Publications by authors named "Hitomi Y"

Article Synopsis
  • Laccase, a natural enzyme, faces challenges like limited temperature performance and high isolation costs, leading researchers to seek alternatives.
  • A new catalyst, copper-doped zeolitic imidazolate framework-67 (Cu-doped ZIF-67), was developed, using Cu for phenol oxidation and Co for oxygen reduction, mimicking laccase's functionality.
  • Cu-doped ZIF-67 shows enhanced catalytic performance compared to natural laccase, especially at higher temperatures, and remains stable through multiple reaction cycles, indicating its potential for industrial use.
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  • Polypharmacy, or the use of multiple medications, can increase the risk of adverse events in patients with chronic coronary syndrome (CCS), a group often prescribed many drugs.
  • A study involving 1,411 CCS patients found that those taking nine or more medications had a higher incidence of major adverse cardiovascular events (MACE) and overall mortality compared to those on fewer drugs.
  • The findings suggest that reducing the number of medications in CCS patients could potentially lower the risk of MACE and all-cause mortality, while still addressing other health conditions.
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  • Previous studies have found both shared and population-specific genetic factors contributing to primary biliary cholangitis (PBC), with more than 20 novel susceptibility loci identified in a recent meta-analysis across different populations.
  • A new genome-wide association study (GWAS) focused on the Japanese population identified the gene PTPN2 as a novel susceptibility gene for PBC, linking a specific variant (rs8098858) to the disease.
  • The risk allele (rs2292758) is shown to disrupt PTPN2 expression, leading to an impaired negative feedback mechanism in immune signaling, suggesting that targeting PTPN2 could be a promising approach for PBC treatment.
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In neurological and neuropsychiatric diseases, different brain regions are affected, and differences in gene expression patterns could potentially explain this mechanism. However, limited studies have precisely explored gene expression in different regions of the human brain. In this study, we performed long-read RNA sequencing on three different brain regions of the same individuals: the cerebellum, hypothalamus, and temporal cortex.

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CD58 plays roles in cell adhesion and co-stimulation with antigen presentation from major histocompatibility complex class II on antigen-presenting cells to T-cell antigen receptors on naïve T cells. CD58 reportedly contributes to the development of various human autoimmune diseases. Recently, genome-wide association studies (GWASs) identified CD58 as a susceptibility locus for autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS), and primary biliary cholangitis (PBC).

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The DNA target/ligand conjugates (HL, X = P and M, = 1-3) were synthesized where various lengths of -CONH(CHCHO)CHCHNHCO- linkers with a 9-phenanthrenyl (P) or methyl (M) terminal as DNA targets replace the methyl group of 2,6-di(amide-tether cyclen)-cresol ligand (HL). DNA binding, DNA cleavage, cellular uptake, and cytotoxicity of [Cu(μ-OH)(L)](ClO) () are examined and compared with those of [Cu(μ-OH)(L)](ClO) () to clarify roles of DNA targets. Upon reaction of with HO, μ-1,1-OH complexes are formed for DNA cleavage.

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Facial skin aging is the most visible manifestation of aging in the body. In this study, we aimed to rejuvenate aging skin via a one-time intradermal injection of autologous adipose-derived stem cells (ADSCs). Eight patients were enrolled for study.

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  • The Ryukyu Islands, located in southern Japan, have distinct histories and cultures that set them apart from mainland Japan, with genetic variations among their islander populations.
  • A study analyzed the whole genomes of 50 Ryukyu islanders, revealing significant genetic differences between Miyako and Okinawa islanders due to genetic drift rather than migration rates.
  • Findings suggest that the modern population structure stems from historical admixture with mainland Japanese rather than previous subpopulations from the Neolithic Ryukyu Jomon period.
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  • Primary biliary cholangitis (PBC) is an autoimmune disease linked to specific genetic factors, particularly related to the pyruvate dehydrogenase complex.
  • A study analyzed genetic data from 1,670 PBC patients and 2,328 healthy individuals, confirming 18 known Japanese PBC-associated alleles and discovering additional novel alleles that affect disease susceptibility.
  • Certain alleles were found to be associated with a higher risk of autoimmune hepatitis and hepatocellular carcinoma in PBC patients, enhancing understanding of genetic factors influencing disease progression and complications.
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Nanoparticles exhibiting enzymatic functions have garnered considerable attention due to their structural robustness and the profusion of active sites that can be introduced to a single nanosized particle. Here we report that nanosized mixed-metal zeolitic imidazolate frameworks (ZIFs) show a superoxide dismutase (SOD)-like catalytic activity. We chose a ZIF composed of copper and zinc ions and 2-methylimidazole, CuZn-ZIF-8, in which the Cu and Zn ions are bridged by an imidazolato ligand.

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Introduction: In the last ten years, Japan has experienced several large-scale earthquakes with devastating social and health impacts. Earthquakes directly and indirectly cause a variety of health problems. Further investigation is required to increase preparedness and preventive efforts.

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Numerous biomimetic molecular catalysts inspired by methane monooxygenases (MMOs) that utilize iron or copper-oxo species as key intermediates have been developed. However, the catalytic methane oxidation activities of biomimetic molecule-based catalysts are still much lower than those of MMOs. Herein, we report that the close stacking of a μ-nitrido-bridged iron phthalocyanine dimer onto a graphite surface is effective in achieving high catalytic methane oxidation activity.

