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https://www.readbyqxmd.com/read/28728024/origins-of-cell-type-specific-olfactory-processing-in-the-drosophila-mushroom-body-circuit
#1
Kengo Inada, Yoshiko Tsuchimoto, Hokto Kazama
How cell-type-specific physiological properties shape neuronal functions in a circuit remains poorly understood. We addressed this issue in the Drosophila mushroom body (MB), a higher olfactory circuit, where neurons belonging to distinct glomeruli in the antennal lobe feed excitation to three types of intrinsic neurons, α/β, α'/β', and γ Kenyon cells (KCs). Two-photon optogenetics and intracellular recording revealed that whereas glomerular inputs add similarly in all KCs, spikes were generated most readily in α'/β' KCs...
July 19, 2017: Neuron
https://www.readbyqxmd.com/read/28727865/proton-beam-radiotherapy-and-concurrent-chemotherapy-for-unresectable-stage-iii-non-small-cell-lung-cancer-final-results-of-a-phase-2-study
#2
Joe Y Chang, Vivek Verma, Ming Li, Wencheng Zhang, Ritsuko Komaki, Charles Lu, Pamela K Allen, Zhongxing Liao, James Welsh, Steven H Lin, Daniel Gomez, Melenda Jeter, Michael O'Reilly, Ronald X Zhu, Xiaodong Zhang, Heng Li, Radhe Mohan, John V Heymach, Ara A Vaporciyan, Stephen Hahn, James D Cox
Importance: Proton beam radiotherapy (PBT) has the potential to reduce toxic effects in the definitive management of locally advanced non-small-cell lung cancer (NSCLC), but long-term prospective data are lacking. Objective: To report the final (5-year) results of a prospective study evaluating concurrent chemotherapy and high-dose PBT to treat unresectable stage III NSCLC. Design, Setting, and Participants: In this open-label, single-group assignment study, with median follow-up of 27...
July 20, 2017: JAMA Oncology
https://www.readbyqxmd.com/read/28727458/unraveling-the-high-voc-and-high-performance-of-integrated-perovskite-organic-bulk-heterojunction-solar-cells
#3
Shiqi Dong, Yongsheng Liu, Ziruo Hong, En-Ping Yao, Pengyu Sun, Lei Meng, Yuze Lin, Jinsong Huang, Gang Li, Yang Yang
We have demonstrated high performance integrated perovskite/bulk-heterojunction (BHJ) solar cells due to the low carrier recombination velocity, high open circuit voltage (Voc) and increased light absorption ability in near-infrared (NIR) region of integrated devices. In particular, we find that the Voc of the integrated devices is dominated by (or pinned to) the perovskite cells, not the OPV cells. A Quasi-Fermi Level Pinning Model was proposed to understand the working mechanism and the origin of the Voc of the integrated perovskite/BHJ solar cell, which following that of the perovskite solar cell and is much higher than that of the low bandgap polymer based organic BHJ solar cell...
July 20, 2017: Nano Letters
https://www.readbyqxmd.com/read/28727440/sensitization-of-nanocrystalline-metal-oxides-with-a-phosphonate-functionalized-perylene-diimide-for-photoelectrochemical-water-oxidation-with-a-coo%C3%A2-catalyst
#4
Joel Thomas Kirner, Richard G Finke
A planar organic thin-film composed of a perylene diimide dye (N,N´-bis(phosphonomethyl)-3,4,9,10-perylenediimide, PMPDI) with photoelectrochemically deposited cobalt oxide (CoOx) catalyst was previously shown to photoelectrochemically oxidize water (DOI: 10.1021/am405598w). Herein, the same PMPDI dye is studied for the sensitization of different nanostructured metal oxide (nano-MOₓ) films in a dye-sensitized photoelectrochemical cell architecture. Dye adsorption kinetics and saturation decreases in the order TiO₂ > SnO₂ > WO₃...
July 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28727436/evidence-for-ultra-low-energy-vibrations-in-large-organic-molecules
#5
Hui Chen, Thomas Pope, Zhuoyan Wu, Dongfei Wang, Lei Tao, De-Liang Bao, Wende Xiao, Jun-Long Zhang, Yu-Yang Zhang, Shi-Xuan Du, Song Gao, Sokrates T Pantelides, Werner A Hofer, Hong-Jun Gao
The quantum efficiency or the rate of conversion of incident photon to free electron in photosynthesis is known to be extremely high. It has long been thought that the origin of this efficiency are molecular vibrations leading to a very fast separation of electrons and holes within the involved molecules. However, molecular vibrations are commonly in the range above 100 meV, which is too high for excitations in an ambient environment. Here, we analyze experimental spectra of single organic molecules on metal surfaces at ~ 4 K, which often exhibit a pronounced dip...
