The voltage sensitivity of the fluorescent styrylpyridinium dye RH421 has been investigated in dimyristoylphosphatidylcholine vesicles by inducing an intramembrane electric field through the binding of the hydrophobic ion tetraphenylborate (TPB). To assess the probability of electrochromic and solvatochromic mechanisms for the ...

Styryl voltage-sensitive dyes (e.g., di-4-ANEPPS) have been widely and successfully used as probes for mapping membrane potential changes in cardiac cells and tissues. However, their utility has been somewhat limited because their excitation wavelengths have been restricted to the 450- to 550-nm range. Longer excitation/emission wavelength probes can ...

Voltage sensitive fluorescent dyes have long been used to measure physiological voltages in live cell cultures. However dyes suffer from poor contrast and limited recording duration due to photobleaching. A photostable voltage sensitive cellular label, such as a noble metal ...

-Sensitive Dye Signals The top panels illustrate the signals from dif- ferent experiments using the red dye RH but with the heartbeat signal (blank) subtracted. Note the large heartbeat artifact with the red dye at the time at High Neurotechnique Spatial and Temporal Resolution with Novel Blue Voltage-Sensitive ...

Optical recording of action potentials in individual neurons requires cell-selective targeting with a fluorescent, voltage-sensitive probe. We report on a new labeling system that takes advantage of recent developments in prodrug-based chemistry and allows for the targeting of a lipophilic dye into the plasma membrane of genetically specified cells. With ...

Long wavelength voltage-sensitive dyes (VSDs) called Pittsburgh (PGH) dyes were recently synthesized by coupling various heterocyclic groups to a styryl-thiophene intermediate forming extended, partially rigidized chromophores. Unlike most styryl VSDs, dyes with a sulfonic acid anchor directly attached to the ...

Fast responding voltage sensitive dyes, RH421 and di-4-ASPBS, were used to study the electrogenic properties of plant plasma membrane proton pumps on sealed plasma membrane vesicles extracted by two-phase partitioning from Beta vulgaris and Avena sativa cv Swan root material. Fluorescence spectroscopy in the presence of the ...

Voltage-sensitive dye imaging of neurons is a key methodology for the understanding of how neuronal networks are organised and how the simultaneous activity of participating neurons leads to the emergence of the integral functionality of the network. Here we present the methodology of application of this technique to identified pattern generating neurons ...

We present a novel voltage-sensitive hemicyanine dye ANNINE-6plus and describe its synthesis, its properties and its voltage-sensitivity in neurons. The dye ANNINE-6plus is a salt with a double positively charged chromophore and two bromide counterions. It is derived from the zwitterionic dye ...

Imaging activity of neurons in intact brain tissue was conceived several decades ago and, after many years of development, voltage-sensitive dyes now offer the highest spatial and temporal resolution for imaging neuronal functions in the living brain. Further progress in this field is expected from the emergent development of genetically encoded ...

This study investigated the absorption spectrum and the fluorescence spectrum of rabbit hearts stained with the voltage sensitive dye (di-4-ANEPPS). The results suggested that the optical absorption of tissue with the dye was higher than that of the control group, and there were significant differences between the ...

Nonlinear optical phenomena, such as two-photon fluorescence (2PF) and second harmonic generation (SHG), in combination with voltage sensitive dyes, can be used to acquire high-resolution spatio temporal maps of electrical activity in excitable cells and tissue. Developments in 1064-nm fiber laser technology have simplified the ...

... Abstract : Irradiation of ethanol solutions of coumarin laser dye lasers produces products which absorb at the lasing wavelength. ...

Physiological activity of the turtle cerebellar cortex (Cb), maintained in vitro, was recorded during microstimulation of inferior olive (IO). Previous single-electrode responses to such stimulation showed similar latencies across a limited region of Cb, yet those recordings lacked spatial and temporal resolution and the recording depth was variable. The topography and timing of those responses ...

Physiological activity of the turtle cerebellar cortex (Cb), maintained in vitro, was recorded during microstimulation of inferior olive (IO). Previous single-electrode responses to such stimulation showed similar latencies across a limited region of Cb, yet those recordings lacked spatial and temporal resolution and the recording depth was variable. The topography and timing of those responses ...

The natural linewidths of a laser with a saturable absorber and of a dye laser have been calculated using a Fokker-Planck approach.

In the presence of 4-aminopyridine (4-AP) and excitatory amino acid receptor blockers, GABAergic networks in the neocortex give rise to large spontaneous GABA-mediated depolarizations. We used voltage-sensitive dye techniques to explore the network properties of depolarizing GABA responses. Voltage-sensitive dye ...

... CONSIDERATION IS GIVEN TO THE SPECIFICATION OF THE VOLTAGE SENSITIVITY OF PIEZOELECTRIC POLYMER HYDROPHONES, AND A ...

FIGURE 1. Voltage-sensitive optical reporters. A: in fast VSDs, the transmembrane electric field affects the dye molecule directly. B: in two-component VSDs, changes in membrane potential cause the mobile dye molecule to translocate from one leaflet of the membrane to the other. This alters the distance between the two ...

