Lgr6-expressing functional nail stem-like cells differentiated from human-induced pluripotent stem cells

The nail matrix containing stem cell populations produces nails and may contribute to fingertip regeneration. Nails are important tissues that maintain the functions of the hand and foot for handling objects and locomotion. Tumor chemotherapy impairs nail growth and, in many cases, loses them, although not permanently. In this report, we have achieved the successful differentiation of nail stem (NS)-like cells from human-induced pluripotent stem cells (iPSCs) via digit organoids by stepwise stimulation, tracing the molecular processes involved in limb development. Comprehensive mRNA sequencing analysis revealed that the digit organoid global gene expression profile fits human finger development. The NS-like cells expressed Lgr6 mRNA and protein and produced type-I keratin, KRT17, and type-II keratin, KRT81, which are abundant in nails. Furthermore, we succeeded in producing functional Lgr6-reporter human iPSCs. The reporter iPSC-derived Lgr6-positive cells also produced KRT17 and KRT81 proteins in the percutaneously transplanted region. To the best of our knowledge, this is the first report of NS-like cell differentiation from human iPSCs. Our differentiation method and reporter construct enable the discovery of drugs for nail repair and possibly fingertip-regenerative therapy.

Dynamics of somatostatin 4 receptor expression during chronic-stress loading and its potential as a chronic-stress marker

Chronic stress has been implicated in mental illnesses and depressive behaviors. Somatostatin 4 receptor (SSTR4) has been shown to mediate anxiolytic and depression-like effects. Here, we aimed to explore the potential of SSTR4 as a diagnostic marker for chronic stress in mice. The mice were divided into single stress, chronic restraint stress, and control groups, and Sstr4 mRNA expression in the pituitary, lungs, and thymus, its protein expression in the thymus, were analyzed. Compared to controls, Sstr4 mRNA expression decreased significantly in the pituitary gland of the chronic and single-stress groups (P = 0.0181 and 0.0022, respectively) and lungs of the single-stress group (P = 0.0124), whereas it significantly increased in the thymus of the chronic-stress group (P = 0.0313). Thymic SSTR4 expression did not decrease significantly in stress groups compared to that in the control group (P = 0.0963). These results suggest that SSTR4 expression fluctuates in response to stress. Furthermore, Sstr4 mRNA expression dynamics in each organ differed based on single or chronic restraint stress-loading periods. In conclusion, this study suggests that investigating SSTR4 expression in each organ could allow for its use as a stress marker to estimate the stress-loading period and aid in diagnosing chronic stress.

Specific Hydrogen Spillover Pathways Generated on Graphene Oxide Enabling the Formation of Non-Equilibrium Alloy Nanoparticles

The phenomenon of hydrogen spillover is investigated as a means of realizing a hydrogen-based society for over half a century. Herein, a graphene oxide having a precisely tuned architecture via calcination in air to introduce ether groups onto basal planes along with carbon defects is reported. This material provides specific pathways for the spillover of atomic hydrogen and has practical applications with regard to the synthesis of non-equilibrium solid-solution alloy nanoparticles. A combination of experimental work and simulations confirmed that the presence of ether groups associated with carbon defects facilitated hydrogen spillover within the basal planes of this graphene oxide. This enhanced hydrogen spillover ability, in turn, enables the simultaneous reduction of Ru3+ and Ni2+ ions to form RuNi alloy nanoparticles under hydrogen reduction conditions. Energy dispersive X-ray and X-ray absorption near edge structure simulations establish that this strategy forms unique alloy nanoparticles each comprising a Ru core with a RuNi solid-solution shell having a hexagonal close-packed structure. These non-equilibrium RuNi alloy nanoparticles exhibit greater catalytic activity than monometallic Ru nanoparticles during the hydrolysis of ammonia borane.

An Automated Culture System for Maintaining and Differentiating Human-Induced Pluripotent Stem Cells

Human induced pluripotent stem cells (hiPSCs) with infinite self-proliferating ability have been expected to have applications in numerous fields, including the elucidation of rare disease pathologies, the development of new medicines, and regenerative medicine aiming to restore damaged organs. Despite this, the social implementation of hiPSCs is still limited. This is partly because of the difficulty of reproducing differentiation in culture, even with advanced knowledge and sophisticated technical skills, due to the high sensitivity of iPSCs to minute environmental changes. The application of an automated culture system can solve this issue. Experiments with high reproducibility independent of a researcher's skill can be expected according to a shared procedure across various institutes. Although several automated culture systems that can maintain iPSC cultures and induce differentiation have been developed previously, these systems are heavy, large, and costly because they make use of humanized, multi-articulated robotic arms. To improve on the above issues, we developed a new system using a simple x-y-z axis slide rail system, allowing it to be more compact, lighter, and cheaper. Furthermore, the user can easily modify parameters in the new system to develop new handling tasks. Once a task is established, all the user needs to do is prepare the iPSC, supply the reagents and consumables needed for the desired task in advance, select the task number, and specify the time. We confirmed that the system could maintain iPSCs in an undifferentiated state through several passages without feeder cells and differentiate into various cell types, including cardiomyocytes, hepatocytes, neural progenitors, and keratinocytes. The system will enable highly reproducible experiments across institutions without the need for skilled researchers and will facilitate the social implementation of hiPSCs in a wider range of research fields by diminishing the obstacles for new entries.

