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Alessandra Tata, Michael Woolman, Manuela Ventura, Nicholas Bernards, Milan Ganguly, Adam Gribble, Bindesh Shrestha, Emma Bluemke, Howard J Ginsberg, Alex Vitkin, Jinzi Zheng, Arash Zarrine-Afsar
Identification of necrosis in tumors is of prognostic value in treatment planning, as necrosis is associated with aggressive forms of cancer and unfavourable outcomes. To facilitate rapid detection of necrosis with Mass Spectrometry (MS), we report the lipid MS profile of necrotic breast cancer with Desorption Electrospray Ionization Mass Spectrometry (DESI-MS) imaging validated with statistical analysis and correlating pathology. This MS profile is characterized by (1) the presence of the ion of m/z 572.48 [Cer(d34:1) + Cl](-) which is a ceramide absent from the viable cancer subregions; (2) the absence of the ion of m/z 391...
October 13, 2016: Scientific Reports
H J Hoeijmakers, M L J Arts, F Snik, C U Keller, J M Kuiper
We provide a proof of the technical feasibility of LOUPE, the first integral-field snapshot spectropolarimeter, designed to monitor the reflected flux and polarization spectrum of Earth. These are to be used as benchmark data for the retrieval of biomarkers and atmospheric and surface characteristics from future direct observations of exoplanets. We perform a design trade-off for an implementation in which LOUPE performs snapshot integral-field spectropolarimetry at visible wavelengths. We used off-the-shelf optics to construct a polarization modulator, in which polarization information is encoded into the spectrum as a wavelength-dependent modulation, while spatial resolution is maintained using a micro-lens array...
September 19, 2016: Optics Express
Geminiano Martinez-Ponce
Three types of polarization gratings have been recorded in azopolymer films by the symmetrical superposition of different orthogonal pairs of polarized beams. The inscribed holographic elements have been analyzed microscopically in a Mueller polarimeter in order to image the optical anisotropies photoinduced in the film. In the most of cases, the spatial modulation of diattenuation, birefringence, and optical rotation reproduced quite well previous results reported in the literature. Nevertheless, in the particular case of coherent superposition of p- and s-polarized beams, the spatial frequency for optical rotation (related to the Stokes parameter V) was different from the one observed in linear anisotropy (related to the Stokes parameter U)...
September 19, 2016: Optics Express
Xiaoyan Cui, Shane M Nichols, Oriol Arteaga, John Freudenthal, Froilanny Paula, Alexander G Shtukenberg, Bart Kahr
Accounting for the interactions of light with heterogeneous, anisotropic, absorbing, optically active media is part of the characterization of complex, transparent materials. Stained biological structures in thin tissue sections share many of these features, but systematic optical analyses beyond the employ of the simple petrographic microscopes have not be established. Here, this accounting is made for polycrystalline, spherulitic bundles of twisted d-mannitol lamellae grown from melts containing light-absorbing molecules...
September 21, 2016: Journal of the American Chemical Society
Razvigor Ossikovski, Kurt Hingerl
Starting from the first principles, we derive the expressions governing partially coherent Mueller matrix reflection polarimetry on spatially inhomogeneous samples. These are reported both in their general form and in the practically important specific form for two juxtaposed media.
September 1, 2016: Optics Letters
Arjen C Breman, Gydo van der Heijden, Jan H van Maarseveen, Steen Ingemann, Henk Hiemstra
Six highly enantiopure analogues of [2.2.2] were synthesized with five- or seven-membered rings in the (original) quinuclidine skeleton. Five of these compounds were prepared through epoxide opening by a secondary cyclic amine, providing the nor- and homoquinuclidine moieties through five- and six-membered ring formation. This method failed in the case of seven-membered ring formation, so for that particular ring size a different synthetic route starting from 3-quinuclidone was applied. The six novel analogues were examined as organocatalysts in four asymmetric conjugate addition reactions and the results compared with those of known cinchona alkaloid catalysts...
