- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Gaussian FRET two-hybrid assays for determining the stoichiometry of hetero-oligomeric complexes in single living cells
摘要： Here we integrate multiple Gaussian-functions analysis into fluorescence resonance energy transfer (FRET) two-hybrid assays (Gaussian FRET two-hybrid assay) to determine the stoichiometric ratios of intracellular hetero-oligomers in single living cells. This method adopts in multiple Gaussian-functions to fit the E-count histograms of both donor- and acceptor-centric FRET efficiency (ED and EA) images of a single cell for obtaining the peak values (EDi and EAi), thus yielding the corresponding stoichiometric ratios (EDi/EAi) of intracellular hetero-oligomers. We performed Gaussian FRET two-hybrid assay for living Hela cells coexpressing different FRET tandem plasmids, and obtained consistent results with the expected values. Gaussian FRET two-hybrid assay for cells coexpressing Bad-CFP and Bcl-XL-YFP reveals that Bcl-XL binds with Bad to form a hetero-oligomeric complex with a stoichiometry of 2:1 on mitochondria.
关键词： Multiple Gaussian-functions analysis,FRET imaging,Single living cell,Stoichiometry,Hetero-oligomeric complex
更新于2025-11-21 11:24:58
-
Photo-physical properties of substituted 2,3-distyryl indoles: Spectroscopic, computational and biological insights
摘要： The structural dependence of the photo-physical properties of substituted 2,3-distyryl (23DSI) indoles were studied using several spectroscopic techniques including steady-state UV-VIS spectroscopy, steady-state fluorescence spectroscopy, steady-state excitation spectroscopy, time correlated single photon counting (TCSPC) spectroscopy, and time-resolved fluorescence upconversion spectroscopy (TRFLS). Each of 23DSI derivatives investigated showed distinct fluorescence emission and UV-VIS spectra, indicating strong structural dependence of the emission and the excitation. The UV-VIS spectra of the 23DSI derivatives showed three main identical absorption bands with minor deviations in the absorbance caused by substituent groups on the distyryl rings. The time-resolved fluorescence up-conversion studies indicated that the fluorescence undergoes a mono-exponential decay whereas the calculated fluorescence lifetime showed relatively short fluorescence lifetimes of approximately 1 ns. All of the 23DSI derivatives showed two-photon absorption upon direct excitation of 1.6 W laser pulses at 800 nm. These studies suggest that the substituents, attached to distyryl core, are capable of boosting or hindering fluorescence intensities by distorting the π-conjugation of the 23DSI molecule. Our studies showed that 23DSI (p-F) has the highest fluorescence emission quantum yield. Theoretical calculations for the ground state of 23DSI derivatives confirmed differences in electron densities in 23DSI derivatives in the presence of different substituent attachments. The excellent fluorescence emission, high fluorescence quantum yield and two-photon absorption properties of these 23DSI molecules make them attractive candidates for potential applications in the fields of biological imaging, biomedicine, fluorescent probes, and photodynamic inactivation (PDI). B. subtilis samples, treated with micro molar solutions of 23DSI (p-OCH3) and 23DSI (p-CH3), showed very effective photodynamic inactivation (PDI) upon irradiation with white light.
关键词： Two photon absorption,Time-resolved fluorescence upconversion laser spectroscopy,Photodynamic inactivation,Gaussian calculations,Photo-physical properties,Light-activation
更新于2025-11-14 15:26:12
-
[IEEE 2018 Second International Conference on Electronics, Communication and Aerospace Technology (ICECA) - Coimbatore (2018.3.29-2018.3.31)] 2018 Second International Conference on Electronics, Communication and Aerospace Technology (ICECA) - Image Reconstruction Through Compressed Sensing Technique Using Gaussian Filteration
摘要： Image Processing is becoming as the one of the most emerging field in the research area, as we know in today's life, lot of people are using these images somewhere in their daily life. In this paper, i have developed the satellite images in which we can have even more clear view than the input taken image by using compressive reconstruction technique. After passing through some stages of the processing, we have used a gaussian filteration so that we can have a very good output image at an end. By taking various references through different sites I got a hope of developing a normal satellite taken image into clearly processed output image through the basis pursuit reconstruction and by doing filteration after it.
