The Experts below are selected from a list of 9735 Experts worldwide ranked by ideXlab platform
G. Krishnamoorthy - One of the best experts on this subject based on the ideXlab platform.
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depth dependent heterogeneity in membranes by fluorescence Lifetime Distribution analysis
Journal of Physical Chemistry Letters, 2012Co-Authors: Sourav Haldar, G. Krishnamoorthy, Mamata Kombrabail, Amitabha ChattopadhyayAbstract:Biological membranes display considerable anisotropy due to differences in composition, physical characteristics, and packing of membrane components. In this Letter, we have demonstrated the environmental heterogeneity along the bilayer normal in a depth-dependent manner using a number of anthroyloxy fatty acid probes. We employed fluorescence Lifetime Distribution analysis utilizing the maximum entropy method (MEM) to assess heterogeneity. Our results show that the fluorescence Lifetime heterogeneity varies considerably depending on fluorophore location along the membrane normal (depth), and it is the result of the anisotropic environmental heterogeneity along the bilayer normal. Environmental heterogeneity is reduced as the reporter group is moved from the membrane interface to a deeper hydrocarbon region. To the best of our knowledge, our results constitute the first experimental demonstration of anisotropic heterogeneity in bilayers. We conclude that such graded environmental heterogeneity represents ...
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Fluorescence Lifetime Distribution in Characterizing Membrane Microheterogeneity
Journal of Fluorescence, 2001Co-Authors: G. KrishnamoorthyAbstract:Realistic description of biomembrane heterogeneity is essential for understanding the complexity of their function. Application of the Distribution of the fluorescence Lifetime of membrane probes, especially by the maximum entropy method, in studying membrane heterogeneity is described. Representative studies on various membranes and the information brought out in these studies are reviewed. An example is provided wherein the water-wire hypothesis of transmembrane proton transport gets experimental support from Nile Red fluorescence Lifetime Distribution analysis. Future directions in the use of this methodology in cell physiology are indicated.
Min Gu - One of the best experts on this subject based on the ideXlab platform.
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Lifetime Distribution of spontaneous emission from emitter s in three dimensional woodpile photonic crystals
Optics Express, 2011Co-Authors: Haoxiang Jiang, Xue-hua Wang, Min GuAbstract:Spontaneous emission Lifetime Distribution in the basic unit cell or on a plane of the excited emitters embedded in woodpile photonics crystals with low refractive index contrast are investigated. It is found that the spontaneous emission Lifetime Distribution strongly depends on the position and transition frequency of the emitters, and has the same symmetry as that of the unit cell. The Lifetimes of emitters near the upper gap edge are longer than that in the center of the pseudo-gap, which is quite a contrast to the conventional concept. Furthermore, it is revealed that the polarization orientation of the emitters has significant influence on the Lifetime Distribution, and may result in a high anisotropy factor (defined as the difference between the maximum and minimum values of the Lifetime) up to 4.2. These results may be supplied in probing the Lifetime Distribution or orientation-dependent local density of states in future experiments.
Karsten Gall - One of the best experts on this subject based on the ideXlab platform.
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fluorescence intensity and Lifetime Distribution analysis toward higher accuracy in fluorescence fluctuation spectroscopy
Biophysical Journal, 2002Co-Authors: Kaupo Palo, Leif Brand, Christian Eggeling, Stefan Jager, Peet Kask, Karsten GallAbstract:Fluorescence fluctuation methods such as fluorescence correlation spectroscopy and fluorescence intensity Distribution analysis (FIDA) have proven to be versatile tools for studying molecular interactions with single molecule sensitivity. Another well-known fluorescence technique is the measurement of the fluorescence Lifetime. Here, we introduce a method that combines the benefits of both FIDA and fluorescence Lifetime analysis. It is based on fitting the two-dimensional histogram of the number of photons detected in counting time intervals of given width and the sum of excitation to detection delay times of these photons. Referred to as fluorescence intensity and Lifetime Distribution analysis (FILDA), the technique distinguishes fluorescence species on the basis of both their specific molecular brightness and the Lifetime of the excited state and is also able to determine absolute fluorophore concentrations. The combined information yielded by FILDA results in significantly increased accuracy compared to that of FIDA or fluorescence Lifetime analysis alone. In this paper, the theory of FILDA is elaborated and applied to both simulated and experimental data. The outstanding power of this technique in resolving different species is shown by quantifying the binding of calmodulin to a peptide ligand, thus indicating the potential for application of FILDA to similar problems in the life sciences.
Xue-hua Wang - One of the best experts on this subject based on the ideXlab platform.
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Lifetime Distribution of spontaneous emission from quantum dots in three-dimensional woodpile photonic crystals
2012Co-Authors: Xue-hua Wang, H. X. JiangAbstract:Spontaneous emission Lifetime Distribution in the basic unit cell or on a plane of the excited quantum dots embedded in woodpile photonics crystals with low refractive index contrast are investigated. It is found that the spontaneous emission Lifetime Distribution strongly depends on the position and transition frequency of the emitters, and has the same symmetry as that of the unit cell. Furthermore, it is revealed that the polarization orientation of the emitters has significant influence on the Lifetime Distribution. These results may be supplied in probing the Lifetime Distribution or orientation-dependent local density of states in future experiments.
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Lifetime Distribution of spontaneous emission from emitter s in three dimensional woodpile photonic crystals
Optics Express, 2011Co-Authors: Haoxiang Jiang, Xue-hua Wang, Min GuAbstract:Spontaneous emission Lifetime Distribution in the basic unit cell or on a plane of the excited emitters embedded in woodpile photonics crystals with low refractive index contrast are investigated. It is found that the spontaneous emission Lifetime Distribution strongly depends on the position and transition frequency of the emitters, and has the same symmetry as that of the unit cell. The Lifetimes of emitters near the upper gap edge are longer than that in the center of the pseudo-gap, which is quite a contrast to the conventional concept. Furthermore, it is revealed that the polarization orientation of the emitters has significant influence on the Lifetime Distribution, and may result in a high anisotropy factor (defined as the difference between the maximum and minimum values of the Lifetime) up to 4.2. These results may be supplied in probing the Lifetime Distribution or orientation-dependent local density of states in future experiments.
Haoxiang Jiang - One of the best experts on this subject based on the ideXlab platform.
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Lifetime Distribution of spontaneous emission from emitter s in three dimensional woodpile photonic crystals
Optics Express, 2011Co-Authors: Haoxiang Jiang, Xue-hua Wang, Min GuAbstract:Spontaneous emission Lifetime Distribution in the basic unit cell or on a plane of the excited emitters embedded in woodpile photonics crystals with low refractive index contrast are investigated. It is found that the spontaneous emission Lifetime Distribution strongly depends on the position and transition frequency of the emitters, and has the same symmetry as that of the unit cell. The Lifetimes of emitters near the upper gap edge are longer than that in the center of the pseudo-gap, which is quite a contrast to the conventional concept. Furthermore, it is revealed that the polarization orientation of the emitters has significant influence on the Lifetime Distribution, and may result in a high anisotropy factor (defined as the difference between the maximum and minimum values of the Lifetime) up to 4.2. These results may be supplied in probing the Lifetime Distribution or orientation-dependent local density of states in future experiments.
