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Suk-Ho Kang, Juhea Chang, Ho-Hyun Son
OBJECTIVES: There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. MATERIALS AND METHODS: Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment...
August 2013: Restorative Dentistry & Endodontics
Maureen B Quin, Grayson Wawrzyn, Claudia Schmidt-Dannert
Basidiomycetes produce a wide range of industrially relevant natural products. One of the main classes of natural products isolated from fungi are terpenoids, a highly diverse group of secondary metabolites, many of which are bioactive and have been adapted for pharmaceutical purposes. The discovery of a suite of novel sesquiterpene synthases from Omphalotus olearius via genome sequencing and bioinformatic analyses has recently been described. Here, the expression, purification and crystallization of one of these enzymes (Omp6), a protoilludene synthase, is reported...
May 1, 2013: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
P Oberta, Y Platonov, U Flechsig
The X-ray optics group at the Swiss Light Source in co-operation with RIT (Rigaku Innovative Technologies) have investigated seven different multilayer samples. The goal was to find an ideal multilayer structure for the energy range between 6 keV and 20 keV in terms of energy resolution and reflectivity. Such multilayer structures deposited on substrates can be used as X-ray monochromators or reflecting synchrotron mirrors. The measured reflectivities agree with the simulated ones. They cover a reflectivity range from 45% to 80% for energies between 6 keV and 10 keV, and 80% to 90% for energies between 10 keV and 20 keV...
September 2012: Journal of Synchrotron Radiation
David Salas-de la Cruz, Jeffrey G Denis, Matthew D Griffith, Daniel R King, Paul A Heiney, Karen I Winey
We have designed, constructed, and evaluated an environmental chamber that has in situ dynamic control of temperature (25 to 90 °C) and relative humidity (0% to 95%). The compact specimen chamber is designed for x-ray scattering in transmission with an escape angle of 2θ = ±30°. The specimen chamber is compatible with a completely evacuated system such as the Rigaku PSAXS system, in which the specimen chamber is placed inside a larger evacuated chamber (flight path). It is also compatible with x-ray systems consisting of evacuated flight tubes separated by small air gaps for sample placement...
February 2012: Review of Scientific Instruments
Sudipta Bhattacharyya, Debajyoti Dutta, Ananta Kumar Ghosh, Amit Kumar Das
The gene product of the sas2203 ORF of Staphylococcus aureus MSSA476 encodes a 30 kDa molecular-weight protein with a high sequence resemblance (29% identity) to tetrameric inositol monophosphatase from Thermotoga maritima. The protein was cloned, expressed, purified to homogeneity and crystallized. Crystals appeared in several conditions and good diffraction-quality crystals were obtained from 0.2 M Li(2)SO(4), 20% PEG 3350, 0.1 M HEPES pH 7.0 using the sitting-drop vapour-diffusion method. A complete diffraction data set was collected to 2...
April 1, 2011: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
Hyung-Tae Kim, Jung-Suk Han, Jae-Ho Yang, Jai-Bong Lee, Sung-Hun Kim
STATEMENT OF PROBLEM: Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE: The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM)...
November 2009: Journal of Advanced Prosthodontics
S Kameoka, K Matsumoto, Y Kai, Y Yonehara, Y Arai, K Honda
The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague-Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0...
October 2010: Dento Maxillo Facial Radiology
Chun-Yan Cao, Xiao-Guang Yu, Wei-Ping Qin, Ji-Sen Zhang
Series of Tm3+/Yb3+ co-doped GdF3 powders were synthesized through an easy and mild hydrothermal method. The phase and purity of powders were characterized by powder X-ray diffraction (XRD) (Rigaku RU-200b). The morphologies of the samples were characterized by field emission scanning electron microscopy (FE SEM) (Hitachi S-4800). The ultraviolet (UV) up-conversion (UC)emission spectra were recorded by a fluorescence spectrophotometer (Hitachi F-4500) with a 980 nm semiconductor continuous wave laser diode as the excitation source...
