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https://www.readbyqxmd.com/read/29161502/polarization-multiplexing-of-fluorescent-emission-using-multi-resonant-plasmonic-antennas
#1
Eva De Leo, Ario Cocina, Preksha Tiwari, Lisa V Poulikakos, Patricia Marqués-Gallego, Boris leFeber, David J Norris, Ferry Prins
Combining the ability to localize electromagnetic fields at the nanoscale with a directional response, plasmonic antennas offer an effective strategy to shape the far-field pattern of coupled emitters. Here, we introduce a family of directional multi-resonant antennas that allows for polarization-resolved spectral identification of fluorescent emission. The geometry consists of a central aperture surrounded by concentric polygonal corrugations. By varying the periodicity of each axis of the polygon individually, this structure can support multiple resonances that provide independent control over emission directionality for multiple wavelengths...
November 21, 2017: ACS Nano
https://www.readbyqxmd.com/read/29160832/first-spaceborne-sar-gmti-experimental-results-for-the-chinese-gaofen-3-dual-channel-sar-sensor
#2
Chenghao Wang, Guisheng Liao, Qingjun Zhang
In spaceborne synthetic aperture radar (SAR) sensors, it is a challenging task to detect ground slow-moving targets against strong clutter background with limited spatial channels and restricted pulse repetition frequency (PRF). In this paper, we evaluate the image-based dual-channel SAR-ground moving target indication (SAR-GMTI) workflow for the Gaofen-3 SAR sensor and analyze the impact of strong azimuth ambiguities on GMTI when the displaced phase center antenna (DPCA) condition is not fully satisfied, which has not been demonstrated yet...
November 21, 2017: Sensors
https://www.readbyqxmd.com/read/29160773/rationalizing-substituent-effects-in-1-azathioxanthone-photophysics
#3
Anne Kathrine R Junker, Thomas Just Sørensen
The influence of an electron donating substituent on the photophysical properties of 1-azathioxanthone dyes has been investigated using optical spectroscopy and theoretical models. The motivation behind the study is based on the fact that thioxanthones are efficient triplet sensitizers, and thus promising sensitizers for lanthanide centered emission. By adding an aza group to one of the phenyl ring systems, direct coordination to a lanthanide center becomes possible, which makes azathoixanthones great candidates as antenna chromophores in lanthanide(III) based dyes...
November 21, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/29160220/immune-status-of-the-spiny-lobster-jasus-edwardsii-with-tail-fan-necrosis
#4
Hua Zha, Gillian Lewis, Andrea Alfaro, Shuqi Wang, Yimin Dong, Roffi Grandiosa, Andrew Jeffs
Tail fan necrosis (TFN), a disorder commonly found in some populations of commercially fished and cultured lobsters, is thought to be initiated by injuries caused by handling and containment. The unsightly appearance of affected lobster tails significantly lowers their commercial value. Knowledge about TFN is limited. In this study we describe the morphological features of TFN and apply 6 common methods for evaluating the immune status of wild-caught Australasian red spiny lobsters Jasus edwardsii with and without TFN...
November 21, 2017: Diseases of Aquatic Organisms
https://www.readbyqxmd.com/read/29158602/radiative-control-of-dark-excitons-at-room-temperature-by-nano-optical-antenna-tip-purcell-effect
#5
Kyoung-Duck Park, Tao Jiang, Genevieve Clark, Xiaodong Xu, Markus B Raschke
Excitons, Coulomb-bound electron-hole pairs, are elementary photo-excitations in semiconductors that can couple to light through radiative relaxation. In contrast, dark excitons (XD) show anti-parallel spin configuration with generally forbidden radiative emission. Because of their long lifetimes, these dark excitons are appealing candidates for quantum computing and optoelectronics. However, optical read-out and control of XD states has remained challenging due to their decoupling from light. Here, we present a tip-enhanced nano-optical approach to induce, switch and programmably modulate the XD emission at room temperature...
