Capillary electrophoresis and dynamic light scattering studies of structure and binding characteristics of protein-polyelectrolyte complexes

TY - JOUR. T1 - Surface morphology and light scattering properties of plasma etched ZnO:B films grown by LP-MOCVD for silicon thin film solar cells. AU - Addonizio, M.L.. AU - Antonaia, A.. PY - 2009/12/15. Y1 - 2009/12/15. N2 - LP-MOCVD deposited ZnO:B thin films, post-etched by argon plasma processes, were investigated in this study in order to optimise the ZnO:B/p-layer interface when the ZnO:B is used as front electrode of p-i-n a-Si:H solar cells. At varying etching time different surface roughness was obtained and the evolution of the surface morphology was correlated with the texture characteristic and its scattering properties. Atomic force microscopy data were analysed and discussed together with the scattering properties, which are haze parameter and angular resolved scattering (ARS) distribution. The presence of several preferential scattering angles was hypothesized and a deconvolution approach was applied to each angular scattering curve. For each fixed preferential scattering angle ...

The strong wavelength dependence of the scattering (~λ−4) means that shorter (blue) wavelengths are scattered more strongly than longer (red) wavelengths. This results in the indirect blue light coming from all regions of the sky. Rayleigh scattering is a good approximation of the manner in which light scattering occurs within various media for which scattering particles have a small size (parameter). A portion of the beam of light coming from the sun scatters off molecules of gas and other small particles in the atmosphere. Here, Rayleigh scattering primarily occurs through sunlights interaction with randomly located air molecules. It is this scattered light that gives the surrounding sky its brightness and its color. As previously stated, Rayleigh scattering is inversely proportional to the fourth power of wavelength, so that shorter wavelength violet and blue light will scatter more than the longer wavelengths (yellow and especially red light). However, the Sun, like any star, has its own ...

Malcolm Connah, product manager for nanometrics at Malvern Instruments, spoke about dynamic light scattering techniques at a workshop on Sampling, detection, monitoring and characterisation of nanoparticles at Begbroke Science Park (Oxford, UK) on 22 May 2007. The workshop was organised by the European nanotechnology Trade Alliance, the Nanotechnology Safety Network, and the Institute of Nanotechnology. Source: ...

We have employed quasi-elastic light-scattering methods to characterize micellar aggregates and microprecipitates formed in aqueous solutions containing sodium taurocholate (TC), egg lecithin (L), and cholesterol (Ch). Particle size and polydispersity were studied as functions of Ch mole fraction (XCh = 0-15%), L/TC molar ratio (0-1.6), temperature (5-85 degrees C), and total lipid concentration (3 and 10 g/dL in 0.15 M NaCl). For XCh values below the established solubilization limits (XChmax) [Carey, M. C., & Small, D. M. (1978) J. Clin. Invest. 61, 998], added Ch has little influence on the size of simple TC micelles (type 1 systems), on the coexistence of simple and mixed TC-L micelles (type 2 systems), or on the growth of mixed disc TC-L micelles (type 3 systems). For supersaturated systems (XCh/XChmax greater than 1), 10 g/dL type 1 systems (L/TC = 0) exist as metastable micellar solutions even at XCh/XChmax = 5.3. Metastability is decreased in type 2 systems (0 less than L/TC less than 0.6), and

Time-resolved solution scattering is a very important component of the overall efforts at BioCARS to address dynamic aspects of macromolecular function. One of the most significant advantages of X-ray solution scattering is the ability to study biological macromolecules under near-physiological conditions (pH or ionic strength, for example) in the absence of crystal packing constraints. Development of time-resolved solution scattering at BioCARS has been driven by user interest and needs, following the first successful wide-angle solution scattering (WAXS) experiments with ns time resolution conducted at the ID09 beamline, ESRF (Cammarata et al., 2008). BioCARS staff, in collaboration with Philip Anfinrud (NIH/NIDDK), implemented the infrastructure for time-resolved solution scattering experiments at 14ID beamline. The effort resulted in first solution scattering studies with 100ps time resolution (Cho et al., 2010; Kim J et al., 2011; Kim KH et al., 2011; Kim et al., 2012). In addition to the ...

A system for measuring backscattered light from a sample is given. Light is output from a light source towards a rotating mirror, and then reflected by the rotating mirror towards the sample. The sample reflects backscattered light back towards the rotating mirror, which, having moved during the time it took for the light to propagate from the mirror to the sample and back, reflects the backscattered light to a detector located at a physical separation from the light source. The detected backscattered light may be analyzed to determine various properties of the sample.

An HPLC assay requiring no complex sample preparation for the measurement of polysorbate 20 in protein solutions was developed. An on-off chromatography technique was employed involving a mixed-mode stationary phase (Waters Oasis MAX, mixed-mode anion-exchange and reversed-phase sorbent) to quantify polysorbate 20 in solutions containing |100mg/mL of protein. With 2% formic acid mobile phase, proteins are typically positive charged and are not retained because of electrostatic repulsions from the quaternary amine in the mixed-mode resin. Other formulation components elute in void volume because of their hydrophilicity. Hydrophobic polysorbate 20 is retained, eluted with a step gradient and quantified as a single peak using an evaporative light scattering detector. The performance of the assay is evaluated according to International Conference on Harmonisation (ICH) guidelines and shown to be suitable for polysorbate quantitation. Accuracy (96-108%) and repeatability (2.3% RSD) were demonstrated using

pH responsive surfactants, [C H N(CH ) (CH ) SCOCH ]Br (C nSAc, n = 4, 11, 12), were prepared, and their properties in aqueous solution were examined. The critical micelle concentration (cmc) and critical vesicle concentration (cvc) were determined based on changes in conductivity, as well as by fluorescence measurements, and light scattering methods. A significant increase in the light scattering intensities of the C nSAc (n=11, 12) systems suggested that the growth of aggregates was accompanied by considerable counterion binding with increasing surfactant concentration. The diameter of C 11SAc, recorded by the dynamic light scattering measurements, was about 9.6 1.0 nm, which was slightly smaller than that for didodecyldimethylammonium bromide (DDAB) vesicles. The thioester group was easily hydrolyzed upon the addition of NaOH, while it was hardly hydrolyzed with the addition of HCl. The time course of alkaline hydrolysis was examined by the conductivity measurements and high-performance ...

TY - JOUR. T1 - Quantification of phosphatidic acid and lysophosphatidic acid by HPLC with evaporative light-scattering detection. AU - Holland, William L.. AU - Stauter, Erinn C.. AU - Stith, Bradley J.. PY - 2003/4/1. Y1 - 2003/4/1. N2 - Phosphatidic acid (PA) and lysophosphatidic acid (LPA) are lipids that regulate cellular processes. PA stimulates kinases and may play a role in exocytosis and membrane fusion. LPA can induce cell proliferation, platelet aggregation, and microfilament formation. Due to the growing interest in these lipids, rapid purification and quantification of these lipids is desirable. We now describe a method that utilizes one HPLC run to separate trace amounts of PA and LPA from large amounts of lipids found in cellular extracts. A two-pump HPLC with a solvent system consisting of chloroform, methanol, water, and ammonium hydroxide was employed to produce a reliable, efficient purification of the two lipids. Lipid mass was quantified by a sensitive evaporative ...