关键词： gaussian filter,compressed sensing,gaussian matrix,basis pursuit
更新于2025-09-23 15:23:52
-
Propagation properties of Airy Ince–Gaussian wave packets in gradient-index media
摘要： We study localized Airy Ince–Gaussian (AiIG) wave packets in gradient-index (GRIN) media by solving the spatiotemporal evolution equation analytically. The generation and manipulation of AiIG wave packets in GRIN media are affected by the direction of the self-accelerating, elliptical, refractive index distribution parameter, initial velocity and mode number. In addition, energy flow, angular momentum and radiation force, which change periodically, are also thoroughly discussed. The Airy helical Ince–Gaussian wave packets exhibit multiple vortices and carry orbital angular momentum, which have potential applications in optical tweezers and optical communications.
关键词： vortex,Airy Ince–Gaussian wave packets,propagation
更新于2025-09-23 15:23:52
-
Multi-point Gaussian States, Quadratic–Exponential Cost Functionals, and Large Deviations Estimates for Linear Quantum Stochastic Systems
摘要： This paper is concerned with risk-sensitive performance analysis for linear quantum stochastic systems interacting with external bosonic fields. We consider a cost functional in the form of the exponential moment of the integral of a quadratic polynomial of the system variables over a bounded time interval. Such functionals are related to more conservative behaviour and robustness of systems with respect to statistical uncertainty, which makes the challenging problems of their computation and minimization practically important. To this end, we obtain an integro-differential equation for the time evolution of the quadratic–exponential functional, which is different from the original quantum risk-sensitive performance criterion employed previously for measurement-based quantum control and filtering problems. Using multi-point Gaussian quantum states for the past history of the system variables and their first four moments, we discuss a quartic approximation of the cost functional and its infinite-horizon asymptotic behaviour. The computation of the asymptotic growth rate of this approximation is reduced to solving two algebraic Lyapunov equations. Further approximations of the cost functional, based on higher-order cumulants and their growth rates, are applied to large deviations estimates in the form of upper bounds for tail distributions. We discuss an auxiliary classical Gaussian–Markov diffusion process in a complex Euclidean space which reproduces the quantum system variables at the level of covariances but has different fourth-order cumulants, thus showing that the risk-sensitive criteria are not reducible to quadratic–exponential moments of classical Gaussian processes. The results of the paper are illustrated by a numerical example and may find applications to coherent quantum risk-sensitive control problems, where the plant and controller form a fully quantum closed-loop system, and other settings with nonquadratic cost functionals.
关键词： Linear quantum stochastic system,Gaussian quantum state,Risk-sensitive quantum control
更新于2025-09-23 15:23:52
-
Multi-source Remote Sensing Image Registration Based on Contourlet Transform and Multiple Feature Fusion
摘要： Image registration is an indispensable component in multi-source remote sensing image processing. In this paper, we put forward a remote sensing image registration method by including an improved multi-scale and multi-direction Harris algorithm and a novel compound feature. Multi-scale circle Gaussian combined invariant moments and multi-direction gray level co-occurrence matrix are extracted as features for image matching. The proposed algorithm is evaluated on numerous multi-source remote sensor images with noise and illumination changes. Extensive experimental studies prove that our proposed method is capable of receiving stable and even distribution of key points as well as obtaining robust and accurate correspondence matches. It is a promising scheme in multi-source remote sensing image registration.
关键词： contourlet transform,multi-source remote sensing image registration,multi-direction gray level co-occurrence matrix,multi-scale circle Gaussian combined invariant moment,Feature fusion
更新于2025-09-23 15:23:52
-
A novel natural image noise level estimation based on flat patches and local statistics
摘要： This paper proposes a high-precision algorithm for noise level estimation. Different from existing algorithms, we present a new noise level estimation algorithm by linearly combining the overestimated and underestimated results using combinatorial coefficients that can be tailored to the problem at hand. The algorithm has two distinct features: it avoids the underestimation of noise level estimation algorithms that employ the minimum eigenvalue and demonstrates higher accuracy and robustness for a large range of visual content and noise conditions. The experimental results that are obtained in this study demonstrate that the proposed algorithm is effective for various scenes with various noise levels. The software release of the proposed algorithm is available online at https://ww2.mathworks.cn/matlabcentral/fileexchange/64519-natural-image-noise-level-estimation-based-on-flat-patches-and-local-statistics.
