227 research outputs found

    Apatite Formation Abilities and Mechanical Properties of Hydroxyethylmethacrylate-based Organic-inorganic Hybrids Incorporated with Sulfonic Groups and Calcium Ions

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    Apatite formation in the living body is an essential requirement for artificial materials to exhibit bone-bonding bioactivity. It has been recently revealed that sulfonic groups trigger apatite nucleation in a body environment. Organic–inorganic hybrids consisting of organic polymers and the sulfonic groups are therefore expected to be useful for preparation of novel bone-repairing materials exhibiting flexibility as well as bioactivity. In the present study, organic–inorganic hybrids were prepared from hydroxyethylmethacrylate (HEMA) in the presence of vinylsulfonic acid sodium salt (VSAS) and calcium chloride (CaCl2). The bioactivities of the hybrids were assessed in vitro by examining the apatite formation in simulated body fluid (SBF, Kokubo solution). The hybrids deposited on the apatite after soaking in SBF within 7 days. Tensile strength measurements showed a tendency to increase with increases in VSAS and CaCl2 content. It was assumed that this phenomenon was attributed to the formation of cross-linking in the hybrids

    Apatite Formation Abilities and Mechanical Properties of Hydroxyethylmethacrylate-based Organic-inorganic Hybrids Incorporated with Sulfonic Groups and Calcium Ions

    Get PDF
    Apatite formation in the living body is an essential requirement for artificial materials to exhibit bone-bonding bioactivity. It has been recently revealed that sulfonic groups trigger apatite nucleation in a body environment. Organic–inorganic hybrids consisting of organic polymers and the sulfonic groups are therefore expected to be useful for preparation of novel bone-repairing materials exhibiting flexibility as well as bioactivity. In the present study, organic–inorganic hybrids were prepared from hydroxyethylmethacrylate (HEMA) in the presence of vinylsulfonic acid sodium salt (VSAS) and calcium chloride (CaCl2). The bioactivities of the hybrids were assessed in vitro by examining the apatite formation in simulated body fluid (SBF, Kokubo solution). The hybrids deposited on the apatite after soaking in SBF within 7 days. Tensile strength measurements showed a tendency to increase with increases in VSAS and CaCl2 content. It was assumed that this phenomenon was attributed to the formation of cross-linking in the hybrids

    Structural Study of Binary Phosphate Glasses by X-ray and Neutron Diffraction

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    X-ray and neutron diffraction study on the structure of five binary metaphosphate glasses has been made by applying the pair function method coupled with the interference function refining technique. The distances and coordination numbers for the pairs of P-O, O-O and M-O (M=Li, Na, Zn, Mg, and Ca) were determined and a fundamental local ordering unit structure in these binary phosphate glasses has been confirmed to be a PO_4 tetrahedron and the particular features have also been recognized with respect to the numbers of oxygens around magnesium and zinc cations

    Functional relevance of the precuneus in verbal politeness.

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    Non-competitive and non-threatening aspects of social hierarchy, such as politeness, are universal among human cultures, and might have evolved from ritualized submission in primates; however, these behaviors have rarely been studied. Honorific language is a type of polite linguistic communication that plays an important role in human social interactions ranging from everyday conversation to international diplomacy. Here, functional magnetic resonance imaging (fMRI) revealed selective precuneus activation during a verbal politeness judgment task, but not other linguistic-judgment or social-status recognition tasks. The magnitude of the activation was correlated with the task performance. Functional suppression of the activation using cathodal transcranial direct-current stimulation reduced performance in the politeness task. These results suggest that the precuneus is an essential hub of the verbal politeness judgment

    Delayed Surgery for Congenital Diaphragmatic Hernia

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    Infants with congenital diaphragmatic hernia (CDH) operated on at 12 hours of age have poor prognosis. Development of severe hypoxemia due to hypoplastic lung and pulmonary vascular constriction is the major prognostic factor. Infants who show reasonable gas exchange at first but develop severe hypoxemia a few hours following surgery (honeymoon period) may have benefited from delayed radical surgery. During the waiting period, the patient should be kept on a minimal handling and stabilizing protocol. In our institute, 24 CDH patients were treated from 1970 to 1995. These patients were divided into two groups : group I (n = 11) was the first stage (1970-1984), group II (n = 13) was the second stage (1985-1995). The total survival rate of these two groups did not improve. However our experience with the last six cases using this stabilizing protocol between 1989 and 1995 suggests that delayed repair surgery for CDH improved the survival rate. The survival rate changed from 33.3% in group I to 44.4% in group II. We report our cases, including clinical status, surgical findings and treatments

    日本における外国人持久走選手への栄養サポートの課題

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    実業団陸上部に在籍するケニア人選手の栄養状況を把握し、在日スポーツ選手のサポートに必要な食事や生活の支援について検討する基礎資料を得ること目的として、本研究を実施した。ケニア人の栄養代謝は日本人のそれよりも低いという研究結果もあり、また、主食となる食品にも違いがあることから、日本の食生活をそのまま選手の栄養サポートに取り入れることは慎重に行われる必要がある。今回実施した調査でも、日本人選手の方がケニア人選手より摂取エネルギー量が多く、ケニア人選手のインタビューからも、食事量が多いという主観的評価があった。そのため、定期的な身体計測や血液検査、パフォーマンスを確認し、食事の内容について評価を行い、ケニア人の体格や代謝に応じた食事が摂られているか、日本で生活を送る上での食生活に対するストレスをどのように発散しているかなど、今後、検討すべき栄養サポート内容を明らかにした
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