Publications by authors named "Takeshi Kasama"

One cyclic peptide immobilized on one gel-type bead has been employed for the discovery of both interacting peptides and/or medicinal medium-sized molecules. Although high-throughput characterization of recognized peptides has been a bottleneck, here, we describe direct liberation from beads by a one-pot reaction using 2-nitro-5-thiocyanatobenzoic acid followed by mass spectrometry to realize faster and routine sequencing of the peptide on the beads. This is useful for the investigation of protein-protein interactions as well as discovery of drug candidates.

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High-density lipoprotein (HDL) cholesterol is a well-known biomarker, which has been associated with reduction in the risk of cardiovascular diseases (CVD). However, some HDL anti-atherosclerotic functions may be impaired without altered HDL-cholesterol (HDL-C) level via its dysfunctional proteins or other physiological reactions in vivo. We previously showed that activated mast cell-derived chymase could modestly cleave apolipoprotein A-I (apoA-I) in HDL and further easily cleave lipid-free apoA-I.

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Medium sized molecules such as peptides and macrocycles have recently drawn much attention as potent sources of medicinal lead compounds, whereas the possibility of obtaining a practical drug from them remains limited. The present paper describes a concept of discovering novel medicinal targets or binding modes as well as lead compounds by the one-peptide-on-one-bead (OPOB) technology for comprehensive screening. The difficulty and problems in conventional drug discovery methods that generally deal with one predetermined target are considered.

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Construction of living artificial cells from genes and molecules can expand our understanding of life system and establish a new aspect of bioengineering. However, growth and division of cell membrane that are basis of cell proliferation are still difficult to reconstruct because a high-yielding phospholipid synthesis system has not been established. Here, we developed a cell-free phospholipid synthesis system that combines fatty acid synthesis and cell-free gene expression system synthesizing acyltransferases.

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This study sought to show the mechanism of how to ameliorate experimental autoimmune myocarditis (EAM) by administering dipeptidyl peptidase (DPP)-4 inhibitor linagliptin. The number of RAR-related orphan nuclear receptor gamma-positive Th17 cells infiltrated to the EAM myocardium was significantly attenuated by linagliptin treatment. Tandem mass spectrometry-based analysis demonstrated that DPP-4 binds to cathepsin G in EAM hearts, thereby protecting cathepsin G activity through inhibiting SerpinA3N activity.

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Liquid phase transmission electron microscopy (LPTEM) is rapidly developing as a powerful tool for probing processes in liquid environments with close to atomic resolution. Knowledge of the water thickness is needed for reliable interpretation and modelling of analytical studies in LPTEM, and is particularly essential when using thin liquid layers, required for achieving the highest spatial resolutions. The log-ratio method in electron energy-loss spectroscopy (EELS) is often applied in TEM to quantify the sample thickness, which is measured relative to the inelastic mean free path (λIMFP).

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Improving our experimental and theoretical knowledge of electric potentials at liquid-solid boundaries is essential to achieve a deeper understanding of the driving forces behind interfacial processes. Electron holography has proved successful in probing solid-solid interfaces but requires knowledge of the materials' mean inner potential (MIP, V_{0}), which is a fundamental bulk material property. Combining off-axis electron holography with liquid phase transmission electron microscopy (LPTEM), we provide the first quantitative MIP determination of liquid water V_{0}=+4.

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The sorption of selenite (Se(IV)) at trace (sub-ppm) to high concentrations on periclase (MgO) under high-pH conditions (pH > 10) was examined by macroscopic sorption experiments and nanoscale solid phase analyses via transmission electron microscopy and X-ray absorption spectroscopy. The maximum distribution coefficient (K) of Se(IV) on MgO was 100 L/g, the highest among any reported mineral sorbents at pH > 10. Since MgO is a metastable phase under ambient conditions, it transforms instantaneously to brucite (Mg(OH)) in solution.

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Although treatment of chronic myeloid leukemia (CML) has improved with the development of tyrosine kinase inhibitors (TKIs), patients develop fatal blast crisis (BC) whilst receiving TKI treatment. Alternative treatments for cases resistant to TKIs are required. A serine/threonine protein kinase, T‑lymphokine‑activated killer cell‑originated protein kinase (TOPK), is highly expressed in various malignant tumors.

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Quantum dots tuned to atomic resonances represent an emerging field of hybrid quantum systems where the advantages of quantum dots and natural atoms can be combined. Embedding quantum dots in nanowires boosts these systems with a set of powerful possibilities, such as precise positioning of the emitters, excellent photon extraction efficiency and direct electrical contacting of quantum dots. Notably, nanowire structures can be grown on silicon substrates, allowing for a straightforward integration with silicon-based photonic devices.

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Understanding the form of Se(IV) co-precipitated with ferrihydrite and its subsequent behavior during phase transformation is critical to predicting its long-term fate in a range of natural and engineered settings. In this work, Se(IV)-ferrihydrite co-precipitates formed at different pH were characterized with chemical extraction, transmission electron microscopy (TEM), and X-ray absorption spectroscopy (XAS) to determine how Se(IV) is associated with ferrihydrite. Results show that despite efficient removal, the mode and stability of Se(IV) retention in the co-precipitates varied with pH.

