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https://www.readbyqxmd.com/read/28650610/defect-emission-and-optical-gain-in-sicxoy-h-films
#1
Zhenxu Lin, Hongfei Li, Rui Huang, Yi Zhang, Jie Song, Hongliang Li, Yanqing Guo, Chao Song, John Robertson
Luminescent SiCxOy:H films,which are fabricated at different CH4 flow rates using very high-frequency plasma-enhanced chemical vapor deposition technique, exhibit strong photoluminescence (PL) with tuning from near-infrared to orange regions. The PL features an excitation wavelength independent recombination dynamic. The silicon dangling bond (DB) defects identified by electron paramagnetic resonance spectra are found to play a key role in the PL behavior. The first-principles calculation shows that the Si DB defects introduce a mid-gap state in the band gap, which is in good agreement with the PL energy...
June 26, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28650436/monitoring-the-orientation-of-rare-earth-doped-nanorods-for-flow-shear-tomography
#2
Jongwook Kim, Sébastien Michelin, Michiel Hilbers, Lucio Martinelli, Elodie Chaudan, Gabriel Amselem, Etienne Fradet, Jean-Pierre Boilot, Albert M Brouwer, Charles N Baroud, Jacques Peretti, Thierry Gacoin
Rare-earth phosphors exhibit unique luminescence polarization features originating from the anisotropic symmetry of the emitter ion's chemical environment. However, to take advantage of this peculiar property, it is necessary to control and measure the ensemble orientation of the host particles with a high degree of precision. Here, we show a methodology to obtain the photoluminescence polarization of Eu-doped LaPO4 nanorods assembled in an electrically modulated liquid-crystalline phase. We measure Eu(3+) emission spectra for the three main optical configurations (σ, π and α, depending on the direction of observation and the polarization axes) and use them as a reference for the nanorod orientation analysis...
June 19, 2017: Nature Nanotechnology
https://www.readbyqxmd.com/read/28650174/dissolution-processes-at-step-edges-of-calcite-in-water-investigated-by-high-speed-frequency-modulation-atomic-force-microscopy-and-simulation
#3
Kazuki Miyata, John Tracey, Keisuke Miyazawa, Ville Anton Haapasilta, Peter Spijker, Yuta Kawagoe, Adam S Foster, Katsuo Tsukamoto, Takeshi Fukuma
The microscopic understanding of the crystal growth and dissolution processes have been greatly advanced by the direct imaging of nanoscale step flows by atomic force microscopy (AFM), optical interferometry and x-ray microscopy. However, one of the most fundamental events that govern their kinetics, namely, atomistic events at the step edges have not been well understood. In this study, we have developed high-speed frequency modulation AFM (FM-AFM) and enabled true atomic-resolution imaging in liquid at ~1 s/frame, which is ~50 times faster than the conventional FM-AFM...
June 26, 2017: Nano Letters
https://www.readbyqxmd.com/read/28649468/microbial-bioenergetics-of-coral-algal-interactions
#4
Ty N F Roach, Maria L Abieri, Emma E George, Ben Knowles, Douglas S Naliboff, Cameron A Smurthwaite, Linda Wegley Kelly, Andreas F Haas, Forest L Rohwer
Human impacts are causing ecosystem phase shifts from coral- to algal-dominated reef systems on a global scale. As these ecosystems undergo transition, there is an increased incidence of coral-macroalgal interactions. Mounting evidence indicates that the outcome of these interaction events is, in part, governed by microbially mediated dynamics. The allocation of available energy through different trophic levels, including the microbial food web, determines the outcome of these interactions and ultimately shapes the benthic community structure...
2017: PeerJ
https://www.readbyqxmd.com/read/28648437/utility-of-adjunctive-modalities-in-coronary-chronic-total-occlusion-intervention
#5
REVIEW
Hemal Bhatt, Sean Janzer, Jon C George
Coronary chronic total occlusion (CTO) intervention remains one of the most challenging domains in interventional cardiology. Due to the technical challenges involved and potential procedural complications, CTO percutaneous coronary intervention (PCI) attempt and success rates remain less than standard PCI. However, the use of several adjunctive tools such as intravascular ultrasound, optical coherence tomography, rotational atherectomy, orbital atherectomy, excimer laser coronary atherectomy and percutaneous left ventricular assist device may contribute to improved CTO PCI success rates or provide better hemodynamic assessment of CTO lesion (i...
