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William D Erwin, Aaron C Jessop, Martha V Mar, Homer A Macapinlac, Osama R Mawlawi
OBJECTIVE: The aim of this study was to assess the feasibility of IQ-SPECT gated blood pool (MUGA) under conditions of decreased scan time (ST). PATIENTS AND METHODS: Ten patients underwent routine 26-min, two-view planar, followed by LEHR and IQ-SPECT MUGA, on a Siemens dual-head Symbia scanner. Six 'back and forth' 4-min SPECT scans were summed into 4-, 8-, 12-, 16-, 20-, and 24-min equivalent scans, and reconstructed iteratively (IQ-SPECT and LEHR) and with FBP (LEHR)...
October 21, 2016: Nuclear Medicine Communications
Hyemin Kim, Won Ho Kong, Keum-Yong Seong, Dong Kyung Sung, Hyeonseon Jeong, Jin Kon Kim, Seung Yun Yang, Sei Kwang Hahn
Epidermal growth factor (EGF) has been recognized as an excellent wound healing agent due to its therapeutic function stimulating skin cell growth, proliferation and differentiation. However, the transdermal delivery of EGF poses a significant challenge due to its short half-life and lack of efficient formulation. Here, to improve the transdermal delivery efficiency, EGF was conjugated to hyaluronate (HA), which was formulated into a patch-type film for skin wound healing. HA-EGF conjugate was synthesized by coupling reaction between aldehyde-modified HA and N-terminal amine group of EGF to minimize the loss of biological activities...
October 24, 2016: Biomacromolecules
Matthew Jacobs, Martin Lopez-Garcia, O-Phart Phrathep, Tracy Lawson, Ruth Oulton, Heather M Whitney
Enhanced light harvesting is an area of interest for optimizing both natural photosynthesis and artificial solar energy capture(1,2). Iridescence has been shown to exist widely and in diverse forms in plants and other photosynthetic organisms and symbioses(3,4), but there has yet to be any direct link demonstrated between iridescence and photosynthesis. Here we show that epidermal chloroplasts, also known as iridoplasts, in shade-dwelling species of Begonia(5), notable for their brilliant blue iridescence, have a photonic crystal structure formed from a periodic arrangement of the light-absorbing thylakoid tissue itself...
October 24, 2016: Nature Plants
Pablo Alonso-González, Alexey Y Nikitin, Yuanda Gao, Achim Woessner, Mark B Lundeberg, Alessandro Principi, Nicolò Forcellini, Wenjing Yan, Saül Vélez, Andreas J Huber, Kenji Watanabe, Takashi Taniguchi, Félix Casanova, Luis E Hueso, Marco Polini, James Hone, Frank H L Koppens, Rainer Hillenbrand
Terahertz (THz) fields are widely used for sensing, communication and quality control. In future applications, they could be efficiently confined, enhanced and manipulated well below the classical diffraction limit through the excitation of graphene plasmons (GPs). These possibilities emerge from the strongly reduced GP wavelength, λp, compared with the photon wavelength, λ0, which can be controlled by modulating the carrier density of graphene via electrical gating. Recently, GPs in a graphene/insulator/metal configuration have been predicted to exhibit a linear dispersion (thus called acoustic plasmons) and a further reduced wavelength, implying an improved field confinement, analogous to plasmons in two-dimensional electron gases (2DEGs) near conductive substrates...
October 24, 2016: Nature Nanotechnology
Peter R Wiecha, Arnaud Arbouet, Christian Girard, Aurélie Lecestre, Guilhem Larrieu, Vincent Paillard
The rational design of photonic nanostructures consists of anticipating their optical response from systematic variations of simple models. This strategy, however, has limited success when multiple objectives are simultaneously targeted, because it requires demanding computational schemes. To this end, evolutionary algorithms can drive the morphology of a nano-object towards an optimum through several cycles of selection, mutation and cross-over, mimicking the process of natural selection. Here, we present a numerical technique that can allow the design of photonic nanostructures with optical properties optimized along several arbitrary objectives...
October 24, 2016: Nature Nanotechnology
Sung-Jin Jung, Seong-Kwan Hong, Oh-Kyong Kwon
A readout integrated circuit (ROIC) using two-step fastest signal identification (FSI) is proposed to reduce the number of input channels of a data acquisition (DAQ) block with a high-channel reduction ratio. The two-step FSI enables the proposed ROIC to filter out useless input signals that arise from scattering and electrical noise without using complex and bulky circuits. In addition, an asynchronous fastest signal identifier and a self-trimmed comparator are proposed to identify the fastest signal without using a high-frequency clock and to reduce misidentification, respectively...