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Hydrogen silsesquioxane ([HSiO] )-based "spin-on-glass" has been deposited on a 316L substrate and cured in Ar/H gas atmosphere at 600 °C to form a continuous surface coating with submicrometer thickness. The coating functionality depends primarily on the adhesion to the substrate, which is largely affected by the chemical interaction at the interface between the coating and the substrate. We have investigated this interface by transmission electron microscopy and electron energy loss spectroscopy.

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Article Synopsis
  • Smith-Lemli-Opitz syndrome is a rare autosomal recessive disorder in Japan caused by mutations in the DHCR7 gene, leading to cholesterol synthesis issues.
  • The reported Japanese case involved a 46,XY disorder of sex development and additional physical features like Y-shaped 2-3 toe syndactyly.
  • Genetic analysis identified compound heterozygous mutations, including a novel mutation (H442R), and prompt diagnosis allowed for early cholesterol treatment.
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We report the effects of dissolved oxygen (DO) concentration and iron addition on gene expression of Magnetospirillum gryphiswaldense MSR-1 cells during fermentations, focusing on 0.25-24 h after iron addition. The DO was strictly controlled at 0.

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When using bifunctional core@shell catalysts, the stability of both the shell and core-shell interface is crucial for catalytic applications. In the present study, we elucidate the stability of a CuO/ZnO/Al2O3@ZSM-5 core@shell material, used for one-stage synthesis of dimethyl ether from synthesis gas. The catalyst stability was studied in a hierarchical manner by complementary environmental transmission electron microscopy (ETEM), scanning electron microscopy (SEM) and in situ hard X-ray ptychography with a specially designed in situ cell.

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The primitive streak in peri-implantation embryos forms the mesoderm and endoderm and controls cell differentiation. The metabolic cues regulating primitive streak formation remain largely unknown. Here we utilised a mouse embryonic stem (ES) cell differentiation system and a library of well-characterised drugs to identify these metabolic factors.

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Relatively larger scale peptide libraries immobilized on a gel-type solid support consisting of 24 natural and non-natural amino acids by the "split and combine method" have been constructed to find interacting molecules. The diversity was ca. 200 millions of hexapeptides with cysteinyl residues forming cyclotide.

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High-density lipoprotein (HDL) is involved in innate immunity toward various infectious diseases. Concerning bacteria, HDL is known to bind to lipopolysaccharide (LPS) and to neutralize its physiological activity. On the other hand, cholesterol is known to play an important role in mycobacterial entry into host cells and in survival in the intracellular environment.

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A photoresponsive inorganic microfiber with a plasmonic core-shell structure responds to visible light to achieve self-protection against oxidation in an open environment. The microfibers are synthesized via a newly developed reagent-free electrolytic method and have unique interfacial structures and high surface activity.

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We synthesized [2]rotaxanes with a pyrrole moiety from a [2]rotaxane with a 1,3-diynyl moiety. The conversion of the 1,3-diynyl moiety of the axle component to the pyrrole moiety was accomplished by a Cu-mediated cycloaddition of anilines. The cycloaddition reaction was accelerated when the [2]rotaxane was used as the substrate.

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We present new data about the chemical and structural characteristics of bauxite residue (BR) from Greek Al industry, using a combination of microscopic, analytical, and spectroscopic techniques. SEM-EDS indicated a homogeneous dominant "Al-Fe-Ca-Ti-Si-Na-Cr matrix", appearing at the microscale. The bulk chemical analyses showed considerable levels of Th (111 μg g(-1)), along with minor U (15 μg g(-1)), which are responsible for radioactivity (355 and 133 Bq kg(-1) for (232)Th and (238)U, respectively) with a total dose rate of 295 nGy h(-1).

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Rotacatenane is an interlocked compound composed of two mechanically interlocked macrocyclic components, i.e., a [2]catenane, and one axle component.

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Atomically dispersed noble-metal catalysts with highly dense active sites are promising materials with which to maximise metal efficiency and to enhance catalytic performance; however, their fabrication remains challenging because metal atoms are prone to sintering, especially at a high metal loading. A dynamic process of formation of isolated metal atom catalytic sites on the surface of the support, which was achieved starting from silver nanoparticles by using a thermal surface-mediated diffusion method, was observed directly by using in situ electron microscopy and in situ synchrotron X-ray diffraction. A combination of electron microscopy images with X-ray absorption spectra demonstrated that the silver atoms were anchored on five-fold oxygen-terminated cavities on the surface of the support to form highly dense isolated metal active sites, leading to excellent reactivity in catalytic oxidation at low temperature.

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Through evaporation of dense colloids of ferromagnetic ~13 nm ε-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400 nm and lengths of up to some hundred microns. Lorenz microscopy and electron holography reveal collective magnetic ordering in these structures. However, in contrast to continuous ferromagnetic thin films of comparable dimensions, domain walls appear preferentially as longitudinal, i.

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