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https://www.readbyqxmd.com/read/29351692/homonymous-hemianopia-in-children-and-adolescents-an-mri-study
#1
Manja Haaga, Susanne Trauzettel-Klosinski, Anna Krumm, Stephan Küster, Iliya Ivanov, Angelika Cordey, Claudia Gehrlich, Martin Staudt
AIM:  Diagnosing homonymous hemianopia (HH) in children can be difficult due to inability to comply with perimetry. Therefore, HH can often only be suspected by magnetic resonance imaging (MRI) showing lesions to the retrochiasmatic visual pathways. The aim of our retrospective observational cross-sectional study was to improve the radiologic detection of HH. METHODS:  MRIs of 21 subjects (5-17 years old) with ophthalmologically confirmed HH (14 complete, 7 incomplete hemianopias) were analyzed...
January 19, 2018: Neuropediatrics
https://www.readbyqxmd.com/read/29351691/out-of-field-doses-in-children-treated-for-large-arteriovenous-malformations-using-hypofractionated-gamma-knife-radiosurgery-and-intensity-modulated-radiation-therapy
#2
Marijke De Saint-Hubert, Marija Majer, Hrvoje Hršak, Zdravko Heinrich, Željka Kneževic, Saveta Miljanic, Paulina Porwol, Liliana Stolarczyk, Filip Vanhavere, Roger M Harrison
The purpose of this study was to measure out-of-field organ doses in two anthropomorphic child phantoms for the treatment of large brain arteriovenous malformations (AVMs) using hypofractionated gamma knife (GK) radiosurgery and to compare these with an alternative treatment using intensity-modulated radiation therapy (IMRT). Target volume was identical in size and shape in all cases. Radiophotoluminescent (RPL), thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters were used for out-of-field dosimetry during GK treatment and a good agreement within 1-2% between results was shown...
January 17, 2018: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/29351398/visceral-hypersensitivity-induced-by-optogenetic-activation-of-the-amygdala-in-conscious-rats
#3
Anthony C Johnson, Rocco Latorre, Casey O Ligon, Beverley Greenwood-Van Meerveld
In vivo optogenetics identifies brain circuits controlling behaviors in conscious animals by using light to alter neuronal function and offers a novel tool to study the brain-gut axis. Using adenoviral-mediated expression, we aimed to investigate whether photoactivation with channelrhodopsin (ChR2) or photoinhibition with halorhodopsin (HR3.0) of fibers originating from the central nucleus of the amygdala (CeA) at the bed nucleus of the stria terminalis (BNST) had any effect on colonic sensitivity. We also investigated whether that there was any deleterious effect of the adenovirus on the neuronal population or the neuronal phenotype within the CeA-BNST circuitry activated during the optogenetic stimulation...
December 14, 2017: American Journal of Physiology. Gastrointestinal and Liver Physiology
https://www.readbyqxmd.com/read/29351373/a-facile-space-confined-solid-phase-sulfurization-strategy-for-growth-of-high-quality-ultrathin-molybdenum-disulfide-single-crystals
#4
Dawei Li, Zhiyong Xiao, Sai Mu, Fei Wang, Ying Liu, Jingfeng Song, Xi Huang, Lijia Jiang, Jun Xiao, Lei Liu, Stephen Ducharme, Bai Cui, Xia Hong, Lan Jiang, Jean-Francois Silvain, Yongfeng Lu
Single-crystal transition metal dichalcogenides (TMDs) and TMD-based hetero-junctions have recently attracted significant research and industrial interest owing to their intriguing optical and electrical properties. However, the lack of a simple, low-cost, environmentally friendly, synthetic method and a poor understanding of the growth mechanism post a huge challenge to implementing TMDs in practical applications. In this work, we developed a novel approach for direct formation of high-quality, monolayer and few-layer MoS2 single crystal domains via a single-step rapid thermal processing of a sandwiched reactor with sulfur and molybdenum (Mo) film in a confined reaction space...
