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3d space

Toufik Sadi, Adnan Mehonic, Luca Montesi, Mark Buckwell, Anthony Kenyon, Asen Asenov
We employ an advanced three-dimensional (3D) electro-thermal simulator to explore the physics and potential of oxide-based resistive random-access memory (RRAM) cells. The physical simulation model has been developed recently, and couples a kinetic Monte Carlo study of electron and ionic transport to the self-heating phenomenon while accounting carefully for the physics of vacancy generation and recombination, and trapping mechanisms. The simulation framework successfully captures resistance switching, including the electroforming, set and reset processes, by modeling the dynamics of conductive filaments in the 3D space...
January 15, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
L Asensio Romero, M Asensio Gómez, A Prats-Galino, J A Juanes Méndez
We present a computer program designed to visualize and interact with three-dimensional models of the main anatomical structures of the female pelvis. They are reconstructed from serial sections of corpse, from the Visible Human project of the Medical Library of the United States and from serial sections of high-resolution magnetic resonance. It is possible to represent these three-dimensional structures in any spatial orientation, together with sectional images of corpse and magnetic resonance imaging, in the three planes of space (axial, coronal and sagittal) that facilitates the anatomical understanding and the identification of the set of visceral structures of this body region...
January 15, 2018: Journal of Medical Systems
Fang Zhao, Dario Cambié, Jeroen Janse, Eric W Wieland, Koen P L Kuijpers, Volker Hessel, Michael G Debije, Timothy Noël
The use of solar energy to power chemical reactions is a long-standing dream of the chemical community. Recently, visible-light-mediated photoredox catalysis has been recognized as the ideal catalytic transformation to convert solar energy into chemical bonds. However, scaling photochemical transformations has been extremely challenging due to Bouguer-Lambert-Beer law. Recently, we have pioneered the development of luminescent solar concentrator photomicroreactors (LSC-PMs), which display an excellent energy efficiency...
January 2, 2018: ACS Sustainable Chemistry & Engineering
Michele Diana, Eric Noll, Andras Legnèr, Seong-Ho Kong, Yu-Yin Liu, Luigi Schiraldi, Francesco Marchegiani, Jordan Bano, Bernard Geny, Anne-Laure Charles, Bernard Dallemagne, Véronique Lindner, Didier Mutter, Pierre Diemunsch, Jacques Marescaux
BACKGROUND: Standard insufflators compensate for intra-abdominal pressure variations with pressure spikes. Our aim was to evaluate the impact of a stable, low-pressure pneumoperitoneum induced by a valve-less insufflator, on working space, hemodynamics, inflammation, and peritoneal physiology, in a model of laparoscopic sigmoid resection. MATERIALS AND METHODS: Twelve pigs (47 ± 3.3 kg) were equipped for invasive hemodynamic monitoring and randomly assigned to Standard (n = 6) vs...
January 12, 2018: Surgical Endoscopy
Junchao Tu, Liyan Zhang
A new solution to the problem of galvanometric laser scanning (GLS) system calibration is presented. Under the machine learning framework, we build a single-hidden layer feedforward neural network (SLFN)to represent the GLS system, which takes the digital control signal at the drives of the GLS system as input and the space vector of the corresponding outgoing laser beam as output. The training data set is obtained with the aid of a moving mechanism and a binocular stereo system. The parameters of the SLFN are efficiently solved in a closed form by using extreme learning machine (ELM)...
January 12, 2018: Sensors
N A Veretenov, S V Fedorov, N N Rosanov
We predict a new class of three-dimensional (3D) topological dissipative optical one-component solitons in homogeneous laser media with fast saturable absorption. Their skeletons formed by vortex lines where the field vanishes are tangles, i.e., N_{c} knotted or unknotted, linked or unlinked closed lines and M unclosed lines that thread all the closed lines and end at the infinitely far soliton periphery. They are generated by embedding two-dimensional laser solitons or their complexes in 3D space after their rotation around an unclosed, infinite vortex line with topological charge M_{0} (N_{c}, M, and M_{0} are integers)...
December 29, 2017: Physical Review Letters
Pietro Maggi, Martina Absinta, Matteo Grammatico, Luisa Vuolo, Giacomo Emmi, Giovanna Carlucci, Gregorio Spagni, Alessandro Barilaro, Anna Maria Repice, Lorenzo Emmi, Domenico Prisco, Vittorio Martinelli, Roberta Scotti, Niloufar Sadeghi, Gaetano Perrotta, Pascal Sati, Bernard Dachy, Daniel S Reich, Massimo Filippi, Luca Massacesi
OBJECTIVES: In multiple sclerosis (MS), MRI is a sensitive tool for detecting white matter lesions, but its diagnostic specificity is still suboptimal; ambiguous cases are frequent in clinical practice. Detection of perivenular lesions in the brain (the "central vein sign") improves the pathological specificity of MS diagnosis, but comprehensive evaluation of this MRI biomarker in MS-mimicking inflammatory and/or autoimmune diseases, such as CNS inflammatory vasculopathies, is missing...
