Search results for "X-Ray"
showing 10 items of 4234 documents
Structure‐Activity Relationships of Benzamides and Isoindolines Designed as SARS‐CoV Protease Inhibitors Effective against SARS‐CoV‐2
2020
Abstract Inhibition of coronavirus (CoV)‐encoded papain‐like cysteine proteases (PLpro) represents an attractive strategy to treat infections by these important human pathogens. Herein we report on structure‐activity relationships (SAR) of the noncovalent active‐site directed inhibitor (R)‐5‐amino‐2‐methyl‐N‐(1‐(naphthalen‐1‐yl)ethyl) benzamide (2 b), which is known to bind into the S3 and S4 pockets of the SARS‐CoV PLpro. Moreover, we report the discovery of isoindolines as a new class of potent PLpro inhibitors. The studies also provide a deeper understanding of the binding modes of this inhibitor class. Importantly, the inhibitors were also confirmed to inhibit SARS‐CoV‐2 replication in …
Determination of optimal fluoroscopic angulations for aorto-coronary ostial interventions from coronary computed tomography angiography.
2020
Abstract Background An optimal aorto-coronary angiographic projection, characterized by an orthogonal visualization of the proximal coronary artery, is crucial for interventional success. We determined the distribution of optimal C-arm positions and assessed their feasibility by invasive coronary angiography. Methods Orthogonal aorto-coronary ostial angulations were determined in 310 CT data sets. In 100 patients undergoing subsequent invasive angiography, we assessed if the CT-predicted angulations were achievable by the C-arm system. If the predicted projection was not achievable due to mechanical constraints of the C-arm system, the most close, achievable angulation was determined. Patie…
Toward morphological thoracic EIT: major signal sources correspond to respective organ locations in CT.
2012
Lung and cardiovascular monitoring applications of electrical impedance tomography (EIT) require localization of relevant functional structures or organs of interest within the reconstructed images. We describe an algorithm for automatic detection of heart and lung regions in a time series of EIT images. Using EIT reconstruction based on anatomical models, candidate regions are identified in the frequency domain and image-based classification techniques applied. The algorithm was validated on a set of simultaneously recorded EIT and CT data in pigs. In all cases, identified regions in EIT images corresponded to those manually segmented in the matched CT image. Results demonstrate the abilit…
Automatic segmentation of the spine by means of a probabilistic atlas with a special focus on ribs suppression
2017
[EN] Purpose: The development of automatic and reliable algorithms for the detection and segmentation of the vertebrae are of great importance prior to any diagnostic task. However, an important problem found to accurately segment the vertebrae is the presence of the ribs in the thoracic region. To overcome this problem, a probabilistic atlas of the spine has been developed dealing with the proximity of other structures, with a special focus on ribs suppression. Methods: The data sets used consist of Computed Tomography images corresponding to 21 patients suffering from spinal metastases. Two methods have been combined to obtain the final result: firstly, an initial segmentation is performe…
The Athena X-ray Integral Field Unit (X-IFU)
2016
Event: SPIE Astronomical Telescopes + Instrumentation, 2016, Edinburgh, United Kingdom.
Peculiarities of the local structure in new medium- and high-entropy, low-symmetry tungstates
2022
G. Bakradze acknowledges financial support provided by the Latvian Council of Science for project no. 1.1.1.2/VIAA/3/19/444 (agreement no. 1.1.1.2/16/I/001) realized at the Institute of Solid State Physics, University of Latvia. The Institute of Solid State Physics, University of Latvia, as a centre of excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART2.
Chemical-state analyses of Ni, Zn, and W ions in NiWO$_4$-ZnWO$_4$ solid solutions by X-ray photoelectron spectroscopy
2022
The chemical states of Ni, Zn, and W in microcrystalline NiWO$_4$-ZnWO$_4$ solid solutions were studied by X-ray photoelectron spectroscopy. The recorded spectra of the Ni 2p, Zn 2p, and W 4f photoelectron lines and Ni L$_2$M$_{23}$M$_{45}$, Zn L$_3$M$_{45}$M$_{45}$, and W N$_4$N$_{67}$N$_{7}$ Auger-transition lines show pronounced changes with increasing Zn concentration. The positions of the resolved photoelectron and Auger-transition lines were combined to construct so-called chemical-state plots (Wagner or Auger-parameter plots) for metal ions in solid solutions. With increasing Zn concentration, the Auger parameter increases for Ni and decreases for W, thus evidencing a lowering and an…
Electronic properties of Co2FeSi investigated by X-ray magnetic linear dichroism
2014
We present experimental XMLD spectra measured on epitaxial (001)-oriented thin Co$_{2}$FeSi films, which are rich in features and depend sensitively on the degree of atomic order and interdiffusion from capping layers. Al- and Cr-capped films with different degrees of atomic order were prepared by DC magnetron sputtering by varying the deposition temperatures. The local structural properties of the film samples were additionally investigated by nuclear magnetic resonance (NMR) measurements. The XMLD spectra of the different samples show clear and uniform trends at the $L_{3,2}$ edges. The Al-capped samples show similar behavior as previous measured XMLD spectra of Co$_2$FeSi$_{0.6}$Al$_{0.4…
High-pressure x-ray diffraction study of SrMoO4 and pressure-induced structural changes
2007
SrMoO4 was studied under compression up to 25 GPa by angle-dispersive x-ray diffraction. A phase transition was observed from the scheelite-structured ambient phase to a monoclinic fergusonite phase at 12.2(9) GPa with cell parameters a = 5.265(9) A, b = 11.191(9) A, c = 5.195 (5) A, and beta = 90.9, Z = 4 at 13.1 GPa. There is no significant volume collapse at the phase transition. No additional phase transitions were observed and on release of pressure the initial phase is recovered, implying that the observed structural modifications are reversible. The reported transition appeared to be a ferroelastic second-order transformation producing a structure that is a monoclinic distortion of t…
High-pressure structural phase transitions in CuWO4
2010
We study the effects of pressure on the structural, vibrational, and magnetic behavior of cuproscheelite. We performed powder x-ray diffraction and Raman spectroscopy experiments up to 27 GPa as well as ab initio total-energy and lattice-dynamics calculations. Experiments provide evidence that a structural phase transition takes place at 10 GPa from the low-pressure triclinic phase (P-1) to a monoclinic wolframite-type structure (P2/c). Calculations confirmed this finding and indicate that the phase transformation involves a change in the magnetic order. In addition, the equation of state for the triclinic phase is determined: V0 = 132.8(2) A3, B0 = 139 (6) GPa and = 4. Furthermore, experim…