Aberration-free three-dimensional multiphoton imaging of neuronal
... two-photon excitation of fluorescent indicators of neuronal activity have established themselves as the method of choice to monitor the activity in thin dendrites and large neuronal populations (1–6). Current technology, however, does not allow the spot of light to be scanned sufficiently fast in al ...
... two-photon excitation of fluorescent indicators of neuronal activity have established themselves as the method of choice to monitor the activity in thin dendrites and large neuronal populations (1–6). Current technology, however, does not allow the spot of light to be scanned sufficiently fast in al ...
Biomedical imaging in the undergraduate physics curriculum
... Fig. 3. D. Contrast In addition to resolution, an image must possess contrast. Contrast is a measure of the differences in luminance that provide gray-scale or color information in an image.6 Contrast formation differs from resolution in that it is dictated by properties of the sample as well as by ...
... Fig. 3. D. Contrast In addition to resolution, an image must possess contrast. Contrast is a measure of the differences in luminance that provide gray-scale or color information in an image.6 Contrast formation differs from resolution in that it is dictated by properties of the sample as well as by ...
Mole-Mass Conversions
... What is the representative particles for the following substances ? (atoms, molecules, formula units) a. Manganese ...
... What is the representative particles for the following substances ? (atoms, molecules, formula units) a. Manganese ...
Saturation
... through a gas with Maxwell-Boltzmann velocity distribution the laser frequency in the frame of the molecule is ' k v z With k v z fall within the linewidth ...
... through a gas with Maxwell-Boltzmann velocity distribution the laser frequency in the frame of the molecule is ' k v z With k v z fall within the linewidth ...
[pdf]
... spherical object2, the results presented here are useful because they are exact and enable rapid computations for signal-to-noise assessment over a broad range of experimental parameters. For example, the computation when analytic solutions are used for 100 arbitrary source–detector pairs in an infi ...
... spherical object2, the results presented here are useful because they are exact and enable rapid computations for signal-to-noise assessment over a broad range of experimental parameters. For example, the computation when analytic solutions are used for 100 arbitrary source–detector pairs in an infi ...
Introduction to colloid and sol-gel chemistry
... Total interface area of the colloidal dispersed particles is very large due to their submicroscopic size. The huge area-to-volume ratio determines specific properties and behavior of colloids. In other words, as in the colloids the amount of dispersed particles is very large, their overall surface i ...
... Total interface area of the colloidal dispersed particles is very large due to their submicroscopic size. The huge area-to-volume ratio determines specific properties and behavior of colloids. In other words, as in the colloids the amount of dispersed particles is very large, their overall surface i ...
Nonlinear photoacoustic spectroscopy of hemoglobin
... to heat. Subsequent thermoelastic expansion generates an acoustic wave, termed the PA wave.1,2 Detection of PA waves sequentially excited at multiple optical wavelengths provides quantitative information about the concentrations of multiple chromophores such as oxygenated and deoxygenated hemoglobin ...
... to heat. Subsequent thermoelastic expansion generates an acoustic wave, termed the PA wave.1,2 Detection of PA waves sequentially excited at multiple optical wavelengths provides quantitative information about the concentrations of multiple chromophores such as oxygenated and deoxygenated hemoglobin ...
Single-Molecule Fluorescence Resonance Energy Transfer
... them. A number of dyes are available in phosphoramidite form and can be readily incorporated during nucleic acid synthesis. Alternatively, amine-reactive dyes can be attached to an amino group introduced during synthesis. Then, dye-labeled nucleic acids can be purified from free dyes and unlabeled n ...
... them. A number of dyes are available in phosphoramidite form and can be readily incorporated during nucleic acid synthesis. Alternatively, amine-reactive dyes can be attached to an amino group introduced during synthesis. Then, dye-labeled nucleic acids can be purified from free dyes and unlabeled n ...
Quantitative evaluation of light microscopes based on image
... filters are used, each with a bandwidth of 10 nm. The center wavelengths of these filters are 400 nm, 500 nm, 600 nm, and 700 nm (Andover Corporation, Salem, NH, USA). 3. Procedures In this section the variety of test procedures that use digital image processing techniques will be described and the ...
... filters are used, each with a bandwidth of 10 nm. The center wavelengths of these filters are 400 nm, 500 nm, 600 nm, and 700 nm (Andover Corporation, Salem, NH, USA). 3. Procedures In this section the variety of test procedures that use digital image processing techniques will be described and the ...
PDF
... In the integrated imaging and manipulation setup, the same objective is used for optical trapping as well as fluorescence confocal microscopy. In both cases, the laser beams are focussed to a tiny region < 1μm3. A dichroic mirror (Chroma) is mounted in a rotating filter turret positioned below the m ...
... In the integrated imaging and manipulation setup, the same objective is used for optical trapping as well as fluorescence confocal microscopy. In both cases, the laser beams are focussed to a tiny region < 1μm3. A dichroic mirror (Chroma) is mounted in a rotating filter turret positioned below the m ...
