keyword
MENU ▼
Read by QxMD icon Read
search

Polarimetry

keyword
https://www.readbyqxmd.com/read/28706282/retinal-degeneration-in-progressive-supranuclear-palsy-measured-by-optical-coherence-tomography-and-scanning-laser-polarimetry
#1
Birthe Stemplewitz, Robert Kromer, Eik Vettorazzi, Ute Hidding, Andreas Frings, Carsten Buhmann
This cross-sectional study compared the retinal morphology between patients with progressive supranuclear palsy (PSP) and healthy controls. (The retinal nerve fiber layer (RNFL) around the optic disc and the retina in the macular area of 22 PSP patients and 151 controls were investigated by spectral domain optical coherence tomography (SD-OCT). Additionally, the RNFL and the nerve fiber index (NFI) were measured by scanning laser polarimetry (SLP). Results of RNFL measurements with SD-OCT and SLP were compared to assess diagnostic discriminatory power...
July 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28684356/sauromatum-guttatum-lectin-spectral-studies-lectin-carbohydrate-interaction-molecular-cloning-and-in-silico-analysis
#2
Kshema Thakur, Tarnjeet Kaur, Jatinder Singh, Gulam Rabbani, Rizwan H Khan, Rachna Hora, Manpreet Kaur
Non-immune carbohydrate binding proteins are broadly defined as lectins. Having been reported from all kingdoms of life, phytolectins are the most widely studied group of lectins. Sauromatum guttatum agglutinin (SGA) was isolated from the plant tubers and characterized for structural variations due to solvent perturbation using polarimetry, fluorescence and light scattering. For the β-sheet rich SGA, a pH and temperature induced molten globule like intermediate was identified. In isothermal titration microcalorimetry, SGA demonstrated cooperative binding to a complex glycoprotein in enthalpically driven mechanism...
July 3, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28682302/precise-characterization-of-self-catalyzed-iii-v-nanowire-heterostructures-via-optical-second-harmonic-generation
#3
Ying Yu, Jing Wang, Yuming Wei, Zhangkai Zhou, Haiqiao Ni, Zhichuan Niu, Xuehua Wang, Siyuan Yu
We demonstrate the utility of optical second harmonic generation (SHG) polarimetry to perform structural characterization of self-assembled zinc-blende/wurtzite III-V nanowire heterostructures. By analyzing four anisotropic SHG polarimetric patterns, we distinguish between wurtzite (WZ), zinc-blende (ZB) and ZB/WZ mixing III-V semiconducting crystal structures in nanowire systems. By neglecting the surface contributions and treating the bulk crystal within the quasi-static approximation, we can well explain the optical SHG polarimetry from the NWs with diameter from 200 to 600 nm...
July 6, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28676874/chiroptical-properties-of-cryptophane-111
#4
Thierry Buffeteau, Delphine Pitrat, Nicolas Daugey, Nathalie Calin, Marion Jean, Nicolas Vanthuyne, Laurent Ducasse, Frank Wien, Thierry Brotin
The two enantiomers of cryptophane-111 (1), which possesses the most simplified chemical structure of cryptophane derivatives and exhibits the highest binding constant for xenon encapsulation in organic solution, were separated by HPLC using chiral stationary phases. The chiroptical properties of [CD(+)254]-1 and [CD(-)254]-1 were determined in CH2Cl2 and CHCl3 solutions by polarimetry, electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) experiments and were compared to those of cryptophane-222 (2) derivative...
July 5, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28652701/follow-up-of-the-retinal-nerve-fiber-layer-thickness-of-diabetic-patients-type-2-as-a-predisposing-factor-for-glaucoma-compared-to-normal-subjects
#5
Alexandros Takis, Dimitrios Alonistiotis, Nikolaos Ioannou, Evgenia Kontou, Maria Mitsopoulou, Dimitrios Papaconstantinou
PURPOSE: To evaluate and follow-up the retinal nerve fiber layer (RNFL) thickness in patients with diabetes mellitus type 2 compared to a group of healthy individuals with similar demographic characteristics. PATIENTS AND METHODS: This is a prospective, noninvasive, observational case series study. For the purposes of the study, 27 eyes of diabetic patients without diabetic retinopathy, 24 eyes of patients with mild retinopathy, and 25 normal age-matched subjects (control group [CG]) were examined...
2017: Clinical Ophthalmology
https://www.readbyqxmd.com/read/28624539/polarization-resolved-second-harmonic-microscopy
#6
REVIEW
Nirmal Mazumder, Gitanjal Deka, Wei-Wen Wu, Ankur Gogoi, Guan-Yu Zhuo, Fu-Jen Kao
Second harmonic (SH) microscopy has proven to be a powerful imaging modality over the past years due to its intrinsic advantages as a multiphoton process with endogenous contrast specificity, which allows pinhole-less optical sectioning, non-invasive observation, deep tissue penetration, and the possibility of easier signal detection at visible wavelengths. Depending on the relative orientation between the polarization of the incoming light and the second-order susceptibility of non-centrosymmetric structures, SH microscopy provides the unique capacity to probe the absolute molecular structure of a broad variety of biological tissues without the necessity for additional labeling...
