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https://www.readbyqxmd.com/read/27921121/a%C3%A2-4d-ultrasound-real-time-tracking-system-for-external-beam-radiotherapy-of-upper-abdominal-lesions-under-breath-hold
#1
Dwi Seno Kuncoro Sihono, Lena Vogel, Christel Weiß, Johannes Thölking, Frederik Wenz, Frank Lohr, Judit Boda-Heggemann, Hansjörg Wertz
BACKGROUND AND PURPOSE: To evaluate a novel four-dimensional (4D) ultrasound (US) tracking system for external beam radiotherapy of upper abdominal lesions under computer-controlled deep-inspiration breath-hold (DIBH). MATERIALS AND METHODS: The tracking accuracy of the research 4D US system was evaluated using two motion phantoms programmed with sinusoidal and breathing patterns to simulate free breathing and DIBH. Clinical performance was evaluated with five healthy volunteers...
December 5, 2016: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/27921118/can-different-occlusal-positions-instantaneously-impact-spine-and-body-posture-a-pilot-study-using-rasterstereography-for-a-three-dimensional-evaluation
#2
Karoline März, Werner Adler, Ragai-Edward Matta, Linda Wolf, Manfred Wichmann, Bastian Bergauer
PURPOSE: Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions...
December 5, 2016: Journal of Orofacial Orthopedics, Fortschritte der Kieferorthopädie
https://www.readbyqxmd.com/read/27918636/4d-printing-of-shape-memory-based-personalized-endoluminal-medical-devices
#3
Matt Zarek, Nicola Mansour, Shir Shapira, Daniel Cohn
The convergence of additive manufacturing and shape-morphing materials is promising for the advancement of personalized medical devices. The capability to transform 3D objects from one shape to another, right off the print bed, is known as 4D printing. Shape memory thermosets can be tailored to have a range of thermomechanical properties favorable to medical devices, but processing them is a challenge because they are insoluble and do not flow at any temperature. This study presents here a strategy to capitalize on a series of medical imaging modalities to construct a printable shape memory endoluminal device, exemplified by a tracheal stent...
December 5, 2016: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/27917312/a-4d-ct-digital-phantom-of-an-individual-human-brain-for-perfusion-analysis
#4
Rashindra Manniesing, Christoph Brune, Bram van Ginneken, Mathias Prokop
Brain perfusion is of key importance to assess brain function. Modern CT scanners can acquire perfusion maps of the cerebral parenchyma in vivo at submillimeter resolution. These perfusion maps give insights into the hemodynamics of the cerebral parenchyma and are critical for example for treatment decisions in acute stroke. However, the relations between acquisition parameters, tissue attenuation curves, and perfusion values are still poorly understood and cannot be unraveled by studies involving humans because of ethical concerns...
2016: PeerJ
https://www.readbyqxmd.com/read/27912840/the-semaphorins-and-their-receptors-as-modulators-of-tumor-progression
#5
Gera Neufeld, Yelena Mumblat, Tanya Smolkin, Shira Toledano, Inbal Nir-Zvi, Keren Ziv, Ofra Kessler
The semaphorins were initially characterized as repulsive axon guidance factors. However, they are currently also recognized as important regulators of diverse biological processes which include regulation of immune responses, angiogenesis, organogenesis, and a variety of additional physiological and developmental functions. The semaphorin family consists of more than 20 genes divided into seven subfamilies, all of which contain the sema domain signature. They usually transduce signals by activation of receptors belonging to the plexin family, either directly, or indirectly following the binding of some semaphorins to receptors of the neuropilin family which subsequently associate with plexins...