The Retzius neuron from the leech, growing in culture on the plant lectin concanavalin A as substrate, produces broad flat growth cones and thick bundles of processes. The same cell extends fine straight processes with numerous branches when grown on a laminin-like substrate extracted from leech central nervous system extracellular matrix, referred to as "leech laminin extract." Cells growing on ...

A rhodamine 6G-DODCl dye solution was used as the gain medium and the saturable absorber was contained in a variable-gap dye cell in contact with a high reflectivity mirror.(AIP)

Transmembrane potentials appear to be cell state sensitive characteristics and can give information about cell damage initial stage. Photodynamic action of the photosensitizer chlorin e6 on plasmatic and mitochondrial membrane potentials of the rat thymus lymphocytes was studied using voltage-sensitive dye rhodamine 6G. It has been revealed that ...

for nine voltage-sensitive dyes in a solvent, octanol, intended to simulate the membrane environment wavelengths ranging from 790 to 960 nm. We used octanol as a solvent to approximate the environ- ment. (1978) Absorption and emission wavelengths are experimentally measured values in octanol. a Eastman

preparation; voltage-sensitive dye; radio-frequency ablation; atrial arrhythmia; porcine cardiac model. Atrial- dure on beating heart using bipolar radiofrequency ablation: A feasibility study in animals," Ann. Tho ABLATION LINES JENNIFER D. SIMONOTTO School of Computing Science, Claremont Tower, Newcastle University

Visual stimuli of short duration seem to persist longer after the stimulus offset than stimuli of longer duration. This visual persistence must have a physiological explanation. In ferrets exposed to stimuli of different durations we measured the relative changes in the membrane potentials with a voltage sensitive dye and the action ...

Optical imaging being one of the cutting-edge methods for the investigation of neural activity, it is very important to understand the mechanisms of how dye molecules work and the range of side effects that they may induce. In particular, it is very important to reveal potential toxic effects and effects impairing the functioning of the investigated neural system. Here, we ...

Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. This results in attenuation of dye laser output. Modes of degradation of coumarin dye lasers under both anaerobic and aerobic conditions were determined...

... Pagination or Media Count : 9. Abstract : Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. ...

... Pagination or Media Count : 7. Abstract : Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. ...

Phosphodiesterase type 5 (PDE5) acts specifically on cyclic guanosine monophosphate (cGMP) and terminates cGMP-mediated signalling. PDE5 has a well established role in vascular smooth muscle, where specific inhibitors of PDE5 such as sildenafil correct erectile dysfunction by augmenting cGMP-mediated vascular relaxation. However, the role of PDE5 outside of the vasculature has received little ...

... was to develop saturable absorber materials for Q-switching neodymium lasers emitting at ... In addition to the above tests, this dye solution was also ...

In many neurophysiological studies it is desirable to simultaneously record the activity of a large number of neurons. This is particularly true in the study of vertebrate motor systems that generate rhythmic behaviors, such as the pattern generator for locomotion in vertebrate spinal cord. Optical imaging of neurons labeled with appropriate fluorescent dyes, in which ...

The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of ...

Recently, non-invasive optical methods to monitor transmembrane electrical potential using voltage sensitive dyes have been applied widely in the studies of normal and pathological heart rhythms and defibrillation. In the present paper, the authors measured the excitation and the emission spectra of the voltage-sensitive ...

Perilesion depolarisations, whether transient anoxic depolarisation (AD) or spreading depression (SD), occur in stroke models and in patients with acute brain ischaemia, but their contribution to lesion progression remains unclear. As these phenomena correspond to waves of cellular depolarisation, we have developed a technique for their live imaging with a fluorescent ...

... X is the volume fraction crystallinity, A is the crystalline ... RG Snyder, Am ... the abs~orption or fluorescence bjy dyes which are absorbed by amorphous ...

... time scale of absorbing transient species such as excited singlet states and excited triplet states of conjugated organic molecules and dyes, the ...

The laser behavior of the Cresyl Violet-Rhodamine 6G dye system is studied by measurements of the small-signal gain spectra for various dye mixtures and pump powers. It is found that most of the pump power absorbed by the Rhodamine 6G is transferred to th...

We measured birefringence, 90 degree scattered light, and voltage sensitive dye changes from lobster walking leg nerves. Systematic application of key chemical agents revealed separate cellular mechanisms underlying fast optical signals. Each agent exhibited mixed effects, some having a greater effect on cellular swelling and ...

The electrical sheet resistance between living cells grown on planar electronic contacts of semiconductors or metals is a crucial parameter for bioelectronic devices. It determines the strength of electrical signal transduction from cells to chips and from chips to cells. We measured the sheet resistance by applying AC voltage to oxidized silicon chips and by imaging the voltage change across the ...

Introduction Optical measurements are ideal for observing neuronal activity in many neurons simultaneously We are using Fluorescence Resonance Energy Transfer (FRET) voltage-sensitive dyes (VSDs), which offer high sensitivity (Cacciatore et al 1999, Gonz lez & Tsien 1997) We have identified a novel follower of cell Tr2, a swim-terminating neuron This ...

