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https://www.readbyqxmd.com/read/28531846/synthesis-characterization-and-nonlinear-optical-nlo-properties-of-truxene-cored-diphenylamine-derivatives
#1
Fusheng Li, Baodong Zhao, Yu Chen, Yufei Zhang, Tao Wang, Song Xue
Three star-shaped compounds based on a truxene core (FS11, FS12 and FS13) were prepared. The truxene core is incorporating with asymmetric diphenylamines, including one phenyl of diphenylamine substituted by methoxy group and the other phenyl substituted by tolyl, fluorophenyl and phenylethynyl for FS11, FS12 and FS13, respectively. Their one-photon, two-photon absorption, geometric structures, electrochemical behavior and thermal properties were investigated. The absorption maxima of charge transfer band for FS11, FS12 and FS13 are 375nm, 373nm and 383nm, and the corresponding molar extinction coefficients of FS11, FS12 and FS13 is 79,950M(-1)cm(-1), 67,220M(-1)cm(-1) and 108,780M(-1)cm(-1)...
May 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28531193/raman-microscopy-investigation-of-vitrification-induced-structural-damages-in-mature-bovine-oocytes
#2
Giulia Rusciano, Carolina De Canditiis, Gianluigi Zito, Marcello Rubessa, Maria Serena Roca, Rosa Carotenuto, Antonio Sasso, Bianca Gasparrini
Although oocyte cryopreservation has great potentials in the field of reproductive technologies, it still is an open challenge in the majority of domestic animals and little is known on the biochemical transformation induced by this process in the different cellular compartments. Raman micro-spectroscopy allows the non-invasive evaluation of the molecular composition of cells, based on the inelastic scattering of laser photons by vibrating molecules. The aim of this work was to assess the biochemical modifications of both the zona pellucida and cytoplasm of vitrified/warmed in vitro matured bovine oocytes at different post-warming times...
2017: PloS One
https://www.readbyqxmd.com/read/28531093/development-of-a-low-energy-x-ray-camera-for-the-imaging-of-secondary-electron-bremsstrahlung-x-ray-emitted-during-proton-irradiation-for-range-estimation
#3
Koki Ando, Mitsutaka Yamaguchi, Seiichi Yamamoto, Toshiyuki Toshito, Naoki Kawachi
Imaging of secondary electron bremsstrahlung x-ray emitted during proton irradiation is a possible method for measurement of the proton beam distribution in phantom. However, it is not clear that the method is used for range estimation of protons. For this purpose, we developed a low-energy x-ray camera and conducted imaging of the bremsstrahlung x-ray produced during irradiation of proton beams. We used a 20 mm  ×  20 mm  ×  1 mm finely grooved GAGG scintillator that was optically coupled to a one-inch square high quantum efficiency (HQE)-type position-sensitive photomultiplier tube to form an imaging detector...
May 22, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28531089/au-nanoparticle-decorated-silicon-pyramids-for-plasmon-enhanced-hot-electron-near-infrared-photodetection
#4
Zhiyang Qi, Yusheng Zhai, Long Wen, Qilong Wang, Qin Chen, Sami Iqbal, Guangdian Chen, Ji Xu, Yan Tu
Heterojunction between metal and silicon (Si) is an attractive route to extend the response of Si-based photodiodes into the near-infrared (NIR) region, so-called Schottky barrier diodes. Photons absorbed into a metallic nanostructure excite the surface plasmon resonances (SPRs), which can be damped non-radiatively through the creation of hot electrons. Unfortunately, quantum efficiency of hot electron detectors remains low due to low optical absorption and poor electron injection efficiency. In this study, we propose an efficient and low-cost plasmonic hot electron NIR photodetector based on Au nanoparticle (Au NP)-decorated Si pyramid Schottky junction...
May 22, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28530831/blue-shifted-green-fluorescent-protein-homologs-are-brighter-than-enhanced-green-fluorescent-protein-under-two-photon-excitation
#5
Rosana S Molina, Tam M Tran, Robert E Campbell, Gerard Glenn Lambert, Anya Salih, Nathan C Shaner, Thomas E Hughes, Mikhail Drobizhev
Fluorescent proteins (FPs) are indispensable markers for two-photon imaging of live tissue, especially in the brains of small model organisms. The quantity of physiologically relevant data collected, however, is limited by heat-induced damage of the tissue due to the high intensities of the excitation laser. We seek to minimize this damage by developing FPs with improved brightness. Among FPs with the same chromophore structure, the spectral properties can vary widely due to differences in the local protein environment...
