Precise measurement of the configurational energy of bent graphene membranes via three-dimensional force field spectroscopy

2021 ◽  
Vol 104 (8) ◽  
Author(s):  
Makoto Ashino ◽  
Keita Nishioka ◽  
Keiji Hayashi ◽  
Roland Wiesendanger
Author(s):  
Joseph M. Iaquinto ◽  
Richard Tsai ◽  
Michael J. Fassbind ◽  
David R. Haynor ◽  
Bruce J. Sangeorzan ◽  
...  

The ability to accurately measure three dimensional (3D) bone kinematics is key to understanding the motion of the joints of the body, and how such motion is altered by injury, disease, and treatment. Precise measurement of such kinematics is technically challenging. Biplane fluoroscopy is ideally suited to measure bone motion. Such systems have been developed in the past for both radiographic stereo-photogrammetric analysis (RSA) [1] and the more challenging model-based analysis [2]. Research groups have studied the knee [3,4], shoulder [5] and ankle [6] motion with similar techniques. The work presented here is an initial evaluation of the performance of our system, i.e., a validation that this in-house system can detect magnitudes of motion on-par with other existing systems.


2021 ◽  
Vol 33 (3) ◽  
pp. 479-487
Author(s):  
Wei-wen Zhao ◽  
Chun-hui Ma ◽  
De-cheng Wan ◽  
Yi-qian Wang

2013 ◽  
Vol 48 (4) ◽  
pp. 141-145 ◽  
Author(s):  
Bartlomiej Oszczak ◽  
Eliza Sitnik

ABSTRACT During the process of satellite navigation, and also in the many tasks of classical positioning, we need to calculate the corrections to the initial (or approximate) location of the point using precise measurement of distances to the permanent points of reference (reference points). In this paper the authors have provided a way of developing Hausbrandt's equations, on the basis of which the exact coordinates of the point in two-dimensional space can be determined by using the computed correction to the coordinates of the auxiliary point. The authors developed generalised equations for threedimensional space introducing additional fixed point and have presented proof of derived formulas.


2013 ◽  
Vol 333-335 ◽  
pp. 199-206
Author(s):  
Chuan Wang ◽  
Jie Yang ◽  
Yan Wei Zhou

A method of measuring the radius of circular parts by binocular stereo vision technology is proposed. First of all the interior and exterior parameters of cameras are acquired by the camera calibration technology. Then the epipolar constraint can be calculated which contains the calibrated information. The image matching which uses the epipolar constraint is done to find the matching points. The three dimensional (3D) coordinates of edges points are reconstructed through trigonometry reconstruction. At last the analytic expression of the plane in which the circle lies and the circles radius are calculated in two steps by Levenberg-Marquardt (LM) algorithm. The proposed method does not require the prior knowledge of position between the measuring plane and the calibration plane which monocular measurement needs. Experimental results show that the measurement has high precision.


2009 ◽  
Vol 20 (26) ◽  
pp. 264004 ◽  
Author(s):  
D-A Braun ◽  
D Weiner ◽  
B Such ◽  
H Fuchs ◽  
A Schirmeisen

2019 ◽  
Author(s):  
Martin Lepsik ◽  
Roman Sommer ◽  
Sakonwan Kuhaudomlarp ◽  
Mickaёl Lelimousin ◽  
Emanuele Paci ◽  
...  

ABSTRACTPathogenic micro-organisms utilize protein receptors in adhesion to host tissues, a process that in some cases relies on the interaction between lectin and human glycoconjugates. Oligosaccharide epitopes are recognized through their three-dimensional structure and their flexibility is a key issue in specificity. In this paper, we analyse by X-ray crystallography the structures of the lectin LecB from two strains of Pseudomonas aeruginosa in complex with Lewis x oligosaccharide present on cell surfaces of human tissues. An unusual conformation of the glycan was observed in all binding sites with a non-canonical syn orientation of the N-acetyl group of N-acetyl-glucosamine. A PDB-wide search revealed that such an orientation occurs only in 2% of protein/carbohydrate complexes. Theoretical chemistry calculations showed that the observed conformation is unstable in solution but stabilised by the lectin. A reliable description of LecB/Lewis x complex by force field-based methods had proven as especially challenging due to the special feature of the binding site, two closely apposed Ca2+ ions which induce strong charge delocalisation. By comparing various force-field parametrisations, we design general protocols which will be useful in near future for designing carbohydrate-based ligands (glycodrugs) against other calcium-dependent protein receptors.


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