May 2017: Indian Heart Journal
https://www.readbyqxmd.com/read/28647530/measuring-kinetic-rate-constants-of-multiple-component-reactions-with-optical-biosensors
#6
David A Edwards, Ryan M Evans, Wenbin Li
One may measure the kinetic rate constants associated with biochemical reactions using an optical biosensor: an instrument in which ligand molecules are convected through a flow cell over a surface to which receptors are immobilized. If there are multiple reactants, one is faced with the problem of fitting multiple kinetic rate constants to one signal, since data from all of the reacting species is lumped together. Even in the presence of ambiguous data, one may use a series of experiments to accurately determine the rate constants...
June 21, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28644797/spatiotemporal-gmm-for-background-subtraction-with-superpixel-hierarchy
#7
Mingliang Chen, Xing Wei, Qingxiong Yang, Qing Li, Gang Wang, Ming-Hsuan Yang
We propose a background subtraction algorithm using hierarchical superpixel segmentation, spanning trees and optical flow. First, we generate superpixel segmentation trees using a number of Gaussian Mixture Models (GMMs) by treating each GMM as one vertex to construct spanning trees. Next, we use the M-smoother to enhance the spatial consistency on the spanning trees and estimate optical flow to extend the M-smoother to the temporal domain. Experimental results on synthetic and real-world benchmark datasets show that the proposed algorithm performs favorably for background subtraction in videos against the state-of-the-art methods in spite of frequent and sudden changes of pixel values...
June 21, 2017: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/28643045/validation-of-a-mathematical-model-for-laser-induced-thermotherapy-in-liver-tissue
#8
F Hübner, C Leithäuser, B Bazrafshan, N Siedow, T J Vogl
The purpose of the study was to develop a simulation approach for laser-induced thermotherapy (LITT) that is based on mathematical models for radiation transport, heat transport, and tissue damage. The LITT ablation was applied to ex vivo pig liver tissue. Experiments were repeated with different laser powers, i.e., 22-34 W, and flow rates of the cooling water in the applicator system, i.e., 47-92 ml/min. During the procedure, the temperature was measured in the liver sample at different distances to the applicator as well as in the cooling circuit using a fiber optic thermometer...
June 22, 2017: Lasers in Medical Science
https://www.readbyqxmd.com/read/28642616/modulational-instability-of-coupled-ring-waveguides-with-linear-gain-and-nonlinear-loss
#9
Nguyen Viet Hung, Krzysztof Zegadlo, Aliaksandr Ramaniuk, Vladimir V Konotop, Marek Trippenbach
We consider a nanostructure of two coupled ring waveguides with constant linear gain and nonlinear absorption - the system that can be implemented in various settings including polariton condensates, optical waveguides or atomic Bose-Einstein condensates. It is found that, depending on the parameters, this simple configuration allows for observing several complex nonlinear phenomena, which include spontaneous symmetry breaking, modulational instability leading to generation of stable circular flows with various vorticities, stable inhomogeneous states with interesting structure of currents flowing between rings, as well as dynamical regimes having signatures of chaotic behavior...
June 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28642572/disrupted-pursuit-compensation-during-self-motion-perception-in-early-alzheimer-s-disease
#10
Jingru Wang, Xiaojun Guo, Xianbo Zhuang, Tuanzhi Chen, Wei Yan
Our perception of the world is remarkably stable despite of distorted retinal input due to frequent eye movements. It is considered that the brain uses corollary discharge, efference copies of signals sent from motor to visual regions, to compensate for distortions and stabilize visual perception. In this study, we tested whether patients with Alzheimer's disease (AD) have impaired corollary discharge functions as evidenced by reduced compensation during the perception of optic flow that mimics self-motion in the environment...
June 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28636406/protective-effect-of-intravitreal-administration-of-exosomes-derived-from-mesenchymal-stem-cells-on-retinal-ischemia
#11
Elad Moisseiev, Johnathon D Anderson, Sharon Oltjen, Mayank Goswami, Robert J Zawadzki, Jan A Nolta, Susanna S Park
PURPOSE: Exosomes derived from human mesenchymal stem cells (hMSCs) cultured under hypoxic conditions contain proteins and growth factors that promote angiogenesis. This study investigated the effect of intravitreal administration of these exosomes on retinal ischemia using a murine model. METHODS: Oxygen-induced retinopathy (OIR) was induced by exposing one-week-old male C57BL/6J mice to 5 days of 75% hyperoxic conditioning, and returning to room air. After hyperoxic conditioning, the right eye of each mouse was injected intravitreally with 1 µl saline or exosomes derived from hMSCs and compared to control mice of the same age raised in room air without OIR injected intravitreally with saline...