The bibliography contains citations concerning the treatment and reuse of textile industry effluents containing dyes. The citations explore bacteria that absorb dyes, neutralization of dye effluents, decolorization by ozonization or ultraviolet radiation, flocculation treatment, and dye ...

The bibliography contains citations concerning the treatment and reuse of textile industry effluents containing dyes. The citations explore bacteria that absorb dyes, neutralization of dye effluents, decolorization by ozonization or ultraviolet radiation, flocculation treatment, and dye ...

The bibliography contains citations concerning the treatment and reuse of textile industry effluents containing dyes. The citations explore bacteria that absorb dyes, neutralization of dye effluents, color removal by ozonization and by treatment with manganese solid waste, flocculation treatment, and ...

Given the appropriate multicell electrophysiological techniques, small networks of cultured neurons (microcultures) are well suited to long-term studies of synaptic plasticity. To this end, we have developed an apparatus for optical recording from cultured vertebrate neurons using voltage-sensitive fluorescent dyes (Chien, C.-B., and J. Pine. 1991. J. ...

Early in cardiogenesis, heart primordia are brought together at the midline and fuse with each other progressively caudally-- this results in the formation of the primitive tubular heart which begins beating spontaneously at the middle period of the 9-somite developmental stage in the chick embryo. However, in these very early stages of development, the myocardial cells are small and technically ...

Intensity correlation measurements of pulse widths are reported for a sheet-flow rhodamine dye laser mode locked by synchronous gain modulation by a pulsed 2-W argon laser. For pump pulses 1 to 2-ns long, the minimum dye pulse width obtained is 50 ps. The dye-laser outputs in this pump pulse regime are discussed as a function ...

Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. This results in attenuation of dye laser output. Modes of degradation of coumarin dye lasers under both anaerobic and aerobic conditions were determined and methods of stabilization of dye ...

The nonuniform heating in flashlamp pumped dye lasers forms refractive index gradients in the dye solution. These gradients distort the wavefront of the laser beam resulting in limited output power, limited pulse repetition rate, and limited attainable linewidth. The theorectical bases for using uv absorbers and wavelength shifters to ...

The J-aggregates and the photosensitive properties of two kinds of mixed cyanine dye and the corresponding independent cyanine dyes absorbed on AgBr cubic microcrystal were investigated. The reflection spectra of the J-aggregates of the mixed cyanine dyes and the corresponding independent cyanine ...

Irradiation of ethanol solutions of coumarin laser dye lasers produces products which absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. A major photoprocess which produces material which absorbs at the lasing wavelength is ...

We carried out experiments to monitor optically the generation and spread of action potentials and subthreshold potentials in the processes of individual neurons in ganglia of the snail, Helix aspersa. The neurons were selectively stained by intracellular pressure injection of voltage-sensitive dyes. Optical signals were detected by a system for fast, multiple-site optical ...

Membrane potential measurements using voltage-sensitive dyes (VSDs) have made important contributions to our understanding of electrophysiological properties of multi-cellular systems. Here, we report the development of long wavelength VSDs designed to record cardiac action potentials (APs) from deeper layers in the heart. The emission spectrum of styryl ...

Mode locking of an argon laser by a dye saturable absorber was proposed and implemented. In addition to passive mode locking, double mode locking of the system was observed. In this case the dye was used also as an active medium subjected to synchronized pumping.

The effects of gamma radiation on Methylene Blue, Fluorescein, Rhodamine B, Fast Red S, and Brilliant Green dyes absorbed in Corning thirsty glass (code 7930) are presented. The optical absorbency follows Beer's law with radiation dose to 10/sup 9/ erg gm/sup -1/ carbon. The absorption of dyes in ...

Cyanine dyes are used as the donor fluorophore in energy transfer labels in which light energy is absorbed by a donor fluorophore and transferred to an acceptor fluorophore which responds to the transfer by emitting fluorescent light for detection. The cyanine dyes impart an unusually high sensitivity to the labels thereby improving ...

Cyanine dyes are used as the donor fluorophore in energy transfer labels in which light energy is absorbed by a donor fluorophore and transferred to an acceptor fluorophore which responds to the transfer by emitting fluorescent light for detection. The cyanine dyes impart an unusually high sensitivity to the labels thereby improving ...

Coumarin laser dyes are widely used in dye lasers for the generation of tunable laser light in the blue-green spectral region. As in the case with most laser dyes, coumarin dyes undergo photochemical reactions that interfere with simulated emission and result in loss of laser power output. This thesis describes the ...

Chirality can produce novel non-linear optical effects that may form the basis for new imaging contrast agents. In this paper we developed a new chiral chromophore 2, which is the dimer of a known voltage sensitive dye, monomer 1, with the chirality originating from the twisted orientation between two subunits. Racemic dimer and ...

Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained ...

Voltage-sensitive dye (VSD) imaging became a powerful tool to detect neural activity in the enteric nervous system, including its routine use in submucous neurons in freshly dissected human tissue. However, VSD imaging of human myenteric neurons remained a challenge because of limited visibility of the ganglia and dye accessibility. We ...