January 19, 2018: Nano Letters
https://www.readbyqxmd.com/read/29351265/development-of-antimicrobial-biocomposite-films-to-preserve-the-quality-of-bread
#5
Kelly J Figueroa-Lopez, Margarita María Andrade-Mahecha, Olga Lucía Torres-Vargas
This study focused on the development of gelatin-based films with incorporation of microcrystalline cellulose as reinforcement material. Clove (Syzygium aromaticum), nutmeg (Myristica fragrans), and black pepper (Piper nigrum) oleoresins containing antimicrobial compounds of natural origin were incorporated into the films. The mechanical, thermal, optical, and structural properties, as well as color, seal strength and permeability to water vapor, light, and oil of the films were determined. Adding oleoresins to the gelatin matrix increased the elongation of the material and significantly diminished its permeability to water vapor and oil...
January 19, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29351258/a-polymer-optical-fiber-temperature-sensor-based-on-material-features
#6
Arnaldo Leal-Junior, Anselmo Frizera-Netoc, Carlos Marques, Maria José Pontes
This paper presents a polymer optical fiber (POF)-based temperature sensor. The operation principle of the sensor is the variation in the POF mechanical properties with the temperature variation. Such mechanical property variation leads to a variation in the POF output power when a constant stress is applied to the fiber due to the stress-optical effect. The fiber mechanical properties are characterized through a dynamic mechanical analysis, and the output power variation with different temperatures is measured...
January 19, 2018: Sensors
https://www.readbyqxmd.com/read/29351087/a-depth-encoding-pet-detector-using-light-sharing-and-single-ended-readout-with-sipms
#7
Zhonghua Kuang, Qian Yang, Xiaohui Wang, Xin Fu, Ning Ren, Ziru Sang, San Wu, Yunfei Zheng, Xianming Zhang, Zhanli Hu, Junwei Du, Dong Liang, Xin Liu, Hairong Zheng, Yongfeng Yang
Detectors with depth encoding capability and good timing resolution are required to develop a high-performance whole-body or total-body PET scanner. In this work, depth-encoding PET detectors using light sharing between two discrete crystals and single-ended readout with SiPMs were manufactured and evaluated. The detectors consisted of two unpolished LYSO crystals of 3×3×20 mm3 with different coupling materials between them and were read out by Hamamatsu 3×3 mm2 SiPMs with one-to-one coupling. The ratio of the energy of one SiPM to the total energy of two SiPMs is used to measure the depth of interaction (DOI)...
January 19, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29350958/double-weyl-phonons-in-transition-metal-monosilicides
#8
Tiantian Zhang, Zhida Song, A Alexandradinata, Hongming Weng, Chen Fang, Ling Lu, Zhong Fang
We employed ab initio calculations to identify a class of crystalline materials of MSi (M=Fe, Co, Mn, Re, Ru) having double-Weyl points in both their acoustic and optical phonon spectra. They exhibit novel topological points termed "spin-1 Weyl point" at the Brillouin zone center and "charge-2 Dirac point" at the zone corner. The corresponding gapless surface phonon dispersions are two helicoidal sheets whose isofrequency contours form a single noncontractible loop in the surface Brillouin zone. In addition, the global structure of the surface bands can be analytically expressed as double-periodic Weierstrass elliptic functions...
January 5, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29350956/negative-mass-instability-of-the-spin-and-motion-of-an-atomic-gas-driven-by-optical-cavity-backaction
#9
Jonathan Kohler, Justin A Gerber, Emma Dowd, Dan M Stamper-Kurn
We realize a spin-orbit interaction between the collective spin precession and center-of-mass motion of a trapped ultracold atomic gas, mediated by spin- and position-dependent dispersive coupling to a driven optical cavity. The collective spin, precessing near its highest-energy state in an applied magnetic field, can be approximated as a negative-mass harmonic oscillator. When the Larmor precession and mechanical motion are nearly resonant, cavity mediated coupling leads to a negative-mass instability, driving exponential growth of a correlated mode of the hybrid system...
