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- 摘要
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- 实验方案
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Monomeric cohesin state revealed by live‐cell single‐molecule spectroscopy
摘要： The cohesin complex plays an important role in the maintenance of genome stability. Cohesin is composed of four core subunits and a set of regulatory subunits that interact with the core subunits. Less is known about cohesin dynamics in live cells and on the contribution of individual subunits to the overall complex. Understanding the tethering mechanism of cohesin is still a challenge, especially because the proposed mechanisms are still not conclusive. Models proposed to describe tethering depend on either the monomeric cohesin ring or a cohesin dimer. Here, we investigate the role of cohesin dynamics and stoichiometry in live yeast cells at single-molecule resolution. We explore the effect of regulatory subunit deletion on cohesin mobility and found that depletion of different regulatory subunits has opposing effects. Finally, we show that cohesin exists mostly as a canonical monomer throughout the cell cycle, and its monomeric form is independent of its regulatory factors. Our results demonstrate that single-molecule tools have the potential to provide new insights into the cohesin mechanism of action in live cells.
关键词： cohesin,photon counting histogram,chromosome,fluorescence correlation spectroscopy,SMC complexes
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - An Optimization Scheme based on Transmitters Selection for MIMO VLC Systems
摘要： Multi-input and multi-output (MIMO) visible light communication (VLC) is one of the promising solutions for future network environment. Considering in most cases, the transmitters and the receivers cannot meet the requirements of the ideal layout. This paper presents an in-depth study on the channel matrix of the MIMO visible light communication system. The singular value decomposition (SVD) is used to select the transmitters which have good performance for transmission, and the corresponding power is allocated according to the principle of equal bit error rate (BER) of the receivers. Simulation results show that this method can effectively improve the channel capacity of MIMO VLC system, and can achieve good BER performance for each receiver.
关键词： BER,MIMO system,visible light communication,channel correlation
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Photon correlation method for acoustic pressure measurement in free sound field
摘要： Microphones are calibrated by reciprocity method currently，but not for the nonstandard size microphones. To solve the calibration problem for nonstandard microphones, research on a non-invasive optical method for acoustic pressure measurement in free sound field. By auto-correlating scattered photon sequences, the particle velocity can be measured, and further acquiring the acoustic pressure at certain position. Experiment results show , the difference between photon correlation method and standard microphone is within 0.61 dB when the acoustic frenquency is between 200Hz and 8kHz, verifying the feasibility of the correlation method.
关键词： particle velocity,free sound field,Photon auto-correlation,acoustic pressure
更新于2025-09-16 10:30:52
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Improved sensitivity of laser-enhanced 1Hα-13Cα-correlation via suppression of Cα-C′ scalar-coupling evolution
摘要： Low-concentration photochemically induced dynamic polarization (LC-photo-CIDNP) enables the spectroscopic analysis of biomolecules containing the amino acids Trp and Tyr at sub-micromolar concentration in solution. Typical LC-photo-CIDNP pulse sequences involving 1H-13C correlation, however, perform well in the case of aromatic resonances but display a relatively poor signal-to-noise ratio for 13Ca and 13Cb resonances. Here, we develop a novel pulse sequence denoted as 13C perturbation-recovered selective-pulse photo-CINDP enhanced reverse INEPT, or 13C PRESPRINT, tailored to the LC-photo-CIDNP analysis of 1H-13Ca pairs. Our method, which is based on full suppression of 1-bond Ca-C0 scalar-coupling evolution during the constant-time delay, results into a sensitivity improvement by a factor of 2. The enhanced performance of this pulse sequence enabled us to improve the analysis of LC-photo-CIDNP laser-power dependence at very low (200 nM) sample concentration. An improved theoretical model, developed to quantitatively describe this laser-power dependence, shows excellent agreement with our 13C PRESPRINT experimental data.
关键词： LC-photo-CIDNP,Photo-CIDNP,Hyperpolarization,1H-13Ca correlation,NMR sensitivity
更新于2025-09-16 10:30:52
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Automatic seam detection and tracking system for robots based on laser vision
摘要： Detecting weld seams and accurately locating them from time-series images that contain strong noise pollution are di?cult and lead to reduced tracking accuracy. To address this problem, this paper presents a seam detection and tracking algorithm from the perspective of seam feature extraction and seam detection and positioning. The proposed image-processing algorithm employs the powerful feature expression capability and self-learning function of the deep convolutional neural network. A real-time weld seam searching and positioning strategy based on the multi-correlation ?lter cooperative detection mechanism is proposed in consideration of the continuity of the motion of the feature points of adjacent frames and the correlation of laser stripe structural information. Experimental results show that the sensor’s measurement frequency can reach 20 Hz, the average absolute tracking error of straight or curved welds is less than 0.25 mm, and the maximum tracking error does not exceed 1 mm in an environment with strong arc and splash noise. Moreover, the welding torch end runs smoothly during welding. The proposed strategy can meet high-quality welding requirements.
关键词： Correlation ?lter,Deep convolutional neural network,Laser vision sensor,Seam tracking
更新于2025-09-16 10:30:52
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Su2058 – Interpretation of Volumetric Laser Endomicroscopy in Barrett’s Esophagus Using Image Enhancement Software
摘要： Volumetric laser endomicroscopy (VLE) is a second-generation optical coherence tomography platform that provides comprehensive imaging of Barrett's esophagus (BE). In-depth interpretation of a full VLE scan is complicated by subtle feature variations across a large amount of data (1200 frames). Intelligent real-time image segmentation (IRIS) is an artificial intelligence based image processing software that highlights established VLE features using a color-graded scale superimposed over cross-sectional and reconstructed en-face views. IRIS features include (1) surface hyper-reflectivity (signal attenuation), a pink graded color scale at the epithelial surface, (2) hypo-reflective structures (epithelial glands), filled by a solid blue color, and (3) lack of layered architecture, represented by an orange graded color bar at the external rim of the VLE image. This study aims to provide a description of IRIS features of various gastroesophageal tissue types using histologic correlation.
