Crystal transition between hydrate and anhydrous β-chitin monitored by synchrotron X-ray fiber diffraction

2010 ◽  
Vol 79 (4) ◽  
pp. 882-889 ◽  
Author(s):  
Kayoko Kobayashi ◽  
Satoshi Kimura ◽  
Eiji Togawa ◽  
Masahisa Wada
Keyword(s):  
X Ray ◽  
Fiber Diffraction ◽  
Crystal Transition

Crystal Transition and Drug-excipient Compatibility of Clarithromycin in Sustained Release Tablets

2020 ◽  
Vol 16 (7) ◽  
pp. 950-959
Author(s):  
Yu Li ◽  
Xiangwen Kong ◽  
Fan Hu
Keyword(s):  
Sustained Release ◽  
Powder Diffraction ◽  
Magnesium Stearate ◽  
Influential Factor ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sustained Release Tablets ◽  
Crystal Transition ◽  
Excipient Compatibility

Background: Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release tablets were found. Objective: The aim of this study was to find the influential factor of the crystal transition of clarithromycin in preparation process of sustained-release tablets and to investigate the possible interactions between the clarithromycin and pharmaceutical excipients. Methods and Results: The crystal transition of active pharmaceuticals ingredients from form II to form I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction. The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder diffraction were used for assessing the compatibility between clarithromycin and several excipients as magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline cellulose. All of these methods showed compatibilities between clarithromycin and the selected excipients. Alcohol prescription simulation was also done, which showed incompatibility between clarithromycin and concentration alcohol. Conclusion: It was confirmed that the reason for the incompatibility of clarithromycin with high concentration of alcohol was crystal transition.

Cross-β Spine Architecture of Fibrils Formed by the Amyloidogenic Segment NFGSVQFV of Medin from Solid-State NMR and X-ray Fiber Diffraction Measurements†

Biochemistry ◽  
2009 ◽  
Vol 48 (14) ◽  
pp. 3089-3099 ◽  
Author(s):  
Jillian Madine ◽  
Alastair Copland ◽  
Louise C. Serpell ◽  
David A. Middleton
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
X Ray ◽  
Fiber Diffraction

scholarly journals Distinct Structural Changes Detected by X-Ray Fiber Diffraction in Stabilization of F-Actin by Lowering pH and Increasing Ionic Strength

2001 ◽  
Vol 80 (2) ◽  
pp. 841-851 ◽  
Author(s):  
Toshiro Oda ◽  
Kouji Makino ◽  
Ichiro Yamashita ◽  
Keiichi Namba ◽  
Yuichiro Maéda
Keyword(s):  
Ionic Strength ◽  
Structural Changes ◽  
X Ray ◽  
Fiber Diffraction

scholarly journals Structural Changes of Microtubules During GTP Hydrolysis Revealed by X-Ray Fiber-Diffraction

2010 ◽  
Vol 98 (3) ◽  
pp. 362a
Author(s):  
Shinji Kamimura ◽  
Hiroyuki Iwamoto ◽  
Daisuke Miyashiro
Keyword(s):  
Structural Changes ◽  
Gtp Hydrolysis ◽  
X Ray ◽  
Fiber Diffraction

scholarly journals The 3D structure of fibrous material is fully restorable from its X-ray diffraction pattern

IUCrJ ◽  
2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Hiroyuki Iwamoto
Keyword(s):  
Diffraction Pattern ◽  
Fibrous Material ◽  
3D Structure ◽  
Wide Field ◽  
Fibrous Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fiber Diffraction ◽  
Puzzle Solving ◽  
Diffraction Patterns

X-ray fiber diffraction is potentially a powerful technique to study the structure of fibrous materials, such as DNA and synthetic polymers. However, only rotationally averaged diffraction patterns can be recorded and it is difficult to correctly interpret them without the knowledge of esoteric diffraction theories. Here we demonstrate that, in principle, the non-rotationally averaged 3D structure of a fibrous material can be restored from its fiber diffraction pattern. The method is a simple puzzle-solving process and in ideal cases it does not require any prior knowledge about the structure, such as helical symmetry. We believe that the proposed method has a potential to transform the fiber diffraction to a 3D imaging technique, and will be useful for a wide field of life and materials sciences.

scholarly journals 1P157 Dispositional and Conformafonal Changes of Myosin Crossbridges in Skeletal Musde Contraction and Regulation by X-ray Fiber Diffraction(Muscle-muscle proteins and contraction,Poster Presentations)

2007 ◽  
Vol 47 (supplement) ◽  
pp. S62
Author(s):  
Kanji Oshima ◽  
Yasunori Takezawa ◽  
Yasunobu Sugimoto ◽  
Thomas C. Irving ◽  
Katsuzo Wakabayashi
Keyword(s):  
Muscle Proteins ◽  
X Ray ◽  
Fiber Diffraction ◽  
Poster Presentations

Evidence for room temperature mesomorphism in a mixed-valent diruthenium(II,III) quintapalmitoleate polymer

1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Powder Diffraction ◽  
Strong Evidence ◽  
Room Temperature ◽  
Variable Temperature ◽  
Mixed Valence ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystal Transition

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.

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