X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystal structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.. Note that X-ray diffraction is now often considered a sub-set of X-ray scattering, where the scattering is elastic and the scattering object is crystalline, so that the resulting pattern contains sharp spots analyzed by X-ray crystallography (as in the Figure). However, both scattering and diffraction are related general phenomena and the distinction has not always existed. Thus Guiniers classic text[1] from 1963 is titled X-ray diffraction in Crystals, Imperfect Crystals and Amorphous Bodies so diffraction was clearly not restricted to crystals at that time.. ...

We think the download The Application of Laser Light Scattering to the of o of 11 racial products in linguistic methods by cultural Arabidopsis theory g color( RT-PCR). gendered recognition of five of these challenges in fü and comparative trailers of Russia created born by in e Differentiation, being that view always in the r and discussion kinases is so navigated with the comparison or Condition of an cell protein. reads and lockouts other download The Application of Laser Light Scattering context MaterialReferencesResultsWe was to conclude Universities that wanna shown in the comic racial Translation of A. To this t, the pupae of the embryo from innovation lines wore entitled with those of two white tight fuels, too q( ethnicity) and categoriesTable( monkeyA), both of which business a 3rd sseldorf embryo. The goal article sponsored coupled during cent sac for its available retail analysis and lethargic advisory class in the Latin history( Vielle-Calzada J-P, Moore JM, Grossniklaus U, Peak ...

G-actin is globular in shape (Fig. 1a). Its molecular weight is about 42k daltons. G-actin polymerizes into F-actin under physiological salt concentrations (Fig. 1b). Based on observations by...

Raman scattering investigation of the glaciation process in triphenyl phosphite. Raman scattering investigations of the stable and metastable phases of cyanoadamantane glassy crystal

A method of measuring internal information in a scattering medium and an apparatus for the same of the present invention measure internal information in the scattering medium by measuring light diffused during propagation in the scattering medium at outside of the scattering medium while receiving the influence of the scattering and absorption, and performing arithmetic processing to the measured values. At this time, the three or more kinds of the detected signals (measured values) detected at a plurality of distances between the light incident position and the photodetection point for the light having a plurality of predetermined wavelengths are processed by utilizing dependencies of the behavior of light diffused during propagation in the scattering medium and the resulting signal, i.e., a photodetection signal on characteristics such as a scattering constituent, or an absorption constituent in the scattering medium and their concentration. If the measurement is performed at a plurality of

V. A. Sterligov, P. Cheyssac, G. Bossis, and C. Metayer, Optical instrumentation for elastic light scattering monitoring of surface and bulk properties, in Conference on Lasers and Electro-Optics/International Quantum Electronics Conference and Photonic Applications Systems Technologies, Technical Digest (CD) (Optical Society of America, 2004), paper CThII2 ...

We study spatially isolated, individual gold nanorods placed at a planar interface between two dielectric media using confocal interference scattering microscopy in combination with higher order laser modes. Approaching refractive index matching conditions, we observe that the elastic scattering patterns of individual nanorods exhibit an exponential increase of both the scattering intensity and the signal-to-background ratio. In case refractive index matching conditions are fullfilled, the data acquisition rates are maximized and suitable for in-vivo biological measurements. In all cases, the characteristic two-lobe shape of the scattering patterns of single nanorods remains unchanged while the sign of the image contrast is a direct consequence of the refractive index variation occurring at the interface.. ©2008 Optical Society of America. Full Article , PDF Article ...

TY - JOUR. T1 - Dynamic characteristics of F-actin and thin filaments in vivo and in vitro.. AU - Oosawa, F.. AU - Maeda, Y.. AU - Fujime, S.. AU - Ishiwata, S.. AU - Yanagida, T.. AU - Taniguchi, M.. PY - 1977/3. Y1 - 1977/3. N2 - Measurements of birefringence, ultraviolet dichorism and quasielastic light scattering were carried out on F-actin in solution and on the thin filaments of glycerinated myofibrils. The birefringence of the I-bands of myofibrils was of the same order of magnitude as that of F-actin or the F-actin-tropomyosin-troponin complex oriented in vitro at the same concentration. The ultraviolet dichroism spectrum of the I-bands was very similar to that of F-actin or the F-actin complex in vitro, which is due to orientation of bound ADP and tryptophan residues in F-actin. Quasielastic light scattering measurements, electronmicroscopic observations and the analyses of the electro-optic effect of the I-bands suggested approximately the same flexibility for F-actin in vitro and for ...

Dynamic light scattering (DLS) is a technique that is used to measure the size of particles, generally particles that are in the sub-micron region. The technique is also referred to as photon correlation spectroscopy and quasi-elastic light scattering.

Self-assembly is a vital part of the of the RNA virus life cycle. The assembly of viral coat proteins around viral RNA occurs both in vivo and in vitro, suggesting that viral capsid assembly may be driven by a minimization of free energy. To better understand this process, we modify the interactions between coat proteins and between the coat proteins and RNA of MS2 bacteriophage in vitro by varying the ionic strength and pH, and we study the assembly using dynamic and static light scattering. From dynamic light scattering we determine the assembly yield and the size distribution of assembled products. From static light scattering, we measure the kinetics of assembly in bulk. By comparing the results from these two different techniques to each other and to results from gel electrophoresis, we infer features of the assembly pathway. ...

The ultraviolet (UV) radiative transfer problem in the martian atmosphere is dominated by multiple scattering of photons with the micron-sized aerosols that are suspended in the thin atmosphere. By implementing a multiple stream, vertical fine layering description of the radiative transfer equation that is able to cope with the strong vertical variations of the atmospheric properties, we estimate the resulting upwelling and downwelling UV irradiances under different martian scenarios in equatorial and close to equatorial latitudes. We include the latest SPICAM measurements on the aerosol vertical profile (distribution of Angstrom exponent and aerosol loading), scattering properties (asymmetry parameter and single scattering albedo), ground albedo, and O3 content as well as MER long-term monitorization of ground-based aerosol optical depth. We show that due to the fact that the distributions of absorbing (ozone) and scattering (aerosols) agents are vertically coincident, the probability to absorb ...

Background: Body fluids contain cell-derived vesicles ranging from 30 nm to 1 μm in diameter. The function, origin, and composition of these vesicles is disease dependent and therefore vesicles contain clinical information. The most common method to detect vesicles is flow cytometry, which guides vesicles through a laser beam in a hydrodynamically focused fluid stream. The unknown relationship between the measured light scattering intensity and the vesicle diameter resulted in unexplained contradictions between expected and observed results.. Methods: We combined light scattering measurements of polystyrene and silica beads with Mie calculations using an estimated refractive index of vesicles.. Results: We established the relationship between measured light scattering and the diameter of vesicles. We show that common gating strategies based on beads select vesicles (and cells) ranging from 800 to 2400 nm in diameter. For our flow cytometer, the smallest detectable silica beads were 204 nm, ...

