The propagation of light emitted by a linear light diffuser in a cylindrical hollow organ was investigated by means of the Monte Carlo (MC) method. The height and radius of the cavity, scattering (mu(s)) (or reduced scattering, mu'(s)) and absorption (mu(a)) coefficients, anisotropy (g), and refractive indices of the media ...

BACKGROUND: The objective of this study was to determine whether there are intrinsic differences in the light scattering properties of tumorigenic and nontumorigenic cells from a multistep carcinogenesis model. METHODS: Wavelength-dependent and polarization-dependent light scattering properties of cell suspensions were measured. RESULTS: Statistically significant differences were found between the tumorigenic ...

Eimeria minasensis n. sp. is described in the domestic goat Capra hircus from Brazil. Oocysts ellipsoidal are 35 x 24.5 (32-37.7 x 20.9-27.9) microns. Sporocysts elongate-ellipsoid are 15.2 x 9 (12.3-18.4 x 7.8-10.2) microns, with a Stieda body at the narrow end. Oocyst wall smooth and bilayered; outer layer about ...

A laboratory prototype of a novel experimental apparatus for the analysis of spherical and axisymmetric nonspherical particles in liquid suspensions has been developed. This apparatus determines shape, volume, and refractive index, and this is the main difference of this apparatus from commercially available particle analyzers. Characterization is based on the ...

Bacteriorhodopsin (BR) is a transmembrane protein in the purple membrane (PM) of Halobacterium salinarum. Its function as a light-driven proton pump is associated with a cycle of photointermediates which is strongly hydration-dependent. Using energy-resolved neutron scattering, we analyzed the thermal motions (in the nanosecond-to-picosecond time range) in PM at different ...

Submicroscopic gold particle suspensions scatter colored light when illuminated with white light, and we have observed that a light-scattering gold particle suspension has the same appearance as a fluorescing solution. Thus, when illuminated by a narrow beam of white light, a 40-nm gold sol displays a clear (not cloudy), green ...

OBJECTIVE: This study aimed to evaluate the extent of intraocular light scatter in patients with choroideremia. DESIGN: Prospective case-control study. PARTICIPANTS: Twelve male patients with choroideremia who had predominantly minimal or no posterior subcapsular cataract (PSC) lens opacities and visual acuities of 20/40 or better and 30 age-similar control subjects ...

To facilitate bioprosthetic heart valve design, especially in the use of novel antimineralization chemical technologies, a thorough understanding of the multiaxial mechanical properties of chemically treated bovine pericardium (BP) is needed. In this study, we utilized a small angle light scattering based tissue pre-sorting procedure to select BP specimens with ...

Dynamic light scattering was employed to investigate the behaviour of nucleating hen egg-white lysozyme solutions. For these studies we employed a novel fiber-optic based microprobe that suppresses multiple light scattering and contributions from large clusters in the spectra by backscattering detection. The time evolution of small lysozyme clusters is found ...

BACKGROUND: Luminosity and brightness of the organs viewed on the screen are important for orientation during teleoperating. They can impair the precision of our orientation ability. METHODS: The way in which organs scatter light during laparoscopic operation was detected and analyzed by means of reflection spectrophotometry with the Photoshop program ...

The unknown molecular weight and chemical structure of melanin place the study of these pigments outside the range of the classical biochemical techniques; thus in this paper the problem of characterizing these heterogeneous biopolymers was approached by means of light scattering techniques, static and dynamic. The static technique allowed us ...

We describe here an off-axis design for a 4.0-m astronomical telescope. We show that the geometric optical performance of this configuration can equal that of an on-axis conventional configuration while the diffractive performance fundamentally surpasses conventional telescopes because of the absence of pupil obstruction. The specific optical design described here ...

Real-time measurement capability of a frequency-modulated filtered light-scattering- (FM FLS) Doppler velocimeter has been demonstrated. Doppler-shifted light from a frequency-modulated Ti:sapphire laser scattered from a supersonic flow is imaged through a potassium vapor cell and is detected by FM spectroscopy. The FM signal is used in closed-loop feedback control of ...

The maximal area of complete scotopic spatial summation (Ricco's area) was determined for 50 subjects ranging in age from 19 to 87 yr. Increment thresholds were measured for 10-ms, 520-nm circular test lights of varying diameters that were superimposed and concentric with a 10 degrees, 640-nm circular background. The test ...

The acoustic scattering properties of live individual zooplankton from several gross anatomical groups have been investigated. The groups involve (1) euphausiids (Meganyctiphanes norvegica) whose bodies behave acoustically as a fluid material, (2) gastropods (Limacina retroversa) whose bodies include a hard elastic shell, and (3) siphonophores (Agalma okeni or elegans and ...

We developed a miniaturized, high-sensitivity camera that can be placed in areas of difficult access in freely behaving animals for neural tissue imaging. The device consists of a charged coupled device (CCD) chip, a coherent image conduit and miniature light emitting diodes (LEDs). An amplifier circuit is constructed on the ...