November 20, 2017: Nature Nanotechnology
https://www.readbyqxmd.com/read/29157260/high-resolution-and-accelerated-multi-parametric-mapping-with-automated-characterization-of-vessel-disease-using-intravascular-mri
#6
Guan Wang, Yi Zhang, Shashank Sathyanarayana Hegde, Paul A Bottomley
BACKGROUND: Atherosclerosis is prevalent in cardiovascular disease, but present imaging modalities have limited capabilities for characterizing lesion stage, progression and response to intervention. This study tests whether intravascular magnetic resonance imaging (IVMRI) measures of relaxation times (T1, T2) and proton density (PD) in a clinical 3 Tesla scanner could characterize vessel disease, and evaluates a practical strategy for accelerated quantification. METHODS: IVMRI was performed in fresh human artery segments and swine vessels in vivo, using fast multi-parametric sequences, 1-2 mm diameter loopless antennae and 200-300 μm resolution...
November 20, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/29156654/a-dual-band-frequency-reconfigurable-origami-magic-cube-antenna-for-wireless-sensor-network-applications
#7
Syed Imran Hussain Shah, Sungjoon Lim
In this paper, a novel dual band frequency reconfigurable antenna using an origami magic cube is proposed for wireless sensor network (WSN) applications. The proposed origami antenna consists of a meandered monopole folded onto three sides of the magic cube. A microstrip open-ended stub is loaded on the meandered monopole. The proposed origami magic cube can be mechanically folded and unfolded. The proposed antenna operates at 1.57 GHZ and 2.4 GHz in the folded state. In the unfolded state, the proposed antenna operates at 900 MHz and 2...
November 20, 2017: Sensors
https://www.readbyqxmd.com/read/29156565/survey-on-the-performance-of-source-localization-algorithms
#8
José Manuel Fresno, Guillermo Robles, Juan Manuel Martínez-Tarifa, Brian G Stewart
The localization of emitters using an array of sensors or antennas is a prevalent issue approached in several applications. There exist different techniques for source localization, which can be classified into multilateration, received signal strength (RSS) and proximity methods. The performance of multilateration techniques relies on measured time variables: the time of flight (ToF) of the emission from the emitter to the sensor, the time differences of arrival (TDoA) of the emission between sensors and the pseudo-time of flight (pToF) of the emission to the sensors...
November 18, 2017: Sensors
https://www.readbyqxmd.com/read/29155558/correlated-absorption-and-scattering-spectroscopy-of-individual-pt-decorated-au-nanorods-reveals-strong-excitation-enhancement-in-the-non-plasmonic-metal
#9
Anneli Joplin, Seyyed Ali Hosseini Jebeli, Eric Sung, Nathan Diemler, Patrick J Straney, Mustafa Yorulmaz, Wei-Shun Chang, Jill E Millstone, Stephan Link
Bimetallic nanocatalysts have the potential to surmount current limitations in industrial catalysis if their electronic and optical properties can be effectively controlled. However, improving the performance of bimetallic photocatalysts requires a functional understanding of how the intricacies of their morphology and composition dictate every element of their optical response. In this work, we examine Au and Pt-decorated Au nanorods on a single particle level to ascertain how Pt influences the plasmon resonance of the bimetallic nanostructure...
November 20, 2017: ACS Nano
https://www.readbyqxmd.com/read/29154855/identification-and-characterization-of-a-calcium-dependent-lily-type-lectin-from-black-rockfish-sebastes-schlegelii-molecular-antennas-are-involved-in-host-defense-via-pathogen-recognition
#10
Roopasingam Kugapreethan, Qiang Wan, Jehanathan Nilojan, Jehee Lee
Lily-type lectins (LTLs) are soluble pathogen recognition receptors (PRRs) that contain one or more characteristic carbohydrate recognition domains (CRDs), through which LTLs bind reversibly and specifically to cognate sugar moieties present on the invading pathogen membrane and trigger the host innate immune responses. In this study, we identified a LTL homolog (SsLTL) from black rockfish (Sebastes schlegelii) transcriptome database and its functional roles in innate immunity was investigated in vitro and in vivo...
