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High-density 3D mapping

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https://www.readbyqxmd.com/read/28514687/particulate-array-of-well-ordered-hiv-clade-c-env-trimers-elicits-neutralizing-antibodies-that-display-a-unique-v2-cap-approach
#1
Paola Martinez-Murillo, Karen Tran, Javier Guenaga, Gustaf Lindgren, Monika Àdori, Yu Feng, Ganesh E Phad, Néstor Vázquez Bernat, Shridhar Bale, Jidnyasa Ingale, Viktoriya Dubrovskaya, Sijy O'Dell, Lotta Pramanik, Mats Spångberg, Martin Corcoran, Karin Loré, John R Mascola, Richard T Wyatt, Gunilla B Karlsson Hedestam
The development of soluble envelope glycoprotein (Env) mimetics displaying ordered trimeric symmetry has ushered in a new era in HIV-1 vaccination. The recently reported native, flexibly linked (NFL) design allows the generation of native-like trimers from clinical isolates at high yields and homogeneity. As the majority of infections world-wide are of the clade C subtype, we examined responses in non-human primates to well-ordered subtype C 16055 trimers administered in soluble or high-density liposomal formats...
May 16, 2017: Immunity
https://www.readbyqxmd.com/read/28482032/structure-and-conformational-dynamics-of-scaffolded-dna-origami-nanoparticles
#2
Keyao Pan, William P Bricker, Sakul Ratanalert, Mark Bathe
Synthetic DNA is a highly programmable nanoscale material that can be designed to self-assemble into 3D structures that are fully determined by underlying Watson-Crick base pairing. The double crossover (DX) design motif has demonstrated versatility in synthesizing arbitrary DNA nanoparticles on the 5-100 nm scale for diverse applications in biotechnology. Prior computational investigations of these assemblies include all-atom and coarse-grained modeling, but modeling their conformational dynamics remains challenging due to their long relaxation times and associated computational cost...
May 8, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28479513/epicardial-endocardial-breakthrough-during-stable-atrial-macro-reentry-evidence-from-ultra-high-resolution-three-dimensional-mapping-epicardial-endocardial-breakthrough-in-atrial-macro-reentry
#3
Bhupesh Pathik, Geoffrey Lee, Frédéric Sacher, Michel Haïssaguerre, Pierre Jaïs, Grégoire Massoullié, Nicolas Derval, Prashanthan Sanders, Peter Kistler, Jonathan M Kalman
BACKGROUND: Evidence for epicardial-endocardial breakthrough(EEB) is derived from mapping inferences in patients with AF who may also have focal activations. OBJECTIVES: We investigated whether EEB could be discerned during stable right atrial macro-reentry using high-density high-spatial resolution 3D mapping. METHODS: Macro-reentry was diagnosed using 3D mapping and entrainment. Bipolar maps were reviewed for EEB defined as (i)focal endocardial activation with radial spread unaccounted for by an endocardial wavefront and (ii)present with the same timing on every tachycardia cycle...
May 4, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28463257/high-precision-real-time-3d-shape-measurement-using-a-bi-frequency-scheme-and-multi-view-system
#4
Tianyang Tao, Qian Chen, Shijie Feng, Yan Hu, Jian Da, Chao Zuo
High-speed and high-precision 3D shape measurement plays a central role in diverse applications such as automatic online inspection, robotics control, and human-computer interaction. Conventional multi-frame phase-shifting-based fringe projection profilometry techniques face inherent trade-offs between the speed and measurement precision, which are fundamentally limited by the fringe density and extra pattern projections used for de-ambiguity of fringe orders. Increasing the frequency of the projection fringes can obviously improve the measurement precision; however, it creates difficulties in the subsequent phase unwrapping...
