keyword
MENU ▼
Read by QxMD icon Read
search

Optical

keyword
https://www.readbyqxmd.com/read/28239860/hypovitaminosis-a-in-extensively-grazed-beef-cattle
#1
E M Parker, C P Gardiner, A E Kessell, A J Parker
CASE REPORT: Vitamin A deficiency was diagnosed in a herd of 97 19-month-old Braford heifers in the Mitchell Grass Downs (Astrebla spp.) bioregion of Hughenden in north-western Queensland during November 2015. Two heifers died after a 48-h history of sternal recumbency and of the 19 that had neurological signs, 7 were blind. Histological changes in the optic nerves of the two necropsied cattle were consistent with vitamin A deficiency. This diagnosis was supported by vitamin A concentrations in fresh liver samples of 5 and 6 mg/kg wet tissue (reference range, 100-175 mg/kg) despite treatment of the cattle with twice the recommended dose of parenteral vitamin A 3 weeks prior to sampling...
March 2017: Australian Veterinary Journal
https://www.readbyqxmd.com/read/28239829/comparison-of-anterior-segment-parameter-values-obtained-with-scheimpflug-placido-topographer-optical-low-coherence-reflectometry-and-noncontact-specular-microscopy-in-morbid-obesity
#2
B Dogan, U Dogan, M K Erol, M Habibi, M T Oruc
OBJECTIVE: To investigate the measurement of anterior segment parameters using Sirius Scheimpflug-Placido topographer, Lenstar optical low coherence reflectometry (OLCR), and noncontact specular microscopy (SM) in morbidly obese and nonobese subjects. PATIENTS AND METHODS: Twenty-eight morbidly obese subjects (BMI ≥ 40; Group 1) and 28 age- sex-matched healthy nonobese subjects (BMI 18.50-24.99; Group 2) were included in this study. Anterior segment parameters were measured by Scheimpflug-Placido topographer and OLCR...
February 2017: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/28239828/the-relation-of-the-serum-aldosterone-level-and-central-serous-chorioretinopathy-a-pilot-study
#3
Q Gong, X-H Sun, S-T Yuan, Q-H Liu
OBJECTIVE: The aim of this study was to investigate the serum aldosterone level and abnormal levels of mineral corticoid in patients with the central serous chorioretinopathy (CSC). PATIENTS AND METHODS: All recruited patients with CSC received fundus fluorescein angiography (FFA), enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) and serum aldosterone assay. The patients were classified into spontaneously resolved group and unresolved group according to a 3-months follow-up of Optical Coherence Tomography (OCT) examination...
February 2017: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/28239736/ferrocene-diketopyrrolopyrrole-based-small-molecule-donors-for-bulk-heterojunction-solar-cells
#4
Yuvraj Patil, Rajneesh Misra, Manish Kumar Singh, Ganesh D Sharma
A symmetrical D-π-A-π-D type small molecule consisting of thiophene flanked diketopyrrolopyrrole (DPP) as a core and an end capping ferrocene donor linked by an ethynyl bridge, denoted as Fc-DPP-Fc, was synthesized and its optical, thermal and electrochemical properties were investigated in order to explore its potential applicability as a donor for solution processed bulk heterojunction solar cells. The photophysical and electrochemical properties of this small molecule showed strong charge transfer interaction between the ferrocene donor and the DPP acceptor, and it is found to be suitable as a small molecule donor along with PC71BM as an electron acceptor for solution processed bulk heterojunction organic solar cells (OSCs)...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239718/solvent-control-of-intramolecular-proton-transfer-is-4-hydroxy-3-piperidin-1-ylmethyl-1-naphthaldehyde-a-proton-crane
#5
Y Manolova, H Marciniak, S Tschierlei, F Fennel, F S Kamounah, S Lochbrunner, L Antonov
