The Role of Chemical Substances in Classic and Modern Sialography Technique and applications

2018 ◽  
Vol 68 (12) ◽  
pp. 2829-2831
Author(s):  
Danisia Haba ◽  
Cristian Budacu ◽  
Mihai Constantin ◽  
Victor Vlad Costan ◽  
Alexandru Nemtoi
Keyword(s):  
Three Dimensional ◽  
Cone Beam ◽  
Prospective Clinical Study ◽  
Two Dimensional ◽  
Chemical Substances ◽  
X Ray ◽  
Time Period ◽  
Plain Image ◽  
Oral And Maxillofacial Surgeon

The purpose of this study was to assess the role of a chemical contrast medium used in plain x ray and CBCT (cone beam computed tomography) sialography imaging in the detection of different changes associated with lesions of salivary glands. 20 subjects were recruited into this prospective clinical study over a 1 year time period. Sialography was performed by an oral and maxillofacial surgeon. A lateral skull plain image was then made and a three-dimensional scanning using a CBCT machine. The imaging volume was centred on the gland of interest. The lateral skull plain images represented the two-dimensional part of the study, and these were used for comparison with the three-dimensional investigation, the CBCT images.

Pore geometry in woven fiber structures: 0°/90° plain-weave cloth layup preform

1998 ◽  
Vol 13 (5) ◽  
pp. 1209-1217 ◽  
Author(s):  
S-B. Lee ◽  
S. R. Stock ◽  
M. D. Butts ◽  
T. L. Starr ◽  
T. M. Breunig ◽  
...  
Keyword(s):  
Gas Flow ◽  
Three Dimensional ◽  
Pore Geometry ◽  
Two Dimensional ◽  
Transverse Distribution ◽  
One Dimensional ◽  
X Ray ◽  
Woven Structures ◽  
Flow Through

Composite preform fiber architectures range from the very simple to the complex, and the extremes are typified by parallel continuous fibers and complicated three-dimensional woven structures. Subsequent processing of these preforms to produce dense composites may depend critically on the geometry of the interfiber porosity. The goal of this study is to fully characterize the structure of a 0°/90° cloth layup preform using x-ray tomographic microscopy (XTM). This characterization includes the measurement of intercloth channel widths and their variability, the transverse distribution of through-cloth holes, and the distribution of preform porosity. The structure of the intercloth porosity depends critically on the magnitude and direction of the offset between adjacent cloth layers. The structures observed include two-dimensional networks of open pipes linking adjacent holes, arrays of parallel one-dimensional pipes linking holes, and relatively closed channels exhibiting little structure, and these different structures would appear to offer very different resistances to gas flow through the preform. These measurements, and future measurements for different fiber architectures, will yield improved understanding of the role of preform structure on processing.

Instrument Design and Image Reconstruction For A Laboratory X-Ray Microtomograph

1990 ◽  
Vol 48 (1) ◽  
pp. 518-519
Author(s):  
Roger H. Johnson ◽  
Alan C. Nelson ◽  
David H. Burns
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Thin Foil ◽  
Cone Beam ◽  
X Rays ◽  
Two Dimensional ◽  
Rotating Shaft ◽  
Data Set ◽  
Solid State Detector ◽  
X Ray

X-ray microscopy has received considerable attention over the years, since it has the potential of producing high-resolution images of thick specimens in air. We are developing an x-ray microtomograph for three-dimensional imaging of small biological specimens. The instrument, shown in Figure 1, has much in common with projection x-ray microscopes of decades past, but incorporates several technological advances of recent years to partially overcome the limitations of the older instruments. The most important of these are the use of a planar solid-state detector and the provision for volume reconstruction. We describe the design for a relatively low-cost instrument intended for 3-D imaging of biological specimens up to ten cubic millimeters in size.The x-ray source for the microtomograph consists of a modified SEM. The electron beam, in spot mode and focused to about ten nanometers, impinges on a thin foil target to produce an emergent, low-intensity cone beam of characteristic and Bremsstrahlung x-rays. The foil resides in close proximity to an optional aluminum filter and a thin beryllium window which terminates the evacuated electron column. The specimen is mounted on a precision rotating shaft within two millimeters of the target foil. A two-dimensional detector is placed ten to forty centimeters from the sample, providing direct projection magnifications of up to 200 times. Two-dimensional projection views are collected at each of many angular orientations as the sample is rotated through 360 degrees. Cone beam backprojection algorithms are then applied to reconstruct a threedimensional data set.