July 20, 2017: Nano Letters
https://www.readbyqxmd.com/read/28727320/plasmonic-gold-nanostars-incorporated-into-high-efficiency-perovskite-solar-cells
#6
Munkhbayar Batmunkh, Thomas Macdonald, William Peveler, Abdulaziz Bati, Claire J Carmalt Claire J Carmalt, Ivan Parkin, Joseph George Shapter
Incorporating appropriate plasmonic nanostructures into photovoltaic (PV) systems is of great utility for enhancing photon absorption and thus improving device performance. Herein, the successful integration of plasmonic gold nanostars (AuNSs) into mesoporous TiO2 photoelectrodes for perovskite solar cells (PSCs) is reported. The PSCs fabricated with TiO2-AuNSs photoelectrodes exhibited a device efficiency of up to 17.72%, while the control cells without AuNSs showed a maximum efficiency of 15.19%. We attribute the origin of increased device performance to enhanced light absorption and suppressed charge recombination...
July 20, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28726968/evaluation-of-spectral-photon-counting-computed-tomography-k-edge-imaging-for-determination-of-gold-nanoparticle-biodistribution-in-vivo
#7
Salim Si-Mohamed, David P Cormode, Daniel Bar-Ness, Monica Sigovan, Pratap C Naha, Jean-Baptiste Langlois, Lara Chalabreysse, Philippe Coulon, Ira Blevis, Ewald Roessl, Klaus Erhard, Loic Boussel, Philippe Douek
Spectral photon counting computed tomography (SPCCT) is an emerging medical imaging technology. SPCCT scanners record the energy of incident photons, which allows specific detection of contrast agents due to measurement of their characteristic X-ray attenuation profiles. This approach is known as K-edge imaging. Nanoparticles formed from elements such as gold, bismuth or ytterbium have been reported as potential contrast agents for SPCCT imaging. Furthermore, gold nanoparticles have many applications in medicine, such as adjuvants for radiotherapy and photothermal ablation...
July 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28726960/robust-triplet-triplet-annihilation-photon-upconversion-by-efficient-oxygen-scavenging
#8
Damir Dzebo, Kasper Moth-Poulsen, Bo Albinsson
We hereby present a simple method for reducing the effect of oxygen quenching in Triplet-Triplet Annihilation Upconversion (TTA-UC) systems. A number of commercially available thioethers and one thiol have been tested as singlet oxygen scavengers. Recording of the upconverted emission from a well-studied PdOEP (sensitizer)-DPA (annihilator/emitter) couple has been made over time with steady-state excitation capturing the steady-state kinetics of the TTA-UC process as the solubilized oxygen is depleted by reaction with the scavengers...
July 20, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28726938/design-and-characterization-of-a-plasmonic-doppler-grating-for-azimuthal-angle-resolved-surface-plasmon-resonances
#9
Kel-Meng See, Fan-Cheng Lin, Jer-Shing Huang
We present a two-dimensional plasmonic Doppler grating (PDG) for broadband and azimuthal angle-resolved nanophotonic applications. The PDG consists of a set of non-concentric circular rings mimicking the wavefronts of a moving point source that exhibits the Doppler effect and thereby offers a continuous azimuthal angle-dependent lattice momentum for photon-plasmon coupling. The center and span of the working frequency window are fully designable for optimal performance in specific applications. We detail the design, fabrication and optical characterization of the PDG...
July 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28726724/theoretical-studies-on-two-photon-fluorescent-hg-2-probes-based-on-the-coumarin-rhodamine-system
#10
Yujin Zhang, Jiancai Leng
The development of fluorescent sensors for Hg(2+) has attracted much attention due to the well-known adverse effects of mercury on biological health. In the present work, the optical properties of two newly-synthesized Hg(2+) chemosensors based on the coumarin-rhodamine system (named Pro1 and Pro2) were systematically investigated using time-dependent density functional theory. It is shown that Pro1 and Pro2 are effective ratiometric fluorescent Hg(2+) probes, which recognize Hg(2+) by Förster resonance energy transfer and through bond energy transfer mechanisms, respectively...
