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https://www.readbyqxmd.com/read/28528255/molecular-structure-second-and-third-order-nonlinear-optical-properties-and-dft-studies-of-a-novel-non-centrosymmetric-chalcone-derivative-2e-3-4-fluorophenyl-1-4-1e-4-fluorophenyl-methylene-amino-phenyl-prop-2-en-1-one
#1
Shivaraj R Maidur, Parutagouda Shankaragouda Patil, Anusha Ekbote, Tze Shyang Chia, Ching Kheng Quah
In the present work, the title chalcone, (2E)-3-(4-fluorophenyl)-1-(4-{[(1E)-(4-fluorophenyl) methylene]amino}phenyl)prop-2-en-1-one (abbreviated as FAMFC), was synthesized and structurally characterized by single-crystal X-ray diffraction. The compound is crystallized in the monoclinic system with non-centrosymmetric space group P21 and hence it satisfies the essential condition for materials to exhibit second-order nonlinear optical properties. The molecular structure was further confirmed by using FT-IR and (1)H NMR spectroscopic techniques...
May 9, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28527966/suture-dehiscence-in-the-tricuspid-annulus-an-ex%C3%A2-vivo-analysis-of-tissue-strength-and-composition
#2
Deborah M Paul, Ajay Naran, Eric L Pierce, Charles H Bloodworth, Steven F Bolling, Ajit P Yoganathan
BACKGROUND: Surgical repair of functional tricuspid regurgitation (FTR) is an increasingly common practice, but annuloplasty suture dehiscence remains a significant problem. Quantitative and mechanistic understanding of annular suture holding strength can support more effective techniques for tricuspid valve device anchoring. METHODS: Suture holding strength of ovine tricuspid annuli (n = 15) was quantified ex vivo by pullout testing at 12 positions around their circumference...
May 17, 2017: Annals of Thoracic Surgery
https://www.readbyqxmd.com/read/28527910/radiative-decay-engineering-8-coupled-emission-microscopy-for-lens-free-high-throughput-fluorescence-detection
#3
Liangfu Zhu, Ramachandram Badugu, Douguo Zhang, Ruxue Wang, Emiliano Descrovi, Joseph R Lakowicz
Fluorescence spectroscopy and imaging are now used throughout the biosciences. Fluorescence microscopes, spectrofluorometers, microwell plate readers and microarray imagers all use multiple optical components to collect, redirect and focus the emission onto single point or array imaging detectors. For almost all biological samples, except those with regular nanoscale features, emission occurs in all directions. With the exception of complex microscope objectives with large collection angles (NA ≤ 0.5), all these instruments collect only a small fraction of the total emission...
May 17, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28527471/the-electron-shuffle-cerium-influences-samarium-4f-orbital-occupancy-in-heteronuclear-ce-sm-oxide-clusters
#4
Jared O Kafader, Josey E Topolski, Vicmarie Marrero-Colon, Srinivasan S Iyengar, Caroline Chick Jarrold
The anion photoelectron (PE) spectra along with supporting results of density functional theory (DFT) calculations on SmO(-), SmCeOy(-), and Sm2Oy(-) (y = 1, 2) are reported and compared to previous results on CeO(-) [M. Ray et al., J. Chem. Phys. 142, 064305 (2015)] and Ce2Oy(-) (y = 1, 2) [J. O. Kafader et al., J. Chem. Phys. 145, 154306 (2016)]. Similar to the results on CexOy(-) clusters, the PE spectra of SmO(-), SmCeOy(-), and Sm2Oy(-) (y = 1, 2) all exhibit electronic transitions to the neutral ground state at approximately 1 eV e(-)BE...