Hollow carbon-based materials for electrocatalytic and thermocatalytic CO2 conversion

Electrocatalytic and thermocatalytic CO2 conversions provide promising routes to realize global carbon neutrality, and the development of corresponding advanced catalysts is important but challenging. Hollow-structured carbon (HSC) materials with striking features, including unique cavity structure, good permeability, large surface area, and readily functionalizable surface, are flexible platforms for designing high-performance catalysts. In this review, the topics range from the accurate design of HSC materials to specific electrocatalytic and thermocatalytic CO2 conversion applications, aiming to address the drawbacks of conventional catalysts, such as sluggish reaction kinetics, inadequate selectivity, and poor stability. Firstly, the synthetic methods of HSC, including the hard template route, soft template approach, and self-template strategy are summarized, with an evaluation of their characteristics and applicability. Subsequently, the functionalization strategies (nonmetal doping, metal single-atom anchoring, and metal nanoparticle modification) for HSC are comprehensively discussed. Lastly, the recent achievements of intriguing HSC-based materials in electrocatalytic and thermocatalytic CO2 conversion applications are presented, with a particular focus on revealing the relationship between catalyst structure and activity. We anticipate that the review can provide some ideas for designing highly active and durable catalytic systems for CO2 valorization and beyond.

Application of Live Mitochondria Staining in Cell-Sorting to Purify Hepatocytes Derived from Human Induced Pluripotent Stem Cells

Human embryonic stem (ES) and induced pluripotent stem (iPS) cells have potential applications in cell-based regenerative medicine for treating severely diseased organs due to their unlimited proliferation and pluripotent properties. However, differentiating human ES/iPS cells into 100% pure target cell types is challenging due to their high sensitivity to the environment. Tumorigenesis after transplantation is caused by contaminated, proliferating, and undifferentiated cells, making high-purification technology essential for the safe realization of regenerative medicine. To mitigate the risk of tumorigenesis, a high-purification technology has been developed for human iPS cell-derived hepatocytes. The method employs FACS (fluorescence-activated cell sorting) using a combination of high mitochondrial content and the cell-surface marker ALCAM (activated leukocyte cell adhesion molecule) without genetic modification. 97% ± 0.38% (n = 5) of the purified hepatocytes using this method exhibited albumin protein expression. This article aims to provide detailed procedures for this method, as applied to the most current two-dimensional differentiation method for human iPS cells into hepatocytes.

Efficient protocol for the differentiation of kidney podocytes from induced pluripotent stem cells, involving the inhibition of mTOR

The mechanistic/mammalian target of rapamycin (mTOR) is involved in a wide range of cellular processes. However, the role of mTOR in podocytes remains unclear. In this study, we aimed to clarify the role of mTOR in podocyte differentiation from human induced pluripotent stem cells (hiPSCs) and to establish an efficient differentiation protocol for human podocytes. We generated podocytes from hiPSCs by modifying protocol. The expression of the podocyte-specific slit membrane components nephrin and podocin was measured using PCR, western blotting, flow cytometry, and immunostaining; and the role of mTOR was evaluated using inhibitors of the mTOR pathway. Nephrin and podocin were found to be expressed in cells differentiated from hiPSCs, and their expression was increased by mTOR inhibitor treatment. S6, a downstream component of the mTOR pathway, was also found to be involved in podocyte differentiation. we evaluated its permeability to albumin, urea, and electrolytes. The induced podocytes were permeable to the small molecules, but only poorly permeable to albumin. We have shown that the mTOR pathway is involved in podocyte differentiation. Our monolayer podocyte differential protocol, using an mTOR inhibitor, provides a novel in vitro model for studies of kidney physiology and pathology.

Surface Chemical Engineering of a Metal 3D-Printed Flow Reactor Using a Metal-Organic Framework for Liquid-Phase Catalytic H2 Production from Hydrogen Storage Materials

The accurate positioning of metal-organic frameworks (MOFs) on the surface of other materials has opened up new possibilities for the development of multifunctional devices. We propose here a postfunctionalization approach for three-dimensional (3D)-printed metallic catalytic flow reactors based on MOFs. The Cu-based reactors were immersed into an acid solution containing an organic linker for the synthesis of MOFs, where Cu2+ ions dissolved in situ were assembled to form MOF crystals on the surface of the reactor. The resultant MOF layer served as a promising interface that enabled the deposition of catalytically active metal nanoparticles (NPs). It also acted as an efficient platform to provide carbonous layers via simple pyrolysis under inert gas conditions, which further enabled functionalization with organic modifiers and metal NPs. Cylindrical-shaped catalytic flow reactors with four different cell densities were used to investigate the effect of the structure of the reactors on the catalytic production of H2 from a liquid-phase hydrogen storage material. The activity increased with an increasing internal surface area but decreased in the reactor with the smallest cell size despite its high internal surface area. The results of fluid dynamics studies indicated that the effect of pressure loss becomes more pronounced as the pore size decreases.

