著者

Ryota Kasugai Yoshifumi Kadowaki Yasunori Yokoyama Naoyuki Katayama Yoshihiko Okamoto Koshi Takenaka

出版者

The Japan Institute of Metals and Materials

雑誌

MATERIALS TRANSACTIONS (ISSN:13459678)

巻号頁・発行日

vol.64, no.3, pp.638-642, 2023-03-01 (Released:2023-02-25)

参考文献数

30

被引用文献数

5

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For Mg-doped Zn2P2O7, this systematic investigation of co-doping onto Zn sites has elucidated specific effects on negative thermal expansion (NTE). The low-cost and low-environmental-impact NTE material Zn2−xMgxP2O7 shows large NTE in a temperature range including room temperature for x = 0.4. Although Mg doping broadens the operating-temperature window, it remains several dozen degrees wide. Moreover, the total volume change related to NTE becomes less than that of the Zn2P2O7 parent material. Findings obtained from this study demonstrate that co-doping of Mg and of another element onto the Zn site is effective for achieving simultaneous expansion of the operating-temperature window and maintenance of the volume change related to NTE. One illustrative case is that Zn1.64Mg0.30Al0.06P2O7 has a large negative coefficient of linear thermal expansion of about −65 ppm/K at temperatures of 300–375 K. In fact, at temperatures high above room temperature, Zn1.64Mg0.30Al0.06P2O7 powder shows better thermal expansion compensation capability than the composition without Al. The Al-doped phosphates are expected to have broad practical application because of their performance, cost, and environmental load characteristics.

著者

Kei Suzuki Akiko Nakamura Tomoyuki Enokiya Yoshiaki Iwashita Eri Tomatsu Yuichi Muraki Toshihiro Kaneko Masahiro Okuda Naoyuki Katayama Hiroshi Imai

出版者

一般社団法人 日本内科学会

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

vol.52, no.14, pp.1641-1645, 2013 (Released:2013-07-15)

参考文献数

20

被引用文献数

4 13

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We herein report the first case of septic arthritis caused by rmpA-positive hypermucoviscous community-acquired K. pneumoniae that followed urosepsis in a 65-year-old Japanese woman. The patient responded well to drainage of the abscesses and treatment with cefazolin. Although this virulent phenotype of K. pneumoniae has been primarily reported in Hong Kong, we confirmed that 18/50 isolates obtained in our hospital over the past five years displayed the hypermucoviscous phenotype. Therefore, clinicians should consider the possibility of an increasing prevalence of rmpA-positive hypermucoviscous K. pneumoniae infection in Japan and be particularly vigilant for invasive clinical manifestations, even in patients with urinary tract infections.