May 22, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28530726/surface-enhanced-hyper-raman-scattering-sehrs-and-its-applications
#6
REVIEW
Fani Madzharova, Zsuzsanna Heiner, Janina Kneipp
Surface enhanced hyper Raman scattering (SEHRS) is the spontaneous, two-photon excited Raman scattering that occurs for molecules residing in high local optical fields of plasmonic nanostructures. Being regarded as a non-linear analogue of surface enhanced Raman scattering (SERS), SEHRS shares most of its properties, but also has additional characteristics. They include complementary spectroscopic information resulting from different selection rules and a stronger enhancement due to the non-linearity in excitation...
May 22, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28530551/angular-velocity-integration-in-a-fly-heading-circuit
#7
Daniel Turner-Evans, Stephanie Wegener, Hervé Rouault, Romain Franconville, Tanya Wolff, Johannes D Seelig, Shaul Druckmann, Vivek Jayaraman
Many animals maintain an internal representation of their heading as they move through their surroundings. Such a compass representation was recently discovered in a neural population in the Drosophila melanogaster central complex, a brain region implicated in spatial navigation. Here, we use two-photon calcium imaging and electrophysiology in head-fixed walking flies to identify a different neural population that conjunctively encodes heading and angular velocity, and is excited selectively by turns in either the clockwise or counterclockwise direction...
May 22, 2017: ELife
https://www.readbyqxmd.com/read/28530280/visualization-of-vesicular-transport-from-the-endoplasmic-reticulum-to-lysosome-using-an-amidine-derived-two-photon-probe
#8
Hyo Won Lee, Myoung Ki Cho, Hye-Ri Kim, Chang Su Lim, Chulhun Kang, Hwan Myung Kim
We report an amidine-based small molecule two-photon fluorescent probe (ELP1) for monitoring vesicle transport from the ER to lysosome in live cells. Two-photon microscopy imaging studies indicated that this probe initially localized in the ER and subsequently transferred to lysosomal compartments through vesicular transport. These results may provide an effective tool for studying trafficking-related biology and pathology in real-time.
May 22, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28530273/single-photon-transient-hot-electron-ionization-of-c60
#9
K Hansen
Recent experiments have demonstrated that C60 can ionize in a thermal process after absorption of a photon with energy far above the ionization energy. This indirect ionization mechanism is investigated here by calculating the total and singly charged ion yields, electron energy distributions, and effective electronic temperatures as a function of photon energy.
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530270/two-photon-photoelectron-emission-microscopy-for-surface-plasmon-polaritons-at-the-au-111-surface-decorated-with-alkanethiolate-self-assembled-monolayers
#10
Kana Yamagiwa, Masahiro Shibuta, Atsushi Nakajima
In this study, we have employed dual-color photoelectron emission microscopy (2P-PEEM) to visualize surface plasmon polaritons (SPPs) propagating along a chemically modified organic/metal interface of alkanethiolate self-assembled monolayers (Cn-SAMs; n is the number of alkyl carbon atoms) formed on Au(111). In dual-color 2P-PEEM, near-infrared photons around 900 nm generate SPPs at the Cn-SAMs/Au(111) interface, which interfere with the remaining light field. The resulting surface polarization beats are imaged as local distributions of 2P-photoelectrons probed by ultraviolet photons...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530249/large-scale-quantum-emitter-arrays-in-atomically-thin-semiconductors
#11
Carmen Palacios-Berraquero, Dhiren M Kara, Alejandro R-P Montblanch, Matteo Barbone, Pawel Latawiec, Duhee Yoon, Anna K Ott, Marko Loncar, Andrea C Ferrari, Mete Atatüre
Quantum light emitters have been observed in atomically thin layers of transition metal dichalcogenides. However, they are found at random locations within the host material and usually in low densities, hindering experiments aiming to investigate this new class of emitters. Here, we create deterministic arrays of hundreds of quantum emitters in tungsten diselenide and tungsten disulphide monolayers, emitting across a range of wavelengths in the visible spectrum (610-680 nm and 740-820 nm), with a greater spectral stability than their randomly occurring counterparts...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28530242/interface-driven-formation-of-a-two-dimensional-dodecagonal-fullerene-quasicrystal
#12
M Paßens, V Caciuc, N Atodiresei, M Feuerbacher, M Moors, R E Dunin-Borkowski, S Blügel, R Waser, S Karthäuser
Since their discovery, quasicrystals have attracted continuous research interest due to their unique structural and physical properties. Recently, it was demonstrated that dodecagonal quasicrystals could be used as bandgap materials in next-generation photonic devices. However, a full understanding of the formation mechanism of quasicrystals is necessary to control their physical properties. Here we report the formation of a two-dimensional dodecagonal fullerene quasicrystal on a Pt3Ti(111) surface, which can be described in terms of a square-triangle tiling...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28530219/deterministic-strain-induced-arrays-of-quantum-emitters-in-a-two-dimensional-semiconductor