The Induction of Parathyroid Cell Differentiation from Human Induced Pluripotent Stem Cells Promoted Via TGF-α/EGFR Signaling

The parathyroid gland plays an essential role in mineral and bone metabolism. Cultivation of physiological human parathyroid cells has yet to be established and the method by which parathyroid cells differentiate from pluripotent stem cells remains uncertain. Therefore, it has been hard to clarify the mechanisms underlying the onset of parathyroid disorders, such as hyperparathyroidism. In this study, we developed a new method of parathyroid cell differentiation from human induced pluripotent stem (iPS) cells. Parathyroid cell differentiation occurred in accordance with embryologic development. Differentiated cells, which expressed the parathyroid hormone, adopted unique cell aggregation similar to the parathyroid gland. In addition, these differentiated cells were identified as calcium-sensing receptor (CaSR)/epithelial cell adhesion molecule (EpCAM) double-positive cells. Interestingly, stimulation with transforming growth factor-α (TGF-α), which is considered a causative molecule of parathyroid hyperplasia, increased the CaSR/EpCAM double-positive cells, but this effect was suppressed by erlotinib, which is an epidermal growth factor receptor (EGFR) inhibitor. These results suggest that TGF-α/EGFR signaling promotes parathyroid cell differentiation from iPS cells in a similar manner to parathyroid hyperplasia.

Sub-nanometric High-Entropy Alloy Cluster: Hydrogen Spillover Driven Synthesis on CeO2 and Structural Reversibility

High-entropy alloy (HEA) nanoparticles (NPs) have attracted significant attention as promising catalysts owing to the various unique synergistic effects originating from the nanometer-scale, near-equimolar mixing of five or more components to produce single-phase solid solutions. However, the study of sub-nanometer HEA clusters having sizes of less than 1 nm remains incomplete despite the possibility of novel functions related to borderline molecular states with discrete quantum energy levels. The present work demonstrates the synthesis of CeO2 nanorods (CeO2-NRs) on which sub-nanometer CoNiCuZnPd HEA clusters were formed with the aid of a pronounced hydrogen spillover effect on readily reducible CeO2 (110) facets. The CoNiCuZnPd HEA sub-nanoclusters exhibited higher activity during the reduction of NO by H2 even at low temperatures compared with the corresponding monometallic catalysts. These clusters also showed a unique structural reversibility in response to repeated exposure to oxidative/reductive conditions, based on the sacrificial oxidation of the non-noble metals. Both experimental and theoretical analyses established that multielement mixing in quantum-sized regions endowed the HEA clusters with entirely novel catalytic properties.

Improved Low-Temperature Hydrogen Production from Aqueous Methanol Based on Synergism between Cationic Pt and Interfacial Basic LaOx

Aqueous phase reforming of methanol (APRM) is simple, inexpensive and provides a high hydrogen gravimetric density of 18.8 wt. %, and so is superior to traditional gas-phase reactions performed at relatively high temperatures. In the present work, the interface between Pt nanoparticles and a TiN support was modified using a highly dispersed amorphous LaOx phase. The resulting Pt/LaOx /TiO(N) exhibited enhanced activity and long-term stability during the APRM reaction under base-free conditions compared with Pt catalysts supported on unmodified TiN or crystalline La2 O3 . The interfacial amorphous LaOx phase promoted the deposition of small Pt nanoparticles having a narrow size distribution, and also generated electron-deficient Pt. An assessment of kinetic isotope data and theoretical investigations demonstrated that the cationic Pt nanoparticles facilitated the cleavage of O-H and C-H bonds in methanol while the amorphous LaOx enhanced the dissociation of water, thus enabling the water-gas shift reaction under mild conditions.