Partition constants for the oxacyanine dyes between water and nitrobenzene were determined using their absorbance and fluorescence properties. From these values the standard potential of transfer for a group of oxacyanine dye cations was calculated. Sever...

, Ecient ZnO Nanowire Solid-State Dye-Sensitized Solar Cells Using Organic Dyes and Core, SnO2-Based Dye-Sensitized Hybrid Solar Cells Exhibiting Near Unity Absorbed Photon. Wiesner, U. Steiner, and H. J. Snaith, Monolithic route to ecient dye-sensitized solar cells employing

with the absorbing dye Indocyanine green. and then illuminating the located at the origin is of the form sphere. The contours are shown on 20 intervals. (b) Indocyanine green absorption (solid line) and emission (broken line sterile Indocyanine green dye for this (broken lines). Two spectral filters centered on work. 2

This invention relates generally to nuclear radiation dosimetry, and more particularly to a radiochromic leuko dye dosimeter constructed and arranged to measure absorbed radiation doses, such as gamma rays, X-rays and fast neutrons, in real time; viz., as...

Passive mode locking of dye lasers is studied with the inclusion of the relaxation times. An equation derived for the integrated gain coefficient is used to explain the shortening mechanism in the long pulse stage in which gain saturation is shown to have an emphasized role in the compression of the trailing edge. (AIP)

The adsorption spectra of the laser-active dyes rhodamine B, rhodamine 6G and acridine red in aqueous, ethanolic and EPA solutions were studied as a function of concentration and temperature. The observed absorbance of the aqueous solutions of rhodamine B...

The phenomenon of non-additivity of spectral absorbance values was explored for a selected group of direct azo dyestuffs. Whereas previous investigations have been restricted to studies of a single dye which usually does not obey Beer's law or for dye mix...

In CNS neurons most of synaptic integration takes place in thin dendritic branches that are difficult to study with conventional physiological recording techniques (electrodes). When cellular compartments are too small, or too many, for electrode recordings, optical methods bring considerable advantages. Here we focused our experimental effort on the development and utilization of new kinds of ...

Passive mode locking of a cw Rhodamine 700 dye laser is reported for the first time to our knowledge. By using two saturable absorber dyes, DOTCI and HITCI, continuous-output trains of subpicosecond pulses have been obtained in the 727--740- and 762--778-nm spectral regions, respectively. By the addition of a fast-recovery-time ...

... Report Date : 05 AUG 1997. ... A significant enhancement of the SHG signal when the dyes are absorbed to colloidal silver has been demonstrated ...

... absorber based on a polymethine dye in a polyurethane matrix with ... generation (pulses with several tens of nanoseconds) � by self-Q-switching. ...

An optical element for filtering infrared light for use in a radiometer is disclosed wherein at least one metalorganic infrared absorbing dye is at least partially dissolved homogeniously throughout a molded optical plastic.

media for solar pumping have been identified and investigated i n the program. ..... a solar-pumped dye laser (like our laboratory system) in space. ...

A non-bleachable liquid absorber for high power laser apodizers which utilizes an annular liquid chamber filled with a dye solution composed of copper nitrate in dimethyl sulfoxide and water.

... methods of soil application of termiticides to prevent structural infestation. The breakthrough of bromide and fluorescein in column eluates were measured. The absorbance of fluorescein at ... ...

... dipped into organic dyes which absorb into the porous anodic coating. ... The dark black lines shown in Figure 16 were ... Multiple wire colors were ...

Oct 3, 2007 ... Bench-Top Antigen-Detection Technique Developed That Utilizes Nanofiltration and Fluorescent Dyes Which Emit and Absorb Light in the Near ...

Mar 1, 2011 ... Bench-Top Antigen Detection Technique that Utilizes Nanofiltration and Fluorescent Dyes which Emit and Absorb Light in the Near Infrared ...

Dithiene complexes are promising candidates for dye 'Q' switches functioning as saturable absorbers operating at two microns. Although these compounds are not commercially available, similar compounds have been prepared. The purpose of this contract was t...

Initial studies have been designed to provide fundamental information on both the nature of photoreactions in microemulsions and the utility of these media as solvents for absorbers of solar energy. We have investigated the photoreduction of absorbed dye ...

Studies designed to provide fundamental information on both the nature of photoreactions in microemulsions and the utility of these media as solvents for absorbers of solar energy were conducted. As a test system, the photoreduction of absorbed dye (princ...

Initial studies were designed to provide fundamental information on both the nature of photoreactions in microemulsions and the utility of these media as solvents for absorbers of solar energy. As a test system, the photoreduction of absorbed dye (methyl ...

There has been much interest in the development of two-photon absorbing materials and many efforts to understand the nonlinear absorption properties of these dyes, but this area is still not well understood. A computational model has been developed in our...

Coumarin laser dyes upon excitation degrade to produce products that absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. The roles of singlet oxygen and excitation intensity on dye degradation were explored. Singlet oxygen is formed but its ...

