著者

秋光 純 富本 晃吉

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.34, no.5, pp.273-282, 1992-10-30 (Released:2010-09-30)

参考文献数

26

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The current status of oxide superconductors is briefly reviewed from a crystal structure perspective. Tokura et al. recently classified high-temperature superconductors using block layer concept. We propose a new “layer” concept and discuss the possibility of new block layers by reconstructing the layers. As an example, we present new high-Tc materials containing CO3 by combining an “old” and new block layers recently discovered. Finally, main roles for realizing the high-Tc superconductors are discussed from the structural point of view.

著者

吉田 徹 山田 等仁 津下 英明

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.64, no.1, pp.69-76, 2022-02-28 (Released:2022-03-04)

参考文献数

20

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The iota toxin produced by Clostridium perfringens type E is a binary toxin comprising two independent polypeptides:Ia, an ADP-ribosyltransferase, and Ib, which is involved in cell binding and translocation of Ia across the cell membrane. Binary toxin family includes C. perfringens iota toxin, C. difficile CDT, C. spiroforme CST, C. botulinum C2, and B. anthracis anthrax toxin. Here we introduce the binary toxin complex structures using single-particle Cryo-EM structural analysis and the structural basis of toxin translocation system.

著者

神山 崇

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.40, no.5, pp.301-307, 1998-10-31 (Released:2010-09-30)

参考文献数

17

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入門講座「結晶学の原点を読む」の第2回目は, リートベルト法です.粉末回折法で構造を決定する非常に有力な手段であるリートベルト法は, 現在非常に多くの利用者がおり, 結晶学の分野では欠かせない解析法となっています.この方法の原理は非常に簡単であり, 測定された粉末回折の強度データのパターンと構造モデルから計算された強度のパターンが一致するように最小自乗法でパラメーターを求めるだけです.このように簡単な原理からなっているにもかかわらず, 計算機のプログラムは非常に複雑で多岐に渡っており, 使用している方々のほとんどにとってそのプログラムの中身はまったくブラックボックスであり, かつ出力された結果に対する吟味もどのようにしたら良いかあまりわからず使っている感があります.また, リートベルト自身によるさまざまな物質への適用例は施設報告が多く手に入りにくいものです.そのような中には, 現在の単結晶の実験からみて明らかに間違った結果を出している例も見られます.これも, 当時の技術力と言うよりは, 相転移のような微妙な構造変化の問題を取扱う時, リートベルト法は非常に注意が必要であると言う今日的な問題です.これら, 粉末回折でのリートベルト法の有利な点や適用範囲は何か, また, リートベルト自身がどのような問題点や注意点がこの方法にあると考えていたのかを原著論文で見ることは大変意義があると言えます.今回は, J. Appl. Cryst.に投稿されたリートベルト法の原点とも言える論文を易しく解説していただきます.

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.56, no.3, pp.News3-News3, 2014-06-30 (Released:2014-07-09)

著者

谷口 卓也

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.65, no.2, pp.139-144, 2023-05-31 (Released:2023-06-06)

参考文献数

16

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Organic crystals have presented flexible features in contrast with inorganic crystals, and are expected for the future applications of optoelectronics and active matters. Pharmaceuticals are also the utilization of the organic crystal family. This article presents the basis of the data science in organic crystals, and a few examples of application of my research. An attempt is to screen the structural phase transition of organic crystals, and another topic is to compare structural representation of molecular and crystal structures regressed by graph neural network.

著者

上村 みどり

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.65, no.1, pp.51-54, 2023-02-28 (Released:2023-03-08)

参考文献数

10

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The paradigm shift in drug discovery that began in the early 1990s was the development of Structure Based Drug Design(SBDD)as a means of rational drug design for disease targets. The greatest advantage of X-ray analysis is that once the crystal structure is obtained, structural information can be fed back very quickly under almost the same conditions for soaking and co-crystallization, contributing to lead optimization in the early stages of drug discovery. In addition, it is unique in that it covers target molecules from small molecular weights(20-30 kDa)to large molecular weights(100 kDa~). On the other hand, it has many weak points such as dynamic structure close to the physiological state, identification of hydrogen atoms, and acquisition of charge information, which, when combined with multiple methods in a complementary manner, will contribute to a significant reduction in the lead optimization period in the future.

著者

ネスポロ マッシモ

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.59, no.4, pp.150-158, 2017-08-31 (Released:2017-08-31)

参考文献数

14

被引用文献数

2

著者

草野 圭弘 福原 実

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.56, no.3, pp.179-185, 2014-06-30 (Released:2014-07-09)

参考文献数

25

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Bizen stoneware, with the characteristic reddish hidasuki or “fire-marked” pattern, is one of Japan's best known traditional ceramic works of art. We investigated the microstructure and color-formation process in Bizen stoneware, and discovered that the hidasuki pattern resulted from the precipitation of corundum (α-Al2O3) and the subsequent epitaxial growth of hematite (α-Fe2O3) around it in a ~50 µm-thick liquid specifically formed in the ceramic surface. The epitaxial composites include hexagonal plate-like α-Fe2O3/α-Al2O3/α-Fe2O3 sandwiched particles. At low oxygen partial pressures, α-Fe coated graphite, Fe3P and ε-Fe2O3 were also formed to appear.