Immunohistochemical study of chicken fat clots: Investigation of the formation mechanism

In forensic practice, the presence of chicken fat clots (CFCs) in the heart and/or large blood vessels of cadavers has been empirically used to estimate the time from the onset of fatal events to death. However, little scientific evidence of its significance exists, and the mechanism of its formation has not been elucidated. CFCs contain large amounts of leukocytes; thus, we hypothesized that leukocytes might contribute to their formation. Since leukocytes, especially neutrophils, are considered to be involved in blood coagulation through the formation of neutrophil extracellular traps (NETs), we aimed to investigate whether NETs are related to the formation of CFCs through immunohistochemistry. Most cells in the CFCs were myeloperoxidase- and neutrophil elastase-positive, strongly suggesting that they were neutrophils. Since chromatin is released extracellularly during NET formation, immunostaining was performed against some types of histones in CFCs. A certain number of neutrophils in CFCs showed positive extra-nuclear and extracellular signals of histones. In addition, citrullination of histone H3, which is considered important for histone release, was immunohistochemically detected in some neutrophils. These results suggest that neutrophils may affect the formation of CFCs through histone release. Although it was not clear how and when citrullination and extracellular release of histones in CFCs occur in this study, our findings provide insights into the events occurring at the time of death in a human body.

Homogeneous Carbon Dot-Anchored Fe(III) Catalysts with Self-Regulated Proton Transfer for Recyclable Fenton Chemistry

Fenton chemistry has been widely studied in a broad range from geochemistry, chemical oxidation to tumor chemodynamic therapy. It was well established that Fe³⁺/H₂O₂ resulted in a sluggish initial rate or even inactivity. Herein, we report the homogeneous carbon dot-anchored Fe(III) catalysts (CD-COOFe^III) wherein CD-COOFe^III active center activates H₂O₂ to produce hydroxyl radicals (^•OH) reaching 105 times larger than that of the Fe³⁺/H₂O₂ system. The key is the ^•OH flux produced from the O-O bond reductive cleavage boosting by the high electron-transfer rate constants of CD defects and its self-regulated proton-transfer behavior probed by operando ATR-FTIR spectroscopy in D₂O and kinetic isotope effects, respectively. Organic molecules interact with CD-COOFe^III via hydrogen bonds, promoting the electron-transfer rate constants during the redox reaction of CD defects. The antibiotics removal efficiency in the CD-COOFe^III/H₂O₂ system is at least 51 times large than the Fe³⁺/H₂O₂ system under equivalent conditions. Our findings provide a new pathway for traditional Fenton chemistry.

Human Induced Pluripotent Stem Cell-Derived Keratinocyte-Like Cells for Research on Protease-Activated Receptor 2 in Nonhistaminergic Cascades of Atopic Dermatitis

Keratinocytes are the most abundant cells in the epidermis, and as part of the frontline immunologic defense system, keratinocytes function as a barrier to exogenous attacks. Protease-activated receptor 2 (PAR2) is expressed in human keratinocytes and activated in several inflammatory conditions, such as atopic dermatitis (AD). In this study, we demonstrated the differentiation of human induced pluripotent stem cell into keratinocytes by the improved, robust differentiation procedure and confirmed that human induced pluripotent stem cell-derived keratinocyte-like cells (iKera) express PAR2, which is activated by external addition of the ligand peptide and trypsin. The activation of PAR2 led to the release of calcium from intracellular calcium storage, followed by the release of the proinflammatory cytokine tumor necrosis factor α Moreover, PAR2 antagonist I-191 (CAS No. 1690172-25-8) inhibited calcium release in a dose-dependent manner. This is the first study to demonstrate that iKera expresses a functional PAR2 protein. Furthermore, our results indicate crosstalk between the PAR2- and IL-4-mediated inflammatory axes in iKera, suggesting that iKera can be used as a platform for a broad range of mechanism-targeted drug screening in AD. SIGNIFICANCE STATEMENT: This is the first study to provide evidence that human induced pluripotent stem cell-derived keratinocyte-like cells (iKera) express functional protease-activated receptor 2 (PAR2). Furthermore, this study demonstrated in iKera that the IL-4 inflammatory axis can crosstalk with the PAR2-mediated inflammatory axis in keratinocytes. To the best of our knowledge, this is the first report to indicate that iKera can be used for research and as a drug screening platform for atopic dermatitis.

Compact automated culture machine for human induced pluripotent stem cell maintenance and differentiation

The technologies used to generate human induced pluripotent stem cell (iPSC) from somatic cells potentially enable the wide application of iPSC-derived differentiated cells in industrial research fields as a replacement for animals. However, as highly trained individuals are required to obtain reproducible results, this approach has limited social implementation. In the research field of iPSC, it is believed that documentable information is not enough for reproducing the quality of the differentiated cells. Therefore, automated culture machines for cell processing should make the starting of iPSC-using researches easier. We developed a programmable all-in-one automated culture machine, with dense and compact constitution that fits within a normal biosafety cabinet (200 mm wide, 233 mm height, and 110 mm depth). This instrument was fabricated using novel x-y-z-axes-rail-system, such as an overhead traveling crane, in a factory, which served as the main handling machinery. This machine enabled stable and efficient expansion of human iPSC under the feeder-free condition, without karyotype alterations, and simultaneously differentiated the cells into various cell types, including cardiomyocytes, hepatocytes, neural progenitors, and keratinocytes. Overall, this machine would facilitate the social implementation of human pluripotent stem cells and contribute to the accumulation of sharable knowledge for the standardization of the entire handling processes of iPSC in pharmaceutical, food, and cosmetic research.

