著者
橋爪 大輔
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.53, no.5, pp.299-306, 2011-10-31 (Released:2011-11-20)
参考文献数
27

Rietveld method has been widely used for structure refinements as a part of SDPD studies. In this account, practical tips on structure refinements of organic crystal are presented.
著者
池田 卓史
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.53, no.4, pp.231-239, 2011-08-31 (Released:2011-09-15)
参考文献数
39
被引用文献数
1 1

The indexing process, that is determination of unit-cell parameters, is the first important stage of the crystal structure determination from powder diffraction data (SDPD). Accurate Bragg positions (2θ or d values) of 10∼20 peaks picked up by peak-search from low 2θ angle side are indispensable for determination of lattice constants with hkl indices. Subsequently, space group can be estimated according to systematic absences based on obtained lattice constants. Integral intensities of each reflection are tentatively extracted by the whole powder pattern fitting i.e. the Le Bail or Pawley methods. Crystal structure of small organic molecule can be solved by the direct method or the charge flipping algorithm. In this report, the brief summary about indexing and whole pattern fitting was described. Furthermore, some practical examples of SDPD of small organic molecules by the direct method (EXPO2009) and the charge flipping (Superflip) were demonstrated.
著者
藤井 孝太郎 植草 秀裕
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.53, no.3, pp.170-177, 2011-06-30 (Released:2011-07-13)
参考文献数
14
被引用文献数
3 2

Techniques to prepare the sample and strategies to measure powder X-ray diffraction data for ab initio crystal structure analysis of organic and organometallic compound are shown together with an introduction to typical optics of powder X-ray diffractometry.
著者
西野 吉則 木村 隆志 鈴木 明大 城地 保昌 別所 義隆
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.59, no.1, pp.18-23, 2017-02-28 (Released:2017-03-07)
参考文献数
23

X-ray free-electron lasers (XFELs) with femtosecond pulse duration offer an innovative solution to transcend the spatial resolution limitation in conventional X-ray imaging for biological samples and soft matters by clearing up the radiation damage problem using the “diffraction-before-destruction” strategy. Building on this strategy, the authors are developing a method to image solution sample under controlled environment, pulsed coherent X-ray solution scattering (PCXSS), using XFELs and phase retrieval algorithms in coherent diffractive imaging (CDI). This article describes the basics of PCXSS and examples of PCXSS measurement, for a living cell and self-assemblies of gold nanoparticles, performed by the authors using SACLA. An attempt toward the industrial application of PCXSS is also described.
著者
新関 暢一
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.9, no.1, pp.28-34, 1967-02-25 (Released:2010-09-30)
参考文献数
35
著者
大原 高志
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.132-139, 2022-05-31 (Released:2022-06-01)
参考文献数
23

Single-crystal neutron structure analysis is a powerful technique to observe the position of hydrogen atoms in crystals with high accuracy and reliability because of its high sensitivity to hydrogen atoms. In Japan, the development of single-crystal neutron diffractometers for structure analysis has progressed since the 1990s at the JRR-3 research reactor. Subsequently, the construction of J-PARC MLF, a high intense spallation neutron source, started in the 2000s. The author has developed single-crystal neutron diffractometers at JRR-3 and MLF to make the single-crystal neutron structure analysis of organic and organometallic molecular crystals possible. In addition, the author has also been conducting research based on the reliable observation of hydrogen atoms in molecular crystals. This paper will review the recent development of single-crystal neutron diffractometers and studies in which hydrogen atoms play a crucial role.
著者
苙口 友隆 池口 満徳 佐藤 衛
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.55, no.1, pp.24-31, 2013-02-28 (Released:2013-03-07)
参考文献数
19

The combination of small-angle X-ray solution scattering (SAXS) experiments and molecular dynamics (MD) simulations is now becoming a powerful tool to study protein dynamics in solution at an atomic resolution. We have developed a method called MD-SAXS, in which this combination is used with explicit evaluation of X-ray scattering from water molecules hydrating protein molecules. This method offers a link between low-resolution structural information from SAXS and the three-dimensional high-resolution structure. The study using MD-SAXS method revealed the importance of intrinsic dynamics of DNA-binding protein EcoO109I in its function.
著者
木下 是雄
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.29, no.2, pp.69-71, 1987-03-30 (Released:2010-09-30)
参考文献数
8
著者
近藤 次郎 竹中 章郎
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.5, pp.345-351, 2004-10-29 (Released:2010-09-30)
参考文献数
24
被引用文献数
1

Recent human genome projects have revealed that exons encoding proteins count only a few percents, whereas many kinds of repetitive sequences occupy more than 50 % of genome. Some of the latter are related to genetic diseases, but their biological functions and structures are still unknown. Two X-ray structures of a short DNA fragment of d (gcGA [G] 1Agc) show that four base-intercalated duplexes are assembled to form an octaplex at a low K+ concentration, in which the eight G5 residues form a stacked double G-quartet in the central part. At a higher K+ concentration, however, the octaplex is split into just two halves. These structural features suggest a folding process according to a double Greek-key motif for eight tandem repeats of d (ccGA [G] 4Agg) found in Variable number of tandem repeat (VNTR) immediately adjacent to the human pseudoautosomal telomere. Such a packaging of the repeats could facilitate slippage of a certain VNTR sequence during DNA replication, to induce length polymorphism by increasing or decreasing of the repeats.
著者
山本 雅貴 平田 邦生 長谷川 和也
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.64, no.1, pp.2-9, 2022-02-28 (Released:2022-03-04)
参考文献数
37

Since the first crystal structure determination of protein by J. C. Kendrew in 1959, protein crystallography has been playing the leading role in the structural biology by various technology developments. Especially the utilization of synchrotron radiation from the 1990s brought innovative progress in this field on the data quality and the phasing method and had expanded the sample targets including membrane proteins and supra-molecular complexes. Here we will describe the outline and the future prospects of the protein crystallography from the role of synchrotron radiation and SPring-8.
著者
大泊 巌 川原田 洋
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.28, no.2, pp.151-159, 1986-03-30 (Released:2010-09-30)
参考文献数
19

Structures and defects of heterogeneous interfaces have been discussed using the concept of “coherency”which has been applied to interphase boundaries. Interfacial structures have been classified into three kinds, coherent, semicoherent and incoherent interfaces, depending on lattice mismatch. As a case study of the interface with great mismatch of about 10%, the structure of PtSi/ (111) Si interface has been discussed in detail on the basis of HRTEM images. The interface has been found to be atomically abrupt and has atomic steps which increases local coherency between PtSi and Si. (J. Cryst. Soc. Jpn. 28, 151 (1986) ) .
著者
尾勝 圭
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.4, pp.259-260, 2021-12-15 (Released:2021-12-18)
参考文献数
9
著者
重松 秀樹 ゲーレ クリストフ
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.4, pp.262-266, 2021-12-15 (Released:2021-12-18)
参考文献数
4

Effective from 2021B, CryoTEM will be offered in addition to SPring-8 public beamlines for protein crystallography and BioSAXS beamlines. Two CryoTEMs, EM01CT(JEOL CRYO ARM 300), and EM02CT(JEOL CRYO ARM 200)are provided as auxiliary instruments for evaluating the properties of samples for crystallization, such as monodispersity and structural heterogeneity.
著者
三浦 裕行
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.45, no.2, pp.145-147, 2003-04-30 (Released:2010-09-30)
参考文献数
4
被引用文献数
75 79