Focusing of light through a stratified medium: a practical
... difference is that when using Eq. (21) with the Gibson and Lanni parameters, one computes the PSF in an absolute reference frame centered at the geometrical position of the focal point, while curves presented in Reference 10 are displayed with the distance of the last interface from the unaberrated ...
... difference is that when using Eq. (21) with the Gibson and Lanni parameters, one computes the PSF in an absolute reference frame centered at the geometrical position of the focal point, while curves presented in Reference 10 are displayed with the distance of the last interface from the unaberrated ...
Fluorescence Microscopy
... Initially, fluorescence microscopy was performed with transmitted light, but because the emitted fluorescence is weak in comparison to the excitation light, it was necessary to view the fluorescence with filters capable of blocking very bright transmitted excitation light. Overall, this scheme was not v ...
... Initially, fluorescence microscopy was performed with transmitted light, but because the emitted fluorescence is weak in comparison to the excitation light, it was necessary to view the fluorescence with filters capable of blocking very bright transmitted excitation light. Overall, this scheme was not v ...
Lab 1: Measurement
... Weighing a sample is often the first step in many quantitative analytical methods. An analytical balance measures masses to within 0.0001 g. Balances are sensitive to drafts, changes in temperature, or the vibrations caused by moving people. The balances are stored in a separate room to minimize the ...
... Weighing a sample is often the first step in many quantitative analytical methods. An analytical balance measures masses to within 0.0001 g. Balances are sensitive to drafts, changes in temperature, or the vibrations caused by moving people. The balances are stored in a separate room to minimize the ...
Concentration-dependent absorption and emission behaviour of
... The fluorescence spectra were measured using front-face illumination in a self-assembled spectrofluorimeter [28]. A tungsten lamp spectrally filtered with an interference filter centered at A =550 nm was used as excitation source. The backward emitted fluorescence light was collected, directed to a ...
... The fluorescence spectra were measured using front-face illumination in a self-assembled spectrofluorimeter [28]. A tungsten lamp spectrally filtered with an interference filter centered at A =550 nm was used as excitation source. The backward emitted fluorescence light was collected, directed to a ...
Measuring Human Chromosomes using Confocal microscopy
... Lensless imaging is a high resolution microscopy and is applied to such fields that face difficulties with optical imaging. The benefit of not using lens is that the resolution of the image depends only on the diffraction and dose limits. When coherent beam is scattered to an object, the resulted di ...
... Lensless imaging is a high resolution microscopy and is applied to such fields that face difficulties with optical imaging. The benefit of not using lens is that the resolution of the image depends only on the diffraction and dose limits. When coherent beam is scattered to an object, the resulted di ...
Chemical (Elemental) Analysis - Fritz-Haber
... Ø nonspecific absorptions from solid or liquid particles in the atomizer (e.g. light scatterring by liquid or solid ...
... Ø nonspecific absorptions from solid or liquid particles in the atomizer (e.g. light scatterring by liquid or solid ...
Correlation Effects in Two-Electron Model Atoms in Intense Laser
... spatial domain to permit the calculations to be made. In this Letter we show that an expansion of the twoelectron wave function into a sum of Slater determinants of one-electron orthonormal orbitals, as explained below, solves both of these problems. It provides a way to obtain two-electron wave fun ...
... spatial domain to permit the calculations to be made. In this Letter we show that an expansion of the twoelectron wave function into a sum of Slater determinants of one-electron orthonormal orbitals, as explained below, solves both of these problems. It provides a way to obtain two-electron wave fun ...
Sisay M THESIS - Addis Ababa University Institutional Repository
... with spatially varying directions of propagation. By inverting data on the exit ...
... with spatially varying directions of propagation. By inverting data on the exit ...
Temporal variation in cyanobacteria species composition and
... addition of nutrients and lake plankton, and observed succession from M. aeruginosa and A. issatschenkoi. Because we started the experiment in late August, water temperature was highest at the onset of the experiment and successively decreased during the experiment (data not shown). As A. issatschen ...
... addition of nutrients and lake plankton, and observed succession from M. aeruginosa and A. issatschenkoi. Because we started the experiment in late August, water temperature was highest at the onset of the experiment and successively decreased during the experiment (data not shown). As A. issatschen ...
Markov chain model in maximum-likelihood sequence detection for
... Abstract—In free-space optical communication links using intensity modulation and direct detection (IM/DD), atmospheric turbulence-induced intensity fluctuations can significantly impair link performance. Communication techniques can be applied to mitigate turbulence-induced intensity fluctuations ( ...
... Abstract—In free-space optical communication links using intensity modulation and direct detection (IM/DD), atmospheric turbulence-induced intensity fluctuations can significantly impair link performance. Communication techniques can be applied to mitigate turbulence-induced intensity fluctuations ( ...
Helical tractor beam: analytical solution of Rayleigh particle dynamics Luis Carretero, Pablo Acebal,
... 16. M. Nieto-Vesperinas, J. S??enz, R. Gomez-Medina, and L. Chantada, “Optical forces on small magnetodielectric particles,” Opt. Express 18, 11428–11443 (2010). 17. N. Wang, J. Chen, S. Liu, and Z. Lin, “Dynamical and phase-diagram study on stable optical pulling force in Bessel beams,” Phys. Rev. ...
