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Bingdang Wu, Minghui Yang, Ran Yin, Shujuan Zhang
Light source is a crucial factor in the application of a photochemical process, which determines the energy efficiency. The performances of acetylacetone (AA) in conversion of aqueous contaminants under irradiation with a low-pressure mercury lamp, a medium-pressure mercury lamp, a xenon lamp, and natural sunlight were investigated and compared with those of H2O2 as reference. In all cases, AA was superior to H2O2 in the degradation of Acid Orange 7. Using combinations of the different light sources with various cut-off and band-pass filters, the spectra responses of the absorbed photons in the UV/AA and UV/H2O2 processes were determined for two colored and two colorless compounds...
April 10, 2017: Journal of Hazardous Materials
Pietro P Falciglia, Stefano Romano, Federico G A Vagliasindi
This paper examines the application of cement (C)-barite (Ba) based-Stabilisation/Solidification (S/S) for the remediation of (137)Cs-contaminated soils, investigating the influence of soil: grout and C: Ba ratios on the shielding performance of the S/S mix assessed as gamma radiation shielding (γRS) index variation. Results from experiments were used to perform a novel approach and an economic analysis in order to calculate the effective dose reduction achievable by S/S and to assess the optimum quantities and costs of selected mixes, respectively...
April 19, 2017: Journal of Environmental Management
Huanjun Ding, Sabee Molloi
PURPOSE: To investigate the feasibility of accurate quantification of iodine mass thickness in contrast-enhanced spectral mammography. MATERIALS AND METHODS: A computer simulation model was developed to evaluate the performance of a photon-counting spectral mammography system in the application of contrast-enhanced spectral mammography. A figure-of-merit (FOM), which was defined as the decomposed iodine signal-to-noise ratio (SNR) with respect to the square root of the mean glandular dose (MGD), was chosen to optimize the imaging parameters, in terms of beam energy, splitting energy, and pre-filtrations for breasts of various thicknesses and densities...
April 22, 2017: Medical Physics
Sridhar Yaddanapudi, Bin Cai, Taylor Harry, Steven Dolly, Baozhou Sun, Hua Li, Keith Stinson, Camille Noel, Lakshmi Santanam, Todd Pawlicki, Sasa Mutic, S Murty Goddu
PURPOSE: The purpose of this study was to develop a novel process for using on-board MV and kV Electronic Portal Imaging Devices (EPIDs) to perform linac acceptance testing (AT) for two reasons: 1) to standardize the assessment of new equipment performance, and 2) to reduce the time to clinical use while reducing physicist workload. METHODS AND MATERIALS: In this study, Varian TrueBeam linacs equipped with amorphous silicon based EPID (aS1000) were used. The conventional set of AT tests and tolerances were used as a baseline guide...
April 22, 2017: Medical Physics
Stefano Stassi, Alessandro Chiadò, Giuseppe Calafiore, Gianluca Palmara, Stefano Cabrini, Carlo Ricciardi
Fano resonance refers to an interference between localized and continuum states that was firstly reported for atomic physics and solid-state quantum devices. In recent years, Fano interference gained more and more attention for its importance in metamaterials, nanoscale photonic devices, plasmonic nanoclusters and surface-enhanced Raman scattering (SERS). Despite such interest in nano-optics, no experimental evidence of Fano interference was reported up to now for purely nanomechanical resonators, even if classical mechanical analogies were referred from a theoretical point of view...
April 21, 2017: Scientific Reports
Haitong Yu, Dong Liu, Zhen Yang, Yuanyuan Duan
We show theoretically that 2D rectangular gratings on the surface of GaSb can serve as an "anti-reflection" pattern for nano-gap thermophotovoltaic (TPV) devices, which significantly enhances near-field radiative flux from the emitter to a GaSb cell, thus improving output power and conversion efficiency. The system in this study is a 200-nm gap TPV power generation system with a planar infrared plasmonic emitter and GaSb cell. Rigorous coupled-wave analysis is used to calculate the spectral near-field radiative flux involving periodic structures...
April 21, 2017: Scientific Reports
Emily Stuntz, Yusi Gong, Disha Sood, Volha Liaudanskaya, Dimitra Pouli, Kyle P Quinn, Carlo Alonzo, Zhiyi Liu, David L Kaplan, Irene Georgakoudi
As neurodegenerative conditions are increasingly linked to mitochondrial dysfunction, methods for studying brain cell metabolism at high spatial resolution are needed to elucidate neurodegeneration mechanisms. Two-photon excited fluorescence (TPEF) imaging is a non-destructive, high-resolution technique for studying cell metabolism via endogenous fluorescence of reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD). We employed TPEF to study the metabolism of primary rat astrocyte and neuronal cultures under normal growth conditions and in response to manganese (Mn) treatment...