March 2010: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
Sudipta Bhattacharyya, Debajyoti Dutta, Ananta Kumar Ghosh, Amit Kumar Das
An atypical two-cysteine peroxidase, SAOUHSC_01822, from the virulent Staphylococcus aureus strain NCTC 8325 plays a major role in the response of the bacterium to oxidative stress. The protein was cloned, expressed, purified to homogeneity and crystallized. The protein was crystallized from 2 M ammonium sulfate, 0.1 M Na HEPES pH 7, 2%(v/v) PEG 400. A complete diffraction data set was collected to 2.3 angstrom resolution using a Rigaku MicroMax HF007 Cu K alpha X-ray generator and a Rigaku R-AXIS IV(+)(+) detector...
November 1, 2009: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
Elizabeth A Zhurova, Vladimir V Zhurov, Deepak Chopra, Adam I Stash, A Alan Pinkerton
The biological function of steroidal estrogens is related to their electronic properties. An experimental charge density study has been carried out on 17alpha-estradiol and compared to similar studies on more potent estrogens. High accuracy X-ray data were measured with a Rigaku rotating anode diffractometer equipped with an R-Axis Rapid curved image plate detector at 20 K. The total electron density in the 17alpha-estradiol x 1/2 H(2)O crystal was modeled using the Hansen-Coppens multipole model. Topological analysis of the electron density based on Bader's QTAIM theory was performed...
December 2, 2009: Journal of the American Chemical Society
M Iijima, W A Brantley, W H Guo, W A T Clark, T Yuasa, I Mizoguchi
OBJECTIVES: Employ conventional X-ray diffraction (XRD) to analyze three clinically important nickel-titanium orthodontic wire alloys over a range of temperatures between 25 and -110 degrees C, for comparison with previous results from temperature-modulated differential scanning calorimetry (TMDSC) studies. METHODS: The archwires selected were 35 degrees C Copper Ni-Ti (Ormco), Neo Sentalloy (GAC International), and Nitinol SE (3M Unitek). Neo Sentalloy, which exhibits superelastic behavior, is marketed as having shape memory in the oral environment, and Nitinol SE and 35 degrees C Copper Ni-Ti also exhibit superelastic behavior...
November 2008: Dental Materials: Official Publication of the Academy of Dental Materials
Eric J Yearley, Elizabeth A Zhurova, Vladimir V Zhurov, A Alan Pinkerton
In a continuing effort to determine a relationship between the biological function and the electronic properties of steroidal and nonsteroidal estrogens by analysis of the submolecular properties, an experimental charge density study has been pursued on the nonsteroidal phytoestrogen, genistein. X-ray diffraction data were obtained using a Rigaku R-Axis Rapid high-power rotating anode diffractometer with a curved image plate detector at 20(1) K. The total electron density was modeled using the Hansen-Coppens multipole model...
December 5, 2007: Journal of the American Chemical Society
Feng Yu, Jiaping Song, Chunyan Xu, Yu Ding, Xiaojian Hu, Jianhua He, Zhihong Zhang
The C-terminal 232-419 amino acids fragment of endonuclease Sau3AI has been successfully expressed in Escherichia coli with 6 His at its N-terminal. After purification and crystallization, one completed 2.8 A data set was collected using a Rigaku R-AXIS IV++ diffractometer. The plate-like crystals belong to orthorhombic space group P2(1)2(1)2(1) with the cell dimension of a = 34.75, b = 76.82, c = 123.59A and contain one molecule per asymmetric unit.
2006: Protein and Peptide Letters
Elizabeth A Zhurova, Chérif F Matta, Nan Wu, Vladimir V Zhurov, A Alan Pinkerton
The electron density and the electrostatic potential (ESP) distributions of estrone have been determined using X-ray diffraction analysis and compared with theoretical calculations in the solid and gas phases. X-ray diffraction measurements are performed with a Rigaku Rapid rotating anode diffractometer at 20 K. The electron density in the estrone crystal has been described with the multipole model, which allowed extensive topological analysis and calculation of the ESP. From DFT calculations in the solid state a theoretical X-ray diffraction data set has been produced and treated in the same way as the experimental data...