May 1, 2017: Applied Optics
https://www.readbyqxmd.com/read/28463188/tumor-cell-load-and-heterogeneity-estimation-from-diffusion-weighted-mri-calibrated-with-histological-data-an-example-from-lung-cancer
#5
Yi Yin, Oliver Sedlaczek, Benedikt Muller, Arne Warth, Margarita Gonzalez-Vallinas, Niels Grabe, Hans-Ulrich Kauczor, Kai Breuhahn, Irene Vignon-Clemental, Dirk Drasdo
Diffusion-weighted magnetic resonance imaging (DWI) is a key non-invasive imaging technique for cancer diagnosis and tumor treatment assessment, reflecting Brownian movement of water molecules in tissues. Since densely packed cells restrict molecule mobility, tumor tissues produce usually higher signal (a.k.a less attenuated signal) on isotropic maps compared to normal tissues. However, no general quantitative relation between DWI data and the cell density has been established. In order to link low-resolution clinical cross-sectional data with high-resolution histological information, we developed an image processing and analysis chain, which was used to study the correlation between the diffusion coefficient (D value) estimated from DWI and tumor cellularity from serial histological slides of a resected non-small cell lung cancer (NSCLC) tumor...
April 27, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28460192/proton-density-fat-fraction-of-rotator-cuff-muscles-is-associated-with-isometric-strength-10-years-after-rotator-cuff-repair-a-quantitative-magnetic-resonance-imaging-study-of-the-shoulder
#6
Dimitrios C Karampinos, Christian Holwein, Stefan Buchmann, Thomas Baum, Stefan Ruschke, Alexandra S Gersing, Reto Sutter, Andreas B Imhoff, Ernst J Rummeny, Pia M Jungmann
BACKGROUND: Quantitative muscle fat-fraction magnetic resonance (MR) imaging techniques correlate with semiquantitative Goutallier scores with failure after rotator cuff (RC) repair. PURPOSE: To investigate the relationship of proton density fat fraction (PDFF) of the RC muscles with semiquantitative MR scores, cartilage T2 relaxation times, and clinical isometric strength measurements in patients 10 years after unilateral RC repair. STUDY DESIGN: Cross-sectional study; Level of evidence, 3...
April 1, 2017: American Journal of Sports Medicine
https://www.readbyqxmd.com/read/28436918/an-integrated-and-highly-sensitive-ultrafast-acoustoelectric-imaging-system-for-biomedical-applications
#7
Beatrice Berthon, Pierre-Marc Dansette, Mickael Tanter, Mathieu Pernot, Jean Provost
PURPOSE: Direct imaging of cardiac electrical activation is crucial to better understand and diagnose diseases linked to arrhythmias. This work presents an Ultrafast Acoustoelectric Imaging (UAI) system for direct and non-invasive ultrafast mapping of propagating current densities. MATERIALS AND METHODS: Acoustoelectric imaging is based on the acoustoelectric effect, the modulation of the medium's electrical impedance by a propagating ultrasonic wave. UAI triggers this effect with plane wave emissions to image current densities...
April 24, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28416035/measuring-the-autocorrelation-function-of-nanoscale-three-dimensional-density-distribution-in-individual-cells-using-scanning-transmission-electron-microscopy-atomic-force-microscopy-and-a-new-deconvolution-algorithm
#8
Yue Li, Di Zhang, Ilker Capoglu, Karl A Hujsak, Dhwanil Damania, Lusik Cherkezyan, Eric Roth, Reiner Bleher, Jinsong S Wu, Hariharan Subramanian, Vinayak P Dravid, Vadim Backman
Essentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass-density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass-density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction...
April 18, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28410679/dual-energy-imaging-method-to-improve-the-image-quality-and-the-accuracy-of-dose-calculation-for-cone-beam-computed-tomography
#9
Kuo Men, Jianrong Dai, Xinyuan Chen, Minghui Li, Ke Zhang, Peng Huang
PURPOSE: To improve the image quality and accuracy of dose calculation for cone-beam computed tomography (CT) images through implementation of a dual-energy cone-beam computed tomography method (DE-CBCT), and evaluate the improvement quantitatively. METHODS: Two sets of CBCT projections were acquired using the X-ray volumetric imaging (XVI) system on a Synergy (Elekta, Stockholm, Sweden) system with 120kV (high) and 70kV (low) X-rays, respectively. Then, the electron density relative to water (relative electron density (RED)) of each voxel was calculated using a projection-based dual-energy decomposition method...