The equilibrium reactions of the metallochromic indicator dye Antipyrylazo III with calcium at physiological ionic strength have been investigated spectrophotometrically. Dye absorbance as a function of wavelength was measured at various total dye and calcium concentrations. Analysis of the ...

Cortical spreading depression (i.e. waves of cellular depolarization, CSD) causes the aura symptoms in classical migraine, and may contribute to delayed cellular damage after an ischemic or traumatic insult to the brain. In the latter cases, secondary neuronal injury may be worsened by some of the cerebral blood flow (CBF) changes that are associated with CSD. Here, we describe a new method for ...

In cardiac tissue, during partial blockade of the membrane sodium channels, or at high frequencies of excitation, inexcitable obstacles with sharp edges may destabilize the propagation of electrical excitation waves, causing the formation of self-sustained vortices and turbulent cardiac electrical activity. The formation of such vortices, which visually resembles vortex shedding in hydrodynamic ...

We examined activity fluctuations as ongoing and spontaneous activities that were recorded with voltage sensitive dye imaging in the auditory cortex of guinea pigs. We investigated whether such activities demonstrated spatial coherence, which represents the cortical functional organization. We used independent component analysis to ...

Several physical phenomena accompany the firing of electrical impulses by axons. Some of these, such as the microscopic swelling of axons, alter the transmission of light through axons. This produces what are called "intrinsic optical signals" because optical methods can be used to see axons fire without adding voltage-sensitive dyes or using electronic ...

Several physical phenomena accompany the firing of electrical impulses by axons. Some of these, such as the microscopic swelling of axons, alter the transmission of light through axons. This produces what are called “intrinsic optical signals” because optical methods can be used to see axons fire without adding voltage-sensitive dyes or ...

Little is known about the functional role of axotomized cortical neurons that survive spinal cord injury. Large thoracic spinal cord injuries in adult rats result in impairments of hindlimb function. Using retrograde tracers, we found that axotomized corticospinal axons from the hindlimb sensorimotor cortex sprouted in the cervical spinal cord. Mapping of these neurons revealed the emergence of a ...

We used in vivo voltage-sensitive dye optical imaging to examine the cortical representation of interaural time difference (ITD), which is believed to be involved in sound source localization. We found that acoustic stimuli with dissimilar ITD activate various localized domains in the auditory cortex. The main loci of the activation pattern shift up to ...

Intramyocardial reentry is implicated as a primary cause of the most deadly cardiac arrhythmias known as polymorphic ventricular tachycardia and ventricular fibrillation. However, the mechanisms involved in the triggering of such reentry and controlling its subsequent dynamics remain poorly understood. One of the major obstacles has been a lack of adequate tools that would enable 3D imaging of ...

Voltage-sensitive dye imaging (VSDI) allows population patterns of cortical activity to be recorded with high temporal resolution, and recent findings ascribe potential significance to these spatial propagation patterns - both for normal cortical processing and in pathologies such as epilepsy. However, analysis of these spatiotemporal patterns has been ...

Many vital processes depend on the generation, changes, and conduction of cellular transmembrane potentials. Optical monitoring systems are well suited to detect such cellular electrical activities in networks of excitable cells and also tissues simultaneously at multiple sites. Here, an exceptionally fast array system (16 x 16 photodiodes, up to 4,000,000 samples per second, 12-bit resolution) ...

Parosxysmal tachycardia refers to abnormally fast cardiac arrhythmias that suddenly start and stop. Paroxysmal tachycardias can occur in many regions of the heart and may be associated with many different mechanisms. In order to study paroxysmal tachycardias, we have analyzed tissue cultures of cells from embryonic chick heart that are imaged using calcium and voltage ...

Membrane potential in a biological cell depends on the ionic concentration difference between the extracellular and the intracellular medium. Ions close to the membrane show high polarizations under an electric field. Recent theoretical studies have related these polarizations to the alpha (?) dispersions in the impedance spectroscopy of a cell suspension. Therefore these dispersions can be used ...

We present a study of the 3-dimensional (3D) propagation of electrical waves in the heart wall using Laminar Optical Tomography (LOT). Optical imaging contrast is provided by a voltage sensitive dye whose fluorescence reports changes in membrane potential. We examined the transmural propagation dynamics of electrical waves in the right ...

Studies of the spatio-temporal distribution of inhibitory postsynaptic potentials (IPSPs) in a neuron have been limited by the spatial information that can be obtained by electrode recordings. We describe a method that overcomes these limitations by imaging IPSPs with voltage-sensitive dyes. CA1 hippocampal pyramidal neurons from brain slices were loaded with the ...

AbstractStudies of the spatio-temporal distribution of inhibitory postsynaptic potentials (IPSPs) in a neuron have been limited by the spatial information that can be obtained by electrode recordings. We describe a method that overcomes these limitations by imaging IPSPs with voltage-sensitive dyes. CA1 hippocampal pyramidal neurons from brain slices were loaded with the ...