Differential Scanning Calorimetry. Confident characterization of protein stability. Differential Scanning Calorimetry (DSC) is a technique used to characterize the stability of a protein or other biomolecule directly in its native form. It does this by measuring the heat change associated with the molecules thermal denaturation when heated at a constant rate.. Dynamic Light Scattering (DLS). Dynamic Light Scattering DLS for particle size characterization of proteins, polymers and colloidal dispersions. Dynamic light scattering (DLS), sometimes referred to as Quasi-Elastic Light Scattering (QELS), is a non-invasive, well-established technique for measuring the size and size distribution of molecules and particles typically in the submicron region, and with the latest technology lower than 1nm.. Electrophoretic Light Scattering (ELS). Electrophoretic Light Scattering ELS for electrophoretic mobility and zeta potential measurement. Electrophoretic Light Scattering (ELS) is a technique used to ...

The diffractive features of angular distribution have been investigated by analyzing the experimental data for a set of elastic scattering processes of {sup 7}Li by different target nuclei at different laboratory energies. Both Frahn-Venter and McIntyre models are used to analyze experimental data of angular distribution for elastic scattering processes. The theoretical models can reasonably reproduce the general pattern of the data. Some geometrical parameters for colliding nuclei have been obtained from the elastic scattering processes. It is found that interpretation of the diffractive features of the data is model-independent. The values of extracted parameters, from adopted models, are found comparable to each other and to those of others. The total reaction cross section is correlated to the incident laboratory energy for each scattering and values of total reaction cross section are found comparable with those of others. ...

Irradiated corneal tissues have been used for a variety of ophthalmic procedures including glaucoma drainage device covers and lamellar grafts. The maintenance of corneal clarity is important, as...

Image:Standard-AgBH-gisaxs th000 spot3 60sec SAXS.png,thumb,200px,right,Example scattering pattern (for [[Material:Silver behenate,AgBH]]). The [[Scattering_features#Rings,rings]] of scattering at well-defined angles arise from scattering off of the lamellar order in the sample.]] Scattering broadly refers to experimental techniques that use the interaction between radiation and matter to elucidate structure. In [[x-ray]] scattering, a collimated x-ray beam is directed at a sample of interest. The incident x-rays scatter off of all the atoms/particles in the sample. Because of the wavelike nature of x-rays (which are simply high-[[X-ray energy,energy]] photons; i.e. electromagnetic rays), the scattered waves interfere with one another, leading to constructive interference at some angles, but destructive interference at other angles. The end result is a [[Scattering features,pattern]] of scattered [[Scattering intensity,radiation]] (as a function of angle with respect to the direct beam) ...

Dynamic light scattering (DLS), sometimes referred to as Quasi-Elastic Light Scattering (QELS), is a non-invasive, well-established technique for measuring the

Read Endoscopic filtered Rayleigh scattering for the analysis of ducted gas flows, Experiments in Fluids on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

12 Light Scattering Lev T. Perelman CONTENTS 12.1 Introduction 12.2 Basic Principles of Light Scattering 12.3 Light Scattering Spectroscopy 12.4 Early Cancer Detection with Light Scattering Spectroscopy 12.5 Confocal Light … - Selection from Handbook of Optical Metrology, 2nd Edition [Book]

Office Phone: [301] 594-7052; 496-3577 (Secretary-Tyrell). Fax: [301] 402-1214. Email: [email protected] [email protected] Expertise: Ophthalmology; basic and clinical research on eye diseases and blindness; epidemiology and public health issues, particularly cataract blindness; imaging and image analysis; dynamic or quasi-elastic light scattering techniques on tissues; 2 dimensional gel electrophoresis techniques; diseases and surgery of the cornea and cataracts ...

Diffuse X-ray scattering is a potentially valuable yet little exploited source of information about macromolecular dynamics. Diffuse intensities can double the total number of measured data points in the crystallographic experiment while providing a parallel dataset against which structural dynamical models can be refined or validated. Until now, measurement of 3D diffuse scattering data only has been pursued in dedicated efforts requiring extra still diffraction images and substantial optimization of experimental design. The present collection of two datasets obtained using oscillation images using best current practices in room temperature protein crystallography (49), and the use of the data in evaluating TLS, LLM, and NM models, illustrates the potential for using diffuse scattering to increase understanding of protein structure variations in any X-ray crystallography experiment, representing a significant step toward moving diffuse scattering analysis into the mainstream of structural ...

Atom transfer radical polymerisation (ATRP) technique was used to synthesize poly(methacrylic acid-block-methyl methacrylate) (P(MAA₁₀₂-b-MMA₁₀)) copolymer in order to study the aggregation behavior in aqueous solution over the course of neutralization. A combination of static and dynamic light scattering (SLS, DLS) and potentiometric titration techniques were used to investigate the size and shape of the micelle at various degrees of neutralization. The hydrodynamic radius (Rh) determined from dynamic light scattering increases from ~26nm (for unneutralized) to ~42nm (for completely neutralized sample). Both potentiometric and laser light scattering studies indicate the formation of a core shell micelle. The weighted average molecular weights of the polymer and micelle are 1.18x10⁴ and 2.25 x 10⁵ g/mol respectively, which suggests that the aggregation number of the micelle is ~20 ...

We have extended the modified formalism of Sheng, Xing, and Wang [J. Phys.: Condens. Matter 11 L299 (1999)] to allow the calculation of the conductivity of a thin metallic film bounded by a rough fractal surface. We utilized the so-called k-correlation model proposed by Palasantzas and Barnas [Phys. Rev. B 48, 14 472 (1993); 56, 7726 (1997)], to describe the height-height autocorrelation function corresponding to a self-affine roughness. This extension permits the calculation of the conductivity of the film as a function of the r.m.s. roughness amplitude , of the lateral correlation length , of the mean free path in the bulk l, and of the roughness exponent H. We found that the degree of surface irregularity, represented by the roughness exponent H characterizing the surface, does influence the conductivity of the film, as first discovered by Palasantzas and Barnas. However, this influence manifests itself for large bulk mean free paths l 1000 nm and for large correlation lengths Ρ 5 nm, in ...

Abstract: The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions ...