关键词： Volumetric laser endomicroscopy,Barrett's esophagus,IRIS,histologic correlation
更新于2025-09-16 10:30:52
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Luminescent properties of Dy3+/Eu3+ doped fluorescent glass for white LED based on oxyfluoride matrix
摘要： Rare earth ion-doped fluorescent glass has become a hotspot due to its characteristics. This work shows that the prepared Dy3+ and Dy3+/Eu3+ doped glasses have white light emission under ultraviolet excitation. There is a higher yellow light/blue light (Y/B) value, indicating an increase in the covalentity of Dy-O, and decrease in the symmetry with the increasing concentration of dopants (Dy3+). The correlated color temperature (CCT) can be effectively reduced by the red light emission of Eu3+, and the order of influence of excitation wavelength on CCT is 395 nm > 382 nm > 365 nm .The delay curve demonstrates that the energy transfer from Dy3+ to Eu3+. The glass has the characteristics of anti-blue light damage and wide tunable color temperature, which illustrates that it has potential application in the field of white LED.
关键词： correlation color temperature,rare earths,oxyfluoride glass,Y/B intensity ratio,energy transfer
更新于2025-09-16 10:30:52
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Performance of Distributed Optical Fiber Sensors (DOFS) and Digital Image Correlation (DIC) in the monitoring of RC structures
摘要： Distributed Optical Fiber Sensors (DOFS) are strain measuring tools whose potential related to the civil engineering field has been discovered in the latest years only. A unique utility lies in the possibility of bonding these extremely thin sensors to steel reinforcement bars which will later be embedded in concrete elements (RC) in order to monitor its mechanical strains. The present paper presents the results of an experimental campaign that saw the tensing of two RC tensile members (ties) with DOFS-instrumented steel rebars providing strain readings every 7.5mm. Their cracking behavior allows to gain insight on the steel rebar’s strain profile when surrounded by cracking concrete. The described results are novel as measurements that are accurate, completely distributed, experimentally extracted, both before and after concrete cracking, have been impossible up until now. The internal strain measurements are additionally integrated with an external Digital Image Correlation (DIC) monitoring which provides data on the displacements and strains of the members’ surfaces. The present research represents the beginning of an in-depth experimental campaign aimed at providing reinforcement strain data for multiple loaded RC ties encompassing different geometrical features (concrete cover, reinforcement ratio, bar diameter).
关键词： strain monitoring,concrete cracking,Digital Image Correlation (DIC),Distributed Optical Fiber Sensors (DOFS),RC structures
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - A Modular Source of Entangled Photon Pairs in Femtosecond-Laser Written Waveguide Circuits
摘要： Robust classi?cation becomes challenging when each class consists of multiple subclasses. Examples include multi-font optical character recognition and automated protein function prediction. In correlation-based nearest-neighbor classi?cation, the maximin correlation approach (MCA) provides the worst-case optimal solution by minimizing the maximum misclassi?cation risk through an iterative procedure. Despite the optimality, the original MCA has drawbacks that have limited its wide applicability in practice. That is, the MCA tends to be sensitive to outliers, cannot effectively handle nonlinearities in datasets, and suffers from having high computational complexity. To address these limitations, we propose an improved solution, named regularized MCA (R-MCA). We ?rst reformulate MCA as a quadratically constrained linear programming (QCLP) problem, incorporate regularization by introducing slack variables in the primal problem of the QCLP, and derive the corresponding Lagrangian dual. The dual formulation enables us to apply the kernel trick to R-MCA, so that it can better handle nonlinearities. Our experimental results demonstrate that the regularization and kernelization make the proposed R-MCA more robust and accurate for various classi?cation tasks than the original MCA. Furthermore, when the data size or dimensionality grows, R-MCA runs substantially faster by solving either the primal or dual (whichever has a smaller variable dimension) of the QCLP. The source code of the proposed R-MCA methodology is available at http://data.snu.ac.kr/rmca.
关键词： Nearest neighbor,kernel trick,regularization,correlation,SOCP,QCLP,maximin,QP
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - CdMgTe as an Electron Reflector for MgZnO/CdSeTe/CdTe Solar Cells
摘要： Evolutionary algorithms (EAs) have been shown to be powerful tools for complex optimization problems, which are ubiquitous in both communication and big data analytics. This paper presents a new EA, namely negatively correlated search (NCS), which maintains multiple individual search processes in parallel and models the search behaviors of individual search processes as probability distributions. NCS explicitly promotes negatively correlated search behaviors by encouraging differences among the probability distributions (search behaviors). By this means, individual search processes share information and cooperate with each other to search diverse regions of a search space, which makes NCS a promising method for nonconvex optimization. The co-operation scheme of NCS could also be regarded as a novel diversity preservation scheme that, different from other existing schemes, directly promotes diversity at the level of search behaviors rather than merely trying to maintain diversity among candidate solutions. Empirical studies showed that NCS is competitive to well-established search methods in the sense that NCS achieved the best overall performance on 20 multimodal (nonconvex) continuous optimization problems. The advantages of NCS over state-of-the-art approaches are also demonstrated with a case study on the synthesis of unequally spaced linear antenna arrays.
关键词： Evolutionary algorithms,diversity maintenance,negative correlation,optimization in communication systems
更新于2025-09-16 10:30:52