The solvent dependent excited state dynamics of 4-hydroxy-3-(piperidin-1-ylmethyl)-1-naphthaldehyde (compound 2), a candidate for a molecular switch based on intramolecular proton transfer, was investigated by ultrafast spectroscopy and quantum-chemical calculations. In acetonitrile a mixture of molecules in the enol and zwitterionic proton transfer (PT) form exists in the ground state. However, the zwitterion is the energetically favored one in the electronically excited state. Optical excitation of the enol form results in intramolecular proton transfer and formation of the PT form within 1...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239716/h-bonding-controls-the-emission-properties-of-functionalized-carbon-nano-dots
#6
Soumalya Mukherjee, Edamana Prasad, Anju Chadha
Bathochromic and hypsochromic shifts in the photo-luminescent spectra of doped and functionalized carbon nano-dots (CDs) arise due to the complex interaction between CDs and the solvent molecules around them. Nitrogen-functionalized carbon nano-dots (N-CDs) were synthesized from citric acid and urea using microwave assisted hydrothermal methods. Optical studies (absorption and photoluminescence) from the as-synthesized N-CDs were carried out in polar protic, aprotic and non-polar solvents. When excited at 355 nm, blue photoluminescence (PL) was observed from the N-CDs dispersed in polar aprotic solvents while green emission was observed in polar protic solvents...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239707/optically-probing-the-localized-to-delocalized-transition-in-mo2-mo2-mixed-valence-systems
#7
Yi Yang Wu, Miao Meng, Gang Yi Wang, Pengju Feng, Chun Y Liu
Four thienylene (C4H2S) bridged Mo2 dimers, [Mo2(DAniF)3]2(μ-OOCC4H2SCOO) (DAniF = N,N'-di(p-anisyl)formamidinate), [Mo2(DAniF)3]2(μ-N(H)SCC4H2SCN(H)S), [Mo2(DAniF)3]2(μ-OSCC4H2SCSO) and [Mo2(DAniF)3]2(μ-SSCC4H2SCSS), have been synthesized and studied in terms of electronic coupling. The subtle structural differences between these compounds vary largely the extent of electron delocalization; consequently, a systematic transition from Class II to Class III via Class II-III is achieved, which is probed using spectral parameters of intervalence charge transfer (IVCT) absorption (band energy, intensity and shape) for the mixed-valence complexes...
February 27, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28239697/optimization-of-highly-sensitive-yag-cr-3-nd-3-nanocrystal-based-luminescent-thermometer-operating-in-an-optical-window-of-biological-tissues
#8
L Marciniak, A Bednarkiewicz, J Drabik, K Trejgis, W Strek
Luminescent and temperature sensitive properties of YAG:Cr(3+),Nd(3+) nanocrystals were analyzed as a function of temperature, nanoparticle size, and excitation wavelength. Due to numerous temperature-dependent phenomena (e.g. Boltzmann population, thermal quenching, and inter-ion energy transfer) occurring in this phosphor, four different thermometer definitions were evaluated with the target to achieve a high sensitivity and broad temperature sensitivity range. Using a Cr(3+) to Nd(3+) emission intensity ratio, the highest 3...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239670/influence-of-acidic-ph-on-the-formulation-of-tio2-nanocrystalline-powders-with-enhanced-photoluminescence-property
#9
Moges Tsega, F B Dejene
Titanium dioxide (TiO2) nanoparticles were prepared by the sol-gel method at different pH values (3.2-6.8) with a hydrochloric acid (HCl) solution. Raw samples were calcined at 500 °C for 2 h. The effects of pH on the structural, morphological and optical properties of TiO2 nanoparticles were investigated. At pH 4.4-6.8, only the anatase phase of TiO2 was observed. Under strong acidic condition at pH 3.2 rutile, brookite and anatase co-exist, but rutile is the predominant phase. The strain value increased and the crystallite size decreased as the HCl content increased...
February 2017: Heliyon
https://www.readbyqxmd.com/read/28239628/cubic-meter-volume-optical-coherence-tomography
#10
Zhao Wang, Benjamin Potsaid, Long Chen, Chris Doerr, Hsiang-Chieh Lee, Torben Nielson, Vijaysekhar Jayaraman, Alex E Cable, Eric Swanson, James G Fujimoto
Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 µm depth resolution for tomographic imaging at a 100 kHz axial scan rate over a 1...