Phase analysis light scattering (PALS) was applied to characterize a high-frequency traveling-wave (TW) micropump. Field strength and frequency characteristics were measured for aqueous solutions up to 40 MHz and conductivities of 16 mS/m. The TW field was generated by an ultramicroelectrode array of intercastellated electrodes, which were driven by square-topped ...

Based on a multi-three-wave mixing model, we theoretically study the resistance against light-induced scattering in LiNbO(3):M (M=Mg(2+),Zn(2+),In(3+),Sc(3+)) crystals. We have simulated the intensity angular distribution of light-induced scatterings. We have also shown that the total light-induced scattering will be much less than 1% of the incident light intensity when the ...

In this paper, the molecular masses (M(r)s) of the complexes of monoclonal anti-BSA (antibody to bovine serum albumin) (clone: 33) and monomer BSA were determined on-line by using size-exclusion chromatography (SEC) coupled with a low-angle laser light-scattering (LALLS) detector and two concentration detectors, ultraviolet (UV) and refractive index (RI) (SEC-LALLS/UV/RI ...

A general-purpose, multifunction light-scattering instrument has been developed at the NASA Lewis Research Center for Space Shuttle and Space Station colloid crystallization and other microgravity experiments. For a single sample, the instrument can measure two-dimensional Bragg scattering from 0.5 degrees to 60 degrees , dynamic and static light scattering from ...

Multiple light scattering can be suppressed by slightly tilting two single-mode fibers viewing the same sample volume. The cross-correlation function of the two signals shows more or less contributions from single scattering, depending on the tilt angle. We show experimental results for polystyrene spheres at a scattering angle of 90 ...

It is demonstrated that light scattering from surface waves on a vertical liquid layer can be used for the determination of surface tension and kinematic viscosity of the liquid under investigation. In contrast to usual approaches of surface light scattering, a setup is described that enables measurements with the same ...

A mathematical model to estimate the solar irradiance profile and average light intensity inside a tubular photobioreactor under outdoor conditions is proposed, requiring only geographic, geometric, and solar position parameters. First, the length of the path into the culture traveled by any direct or disperse ray of light was calculated ...

OBJECTIVES: To show experimentally and clinically that information of blood circulation patterns can be obtained through dentin and enamel by means of reflected light. STUDY DESIGN: Several different experimental techniques were developed in vitro leading up to in vivo tests. RESULTS: Pulsatile information of back-scattered light at 560 nm was ...

We present measurements of second-harmonic generation with zinc-sulfide thin films. Both scattered light and specular light are investigated in linear optics as well as in second-harmonic generation. We show that second-harmonic generation is a powerful tool for understanding the nonlinear properties of thin films; it allows the study of the ...

The noninvasive measurement of variations in absorption that are due to changes in concentrations of biochemically relevant compounds in tissue is important in many clinical settings. One problem with such measurements is that the path length traveled by the collected light through the tissue depends on the scattering properties of ...

Speckle patterns in the light field scattered from the rough surface of a cylindrical object are experimentally studied. The light speckles are elongated in the direction normal to the cylinder axis. A theoretical model explains the main features of the scattered light field. The dimensions of light speckles depend on ...

The point statistics of light scattered from structured, incoherent illumination of a random and fluctuating population of identical scatterers are derived. Theoretical predictions for a two-beam illumination pattern in which the relative beam intensity is modulated are compared with computer simulations and experiments performed by illumination of a rotating mask ...

The effect of changing growth conditions on the diameter of rod-shaped bacteria was studied in vivo with the use of polarized light scattering. The value of a ratio of scattering matrix elements was measured as a function of scattering angle at various times after nutritional "upshift" for two strains of ...

Perturbation theory is used to compute the angular-intensity correlation function C(q, k|q(?), k(?)) = ?[I(q|k) - ?I(q|k)?][I(q(?)|k(?)) - ?I(q(?)|k(?))]? for p-polarized light scattered from a weakly rough, one-dimensional random metal surface. I(q|k) is the squared modulus of the scattering matrix for the system, and q , q(?) and k , ...

We study and analyze properties underlying the visual appearance of materials such as the surface bidirectional reflection distribution function and texture. The spatial distribution of scattered light in relation to the incident light determines the surface appearance and can be partly specified by the bidirectional reflection distribution function, which is ...

PURPOSE: To determine quantitatively dependence on the wavelength and angle, as a function of depth, of light scattering in the human lens. To compare the result for forward directions with psychophysical data. To derive candidate particle distributions that might be responsible for nuclear light scattering as significant in the psychophysical ...

Two constructs of transgenic mice, TG61 and TG72, containing the HIV-1 protease linked to the lens alpha A-crystallin promoter develop cataract. The TG61 construct develop cataract in utero, while the TG72 construct exhibit frank opacities on the 24th day (homozygotes) and 26th day (hemizygotes) post natum. Polarized light scattering measurements ...

