keyword
MENU ▼
Read by QxMD icon Read
search

X ray phase contrast

keyword
https://www.readbyqxmd.com/read/29792739/x-ray-phase-contrast-technology-in-breast-imaging-principles-options-and-clinical-application
#1
Seyedamir Tavakoli Taba, Timur E Gureyev, Maram Alakhras, Sarah Lewis, Darren Lockie, Patrick C Brennan
OBJECTIVE: The purpose of this article is to review different x-ray phase-contrast breast imaging techniques and their potential application in clinical settings. CONCLUSION: Phase-contrast imaging depicts not only the absorption contrast but also the refraction contrast of the transmitted x-ray beam. Early data suggest that this new modality may overcome some of the diagnostic limitations associated with current clinically available mammography systems and that it has potential for improving breast cancer detection...
May 24, 2018: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/29789967/amorphous-titania-modified-with-boric-acid-for-selective-capture-of-glycoproteins
#2
Shanxia Jin, Liping Liu, Ping Zhou
Amorphous titania was modified with boric acid, and the resulting material was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction and X-ray photoelectron spectrometry. The new material, in contrast to conventional boronate affinity materials containing boronic acid ligands, bears boric acid groups. It is shown to exhibit high specificity for glycoproteins, and this was applied to design a method for solid phase extraction of glycoproteins as shown for ribonuclease B, horse radish peroxidase and ovalbumin...
May 22, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/29780566/nontrigonal-constraint-enhances-1-2-addition-reactivity-of-phosphazenes
#3
Yi-Chun Lin, James C Gilhula, Alexander T Radosevich
The syntheses and 1,2-addition reactivities of nontrigonal phosphazenes supported by trianionic tricoordinating chelates of the type L3 P 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 Ndipp ( 3 : L3 = N[CHC( t Bu)O]2 3- ; 4 : L3 = N( o -NMeC6 H4 )2 3- ; dipp = 2,6-diisopropylphenyl) are reported...
May 14, 2018: Chemical Science
https://www.readbyqxmd.com/read/29772085/ligand-induced-conformational-changes-in-hsp90-monitored-time-resolved-and-label-free-towards-a-conformational-activity-screening-for-drug-discovery
#4
Jörn Güldenhaupt, Marta Amaral, Carsten Kötting, Djordje Musil, Jonas Schartner, Matthias Frech, Klaus Gerwert
A detailed investigation of protein-ligand interactions is crucial during the early drug discovery process. However, most available techniques lack either structural or temporal resolution. In contrast, ATR-FTIR spectroscopy can monitor protein-ligand interactions label-free with high spatiotemporal resolution. Here we immobilize as example the heat shock protein HSP90 on an ATR-crystal. This protein is an important molecular target for drugs against several diseases including cancer. With our novel approach we investigated a ligand induced secondary structural change...
May 17, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29769600/x-ray-based-virtual-histology-allows-guided-sectioning-of-heavy-ion-stained-murine-lungs-for-histological-analysis
#5
Jonas Albers, M Andrea Markus, Frauke Alves, Christian Dullin
Examination of histological or immunohistochemically stained 2D sections of embedded tissue is one of the most frequently used tools in biomedical research and clinical routine. Since to date, targeted sectioning of specific regions of interest (ROI) in the sample is not possible, we aimed at developing a guided sectioning approach based on x-ray 3D virtual histology for heavy ion stained murine lung samples. For this purpose, we increased the contrast to noise ratio of a standard benchtop microCT by 5-10-fold using free-propagation phase contrast imaging and thus substantially improved image quality...
May 16, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29769595/turbulence-and-cavitation-suppression-by-quaternary-ammonium-salt-additives
#6
Homa Naseri, Kieran Trickett, Nicholas Mitroglou, Ioannis Karathanassis, Phoevos Koukouvinis, Manolis Gavaises, Robert Barbour, Dale Diamond, Sarah E Rogers, Maurizio Santini, Jin Wang
We identify the physical mechanism through which newly developed quaternary ammonium salt (QAS) deposit control additives (DCAs) affect the rheological properties of cavitating turbulent flows, resulting in an increase in the volumetric efficiency of clean injectors fuelled with diesel or biodiesel fuels. Quaternary ammonium surfactants with appropriate counterions can be very effective in reducing the turbulent drag in aqueous solutions, however, less is known about the effect of such surfactants in oil-based solvents or in cavitating flow conditions...