Photoelectric dyes absorb light and convert photon energy to electric potentials. To test whether these dyes could be used for retinal prostheses, a simple in vitro screening system was developed. Retinal neurons were cultured from the eyes of chick embryos at the 10-day embryonic stage, at which time no retinal photoreceptor cells ...

1. The bursting pacemaker neurone R-15 of Aplysia was injected with the Ca2+ sensitive dye arsenzo III. Changes in absorbance were measured with a differential spectrophotometer to monitor changes in free intracellular Ca2+ during membrane depolarization under voltage clamp conditions. 2. Dye absorbance increased ...

A transmitted light without analyzer was led into the pump-probe twist nematic experiment in azo-dye-doped liquid crystals to observe the light scattering from the dye-adsorbed surface during photoalignment. The morphology of the dye-absorbed surface monitored by this transmitted light is correlated with the formation of the ripple ...

F�rster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation to sensitizing dye molecules by F�rster resonant energy transfer. We use ...

We have reported previously that, in otherwise physiological conditions, spreading depression (SD) can be visualized directly by using a fluorescent, voltage-sensitive (VS) dye. However, in stroke models, where depolarizations occur spontaneously near the ischemic core, marked hemodynamic changes interfere significantly with VS dye ...

A skin depth map was built reconstructing photoacoustic signals at several wavelengths of visible and infrared light. The mapping technique was used to follow the diffusion through the skin of near-infrared absorbing dyes. Such dyes can be useful for photodynamic therapy (PDT) of skin lesions and are investigated as contrast agents for ...

We have prepared uniform silica nanoparticles (NPs) doped with a two-photon absorbing zwitterionic hemicyanine dye by reverse microemulsion method. Obvious solvatochromism on the absorption spectra of dye-doped NPs indicates that solvents can partly penetrate into the silica matrix and then affect the ground and excited state of ...

This paper presents a fully integrated PVDF-on-silicon pyroelectric sensor array. The pyroelectric sensor has two main features: a subpixel low noise charge amplifier and a self-absorbing layered structure. The integrated low noise charge amplifier is implemented in a standard CMOS process technology. It is located directly under the sensing structure, maximizing the pixel ...

Long-wavelength absorbing labels that change their color and fluorescence upon conjugation to proteins and other biomolecules provide two critical advantages over the wealth of conventional amine-reactive labels. At first, the progress of the labeling reaction can be monitored continuously either visually or by spectrometry without prior purification. Then, the labeled ...

In the Dye Sensitized Solar Cell (DSSC) the dye sensitizer carries out the light harvesting function and is therefore crucial in determining overall cell efficiency. In addition, the dye sensitizer can influence many of the key electron transfer processes occurring at the TiO(2)/dye/electrolyte interface which also ...

Cosensitization of broadly absorbing ruthenium metal complex dyes with highly absorptive near-infrared (NIR) organic dyes is a clear pathway to increase near-infrared light harvesting in liquid-based dye-sensitized solar cells (DSCs). In cosensitized DSCs, dyes are intimately mixed, and ...

Various lasing conditions, including stable passive mode locking, multispiking operation, and free lasing alternating with multispiking, are examined in the light of a study of more than 90 passive shutters, such as solutions of polymethine dyes, polymethine dyes in a solid matrix, and alkali-halide crystals with Z-centers. The polymethine ...

Photoresist techniques and compositions are provided employing curcumin as an absorptive dye for the purpose of reducing linewidth non-uniformity caused by scattered and reflective light from the substrate-resist interface. The photoresist compositions containing curcumin as the absorptive dye are used in the production of microelectronic circuitry by both ...

Photoresist techniques and compositions are provided employing curcumin as an absorptive dye for the purpose of reducing linewidth non-uniformity caused by scattered and reflective light from the substrate-resist interface. The photoresist compositions containing curcumin as the absorptive dye are used in the production of microelectronic circuitry by both ...

Cyanine dyes are used as the donor fluorophore in energy transfer labels in which light energy is absorbed by a donor fluorophore and transferred to an acceptor fluorophore which responds to the transfer by emitting fluorescent light for detection. The cyanine dyes impart an unusually high sensitivity to the labels thereby improving ...

New push-pull dyes featuring ?-extended tetrathiafulvalene (exTTF) as the donor group and tricyanofuran (TCF) as the acceptor group were synthesized and characterized. Their broad absorption covers the entire visible spectral range and enters the near-infrared region. Electrochemistry and theoretical calculations provided an understanding of these singular electronic ...

Dye-sensitized solar cells have slightly lower photoelectric efficiency than silicon solar cells. Researchers have investigated various ways to address this problem. This study improved the efficiency of a dye-sensitized solar cell by re-driving it with a reflector, reusing discarded light after it was absorbed. The reflector increased ...

The photostability of dye molecules trapped in transparent solid matrices synthesized by the solgel technique was studied both experimentally and theoretically using a model with numerical and approximate analytical solutions. The model is based on a one-photon photodestruction process with the creation of an absorbing bleached molecule. We give the number ...

Recently, intrinsic signal optical imaging has been widely used as a routine procedure for visualizing cortical functional maps. We do not, however, have a well-established imaging method for visualizing cortical functional connectivity indicating spatio-temporal patterns of activity propagation in the cerebral cortex. In the present study, we developed a novel experimental setup for investigating ...