July 20, 2017: Sensors
https://www.readbyqxmd.com/read/28726684/low-dose-4d-cone-beam-ct-via-joint-spatiotemporal-regularization-of-tensor-framelet-and-nonlocal-total-variation
#11
Hao Han, Hao Gao, Lei Xing
Excessive radiation exposure is still a major concern in 4D cone-beam computed tomography (4D-CBCT) due to its prolonged scanning duration. Radiation dose can be effectively reduced by either under-sampling the x-ray projections or reducing the x-ray flux. However, 4D-CBCT reconstruction under such low-dose protocols is prone to image artifacts and noise. In this work, we propose a novel joint regularization-based iterative reconstruction method for low-dose 4D-CBCT. To tackle the under-sampling problem, we employ spatiotemporal tensor framelet (STF) regularization to take advantage of the spatiotemporal coherence of the patient anatomy in 4D images...
July 20, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28726679/accuracy-of-rhenium-188-spect-ct-activity-quantification-for-applications-in-radionuclide-therapy-using-clinical-reconstruction-methods
#12
Pedro L Esquinas, Carlos F Uribe, M Gonzalez, Cristina Rodríguez-Rodríguez, Urs O Häfeli, Anna Celler
The main applications of (188)Re in radionuclide therapies include trans-arterial liver radioembolization and palliation of painful bone-metastases. In order to optimize (188)Re therapies, the accurate determination of radiation dose delivered to tumors and organs at risk is required. Single photon emission computed tomography (SPECT) can be used to perform such dosimetry calculations. However, the accuracy of dosimetry estimates strongly depends on the accuracy of activity quantification in (188)Re images...
July 20, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28726669/spectral-performance-of-a-whole-body-research-photon-counting-detector-ct-quantitative-accuracy-in-derived-image-sets
#13
Shuai Leng, Wei Zhou, Zhicong Yu, Ahmed F Halaweish, Bernhard Krauss, Bernhard Schmidt, Lifeng Yu, Steffen Kappler, Cynthia H McCollough
Photon-counting computed tomography (PCCT) uses a photon counting detector to count individual photons and allocate them to specific energy bins by comparing photon energy to preset thresholds. This enables simultaneous multi-energy CT with a single source and detector. Phantom studies were performed to assess the spectral performance of a research PCCT scanner by assessing the accuracy of derived images sets. Specifically, we assessed the accuracy of iodine quantification in iodine map images and of CT number accuracy in virtual monoenergetic images (VMI)...
July 20, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28726575/bioprinting-pattern-dependent-electrical-mechanical-behavior-of-cardiac-alginate-implants-characterization-and-ex-vivo-phase-contrast-microtomography-assessment
#14
Mohammad Izadifar, Paul Babyn, Michael E Kelly, Dean Chapman, Xiongbiao Chen
Three-dimensional (3D)-bioprinting techniques may be used to modulate electrical/mechanical properties and porosity of hydrogel constructs for fabrication of suitable cardiac implants. Notably, characterization of these properties after implantation remains a challenge, raising the need for the development of novel quantitative imaging techniques for monitoring hydrogel implant behavior in-situ. This study aims to (i) assess the influence of hydrogel bioprinting patterns on electrical/mechanical behavior of cardiac implants based on a 3D-printing technique and (ii) investigate the potential of synchrotron X-ray phase contrast computed tomography (PCI-CT) for estimating elastic modulus/impedance/porosity and microstructural features of 3D-printed cardiac implants in-situ via an ex-vivo study...
July 20, 2017: Tissue Engineering. Part C, Methods
https://www.readbyqxmd.com/read/28726383/marangoni-convection-assisted-single-molecule-detection-with-nanojet-surface-enhanced-raman-spectroscopy
#15
Te-Wei Chang, Xinhao Wang, Amirreza Mahigir, Georgios Veronis, Gang Logan Liu, Manas Ranjan Gartia
Many single-molecule (SM) label-free techniques such as scanning probe microscopies (SPM) and magnetic force spectroscopies (MFS) provide high resolution surface topography information, but lack chemical information. Typical surface enhanced Raman spectroscopy (SERS) systems provide chemical information on the analytes, but lack spatial resolution. In addition, a challenge in SERS sensors is to bring analytes into the so-called "hot spots" (locations where the enhancement of electromagnetic field amplitude is larger than 10(3))...