Reduction of noise induced by power supply lines using phase-locked loop

An experimental implementation for the reduction of power-line noise in delicate signal detection is presented. This implementation improves the signal-to-noise ratio without limiting the bandwidth of the measurement. A sinusoidal wave and its harmonics, both synchronized with the frequency of the power line, are used to cancel out the power supply noise induced in the measurement signal. The wave and the harmonics are generated via a phase-locked loop implementation. Their amplitude and phase are adjusted, and then they are added to the measurement signal using a series of operational amplifiers to compensate for the noise. Although we applied this method to the particular case of scanning tunneling microscopy measurements, considerably improving the image quality, our implementation can be applied to other measurement systems for which noise from the power lines can compromise the signal detection.

Electrochemical Reactors for Continuous Decentralized H2 O2 Production

The global utilization of H₂ O₂ is currently around 4 million tons per year and is expected to continue to increase in the future. H₂ O₂ is mainly produced by the anthraquinone process, which involves multiple steps in terms of alkylanthraquinone hydrogenation/oxidation in organic solvents and liquid-liquid extraction of H₂ O₂ . The energy-intensive and environmentally unfriendly anthraquinone process does not meet the requirements of sustainable and low-carbon development. The electrocatalytic two-electron (2 e^- ) oxygen reduction reaction (ORR) driven by renewable energy (e.g. solar and wind power) offers a more economical, low-carbon, and greener route to produce H₂ O₂ . However, continuous and decentralized H₂ O₂ electrosynthesis still poses many challenges. This Minireview first summarizes the development of devices for H₂ O₂ electrosynthesis, and then introduces each component, the assembly process, and some optimization strategies.

Development of defective molybdenum oxides for photocatalysis, thermal catalysis, and photothermal catalysis

The localized surface plasmon resonance (LSPR) of noble metals has been investigated for decades for applications in various catalysis reactions and optical research studies, but its development has been hampered by inefficient light absorption and high costs. In comparison, the creation of less expensive semiconductors (metal oxides) with strong plasmonic absorption is an appealing option, particularly defective molybdenum oxide (H_xMoO_3-y) has received considerable attention and investigation as a promising plasmonic material for a variety of catalytic reactions (photocatalysis, thermocatalysis, photothermal catalysis, etc.).The LSPR effect of H_xMoO_3-y can be tuned throughout a broad spectrum range from visible to near-infrared (NIR) by altering the doping amount by electrochemical control, chemical reduction, or photochemical control. Notably, defects (oxygen vacancies) in H_xMoO_3-y arise in conjunction with the LSPR effect, resulting in the formation of unique and useful active sites in a range of catalytic processes. In this review, we explore the formation mechanism of H_xMoO_3-y with plasmonic features and discuss its applications in photocatalysis, thermocatalysis, and photothermal catalysis.

P-199 Effect of the area of oocyte perivitelline space on the fertilization and embryo development following intracytoplasmic sperm injection

Study question

Does the area of oocyte perivitelline space have an effect on fertilization and embryo development following intracytoplasmic sperm injection?

Summary answer

The area of oocyte perivitelline space has not an effect on the fertilization but the embryo development following intracytoplasmic sperm injection.

What is known already

Oocyte perivitelline space has a lot of variation at intracytoplasmic sperm injection (ICSI). Some researchers reported that the characteristics of perivitelline space (large or small) affect embryo development, pregnancy, and implantation. However, these studies did not accurately calculate the area of perivitelline space. Therefore, little information is available on the effect of the area of oocyte perivitelline space on fertilization and embryo development following ICSI. The purpose of this study was to calculate and classify the area of oocyte perivitelline space and investigate the effect of the area of perivitelline space on fertilization and embryo development following ICSI.

Study design, size, duration

1. We retrospectively investigated 634 mature oocytes that were conducted ICSI between January 2021 and December 2021. The area of each oocyte perivitelline space was defined from between the area of circle calculated from the inner layer of zona pellucida and cytoplasm and divided into 3 groups (-9%, 10-19%, 20%-).

2. We retrospectively calculated the diameter of an inner layer of zona pellucida and cytoplasm and compared it with the 3 groups (-9%, 10-19%, 20%-).

Participants/materials, setting, methods

1. The fertilization, survival, good quality day-3 embryo, blastocyst, good quality blastocyst rates following ICSI were compared with the 3 groups (-9%, 10-19%, 20%-).

2. The average diameter of an inner layer of zona pellucida and cytoplasm of each oocyte for the 3 groups (-9%, 10-19%, 20%-) were compared.

The data were analyzed by Fisher’s exact test, residual analysis, one-way ANOVA test, with Bonferroni correction as appropriate to determine the statistical differences among groups.