May 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28527413/monochromatic-green-light-induces-an-aberrant-accumulation-of-geranylgeranyled-chlorophylls-in-plants
#5
Zuzana Materová, Roman Sobotka, Barbora Zdvihalová, Michal Oravec, Jakub Nezval, Václav Karlický, Daniel Vrábl, Michal Štroch, Vladimír Špunda
Light quality is an important environmental factor affecting the biosynthesis of photosynthetic pigments whose production seems to be affected not only quantitatively but also qualitatively. In this work, we set out to identify unusual pigment detected in leaves of barley (Hordeum vulgare L.) and explain its presence in plants grown under monochromatic green light (GL; 500-590 nm). The chromatographic analysis (HPLC-DAD) revealed that a peak belonging to this unknown pigment is eluted between chlorophyll (Chl) a and b...
May 6, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28526891/hanbury-brown-twiss-effect-without-two-photon-interference-in-photon-counting-regime
#6
Bin Bai, Yu Zhou, Ruifeng Liu, Huaibin Zheng, Yunlong Wang, Fuli Li, Zhuo Xu
From quantum point of view, Hanbury Brown-Twiss effect is a result of constructive-destructive two-photon interference. There should be no Hanbury Brown-Twiss effect if there was no two-photon interference. In this paper, we observed Hanbury Brown- Twiss effect in a specially designed experiment, in which two-photon interference is impossible by keeping only one two-photon probability amplitude in the experimental scheme. However, our experimental results can still be interpreted by Glauber's quantum optical coherence theory...
May 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28526885/experimental-linear-optics-simulation-of-ground-state-of-an-ising-spin-chain
#7
Peng Xue, Xian Zhan, Zhihao Bian
We experimentally demonstrate a photonic quantum simulator: by using a two-spin Ising chain (an isolated dimer) as an example, we encode the wavefunction of the ground state with a pair of entangled photons. The effect of magnetic fields, leading to a critical modification of the correlation between two spins, can be simulated by just local operations. With the ratio of simulated magnetic fields and coupling strength increasing, the ground state of the system changes from a product state to an entangled state and back to another product state...
May 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28526883/openspritzer-an-open-hardware-pressure-ejection-system-for-reliably-delivering-picolitre-volumes
#8
C J Forman, H Tomes, B Mbobo, R J Burman, M Jacobs, T Baden, J V Raimondo
The ability to reliably and precisely deliver picolitre volumes is an important component of biological research. Here we describe a high-performance, low-cost, open hardware pressure ejection system (Openspritzer), which can be constructed from off the shelf components. The device is capable of delivering minute doses of reagents to a wide range of biological and chemical systems. In this work, we characterise the performance of the device and compare it to a popular commercial system using two-photon fluorescence microscopy...
May 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28525952/sb-and-n-incorporation-interplay-in-gaassbn-gaas-epilayers-near-lattice-matching-condition-for-1-0-1-16-ev-photonic-applications
#9
V Braza, D F Reyes, A Gonzalo, A D Utrilla, T Ben, J M Ulloa, D González
As promising candidates for solar cell and photodetection applications in the range 1.0-1.16 eV, the growth of dilute nitride GaAsSbN alloys lattice matched to GaAs is studied. With this aim, we have taken advantage of the temperature gradient in the molecular beam epitaxy reactor to analyse the impact of temperature on the incorporation of Sb and N species according to the wafer radial composition gradients. The results from the combination of X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopies (EDS) show an opposite rate of incorporation between N and Sb as we move away from the centre of the wafer...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28524670/generation-of-counterpropagating-path-entangled-photon-pairs-in-a-single-periodic-waveguide
#10
Sina Saravi, Thomas Pertsch, Frank Setzpfandt
We propose the use of nonlinear periodic waveguides for direct and fully integrated generation of counterpropagating photon pairs by spontaneous parametric down-conversion. Using the unique properties of Bloch modes in such periodic structures, we furthermore show that two counterpropagating phase-matching conditions can be fulfilled simultaneously, allowing for the generation of path-entangled Bell states in a single periodic waveguide. To demonstrate the feasibility of our proposal, we design a photonic crystal slab waveguide made of lithium niobate and numerically demonstrate Bell-state generation...