著者

東 晃

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.14, no.6, pp.274-285, 1972-12-25 (Released:2010-09-30)

参考文献数

37

被引用文献数

1 2

著者

大場 茂

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.59, no.6, pp.284-292, 2017-12-31 (Released:2017-12-31)

参考文献数

14

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SHELXT is a revolutionary program which solves the structure assuming space group P1, and determines the space group type based on the assigned Laue group and calculated P1 phase angles. The background and procedures of the computation will be summarized, and important points to check the results will be noted.

著者

都築 誠二 本田 一匡

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.46, no.2, pp.165-171, 2004-04-30 (Released:2010-09-30)

参考文献数

27

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Ab initio molecular orbital calculation is becoming a powerful tool for studying inter-molecular interactions in crystals. The effects of basis set and electron correlation and the performance of density functional methods are reviewed. Model chemistry calculations and classification of intermolecular interactions are briefly mentioned. Some examples of high-level ab initio computations of intermolecular interactions are also presented.

著者

仁田 勇

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.19, no.5, pp.269-276, 1977 (Released:2010-09-30)

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Reminiscences are given out of the early stages of the development in x-ray crystallography, both in Japan and abroad. Activities in Prof. Ewald's school in Germany, those of Prof. Bragg's in England, Prof. Terada's and Nishikawa's in Japan are described.Prof. Nishikawa's contribution concerning the space group theory in the structure analysis is brought to attention. Early works of Prof. Nitta on organic crystals are also described.Some x-ray photographs taken by Prof. Nishikawa and Prof. Nitta in the early period from 1913 to 1925 are reproduced. (abstract by the editor)

著者

張 志寛

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.3, pp.181-182, 2021-08-31 (Released:2021-09-02)

参考文献数

10

著者

清水 伸隆

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.65, no.1, pp.42-50, 2023-02-28 (Released:2023-03-08)

参考文献数

68

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Small-angle X-ray scattering(SAXS)for solution samples of biological macromolecules, recently called BioSAXS, has been used to estimate the conformational state of flexible proteins and unstable protein complexes in solution. With the advent of a new technique called SEC-SAXS, it has become easier to obtain structural information derived only from the target molecule, and it is now possible to estimate the structural state in solution with higher accuracy than 10 years ago. In this article, I will introduce not only some characteristic examples of BioSAXS analysis, but also the recently developing technique of time-resolved measurement.

著者

高場 圭章

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.64, no.2, pp.115-116, 2022-05-31 (Released:2022-06-01)

参考文献数

19

著者

長岡 伸一 西奥 義憲 小原 敬士 向井 和男

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.40, no.1, pp.119-123, 1998-02-28 (Released:2010-09-30)

参考文献数

40

被引用文献数

1

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Since a vitamin E radical produced by the antioxidant reaction of vitamin E causes damage to vital functions, ubiquinol and vitamin C regenerate a vitamin E molecule from a vitamin E radical in vivo. The kinetic studies of the regeneration reactions have been carried out in solutions by means of stopped-flow spectroscopy. Substantial deuterium kinetic-isotope-effects on the second-order rate constants have been observed in both the reactions of ubiquinol and vitamin C. Furthermore, a deviation from a linear relationship in the Arrhenius plot has been observed in the reaction of ubiquinol. These results suggest that the tunneling effect plays an important role in the regeneration reactions in various tissues and mitochondria.

著者

宋 致宖 村田 和義

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.2, pp.80-88, 2021-05-31 (Released:2021-06-05)

参考文献数

50

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About 40 years ago, the basic concept of cryo-electron microscopy was introduced, where biological specimens were kept close to nature state by being embedded in vitreous ice and observed directly with electron microscope. Since then, technology and equipment have improved significantly, making it now possible to determine the atomic coordinates of many biomolecules. Here, we will introduce the latest structural study of biomolecules using single particle cryo-electron microscopy.

著者

近藤 次郎

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.60, no.2-3, pp.121-128, 2018-05-31 (Released:2018-06-02)

参考文献数

23

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DNA is very attractive as bio-nanomaterials, since it is chemically stable, biocompatible, less toxic, environmentally friendly and easy to synthesize. In addition, the discovery of metal-mediated base pairs, such as T-Hg(II)-T and C-A(gI)-C, has inspired scientists to develop several nanodevices including heavy metal sensor and trapping beads. Recently, we have successfully developed a silver-DNA hybrid nanowire composed only of silver-mediated base pairs, in which Ag(I)make uninterrupted one-dimensional array along the DNA helical axis. In addition, its structure was solved by high-resolution X-ray crystallography. In this article, I present a variety of complicated and beautiful DNA structures and discuss the future outlook of “DNA structural bio-nanotechnology”.

著者

興野 純

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.49, no.6, pp.321-327, 2007-12-25 (Released:2010-09-30)

参考文献数

25

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Light-induced phase transformation from realgar to pararealgar has been studied by means of single-crystal X-ray diffraction and X-ray photoelectron spectroscopy. The photochemical degradation causes the increase of As4S4 intermolecular distances and the production of the As4S5 molecules. The results suggest the following cyclic process. 1st : an S atom in the As4S5 is released from one of the As-S-As linkages in As4S5 which becomes the As4S4 pararealgar molecule, 2nd : the free S atom is re-attached to another As4S4 realgar molecule and reproduces an As4S5 molecule, and 3rd : the As4S5 is again divided into an As4S4 pararealgar molecule and an S atom.

著者

西山 裕介

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.64, no.3, pp.201-202, 2022-08-31 (Released:2022-09-02)

参考文献数

14