May 16, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29765420/a-feasible-method-of-angiogenesis-assessment-in-gastric-cancer-using-3d-microvessel-density
#7
Lu Zhang, Fei Zheng, Zhigang Peng, Zijing Hu, Zhi Yang
Background: Cancer stem cell (CSC) promotes angiogenesis which plays an important role in tumor occurrence, growth, and metastasis. Accurately, quantifying the tumor vasculature can help understanding CSC characteristics and improve cancer diagnosis, therapy planning, and evaluation. The objective of this study is to present a method for improved angiogenesis assessment. Methods: We proposed a three-dimensional microvessel density (3D MVD) to evaluate tumor angiogenesis and tested it in animal models...
2018: Stem Cells International
https://www.readbyqxmd.com/read/29761644/impact-of-stoichiometry-on-the-structure-of-van-der-waals-layered-gete-sb-2-te-3-superlattices-used-in-interfacial-phase-change-memory-ipcm-devices
#8
Philippe Kowalczyk, Françoise Hippert, Nicolas Bernier, Cristian Mocuta, Chiara Sabbione, Walter Batista-Pessoa, Pierre Noé
Van der Waals layered GeTe/Sb2 Te3 superlattices (SLs) have demonstrated outstanding performances for use in resistive memories in so-called interfacial phase-change memory (iPCM) devices. GeTe/Sb2 Te3 SLs are made by periodically stacking ultrathin GeTe and Sb2 Te3 crystalline layers. The mechanism of the resistance change in iPCM devices is still highly debated. Recent experimental studies on SLs grown by molecular beam epitaxy or pulsed laser deposition indicate that the local structure does not correspond to any of the previously proposed structural models...
May 14, 2018: Small
https://www.readbyqxmd.com/read/29758539/bulk-and-dispersed-aqueous-behaviour-of-an-endogenous-lipid-selachyl-alcohol-effect-of-tween-80-and-pluronic-f127-on-nanostructure
#9
Mohammad Younus, Adrian Hawley, Ben J Boyd, Shakila B Rizwan
Tween 80 has been reported to provide a means of targeting drug nanocarriers to the blood- brain barrier. This study investigated the influence of addition of Tween 80 on the formation of different bulk and dispersed lyotropic liquid crystalline phases in selachyl alcohol-based systems. The effect of increasing concentrations of Tween 80 and Pluronic F127 (as a control) (0-25% w/w relative to SA) on the bulk phase behaviour and dispersions of selachyl alcohol (SA) were investigated using small angle X-ray scattering, dynamic light scattering, and cryogenic transmission electron microscopy...
May 7, 2018: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/29757640/supramolecular-properties-of-a-monocarboxylic-acid-functionalized-texas-sized-molecular-box
#10
Ren-Tsung Wu, Xiaodong Chi, Takehiro Hirao, Vincent M Lynch, Jonathan L Sessler
A new carboxylic acid-functionalized "Texas-sized" molecular box TxSB-CO2H has been prepared by combining two separate build-ing blocks via an iodide-catalyzed macrocyclization reaction. A single crystal X-ray diffraction analysis revealed a paired "clip-like" dimer in the solid state. Concentration-dependent behavior is seen for samples of TxSB-CO2H as prepared, as inferred from 1H NMR spectroscopic studies carried out in DMSO-d6. However, in the presence of excess acid (1% by weight of deuterated trifluo-racetic acid; TFA-d1), little evidence of aggregation is seen in DMSO-d6 except at the highest accessible concentrations...