关键词： Covariance matrix,Eigenvalue,Flat patches,Gaussian noise,Noise level estimation
更新于2025-09-23 15:23:52
-
Exploring the optical beam shifts in monolayers of transition metal dichalcogenides using Gaussian beams
摘要： We have extensively studied Goos-H?nchen (GH) and Imbert-Fedorov (IF) shifts for reflection of a fundamental Gaussian beam using transfer matrix method. By considering a dielectric slab coated with monolayer of transition metal dichalcogenides (TMDC), we theoretically investigate the potential role of four different TMDC monolayers (WS2, WSe2, MoS2, and MoSe2) on the spatial and angular GH and IF shifts for reflection of the light beam that has not been explored previously. We find the nature of GH and IF shifts to be explicitly dependent on the mode of polarization of light beam. In case of partial reflection of light, both GH and IF shifts acquire moderate magnitude. In contrary, giant negative spatial GH shifts are examined for total internal reflection. Our analysis revealed that the typical characteristics of GH and IF shifts are significantly affected by the complex surface conductivity of TMDC monolayers and consequently the shifts are found to differ for different TMDC monolayers. We also present a comparison of the beam shifts for the monolayer TMDC-coated surfaces with the corresponding bulk TMDCs. Finally, we address the most significant question of how the GH and IF shifts depend upon the wavelengths of incident light, in particular, establishing the role of optical conductivity in beam shifts.
关键词： Light matter interaction,Goos-H?nchen shift,Surface Optics,Gaussian beam,Transition metal dichalcogenides,Imbert-Fedorov shift
更新于2025-09-23 15:23:52
-
An image thresholding approach based on Gaussian mixture model
摘要： Image thresholding is an important technique for partitioning the image into foreground and background in image processing and analysis. It is difficult for traditional thresholding methods to get satisfactory performance on the noisy and uneven grayscale images. In this paper, we propose an image thresholding approach based on Gaussian mixture model (GMM) to solve this problem. GMM assumes that image is a mixture of two unknown parameters’ Gaussian distributions, which corresponds to foreground and background, respectively. Based on this assumption, we adopt expectation maximization algorithm with a simple initialization strategy to estimate the statistical parameters and utilize Bayesian criteria to generate the binary map. Furthermore, we calculate the posterior probabilities in consideration of neighborhood effect to achieve good performance on noisy and uneven grayscale images. Experimental results conducted on the synthetic and real images demonstrate the effectiveness of the proposed method.
关键词： Image thresholding,Gaussian mixture model,EM algorithm,Neighborhood information
更新于2025-09-23 15:23:52
-
Multi-configurational Ehrenfest simulations of ultrafast nonadiabatic dynamics in a charge-transfer complex
摘要： Multi-configurational Ehrenfest (MCE) approaches, which are intended to remedy the lack of correlations in the standard mean-field Ehrenfest method, have been proposed as coherent-state based ans?tze for quantum propagation [D. V. Shalashilin, J. Chem. Phys. 130, 244101 (2009)] and also as the classical limit of the variational Gaussian-based multiconfiguration time dependent Hartree (G-MCTDH) method [S. R?mer and I. Burghardt, Mol. Phys. 111, 3618 (2013)]. In the present paper, we establish the formal connection between these schemes and assess the performance of MCE for a coherent-state representation of the classical-limit subsystem. As a representative model system, we address the ultrafast, coherent charge transfer dynamics in an oligothiophene-fullerene donor-acceptor complex described by a two-state linear vibronic coupling model. MCE calculations are compared with reference calculations performed with the MCTDH method, for 10–40 vibrational modes. Beyond a dimensionality of 10 modes, it is shown that the correct representation of electronic coherence depends crucially on the sampling of initially unoccupied Gaussians.
关键词： nonadiabatic dynamics,Multi-configurational Ehrenfest,Gaussian wavepackets,MCTDH,ultrafast dynamics,charge-transfer complex
更新于2025-09-23 15:23:52