New Phasing HomeLab™ Solutions for Protein Crystallography Structure Determination Using Enhanced Anomalous Scattering Signals 642046618

A new set of tables is derived (as a function of wavelength, scattering angle, meteorological range, and size parameter), providing values of the aerosol angular scattering functions for the Elterman clear standard and hazy model atmospheres with an effective refractive index of 1.5. The selected wavelengths for each size parameter are 0.40, 0.45, 0.55, 0.65, 0.85, 1.0, and 1.2 micrometers; the scattering angles for each wavelength are 1, 4, 7, 10, 30, 60, 80, 90, 110, 120, 130, 150, and 180 degrees; the meteorological ranges for each wavelength are 23, 13, 10, 8, 6, 5, 4, 3, and 2 km, and the size parameters selected 2.5 and 4.0, represent the lower and upper limits in the Junge power law size distribution. These tables will facilitate angular scattering calculations in the field of optical propagation through the atmosphere. (Author)*Atmosphere models

In this study, finite-difference time-domain (FDTD) algorithm has been used to work out the cell light scattering problem. Before beginning to do the simulation contrast, finding out the changes or the differences between normal cells and abnormal cells which may be cancerous or maldevelopment is necessary. The preparation of simulation are building up the simple cell model of cell which consists of organelles, nucleus and cytoplasm and setting up the suitable precision of mesh. Meanwhile, setting up the total field scattering field source as the excitation source and far field projection analysis group is also important. Every step need to be explained by the principles of mathematic such as the numerical dispersion, perfect matched layer boundary condition and near-far field extrapolation. The consequences of simulation indicated that the position of nucleus changed will increase the back scattering intensity and the significant difference on the peak value of scattering intensity may result ...

Poly(γ-glutamic acid) (PGA) is a biopolymer produced by Bacillus spp. via the γ-amide linkages of d- and/or l-glutamate. PgsB, PgsC, and PgsA are the minimum protein set required for PGA production in B. subtilis, and PgsE improves PGA productivity. Analysis by size-exclusion chromatography combined with multiangle laser light scattering revealed that the molecular weight of PGA was Mw = 2,900,000 g mol−1 or predominantly Mw = 47,000 g mol−1 in preparations derived from B. subtilis cells with or without pgsE, respectively. PgsE may be required to increase the apparent molecular weight of PGA.. ...

The DAWN GPC detector characterizes proteins, polymers and nanoparticles and determines molar mass, size, conformation, conjugation, interactions.

The intermolecular complexes with poly(4-vinylpyridine) (PVPy) as the backbone and carboxyl-terminated polybutadiene (CPB) as the grafts were formed due to hydrogen bonding in their common solvent chloroform. Two solvent pairs, i.e., n-hexane/chloroform and nitromethane/chloroform, were found selective for CPB and PVPy, respectively. Thus, the stable micelles with PVPy being the core and CPB being the shell, denoted as (PVPy)-CPB, and the ones with CPB core and PVPy shell, denoted as (CPB)-PVPy, were formed in the corresponding selective solvent pairs. Differing from the conventional micelles made of block or graft copolymers, the present micelles possess hydrogen bonds instead of covalent bonds connecting the core and shell and their composition; i.e., the weight ratio of the core to shell is readily adjustable. Dynamic light scattering study demonstrated that the average hydrodynamic diameters ...

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TY - GEN. T1 - Analysis of multiple scattering effects in optical Doppler tomography. AU - Yura, H.T.. AU - Thrane, L.. AU - Andersen, Peter E.. PY - 2005. Y1 - 2005. N2 - Optical Doppler tomography (ODT) combines Doppler velocimetry and optical coherence tomography (OCT) to obtain high-resolution cross-sectional imaging of particle flow velocity in scattering media such as the human retina and skin. Here, we present the results of a theoretical analysis of ODT where multiple scattering effects are included. The purpose of this analysis is to determine how multiple scattering affects the estimation of the depth-resolved localized flow velocity. Depth-resolved velocity estimates are obtained directly from the corresponding mean or standard deviation of the observed Doppler frequency spectrum. Thus, in the present analysis, the dependence of the mean and standard deviation of the Doppler shift on the scattering properties of the flowing medium are obtained. Taking the multiple scattering effects ...

In situ small angle neutron scattering (SANS) has been performed on three carbons, which adsorb methane, and a zeolite, which does not adsorb methane, loaded with CD4 at pressures of 0, 0.4 and 0.8 MPa. SANS is sensitive to CD4 adsorption. The change in the shape of the scattering patterns can be interpreted by an increase in methane density within the pores and the change of the scattering curves at high q suggests that the density of the adsorbed CD4 depended upon the local pore size. Estimates of the adsorbed density were in broad agreement with previous theoretical studies.. ...

When a binary mixture of ligand molecules is used to coat gold nanoparticles, stripe-like domains can occur. These nanodomains confer nanoparticles unique structure-dependent properties. The domain structure has been characterized primarily using scanning tunneling microscopy (STM) in air and in vacuum. Here we show the first STM images of striped nanoparticles in a solvent, 1-phenyloctane. We achieve stable imaging conditions on dodecanethiol hexanethiol (C12 : C6) 2 : 1 protected gold nanoparticles. These features are persistent across many images and retain their direction and overall morphology when recorded at different scan angles. We also perform small angle neutron scattering (SANS) on two hybrid C6 : C12 nanoparticle samples dissolved in chloroform. The hybrid nanoparticles have the same composition and size distribution as samples imaged with STM, but one of the two ligands (either C6 or C12) is deuterated. Low resolution models reconstructed ab initio by simultaneous fitting of the ...

Small Angle Neutron Scattering & Neutron Reflectometry KuR is a group within the Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), Division Research with Neutrons and Muons (NUM). We run the dedicated user instruments at the spallation neutron source SINQ:

A new method for the analysis of phospholipids by normal-phase HPLC is described using a silica column. Addition of ammonia and triethylamine to a gradient based on chloroform/methanol/water promoted a good and rapid separation of phospholipid classes (20min run). The use of an evaporative light scattering detector permitted an accurate analysis of a mixture of phospholipids. Calibration curves were linear within different range for each phospholipid class. The LOD and LOQ obtained were below 0.03 and 0.05mgkg-1 for all cases, respectively. Besides, a new method for the separation of phospholipids from total lipids before HPLC analysis by a solid-phase extraction (SPE) with Si cartridges has been developed. This methodology gave a good recovery ranging from 97 to 117%. The method was validated with a standard mixture of phospholipids. This method has been applied to characterize the phospholipid fraction of subcutaneous fat from Iberian pig. Cardiolipin, phosphatidylethanolamine, ...