November 2016: Drug Resistance Updates: Reviews and Commentaries in Antimicrobial and Anticancer Chemotherapy
https://www.readbyqxmd.com/read/27910824/accelerated-high-resolution-photoacoustic-tomography-via-compressed-sensing
#6
Simon Arridge, Paul Beard, Marta Betcke, Ben Cox, Nam Huynh, Felix Lucka, Olumide Ogunlade, Edward Zhang
Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in living tissue (4D PAT). A particular example is the planar Fabry-Pérot (FP) photoacoustic scanner, which yields high-resolution 3D images but takes several minutes to sequentially map the incident photoacoustic field on the 2D sensor plane, point-by-point. However, as the spatio-temporal complexity of many absorbing tissue structures is rather low, the data recorded in such a conventional, regularly sampled fashion is often highly redundant...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27910820/4d-bioprinting-the-next-generation-technology-for-biofabrication-enabled-by-stimuli-responsive-materials
#7
Yi-Chen Li, Yu Shrike Zhang, Ali Akpek, Su Ryon Shin, Ali Khademhosseini
Four-dimensional (4D) bioprinting, encompassing a wide range of disciplines including bioengineering, materials science, chemistry, and computer sciences, is emerging as the next-generation biofabrication technology. By utilizing stimuli-responsive materials and advanced three-dimensional (3D) bioprinting strategies, 4D bioprinting aims to create dynamic 3D patterned biological structures that can transform their shapes or behavior under various stimuli. In this review, we highlight the potential use of various stimuli-responsive materials for 4D printing and their extension into biofabrication...
December 2, 2016: Biofabrication
https://www.readbyqxmd.com/read/27910396/four-dimensional-4d-tracking-of-high-temperature-microparticles
#8
Zhehui Wang, Q Liu, W Waganaar, J Fontanese, D James, T Munsat
High-speed tracking of hot and molten microparticles in motion provides rich information about burning plasmas in magnetic fusion. An exploding-wire apparatus is used to produce moving high-temperature metallic microparticles and to develop four-dimensional (4D) or time-resolved 3D particle tracking techniques. The pinhole camera model and algorithms developed for computer vision are used for scene calibration and 4D reconstructions. 3D positions and velocities are then derived for different microparticles...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27909799/thyroid-gland-visualization-with-3d-4d-ultrasound-integrated-hands-on-imaging-in-anatomical-dissection-laboratory
#9
John L Carter, Ankura Patel, Gabriel Hocum, Brion Benninger
PURPOSE: In teaching anatomy, clinical imaging has been utilized to supplement the traditional dissection laboratory promoting education through visualization of spatial relationships of anatomical structures. Viewing the thyroid gland using 3D/4D ultrasound can be valuable to physicians as well as students learning anatomy. The objective of this study was to investigate the perceptions of first-year medical students regarding the integration of 3D/4D ultrasound visualization of spatial anatomy during anatomical education...
December 1, 2016: Surgical and Radiologic Anatomy: SRA
https://www.readbyqxmd.com/read/27908835/modulation-of-signaling-through-gpcr-camp-pka-pathways-by-pde4-depends-on-stimulus-intensity-possible-implications-for-the-pathogenesis-of-acrodysostosis-without-hormone-resistance
#10
Emmanuelle Motte, Catherine Le Stunff, Claire Briet, Nicolas Dumaz, Caroline Silve
In acrodysostosis without hormone resistance, a disease caused by phosphodiesterase (PDE)-4D mutations, increased PDE activity leads to bone developmental defects but with normal renal responses to PTH. To identify potential mechanisms for these disparate responses, we compared the effect of PDE activity on hormone signaling through the GPCR-Gsα-cAMP-PKA pathway in cells from two lineages, HEK-293 cells stably overexpressing PTH1R (HEKpthr) and human dermal fibroblasts, including studies evaluating cAMP levels using an Epac-based BRET-sensor for cAMP (CAMYEL)...