December 2016: Optica
https://www.readbyqxmd.com/read/28239617/analytic-optimization-of-near-field-optical-chirality-enhancement
#11
Christian Kramer, Martin Schäferling, Thomas Weiss, Harald Giessen, Tobias Brixner
We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an achiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular...
February 15, 2017: ACS Photonics
https://www.readbyqxmd.com/read/28239616/optimization-of-nanoparticle-based-sers-substrates-through-large-scale-realistic-simulations
#12
Diego M Solís, José M Taboada, Fernando Obelleiro, Luis M Liz-Marzán, F Javier García de Abajo
Surface-enhanced Raman scattering (SERS) has become a widely used spectroscopic technique for chemical identification, providing unbeaten sensitivity down to the single-molecule level. The amplification of the optical near field produced by collective electron excitations -plasmons- in nanostructured metal surfaces gives rise to a dramatic increase by many orders of magnitude in the Raman scattering intensities from neighboring molecules. This effect strongly depends on the detailed geometry and composition of the plasmon-supporting metallic structures...
February 15, 2017: ACS Photonics
https://www.readbyqxmd.com/read/28239587/manoeuvres-to-improve-endoscopic-visualization-of-hypopharynx
#13
Pooja Thakur, V K Poorey
The more progress achieved in endoscopy, the more superficial cancers in head and neck region have been diagnosed. There are, however, some areas difficult to observe, particularly the hypopharynx, due to closure of this space. Examination of hypopharynx form an essential part of head and neck examination especially in the suspected malignancies as well as in the cases with unknown primary. As the flexible fiber-optic nasopharyngolaryngoscopy forms an essential part of examination of hypopharynx, the present study aims to evaluate the effectiveness of various manoeuvres devised to aid in better visualization of the hypopharynx...
March 2017: Indian Journal of Otolaryngology and Head and Neck Surgery
https://www.readbyqxmd.com/read/28239552/fiber-optic-annular-detector-array-for-large-depth-of-field-photoacoustic-macroscopy
#14
Johannes Bauer-Marschallinger, Astrid Höllinger, Bernhard Jakoby, Peter Burgholzer, Thomas Berer
We report on a novel imaging system for large depth of field photoacoustic scanning macroscopy. Instead of commonly used piezoelectric transducers, fiber-optic based ultrasound detection is applied. The optical fibers are shaped into rings and mainly receive ultrasonic signals stemming from the ring symmetry axes. Four concentric fiber-optic rings with varying diameters are used in order to increase the image quality. Imaging artifacts, originating from the off-axis sensitivity of the rings, are reduced by coherence weighting...
March 2017: Photoacoustics
https://www.readbyqxmd.com/read/28239524/pattern-of-gray-matter-volumes-related-to-retinal-thickness-and-its-association-with-cognitive-function-in-relapsing-remitting-ms
#15
Jan-Patrick Stellmann, Hanife Cetin, Kim Lea Young, Sibylle Hodecker, Jana Pöttgen, Diana Bittersohl, Andrea Hassenstein, Timm Oberwahrenbrock, Christoph Heesen, Susanne Siemonsen
BACKGROUND: Neurodegeneration in multiple sclerosis (MS) may be investigated in the visual system as optical coherence tomography (OCT) and magnetic resonance imaging (MRI) allows examining structural integrity in detail. The association between thickness of retinal layers and focal cortical volumes beyond the primary visual system has not been thoroughly investigated. OBJECTIVE: To investigate the association between focal cortical volume and thickness of retinal layers...
February 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28239477/stimuli-responsive-furan-and-thiophene-substituted-difluoroboron-%C3%AE-diketonate-materials
#16
William A Morris, Tristan Butler, Milena Kolpaczynska, Cassandra L Fraser
Difluoroboron β-diketonate (BF2bdk) compounds exhibit solid-state switchable luminescence under excitation by UV light. This property is usually manifested as a blue-shift in emission when dye films are thermally annealed followed by a red-shift in response to mechanical shear (i.e. mechanochromic luminescence). Here we report thiophene and furan heterocycle-substituted dyes bearing short methoxy and long dodecyloxy chain substituents. Optical properties of the dyes were investigated in solution, pristine powders, and films on paper and glass...