January 12, 2018: Annals of Neurology
Irina Alexandra Paun, Roxana Cristina Popescu, Cosmin Catalin Mustaciosu, Marian Zamfirescu, Bogdan Stefanita Calin, Mona Mihailescu, Maria Dinescu, Andrei Popescu, Diana Georgiana Chioibasu, Mihai Sopronyi, Catalin Luculescu
A major limitation of existing 3D implantable structures for bone tissue engineering is that most of the cells rapidly attach on the outer edges of the structure, restricting the cells penetration into the inner parts and causing the formation of a necrotic core. Furthermore, these structures generally possess a random spatial arrangement and do not preserve the isotropy on the whole volume. Here, we report on the fabrication and testing of an innovative 3D hierarchical, honeycomb-like structure (HS), with reproducible and isotropic arhitecture, that allows "in volume" migration of osteoblasts...
January 12, 2018: Biofabrication
Rachael M Kenney, Matthew W Boyce, Nathan Whitman, Brenden P Kromhout, Matthew R Lockett
Paper-based cultures are an emerging platform for preparing 3D tissue-like structures. Chemical gradients can be imposed upon these cultures, generating microenvironments similar to those found in poorly vascularized tumors. There is increasing evidence that the tumor microenvironment is responsible for promoting drug resistance and increased invasiveness. Acidosis, or the acidification of the extracellular space, is particularly important in promoting these aggressive cancer phenotypes. To better understand how cells respond to acidosis there is a need for 3D culture platforms that not only model relevant disease states, but also contain sensors capable of quantifying the extracellular environment...
January 11, 2018: Analytical Chemistry
Berkin Bilgic, Tae Hyung Kim, Congyu Liao, Mary Kate Manhard, Lawrence L Wald, Justin P Haldar, Kawin Setsompop
PURPOSE: To develop parallel imaging techniques that simultaneously exploit coil sensitivity encoding, image phase prior information, similarities across multiple images, and complementary k-space sampling for highly accelerated data acquisition. METHODS: We introduce joint virtual coil (JVC)-generalized autocalibrating partially parallel acquisitions (GRAPPA) to jointly reconstruct data acquired with different contrast preparations, and show its application in 2D, 3D, and simultaneous multi-slice (SMS) acquisitions...
January 10, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Shuo Wang, Qiyue Zhang, Rui Yang
Among the characters of caenagnathid oviraptorosaurians, the lateral occlusal grooves and ridges on the occlusal surface of the jaw bones often receive special attention. Recent studies demonstrated that ontogenetic edentulism is present in caenagnathids, and therefore the lateral occlusal grooves and ridges are vestigial alveoli and interdental septa, respectively. In the present paper, the dentary structures of caenagnathids were reevaluated based on CT images of Caenagnathiasia sp. IVPP V20377. Several previously unknown features including crateriform vestigial alveoli, the morphology of the dentary interior hollow space, and the paired blind tubes beneath the dentary symphyseal shelf are recognized...
January 10, 2018: Scientific Reports
Mary T Doolin, Kimberly M Stroka
The in vivo microenvironment is critical for providing physico-chemical signaling cues which ultimately regulate human mesenchymal stem cell (hMSC) behavior in clinically-relevant applications. hMSCs experience mechanical confinement of the cell body and nucleus in 3D tissues during homing and in porous tissue engineered scaffolds, yet the effects of this mechanical cue on hMSC migration are not known. Here, we use a microchannel device to systematically examine the effect of confinement on hMSC migration and cytoskeletal organization...
January 6, 2018: Cytoskeleton
Xiang He, Kenneth Wengler, Mark E Schweitzer
PURPOSE: To evaluate the role of true diffusion and flow-related pseudodiffusion in cerebral blood flow (CBF) quantification using arterial spin labeling (ASL) with single-shot or segmented 3D gradient and spin echo (GRASE) readouts. THEORY: The extended phase graph (EPG) algorithm, originally designed to model the effects of T1 /T2 relaxation and true diffusion in MRI acquisitions utilizing multiple refocusing RF pulses, was augmented (aEPG). This augmentation accounted for flow-related pseudodiffusion attenuation of intravascular MRI signal in the k-space domain during 3D-GRASE acquisition, which leads to blur along the partition direction in the image domain...
