Determining the mechanisms of deformation in flexible crystals using micro-focus X-ray diffraction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Amy J Thompson ◽  
Anna Worthy ◽  
Arnaud Grosjean ◽  
Jason Price ◽  
John C McMurtrie ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
First Report ◽  
A Priority ◽  
Mechanisms Of Deformation

While the first report of molcular crystals that could bend without breaking was well over a decade ago, the development of suitable characterisation tools remains a priority. Due to the...

Crystal Structure of a Novel Furo-Furan Lactone from Heliotropium eichwaldi

2012 ◽  
Vol 67 (3) ◽  
pp. 269-271
Author(s):  
Sadiqa Firdous ◽  
Nida Hassan Ansari ◽  
Seik Weng Ngb ◽  
Sammer Yousuf ◽  
Abdul Malik
Keyword(s):  
Crystal Structure ◽  
Ethyl Acetate ◽  
Soluble Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report ◽  
First Time

A novel furo-furan lactone 1 has been isolated as fine needles from the ethyl acetate-soluble fraction of Heliotropium eichwaldi. This is the first report of any furo-furan from the genus Heliotropium. β -Sitosterol 3-O-β -D-glucoside 2 has also been obtained for the first time from this source. The structure of 1 was elucidated by X-ray diffraction studies.

The Great Barrier Reef Expedition 1928–29: The crystal structure and occurrence of weddellite, ideally CaC2O4·2.5H2O, from the Low Isles, Queensland

2016 ◽  
Vol 80 (2) ◽  
pp. 399-406 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy
Keyword(s):  
Crystal Structure ◽  
Coral Reef ◽  
Low Temperature ◽  
Great Barrier Reef ◽  
Single Crystal ◽  
Structure Study ◽  
Barrier Reef ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report

Abstract“Envelope crystals” collected during The Great Barrier Reef Expedition in May 1929 have been studied using low-temperature synchrotron single-crystal X-ray diffraction. The crystals are shown to be weddellite, with the largest content of zeolitic water reported to date. A new H2O site has been located within the crystal structure. Study of the crystals show that the end-member formula for weddellite should be reported as CaC2O4·(2.5 – x)H2O, where 0≤x≤ 0.25, instead of CaC2O4·(2H2O or CaC2O4·(2 + x )H2O. This is also the first report of weddellite occurring in a coral reef.

scholarly journals Zopfiellasins A–D, Two Pairs of Epimeric Cytochalasins from Kiwi-Associated Fungus Zopfiella sp. and Their Antibacterial Assessment

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5611
Author(s):  
Jie-Yu Zhang ◽  
Juan He ◽  
Zheng-Hui Li ◽  
Tao Feng ◽  
Ji-Kai Liu
Keyword(s):  
Antibacterial Activity ◽  
Data Analysis ◽  
Single Crystal ◽  
Pseudomonas Syringae ◽  
Spectroscopic Data ◽  
Antibacterial Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report ◽  
The Absolute

In our continuous search for antibacterial agents against Pseudomonas syringae pv. actinidiae (Psa) from kiwi-associated fungi, two pairs of epimeric cytochalasins, zopfiellasins A–D (1–4), were characterized from the fungus Zopfiella sp. The structures were established on the basis of spectroscopic data analysis, while the absolute configurations were determined by single-crystal X-ray diffraction. Compounds 1 and 3 exhibited antibacterial activity against Psa with MIC values of 25 and 50 μg/mL, respectively. This is the first report of anti-Psa activity of cytochalasin derivatives.

scholarly journals Potent Phytotoxic Harziane Diterpenes from a Soft Coral-Derived Strain of the Fungus Trichoderma harzianum XS-20090075

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dong-Lin Zhao ◽  
Lu-Jia Yang ◽  
Ting Shi ◽  
Chao-Yi Wang ◽  
Chang-Lun Shao ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Trichoderma Harzianum ◽  
Spectroscopic Data ◽  
Soft Coral ◽  
Lactone Ring ◽  
Ring System ◽  
Future Research ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report

Abstract Two new harziane diterpene lactones, possessing a 6/5/7/5-fused carbocyclic core containing a lactone ring system, harzianelactones A and B (1 and 2), and five new harziane diterpenes, harzianones A–D (3–6) and harziane (7), were isolated from the soft coral-derived fungus Trichoderma harzianum XS-20090075. Their structures were determined by extensive NMR spectroscopic data, ECD and OR calculations, as well as X-ray diffraction. The isolated compounds exhibited potent phytotoxicity against seedling growth of amaranth and lettuce. Harziane diterpenes were rarely reported for their remarkably bioactivities, and it was the first report to study the phytotoxicity of harziane diterpenes, which provide a new application of such compounds in agriculture for future research.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

Sign in / Sign up

Export Citation Format

Share Document