November 28, 2016: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/27908178/a-probability-based-multi-cycle-sorting-method-for-4d-mri-a-simulation-study
#11
Xiao Liang, Fang-Fang Yin, Yilin Liu, Jing Cai
PURPOSE: To develop a novel probability-based sorting method capable of generating multiple breathing cycles of 4D-MRI images and to evaluate performance of this new method by comparing with conventional phase-based methods in terms of image quality and tumor motion measurement. METHODS: Based on previous findings that breathing motion probability density function (PDF) of a single breathing cycle is dramatically different from true stabilized PDF that resulted from many breathing cycles, it is expected that a probability-based sorting method capable of generating multiple breathing cycles of 4D images may capture breathing variation information missing from conventional single-cycle sorting methods...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27908174/respiratory-motion-compensation-for-simultaneous-pet-mr-based-on-highly-undersampled-mr-data
#12
Christopher M Rank, Thorsten Heußer, Andreas Wetscherek, Martin T Freitag, Oliver Sedlaczek, Heinz-Peter Schlemmer, Marc Kachelrieß
PURPOSE: Positron emission tomography (PET) of the thorax region is impaired by respiratory patient motion. To account for motion, the authors propose a new method for PET/magnetic resonance (MR) respiratory motion compensation (MoCo), which uses highly undersampled MR data with acquisition times as short as 1 min/bed. METHODS: The proposed PET/MR MoCo method (4D jMoCo PET) uses radial MR data to estimate the respiratory patient motion employing MR joint motion estimation and image reconstruction with temporal median filtering...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27907235/the-2d-4d-ratio-as-a-predictor-of-the-risk-of-recidivism-after-court-mandated-intervention-program-for-intimate-partner-violence-perpetrators
#13
Angel Romero-Martínez, Marisol Lila, Luis Moya-Albiol
Differences in aggressive behavior could be partially explained by differential prenatal exposure to testosterone (T). A peripheral marker of prenatal T exposure is the 2D:4D ratio, which has shown a negative correlation with self-reported aggression in violent men. This study tested the direct association of the 2D:4D ratio with anger expression and the risk of recidivism in intimate partner violence (IPV) perpetrators after psychotherapeutic intervention program. The sample consisted of IPV perpetrators, whose 2D:4D ratio was measured before the intervention...
December 1, 2016: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/27906372/depth-based-refocusing-for-reducing-directional-aliasing-artifacts
#14
Ensun Lee, Seohee Yang, Miseon Han, Jeongtae Kim
We investigate a depth-based refocusing method using four-dimensional (4D) light field data, which can reduce directional aliasing artifacts in a refocused image. Unlike conventional filtering-based methods, the proposed method estimates the amount of aliasing artifacts using the disparity information between two neighboring views. It then applies an exact smoothing operation to the refocused image in order to remove the aliasing artifacts. By doing that, the proposed method is able to generate a smoothly blurred image in the out-of-focus region and a sharp image in the focused region...
November 28, 2016: Optics Express
https://www.readbyqxmd.com/read/27901146/comparative-experimental-and-theoretical-study-of-the-rotational-excitation-of-co-by-collision-with-ortho-and-para-d2-molecules
#15
T Stoecklin, A Faure, P Jankowski, S Chefdeville, A Bergeat, C Naulin, S B Morales, M Costes
A joint crossed beam and quantum mechanical investigation of the rotationally inelastic collisions of CO with ortho- and para-D2 molecules is reported. A new 4D potential energy surface (PES) averaged over the ground vibrational states of D2 and CO is used to calculate the rovibrational bound states of the ortho-D2-CO complexes. Close coupling calculations are then performed in the rigid rotor approximation for ortho- and para-D2 colliding with CO for the experimentally investigated transition of CO (j = 0 → 1) and for collision energies ranging from 0...