September 26, 2016: Chemistry: a European Journal
Oriol Arteaga, Zoubir El-Hachemi, Adolf Canillas, Joaquim Crusats, Meritxell Rovira, Josep M Ribó
Mueller matrix polarimetry distinguishes the different origins of the reversible and irreversible chiroptical effects emerging in stirred solutions of J-aggregate nanoparticles: the reversible effect is due to an anisotropic ordering in the solution and the irreversible one is due to a bias from the racemic composition of intrinsically chiral structures.
September 18, 2016: Chemical Communications: Chem Comm
Ching-Han Yang, Yuan-Di Chen, Shing-Trong Wu, Andy Ying-Guey Fuh
We present a simple and flexible method to generate various vectorial vortex beams (VVBs) with a Pancharatnam phase based on the scheme of double reflections from a single liquid crystal spatial light modulator (SLM). In this configuration, VVBs are constructed by the superposition of two orthogonally polarized orbital angular momentum (OAM) eigenstates. To verify the optical properties of the generated beams, Stokes polarimetry is developed to measure the states of polarization (SOP) over the transverse plane, while a Shack-Hartmann wavefront sensor is used to measure the OAM charge of beams...
2016: Scientific Reports
Yang Dong, Honghui He, Chao He, Jialing Zhou, Nan Zeng, Hui Ma
Silk fibers suffer from microstructural changes due to various external environmental conditions including daily washings. In this paper, we take the backscattering Mueller matrix images of silk samples for non-destructive and real-time quantitative characterization of the wavelength-scale microstructure and examination of the effects of washing by different detergents. The 2D images of the 16 Mueller matrix elements are reduced to the frequency distribution histograms (FDHs) whose central moments reveal the dominant structural features of the silk fibers...
2016: International Journal of Molecular Sciences
Thiago H Ito, Airton G Salles, Jacks P Priebe, Paulo C M L Miranda, Nelson H Morgon, Dganit Danino, Giovanna Mancini, Edvaldo Sabadini
Over the past few years, chiral supramolecular assemblies have been successfully used for recognition, sensing and enantioselective transformations. Several approaches are available to control chirality of discrete assemblies (e.g., cages and capsules), but few are efficient in assuring chirality for micellar aggregates. Optically active amino acid-derived surfactants are commonly used to generate chiral spherical micelles. To circumvent this limitation, we benefited from the uniaxial growth of spherical micelles into long cylindrical micelles usually called wormlike or giant micelles, upon the addition of cosolutes...
August 23, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Zhen Fang Yu, Casey W Pirnstill, Gerard L Coté
No abstract text is available yet for this article.
August 1, 2016: Journal of Biomedical Optics
Razvigor Ossikovski, Enric Garcia-Caurel
We derive the relationships between the elementary polarization properties describing a homogeneous medium within the framework of the differential Jones and Mueller formalisms from transmission polarimetry, and the permittivity tensor of the medium, assumed to be weakly anisotropic. The expressions are illustrated on selected examples and allowed to physically interpret experimental polarimetry data.
August 1, 2016: Optics Letters
S Gupta Roy, O M Awartani, P Sen, B T O'Connor, M W Kudenov
Polarimetry has widespread applications within atmospheric sensing, telecommunications, biomedical imaging, and target detection. Several existing methods of imaging polarimetry trade off the sensor's spatial resolution for polarimetric resolution, and often have some form of spatial registration error. To mitigate these issues, we have developed a system using oriented polymer-based organic photovoltaics (OPVs) that can preferentially absorb linearly polarized light. Additionally, the OPV cells can be made semitransparent, enabling multiple detectors to be cascaded along the same optical axis...