November 14, 2017: Developmental and Comparative Immunology
https://www.readbyqxmd.com/read/29151606/a-spectroscopic-survey-of-orion-kl-between-41-5-and-50-ghz
#11
J R Rizzo, B Tercero, J Cernicharo
Context: The nearby massive star-forming region Orion KL is one of the richest molecular reservoirs known in our Galaxy. The region hosts newly formed protostars, and the strong interaction between their radiation and their outflows with the environment results in a series of complex chemical processes leading to a high diversity of interstellar tracers. The region is therefore one of the most frequently observed sources, and the site where many molecular species have been discovered for the first time...
September 2017: Astronomy and Astrophysics
https://www.readbyqxmd.com/read/29151177/mechanisms-of-drought-induced-dissipation-of-excitation-energy-in-sun-and-shade-adapted-drought-tolerant-mosses-studied-by-fluorescence-yield-change-and-global-and-target-analysis-of-fluorescence-decay-kinetics
#12
Hisanori Yamakawa, Ivo H M van Stokkum, Ulrich Heber, Shigeru Itoh
Some mosses stay green and survive long even under desiccation. Dissipation mechanisms of excess excitation energy were studied in two drought-tolerant moss species adapted to contrasting niches: shade-adapted Rhytidiadelphus squarrosus and sun-adapted Rhytidium rugosum in the same family. (1) Under wet conditions, a light-induced nonphotochemical quenching (NPQ) mechanism decreased the yield of photosystem II (PSII) fluorescence in both species. The NPQ extent saturated at a lower illumination intensity in R...
November 18, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/29148805/near-infrared-quantum-dot-emission-enhanced-by-stabilized-self-assembled-j-aggregate-antennas
#13
Francesca S Freyria, José M Cordero, Justin R Caram, Sandra Doria, Amro Dodin, Yue Chen, Adam P Willard, Moungi G Bawendi
Enhancing photoluminescent emission (PL) in the near-infrared-infrared (NIR-IR) spectral region has broad applications from solar energy conversion to biological imaging. We show that self-assembled molecular dye J-aggregates (light-harvesting nanotubes, LHNs) can increase the PL emission of NIR PbS quantum dots (QDs) in both liquid and solid media more than 8-fold, promoted primarily by a long-range antenna effect and efficient Förster resonance energy transfer (FRET) from donor to acceptor. To create this composite material and preserve the optical properties of the nanocrystals, we performed an in situ ligand substitution followed by a functionalization reaction using click-chemistry...
November 17, 2017: Nano Letters
https://www.readbyqxmd.com/read/29144729/an-optical-nanoantenna-for-single-molecule-based-detection-of-zika-virus-nucleic-acids-without-molecular-multiplication
#14
Sarah Elisabeth Ochmann, Carolin Vietz, Kateryna Trofymchuk, Guillermo P Acuna, Birka Lalkens, Philip Tinnefeld
Due to the limited signal-to-background ratio, molecular diagnostics requires molecular amplification of the target molecules or molecular signal amplification after target recognition. For direct molecular detection, we demonstrate a purely physical fluorescence enhancement process which can elevate the fluorescence signal of single fluorescent dyes by several orders of magnitude. To this end, DNA origami-based optical antennas with a height of around 125 nm are used, which utilize metallic nanoparticles to create a hotspot where fluorescence signals are enhanced by plasmonic effects...
November 16, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29143352/assessment-of-exposure-to-radio-frequency-electromagnetic-fields-from-smart-utility-meters-in-gb-part-ii-numerical-assessment-of-induced-sar-within-the-human-body
#15
Muhammad R A Qureshi, Yasir Alfadhl, Xiaodong Chen, Azadeh Peyman, Myron Maslanyj, Simon Mann
Human body exposure to radiofrequency electromagnetic waves emitted from smart meters was assessed using various exposure configurations. Specific energy absorption rate distributions were determined using three anatomically realistic human models. Each model was assigned with age- and frequency-dependent dielectric properties representing a collection of age groups. Generalized exposure conditions involving standing and sleeping postures were assessed for a home area network operating at 868 and 2,450 MHz...