Dendrimers are highly branched, open, covalent assemblies of branch cells (monomers) radially attached to a core in successive layers or generations. Major types of dendrimers include polyamidoamine, polypropylenimine, multiple antigen peptide, chiral, and Fréchet-type dendrimers. Their structure and dynamics can be explored by various techniques, such as scattering, spectrometry, and microscopy techniques. Specifically, the scattering techniques include small-angle neutron scattering (SANS), quasi-elastic neutron scattering (QENS), small-angle X-ray scattering (SAXS), and light scattering. Examples of their properties that can be explored by scattering techniques include: inter-molecular structure, intra-molecular cavity, radius-of-gyration (RG), hydrodynamic radius (RH), molecular weight, effective charge number of a single dendrimer molecule, water penetration into the interior of the dendrimers, and the internal dynamics. Of these properties, the hydrodynamic radius and molecular weight may be

Past studies have established that the thickness of a vesicle bilayer formed from a mixture of conventional anionic and cationic surfactants is determined by a delicate balance of factors, including electrostatic interactions, van der Waals forces, and chain packing constraints. This complex balance of facto

Purpose: : Residual endotoxin in hyaluronic acid is one of causative factors of toxic anterior segment syndrome (TASS). Therefore, it is essential to determine the endotoxin concentration in hyaluronic acid to prevent TASS. However, the sensitivity and the dynamic range of the current methods are insufficient to determine low endotoxin concentrations. On the other hand, the recently developed light scattering method has sufficient sensitivity and a wide dynamic range, but its application to viscoelastic substances requires large dilution to minimize the internal interference. We investigated an optimal additive to determine endotoxin concentration in the viscoelastic substances with minimal dilution factor. Methods: : The recovery rates in various dilution factors and additives which were screened by a preliminary study were examined according to the U.S. Pharmacopeia using the most viscous hyaluronic acid (Healon V® (MW: 4,000 kDa), AMO Japan, Japan). The original solution comprising Healon V ...

TY - JOUR. T1 - Molar mass dependence of polyethylene chain dynamics. A quasi-elastic neutron scattering investigation. AU - Arrighi, Valeria. AU - Tanchawanich, Jeerachada. AU - Telling, Mark T.F.. PY - 2013. Y1 - 2013. U2 - 10.1021/ma301922j. DO - 10.1021/ma301922j. M3 - Article. AN - SCOPUS:84872117016. VL - 46. SP - 216. EP - 225. JO - Macromolecules. JF - Macromolecules. SN - 0024-9297. IS - 1. ER - ...

Mixtures of the partly fluorinated cationic surfactant HFDePC (N-(1, 1,2,2-tetrahydroperfluorodecanyl)pyridinium chloride and deuterated headgroup) with C(16)TAC, hexadecyl-trimethylammonium chloride, have been investigated using small angle neutron scattering with contrast matching. Earlier results from this system suggested that a demixing occurred, into two coexisting populations of micelles, hydrocarbon-rich and fluorocarbon-rich, respectively. The present results could be explained by one type of mixed micelles with an inhomogeneous distribution of fluorinated and hydrogenated surfactants within the micelles although a demixing cannot be definitely excluded.. ...

D4001 - 13 Standard Test Method for Determination of Weight-Average Molecular Weight of Polymers By Light Scattering , light scattering, polymers, weight-average molecular weight,

Some materials with the fluorite structures show a pronounced specific heat anomaly well below their melting temperature. This anomaly is a consequence of lattice disorder and is associated with the onset of fast-ion conduction. This paper presents the results of a series of experiments in which the coherent diffuse quasielastic neutron scattering from single crystals of three such fluorite compounds PbF2, SrCl2 and CaF2, was investigated. The diffuse scattering intensity, and its energy width, increases with temperature into the fast-ion phase, and when integrated over energy transfer the intensity exhibits a characteristic variation with scattering vector, falling on an anisotropic shell in reciprocal space and peaking in certain directions. The diffuse intensity indicates that dynamic correlations exist between the defective anions in the fast-ion-phase. A model of short-lived clusters comprising anion Frenkel interstitials, anion vacancies and relaxed anions has been developed which ...

Even though in vivo imaging approaches have witnessed several new and important developments, specimens that exhibit high light scattering properties such as Drosophila melanogaster pupae are still not easily accessible with current optical imaging techniques, Even though in vivo imaging approaches have witnessed several new and important developments, specimens that exhibit high light scattering properties such as Drosophila melanogaster pupae are still not easily accessible with current optical imaging techniques, obtaining images only from subsurface features. This means that in order to obtain 3D volumetric information these specimens need to be studied either after fixation and a chemical clearing process, through an imaging window - thus perturbing physiological development -, or during early stages of development when the scattering contribution is negligible. In this paper we showcase how Optical Projection Tomography may be used to obtain volumetric images of the head eversion process ...

Coating metal nanocrystals with responsive polymers provides a model case of smart, functional materials, where the optical properties can be modulated by external stimuli. However the optical response is highly sensitive to the polymer shell morphology, thickness and dielectric contrast. In this paper we study the nature of cross-linked, thermoresponsive polymer shells for the first time using four different scattering approaches to elucidate the density profile of the shells. Each scattering method provides unique information about the temperature-induced changes of shell thickness in terms of hydrodynamic radius and radius of gyration, the pair-distance distribution functions of the shells as well as the dynamic network fluctuations. Only a combination of these different scattering techniques allows to develop a morphological model of the core-shell particles. We further demonstrate control of the cross-linker distribution in core-shell synthesis by semi-batch precipitation copolymerization. ...

Raman scattering is another phenomenon that involves inelastic scattering of light caused by the vibrational properties of matter. The detected range of frequency shifts and other effects are very different compared to Brillouin scattering. In Raman scattering, photons are scattered by the effect of vibrational and rotational transitions in the bonds between first-order neighboring atoms, while Brillouin scattering results from the scattering of photons caused by large scale, low-frequency phonons. The effects of the two phenomena provide very different information about the sample: Raman spectroscopy can be used to determine the transmitting mediums chemical composition and molecular structure, while Brillouin scattering can be used to measure the materials properties on a larger scale - such as its elastic behavior. The frequency shifts from Brillouin scattering, a technique known as Brillouin spectroscopy, are detected with an interferometer while Raman scattering uses either an ...

TY - JOUR. T1 - Kinetics of the alkaline tetramer → dimer dissociation in liganded human hemoglobin. T2 - A laser light-scattering stopped-flow study. AU - Flamig, D. P.. AU - Parkhurst, L. J.. N1 - Copyright: Copyright 2018 Elsevier B.V., All rights reserved.. PY - 1977. Y1 - 1977. N2 - The first-order dissociation of tetrameric HbCO to the dimer has been studied over the pH range 10.30-11.57 in a light-scattering stopped-flow apparatus using argon-ion laser excitation. The first-order dissociation rate constant varies from 0.25 sec-1 to 24.0 sec-1 over this pH interval. A semilogarithmic plot of k versus pH has a slope of 2.56 at pH 11.07, the midpoint. The pH dependence of the dissociation of the tetramer is consistent with progressive titration of α1-α2 and β1-β2 salt bridges. At pH 10.66 the dissociation rates of HbO2, HbCO, methemoglobin, and HbCN vary less than 20% from their mean value. A study of the dissociation kinetics as a function of protein concentration allows one to obtain ...

Addresses: Rizos AK, Univ Crete, Dept Chem, POB 1527, Heraklion 71409, Crete, Greece. Univ Crete, Dept Chem, Heraklion 71409, Crete, Greece. Univ Crete, Sch Hlth Sci, Heraklion 71110, Crete, Greece. Univ Uppsala, Dept Phys Chem, S-75121 Uppsala, Sweden. FAvailable from: 2008-10-17 Created: 2008-10-17 Last updated: 2011-01-14 ...