April 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28407062/voltage-gradient-mapping-and-electrophysiologically-guided-cryoablation-in-children-with-avnrt
#10
Fabrizio Drago, Irma Battipaglia, Mario Salvatore Russo, Romolo Remoli, Vincenzo Pazzano, Gino Grifoni, Greta Allegretti, Massimo Stefano Silvetti
Aims: Recently, voltage gradient mapping of Koch's triangle to find low-voltage connections, or 'voltage bridges', corresponding to the anatomic position of the slow pathway, has been introduced as a method to ablate atrioventricular nodal reentry tachycardia (AVNRT) in children. Thus, we aimed to assess the effectiveness of voltage mapping of Koch's triangle, combined with the search for the slow potential signal in 'low-voltage bridges', to guide cryoablation of AVNRT in children. Methods and results: From June 2015 to May 2016, 35 consecutive paediatric patients (mean age 12...
April 12, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28401432/feasibility-assessment-of-a-maldi-fticr-imaging-approach-for-the-3d-reconstruction-of-a-mouse-lung
#11
E Ellen Jones, Cristine Quiason, Stephanie Dale, Sheerin K Shahidi-Latham
Matrix assisted laser desorption ionization imaging mass spectrometry (MALDI IMS) has proven to be a quick, robust, and label-free tool to produce two-dimensional (2D) ion-density maps representing the distribution of a variety of analytes across a tissue section of interest. In addition, three-dimensional (3D) imaging mass spectrometry workflows have been developed that are capable of visualizing these same analytes throughout an entire volume of a tissue rather than a single cross-section. Until recently, the use of Fourier transform ion cyclotron resonance (FTICR) mass spectrometers for 3D volume reconstruction has been impractical due to software limitations, such as inadequate capacity to manipulate the extremely large data files produced during an imaging experiment...
April 11, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28388052/mapping-charge-distribution-in-single-pbs-core-cds-arm-nano-multipod-heterostructures-by-off-axis-electron-holography
#12
Rajesh Chalasani, Alexander Pekin, Alexander Rabkin, Ran E Abutbul, Oswaldo Diéguez, Yaron Kauffmann, Yuval Golan, Amit Kohn
We synthesized PbS core-CdS arm nanomultipod heterostructures (NMHs) that exhibit PbS{111}/CdS{0002} epitaxial relations. The PbS-CdS interface is chemically sharp as determined by aberration corrected transmission electron microscopy (TEM) and compared to density functional theory (DFT) calculations. Ensemble fluorescence measurements show quenching of the optical signal from the CdS arms indicating charge separation due to the heterojunction with PbS. A finite-element three-dimensional (3D) calculation of the Poisson equation shows a type-I heterojunction, which would prevent recombination in the CdS arm after optical excitation...
April 13, 2017: Nano Letters
https://www.readbyqxmd.com/read/28306555/assessment-of-dosimetric-impact-of-system-specific-geometric-distortion-in-an-mri-only-based-radiotherapy-workflow-for-prostate
#13
C Gustafsson, F Nordström, E Persson, J Brynolfsson, L E Olsson
Dosimetric errors in a magnetic resonance imaging (MRI) only radiotherapy workflow may be caused by system specific geometric distortion from MRI. The aim of this study was to evaluate the impact on planned dose distribution and delineated structures for prostate patients, originating from this distortion. A method was developed, in which computer tomography (CT) images were distorted using the MRI distortion field. The displacement map for an optimized MRI treatment planning sequence was measured using a dedicated phantom in a 3 T MRI system...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28282453/the-use-of-a-novel-signal-analysis-to-identify-the-origin-of-idiopathic-right-ventricular-outflow-tract-ventricular-tachycardia-during-sinus-rhythm-simultaneous-amplitude-frequency-electrogram-transformation-mapping
#14
Abigail Louise D Te, Satoshi Higa, Fa-Po Chung, Chin-Yu Lin, Men-Tzung Lo, Che-An Liu, Chen Lin, Yi-Chung Chang, Shih-Lin Chang, Li-Wei Lo, Yu-Feng Hu, Ta-Chuan Tuan, Tze-Fan Chao, Jonan Liao, Yao-Ting Chang, Chung-Hsing Lin, Yuan Hung, Shinya Yamada, Kuo-Li Pan, Yenn-Jiang Lin, Shih-Ann Chen
INTRODUCTION: The signal characteristics of intracardiac bipolar electrograms at the origin of idiopathic RVOT-VT during sinus rhythm remain unclear. OBJECTIVE: The study sought to develop a novel real-time/online technique, simultaneous amplitude frequency electrogram transformation (SAFE-T), to quantify and localize the diseased ventricular substrate in idiopathic RVOT-VT. METHODS: We retrospectively investigated the intracardiac bipolar recordings in 70 consecutive patients (26% male, mean age 42±12 years) who underwent successful radiofrequency catheter ablation of idiopathic RVOT-VT...