May 5, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28523936/experimental-spectroscopic-studies-of-carbon-monoxide-co-fluorescence-at-high-temperatures-and-pressures
#11
Olivier Carrivain, Mikael Orain, Nelly Dorval, Celine Morin, Guillaume Legros
Two-photon excitation laser-induced fluorescence of carbon monoxide (CO-LIF) is investigated experimentally in order to determine the applicability of this technique for imaging CO concentration in aeronautical combustors. Experiments are carried out in a high temperature, high-pressure test cell, and in a laminar premixed CH4/air flame. Influence of temperature and pressure on CO-LIF spectra intensity and shape is reported. The experimental results show that as pressure increases, the CO-LIF excitation spectrum becomes asymmetric...
January 1, 2017: Applied Spectroscopy
https://www.readbyqxmd.com/read/28523012/growth-and-accumulation-of-secondary-metabolites-in-perilla-as-affected-by-photosynthetic-photon-flux-density-and-electrical-conductivity-of-the-nutrient-solution
#12
Na Lu, Emmanuel L Bernardo, Chayanit Tippayadarapanich, Michiko Takagaki, Natsuko Kagawa, Wataru Yamori
The global demand for medicinal plants is increasing. The quality of plants grown outdoors, however, is difficult to control. Myriad environmental factors influence plant growth and directly impact biosynthetic pathways, thus affecting the secondary metabolism of bioactive compounds. Plant factories use artificial lighting to increase the quality of medicinal plants and stabilize production. Photosynthetic photon flux density (PPFD) and electrical conductivity (EC) of nutrient solutions are two important factors that substantially influence perilla (Perilla frutescens, Labiatae) plant growth and quality...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28522878/the-photodissociation-of-hcn-and-hnc-effects-on-the-hnc-hcn-abundance-ratio-in-the-interstellar-medium
#13
Alfredo Aguado, Octavio Roncero, Alexandre Zanchet, Marcelino Agúndez, José Cernicharo
The impact of the photodissociation of HCN and HNC isomers is analyzed in different astrophysical environments. For this purpose, the individual photodissociation cross section of HCN and HNC isomers have been calculated in the 7-13.6 eV photon energy range for a temperature of 10 K. These calculations are based on the ab initio calculation of three-dimensional adiabatic potential energy surfaces of the 21 lower electronic states. The cross sections are then obtained using a quantum wave packet calculation of the rotational transitions needed to simulate a rotational temperature of 10 K...
March 20, 2017: Astrophysical Journal
https://www.readbyqxmd.com/read/28522868/first-demonstration-of-multi-color-3-d-in-vivo-imaging-using-ultra-compact-compton-camera
#14
Aya Kishimoto, Jun Kataoka, Takanori Taya, Leo Tagawa, Saku Mochizuki, Shinji Ohsuka, Yuto Nagao, Keisuke Kurita, Mitsutaka Yamaguchi, Naoki Kawachi, Keiko Matsunaga, Hayato Ikeda, Eku Shimosegawa, Jun Hatazawa
In the field of nuclear medicine, single photon emission tomography and positron emission tomography are the two most common techniques in molecular imaging, but the available radioactive tracers have been limited either by energy range or difficulties in production and delivery. Thus, the use of a Compton camera, which features gamma-ray imaging of arbitrary energies from a few hundred keV to more than MeV, is eagerly awaited along with potential new tracers which have never been used in current modalities...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28522816/dynamical-dispersion-engineering-in-coupled-vertical-cavities-employing-a-high-contrast-grating
#15
Alireza Taghizadeh, Il-Sug Chung
Photon's effective mass is an important parameter of an optical cavity mode, which determines the strength of light-matter interaction. Here, we propose a novel method for controlling the photon's effective mass by using coupled photonic cavities and designing the angular dependence of the coupling strength. This can be implemented by employing a high-contrast grating (HCG) as the coupling reflector in a system of two coupled vertical cavities, and engineering both the HCG reflection phase and amplitude response...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28522470/three-dimensional-ca-2-imaging-advances-understanding-of-astrocyte-biology
#16
Erika Bindocci, Iaroslav Savtchouk, Nicolas Liaudet, Denise Becker, Giovanni Carriero, Andrea Volterra
Astrocyte communication is typically studied by two-dimensional calcium ion (Ca(2+)) imaging, but this method has not yielded conclusive data on the role of astrocytes in synaptic and vascular function. We developed a three-dimensional two-photon imaging approach and studied Ca(2+) dynamics in entire astrocyte volumes, including during axon-astrocyte interactions. In both awake mice and brain slices, we found that Ca(2+) activity in an individual astrocyte is scattered throughout the cell, largely compartmented between regions, preponderantly local within regions, and heterogeneously distributed regionally and locally...