July 12, 2006: Journal of the American Chemical Society
JianJun Zhang, Ge Gao, Ming Zhang, Dan Zhang, ChunLei Wang, DaCheng Zhao, FengQi Liu
The hybrid microspheres of ZnO/PS with different core-shell structures were prepared in miniemulsion polymerization. 3-(trimethoxysilyl)propyl methacrylate (MPS) was used as a functional co-monomer to enhance the surface polarity of ZnO nanoparticles and to prevent water from quenching the luminescent properties of ZnO. The morphology of hybrid particles was examined with a transmission electron microscope. The luminescence spectra were measured using a Shimadzu RF-5301 PC spectrofluorimeter (Xe source) at room temperature...
September 1, 2006: Journal of Colloid and Interface Science
Stephen P Muench, Sean T Prigge, Liqun Zhu, Michael J Kirisits, Craig W Roberts, Sarah Wernimont, Rima McLeod, David W Rice
The protozoan parasite Toxoplasma gondii is the causative agent of one of the most widespread parasitic infections of man and is a leading cause of congenital neurological birth defects and the third most common cause of food-borne deaths in the United States. Despite this, to date no drugs are available that provide a fully effective treatment. Recently, the antibacterial agent triclosan was shown to inhibit the fatty-acid biosynthesis pathway in T. gondii and to interact with the enoyl reductase (ENR). In order to analyse the potential of triclosan as a lead compound targeting T...
June 1, 2006: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
Chomphunuch Songsiriritthigul, Jirundon Yuvaniyama, Robert C Robinson, Archara Vongsuwan, Heino Prinz, Wipa Suginta
Chitinase A of Vibrio carchariae was expressed in Escherichia coli M15 host cells as a 575-amino-acid fragment with full enzymatic activity using the pQE60 expression vector. The yield of the highly purified recombinant protein was approximately 70 mg per litre of bacterial culture. The molecular mass of the expressed protein was determined by HPLC/ESI-MS to be 63 770, including the hexahistidine tag. Crystals of recombinant chitinase A were grown to a suitable size for X-ray structure analysis in a precipitant containing 10%(v/v) PEG 400, 0...
October 1, 2005: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
Amrita Madabushi, Sibani Chakraborty, S Zoë Fisher, José C Clemente, Charles Yowell, Mavis Agbandje-McKenna, John B Dame, Ben M Dunn, Robert McKenna
Plasmepsin 4 from the malarial parasite Plasmodium malariae (PmPM4) is a member of the plasmepsins (Plasmodium pepsins), a subfamily of the pepsin-like aspartic proteases whose ortholog in the malarial parasite P. falciparum is involved in hemoglobin digestion in its digestive vacuole. Crystals of PmPM4 in complex with the small-molecule inhibitor AG1776 have been grown from a precipitant of 15% PEG 4000 and 200 mM ammonium sulfate in 100 mM sodium acetate pH 4.5. X-ray diffraction data were collected on a Rigaku rotating-anode generator from a single crystal under cryoconditions, with a maximal useful diffraction pattern to 3...
February 1, 2005: Acta Crystallographica. Section F, Structural Biology and Crystallization Communications
Joyanne A Kelly, Elizabeth A Williams, Matthew C J Wilce
The p13(suc1) is the fission yeast member of the Cks (Cdc28-dependant kinase subunit) family of proteins. The Cks proteins bind to and are required for the function of cyclin-dependant kinase (Cdk) proteins during cell cycle progression in eukaryotic cells. Two conformations of Cks have been detected crystallographically; a compact monomer with the C-terminal fourth beta-strand inserted into the core of the molecule between strands 2 and 3, and a strand-exchanged dimer where the fourth beta-strand is inserted into the core of the dimer partner in an equivalent position...
July 2005: European Biophysics Journal: EBJ
X Zhang, B Tan
X-Ray Kbeta emission spectra of chromium and some of their compounds were studied by conventional XRF spectrometer Rigaku 3080 E1 and PEAKFIT spectrum analyzing programs. Some qualitative and quantitative relations were obtained between the true spectrum profile and its parameters (peak position, peak top intensity, FWHM and asymmetry indices) and chemical state by data processing technique. And making use of these relationship, the chemical state distribution were analyzed of chemical chromate treatment film, stainless steel...
February 1998: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
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