126 research outputs found

    Robust magnetic domain of Pt/Co/Au/Cr₂O₃/Pt stacked films with a perpendicular exchange bias

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    Magnetic domain pattern and magnetic domain wall motion are particularly important to understand the magnetization process. Here, we investigated the magnetization process of perpendicularly exchange-biased Pt/Co/Au/Cr₂O₃/Pt stacked films based on observations of the magnetic domain. In particular, in contrast to previous studies which use fully exchange-biased state, we used the bi-exchange-biased state. We found that the magnetic domain pattern at the remanent state was robust against magnetic-field cycling, which is relevant to the absence of the training effect. The magnetization process was followed by domain wall propagation in the increasing branch of the magnetization curve. In the decreasing branch, both nucleation of the reversed domain and domain wall propagation were involved. The former was accompanied by latency, suggesting that thermal activation played a significant role in the nucleation of the reversed domain.Yu Shiratsuchi, Saori Yoshida, Hiroaki Yoshida, Yoshinori Kotani, Kentaro Toyoki, Ryoichi Nakatani, Chiharu Mitsumata, and Tetsuya Nakamura, Journal of Applied Physics 127, 153902 (2020); https://doi.org/10.1063/5.0002240

    Sonographic size of newborn testis

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    Purpose : It is essential to determine normative data of testicular size and penile length in newborn infants in order to assess the development during the fetal period. In this study, we evaluated testicular volumes using ultrasonography and also measured penile lengths in Japanese newborn infants. We also examined the associations of the development of these organs with factors including placental weight and anthropometric data. Methods : One hundred and fifteen full-term male newborn infants were recruited for this study. Testicular size was measured by ultrasonography. Results : Mean testicular volumes were 187.4 mm3 in the right testis and 185.4 mm3 in the left testis, and there was no significant difference between the right and left testicular volumes. Right and left testicular volumes showed positive and significant correlations with body lengths and weights. Testicular volumes in the right and left sides were not significantly associated with penile lengths. In 4 groups according to gestational weeks, testicular volume increased significantly with advance of gestational weeks in the left testis. Conclusion : We determined testicular volumes using ultrasonography in Japanese newborn infants. We believe that the results for newborn infants provide important information for assessment of the development of fetal testicular volume

    Enhancement of perpendicular exchange bias by introducing twin boundary in Pt/Co/α-Cr₂O₃/α-V₂O₃ epitaxial film

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    Perpendicular exchange anisotropy at the Co/α-Cr₂O₃ interface was investigated using the two types of films: the film with the single crystalline α-Cr₂O₃ and that with the twinned a-Cr₂O₃. Exchange anisotropy energy density JK of the film with the single crystalline α-Cr₂O₃ was ~0.09 erg/cm² whereas JK of the film with the twinned α-Cr₂O₃ was ~0.43 erg/cm², more than 4-times enhancement. We discussed the mechanism of the enhancement of JK based on the exchange coupling at the twin boundary and that the spin frustration at the twin boundary can be the origin of the enhancement of JK.Y.Shiratsuchi, S.Yoshida, S.Onoue, et al. Enhancement of perpendicular exchange bias by introducing twin boundary in Pt/Co/a-Cr₂O₃/a-V₂O₃ epitaxial film. Materials Transactions 60, 2028 (2019); https://doi.org/10.2320/matertrans.MT-M2019102

    Intrauterine Pressures Adjusted by Reichert's Membrane Are Crucial for Early Mouse Morphogenesis

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    Mammalian embryogenesis proceeds in utero with the support of nutrients and gases from maternal tissues. However, the contribution of the mechanical environment provided by the uterus to embryogenesis remains unaddressed. Notably, how intrauterine pressures are produced, accurately adjusted, and exerted on embryos are completely unknown. Here, we find that Reichert’s membrane, a specialized basement membrane that wraps around the implanted mouse embryo, plays a crucial role as a shock absorber to protect embryos from intrauterine pressures. Notably, intrauterine pressures are produced by uterine smooth muscle contractions, showing the highest and most frequent periodic peaks just after implantation. Mechanistically, such pressures are adjusted within the sealed space between the embryo and uterus created by Reichert’s membrane and are involved in egg-cylinder morphogenesis as an important biomechanical environment in utero. Thus, we propose the buffer space sealed by Reichert’s membrane cushions and disperses intrauterine pressures exerted on embryos for egg-cylinder morphogenesis