April 21, 2017: Scientific Reports
Michael C Einstein, Pierre-Olivier Polack, Duy T Tran, Peyman Golshani
Low frequency membrane potential (Vm) oscillations were once thought to only occur in sleeping and anesthetized states. Recently, low frequency Vm oscillations have been described in inactive awake animals, but it is unclear if they shape sensory processing in neurons and whether they occur during active awake behavioral states. To answer these questions, we performed two-photon guided whole-cell Vm recordings from primary visual cortex layer 2/3 excitatory and inhibitory neurons in awake mice during passive visual stimulation and performance of visual and auditory discrimination tasks...
April 21, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Itsuro Morishima, Kenji Okumura, Hideyuki Tsuboi, Yasuhiro Morita, Kensuke Takagi, Ruka Yoshida, Hiroaki Nagai, Toshiro Tomomatsu, Yoshihiro Ikai, Kazushi Terada, Takahito Sone, Toyoaki Murohara
Aims: Left-ventricular (LV) scarring may be associated with a poor response to cardiac resynchronization therapy (CRT). The automatic analysis of myocardial perfusion single-photon emission computed tomography (MP-SPECT) may provide objective quantification of LV scarring. We investigated the impact of LV scarring determined by an automatic analysis of MP-SPECT on short-term LV volume response as well as long-term outcome. Methods and Results: We studied consecutive 51 patients who were eligible to undergo 99mTc-MIBI MP-SPECT both at baseline and 6 months after CRT (ischaemic cardiomyopathies 31%)...
April 1, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Agnieszka Giżewska, Ewa Witkowska-Patena, Sebastian Osiecki, Andrzej Mazurek, Zofia Stembrowicz-Nowakowska, Mirosław Dziuk
OBJECTIVES: Sentinel lymph node (SLN) mapping is currently a routine technique in breast cancer management and preoperative scintigraphic imaging plays a crucial role in the process of SLN detection. The guidelines recommend performing planar acquisition and optional single-photon emission tomography/computed tomography (SPECT/CT) imaging. The aim of this study was to verify whether routine performing of SPECT/CT in addition to planar imaging increases the sensitivity of SLN detection in patients with early-stage breast cancer...
April 20, 2017: Nuclear Medicine Communications
Ching-Ching Yang, Bang-Hung Yang, Chun-Yuan Tu, Tung-Hsin Wu, Shu-Hsin Liu
PURPOSE: This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). METHODS: One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult...
April 20, 2017: Nuclear Medicine Communications
Julien Priamo, Dionysos Adamopoulos, Oliver Rager, Angela Frei, Stephane Noble, David Carballo, Osman Ratib, René Nkoulou
BACKGROUND: Hybrid PET/MRI allows the acquisition of both fluorine-18-fluorodeoxyglucose (F-FDG) PET and cardiac magnetic resonance (CMR) during one session. Whether this will result in different referral to coronary revascularization (CR) is unknown. We compared this new hybrid method with all-nuclear/all-CMR methods in the assessment of viable myocardium and in downstream referral to CR. PATIENTS AND METHODS: Overall, 12 patients with rest perfusion defects on a single photon emission computed tomography (SPECT) were recruited for cardiac viability assessment using a PET/MRI device...
April 20, 2017: Nuclear Medicine Communications
Yasuhiro Maruoka, Michinobu Nagao, Shingo Baba, Takuro Isoda, Yoshiyuki Kitamura, Yuzo Yamazaki, Koichiro Abe, Masayuki Sasaki, Kohtaro Abe, Hiroshi Honda
OBJECTIVE: Balloon pulmonary angioplasty (BPA) is used for inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but its effect cannot be evaluated noninvasively. We devised a noninvasive quantitative index of response to BPA using three-dimensional fractal analysis (3D-FA) of technetium-99m-macroaggregated albumin (Tc-MAA) single-photon emission computed tomography (SPECT). PATIENTS AND METHODS: Forty CTEPH patients who underwent pulmonary perfusion scintigraphy and mean pulmonary arterial pressure (mPAP) measurement by right heart catheterization before and after BPA were studied...
April 20, 2017: Nuclear Medicine Communications
Erkan Senses, Siyam M Ansar, Christopher L Kitchens, Yimin Mao, Suresh Narayanan, Bharath Natarajan, Antonio Faraone
Using neutron spin-echo spectroscopy, x-ray photon correlation spectroscopy, and bulk rheology, we studied the effect of particle size on the single-chain dynamics, particle mobility, and bulk viscosity in athermal polyethylene oxide-gold nanoparticle composites. The results reveal a ≈25% increase in the reptation tube diameter with the addition of nanoparticles smaller than the entanglement mesh size (≈5  nm), at a volume fraction of 20%. The tube diameter remains unchanged in the composite with larger (20 nm) nanoparticles at the same loading...