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Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe to Fe and dehydration developed.

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Epoxides are essential precursors for epoxy resins and other chemical products. In this study, we investigated whether electrochemically oxidizing carbonate ions could produce percarbonate to promote an epoxidation reaction in the presence of appropriate metal catalysts, although Tanaka and co-workers had already completed a separate study in which the electrochemical oxidation of chloride ions was used to produce hypochlorite ions for electrochemical epoxidation. We found that epoxides could be obtained from styrene derivatives in the presence of metal complexes, including manganese(III) and oxidovanadium(IV) porphyrin complexes and manganese salen complexes, using a boron-doped diamond as the anode.

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Primary biliary cholangitis (PBC) is a chronic, progressive cholestatic liver disease in which the small intrahepatic bile ducts are destroyed by autoimmune reactions. Among autoimmune diseases, which are polygenic complex traits caused by the combined contribution of genetic and environmental factors, PBC exhibits the strongest involvement of genetic heritability in disease development. As at December 2022, genome-wide association studies (GWASs) and associated meta-analyses identified approximately 70 PBC susceptibility gene loci in various populations, including those of European and East Asian descent.

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The Hayabusa2 spacecraft collected samples from the surface of the carbonaceous near-Earth asteroid (162173) Ryugu and brought them to Earth. The samples were expected to contain organic molecules, which record processes that occurred in the early Solar System. We analyzed organic molecules extracted from the Ryugu surface samples.

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Samples of the carbonaceous asteroid (162173) Ryugu were collected and brought to Earth by the Hayabusa2 spacecraft. We investigated the macromolecular organic matter in Ryugu samples and found that it contains aromatic and aliphatic carbon, ketone, and carboxyl functional groups. The spectroscopic features of the organic matter are consistent with those in chemically primitive carbonaceous chondrite meteorites that experienced parent-body aqueous alteration (reactions with liquid water).

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Article Synopsis
  • The study investigates the impact of L-arginine bioavailability on long-term outcomes in patients with a history of coronary angiography.
  • Serum levels of L-arginine, L-citrulline, and L-ornithine were analyzed to explore their relationship with overall and cardiovascular-related deaths.
  • Results indicated that a lower L-arginine/L-ornithine ratio was linked to higher incidences of all-cause death, cardiovascular death, and major adverse cardiovascular events over a 10-year observation period.
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Background: Ligation of CD28 with ligands such as CD80 or CD86 provides a critical second signal alongside antigen presentation by class II major histocompatibility complex expressed on antigen-presenting cells through the T cell antigen receptor for naïve T cell activation. A number of studies suggested that CD28 plays an important role in the pathogenesis of various human diseases. Recent genome-wide association studies (GWASs) identified CD28 as a susceptibility locus for lymphocyte and eosinophil counts, multiple sclerosis, ulcerative colitis, celiac disease, rheumatoid arthritis, asthma, and primary biliary cholangitis.

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The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measured noble gas and nitrogen isotopes in Ryugu samples and found that they are dominated by presolar and primordial components, incorporated during Solar System formation.

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  • The Hayabusa2 spacecraft successfully returned to Earth from the asteroid 162173 Ryugu on December 6, 2020, and samples were recovered the next day.
  • The extracted gas from the sample container contained helium and neon and had unique extraterrestrial ratios, indicating some contamination from Earth’s atmosphere.
  • This mission marks the first successful return of gas species from a near-Earth asteroid, and discussions are held regarding the fragmentation of Ryugu grains in relation to the gas composition.
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  • Samples from the carbonaceous asteroid Ryugu, collected by the Hayabusa2 spacecraft, show evidence of carbon dioxide-bearing water inclusions in a pyrrhotite crystal, suggesting its parent asteroid formed in the outer Solar System.
  • The analyzed samples contain few high-temperature materials like chondrules, yet are abundant in low-temperature formation products like phyllosilicates and carbonates, indicating aqueous alteration in a low temperature, high pH environment.
  • Numerical simulations reveal that Ryugu's parent body likely formed about 2 million years after the Solar System began to develop, based on the mineralogical and physical properties of the samples.
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  • Nitric oxide (NO) plays a crucial role in maintaining blood vessel health, and its derivatives (NOx levels) were studied as potential indicators of NO production in patients after coronary catheterization.
  • In a follow-up of 143 patients over approximately 6.13 years, researchers found that higher levels of NOx were associated with increased risk of death from any cause and heart failure.
  • The study concluded that elevated serum NOx levels indicate a higher risk of mortality and heart failure, suggesting that they are important clinical markers rather than benign signs.
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  • A genome-wide association study was conducted with 318 chronic hepatitis B cases and 309 healthy controls from the Thai population to identify genetic factors influencing HBV persistence.
  • Significant associations were found with several alleles in the class II region, revealing specific protective and risk variants linked to HBV chronicity.
  • The study also highlighted novel candidate loci and identified rs1061307 as the primary functional variant, enhancing our understanding of chronic hepatitis B pathophysiology.
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