2017: PloS One
https://www.readbyqxmd.com/read/28251877/genomic-landscape-of-cpg-rich-elements-in-human
#15
Vladimir N Babenko, Irina V Chadaeva, Yuriy L Orlov
BACKGROUND: The studies on CpG islands (CGI) and Alu elements functions, evolution, and distribution in the genome started since the discovery in nineteen eighties (1981, 1986, correspondingly). Their highly skewed genome wide distribution implies the non-random retrotransposition pattern. Besides CGIs in gene promoters, CGIs clusters were observed in the homeobox gene regions and in the macrosatellites, but the whole picture of their distribution specifics was not grasped. Attempts to identify any causative features upon their (genome wide) distribution, such as the DNA context mediated preferred insertion sites of Alu repeats, have been made to ascribe their clusters location...
February 7, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28211459/gravitational-body-forces-focus-north-american-intraplate-earthquakes
#16
Will Levandowski, Mark Zellman, Rich Briggs
Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the region; subsequent finite-element modelling shows that seismicity focuses in regions of high-gravity-derived deviatoric stress...
February 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/28165334/sensitivity-of-simulated-transcranial-ultrasound-fields-to-acoustic-medium-property-maps
#17
James Robertson, Eleanor Martin, Ben Cox, Bradley E Treeby
High intensity transcranial focused ultrasound is an FDA approved treatment for essential tremor, while low-intensity applications such as neurostimulation and opening the blood brain barrier are under active research. Simulations of transcranial ultrasound propagation are used both for focusing through the skull, and predicting intracranial fields. Maps of the skull acoustic properties are necessary for accurate simulations, and can be derived from medical images using a variety of methods. The skull maps range from segmented, homogeneous models, to fully heterogeneous models derived from medical image intensity...
April 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28048563/we-ab-207b-05-correlation-of-normal-lung-density-changes-with-dose-after-stereotactic-body-radiotherapy-sbrt-for-early-stage-lung-cancer
#18
Q Wu, S Devpura, K Feghali, C Liu, M Ajlouni, B Movsas, I Chetty
PURPOSE: To investigate correlation of normal lung CT density changes with dose accuracy and outcome after SBRT for patients with early stage lung cancer. METHODS: Dose distributions for patients originally planned and treated using a 1-D pencil beam-based (PB-1D) dose algorithm were retrospectively recomputed using algorithms: 3-D pencil beam (PB-3D), and model-based METHODS: AAA, Acuros XB (AXB), and Monte Carlo (MC). Prescription dose was 12 Gy × 4 fractions...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048395/we-fg-206-07-assessing-the-lung-function-of-patients-with-non-small-cell-lung-cancer-using-hyperpolarized-xenon-129-dissolved-phase-mri
#19
K Qing, J Mugler, Q Chen
PURPOSE: Hyperpolarized xenon-129 dissolved-phase MRI is the first imaging technique that allows 3-dimensional regional mapping of ventilation and gas uptake by tissue and blood the in human lung. Multiple outcome measures can be produced from this method. Existing studies in subjects with major lung diseases compared to healthy controls demonstrated high sensitivities of this method to pulmonary physiological factors including ventilation, alveolar tissue density, surface-to-volume ratio, pulmonary perfusion and gas-blood barrier thickness...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048262/su-g-iep1-07-inaccuracy-of-lesion-blood-flow-quantification-related-to-the-proton-density-reference-image-in-arterial-spin-labeling-mri-of-brain-tumors
#20
M Jen, J Johnson, P Hou, H Liu
PURPOSE: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. METHODS: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed...
June 2016: Medical Physics
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