May 14, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29755746/polymorphism-of-terthio-phene-with-surface-confinement
#11
Roland Resel, Andrew O F Jones, Guillaume Schweicher, Roland Fischer, Nicola Demitri, Yves Henri Geerts
The origin of unknown polymorphic phases within thin films is still not well understood. This work reports on crystals of the molecule terthio-phene which were grown by thermal gradient crystallization using glass-plate substrates. The crystalline domains displayed a plate-like morphology with an extended lateral size of about 100 µm, but a thickness of only a few µm. Specular X-ray diffraction patterns confirmed the presence of a new polymorph of terthio-phene. Crystal structure solution from a single crystal peeled from the film revealed a structure with an extremely large unit-cell volume containing 42 independent molecules...
May 1, 2018: IUCrJ
https://www.readbyqxmd.com/read/29750858/a-mof-with-cooperative-phosphines-that-permits-post-synthetic-installation-of-open-metal-sites
#12
Samuel G Dunning, Gianne Nandra, Adam D Conn, Wenrui Chai, R Eric Sikma, Ji-Sung Lee, Pranaw Kunal, Joseph E Reynolds Iii, Jong-San Chang, Alexander Steiner, Graeme Henkelman, Simon Michael Humphrey
PCM-101 is a new phosphine coordination material comprised of tris(p-carboxylato)triphenylphosphine and secondary pillaring groups coordinated to [M3(OH)]5+ nodes (M = Co, Ni). PCM-101 has a unique topology in which R3P: sites are arranged directly trans- to one another, with a P···P separation distance dictated by the pillars. Post-synthetic coordination of soft metals to the P: sites proceeds at room temperature to provide X-ray quality crystals that permit full structural resolution. Addition of AuCl groups forces a large distortion of the parent framework...
May 11, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29750512/experimental-and-theoretical-structural-investigation-of-aupt-nanoparticles-synthesized-using-a-direct-electrochemical-method
#13
Aliya S Lapp, Zhiyao Duan, Nicholas Marcella, Long Luo, Arda Genc, Jan Ringnalda, Anatoly I Frenkel, Graeme Henkelman, Richard M Crooks
In this report, we examine the structure of bimetallic nanomaterials prepared by an electrochemical approach known as hydride-terminated (HT) electrodeposition. It has been shown previously that this method can lead to deposition of a single Pt monolayer on bulk-phase Au surfaces. Specifically, under appropriate electrochemical conditions and using a solution containing PtCl4 2- , a monolayer of Pt atoms electrodeposits onto bulk-phase Au immediately followed by a monolayer of H atoms. The H atom capping layer prevents deposition of Pt multilayers...
May 11, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29740741/zero-extra-dose-pet-delayed-imaging-with-data-driven-attenuation-correction-estimation
#14
Lifang Pang, Wentao Zhu, Yun Dong, Yang Lv, Hongcheng Shi
PURPOSE: Delayed positron emission tomography (PET) imaging may improve sensitivity and specificity in lesion detection. We proposed a PET data-driven method to estimate the attenuation map (AM) for the delayed scan without an additional x-ray computed tomography (CT). PROCEDURES: An emission-attenuation-scatter joint estimation framework was developed. Several practical issues for clinical datasets were addressed. Particularly, the unknown scatter correction was incorporated in the joint estimation algorithm...
May 8, 2018: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
https://www.readbyqxmd.com/read/29719674/cation-%C3%AF-interactions-in-protein-ligand-binding-theory-and-data-mining-reveal-different-roles-for-lysine-and-arginine
#15
Kiran Kumar, Shin M Woo, Thomas Siu, Wilian A Cortopassi, Fernanda Duarte, Robert S Paton
We have studied the cation-π interactions of neutral aromatic ligands with the cationic amino acid residues arginine, histidine and lysine using ab initio calculations, symmetry adapted perturbation theory (SAPT), and a systematic meta-analysis of all available Protein Data Bank (PDB) X-ray structures. Quantum chemical potential energy surfaces (PES) for these interactions were obtained at the DLPNO-CCSD(T) level of theory and compared against the empirical distribution of 2012 unique protein-ligand cation-π interactions found in X-ray crystal structures...