January 1, 2017: Mater Chem Front
https://www.readbyqxmd.com/read/28239431/tuning-localized-surface-plasmon-resonance-wavelengths-of-silver-nanoparticles-by-mechanical-deformation
#17
Fathima S Ameer, Shilpa Varahagiri, Donald W Benza, Daniel R Willett, Yimei Wen, Fenglin Wang, George Chumanov, Jeffrey N Anker
We describe a simple technique to alter the shape of silver nanoparticles (AgNPs) by rolling a glass tube over them to mechanically compress them. The resulting shape change in turn induces a red-shift in the localized surface plasmon resonance (LSPR) scattering spectrum and exposes new surface area. The flattened particles were characterized by optical and electron microscopy, single nanoparticle scattering spectroscopy, and surface enhanced Raman spectroscopy (SERS). AFM and SEM images show that the AgNPs deform into discs; increasing the applied load from 0 to 100 N increases the AgNP diameter and decreases the height...
September 22, 2016: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/28239411/reliable-measurement-of-e-coli-single-cell-fluorescence-distribution-using-a-standard-microscope-set-up
#18
Marilisa Cortesi, Lucia Bandiera, Alice Pasini, Alessandro Bevilacqua, Alessandro Gherardi, Simone Furini, Emanuele Giordano
BACKGROUND: Quantifying gene expression at single cell level is fundamental for the complete characterization of synthetic gene circuits, due to the significant impact of noise and inter-cellular variability on the system's functionality. Commercial set-ups that allow the acquisition of fluorescent signal at single cell level (flow cytometers or quantitative microscopes) are expensive apparatuses that are hardly affordable by small laboratories. METHODS: A protocol that makes a standard optical microscope able to acquire quantitative, single cell, fluorescent data from a bacterial population transformed with synthetic gene circuitry is presented...
2017: Journal of Biological Engineering
https://www.readbyqxmd.com/read/28239352/celastrol-attenuates-multiple-sclerosis-and-optic-neuritis-in-an-experimental-autoimmune-encephalomyelitis-model
#19
Hongbin Yang, Chang Liu, Jie Jiang, Yuena Wang, Xiaoyu Zhang
This study was aimed to evaluate the effects of celastrol, a natural compound with multiple bioactivities, on multiple sclerosis and optic neuritis (ON) in rat experimental autoimmune encephalomyelitis (EAE). EAE was induced in Sprague Dawley rats using myelin basic protein, and the animals received daily intraperitoneal injections of celastrol or vehicle for 13 days. The EAE rats showed abnormal neurobehavior and inflammatory infiltration and demyelination in the spinal cord. Significantly upregulated mRNA expression of pro-inflammatory cytokines interferon-γ and interleukin-17 and downregulated anti-inflammatory cytokines interleukin-4 were found in the spinal cord of EAE rats...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28239332/characterization-of-the-circumlimbal-suture-model-of-chronic-iop-elevation-in-mice-and-assessment-of-changes-in-gene-expression-of-stretch-sensitive-channels
#20
Da Zhao, Christine T O Nguyen, Vickie H Y Wong, Jeremiah K H Lim, Zheng He, Andrew I Jobling, Erica L Fletcher, Holly R Chinnery, Algis J Vingrys, Bang V Bui
To consider whether a circumlimbal suture can be used to chronically elevate intraocular pressure (IOP) in mice and to assess its effect on retinal structure, function and gene expression of stretch sensitive channels. Anesthetized adult C57BL6/J mice had a circumlimbal suture (10/0) applied around the equator of one eye. In treated eyes (n = 23) the suture was left in place for 12 weeks whilst in sham control eyes the suture was removed at day two (n = 17). Contralateral eyes served as untreated controls. IOP was measured after surgery and once a week thereafter...
2017: Frontiers in Neuroscience
keyword
keyword
5606
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"