October 20, 2016: Sensors
Zhenqin Wu, Huimin Bi, Sichen Pan, Lingyi Meng, Xin Sheng Zhao
Fluorescence correlation spectroscopy (FCS) is a powerful tool to investigate molecular diffusion and relaxations, which may be utilized to study many problems, such as molecular size and aggregation, chemical reaction, molecular transportation and motion, and various kinds of physical and chemical relaxations. This paper focuses on a problem related to using the relaxation term to study a reaction. If two species with different fluorescence photon emission efficiencies are connected by a reaction, the kinetic and equilibrium properties will be manifested in the relaxation term of the FCS curve...
October 24, 2016: Journal of Physical Chemistry. B
Panagiotis Vergyris, Thomas Meany, Tommaso Lunghi, Gregory Sauder, James Downes, M J Steel, Michael J Withford, Olivier Alibart, Sébastien Tanzilli
Beyond the use of genuine monolithic integrated optical platforms, we report here a hybrid strategy enabling on-chip generation of configurable heralded two-photon states. More specifically, we combine two different fabrication techniques, i.e., non-linear waveguides on lithium niobate for efficient photon-pair generation and femtosecond-laser-direct-written waveguides on glass for photon manipulation. Through real-time device manipulation capabilities, a variety of path-coded heralded two-photon states can be produced, ranging from product to entangled states...
October 24, 2016: Scientific Reports
Masahiro Shibuta, Kazuo Yamamoto, Tsutomu Ohta, Masato Nakaya, Toyoaki Eguchi, Atsushi Nakajima
Time-resolved two-photon photoemission (TR-2PPE) spectroscopy is employed to probe the electronic states of a C60 fullerene film formed on highly oriented pyrolytic graphite (HOPG), acting as a model two-dimensional (2D) material for multi-layered graphene. Owing to the in-plane sp(2)-hybridized nature of the HOPG, the TR-2PPE spectra reveal the energetics and dynamics of photocarriers in the C60 film: after hot excitons are nascently formed in C60 via intramolecular excitation by a pump photon, they dissociate into photocarriers of free electrons and the corresponding holes, and the electrons are subsequently detected by a probe photon as photoelectrons...
October 24, 2016: Scientific Reports
Hai-Rui Wei, Pei-Jin Zhu
It is desirable to implement an efficient quantum information process demanding fewer quantum resources. We designed two compact quantum circuits for determinately implementing four-qubit Toffoli and Fredkin gates on single-photon systems in both the polarization and spatial degrees of freedom (DoFs) via diamond nitrogen-vacancy (NV) centers in resonators. The gates are heralded by the electron spins associated with the diamond NV centers. In contrast to the ones with one DoF, our implementations reduce the quantum resource and are robust against the decoherence...
October 24, 2016: Scientific Reports
Sava Sakadžić, Mohammad A Yaseen, Rajeshwer Jaswal, Emmanuel Roussakis, Anders M Dale, Richard B Buxton, Sergei A Vinogradov, David A Boas, Anna Devor
The cerebral metabolic rate of oxygen ([Formula: see text]) is an essential parameter for evaluating brain function and pathophysiology. However, the currently available approaches for quantifying [Formula: see text] rely on complex multimodal imaging and mathematical modeling. Here, we introduce a method that allows estimation of [Formula: see text] based on a single measurement modality-two-photon imaging of the partial pressure of oxygen ([Formula: see text]) in cortical tissue. We employed two-photon phosphorescence lifetime microscopy (2PLM) and the oxygen-sensitive nanoprobe PtP-C343 to map the tissue [Formula: see text] distribution around cortical penetrating arterioles...
October 2016: Neurophotonics
Hao Wu, Fang Zeng, Hang Zhang, Jiangsheng Xu, Jianrong Qiu, Shuizhu Wu
The applications of photodynamic therapy (PDT) are usually limited by photosensitizers' side effects and singlet oxygen's short half-life. Herein, a mitochondria-targeted nanosystem is demonstrated to enhance the PDT efficacy by releasing a bio-precursor of photosensitizer under two-photon irradiation. A phototriggerable coumarin derivative is first synthesized by linking 5-aminolevulinic acid (5-ALA, the bio-precursor) to coumarin; and the nanosystem (CD-ALA-TPP) is then fabricated by covalently incorporating this coumarin derivative and a mitochondria-targeting compound triphenylphosphonium (TPP) onto carbon dots (CDs)...
February 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Matthew J Budoff, Dong Li, Ella A Kazerooni, Gregory S Thomas, Jennifer H Mieres, Leslee J Shaw
RATIONALE AND OBJECTIVES: Although multiple studies have shown excellent accuracy statistics for noninvasive angiography by coronary computed tomographic angiography (CCTA), most studies comparing nuclear imaging to CCTA were performed on patients already referred for cardiac catheterization, introducing referral and selection bias. This prospective trial evaluated the diagnostic accuracy of 64-row CCTA to detect obstructive coronary stenosis compared to myocardial perfusion imaging (MPI), using quantitative coronary angiography (QCA) as a reference standard...