March 14, 2018: Chemical Science
https://www.readbyqxmd.com/read/29717718/density-and-electron-density-of-aqueous-cryoprotectant-solutions-at-cryogenic-temperatures-for-optimized-cryoprotection-and-diffraction-contrast
#16
Timothy J Tyree, Ritwik Dan, Robert E Thorne
The glass-phase densities at T = 77 K of aqueous solutions of the common cryoprotective agents (CPAs) methanol, ethanol, 2-propanol, glycerol, 2-methyl-2,4-pentanediol (MPD), ethylene glycol, polyethylene glycol 200 and polypropylene glycol 425 were measured as a function of CPA concentration. Individual drops with volumes as small as ∼65 pl were rapidly cooled to achieve the glass phase, and their densities at T = 77 K were determined by cryoflotation. These densities were used to determine the glass-phase electron density of each solution and its volume thermal contraction between room temperature and 77 K...
May 1, 2018: Acta Crystallographica. Section D, Structural Biology
https://www.readbyqxmd.com/read/29717143/in-vivo-dynamic-phase-contrast-x-ray-imaging-using-a-compact-light-source
#17
Regine Gradl, Martin Dierolf, Benedikt Günther, Lorenz Hehn, Winfried Möller, David Kutschke, Lin Yang, Martin Donnelley, Rhiannon Murrie, Alexander Erl, Tobias Stoeger, Bernhard Gleich, Klaus Achterhold, Otmar Schmid, Franz Pfeiffer, Kaye Susannah Morgan
We describe the first dynamic and the first in vivo X-ray imaging studies successfully performed at a laser-undulator-based compact synchrotron light source. The X-ray properties of this source enable time-sequence propagation-based X-ray phase-contrast imaging. We focus here on non-invasive imaging for respiratory treatment development and physiological understanding. In small animals, we capture the regional delivery of respiratory treatment, and two measures of respiratory health that can reveal the effectiveness of a treatment; lung motion and mucociliary clearance...
May 1, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29716036/evaluation-of-phase-retrieval-approaches-in-magnified-x-ray-phase-nano-computerized-tomography-applied-to-bone-tissue
#18
Boliang Yu, Loriane Weber, Alexandra Pacureanu, Max Langer, Cecile Olivier, Peter Cloetens, Françoise Peyrin
X-ray phase contrast imaging offers higher sensitivity compared to conventional X-ray attenuation imaging and can be simply implemented by propagation when using a partially coherent synchrotron beam. We address the phase retrieval in in-line phase nano-CT using multiple propagation distances. We derive a method which extends Paganin's single distance method and compare it to the contrast transfer function (CTF) approach in the case of a homogeneous object. The methods are applied to phase nano-CT data acquired at the voxel size of 30 nm (ID16A, ESRF, Grenoble, France)...
April 30, 2018: Optics Express
https://www.readbyqxmd.com/read/29715972/choosing-sensitivity-to-reduce-x-ray-dose-in-medical-phase-contrast-imaging
#19
Oliver Preusche
In medical X-ray imaging, phase contrast imaging is to measure refraction angles caused by the patient. The X-ray dose for a given image quality depends on the sensitivity of the setup, i.e. on the angular measurement range. Measurement ranges of existing phase contrast setups are either too high or too low for perfectly imaging a human finger in air: There is a gap in available measurement ranges, which prevents a reduction of X-ray dose. To fill the gap, this work proposes a novel variant of a Talbot-Lau interferometer...
April 16, 2018: Optics Express
https://www.readbyqxmd.com/read/29714191/development-of-an-x-ray-imaging-system-to-prevent-scintillator-degradation-for-white-synchrotron-radiation
#20
Tunhe Zhou, Hongchang Wang, Thomas Connolley, Steward Scott, Nick Baker, Kawal Sawhney
The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure...
May 1, 2018: Journal of Synchrotron Radiation
keyword
keyword
66507
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"