The spatial and temporal patterns of neocortex activation are determined not only by the dynamic character of the input but also by the intrinsic dynamics of the cortical circuitry. To study the role of afferent input frequency on cortical activation dynamics, the electrical activity of in vitro neocortex slices was imaged during white-matter electrical stimulation. High-speed optical imaging was ...

Corticotropin-releasing hormone (CRH) is thought to play an important role in the pathophysiology of stress-related psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). However, knowledge about the actions of CRH at the neuronal network level is only scarce. Here, we examined whether CRH affects neuronal activity propagation through the ...

Independent component analysis (ICA) is a technique that can be used to extract the source signals from sets of signal mixtures where the sources themselves are unknown. The analysis of optical recordings of invertebrate neuronal networks with fast voltage-sensitive dyes could benefit greatly from ICA. These experiments can generate hundreds of voltage ...

Independent component analysis (ICA) is a technique that can be used to extract the source signals from sets of signal mixtures where the sources themselves are unknown. The analysis of optical recordings of invertebrate neuronal networks with fast voltage-sensitive dyes could benefit greatly from ICA. These experiments can generate hundreds of voltage ...

Spontaneous slow-wave oscillations of neuronal membrane potential occur about once every second in the rodent cortex and may serve to shape the efficacy of evoked neuronal responses and consolidate memory during sleep. However, whether these oscillations reflect the entrainment of all cortical regions via propagating waves or whether they exhibit regional and temporal heterogeneity that reflects ...

In many brain areas, circuit connectivity is segregated into specific lamina or glomerula. Functional imaging in these anatomically discrete areas is particularly useful in characterizing circuit properties. Voltage-sensitive dye (VSD) imaging directly assays the spatiotemporal dynamics of neuronal activity, including the functional connectivity of the ...

Intact single twitch fibres from frog muscle were isolated and mounted in a normal Ringer solution (16 degrees C) on an optical bench apparatus for measuring fibre absorbance as a function of the wave-length and polarization of the incident light. Fibre absorbance was measured in resting fibres both in the absence and in the presence of one of three ...

This review presents three examples of using voltage- or calcium-sensitive dyes to image the activity of the brain. Our aim is to discuss the advantages and disadvantages of each method with particular reference to its application to the study of the brainstem. Two of the examples use wide-field (one-photon) imaging; the third uses two-photon scanning microscopy. Because the ...

Previous studies have speculated, based on indirect evidence, that the action potential at the transverse (t)-tubules is longer than at the surface membrane in mammalian ventricular cardiomyocytes. To date, no technique has enabled recording of electrical activity selectively at the t-tubules to directly examine this hypothesis. We used confocal line-scan imaging in conjunction with the fast ...

The simultaneous recording of many individual neurons is fundamental to understanding the integral functionality of neural systems. Imaging with voltage-sensitive dyes (VSDs) is a key approach to achieve this goal and a promising technique to supplement electrophysiological recordings. However, the lack of connectivity maps between imaged neurons and the requirement of ...

The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of ?100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal ...

The development of modern neuroscience tools is critical for deciphering brain circuit organization and function. An important aspect for technical development is to enhance each technique's advantages and compensate for limitations. We developed a high-precision and fast functional mapping technique in brain slices that incorporates the spatial precision of activation that can be achieved by ...

Measuring signal transduction in large numbers of cells, with high spatial and temporal resolution, is a fundamental problem for studying information processing in the nervous system. To address this problem, a family of detectors that are chimeras between signal transduction proteins and fluorescent proteins has been designed. The prototype sensor is a genetically encoded probe that can be used ...

A multiple independent component analysis (ICA) method based on the noisy time-delayed decorrelation algorithm is described that overcomes the problems and improves the usefulness of conventional ICA, which is commonly used for extracting the actual neural activity from data measured using optical recording with a voltage-sensitive dye to visualize neural activities in ...

We review the use of optical coherence tomography (OCT) for detection of neural activity, and present a new approach for depth-localization of neural action potentials (APs) using voltage-sensitive dyes as contrast agents in OCT. A stained squid giant axon is imaged by spectral-domain OCT. Changes in the intensity and phase of back-scattered light coming ...

We review the use of optical coherence tomography (OCT) for detection of neural activity, and present a new approach for depth-localization of neural action potentials (APs) using voltage-sensitive dyes as contrast agents in OCT. A stained squid giant axon is imaged by spectral-domain OCT. Changes in the intensity and phase of back-scattered light coming ...

A new and original experiment in which partition of bromophenol blue dye between water and lipid/water gel causes a shift in the acid base equilibrium of the dye is described. The dye-absorbing material is a monoglyceride food additive of plant origin that mixes freely with water to form a stable cubic phase gel; the nascent gel ...

Optical imaging of neuronal activity offers new possibilities for understanding brain physiology. The predominant methods in neuroscience for measuring electrical activity require electrodes inserted into the tissue. Such methods, however, provide limited spatial information and are invasive. Optical methods are less physically invasive and offer the possibility for simultaneously imaging the ...