January 5, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29350953/charged-polaron-polaritons-in-an-organic-semiconductor-microcavity
#10
Chiao-Yu Cheng, Rijul Dhanker, Christopher L Gray, Sukrit Mukhopadhyay, Eric R Kennehan, John B Asbury, Anatoliy Sokolov, Noel C Giebink
We report strong coupling between light and polaron optical excitations in a doped organic semiconductor microcavity at room temperature. Codepositing MoO_{3} and the hole transport material 4, 4^{'}-cyclohexylidenebis[N, N-bis(4-methylphenyl)benzenamine] introduces a large hole density with a narrow linewidth optical transition centered at 1.8 eV and an absorption coefficient exceeding 10^{4}  cm^{-1}. Coupling this transition to a Fabry-Pérot cavity mode yields upper and lower polaron polariton branches that are clearly resolved in angle-dependent reflectivity with a vacuum Rabi splitting ℏΩ_{R}>0...
January 5, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29350937/light-stops-at-exceptional-points
#11
Tamar Goldzak, Alexei A Mailybaev, Nimrod Moiseyev
Almost twenty years ago, light was slowed down to less than 10^{-7} of its vacuum speed in a cloud of ultracold atoms of sodium. Upon a sudden turn-off of the coupling laser, a slow light pulse can be imprinted on cold atoms such that it can be read out and converted into a photon again. In this process, the light is stopped by absorbing it and storing its shape within the atomic ensemble. Alternatively, the light can be stopped at the band edge in photonic-crystal waveguides, where the group speed vanishes...
January 5, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29350908/light-modulation-and-water-splitting-enhancement-using-composite-porous-gan-structure
#12
Chao Yang, Xin Xi, Zhi-Guo Yu, Haicheng Cao, Jing Li, Shan Lin, Zhanhong Ma, Lixia Zhao
Based on the laterally porous GaN, we designed and fabricated composite GaN porous structures with both well-ordered lateral and vertical holes. Compared to the plane GaN, the composite porous GaN structure with the combination of the vertical holes can help to reduce the UV reflectance, and increase the saturation photocurrent density during the water splitting by a factor of ~4.5. Furthermore, we investigated the underlying mechanism for the enhancement of the water splitting performance using FDTD method...
January 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29350901/adsorption-and-diffusion-of-lithium-and-sodium-on-defective-rhenium-disulfide-a-first-principles-study
#13
Sankha Mukherjee, Avinav Banwait, Sean Grixti, Nikhil A Koratkar, Chandra Veer Singh
Single layer Rhenium disulfide (ReS2) is a unique material with distinctive, anisotropic electronic, mechanical and optical properties and has the potential to be used as an anode in alkali metal ion batteries. In this work, first principles calculations were performed to systematically evaluate the potential of monolayer pristine and defective ReS2 as anodes in lithium (Li) and sodium (Na)-ion batteries. Our calculations suggest that there are several potential adsorption sites for Li and Na on pristine ReS2, owing to its low-symmetry structure...
January 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29350732/complete-amplitude-and-phase-control-of-light-using-broadband-holographic-metasurfaces
#14
Gun-Yeal Lee, Gwanho Yoon, Seung-Yeol Lee, Hansik Yun, Jaebum Cho, Kyookeun Lee, Hwi Kim, Junsuk Rho, Byoungho Lee
Reconstruction of light profiles with amplitude and phase information, called holography, is an attractive optical technology with various significant applications such as three-dimensional imaging and optical data storage. Subwavelength spatial control of both amplitude and phase of light is an essential requirement for an ideal hologram. However, traditional holographic devices suffer from their restricted capabilities of incomplete modulation in both amplitude and phase of visible light; this results in sacrifice of optical information and undesirable occurrences of critical noises in holographic images...
January 19, 2018: Nanoscale
https://www.readbyqxmd.com/read/29350691/a-novel-mutation-leu396arg-in-opa1-is-associated-with-a-severe-phenotype-in-a-large-dominant-optic-atrophy-pedigree
#15
M J Schnieders, W Goar, M Griess, B R Roos, T E Scheetz, E M Stone, J H Fingert
No abstract text is available yet for this article.