June 21, 2017: Current Eye Research
https://www.readbyqxmd.com/read/28632158/on-the-application-of-image-processing-methods-for-bubble-recognition-to-the-study-of-subcooled-flow-boiling-of-water-in-rectangular-channels
#12
Concepción Paz, Marcos Conde, Jacobo Porteiro, Miguel Concheiro
This work introduces the use of machine vision in the massive bubble recognition process, which supports the validation of boiling models involving bubble dynamics, as well as nucleation frequency, active site density and size of the bubbles. The two algorithms presented are meant to be run employing quite standard images of the bubbling process, recorded in general-purpose boiling facilities. The recognition routines are easily adaptable to other facilities if a minimum number of precautions are taken in the setup and in the treatment of the information...
June 20, 2017: Sensors
https://www.readbyqxmd.com/read/28631244/optical-coherence-tomography-angiography-in-pre-perimetric-open-angle-glaucoma
#13
Gilda Cennamo, Daniela Montorio, Nunzio Velotti, Federica Sparnelli, Michele Reibaldi, Giovanni Cennamo
PURPOSE: To evaluate the diagnostic efficacy of optical coherence tomography (OCT) angiography, in patients with pre-perimetric open-angle glaucoma. METHODS: Thirty-eight consecutive eyes of 26 patients with pre-perimetric open-angle glaucoma and 48 normal eyes of 32 controls were included in this prospective study. We evaluated OCT angiography, spectral-domain OCT and visual fields parameters. Differences between controls and patients and between OCT angiography parameters and traditional glaucoma measurements were evaluated...
June 19, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/28629622/optical-coherence-tomography-compared-with-fractional-flow-reserve-guided-approach-in-acute-coronary-syndromes-a-propensity-matched-analysis
#14
Fabrizio D'Ascenzo, Mario Iannaccone, Ovidio De Filippo, Antonio Maria Leone, Giampaolo Niccoli, Filippo Zilio, Fabrizio Ugo, Enrico Cerrato, Massimo Fineschi, Massimo Mancone, Stefano Rigattieri, Nicolas Amabile, Marco Ferlini, Gennaro Sardella, Alberto Cresti, Umberto Barbero, Pascal Motreff, Francesco Colombo, Salvatore Colangelo, Roberto Garbo, Giuseppe Biondi-Zoccai, Corrado Tamburino, Antonio Montefusco, Pierlugi Omedè, Claudio Moretti, Maurizio D'amico, Geraud Souteyrand, Fiorenzo Gaita, Ugo Limbruno, Andrea Picchi
AIM: To compare in patients with ACS (acute coronary syndromes) a PCI (percutaneous coronary intervention) approach based on FFR (fractional flow reserve) vs. one based on OCT (optical coherence tomography). METHODS AND RESULTS: Consecutive patients admitted for ACS and treated with a PCI approach based on OCT or on FFR (recruited in two different studies) were compared and matched with propensity score analysis. Target Lesion revascularization (TLR) was the primary end point, while major adverse cardiovascular events [MACEs defined as the composite of death from cardiac causes, non-fatal MI, clinically driven target vessel revascularization (TVR), or re-hospitalization due to unstable angina] were the secondary ones...
June 3, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28627046/donor-specific-antibodies-are-associated-with-micro-and-macrovascular-coronary-disease-restrictive-myocardial-damage-and-poor-outcome-in-heart-transplanted-patients
#15
Tor Skibsted Clemmensen, Pernille Koefoed-Nielsen, Lis-Ann Jensen, Steen Hvitfeldt Poulsen, Niels Ramsing Holm, Brian Bridal Løgstrup, Evald Høj Christiansen, Jouke Dijkstra, Kamilla Pernille Bjerre Valen, Hans Eiskjaer
AIMS: We examined the relationship between donor-specific HLA antibody (DSA) presence and graft function, hemodynamics, cardiac allograft vasculopathy (CAV), and major adverse cardiac events (MACE) in stable long-term heart-transplanted (HTx) patients. METHODS: Sera from 79 patients (median 7.5 years after HTx) were analyzed for DSA presence. Graft function was evaluated by echocardiography and right heart catheterization. CAV-burden was determined by coronary angiography, optical coherence tomography (OCT), and coronary flow velocity reserve (CFVR)...