Main results and the role of chance

1. The survival rates of perivitelline space -9%, 10-19%, 20%- groups were 100% (109/109), 96% (363/378), 94% (138/147), the fertilization rates were 89% (97/109), 88% (331/378), 86% (127/147), the good quality day-3 embryo rates were 56% (54/97), 70% (232/331), 70% (89/127) respectively. No significant difference was observed between these comparison items. The blastocyst rates of perivitelline space -9%, 10-19%, 20%- groups were 51% (47/92), 69% (222/321), 82% (93/114), the good quality blastocyst rates were 22% (20/92), 40% (129/321), 52% (59/114) respectively. The blastocyst and good quality blastocyst rates of perivitelline space -9% group showed significantly lower results. On the other hand, the blastocyst and good quality blastocyst rates of perivitelline space 20%- group showed significantly higher results.

2. The average diameter of an inner layer of zona pellucida of perivitelline space -9%, 10-19%, 20%- groups were 125 ± 4 µm, 129 ± 5 µm, 136 ± 6 µm, the average diameter of the cytoplasm of perivitelline space were 121 ± 4 µm, 119 ± 4 µm, 118 ± 4 µm respectively. Significant differences were observed in all pairs of groups of the average diameter of an inner layer of zona pellucida and cytoplasm.

Limitations, reasons for caution

The area of oocyte perivitelline space was calculated at only one plane.

Wider implications of the findings

Oocytes with narrow perivitelline space might have a wide region of adhesive between the cytoplasm surface and an inner layer of the zona pellucida which resulted in a smaller diameter of the zona pellucida and lower blastocyst rate by forming cytoplasmic fragments (Yumoto K et al. JARG. 2020 ;37(6):1349-1354.).

Trial registration number

Not Applicable

Effect of Long-Term Supplementation with Acetic Acid on the Skeletal Muscle of Aging Sprague Dawley Rats

Mitochondrial function in skeletal muscle, which plays an essential role in oxidative capacity and physical activity, declines with aging. Acetic acid activates AMP-activated protein kinase (AMPK), which plays a key role in the regulation of whole-body energy by phosphorylating key metabolic enzymes in both biosynthetic and oxidative pathways and stimulates gene expression associated with slow-twitch fibers and mitochondria in skeletal muscle cells. In this study, we investigate whether long-term supplementation with acetic acid improves age-related changes in the skeletal muscle of aging rats in association with the activation of AMPK. Male Sprague Dawley (SD) rats were administered acetic acid orally from 37 to 56 weeks of age. Long-term supplementation with acetic acid decreased the expression of atrophy-related genes, such as atrogin-1, muscle RING-finger protein-1 (MuRF1), and transforming growth factor beta (TGF-β), activated AMPK, and affected the proliferation of mitochondria and type I fiber-related molecules in muscles. The findings suggest that acetic acid exhibits an anti-aging function in the skeletal muscles of aging rats.

Overcoming Acidic H2O2/Fe(II/III) Redox-Induced Low H2O2 Utilization Efficiency by Carbon Quantum Dots Fenton-like Catalysis

Fenton reaction has important implications in biology- and environment-related remediation. Hydroxyl radicals (^•OH) and hydroxide (OH^-) were formed by a reaction between Fe(II) and hydrogen peroxide (H₂O₂). The acidic H₂O₂/Fe(II/III) redox-induced low H₂O₂ utilization efficiency is the bottleneck of Fenton reaction. Electron paramagnetic resonance, surface-enhanced Raman scattering, and density functional theory calculation indicate that the unpaired electrons in the defects of carbon quantum dots (CQDs) and the carboxylic groups at the edge have a synergistic effect on CQDs Fenton-like catalysis. This leads to a 33-fold higher H₂O₂ utilization efficiency in comparison with Fe(II)/H₂O₂ Fenton reaction, and the pseudo-first-order reaction rate constant (k_obs) increases 38-fold that of Fe(III)/H₂O₂ under equivalent conditions. The replacement of acidic H₂O₂/Fe(II/III) redox with CQD-mediated Fe(II/III) redox improves the sluggish Fe(II) generation. Highly effective production of ^•OH in CQDs-Fe(III)/H₂O₂ dramatically decreases the selectivity of toxic intermediate benzoquinone. The inorganic ions and dissolved organic matter (DOM) in real groundwater show negligible effects on the CQDs Fenton-like catalysis process. This work presents a process with a higher efficiency of utilization of H₂O₂in situ chemical oxidation (ISCO) to remove persistent organic pollutants.