November 30, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27901091/kitaev-exchange-and-field-induced-quantum-spin-liquid-states-in-honeycomb-%C3%AE-rucl3
#16
Ravi Yadav, Nikolay A Bogdanov, Vamshi M Katukuri, Satoshi Nishimoto, Jeroen van den Brink, Liviu Hozoi
Large anisotropic exchange in 5d and 4d oxides and halides open the door to new types of magnetic ground states and excitations, inconceivable a decade ago. A prominent case is the Kitaev spin liquid, host of remarkable properties such as protection of quantum information and the emergence of Majorana fermions. Here we discuss the promise for spin-liquid behavior in the 4d(5) honeycomb halide α-RuCl3. From advanced electronic-structure calculations, we find that the Kitaev interaction is ferromagnetic, as in 5d(5) iridium honeycomb oxides, and indeed defines the largest superexchange energy scale...
November 30, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27898754/genome-wide-association-mapping-of-fusarium-head-blight-resistance-in-wheat-using-genotyping-by-sequencing
#17
Marcio P Arruda, Patrick Brown, Gina Brown-Guedira, Allison M Krill, Carrie Thurber, Keith R Merrill, Bradley J Foresman, Frederic L Kolb
Fusarium head blight (FHB) is one of the most important wheat ( L.) diseases worldwide, and host resistance displays complex genetic control. A genome-wide association study (GWAS) was performed on 273 winter wheat breeding lines from the midwestern and eastern regions of the United States to identify chromosomal regions associated with FHB resistance. Genotyping-by-sequencing (GBS) was used to identify 19,992 single-nucleotide polymorphisms (SNPs) covering all 21 wheat chromosomes. Marker-trait associations were performed with different statistical models, the most appropriate being a compressed mixed linear model (cMLM) controlling for relatedness and population structure...
March 2016: Plant Genome
https://www.readbyqxmd.com/read/27895995/photoreceptor-disc-shedding-in-the-living-human-eye
#18
Omer P Kocaoglu, Zhuolin Liu, Furu Zhang, Kazuhiro Kurokawa, Ravi S Jonnal, Donald T Miller
Cone photoreceptors undergo a daily cycle of renewal and shedding of membranous discs in their outer segments (OS), the portion responsible for light capture. These physiological processes are fundamental to maintaining photoreceptor health, and their dysfunction is associated with numerous retinal diseases. While both processes have been extensively studied in animal models and postmortem eyes, little is known about them in the living eye, in particular human. In this study, we report discovery of the optical signature associated with disc shedding using a method based on adaptive optics optical coherence tomography (AO-OCT) in conjunction with post-processing methods to track and monitor individual cone cells in 4D...
November 1, 2016: Biomedical Optics Express
https://www.readbyqxmd.com/read/27894675/the-manifestation-of-vortical-and-secondary-flow-in-the-cerebral-venous-outflow-tract-an-in-vivo-mr-velocimetry-study
#19
Sarah Kefayati, Matthew Amans, Farshid Faraji, Megan Ballweber, Evan Kao, Sinyeob Ahn, Karl Meisel, Van Halbach, David Saloner
Aberrations in flow in the cerebral venous outflow tract (CVOT) have been implicated as the cause of several pathologic conditions including idiopathic intracranial hypertension (IIH), multiple sclerosis (MS), and pulsatile tinnitus (PT). The advent of 4D flow magnetic resonance imaging (4D-flow MRI) has recently allowed researchers to evaluate blood flow patterns in the arterial structures with great success. We utilized similar imaging techniques and found several distinct flow characteristics in the CVOT of subjects with and without lumenal irregularities...
November 15, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/27894001/multiresolution-extended-free-form-deformations-xffd-for-non-rigid-registration-with-discontinuous-transforms
#20
Rui Hua, Jose M Pozo, Zeike A Taylor, Alejandro F Frangi
Image registration is an essential technique to obtain point correspondences between anatomical structures from different images. Conventional non-rigid registration methods assume a continuous and smooth deformation field throughout the image. However, the deformation field at the interface of different organs is not necessarily continuous, since the organs may slide over or separate from each other. Therefore, imposing continuity and smoothness ubiquitously would lead to artifacts and increased errors near the discontinuity interface...
November 9, 2016: Medical Image Analysis
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