The instruments clinically available for the diagnosis of approximal caries lesions are inadequate to detect lesions early and quantitatively. The aim of this study was to investigate whether wavelength-dependent light scattering and absorption of carious tissues may be utilized for the quantitative diagnosis of these small approximal caries lesions. Seventeen ...

Two versions of an anti-Stokes stimulated Raman scattering (SRS) experiment are presented, one with narrow-band light, the other with broadband light. The interferograms exhibit, at optical periods, alternation between complete signal extinction and high signal intensity with much higher contrast than seen in ordinary linear interferometry. Furthermore, for broadband excitation, ...

PURPOSE: To determine contributions of molecular scattering elements to the increase with age in the light scattered from the human ocular lens in vivo. METHODS: We used quasielastic light scattering to measure autocorrelation functions of the intensity of light scattered in vivo from three locations (anterior, nuclear and posterior) along ...

A new nonintrusive velocimetry diagnostic that combines the sensitivity of frequency-modulated (FM) absorption spectroscopy techniques and the spectral discrimination afforded by atomic-vapor absorption filters is presented. Doppler-shifted light from a FM Ti:sapphire laser scattered from a supersonic flow is imaged through a potassium-vapor cell and is detected by FM spectroscopy. ...

In recent years, time-resolved spectroscopy systems using near infrared pulsed laser have been applied to develop optical computed tomography. We applied this technique to measure the optical properties of osseous tissues. First, we gradually demineralized 10 mm blocks of bovine trabecular bone with EDTA, maintaining the absorption characteristics and structure ...

Optical methods assess different types of light tissue interactions such as light absorption, fluorescence, phosphoresence, scattering, and Doppler shift. In this article, it is reviewed how these different types of light-tissue interactions can be measured and how these measurements can be related to brain function. Based on these considerations, a ...

BACKGROUND AND OBJECTIVE: Whole bladder wall photodynamic therapy (PDT) is sometimes performed with a light scattering medium in the bladder, as it is assumed that this will promote a more uniform illumination of the bladder wall. The influence of eccentric placement of an isotropic light emitting diffuser on the homogeneity ...

We present a rigorous numerical simulation analysis of the second-harmonic generation of p-polarized light in reflection from a one-dimensional, randomly rough, metal surface when the plane of incidence is perpendicular to the generators of the surface. When the incident light cannot couple to surface electromagnetic waves supported by the metal ...

The dominant wavelength shift of 16 color filters is presented for a ±1% theoretical change in spectral centering and compared with the threshold-perceived color difference (dominant wavelength). The resulting change in dominant wavelength exceeds a threshold limit of a just-noticed color difference for some filters. Spectral-centering tolerance limits are given ...

PURPOSE: To make serial measurements of corneal haze and microscopic anatomy after photorefractive keratectomy (PRK) and compare the results with visual function measured at the same time points in the same single group of human subjects. METHODS: Ten patients underwent -6.00-diopter, 6-mm PRK. The patients were reviewed frequently for 12 ...

The image of a distant unresolved point (point image or PI) and modulation transfer function (MTF) of the eye and lens of the trout were recorded with high spatial (0.3 micron) and dynamic (4096 grey levels) resolution for various entrance aperture sizes and focal positions in monochromatic light, and in ...

One can apply two-tone frequency modulation spectroscopy techniques to the detection of gas-phase species by using laser light scattered from hard targets. High sensitivities are demonstrated, with a minimum detectable absorption of 10(-4) possible with a simple apparatus. The effects of laser speckle on the FM signal are described, and ...

Early detection of a caries lesion would enable the dentist, by using effective prophylactic measures, to enhance remineralization and conservation of the tooth substance rather than restoration of the dentition. The presently-used diagnostic methods of detecting early lesions require visual observation. Reflected light is used to detect changes in color, ...

Miniature light detectors with isotropic response (isotropic light probes) permit quantitative measurement of light energy fluence rates in turbid media such as biological tissues. These isotropic probes are, for example, applied in photodynamic therapy to correlate light fluence in tissue with (tumour) tissue response, in vitro and in vivo. After ...

The holographic first-arriving-light method in combination with the speckle differencing method is used to provide resolution-enhanced detection of moving objects embedded in scattering media. Results show that the first-arriving-light technique provides significant resolution improvements over standard speckle differencing.

The distribution of the light emitted by linear light diffusers commonly employed in photodynamic therapy (PDT) has been investigated. A device is presented which measures the angular distribution of the exiting light at each point of the diffuser. With these data the fluence rate in air or in a cavity ...

PURPOSE: To determine quantitatively forward light scattering in the human lens as a function of depth. To use this to explain the psychophysical result, verified earlier in vitro, showing total light scattering in the human lens to decrease with scattering angle according to an approximate power law (power -2). METHODS: ...