Search results for "X-Ray"
showing 10 items of 4234 documents
Mortality of ruptured abdominal aortic aneurysm with selective use of endovascular repair
2009
The aim of this review was to examine the results over a seven-year period of treatment for ruptured abdominal aortic aneurysm (RAAA). From 2002 on, our tertiary referral centre offered both open and endovascular (EVAR) treatment modalities for RAAA. All patients with a proven RAAA who were admitted into our hospital were included. Primary outcome measure was surgical mortality. In total 261 patients were admitted with suspicion of acute AAA. Of these, 175 (67%) had a RAAA, confirmed by computed tomography-scanning or at laparotomy. One hundred and fifty-nine patients (90.9%) were treated, 114 by open repair and 45 by EVAR. Overall mortality of patients treated was 25.2%, with an open repai…
Crystalline microstructure of boehmites studied by multi-peak analysis of powder X-ray diffraction patterns
2017
Nanocrystalline boehmite (gamma-aluminium-oxyhydroxide) is a material of industrial importance, the functionality of which follows from its crystalline microstructure. A procedure for preparing boehmite nanoparticles, comprising the formation of a precipitate by the alkalization of an aqueous solution of aluminium nitrate and subsequent hydrothermal aging, was previously elaborated. The application of an additive (maltitol or tartaric acid) to control the sizes and shapes of crystallites in the produced polycrystalline powder of boehmite was developed. The aim of this work is a study of the effect of the hydrothermal treatment time on nanocrystalline characteristics of boehmite, both in abs…
Structure of Dioxygen Binding Xerogels Incorporating Cyclams Complexed with CuCl2 Salts
2005
X-ray absorption/emission spectroscopies were combined in order to elucidate how hybrid xerogels complexed with CuCl2 could bind reversibly O2. Difference EXAFS analyses at the Cu K-edge revealed the existence of binuclear structures with long Cu...Cu distances, i.e. RCu–Cu ≈ 3.98 A and 3.87 A for the oxygenated and oxygen-free xerogels. In oxygenated xerogels, dioxygen would bridge two Cu atoms in a μ-η1 : η1 peroxo-like conformation. The Cu-O signal found at short distance (RCu−O1 = 1.85 ± 0.01 A) is fully consistent with 40% of O2 molecules being chemisorbed per Cu site. In oxygen-free xerogels, Cl K-edge EXAFS revealed the presence of CuI sites with short Cl-Cu bond lengths (RCl−Cu = 2.…
High-pressure x-ray absorption study of GaTe including polarization
2000
The evolution of the local structure in GaTe under pressure is studied by x-ray absorption spectroscopy experiments at the Ga K-edge (10.368 keV) on oriented single crystals. Taking advantage of the linearly polarized character of synchrotron radiation, the pressure evolution of both the Ga-Te and the in-plane Ga-Ga bond lengths could be determined, in spite of the small amplitude of the latter. Our measurements show that both distances are much less compressible than what could be inferred from the bulk compressibility, which evidences a strong variation of Ga-Ga-Te and Te-Ga-Te angles under pressure. The Te-Te intralayer distance perpendicular to the layers is observed to increase with in…
Preparation, crystal structure at 298 and 90 K and phase transition in (C2H5NH3)2 [SbBr5] studied by the single crystal X-ray diffraction method
2004
The reaction of antimony(III) oxide with ethylamine, in molar ratios from 1:1 to 1:10, in concentrated hydrobromic acid leads to the formation of one product - bis(ethylammonium) pentabromoantimonate( III). The structure of (C2H5NH3)2[SbBr5] was determined at 298 and 90 K, below and above the phase transition that occurs at about 158.5 K. The orthorhombic system was found in both phases, space groups Cmca and Pbca at 298 and 90 K, respectively. At both temperatures the structure consists of [SbBr6]3− octahedra connected via cis bromine atoms forming one-dimensional zig-zag [{SbBr5}2−]n chains. The ethylammonium cations fill the space between polyanionic chains. The organic and inorganic sub…
Computed tomography bone density variations in oncological patients undergoing antiresorptive medication
2021
The purpose of this study was to compare jaw and cervical vertebrae bone density in computed tomography (CT) analyses of oncological patients undergoing antiresorptive medication with control patients, aiming to find information that may assist the radiologist and clinician in predicting risks and monitoring osteonecrosis in the jaw. Thirty-one patients treated with zoledronic acid and 37 control were included in the study. Two areas in regions of interest were chosen and standardized, one in the lower portion of the mandible and another in the axial cervical vertebra (C2) of patients undergoing antiresorptive drug treatment (experimental group) and the control group. Density analysis was p…
Ultrasound velocity and cortical bone characteristics in vivo.
2001
Axial transmission of ultrasound along cortical bone may reflect a combination of material and structural properties of long bone cortices. The goal of this study was to determine the association of speed of sound (SOS) with cortical density (CoD), cortical wall thickness (CWT), and total cortical area (CoA). Quantitative ultrasound (QUS) and peripheral quantitative computed tomography (pQCT) were used to measure the above variables in the distal third of radius and the midshaft of tibia in 51 postmenopausal women aged 62 to 71 years. Univariate regression analysis showed that the site-specific CoD accounted for 34% of the variability in the radial SOS and 29% of that in the tibial SOS (p0.…
Periacetabular Cortical and Cancellous Bone Mineral Density Loss After Press-Fit Cup Fixation
2012
The impact of total hip arthroplasty on strain adaptive bone remodeling has been extensively analyzed by dual-energy x-ray absorptiometry. In this study, we present a prospective computed tomography-assisted study of periacetabular cortical and cancellous bone mineral density (in milligrams of calcium hydroxyapatite [CaHA] per milliliter, or mgCaHA/mL) changes 10 days and 1, 3, and 7 years after press-fit cup implantation for 38 hips in vivo. Cancellous bone mineral density decreased by O -63% ventral and O -85% dorsal to the cup; cortical bone mineral density, by O -22% ventral and O -18% dorsal to the cup. The presented periacetabular strain adaptive bone mineral density data are the most…
Resolving Binding Events on the Multifunctional Human Serum Albumin
2020
Abstract Physiological processes rely on initial recognition events between cellular components and other molecules or modalities. Biomolecules can have multiple sites or mode of interaction with other molecular entities, so that a resolution of the individual binding events in terms of spatial localization as well as association and dissociation kinetics is required for a meaningful description. Here we describe a trichromatic fluorescent binding‐ and displacement assay for simultaneous monitoring of three individual binding sites in the important transporter and binding protein human serum albumin. Independent investigations of binding events by X‐ray crystallography and time‐resolved dyn…
Synthesis and coordinating ability of an anionic cobaltabisdicarbollide ligand geometrically analogous to BINAP.
2004
The anionic chelating ligand [1,1'-(PPh 2 ) 2 -3,3'-Co(1,2-C 2 B 9 H 1 0 ) 2 ] - has been synthesized from [3,3'-Co(1,2-C 2 B 4 H 1 1 ) 2 ] - in very good yield in a one-pot process with an easy work-up procedure. The coordinating ability of this ligand has been studied with Group 11 metal ions (Ag, Au) and with transition-metal ions (Pd, Rh). The two dicarbollide halves of the [1,1'-(PPh 2 ) 2 -3,3'-Co(1,2-C 2 B 9 H 1 0 ) 2 ] - ligand can swing about one axis in a manner analogous to the constituent parts of BINAP and ferrocenyl phosphine derivatives. All these ligands function as hinges, with the most important property in relation to the coordination requirements of the metal being the P…