of how chemical and mechanical coupling can generate resonance and entrainment with other cells or external environment is an important research question. We prepared Belousov-Zhabotinsky (BZ) self-oscillating hydrogels which convert chemical energy to mechanical oscillation.

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The recent advancements in large-scale activity imaging of neuronal ensembles offer valuable opportunities to comprehend the process involved in generating brain activity patterns and understanding how information is transmitted between neurons or neuronal ensembles. However, existing methodologies for extracting the underlying properties that generate overall dynamics are still limited. In this study, we applied previously unexplored methodologies to analyze time-lapse 3D imaging (4D imaging) data of head neurons of the nematode Caenorhabditis elegans.

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Here we introduce sub-millimeter self-oscillating gels that undergo the Belousov-Zhabotinsky (BZ) reaction and can anisotropically oscillate like cardiomyocytes. The anisotropically self-oscillating gels in this study were realized by spatially patterning an acrylic acid-based interpenetrating network (AA-IPN). We found that the patterned AA-IPN regions, locally introduced at both ends of the gels through UV photolithography, can constrain the horizontal gel shape deformation during the BZ reaction.

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Since the discovery of the quasicrystal, approximately 100 stable quasicrystals are identified. To date, the existence of quasicrystals is verified using transmission electron microscopy; however, this technique requires significantly more elaboration than rapid and automatic powder X-ray diffraction. Therefore, to facilitate the search for novel quasicrystals, developing a rapid technique for phase-identification from powder diffraction patterns is desirable.

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Recent advances in machine learning have led to the rapid adoption of various computational methods for de novo molecular design in polymer research, including high-throughput virtual screening and inverse molecular design. In such workflows, molecular generators play an essential role in creation or sequential modification of candidate polymer structures. Machine learning-assisted molecular design has made great technical progress over the past few years.

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Here, we designed a surface-grafted hydrogel (SG gel) that exhibits thermoresponsive changes in surface properties. Quantitative measurements using a self-made device showed that the adhesive strength between the SG gel surface and a Bakelite plate due to hydrophobic interaction changed significantly with temperature.

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In this study, we established a fabrication method and analyzed the volumetric self-oscillatory behaviors of submillimeter-sized spherical self-oscillating gels. We validated that the manufactured submillimeter-sized spherical self-oscillating gels exhibited isotropic volumetric oscillations during the Belousov-Zhabotinsky (BZ) reaction. In addition, we experimentally elucidated that the volumetric self-oscillatory behaviors (, period and amplitude) and the oscillatory profiles depended on the following parameters: (1) the molar composition of -(3-aminopropyl)methacrylamide hydrochloride (NAPMAm) in the gels and (2) the concentration of Ru(bpy)-NHS solution containing an active ester group on conjugation.

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HNF4α regulates various genes to maintain liver function. There have been reports linking HNF4α expression to the development of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis. In this study, liver-specific Hnf4a-deficient mice (Hnf4aΔHep mice) developed hepatosteatosis and liver fibrosis, and they were found to have difficulty utilizing glucose.

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A primary interest in cell membrane and shape fluctuations is establishing experimental models reflecting only nonthermal active contributions. Here we report a millimeter-scaled capsule self-oscillating gel model mirroring the active contribution effect on cell fluctuations. In the capsule self-oscillating gels, the propagating chemical signals during a Belousov-Zhabotinsky (BZ) reaction induce simultaneous local deformations in the various regions, showing cell-like shape fluctuations.

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Heartbeats with different ventricular contractions vary with heart regions, which can be described as anisotropy. Herein, we report self-oscillating gels which exhibit region-dependent anisotropic volumetric oscillation behavior similar to that of the heart. We installed a (Ru(bpy)) gradient transducer on self-oscillating gels by employing slow and unidirectional diffusion in the gels and dipping part of the gel into a Ru(bpy)-NHS solution.

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Synopsis of recent research by authors named "Ryo Yoshida"

  • - Ryo Yoshida's recent research primarily focuses on the development of bioinspired materials, specifically hydrogels that mimic natural processes such as photosynthesis and autonomous motion, which could enhance our understanding of life-like behaviors in artificial systems.
  • - Key findings from his studies include the construction of self-oscillating gels that respond to chemical stimuli and exhibit emergent properties similar to biological systems, as well as the exploration of high-temperature resistant archaeal membrane lipids that may have implications for cell survival under extreme conditions.
  • - Additionally, Yoshida's interdisciplinary work intersects fields like computational neurolinguistics and bioengineering, demonstrating how hierarchical models can better explain neural dynamics, thereby bridging gaps between synthetic material design and biological insights.