November 16, 2017: Bioelectromagnetics
https://www.readbyqxmd.com/read/29141150/all-dielectric-dual-color-pixel-with-subwavelength-resolution
#16
Yusuke Nagasaki, Masafumi Suzuki, Junichi Takahara
An all-dielectric optical antenna supporting Mie resonances enables light confinement below the free-space diffraction limit. The Mie scattering wavelengths of the antenna depend on the structural geometry, which allows the antennas to be used for colored imprint images. However, there is still room for improving the spatial resolution, and new polarization-dependent color functionalities are highly desirable for realizing a wider color tuning range. Here, we show all-dielectric color printing by means of dual-color pixels with a subwavelength-scale resolution...
November 15, 2017: Nano Letters
https://www.readbyqxmd.com/read/29140313/a-new-low-complexity-angle-of-arrival-algorithm-for-1d-and-2d-direction-estimation-in-mimo-smart-antenna-systems
#17
Mohammed A G Al-Sadoon, Nazar T Ali, Yousf Dama, Abdulkareim Zuid, Stephen M R Jones, Raed A Abd-Alhameed, James M Noras
This paper proposes a new low complexity angle of arrival (AOA) method for signal direction estimation in multi-element smart wireless communication systems. The new method estimates the AOAs of the received signals directly from the received signals with significantly reduced complexity since it does not need to construct the correlation matrix, invert the matrix or apply eigen-decomposition, which are computationally expensive. A mathematical model of the proposed method is illustrated and then verified using extensive computer simulations...
November 15, 2017: Sensors
https://www.readbyqxmd.com/read/29137991/spectrally-decomposed-dark-to-light-transitions-in-a-psi-deficient-mutant-of-synechocystis-sp-pcc-6803
#18
Alonso M Acuña, Pascal van Alphen, Filipe Branco Dos Santos, Rienk van Grondelle, Klaas J Hellingwerf, Ivo H M van Stokkum
Cyanobacterial thylakoid membranes are known to host photosynthetic and respiratory complexes. This hampers a straight forward interpretation of the highly dynamic fluorescence originating from photosynthetic units. The present study focuses on dark-to-light transitions in whole cells of a PSI-deficient mutant of the cyanobacterium Synechocystis sp. PCC 6803. The time-dependent cellular fluorescence spectrum has been measured, while having previously exposed the cells to different conditions that affect respiratory activity...
November 11, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29136458/deficiency-of-the-stroma-lamellar-protein-lil8-psb33-affects-energy-transfer-around-psi-in-arabidopsis
#19
Yukako Kato, Makio Yokono, Seiji Akimoto, Atsushi Takabayashi, Ayumi Tanaka, Ryouichi Tanaka
Light-harvesting-like (LIL) proteins are a group of proteins that share a consensus amino acid sequence with light-harvesting Chl-binding (LHC) proteins. We hypothesized that they might be involved in photosynthesis-related processes. In order to gain a better understanding of a potential role in photosynthesis-related processes, we examined the most recently identified LIL protein, LIL8/PSB33. Recently, it was suggested that this protein is an auxiliary PSII core protein which is involved in organization of the PSII supercomplex...
November 1, 2017: Plant & Cell Physiology
https://www.readbyqxmd.com/read/29134022/larva-and-pupa-of-megatoma-s-str-undata-linnaeus-1758-with-remarks-on-biology-and-economic-importance-coleoptera-dermestidae
#20
Marcin Kadej
An updated description of the final larval instar and pupa of Megatoma (s. str.) undata (Linnaeus, 1758) (Coleoptera: Dermestidae) is presented. Several morphological characteristics of M. undata larvae are documented and discussed: antenna, epipharynx, mandibula, maxilla, ligula with labial palpi, hastisetae, terga, and condition of the antecostal suture. The paper is fully illustrated and includes some important additions to extend notes on this species available in the references. Summarised data about biology, economic importance, and distribution of M...
2017: ZooKeys
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