A comprehensive photophysical study of the linear and nonlinear absorption properties has been carried out on two series of two-photon absorbing dyes to gain insight into how structure-property relationships influence observed nonlinear absorption. The ma...

Four aluminosilicate sorbents (montmorillonite, bentonite, raw perlite, and expanded perlite) were employed for retention of the cationic dye C.I. Basic Blue 41. Interactions between the clay and the dyestuff were investigated at several temperatures and clay:dye ratios. The mechanism behind the adsorption involves the formation of H-aggregates of the ...

Experiments are described illustrating enhanced photon trapping and efficient energy transfer in mixed-dye planar solar concentrators containing, for example, Rhodamine 6G and Coumarin 6. These concentrators intercept more of the solar spectrum to give an enhanced photon-flux gain that exceeds the single-dye concentrator. It is also shown that the energy ...

Experiments are described illustrating enhanced photon trapping and efficient energy transfer in mixed-dye planar solar concentrators containing, for example, Rhodamine 6G and Coumarin 6. These concentrators intercept more of the solar spectrum to give an enhanced photon-flux gain that exceeds the single-dye concentrator. It is also shown that the energy ...

A small colorimetric dosimeter of the glass-dye type is described for use in the range 10/sup 7/ to 10/sup 9/ ergs/g. The dosimeter comprises a porous, cellular silica matrix containing a radiation-sensitive dye within its pores. The matrix has a density of approximates 1.45 and a developed surface area approximates 200 m/sup 2//g, and the ...

The wastewaters released by textile industries to the environment contain hazardous compounds like toxic refractory dye stuff at high concentration. In this study, electron beam irradiation-induced decoloration and decomposition of C.I. Direct Black 22 aqueous solutions were investigated. The influences of absorbed doses and initial ...

29-fsec optical pulses at a center wavelength of 615 nm have been generated from a linear-cavity synchronously pumped dye laser without using the colliding-pulse mode-locking technique. The laser consists of two dye jets (a gain jet and a saturable absorber jet) and a sequence of four Brewster-angled prisms. Kiton Red S is used as the ...

A light weight, low cost, non-corroding, high efficiency solar energy collector is comprised of an absorber plate which is adapted to absorb solar energy in the form of heat and to transfer by conductance the heat to a heat exchange medium. The absorber plate has disposed therein a highly heat conductive filler which imparts increased ...

This study describes investigations conducted to develop optimization criteria for passive mode locking in YAG lasers. More than 90 passive shutters based on saturating absorbers with polymethine dyes in the liquid and solid phases, as well as alkali halide crystals with Z centers, are investigated. The findings make it possible to assess the limiting ...

The laser dye Kiton Red S dissolved in ethanol was degraded under flashlamp excitation in a dye laser. Data obtained with infrared spectral analysis were used to construct plots of dye concentration versus shot number. From these plots the degradation reaction was found to be zeroth order in Kiton Red S. A rate equation was determined. ...

A photocatalytic process based on immobilized titanium dioxide was used to treat crude solutions of azo, anthraquinone and phthalocyanine textile dyes. In addition, the process was applied to the treat autoxidized chemically reduced azo dyes, i.e. representatives of recalcitrant dye residues after biological sequential ...

A novel method was developed for characterizing changes in coal and mineral surfaces resulting from sonication and other cleaning processes. This method employs a unique flow-cell to permit the dynamic measurement of dye adsorption on coal and mineral particle surfaces. The rates and extents of adsorption of ionic dyes on Illinois No. 6 coal were found to ...

We have prepared uniform silica nanoparticles (NPs) doped with a two-photon absorbing zwitterionic hemicyanine dye by reverse microemulsion method. Obvious solvatochromism on the absorption spectra of dye-doped NPs indicates that solvents can partly penetrate into the silica matrix and then affect the ground and excited state of ...

Several dyes in water were individually exposed to corona discharge. Light absorbance decreased for all organic dyes with time. Absorbance losses with methylene blue, malachite green, and new coccine were studied. The loss of color was followed using an in situ colorimeter and the effects of varying the current, ...

The photosynthetic growth action spectrum of a green alga at three bands of visible light (blue, orange, and red) at fixed quanta input and under light-limiting conditions was measured in a batch cultivation system. Quantum efficiencies (biomass dry weight increment per quanta absorbed) were better in the yellow-red region than in the blue region. Results served as a basis for ...

Photoelectric dyes, which absorb light and convert photon energy to electric potentials, have been previously shown to stimulate retinal neurons in culture. In this study, a photoelectric dye was coupled to a polyethylene film surface and tested in vitro using retinal tissues from chick embryos at the 12-day embryonic stage, at which ...

Electron transfer from the excited state of sensitizing dyes to the conduction band of semiconductors has been studied through photoelectrochemical techniques. Two systems were analyzed in detail: rhodamine B on ZnO and rose bengal on TiO/sub 2/. Prior to electrochemical experimentation, the adsorption characteristics of these dyes were investigated using ...