May 19, 2017: Science
https://www.readbyqxmd.com/read/28522242/monitoring-the-surface-quality-of-silver-plasmon-waveguides-with-nonlinear-photoemission-electron-microscopy-and-in-situ-ion-sputtering
#17
Kellie Pearce, Francis Schuknecht, Christian Späth, Benjamin Duschner, Florian Richter, Ulf Kleineberg
We use photoemission electron microscopy (PEEM) with single- and two-photon excitation to study the properties of surface plasmon polaritons (SPPs) in tapered silver stripe waveguides. Arrays of waveguides with different widths, grating coupler geometries, and taper angles are fabricated using electron beam lithography (EBL) on Si and indium-tin-oxide (ITO)-covered glass substrates. The presence of propagating SPP modes is indicated by modulations of the non-linear photoemission intensity which run along the length of the waveguide - the result of interfering SPPs reflected from the edges...
May 10, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28522082/brain-perfusion-during-rapid-eye-movement-sleep-successfully-identifies-amnestic-mild-cognitive-impairment
#18
Pauline Brayet, Dominique Petit, Andrée-Ann Baril, Nadia Gosselin, Jean-François Gagnon, Jean-Paul Soucy, Serge Gauthier, Marie-Jeanne Kergoat, Julie Carrier, Isabelle Rouleau, Jacques Montplaisir
INTRODUCTION: Prodromal markers of Alzheimer's disease (AD) have been derived from wakefulness. However, brain perfusion during rapid-eye movement (REM) sleep could be a sensitive marker of amnestic mild cognitive impairment (aMCI), as activation of REM sleep relies more on the cholinergic system. METHODS: Eight subjects with aMCI, and 16 controls, underwent two single-photon emission computed tomography (SPECT) scans with tracer injected during REM sleep then wakefulness...
June 2017: Sleep Medicine
https://www.readbyqxmd.com/read/28521138/transformation-of-cortex-wide-emergent-properties-during-motor-learning
#19
Hiroshi Makino, Chi Ren, Haixin Liu, An Na Kim, Neehar Kondapaneni, Xin Liu, Duygu Kuzum, Takaki Komiyama
Learning involves a transformation of brain-wide operation dynamics. However, our understanding of learning-related changes in macroscopic dynamics is limited. Here, we monitored cortex-wide activity of the mouse brain using wide-field calcium imaging while the mouse learned a motor task over weeks. Over learning, the sequential activity across cortical modules became temporally more compressed, and its trial-by-trial variability decreased. Moreover, a new flow of activity emerged during learning, originating from premotor cortex (M2), and M2 became predictive of the activity of many other modules...
May 17, 2017: Neuron
https://www.readbyqxmd.com/read/28521133/camkii-autophosphorylation-is-necessary-for-optimal-integration-of-ca-2-signals-during-ltp-induction-but-not-maintenance
#20
Jui-Yun Chang, Paula Parra-Bueno, Tal Laviv, Erzsebet M Szatmari, Seok-Jin R Lee, Ryohei Yasuda
CaMKII plays a critical role in decoding calcium (Ca(2+)) signals to initiate long-lasting synaptic plasticity. However, the properties of CaMKII that mediate Ca(2+) signals in spines remain elusive. Here, we measured CaMKII activity in spines using fast-framing two-photon fluorescence lifetime imaging. Following each pulse during repetitive Ca(2+) elevations, CaMKII activity increased in a stepwise manner. Thr286 phosphorylation slows the decay of CaMKII and thus lowers the frequency required to induce spine plasticity by several fold...
May 17, 2017: Neuron
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