October 19, 2016: Academic Radiology
Vincenzo Amendola, Stefano Scaramuzza, Francesco Carraro, Elti Cattaruzza
Laser ablation in liquids (LAL) emerged as a powerful technique for the synthesis of multielement nanoparticles (NPs) such as metal alloys with thermodynamically forbidden composition. Consequently, there is a great interest in expanding the current knowledge about NPs formation during LAL, in order to improve the control on product structure and to extend the range of compositions accessible by this technique. Here we performed a systematic investigation on alloy NPs formation by nanosecond LAL of Au/Fe/glass multilayers with different thickness and order of deposition...
October 13, 2016: Journal of Colloid and Interface Science
Claure N Lunardi, Anderson J Gomes, Sandeep Palepu, P Thilanka Galwaduge, Elizabeth M C Hillman
Here we present the production, characterization and in-vivo assessment of cresyl violet-loaded biodegradable PLGA nano/microparticles (CV-NP and CV-MP). We demonstrate that the beneficial spectral characteristics of cresyl violet make it suitable as a tracer for particle-based drug delivery using both hyperspectral wide field and two-photon excited fluorescence microscopy. Particles were prepared using a cosolvent method, after which the physicochemical properties such as morphology, particle size, drug entrapment efficiency, drug loading and in vitro drug release behavior were measured in addition to spectroscopic properties, such as absorption, fluorescence and infrared spectra...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
J S Rojas-Arias, B A Rodríguez, H Vinck-Posada
Dipolaritons are quasiparticles that arise in coupled quantum wells embedded in a microcavity, they are a superposition of a photon, a direct exciton and an indirect exciton. We propose the existence of dipolaritons in a system of two coupled quantum dots inside a microcavity in direct analogy with the quantum well case and find that, despite some similarities, dipolaritons in quantum dots have different properties and can lead to true dark polariton states. We use a finite system theory to study the effects of the magnetic field on the system, including the emission, and find that it can be used as a control parameter of the properties of excitons and dipolaritons, and the overall magnetic behaviour of the structure...
October 21, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
A W Carr, M Saffman
We analyze doubly magic trapping of Cs hyperfine transitions including previously neglected contributions from the ground state hyperpolarizability and the interaction of the laser light and a static magnetic field. Extensive numerical searches do not reveal any doubly magic trapping conditions for any pair of hyperfine states. However, including the hyperpolarizability reveals light intensity insensitive traps for a wide range of wavelengths at specific intensities. We then investigate the use of bichromatic trapping light fields...
October 7, 2016: Physical Review Letters
Daniel Jaeger, Christian Pilger, Henning Hachmeister, Elina Oberländer, Robin Wördenweber, Julian Wichmann, Jan H Mussgnug, Thomas Huser, Olaf Kruse
Oleaginous photosynthetic microalgae hold great promise as non-food feedstocks for the sustainable production of bio-commodities. The algal lipid quality can be analysed by Raman micro-spectroscopy, and the lipid content can be imaged in vivo in a label-free and non-destructive manner by coherent anti-Stokes Raman scattering (CARS) microscopy. In this study, both techniques were applied to the oleaginous microalga Monoraphidium neglectum, a biotechnologically promising microalga resistant to commonly applied lipid staining techniques...
October 21, 2016: Scientific Reports
Mutlu Mete, Unal Sakoglu, Jeffrey S Spence, Michael D Devous, Thomas S Harris, Bryon Adinoff
BACKGROUND: Neuroimaging studies have yielded significant advances in the understanding of neural processes relevant to the development and persistence of addiction. However, these advances have not explored extensively for diagnostic accuracy in human subjects. The aim of this study was to develop a statistical approach, using a machine learning framework, to correctly classify brain images of cocaine-dependent participants and healthy controls. In this study, a framework suitable for educing potential brain regions that differed between the two groups was developed and implemented...
October 6, 2016: BMC Bioinformatics
Aram Hong, Heeseon Jang, Changseop Jeong, Myoung Choul Choi, Jiyoung Heo, Nam Joon Kim
We obtained resonant two-photon ionization circular dichroism (R2PICD) spectra of jet-cooled phenylalanine (Phe) and its hydrated clusters (Phe(H2O)n, n=1-2) near the origin band of the S0-S1 transition. The R2PICD spectra of Phe exhibit well-resolved CD bands of six different conformers present in the jet, which vary in sign and magnitude depending on their conformations. We revised the previous structural assignments of the Phe conformers based on the comparison between the experimental and theoretical CD signs, infrared spectra, and rotational band contours...
October 21, 2016: Journal of Physical Chemistry Letters
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