January 19, 2018: Eye
https://www.readbyqxmd.com/read/29350630/gaas-quantum-dots-in-a-gap-nanowire-photodetector
#16
Paul Kuyanov, Simon McNamee, Ray R LaPierre
We report the structural, optical and electrical properties of GaAs quantum dots (QDs) embedded along GaP nanowires. The GaP nanowires contained p-i-n junctions with 15 GaAs QDs within the intrinsic region. The nanowires were grown by molecular beam epitaxy using the self-assisted vapor-liquid-solid process. The crystal structure of the NW alternated between twinned ZB and WZ as the composition along the NW alternated between the GaP barriers and the GaAs QDs, respectively, leading to a polytypic structure with a periodic modulation of the NW sidewall facets...
January 19, 2018: Nanotechnology
https://www.readbyqxmd.com/read/29350627/franck-condon-shift-assessment-in-2d-mos-sub-2-sub
#17
Sunny Gupta, Sharmila N Shirodkar, Daniel Kaplan, Venkataraman Swaminathan, Boris I Yakobson
Optical spectroscopy (OS) techniques are often coupled with first-principles density functional theoretical (DFT) calculations for determining the precise influence of defects on the electronic and structural properties of two dimensional (2D) TMDs. Such calculations are carried out presuming there is little or no effect of vibrational transitions on the observed electronic spectrum. However, if the effect of change in vibrational energy [Franck Condon (FC) shift] associated with such a transition is large, it could possibly lead to a different origin for the observed peak...
January 19, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29350626/high-mobility-in-sub-0-75-sub-ga-sub-0-25-sub-as-quantum-wells-in-an-inas-phonon-lattice
#18
Chong Chen, Stuart N Holmes, Ian Farrer, Harvey E Beere, David A Ritchie
InGaAs based devices are great complements to silicon for CMOS, as they provide an increased carrier saturation velocity, lower operating voltage and reduced power dissipation. In this work we show that In0.75Ga0.25As quantum wells with a high mobility, 15 000 to 20 000 cm2/V.s at ambient temperature, show an InAs-like phonon with an energy of 28.8 meV, frequency of 232 cm-1 that dominates the polar-optical mode scattering from ∼ 70 K to 300 K. The optical phonon frequency is insensitive to the carrier density modulated with a surface gate or LED illumination...
January 19, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29350625/dynamically-tunable-interface-states-in-1d-graphene-embedded-photonic-crystal-heterostructure
#19
Zhao Huang, Shuaifeng Li, Xin Liu, Degang Zhao, Lei Ye, Xuefeng Zhu, Jianfeng Zang
Optical interface states exhibit promising applications in nonlinear photonics, low-threshold lasing, and surface-wave assisted sensing. However, the further application of interface states in configurable optics is hindered by their limited tunability. Here, we demonstrate a new approach to generate dynamically tunable and angle-resolved interface states using graphene-embedded photonic crystal (GPC) heterostructure device. By combining the GPC structure design with in situ electric doping of graphene, a continuously tunable interface state can be obtained and its tuning range is as wide as the full bandgap...
January 19, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29350531/on-the-electronic-structure-of-cu-chlorophyllin-and-its-breakdown-products-a-carbon-k-edge-x-ray-absorption-spectroscopy-study
#20
Katharina Witte, Ioanna Mantouvalou, Rocío Sánchez-de-Armas, Heiko Lokstein, Janina Lebendig-Kuhla, Adrian Jonas, Friedrich Roth, Birgit Kanngiesser, Holger Stiel
Using Near-Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS) the carbon backbone of sodium copper chlorophyllin (SCC), a widely used chlorophyll derivative, and its breakdown products are analyzed to elucidate their electronic structure and physicochemical properties. Using various sample preparation methods and complementary spectroscopic methods (including UV/VIS, X-ray Photoelectron Spectroscopy), a comprehensive insight into the SCC breakdown process is presented. The experimental results are supported by Density Functional Theory (DFT) calculations allowing a detailed assignment of characteristic NEXAFS-features to specific C-bonds...
January 19, 2018: Journal of Physical Chemistry. B
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