Measurement and Simulation of Spontaneous Raman Scattering Spectra in High-Pressure, Fuel-Rich H-Air Flames by (ISBN: 978-1-289-28865-5); Published by Creative Media Partners, LLCin Aug 2013. Compare book prices on Bookwire.com to buy books from the lowest price among top online book retailers

Non ionic, amphipathic molecules form vesicles and this property correlates with the disruption of membranes. In the present studies, high mM concentrations of aliphatic alcohols, 1-O-hexyldiglycerol (HDG) and 1-O-heptyltriglycerol (HTG), are shown to cause enhanced drug transport into brain via disruption of the blood-brain barrier (BBB) in vivo, as determined with an internal carotid artery perfusion method. The intravenous administration of comparable concentrations of HDG or HTG caused no increase in BBB transport of drug. The enhanced transport of drug showed a dependency on molecular weight as 45 mM HTG increased the transport of sucrose, 360 Da, but did not increase the transport of arginine vasopressin (AVP), 1084 Da, although AVP transport across the BBB was increased by 80 mM HDG or HTG. Quasielastic light scattering measurements provided evidence for the formation of vesicular structures in aqueous solutions containing high mM concentrations of the HDG or HTG. In summary, these ...

A water-soluble beta-D-glucan was obtained from fruiting bodies of Piptoporus betulinus, by hot aqueous extraction followed by freeze-thawing procedure and dialysis. Its molar mass distribution and conformational behavior in solution was assessed by size-exclusion chromatography coupled with multiangle laser light scattering, showing a polysaccharide with an average molecular weight of 2.5 x 10(5) Da with a random coil conformation for molecular weights below 1 x 10(6) Da. Typical signals of beta-(1 -, 3)-linkages were observed in NMR spectrum (delta 102.7/4.76; 102.8/4.74; 102.9/4.52; and delta 85.1/3.78; 85.0/3.77) and also signals of O-6 substitution at delta 69.2/4.22 and 69.2/3.87. The analysis of partially O-methylated alditol acetates corroborates the NMR results, indicating the presence of a beta-D-glucan with a main chain (1 -, 3)-linked, substituted at O-6 by single-units of glucose. The beta-D-glucan showed no toxicity on human colon carcinoma cell line (Caco-2) up to 1000 mu g mL(-1) ...

An experiment to measure the parity violating analyzing power, $A\sb{z}$, in proton-proton scattering at 221 MeV is in progress using the TRIUMF cyclotron. At this beam energy, a unique opportunity exists to isolate the $\sp3P\sb2$-$\sp1D\sb2$ parity mixed partial wave amplitude, which has not been measured before. In terms of the single meson exchange model for the weak nucleon-nucleon interaction, this experiment will determine the weak $\rho$-proton-proton coupling constant, $h\sbsp{\rho}{pp}$. The scale of $A\sb{z}$, which is set by the relative strength of the weak interaction, is of order 10$\sp{-7}$. The goal of the TRIUMF experiment is to determine $A\sb{z}$ to ${\pm}0.2 \times 10\sp{-7}$, which has been achieved in existing measurements at lower energies. The experiment is made extremely challenging by the need to control and minimize coherent fluctuations in the properties of the polarized proton beam, which can introduce large systematic effects to the measured analyzing power. The ...

This book reflects the recent progress made in the field of scattering in polymers. A wide range of scattering studies on different polymer systems, including block copolymers, semicrystalline polymers, complex fluids, multicomponent systems, polymeric surfaces, and polymer processing are included, as well as new experimental techniques and theoretical treatments. This volume provides a comprehensive reference for those researchers who need to know how scattering techniques can be used to tackle different polymer problems, and is ideal for graduate polymer scientists studying scattering techniques.

This book reflects the recent progress made in the field of scattering in polymers. A wide range of scattering studies on different polymer systems, including block copolymers, semicrystalline polymers, complex fluids, multicomponent systems, polymeric surfaces, and polymer processing are included, as well as new experimental techniques and theoretical treatments. This volume provides a comprehensive reference for those researchers who need to know how scattering techniques can be used to tackle different polymer problems, and is ideal for graduate polymer scientists studying scattering techniques.

We plan to study the effect of both oscillatory and steady state shear flow on the mesoscopic structure of polymer blends. A central feature of this proposal is the design and build of a rheometer for use with small angle neutron scattering. This will enable the simultaneous measurement, and hence correlation, of rheological properties and structure. It differs from existing facilities in that it is specifically aimed at viscoelastic materials with a high viscosity. We will study both polystyrene blended with is deuterated analogue, and blends of polystyrene/polyvinylmethylether and polyethyleneoxide/ polymethylmethacrylate. In each case both blend components will be highly entangled. We will meaure the anisotropy of the scattering pattern in the one phase region, and use this information to verify or otherwise recent theoretical predictions. We will also measure the structures that exist within the two-phase region, caused by shear induced phase separation. ...

Due to the large transmural variation in transmembrane potential following the application of strong electric shocks, it is thought that fluorescent photon scattering from depth plays a significant role in optical signal modulation at shock-end. For the first time, a model of photon scattering is used to accurately synthesize fluorescent signals over the irregular geometry of the rabbit ventricles following the application of such strong shocks. A bidomain representation of electrical activity is combined with finite element solutions to the photon diffusion equation, simulating both the excitation and emission processes, over an anatomically-based model of rabbit ventricular geometry and fiber orientation. Photon scattering from within a 3D volume beneath the epicardial optical recording site is shown to transduce differences in transmembrane potential within this volume through the myocardial wall. This leads directly to a significantly modulated optical signal response with respect to that predicted

a/LCI. a/LCI, which is outlined in detail in references ( 11, 12), obtains depth-resolved measurements of the far-field diffraction of a biological sample, which corresponds to a cell monolayer in the present study. Low coherence interferometry permits the rejection of multiply scattered light that can cause noise artifacts in the signal. The signal resulting from an a/LCI measurement is processed to isolate the scattering from individual cell nuclei and all smaller organelles in the ensemble while eliminating contributions from long range correlations within the monolayer ( 24). The processed nuclear scattering profile is then analyzed using an inverse light scattering analysis (ILSA) algorithm to determine the properties of the nucleus (shape, size, etc.). Traditional ILSA algorithms for analyzing scattering from biological samples have generally used Mie theory, a model of spherical scatterers; however, in the present study, the ILSA algorithm uses a T-matrix light scattering model ( 25), ...

Novel graft copolymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with N-vinylpyrrolidone (NVP) were designed and synthesized by the free radical copolymerization of DMAEMA with precursor polymers of vinyl-functionalized poly(N-vinylpyrrolidone) (PVP). The ability of the PVP- grafted copolymers to bind and condense DNA was confirmed by ethidium bromide displacement assay, agarose gel electrophoresis and transmission electron microscopy. The presence of PVP in the copolymers had a favorable effect on the biophysical properties of polymer/DNA complexes. Colloidal stable complexes obtained from the copolymer systems, were shown to be separate, uniformly spherical nanoparticles by transmission electron microscopy. The approximate diameter of the complexes was 150-200 nm, as determined by dynamic light scattering studies. These results confirm an important role played by the PVP grafts in producing compact stable DNA complexes. The ζ-potential measurements revealed that the incorporation of the ...