June 14, 2017: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/28614332/dynamics-of-trapped-atoms-around-an-optical-nanofiber-probed-through-polarimetry
#7
Pablo Solano, Fredrik K Fatemi, Luis A Orozco, S L Rolston
The evanescent field outside an optical nanofiber (ONF) can create optical traps for neutral atoms. We present a non-destructive method to characterize such trapping potentials. An off-resonance linearly polarized probe beam that propagates through the ONF experiences a slow axis of polarization produced by trapped atoms on opposite sides along the ONF. The transverse atomic motion is imprinted onto the probe polarization through the changing atomic index of refraction. By applying a transient impulse, we measure a time-dependent polarization rotation of the probe beam that provides both a rapid and non-destructive measurement of the optical trapping frequencies...
June 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28600515/evaluation-of-intraretinal-migration-of-retinal-pigment-epithelial-cells-in-age-related-macular-degeneration-using-polarimetric-imaging
#8
Masahiro Miura, Shuichi Makita, Satoshi Sugiyama, Young-Joo Hong, Yoshiaki Yasuno, Ann E Elsner, Shigeo Tamiya, Rintaro Tsukahara, Takuya Iwasaki, Hiroshi Goto
The purpose of the present study was to evaluate the intraretinal migration of the retinal pigment epithelium (RPE) cells in age-related macular degeneration (AMD) using polarimetry. We evaluated 155 eyes at various AMD stages. Depolarized light images were computed using a polarization-sensitive scanning laser ophthalmoscope (PS-SLO), and the degree of polarization uniformity was calculated using polarization-sensitive optical coherence tomography (OCT). Each polarimetry image was compared with the corresponding autofluorescence (AF) images at 488 nm (SW-AF) and at 787 nm (NIR-AF)...
June 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28593944/non-ising-and-chiral-ferroelectric-domain-walls-revealed-by-nonlinear-optical-microscopy
#9
Salia Cherifi-Hertel, Hervé Bulou, Riccardo Hertel, Grégory Taupier, Kokou Dodzi Honorat Dorkenoo, Christian Andreas, Jill Guyonnet, Iaroslav Gaponenko, Katia Gallo, Patrycja Paruch
The properties of ferroelectric domain walls can significantly differ from those of their parent material. Elucidating their internal structure is essential for the design of advanced devices exploiting nanoscale ferroicity and such localized functional properties. Here, we probe the internal structure of 180° ferroelectric domain walls in lead zirconate titanate (PZT) thin films and lithium tantalate bulk crystals by means of second-harmonic generation microscopy. In both systems, we detect a pronounced second-harmonic signal at the walls...
June 8, 2017: Nature Communications
https://www.readbyqxmd.com/read/28572577/three-dimensional-geometry-of-collagenous-tissues-by-second-harmonic-polarimetry
#10
Karen Reiser, Patrick Stoller, André Knoesen
Collagen is a biological macromolecule capable of second harmonic generation, allowing label-free detection in tissues; in addition, molecular orientation can be determined from the polarization dependence of the second harmonic signal. Previously we reported that in-plane orientation of collagen fibrils could be determined by modulating the polarization angle of the laser during scanning. We have now extended this method so that out-of-plane orientation angles can be determined at the same time, allowing visualization of the 3-dimensional structure of collagenous tissues...
June 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28504887/co2-controlled-one-pot-synthesis-of-ab-aba-block-and-statistical-terpolymers-from-%C3%AE-butyrolactone-epoxides-and-co2
#11
Sebastian Kernbichl, Marina Reiter, Friederike Adams, Sergei Vagin, Bernhard Rieger
Terpolymerizations of (rac)-β-butyrolactone (BBL), cyclohexene oxide (CHO), and carbon dioxide were realized in one-pot reactions utilizing a Lewis acid BDI(CF3)-Zn-N(SiMe3)2 (1) catalyst. The type of polymerization can be regulated and switched between ring-opening polymerization (ROP) of BBL and CHO/CO2 copolymerization by the presence of CO2 in the reaction mixture. Applying 3 bar CO2 to the three-component system leads to similar reaction rates for copolymerization and ROP and therefore to a terpolymer with a statistical composition, whereas 40 bar CO2 affords exclusive copolymerization of CHO/CO2...
May 15, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28504754/performance-comparison-of-pseudo-inverse-and-maximum-likelihood-estimators-of-stokes-parameters-in-the-presence-of-poisson-noise-for-spherical-design-based-measurement-structures
#12
François Goudail
Estimation of the Stokes vector from N>4 intensity measurements is usually performed with the pseudo-inverse (PI) estimator, which is optimal when the noise that corrupts the measurements is additive and Gaussian. In the presence of Poisson shot noise, the maximum-likelihood (ML) estimator is different from the PI estimator, but is more complex to implement since it is not closed-form. We compare in this Letter the precisions obtained with the ML and the PI estimators in the presence of Poisson noise when using measurement structures based on spherical designs...