April 7, 2017: Physical Review Letters
V V Flambaum, M V Romalis
Anisotropy in the speed of light that has been constrained by Michelson-Morley-type experiments also generates anisotropy in the Coulomb interactions. This anisotropy can manifest itself as an energy anisotropy in nuclear and atomic experiments. Here the experimental limits on Lorentz violation in _{10}^{21}Ne are used to improve the limits on Lorentz symmetry violations in the photon sector, namely, the anisotropy of the speed of light and the Coulomb interactions, by 7 orders of magnitude in comparison with previous experiments: the speed of light is isotropic to a part in 10^{28}...
April 7, 2017: Physical Review Letters
T Astner, S Nevlacsil, N Peterschofsky, A Angerer, S Rotter, S Putz, J Schmiedmayer, J Majer
We report coherent coupling between two macroscopically separated nitrogen-vacancy electron spin ensembles in a cavity quantum electrodynamics system. The coherent interaction between the distant ensembles is directly detected in the cavity transmission spectrum by observing bright and dark collective multiensemble states and an increase of the coupling strength to the cavity mode. Additionally, in the dispersive limit we show transverse ensemble-ensemble coupling via virtual photons.
April 7, 2017: Physical Review Letters
Simon E Nigg, Andreas Fuhrer, Daniel Loss
We present a scalable hybrid architecture for the 2D surface code combining superconducting resonators and hole-spin qubits in nanowires with tunable direct Rashba spin-orbit coupling. The backbone of this architecture is a square lattice of capacitively coupled coplanar waveguide resonators each of which hosts a nanowire hole-spin qubit. Both the frequency of the qubits and their coupling to the microwave field are tunable by a static electric field applied via the resonator center pin. In the dispersive regime, an entangling two-qubit gate can be realized via a third order process, whereby a virtual photon in one resonator is created by a first qubit, coherently transferred to a neighboring resonator, and absorbed by a second qubit in that resonator...
April 7, 2017: Physical Review Letters
Sumanta Das, Vincent E Elfving, Sanli Faez, Anders S Sørensen
We propose an efficient light-matter interface at optical frequencies between a single photon and a superconducting qubit. The desired interface is based on a hybrid architecture composed of an organic molecule embedded inside an optical waveguide and electrically coupled to a superconducting qubit placed near the outside surface of the waveguide. We show that high fidelity, photon-mediated, entanglement between distant superconducting qubits can be achieved with incident pulses at the single photon level. Such a low light level is highly desirable for achieving a coherent optical interface with superconducting qubit, since it minimizes decoherence arising from the absorption of light...
April 7, 2017: Physical Review Letters
A Aguilar-Arevalo, D Amidei, X Bertou, M Butner, G Cancelo, A Castañeda Vázquez, B A Cervantes Vergara, A E Chavarria, C R Chavez, J R T de Mello Neto, J C D'Olivo, J Estrada, G Fernandez Moroni, R Gaïor, Y Guardincerri, K P Hernández Torres, F Izraelevitch, A Kavner, B Kilminster, I Lawson, A Letessier-Selvon, J Liao, A Matalon, V B B Mello, J Molina, P Privitera, K Ramanathan, Y Sarkis, T Schwarz, M Settimo, M Sofo Haro, R Thomas, J Tiffenberg, E Tiouchichine, D Torres Machado, F Trillaud, X You, J Zhou
We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30  eV c^{-2} with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter κ is competitive with constraints from solar emission, reaching a minimum value of 2.2×10^{-14} at 17  eV c^{-2}. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12  eV c^{-2} and the first demonstration of direct experimental sensitivity to ionization signals <12  eV from dark matter interactions...
April 7, 2017: Physical Review Letters
Cheng Wu, Bing Bai, Yang Liu, Xiaoming Zhang, Meng Yang, Yuan Cao, Jianfeng Wang, Shaohua Zhang, Hongyan Zhou, Xiheng Shi, Xiongfeng Ma, Ji-Gang Ren, Jun Zhang, Cheng-Zhi Peng, Jingyun Fan, Qiang Zhang, Jian-Wei Pan
Random numbers are indispensable for a variety of applications ranging from testing physics foundations to information encryption. In particular, nonlocality test provide strong evidence for our current understanding of nature-quantum mechanics. All the random number generators (RNGs) used for the existing tests are constructed locally, making the test results vulnerable to the freedom-of-choice loophole. We report an experimental realization of RNGs based on the arrival time of cosmic photons. The measurement outcomes (raw data) pass the standard NIST statistical test suite...
April 7, 2017: Physical Review Letters
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