Two New Three-Dimensional Networks Constructed on Polyoxovanadates

2007 ◽  
Vol 60 (11) ◽  
pp. 871 ◽  
Author(s):  
Yan-fei Qi ◽  
Dongrong Xiao ◽  
Enbo Wang ◽  
Zhiming Zhang ◽  
Xinlong Wang
Keyword(s):  
Thermogravimetric Analysis ◽  
Rare Case ◽  
Three Dimensional ◽  
Network Connectivity ◽  
Two Dimensional ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray

To investigate the role of polyoxovanadates in network connectivity, two new organic–inorganic hybrid vanadates with three-dimensional entangled coordination frameworks, namely [Cu2(biim)3V4O12] 1 and [Co2(biim)3V4O12]·4H2O 2 have been synthesized and characterized by infrared (IR), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Crystal data for compound 1: triclinic, P-1, a 9.504(2), b 10.650(2), c 11.993(2) Å; α 72.13(3), β 76.02(3), γ 65.40(3)°; V 1041.4(4) Å3, Z 2, R(final) 0.0492. Crystal data for compound 2: triclinic, P-1, a 9.037(3), b 10.577(2), c 11.9470(2) Å; α 87.80(3), β 81.71(3), γ 85.29(3)°; V 1125.8(4) Å3, Z 1, R(final) 0.0774. Compound 1 is a three-dimensional inclined hetero-catenated framework designed from two two-dimensional sub-layers, [Cu(biim)V4O12] and [Cu(biim)2]. Compound 2 is a rare case of a self-catenated ‘ilc’ network that displays an unusual 424·5·63 topology with the binuclear {Co2O4N6} units as eight-connected nodes.

scholarly journals Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev
Keyword(s):  
Hydrogen Bonds ◽  
Dissolution Rate ◽  
Aqueous Medium ◽  
Acid Amide ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Reference Drug ◽  
X Ray ◽  
Time Period ◽  
Solid Form

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.

scholarly journals Low-Zpolymer sample supports for fixed-target serial femtosecond X-ray crystallography

2015 ◽  
Vol 48 (4) ◽  
pp. 1072-1079 ◽  
Author(s):  
Geoffrey K. Feld ◽  
Michael Heymann ◽  
W. Henry Benner ◽  
Tommaso Pardini ◽  
Ching-Ju Tsai ◽  
...  
Keyword(s):  
Protective Antigen ◽  
Three Dimensional ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Fixed Target ◽  
X Ray ◽  
X Ray Crystallography ◽  
Transmission Electron ◽  
Linac Coherent Light Source ◽  
Efficient Alternative

X-ray free-electron lasers (XFELs) offer a new avenue to the structural probing of complex materials, including biomolecules. Delivery of precious sample to the XFEL beam is a key consideration, as the sample of interest must be serially replaced after each destructive pulse. The fixed-target approach to sample delivery involves depositing samples on a thin-film support and subsequent serial introductionviaa translating stage. Some classes of biological materials, including two-dimensional protein crystals, must be introduced on fixed-target supports, as they require a flat surface to prevent sample wrinkling. A series of wafer and transmission electron microscopy (TEM)-style grid supports constructed of low-Zplastic have been custom-designed and produced. Aluminium TEM grid holders were engineered, capable of delivering up to 20 different conventional or plastic TEM grids using fixed-target stages available at the Linac Coherent Light Source (LCLS). As proof-of-principle, X-ray diffraction has been demonstrated from two-dimensional crystals of bacteriorhodopsin and three-dimensional crystals of anthrax toxin protective antigen mounted on these supports at the LCLS. The benefits and limitations of these low-Zfixed-target supports are discussed; it is the authors' belief that they represent a viable and efficient alternative to previously reported fixed-target supports for conducting diffraction studies with XFELs.

The Role of Three Dimension Computerized Imaging in Hand Surgery

1987 ◽  
Vol 12 (3) ◽  
pp. 349-352
Author(s):  
J. ENGEL ◽  
M. SALAI ◽  
B. YAFFE ◽  
R. TADMOR
Keyword(s):  
Three Dimensional ◽  
Hand Surgery ◽  
New Technique ◽  
Silicone Implants ◽  
Three Dimension ◽  
Two Dimensional ◽  
Radiological Imaging ◽  
Preliminary Results ◽  
Dimensional Picture

Three-dimensional computerized imaging is a new modality of radiological imaging. This new technique transforms the two-dimensional slices of bi-plane CT into a three-dimensional picture by a computer’s monitor adjusted to the system. This system enables the physician to rotate the angle of viewing of the desired region to any desired angle. Moreover, this system can delete certain features of different densities from the picture, such as silicone implants, thus improving visualization. Our preliminary results using this technique are presented. The advantages, pitfalls, and suggested future applications of this new technique in hand surgery are discussed.

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