... 16. M. Nieto-Vesperinas, J. S??enz, R. Gomez-Medina, and L. Chantada, “Optical forces on small magnetodielectric particles,” Opt. Express 18, 11428–11443 (2010). 17. N. Wang, J. Chen, S. Liu, and Z. Lin, “Dynamical and phase-diagram study on stable optical pulling force in Bessel beams,” Phys. Rev. ...
Single-shot measurement of a 52 fs pulse
... pulses. In the picosecond domain, streak cameras with 0.4-ps rise time exist, but they cannot be used for 100-fs pulses. At this time, there is much theorizing about new measurement systems for femtosecond pulses5 -7 but few experimental demonstrations of their capabilities. The problem is to transf ...
... pulses. In the picosecond domain, streak cameras with 0.4-ps rise time exist, but they cannot be used for 100-fs pulses. At this time, there is much theorizing about new measurement systems for femtosecond pulses5 -7 but few experimental demonstrations of their capabilities. The problem is to transf ...
Fundamental Limits in Confocal Microscopy
... than dye concentration. These variables include the local fluorescent decay time constant, which can depend strongly on the molecular environment, and local defocus effects that may affect the peak intensity in the focused spot and hence the degree of saturation. It follows from this last point that ...
... than dye concentration. These variables include the local fluorescent decay time constant, which can depend strongly on the molecular environment, and local defocus effects that may affect the peak intensity in the focused spot and hence the degree of saturation. It follows from this last point that ...
Correlated diffraction and fluorescence in the backscattering
... The “birdwings” comprise some of the largest butterflies on Earth 关1兴: the wingspan of some of them, such as Ornitopthera alexandrae, can reach 30 cm. The common name of these butterflies, “birdwings,” has most probably been coined after the visual appearance of their wings, where a particular patte ...
... The “birdwings” comprise some of the largest butterflies on Earth 关1兴: the wingspan of some of them, such as Ornitopthera alexandrae, can reach 30 cm. The common name of these butterflies, “birdwings,” has most probably been coined after the visual appearance of their wings, where a particular patte ...
Fluorescence correlation spectroscopy
Fluorescence correlation spectroscopy (FCS) is a correlation analysis of fluctuation of the fluorescence intensity. The analysis provides parameters of the physics under the fluctuations. One of the interesting applications of this is an analysis of the concentration fluctuations of fluorescent particles (molecules) in solution. In this application, the fluorescence emitted from a very tiny space in solution containing a small number of fluorescent particles (molecules) is observed. The fluorescence intensity is fluctuating due to Brownian motion of the particles. In other words, the number of the particles in the sub-space defined by the optical system is randomly changing around the average number. The analysis gives the average number of fluorescent particles and average diffusion time, when the particle is passing through the space. Eventually, both the concentration and size of the particle (molecule) are determined. Both parameters are important in biochemical research, biophysics, and chemistry.FCS is such a sensitive analytical tool because it observes a small number of molecules (nanomolar to picomolar concentrations) in a small volume (~1μm3). In contrast to other methods (such as HPLC analysis) FCS has no physical separation process; instead, it achieves its spatial resolution through its optics. Furthermore, FCS enables observation of fluorescence-tagged molecules in the biochemical pathway in intact living cells. This opens a new area, ""in situ or in vivo biochemistry"": tracing the biochemical pathway in intact cells and organs.Commonly, FCS is employed in the context of optical microscopy, in particular Confocal microscopy or two-photon excitation microscopy. In these techniques light is focused on a sample and the measured fluorescence intensity fluctuations (due to diffusion, physical or chemical reactions, aggregation, etc.) are analyzed using the temporal autocorrelation. Because the measured property is essentially related to the magnitude and/or the amount of fluctuations, there is an optimum measurement regime at the level when individual species enter or exit the observation volume (or turn on and off in the volume). When too many entities are measured at the same time the overall fluctuations are small in comparison to the total signal and may not be resolvable – in the other direction, if the individual fluctuation-events are too sparse in time, one measurement may take prohibitively too long. FCS is in a way the fluorescent counterpart to dynamic light scattering, which uses coherent light scattering, instead of (incoherent) fluorescence.When an appropriate model is known, FCS can be used to obtain quantitative information such as diffusion coefficients hydrodynamic radii average concentrations kinetic chemical reaction rates singlet-triplet dynamicsBecause fluorescent markers come in a variety of colors and can be specifically bound to a particular molecule (e.g. proteins, polymers, metal-complexes, etc.), it is possible to study the behavior of individual molecules (in rapid succession in composite solutions). With the development of sensitive detectors such as avalanche photodiodes the detection of the fluorescence signal coming from individual molecules in highly dilute samples has become practical. With this emerged the possibility to conduct FCS experiments in a wide variety of specimens, ranging from materials science to biology. The advent of engineered cells with genetically tagged proteins (like green fluorescent protein) has made FCS a common tool for studying molecular dynamics in living cells.