May 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28401949/inverting-polar-domains-via-electrical-pulsing-in-metallic-germanium-telluride
#13
Pavan Nukala, Mingliang Ren, Rahul Agarwal, Jacob Berger, Gerui Liu, A T Charlie Johnson, Ritesh Agarwal
Germanium telluride (GeTe) is both polar and metallic, an unusual combination of properties in any material system. The large concentration of free-carriers in GeTe precludes the coupling of external electric field with internal polarization, rendering it ineffective for conventional ferroelectric applications and polarization switching. Here we investigate alternate ways of coupling the polar domains in GeTe to external electrical stimuli through optical second harmonic generation polarimetry and in situ TEM electrical testing on single-crystalline GeTe nanowires...
April 12, 2017: Nature Communications
https://www.readbyqxmd.com/read/28386442/polarimetry-of-pinctada-fucata-nacre-indicates-myostracal-layer-interrupts-nacre-structure
#14
Rebecca A Metzler, Joshua A Jones, Anthony J D'Addario, Enrique J Galvez
The inner layer of many bivalve and gastropod molluscs consists of iridescent nacre, a material that is structured like a brick wall with bricks consisting of crystalline aragonite and mortar of organic molecules. Myostracal layers formed during shell growth at the point of muscle attachment to the shell can be found interspersed within the nacre structure. Little has been done to examine the effect the myostracal layer has on subsequent nacre structure. Here we present data on the structure of the myostracal and nacre layers from a bivalve mollusc, Pinctada fucata...
February 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28386426/celestial-polarization-patterns-sufficient-for-viking-navigation-with-the-naked-eye-detectability-of-haidinger-s-brushes-on-the-sky-versus-meteorological-conditions
#15
Gábor Horváth, Péter Takács, Balázs Kretzer, Szilvia Szilasi, Dénes Száz, Alexandra Farkas, András Barta
If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog...
February 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28384706/stokes-mueller-matrix-polarimetry-technique-for-circular-dichroism-birefringence-sensing-with-scattering-effects
#16
Quoc-Hung Phan, Yu-Lung Lo
No abstract text is available yet for this article.
April 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28383522/investigating-starch-gelatinization-through-stokes-vector-resolved-second-harmonic-generation-microscopy
#17
Nirmal Mazumder, Lu Yun Xiang, Jianjun Qiu, Fu-Jen Kao
The changes of the morphology during heating and the degree of crystallinity of dry and hydrated starch granules are investigated using second harmonic generation (SHG) based Stokes polarimetry. A spatial distribution of various polarization parameters, such as the degree of polarization (DOP), the degree of linear polarization (DOLP), and the degree of circular polarization (DOCP) are extracted and compared with the two dimensional second harmonic (SH) Stokes images of starch granules. The SH signal from hydrated and dry starch on heating differed significantly in DOLP and DOCP values, indicating that hydrated starch has a greater degree of ultrastructural amylopectin disorder...
April 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28380013/polarization-image-segmentation-of-radiofrequency-ablated-porcine-myocardial-tissue
#18
Iftikhar Ahmad, Adam Gribble, Iqbal Murtza, Masroor Ikram, Mihaela Pop, Alex Vitkin
Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA) lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy) zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image...
2017: PloS One
https://www.readbyqxmd.com/read/28366205/-the-origins-of-analysis-and-of-drugs-control
#19
O Lafont
Analytical concerns were quite ancient. As soon as the 12th century, Al-Chayzari searched drugs falsifications. During the 17th century, retort analysis was much practiced. Selective extraction constituted a great progress. During the 18th century, gas volumetric analysis appeared. Descroizilles created volumetric analysis in liquid phase, and that gave him the opportunity for creating acidi-alcalimetry methods. Following the works of Gay-Lussac and Thénard, Liebig invented an apparatus for performing elemental analysis of organic compounds...
March 30, 2017: Annales Pharmaceutiques Françaises
https://www.readbyqxmd.com/read/28352074/optimized-mass-spectrometry-analysis-workflow-with-polarimetric-guidance-for-ex-vivo-and-in-situ-sampling-of-biological-tissues
#20
Michael Woolman, Adam Gribble, Emma Bluemke, Jing Zou, Manuela Ventura, Nicholas Bernards, Megan Wu, Howard J Ginsberg, Sunit Das, Alex Vitkin, Arash Zarrine-Afsar
Spatially Targeted Mass Spectrometry (MS) analysis using survey scans with an imaging modality often requires consecutive tissue slices, because of the tissue damage during survey scan or due to incompatible sample preparation requirements between the survey modality and MS. We report two spatially targeted MS analysis workflows based on polarized light imaging guidance that use the same tissue sample for survey and targeted analysis. The first workflow is applicable for thin-slice analysis, and uses transmission-polarimetry-guided Desorption ElectroSpray Ionization Mass Spectrometry (DESI-MS), and confirmatory H&E histopathology analysis on the same slice; this is validated using quantitative digital pathology methods...
March 28, 2017: Scientific Reports
keyword
keyword
37478
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"