scholarly journals Surpassing the physical Nyquist limit to produce super-resolution cryo-EM reconstructions

2019 ◽  
Author(s):  
J. Ryan Feathers ◽  
Katherine A. Spoth ◽  
J. Christopher Fromme
Keyword(s):  
Super Resolution ◽  
Sampling Frequency ◽  
Potential Utility ◽  
Jack Bean Urease ◽  
Nyquist Frequency ◽  
Jack Bean ◽  
Resolution Imaging ◽  
Nyquist Limit ◽  
Resolution Single ◽  
Do So

AbstractThe resolution of cryo-EM reconstructions is fundamentally limited by the Nyquist frequency, which is half the sampling frequency of the detector and depends upon the magnification used. In principle, super-resolution imaging should enable reconstructions to surpass the physical Nyquist limit by increasing sampling frequency, yet there are no reports of reconstructions that do so. Here we report the use of super-resolution imaging with the K3 direct electron detector to produce super-resolution single-particle cryo-EM reconstructions significantly surpassing the physical Nyquist limit. We also present a comparative analysis of a sample imaged at four different magnifications. This analysis demonstrates that lower magnifications can be beneficial, despite the loss of higher resolution signal, due to the increased particle numbers imaged. To highlight the potential utility of lower magnification data collection, we produced a 3.5 Å reconstruction of jack bean urease with particles from a single micrograph.Abstract Figure

Revealing dynamically-organized receptor ion channel clusters in live cells by a correlated electric recording and super-resolution single-molecule imaging approach

2018 ◽  
Vol 20 (12) ◽  
pp. 8088-8098 ◽  
Author(s):  
Rajeev Yadav ◽  
H. Peter Lu
Keyword(s):  
Ion Channel ◽  
Single Molecule ◽  
Super Resolution ◽  
Live Cells ◽  
Imaging Approach ◽  
Resolution Imaging ◽  
Function Relationship ◽  
Bleaching Step ◽  
Relationship Of ◽  
Resolution Single

Correlating single-molecule fluorescence photo-bleaching step analysis and single-molecule super-resolution imaging, our findings for the clustering effect of the NMDA receptor ion channel on the live cell membranes provide a new and significant understanding of the structure–function relationship of NMDA receptors.

scholarly journals A H-bond strategy to develop acid-resistant photoswitchable rhodamine spirolactams for super-resolution single-molecule localization microscopy

2019 ◽  
Vol 10 (18) ◽  
pp. 4914-4922 ◽  
Author(s):  
Qingkai Qi ◽  
Weijie Chi ◽  
Yuanyuan Li ◽  
Qinglong Qiao ◽  
Jie Chen ◽  
...  
Keyword(s):  
Single Molecule ◽  
Super Resolution ◽  
Amino Groups ◽  
Localization Microscopy ◽  
Resolution Imaging ◽  
Resolution Single ◽  
Single Molecule Localization Microscopy

Rhodamine spirolactams with adjacent amino groups work as acid-resistant and photoswitchable fluorophores in single-molecule localization super-resolution imaging.

scholarly journals Photobleaching of YOYO-1 in super-resolution single DNA fluorescence imaging

2017 ◽  
Vol 8 ◽  
pp. 2296-2306 ◽  
Author(s):  
Joseph R Pyle ◽  
Jixin Chen
Keyword(s):  
Power Density ◽  
Super Resolution ◽  
Dna Structures ◽  
Single Dna Molecules ◽  
Video Acquisition ◽  
Nanoscale Topography ◽  
Excitation Laser ◽  
Resolution Imaging ◽  
Resolution Single

Super-resolution imaging of single DNA molecules via point accumulation for imaging in nanoscale topography (PAINT) has great potential to visualize fine DNA structures with nanometer resolution. In a typical PAINT video acquisition, dye molecules (YOYO-1) in solution sparsely bind to the target surfaces (DNA) whose locations can be mathematically determined by fitting their fluorescent point spread function. Many YOYO-1 molecules intercalate into DNA and remain there during imaging, and most of them have to be temporarily or permanently fluorescently bleached, often stochastically, to allow for the visualization of a few fluorescent events per DNA per frame of the video. Thus, controlling the fluorescence on–off rate is important in PAINT. In this paper, we study the photobleaching of YOYO-1 and its correlation with the quality of the PAINT images. At a low excitation laser power density, the photobleaching of YOYO-1 is too slow and a minimum required power density was identified, which can be theoretically predicted with the proposed method in this report.

scholarly journals Fast Target Localization Method for FMCW MIMO Radar via VDSR Neural Network

2021 ◽  
Vol 13 (10) ◽  
pp. 1956
Author(s):  
Jingyu Cong ◽  
Xianpeng Wang ◽  
Xiang Lan ◽  
Mengxing Huang ◽  
Liangtian Wan
Keyword(s):  
Neural Network ◽  
Continuous Wave ◽  
Super Resolution ◽  
Mimo Radar ◽  
Target Localization ◽  
Estimation Accuracy ◽  
Low Resolution ◽  
Range Estimation ◽  
Resolution Image ◽  
Resolution Imaging

The traditional frequency-modulated continuous wave (FMCW) multiple-input multiple-output (MIMO) radar two-dimensional (2D) super-resolution (SR) estimation algorithm for target localization has high computational complexity, which runs counter to the increasing demand for real-time radar imaging. In this paper, a fast joint direction-of-arrival (DOA) and range estimation framework for target localization is proposed; it utilizes a very deep super-resolution (VDSR) neural network (NN) framework to accelerate the imaging process while ensuring estimation accuracy. Firstly, we propose a fast low-resolution imaging algorithm based on the Nystrom method. The approximate signal subspace matrix is obtained from partial data, and low-resolution imaging is performed on a low-density grid. Then, the bicubic interpolation algorithm is used to expand the low-resolution image to the desired dimensions. Next, the deep SR network is used to obtain the high-resolution image, and the final joint DOA and range estimation is achieved based on the reconstructed image. Simulations and experiments were carried out to validate the computational efficiency and effectiveness of the proposed framework.

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