June 19, 2017: Clinical Transplantation
https://www.readbyqxmd.com/read/28626243/characterization-of-an-aerosol-microconcentrator-for-analysis-using-microscale-optical-spectroscopies
#16
Lina Zheng, Pramod Kulkarni, Konstantinos Zavvos, Huayan Liang, M Eileen Birch, Dionysios D Dionysiou
Efficient microconcentration of aerosols to a substrate is essential for effectively coupling the collected particles to microscale optical spectroscopies such as laser-induced or spark microplasma, or micro-Raman or infrared spectroscopies. In this study, we present detailed characterization of a corona-based aerosol microconcentration technique developed previously (Diwakar and Kulkarni, 2012). The method involves two coaxial electrodes separated by a few millimeters, one held at a high electrical potential and the other grounded...
February 2017: Journal of Aerosol Science
https://www.readbyqxmd.com/read/28626148/prevalence-of-thin-cap-fibroatheroma-in-relation-to-the-severity-of-anatomical-and-physiological-stenosis
#17
Eisuke Usui, Taishi Yonetsu, Tadashi Murai, Yoshihisa Kanaji, Junji Matsuda, Masahiro Hoshino, Makoto Araki, Takayuki Niida, Masahiro Hada, Sadamitsu Ichijyo, Rikuta Hamaya, Yoshinori Kanno, Tetsumin Lee, Mitsuaki Isobe, Tsunekazu Kakuta
BACKGROUND: The relationship between the features of morphologically unstable plaque and physiological lesion severity remains elusive. We aimed to investigate this relationship using optical coherence tomography (OCT)-derived high-risk plaque characteristics and fractional flow reserve (FFR) as the degree of anatomical and physiological stenosis severity.Methods and Results:We investigated 286 de novo intermediate and severe coronary lesions in 248 patients who underwent OCT and FFR examinations...
June 16, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28623771/liquid-electrode-plasma-optical-emission-spectrometry-combined-with-solid-phase-preconcentration-for-on-site-analysis-of-lead
#18
Suman Barua, Ismail M M Rahman, Iftakharul Alam, Maho Miyaguchi, Hikaru Sawai, Teruya Maki, Hiroshi Hasegawa
A relatively rapid and precise method is presented for the determination of lead in aqueous matrix. The method consists of analyte quantitation using the liquid electrode plasma-optical emission spectrometry (LEP-OES) coupled with selective separation/preconcentration by solid-phase extraction (SPE). The impact of operating variables on the retention of lead in SPEs such as pH, flow rate of the sample solution; type, volume, flow rate of the eluent; and matrix effects were investigated. Selective SPE-separation/preconcentration minimized the interfering effect due to manganese in solution and limitations in lead-detection in low-concentration samples by LEP-OES...
June 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28623310/one-pot-synthesis-of-geas-ultrafine-particles-from-coal-fly-ash-by-vacuum-dynamic-flash-reduction-and-inert-gas-condensation
#19
Lingen Zhang, Zhenming Xu
Ge-monopnictides (GeAs) plays critical role in high-tech industry, especially in the field of advanced optical devices and infrared. As a secondary material, coal fly ash could be further recycled to retrieve germanium and prepare GeAs material with high added values. Hence, the aim of this paper is to propose a one-pot synthesis that uses vacuum flash reduction and inert-gas consolidation method to prepare GeAs ultrafine particles. Germanium in coal fly ash can be successfully recycled; simultaneously, GeAs ultrafine particles were prepared...
June 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28623262/optofluidic-device-for-the-quantification-of-circulating-tumor-cells-in-breast-cancer
#20
Eric Pedrol, Manuel Garcia-Algar, Jaume Massons, Moritz Nazarenus, Luca Guerrini, Javier Martínez, Airan Rodenas, Ana Fernandez-Carrascal, Magdalena Aguiló, Laura G Estevez, Isabel Calvo, Ana Olano-Daza, Eduardo Garcia-Rico, Francesc Díaz, Ramon A Alvarez-Puebla
Metastatic cancer patients require a continuous monitoring during the sequential treatment cycles to carefully evaluate their disease evolution. Repetition of biopsies is very invasive and not always feasible. Herein, we design and demonstrate a 3D-flow focusing microfluidic device, where all optics are integrated into the chip, for the fluorescence quantification of CTCs in real samples. To test the chip performance, two cell membrane targets, the epithelial cell adhesion molecule, EpCAM, and the receptor tyrosine-protein kinase, HER2, are selected...
June 16, 2017: Scientific Reports
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