June 27, 2016: Optics Express
Jan Dupont, Xavier Orlik
In this paper, we propose the simulation of polarized speckle fields using the Stokes formalism, which allows the description of partially polarized electromagnetic waves. We define a unique parameter which determines the partial decorrelation of the involved fields, allowing to simulate the polarized speckles produced by all types of scatterers, from simple to multiple scatterers. We validate this model by comparison with experimental measurements. We use that simulation model to study the impact of the imaging device parameters on polarimetric measurements: first we emphasize a limit of resolution on retardance measurements, then we study the spatial depolarization, which appears when an observer is measuring any space-variant polarization map...
May 16, 2016: Optics Express
R M A Azzam
This paper reviews the current status of instruments for measuring the full 4×1 Stokes vector S, which describes the state of polarization (SOP) of totally or partially polarized light, and the 4×4 Mueller matrix M, which determines how the SOP is transformed as light interacts with a material sample or an optical element or system. The principle of operation of each instrument is briefly explained by using the Stokes-Mueller calculus. The development of fast, automated, imaging, and spectroscopic instruments over the last 50 years has greatly expanded the range of applications of optical polarimetry and ellipsometry in almost every branch of science and technology...
July 1, 2016: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
José J Gil
While any 2D mixed state of polarization of light can be represented by a combination of a pure state and a fully random state, any Mueller matrix can be represented by a convex combination of a pure component and three additional components whose randomness is scaled in a proper and objective way. Such characteristic decomposition constitutes the appropriate framework for the characterization of the polarimetric randomness of the system represented by a given Mueller matrix and provides criteria for the optimal filtering of noise in experimental polarimetry...
July 10, 2016: Applied Optics
Amol V Pansare, Dnyaneshwar K Kulal, Amol A Shedge, Vishwanath R Patil
Selenium nanoparticles (SeNPs) have attracted great attention because of their superior optical properties and wide utilization in biological and biomedical studies. This paper reports an environmentally benign procedure of greener monodispersible SeNP synthesis using the reducing power of Trigonella foenum-graecum extract, characterization and their protective effect against unfolded (Herring sperm DNA) hsDNA. We investigated the anti-cancer activity of SeNPs against MCF-7, MDA MB 435 and COLO-205 cells. The photocatalytic activity of SeNPs was investigated for the degradation of a Sunset Yellow FCF (SYFCF) dye using ultraviolet-B light...
July 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Razvigor Ossikovski, Jérémy Vizet
We report on the identification of the two algebraic invariants inherent to Mueller matrix polarimetry measurements performed through double pass illumination-collection optics (e.g., an optical fiber or an objective) of unknown polarimetric response. The practical use of the invariants, potentially applicable to the characterization of nonreciprocal media, is illustrated on experimental examples.
July 1, 2016: Optics Letters
Ming-Liang Ren, Rahul Agarwal, Pavan Nukala, Wenjing Liu, Ritesh Agarwal
We demonstrate that optical second harmonic generation (SHG) can be utilized to determine the exact nature of nanotwins in noncentrosymmetric crystals, which is challenging to resolve via conventional transmission electron or scanned probe microscopies. Using single-crystalline nanotwinned CdTe nanobelts and nanowires as a model system, we show that SHG polarimetry can distinguish between upright (Cd-Te bonds) and inverted (Cd-Cd or Te-Te bonds) twin boundaries in the system. Inverted twin boundaries are generally not reported in nanowires due to the lack of techniques and complexity associated with the study of the nature of such defects...
July 13, 2016: Nano Letters
A G Actis, E Versino, B Brogliatti, T Rolle
PURPOSE: Aim of this retrospective, observational study is to describe features of a population sample, affected by primary open angle glaucoma (POAG) in order to evaluate damage progression on the basis of the emerged individual risk factors. METHODS: We included 190 caucasian patients (377 eyes), evaluating relationship between individual risk factors (explicative variables) and MD (Mean Deviation) of standard automated perimetry. We also considered the dependent variable NFI (Neural Fiber Index) of GDx scanning laser polarimetry...
2016: Open Ophthalmology Journal
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