    New insights into the heat of adsorption of water, acetonitrile, and n-hexane in porous carbon with oxygen functional groups

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    Isosteric heat of adsorption is exquisitely sensitive to structural changes in carbon surfaces based on the energetic behavior of the interactions between adsorbates and carbon materials. We discuss the relationships between porous structures, oxygen functional groups, and heat of adsorption based on the behavior of the heat of adsorption of polar and non-polar fluids on porous carbon materials with oxygen functional groups. The porosity and functional groups of porous carbon materials were estimated from N2 adsorption isotherms at 77 K and temperature-programmed desorption. High-resolution adsorption isotherms of water, acetonitrile (polar fluid), and n-hexane (non-polar fluid) were measured on porous carbon materials with different pore size distributions and amounts of oxygen functional groups at various temperatures. The heats of adsorption were determined by applying the Clausius-Clapeyron equation to the adsorption isotherms. The heat of adsorption curves directly reflect the effects of interactions of fluid-oxygen functional groups,fluid-basal planes of pore walls, and fluid-fluid interfaces. In particular, the heat of adsorption curve of water is very sensitive to surface oxygen functional groups. This finding indicates the possibility of estimating the relative amounts of oxygen functional groups on porous carbon materials based on the amounts of water adsorbed at specific relative pressures

    Coordinately Co-opted Multiple Transposable Elements Constitute an Enhancer for wnt5a Expression in the Mammalian Secondary Palate

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    Acquisition of cis-regulatory elements is a major driving force of evolution, and there are several examples of developmental enhancers derived from transposable elements (TEs). However, it remains unclear whether one enhancer element could have been produced via cooperation among multiple, yet distinct, TEs during evolution. Here we show that an evolutionarily conserved genomic region named AS3_9 comprises three TEs (AmnSINE1, X6b_DNA and MER117), inserted side-by-side, and functions as a distal enhancer for wnt5a expression during morphogenesis of the mammalian secondary palate. Functional analysis of each TE revealed step-by-step retroposition/transposition and co-option together with acquisition of a binding site for Msx1 for its full enhancer function during mammalian evolution. The present study provides a new perspective suggesting that a huge variety of TEs, in combination, could have accelerated the diversity of cis-regulatory elements involved in morphological evolution

    Extracellular Vesicles Enriched with Moonlighting Metalloproteinase Are Highly Transmissive, Pro-Tumorigenic, and Trans-Activates Cellular Communication Network Factor (CCN2/CTGF) : CRISPR against Cancer

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    Matrix metalloproteinase 3 (MMP3) plays multiple roles in extracellular proteolysis as well as intracellular transcription, prompting a new definition of moonlighting metalloproteinase (MMP), according to a definition of protein moonlighting (or gene sharing), a phenomenon by which a protein can perform more than one function. Indeed, connective tissue growth factor (CTGF, aka cellular communication network factor 2 (CCN2)) is transcriptionally induced as well as cleaved by MMP3. Moreover, several members of the MMP family have been found within tumor-derived extracellular vesicles (EVs). We here investigated the roles of MMP3-rich EVs in tumor progression, molecular transmission, and gene regulation. EVs derived from a rapidly metastatic cancer cell line (LuM1) were enriched in MMP3 and a C-terminal half fragment of CCN2/CTGF. MMP3-rich, LuM1-derived EVs were disseminated to multiple organs through body fluid and were pro-tumorigenic in an allograft mouse model, which prompted us to define LuM1-EVs as oncosomes in the present study. Oncosome-derived MMP3 was transferred into recipient cell nuclei and thereby trans-activated the CCN2/CTGF promoter, and induced CCN2/CTGF production in vitro. TRENDIC and other cis-elements in the CCN2/CTGF promoter were essential for the oncosomal responsivity. The CRISPR/Cas9-mediated knockout of MMP3 showed significant anti-tumor effects such as the inhibition of migration and invasion of tumor cells, and a reduction in CCN2/CTGF promoter activity and fragmentations in vitro. A high expression level of MMP3 or CCN2/CTGF mRNA was prognostic and unfavorable in particular types of cancers including head and neck, lung, pancreatic, cervical, stomach, and urothelial cancers. These data newly demonstrate that oncogenic EVs-derived MMP is a transmissive trans-activator for the cellular communication network gene and promotes tumorigenesis at distant sites
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