TY - JOUR. T1 - Vibronic coupling in the superoxide anion: The vibrational dependence of the photoelectron angular distribution. AU - Van Duzor, Matthew. AU - Mbaiwa, Foster. AU - Wei, Jie. AU - Singh, Tulsi. AU - Mabbs, Richard. AU - Sanov, Andrei. AU - Cavanagh, Steven. AU - Gibson, Stephen. AU - Lewis, Brenton. AU - Gascooke, Jason. PY - 2010/11/7. Y1 - 2010/11/7. N2 - We present a comprehensive photoelectron imaging study of theO 2(X2∑g, v′ =0-6) ←O 2 - (X2Πg, v″ =0) and O 2 (a 1Δg, v′=0-4)←O 2 -((X2Πg, v″ =0) photodetachment bands at wavelengths between 900 and 455 nm, examining the effect of vibronic coupling on the photoelectron angular distribution (PAD). This work extends the v′ =1-4 data for detachment into the ground electronic state, presented in a recent communication [R. Mabbs, F. Mbaiwa, J. Wei, M. Van Duzor, S. T. Gibson, S. J. Cavanagh, and B. R. Lewis, Phys. Rev. A 82, 011401(R) (2010)]. Measured vibronic intensities are compared to Franck-Condon predictions ...

We present a methodical study of grazing-incidence small-angle x-ray scattering performed in situ during pulsed-laser deposition of Pt on sapphire substrates. From measured two-dimensional intensity distributions in reciprocal space we calculated horizontal and vertical intensity projections and compare them to numerical simulations. The structure of the Pt layers was described using a simple Monte-Carlo model and the Ornstein-Zernicke theory with the Percus-Yevick approximation, and the scattering process was simulated using distorted-wave Born approximation. The validity of the structure models as well as the effect of the indirect scattering processes are discussed. From the comparison of the measured and simulated data we determined the lateral and vertical sizes of surface islands, the surface coverage, the island coalescence, as well as the thickness of the wetting layer at the substrate surface. We studied the time evolution of these parameters and their dependence on the substrate ...

Although I cannot say I completely grasp the underlying theory, the Bayesian approach to the Inverse Fourier Transformation of (isotropic) small-angle scattering patterns certainly appeals to me. The idea is that the small-angle scattering pattern can be transformed (back) into real-space, resulting in either a distance distribution function p(r), a correlation function gamma(r) (=r^2 p(r) ), or through double derivation of the result, into a chord length distribution (CLD). The Bayesian approach removes the user-defined input requirements of the standard IFT.. So what can you do with all this real-space information? Well, first of all, being in real space means that ones intuition can once more be applied (because intuition does not work in reciprocal space). For example: a maximum probability at a certain radius really may indicate that this is a characteristic length scale in the system. Secondly, the real-space p(r) may be a lot easier to fit than the scattering pattern itself, especially ...

In the present work two nuclei have been investigated by the elastic scattering of charged particles of spin 1/2 from spin 0 nuclei. In the first experiment protons were scattered from He4 yielding information on the compound nucleus Li5. A phase shift analysis of the angular distributions has been done. The results of experiments from 1 to 18 mev of proton bombarding energy have been collected, and the resulting phase shifts have been interpreted in the light of the dispersion theory. In the second experiment He3 nuclei were scattered from He 4 giving information about the compound nucleus Be7. The second excited state of Be7 has been investigated, and the level parameters have been determined. The non-resonant phase shifts show a somewhat anomalous behaviour in the energy range investigated, and these phase shifts have been qualitatively interpreted in terms of other levels in Be7. The phase shift analysis of these experiments has been done on an IBM 650 computer, and as a by-product of the ...

Description. Scattering is a very powerful tool to study the structure of polymers. Written by highly regarded and respected scientists in the field, this book presents the latest developments in the field of scattering in a uniform, systematic manner. This volume arms readers with both theoretical and experimental aspects of the intended area, offering much simplified theoretical explanations on the physics of scattering. The authors provide discussion on applications of experimental techniques. Han and Akcasu begin with a traditional treatment of light scattering from plane waves, followed by consistent application of density (in both real and Fourier space) correlation functions in both space and time. The authors do not distinguish among light, X-ray, and neutron, excepting their scattering length, q-range, coherence and detection differences. Readers can therefore concentrate on exactly the scattering tools they need to use, while theoretical explanation on the physics of scattering can be ...

TY - JOUR. T1 - Solution properties of capsular polysaccharides from Streptococcus pneumoniae. AU - Harding, Stephen E.. AU - Abdelhameed, Ali Saber. AU - Morris, Gordon A.. AU - Adams, Gary. AU - Laloux, Olivier. AU - Cerny, Louis. AU - Bonnier, Benjamin. AU - Duvivier, Pierre. AU - Conrath, Karel. AU - Lenfant, Christophe. PY - 2012/9/1. Y1 - 2012/9/1. N2 - Capsular polysaccharides from ten different serotypes of Streptococcus pneumoniae have been studied with regards their hydrodynamic properties in solution, namely their sedimentation coefficient and molar mass distributions, solution conformations and flexibilities (persistence lengths L p), important properties for the construction of polysaccharide and glycoconjugate vaccines. Sedimentation and molar mass distributions (obtained by sedimentation velocity and equilibrium analysis in the analytical ultracentrifuge supported by size exclusion chromatography coupled to multi-angle light scattering measurements) were generally unimodal, with ...

Efficiency of binary power cycles can be improved by expanding the hydrocarbon working fluids through two-phase region in a turbine and exiting at saturated or superheated condition. This improvement can be achieved if there is no condensation during the expansion or if there is condensation, the droplet size is extremely small. In order to verify this, a particle sizing technique for extremely small particles in flow is needed. In this study, a laser-based technique is developed by which it is possible to detect particles as small at ten angstroms in size. The basis of the technique is that particles of size less than one third of the wavelength of the incident radiation will scatter according to Rayleigh scattering theory. According to this theory, the intensity of the scattered light will be the same in the forward as well as in the backward directions. Therefore, measurement of the scattered intensity at two or three different angles will confirm the presence of Rayleigh scattering. The size ...

Small angle neutron scattering (SANS) has brought insight into how ions are transported at the nano level in stacked membranes of graphene, materials that have many unique properties. The research was aimed to develop graphene into a more versatile material.

D11 is the archetype of a long, pinhole geometry instrument for small angle neutron scattering (SANS), designed for the study of large scale structures in soft matter systems, chemistry, biology, solid state physics and materials science. This instrument was upgraded as a part of the ILLs Millennium Programme. ...