July 20, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28726108/why-does-the-bioluminescent-fungus-armillaria-mellea-have-luminous-mycelium-but-nonluminous-fruiting-body
#16
K V Purtov, V N Petushkov, N S Rodionova, J I Gitelson
By determining the components involved in the bioluminescence process in luminous and nonluminous organs of the honey fungus Armillaria mellea, we have established causes of partial luminescence of this fungus. The complete set of enzymes and substrates required for bioluminescence is formed only in the mycelium and only under the conditions of free oxygen access. Since the synthesis of luciferin precursor (hispidin) and 3-hydroxyhispidin hydroxylase in the fruiting bodies is blocked, the formation of luciferin-the key component of fungal bioluminescent system-was not observed...
May 2017: Doklady. Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28726093/the-fluorescence-lifetime-of-lipofuscin-granule-fluorophores-contained-in-the-retinal-pigment-epithelium-cells-from-human-cadaver-eyes-in-normal-state-and-in-the-case-of-visualized-pathology
#17
M A Yakovleva, T B Feldman, P M Arbukhanova, S A Borzenok, V A Kuzmin, M A Ostrovsky
A comparative analysis of fluorescence lifetime of lipofuscin granule fluorophores contained in the retinal pigment epithelium cells from human cadaver eyes in normal state and in the case of visualized pathology was carried out. Measurements of fluorescence lifetimes of bis-retinoids and their photooxidation and photodegradation products were carried out using the method of counting time-correlated photons. Comparative analysis showed that, in the case of visualized pathology, the contribution of photooxidation and photodegradation products of bis-retinoids to the total fluorescence of the retinal pigment epithelium cell suspension increases in comparison with the norm...
May 2017: Doklady. Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28726076/ejection-fraction-in-myocardial-perfusion-imaging-assessed-with-a-dynamic-phantom-comparison-between-iq-spect-and-lehr
#18
Eero Hippeläinen, Teemu Mäkelä, Touko Kaasalainen, Erna Kaleva
BACKGROUND: Developments in single photon emission tomography instrumentation and reconstruction methods present a potential for decreasing acquisition times. One of such recent options for myocardial perfusion imaging (MPI) is IQ-SPECT. This study was motivated by the inconsistency in the reported ejection fraction (EF) and left ventricular (LV) volume results between IQ-SPECT and more conventional low-energy high-resolution (LEHR) collimation protocols. IQ-SPECT and LEHR quantitative results were compared while the equivalent number of iterations (EI) was varied...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28725334/bloch-surface-wave-coupled-emission-at-ultra-violet-wavelengths
#19
Ramachandram Badugu, Jieying Mao, Steve Blair, Douguo Zhang, Emiliano Descrovi, Angelo Angelini, Yiping Huo, Joseph R Lakowicz
The interaction of fluorophores with nearby metallic structures is now an active area of research. Dielectric photonic structures offer some advantages over plasmonic structures, namely small energy losses and less quenching. We describe a dielectric one-dimensional photonic crystal (1DPC), which supports Bloch surface waves (BSWs) from 280 to 440 nm. This BSW structure is a quartz slide coated with alternating layers of SiO2 and Si3N4. We show that this structure displays BSWs and that the near-UV fluorophore, 2-aminopurine (2-AP), on the top surface of the structure couples with the BSWs...
December 22, 2016: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/28725052/monolithically-integrated-te-mode-1d-silicon-on-insulator-isolators-using-seedlayer-free-garnet
#20
Cui Zhang, Prabesh Dulal, Bethanie J H Stadler, David C Hutchings
The first experimental TE-mode silicon-on-insulator (SOI) isolators using Faraday Rotation are here realized to fill the 'missing link' in source-integrated near infrared photonic circuits. The isolators are simple 1D 2-element waveguides, where garnet claddings and longitudinal magnetic fields produce nonreciprocal mode conversion, the waveguide equivalent of Faraday Rotation (FR). Quasi-phase matched claddings are used to overcome the limitations of birefringence. Current experimental SOI isolators use nonreciprocal phase shift (NRPS) in interferometers or ring resonators, but to date NRPS requires TM-modes, so the TE-modes normally produced by integrated lasers cannot be isolated without many ancillary polarisation controls...
July 19, 2017: Scientific Reports
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