Crystal Facet Engineering and Hydrogen Spillover-Assisted Synthesis of Defective Pt/TiO2-x Nanorods with Enhanced Visible Light-Driven Photocatalytic Activity

Hydrogen spillover can assist the introduction of defects such as Ti³⁺ and concomitant oxygen vacancies (V_O) in a TiO₂ crystal, thereby inducing a new level below the conduction band to improve the conductivity of photogenerated electrons and the visible light absorption property of TiO₂. Meanwhile, crystal facet engineering offers a promising approach to achieve improved activity by influencing the recombination step of the photogenerated electrons and holes. In this study, with the aim of achieving enhanced visible light-driven photocatalytic activity, rutile TiO₂ nanorods with different aspect ratios were synthesized by crystal facet engineering, and Pt-deposited TiO_2-x nanorods (Pt/TNR) were then obtained via reduction treatment assisted by hydrogen spillover. The reduction treatment at 200 °C induced the formation of surface Ti³⁺ exclusively, whereas surface Ti³⁺ and V_O were formed by performing the reduction at 600 °C. The Pt/TNR with a higher aspect ratio reduced at 200 °C exhibited the highest activity in photocatalytic H₂ production under visible light irradiation owing to the synergistic effect of the introduction of Ti³⁺ defects and the spatial charge carrier separation induced by crystal facet engineering.

Revealing hydrogen spillover pathways in reducible metal oxides

Hydrogen spillover, the migration of dissociated hydrogen atoms from noble metals to their support materials, is a ubiquitous phenomenon and is widely utilized in heterogeneous catalysis and hydrogen storage materials. However, in-depth understanding of the migration of spilled hydrogen over different types of supports is still lacking. Herein, hydrogen spillover in typical reducible metal oxides, such as TiO₂, CeO₂, and WO₃, was elucidated by combining systematic characterization methods involving various in situ techniques, kinetic analysis, and density functional theory calculations. TiO₂ and CeO₂ were proven to be promising platforms for the synthesis of non-equilibrium RuNi binary solid solution alloy nanoparticles displaying a synergistic promotional effect in the hydrolysis of ammonia borane. Such behaviour was driven by the simultaneous reduction of both metal cations under a H₂ atmosphere over TiO₂ and CeO₂, in which hydrogen spillover favorably occurred over their surfaces rather than within their bulk phases. Conversely, hydrogen atoms were found to preferentially migrate within the bulk prior to the surface over WO₃. Thus, the reductions of both metal cations occurred individually on WO₃, which resulted in the formation of segregated NPs with no activity enhancement.

The hydrogen spillover pathway in typical reducible metal oxides, such as TiO₂, CeO₂, and WO₃, was investigated by combining various in situ characterization techniques, kinetic analysis, and density functional theory calculations.

Lewis acid-triggered photocatalytic hydrogen peroxide production in an aluminum-based metal–organic framework

Al-based MIL-101-NH2, which was previously regarded as having silent photo-features, exhibits photocatalytic H2O2 production via O2 reduction accompanied by efficient suppression of undesired H2O2 decomposition.

Dual Active Centers Bridged by Oxygen Vacancies of Ru Single Atoms Hybrids Supported on Molybdenum Oxide for Photocatalytic Ammonia Synthesis

Photocatalytic synthesis of ammonia (NH 3 ) holds significant potential compared with the Haber-Bosch process. However, the reported photocatalysts suffered from low efficiency owing to localized electrons deficiency. Here, Ru-SA (single atoms)/H x MoO 3-y hybrids with abundant of Mo n+ (n < 6) species neighboring oxygen vacancies (O V ) are synthesized via a H-spillover process. Detailed characterizations demonstrate that Ru-SA/H x MoO 3 y hybrids can quantitatively produce NH 3 from N 2 and H 2 by the synergetic effect of dual active centers (Ru SA and Mo n+ ). That is, Ru SA boost the activation and migration of H 2 , and Mo n+ species act as the trapping sites of localized electrons and the adsorption and dissociation sites of N 2 , finally leading to NH 3 synthesis on Mo n+ -OH. The NH 3 generation rate is as high as 4.0 mmol h -1 g -1 , accompanied by an apparent quantum efficiency over 6.0% at 650 nm. Our finding may open up a new strategy for acquiring a better NH 3 synthesis approach under mild conditions.

Characteristic evaluation of a simple hand-made semiconductor dosimeter for mammography

Daily quality control of mammography equipment is important for providing optimal images and determining appropriate doses. To popularise dosimeters, the Measurement Division, the Japanese Society of Radiological Technology hold a seminar on making simple dosimeters. At this seminar, a hand-made dosimeter for mammography (HD-M) can be made at low cost. However, HD-Ms employ semiconductors, and their energy responses are subject to significant variations. This investigation involved the determination of precautions when using HD-Ms, examining their energy response characteristics and measurable energy ranges. HD-M has four types of selectors for response correction. When the selector and the tube voltage were equal, the HD-M readings matched that of the ionisation chamber within 5%. However, in case of target filter combinations and measuring tube voltages that the selector does not support, the HD-M readings differed by up to 53% from the ionisation chamber values. HD-M may use different measurement circuits and semiconductor elements depending on the time of the seminar. In this study, it was clarified that the correction factork, which is the average value of the ratio of the measured value of the ionisation chamber dosimeter to the measured value of HD-M, changes from 0.62 to 1.53 depending on irradiation conditions such as the combination of target filters and the tube voltage. It was demonstrated that HD-M functions sufficiently as a dosimeter for daily management by determining the correction factor using the method proposed in this study.