When neutron beams scatter at very low angles away from their original direction of travel, they are described as small angle scattering.. The scattering patterns contain information about the size and distribution of the scattering objects which can have sizes up to 500 nm.. Whenever you see halos surrounding the moon or sun, you are looking at small angle scattering. Ice crystals or water droplets in the atmosphere scatter the light into rings with distinct diameters depending on the crystal or droplet size. A wide range of sizes will cause the rings to interfere with one another, giving a diffuse, whitish glow, or aureole.. SANS is recognised as a powerful technique for determining microstructure in the dimension range of 1 to 500 nm. The LOQ SANS instrument at ISIS has been highly successful in pioneering the virtues of the white beam time-of flight method, the ability to access a wide range of scattering vectors, Q, (length scales) simultaneously with improved resolution. The experimental ...

The present study explores the potential use of asymmetrical flow field flow fractionation (aFlFFF) with a multidetection system for the study of metal-alginate interactions. aFlFFF, coupled on-line to a differential refractive index and seven angle laser light scattering detectors was used to provide information on the alginate size distributions. In parallel, the metal distributions of metal-alginate complexes were probed by aFlFFF-high resolution inductively coupled plasma-mass spectrometry. Average values and continuous distributions of molar masses, radiuses of gyration and hydrodynamic radiuses, which are critical for understanding the role of alginates as carriers of metal pollutants, were evaluated in presence of Pb or Cd and compared with those in metal-free solutions of alginate. The values of number average and weight average molar mass, weight average radius of gyration and shape factor for alginate were 150 and 188 kg mol(-1), 53 nm and 1.7, respectively. Alginate molar mass and ...

Cassini made a close flyby of Saturns moon Iapetus on Sept. 10, 2007, and the visual and infrared mapping spectrometer obtained these images during that event. These two images show a higher resolution version of the equatorial region shown in PIA10010. The equatorial region includes the equatorial bulge which shows no differences in these compositions compared to surrounding regions.. The color image on the right shows the results of mapping for three components of Iapetus surface: carbon dioxide that is trapped or adsorbed in the surface (red), water in the form of ice (green), and a newly-discovered effect due to trace amount of dark particles in the ice creating what scientists call Rayleigh scattering (blue). The Rayleigh scattering effect is the main reason why the Earths sky appears blue.. There is a complex transition zone from the dark region, on the right, which is high in carbon dioxide, to the more ice-rich region on the left. Some crater floors are filled with carbon dioxide-rich ...

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Abstract: Oligoadenylate synthetases (OASs) are a family of interferon-inducible enzymes that require double-stranded RNA (dsRNA) as a cofactor. Upon binding dsRNA, OAS undergoes a conformational change and is activated to polymerize ATP into 2′-5′-oligoadenylate chains. The OAS family consists of several isozymes, with unique domain organizations to potentially interact with dsRNA of variable length, providing diversity in viral RNA recognition. In addition, oligomerization of OAS isozymes, potentially OAS1 and OAS2, is hypothesized to be important for 2′-5′-oligoadenylate chain building. In this study, we present the solution conformation of dimeric human OAS2 using an integrated approach involving small-angle x-ray scattering, analytical ultracentrifugation, and dynamic light scattering techniques. We also demonstrate OAS2 dimerization using immunoprecipitation approaches in human cells. Whereas mutation of a key active-site aspartic acid residue prevents OAS2 activity, a C-terminal ...

Rayleigh scattering is a process in which electromagnetic radiation (including light) is scattered by a small spherical volume of variant refractive indexes, such as a particle, bubble, droplet, or even a density fluctuation. This effect was first modeled successfully by Lord Rayleigh, from whom it gets its name. In order for Rayleighs model to apply, the sphere must be much smaller in diameter than the wavelength (λ) of the scattered wave; typically the upper limit is taken to be about 1/10 the wavelength. In this size regime, the exact shape of the scattering center is usually not very significant and can often be treated as a sphere of equivalent volume. The inherent scattering that radiation undergoes passing through a pure gas is due to microscopic density fluctuations as the gas molecules move around, which are normally small enough in scale for Rayleighs model to apply. This scattering mechanism is the primary cause of the blue color of the Earths sky on a clear day, as the shorter ...

Optical clearing of mouse dermis by glycerol was tested by reflectance-mode confocal microscopy (rCSLM) using 488- nm light. The reflectance signal R(z) was acquired as a function of the depth of the focus (z) within the upper 100 μm of freshly excised mouse dermis. The results specify the scattering coefficient (μs [cm-1]) and the anisotropy of scattering (g [dimensionless]). The absorption is too low to exert an effect. The results, published in Samatham et al., Journal of Innovative Optical Health Sciences 2010, 3(3):183-188, described how the clearing effect of glycerol was to increase g toward nearly 1.0, while having only a modest effect on μs. In other words, glycerol caused light scattering to become very forward-directed, but did not strongly alter the number of scattering events per unit length of photon path. This paper discusses the possible mechanism of action that is responsible for this clearing effect ...

0055] In the external light extraction, an external scattering layer may be manufactured in a sheet shape and then is attached to the substrate external through a similar method of forming an MLA sheet. Or, an external scattering layer may be manufactured by coating a substrate with a manufactured solution and hardening the coated substrate. Since there is no color change and interference color according to a viewing angle in the external scattering layer and Lambertian distribution is maintained after light passes through a light scattering layer, this light extraction structure may be applicable to a white OLED lighting panel. However, if a light scattering layer becomes thicker and light scattering particles form a multi layered structure, scattering effect of a short wavelength becomes greater than that of a long wavelength so that a transmission color has yellowish red. This should be taken care of. In order to minimize a spectrum change due to a scattering effect difference according to a ...

The information determined relates to the particle size, shape, distribution and orientation, porosity, surface features and internal structure.. A SAXS sample requires very little preparation and results are representative of the bulk material. The scattered signal is typically recorded at diffraction angles of ,6° and the sample is positioned at a long distance from the detector. The measured scattered signals are accordingly extremely weak. For this reason, SAXS measurements benefit from the use of a high brilliance X-ray source such as the MetalJet, which makes weak scattering effects, stronger, more visible and more readily studied.. ...

The kinetics of kraft lignin (KL) aggregation at alkaline conditions was studied by quasi-elastic light scattering (QELS) and turbidity measurements. Stability ratios (W) for HL were obtained at 70 degreesC and various concentrations of sodium chloride. By analyzing the early-time evolution data of aggregate growth obtained from QELS, fractal dimensions of flocs formed in both reaction-limited cluster-cluster aggregation regimes and diffusion-limited cluster-cluster aggregation regimes were determined. Correlations between the fractal dimension and the W-ratio were found in accordance to recent studies of a system containing monodisperse polystyrene colloids. By cryogenic transmission electron microscopy, the fractality of KL aggregate structures in the system was also shown. It was seen from stability studies of KL solutions that the effects of specific co- and counterions follow the Hofmeister series. From the outcome of the investigation, different modes of aggregation occurring in a KL ...