January 7, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xing Lu, Yajun Ma, Eric Y Chang, Qun He, Adam Searleman, Annette von Drygalski, Jiang Du
PURPOSE: To evaluate the echo dependence of 3D ultrashort echo time (TE) quantitative susceptibility mapping (3D UTE-QSM) and effective transverse relaxation rate ( R2*) measurement in the setting of high concentrations of iron oxide nanoparticles. METHODS: A phantom study with iron concentrations ranging from 2 to 22 mM was performed using a 3D UTE Cones sequence. Simultaneous QSM processing with morphology-enabled dipole inversion (MEDI) and R2* single exponential fitting was conducted offline with the acquired 3D UTE data...
January 4, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Ming-Li Liang, Yun-Xiang Ma, Chun-Li Hu, Fang Kong, Jiang-Gao Mao
Four new compounds of A(VO2F)(SeO3) (A = Sr 1, Ba 2) and Ba(MOF2)(TeO4) (M = Mo 3, W 4) oxyfluorides have been synthesized successfully by hydrothermal reactions. They represent the first examples of alkali-earth selenites or tellurites with a fluorinated d0-TM octahedron. Their crystal structures were determined by single-crystal X-ray diffraction. They exhibit two different types of structures. Compounds 1 and 2 are isostructural and crystallize in the orthorhombic crystal system with the space group of Pbca (no...
January 9, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Christopher P Cheng, Yufei D Zhu, Ga-Young Suh
The study purpose is to optimize modeling parameters, specifically segmentation spacing and centerline extraction, to efficiently construct accurate 3D aortic models. Models are constructed by centerline extraction and orthogonal 2D segmentations. We examine the effect of segmentation interval spacing (2, 1, 0.5, 0.25 cm) and orthogonal segmentation and centerline extraction iteration (one, two, three iterations) for constructing models of Healthy, Tortuous, Aneurysmal, and Dissected human thoracic aortas...
January 9, 2018: Computer Methods in Biomechanics and Biomedical Engineering
Sergio Benvenuti, Simone Giacomelli
We propose a general way to complete supersymmetric theories with operators below the unitarity bound, adding gauge-singlet fields that enforce the decoupling of such operators. This makes it possible to perform all usual computations, and to compactify on a circle. We concentrate on a duality between an N=1 SU(2) gauge theory and the N=2 A_{3} Argyres-Douglas theory, mapping the moduli space and chiral ring of the completed N=1 theory to those of the A_{3} model. We reduce the completed gauge theory to 3D, finding a 3D duality with N=4 supersymmetric QED (SQED) with two flavors...
December 22, 2017: Physical Review Letters
S Vajapeyam, D Brown, P R Johnston, K I Ricci, M W Kieran, H G W Lidov, T Y Poussaint
BACKGROUND AND PURPOSE: Accurate tumor grading is essential for treatment planning of pediatric brain tumors. We hypothesized that multiparametric analyses of a combination of permeability metrics and ADC histogram metrics would differentiate high- and low-grade tumors with high accuracy. MATERIALS AND METHODS: DTI and dynamic contrast-enhanced MR imaging using T1-mapping with flip angles of 2°, 5°, 10°, and 15°, followed by a 0.1-mmol/kg body weight gadolinium-based bolus was performed on all patients in addition to standard MR imaging...
January 4, 2018: AJNR. American Journal of Neuroradiology
Alexander A Berger, Steven Abramowitch, Pamela A Moalli
INTRODUCTION AND HYPOTHESIS: Defining patient characteristics that alter vascular anatomy at the sacrum is critical for avoiding life-threatening bleeding at the time of sacrocolpopexy. We tested the hypothesis that in thinner/older women, the bifurcations of the aorta and inferior vena cava (IVC) are lower relative to S1 resulting in less space accessible for suture/mesh placement, placing this group at increased risk of major vascular injury. METHODS: In a retrospective cross-sectional study, CT scans were used to make 2D measurements and a 3D model of the aorta/IVC, intervertebral disc space, and bony anatomy using segmentation and modeling software...
January 3, 2018: International Urogynecology Journal
Zhengrui Zhang, Xuan Yang, Cong Tan, Wei Guo, Guoliang Chen
BACKGROUND: Cardiac diseases represent the leading cause of sudden death worldwide. During the development of cardiac diseases, the left ventricle (LV) changes obviously in structure and function. LV motion estimation plays an important role for diagnosis and treatment of cardiac diseases. To estimate LV motion accurately for cine magnetic resonance (MR) cardiac images, we develop an algorithm by combining point set matching with surface structure features of myocardium. METHODS: The structure features of myocardial wall are described by estimating the normal directions of points locating on the myocardium contours using an approximation approach...
December 20, 2017: BMC Medical Informatics and Decision Making
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