Defect Engineering of Pt/TiO2-x Photocatalysts via Reduction Treatment Assisted by Hydrogen Spillover

Defect engineering of metal oxides is a facile and promising strategy to improve their photocatalytic activity. In the present study, Pt/TiO_2-x was prepared by a reduction treatment assisted by hydrogen spillover to pure rutile, anatase, and brookite and was subsequently used for hydrogen production from an aqueous methanol solution. With increasing reduction temperature, the photocatalytic activity of the rutile Pt/TiO_2-x increased substantially, whereas the activity of anatase Pt/TiO_2-x decreased and that of brookite Pt/TiO_2-x was independent of the treatment temperature. Electron-spin resonance analysis revealed that rutile and brookite possess similar defect sites (Ti³⁺ and concomitant oxygen vacancy) after the reduction at 600 °C, whereas different resonance signals were observed for anatase after the reduction at 600 °C. During the reduction process, electrons donated from spillover hydrogen migrate between the conduction band and the inherent midgap states. This research demonstrates that the depth of the inherent midgap states, depending on the crystal phases, influences the generation of defects, which play a key role in the photocatalytic performance of Pt/TiO_2-x.

Development of age-estimation formula using postmortem oral findings: A pilot study

The goal of this pilot study was to develop an age-estimation formula and assess its effectiveness after evaluating individual intraoral findings. A total of 198 Japanese adults were included, and intraoral findings were collected from the corpses. To analyze the condition of each tooth, 20 items were established for intraoral findings, and seven tooth states were established. Logistic regression analysis was used to estimate the impact of age on each intraoral finding. Sequentially, linear regression was applied to verify the correlation between age and type of tooth, and multiple regression was used to correlate age-dependent factors. The intraoral findings with age dependency were tooth stump, edentulous jaw, attrition, no caries, dental prostheses, partial dentures, and complete dentures. Tooth stump, attrition, and dental prostheses showed positive multicollinearity. Missing tooth, extant tooth, normal teeth, and untreated lost teeth were age-correlated. Multiple regression analysis included age as the response variable and five factors as the explanatory variables in a new age-estimation formula, resulting in ± 10 years for 86.96% of cases (60-69 years old), 76.47% (70-79 years old), and 61.05% of all cases. The multiple correlation was 0.551, and the contribution rate of the multiple regression formula was 0.304. The accuracy of the proposed age-estimation formula was within ± 10 years for 61.05% of all subjects. However, the accuracy of age estimation in subjects aged 60-79 years was excellent (76.47-86.96%), which showed that this age-estimation formula would be effective for estimating the age of middle-aged to older subjects.

A quasi-stable molybdenum sub-oxide with abundant oxygen vacancies that promotes CO2 hydrogenation to methanol

Production of methanol from anthropogenic carbon dioxide (CO₂) is a promising chemical process that can alleviate both the environmental burden and the dependence on fossil fuels. In catalytic CO₂ hydrogenation to methanol, reduction of CO₂ to intermediate species is generally considered to be a crucial step. It is of great significance to design and develop advanced heterogeneous catalysts and to engineer the surface structures to promote CO₂-to-methanol conversion. We herein report an oxygen-defective molybdenum sub-oxide coupled with Pt nanoparticles (Pt/H_xMoO_3−y) which affords high methanol yield with a methanol formation rate of 1.53 mmol g_-cat⁻¹ h⁻¹ in liquid-phase CO₂ hydrogenation under relatively mild reaction conditions (total 4.0 MPa, 200 °C), outperforming other oxide-supported Pt catalysts in terms of both the yield and selectivity for methanol. Experiments and comprehensive analyses including in situ X-ray absorption fine structure (XAFS), in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and density functional theory (DFT) calculations reveal that both abundant surface oxygen vacancies (V_O) and the redox ability of Mo species in quasi-stable H_xMoO_3−y confer the catalyst with enhanced adsorption and activation capability to subsequently transform CO₂ to methanol. Moreover, the Pt NPs act as H₂ dissociation sites to regenerate oxygen vacancies and as hydrogenation sites for the CO intermediate to finally afford methanol. Based on the experimental and computational studies, an oxygen-vacancy-mediated “reverse Mars–van Krevelen (M–vK)” mechanism is proposed. This study affords a new strategy for the design and development of an efficient heterogeneous catalyst for CO₂ conversion.

Oxygen-defective molybdenum sub-oxide coupled with Pt nanoparticles affords high methanol yield in liquid-phase CO₂ hydrogenation via reverse Mars–van Krevelen mechanism.