#13
Artur Branny, Santosh Kumar, Raphaël Proux, Brian D Gerardot
An outstanding challenge in quantum photonics is scalability, which requires positioning of single quantum emitters in a deterministic fashion. Site positioning progress has been made in established platforms including defects in diamond and self-assembled quantum dots, albeit often with compromised coherence and optical quality. The emergence of single quantum emitters in layered transition metal dichalcogenide semiconductors offers new opportunities to construct a scalable quantum architecture. Here, using nanoscale strain engineering, we deterministically achieve a two-dimensional lattice of quantum emitters in an atomically thin semiconductor...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28530008/field-strength-and-frequency-tunable-two-way-rotation-of-liquid-crystal-micro-particles-dispersed-in-a-liquid-crystal-host
#14
Koki Imamura, Hiroyuki Yoshida, Masanori Ozaki
Liquid crystal (LC) micro-particles are functional materials possessing anisotropies of LCs originating from their inner molecular alignment, and are fabricated by polymerizing pre-aligned rod-like molecules in the LC state. Here we demonstrate field strength and frequency tunable two-way rotation control of LC micro-particles in a LC host, and unravel its mechanism by theoretically calculating the contributing free energies. Cuboid-shaped micro-particles with inner molecular alignment along the long axis are fabricated via two-photon excited direct laser writing, and dispersed in a dual-frequency (DF) LC to be electrically driven by a voltage applied in the in-plane direction of the cell...
May 22, 2017: Soft Matter
https://www.readbyqxmd.com/read/28529673/on-chip-two-photon-metabolic-imaging-for-drug-toxicity-testing
#15
Fang Yu, Shuangmu Zhuo, Yinghua Qu, Deepak Choudhury, Zhiping Wang, Ciprian Iliescu, Hanry Yu
We have developed a microfluidic system suitable to be incorporated with a metabolic imaging method to monitor the drug response of cells cultured on a chip. The cells were perfusion-cultured to mimic the blood flow in vivo. Label-free optical measurements and imaging of nicotinamide adenine dinucleotide and flavin adenine dinucleotide fluorescence intensity and morphological changes were evaluated non-invasively. Drug responses calculated using redox ratio imaging were compared with the drug toxicity testing results obtained with a traditional well-plate system...
May 2017: Biomicrofluidics
https://www.readbyqxmd.com/read/28529642/tumor-triggered-drug-release-from-calcium-carbonate-encapsulated-gold-nanostars-for-near-infrared-photodynamic-photothermal-combination-antitumor-therapy
#16
Yanlei Liu, Xiao Zhi, Meng Yang, Jingpu Zhang, Lingnan Lin, Xin Zhao, Wenxiu Hou, Chunlei Zhang, Qian Zhang, Fei Pan, Gabriel Alfranca, Yuming Yang, Jesús M de la Fuente, Jian Ni, Daxiang Cui
Different stimulus including pH, light and temperature have been used for controlled drug release to prevent drug inactivation and minimize side-effects. Herein a novel nano-platform (GNS@CaCO3/ICG) consisting of calcium carbonate-encapsulated gold nanostars loaded with ICG was established to couple the photothermal properties of gold nanostars (GNSs) and the photodynamic properties of indocyanine green (ICG) in the photodynamic/photothermal combination therapy (PDT/PTT). In this study, the calcium carbonate worked not only a drug keeper to entrap ICG on the surface of GNSs in the form of a stable aggregate which was protected from blood clearance, but also as the a pH-responder to achieve highly effective tumor-triggered drug release locally...
2017: Theranostics
https://www.readbyqxmd.com/read/28528636/correlative-two-photon-and-serial-block-face-scanning-electron-microscopy-in-neuronal-tissue-using-3d-near-infrared-branding-maps
#17
Robert M Lees, Christopher J Peddie, Lucy M Collinson, Michael C Ashby, Paul Verkade
Linking cellular structure and function has always been a key goal of microscopy, but obtaining high resolution spatial and temporal information from the same specimen is a fundamental challenge. Two-photon (2P) microscopy allows imaging deep inside intact tissue, bringing great insight into the structural and functional dynamics of cells in their physiological environment. At the nanoscale, the complex ultrastructure of a cell's environment in tissue can be reconstructed in three dimensions (3D) using serial block face scanning electron microscopy (SBF-SEM)...
2017: Methods in Cell Biology
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
#18
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
#19
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
#20
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
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