scholarly journals Microstructural deformation observed by Mueller polarimetry during traction assay on myocardium samples

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicole Tueni ◽  
Jérémy Vizet ◽  
Martin Genet ◽  
Angelo Pierangelo ◽  
Jean-Marc Allain
Keyword(s):  
Mechanical Response ◽  
Three Dimensional ◽  
Full Field ◽  
Tissue Scattering ◽  
Traction Device ◽  
First Time ◽  
Heart Wall ◽  
Mechanical Traction ◽  
Collagen Layer

AbstractDespite recent advances, the myocardial microstructure remains imperfectly understood. In particular, bundles of cardiomyocytes have been observed but their three-dimensional organisation remains debated and the associated mechanical consequences unknown. One of the major challenges remains to perform multiscale observations of the mechanical response of the heart wall. For this purpose, in this study, a full-field Mueller polarimetric imager (MPI) was combined, for the first time, with an in-situ traction device. The full-field MPI enables to obtain a macroscopic image of the explored tissue, while providing detailed information about its structure on a microscopic scale. Specifically it exploits the polarization of the light to determine various biophysical quantities related to the tissue scattering or anisotropy properties. Combined with a mechanical traction device, the full-field MPI allows to measure the evolution of such biophysical quantities during tissue stretch. We observe separation lines on the tissue, which are associated with a fast variation of the fiber orientation, and have the size of cardiomyocyte bundles. Thus, we hypothesize that these lines are the perimysium, the collagen layer surrounding these bundles. During the mechanical traction, we observe two mechanisms simultaneously. On one hand, the azimuth shows an affine behavior, meaning the orientation changes according to the tissue deformation, and showing coherence in the tissue. On the other hand, the separation lines appear to be resistant in shear and compression but weak against traction, with a forming of gaps in the tissue.

scholarly journals Galactography with Tomosynthesis Technique (Galactomosynthesis) – Renaissance of a Method?

2018 ◽  
Vol 78 (05) ◽  
pp. 493-498 ◽  
Author(s):  
Rüdiger Schulz-Wendtland ◽  
Caroline Preuss ◽  
Peter Fasching ◽  
Christian Loehberg ◽  
Michael Lux ◽  
...  
Keyword(s):  
High Resolution ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Imaging Technique ◽  
Nipple Discharge ◽  
Full Field ◽  
Contrast Enhanced ◽  
First Time

Abstract Introduction For decades, conventional galactography was the only imaging technique capable of showing the mammary ducts. Today, diagnosis is based on a multimodal concept which combines high-resolution ultrasound with magnetic resonance (MR) mammography and ductoscopy/galactoscopy and has a sensitivity and specificity of up to 95%. This study used tomosynthesis in galactography for the first time and compared the synthetic digital 2D full-field mammograms generated with this technique with the images created using the established method of ductal sonography. Both methods should be able to detect invasive breast cancers and their precursors such as ductal carcinoma in situ (DCIS) as well as being able to identify benign findings. Material and Methods Five patients with pathological nipple discharge were examined using ductal sonography, contrast-enhanced 3D galactography with tomosynthesis and the synthetic digital 2D full-field mammograms generated with the latter method. Evaluation of the images created with the different imaging modalities was done by three investigators with varying levels of experience with complementary breast diagnostics (1, 5 and 15 years), and their evaluations were compared with the histological findings. Results All 3 investigators independently evaluated the images created with ductal sonography, contrast-enhanced 3D galactography with tomosynthesis, and generated synthetic digital 2D full-field mammograms. Their evaluations were compared with the histopathological assessment of the surgical specimens resected from the 5 patients. There was 1 case of invasive breast cancer, 2 cases with ductal carcinoma in situ and 2 cases with benign findings. All 3 investigators made more mistakes when they used the standard imaging technique of ductal sonography to diagnose suspicious lesions than when they used contrast-enhanced galactography with tomosynthesis and the generated synthetic digital 2D full-field mammograms. Conclusion This is the first time breast tomosynthesis was used in galactography (galactomosynthesis) to create digital 3-dimensional images of suspicious findings. When used together with the generated synthetic digital 2D full-field mammograms, it could be a useful complementary procedure for the diagnosis of breast anomalies and could herald a renaissance of this method. Compared with high-resolution ductal ultrasound, the investigators achieved better results with contrast-enhanced galactography using tomosynthesis and the generated synthetic digital 2D full-field mammograms, as confirmed by histopathological findings.

Zonal Poisson Effect on the Chondron Deformation in Articular Cartilage under Compression

2007 ◽  
Vol 342-343 ◽  
pp. 133-136
Author(s):  
Jae Bong Choi
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Pericellular Matrix ◽  
Poisson Effect ◽  
Type Vi Collagen ◽  
Confocal Images ◽  
Three Dimensional Models

The objective of this study was to quantify the zonal difference of the in situ chondron’s Poisson effect under different magnitudes of compression. Fluorescence immunolabeling for type VI collagen was used to identify the pericellular matrix (PCM) and chondron, and a series of fluorescent confocal images were recorded and reconstructed to form quantitative three-dimensional models. The zonal variations in the mechanical response of the chondron do not appear to be due to zonal differences in PCM properties, but rather seem to result from significant inhomogeneities in relative stiffnesses of the extracellular matrix (ECM) and PCM with depth.

scholarly journals Nonlinear mechanics of lamin filaments and the meshwork topology build an emergent nuclear lamina

2019 ◽  
Author(s):  
K. Tanuj Sapra ◽  
Zhao Qin ◽  
Anna Dubrovsky-Gaupp ◽  
Ueli Aebi ◽  
Daniel J. Müller ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Mechanical Stability ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Small World ◽  
Nuclear Lamina ◽  
Integrative Approach ◽  
Graph Theory Analysis ◽  
Dynamics Simulations

AbstractThe nuclear lamina – a meshwork of intermediate filaments termed lamins – functions as a mechanotransduction interface between the extracellular matrix and the nucleus via the cytoskeleton. Although lamins are primarily responsible for the mechanical stability of the nucleus in multicellular organisms, in situ characterization of lamin filaments under tension has remained elusive. Here, we apply an integrative approach combining atomic force microscopy, cryo-electron tomography, network analysis, and molecular dynamics simulations to directly measure the mechanical response of single lamin filaments in its three-dimensional meshwork. Endogenous lamin filaments portray non-Hookean behavior – they deform reversibly under a force of a few hundred picoNewtons and stiffen at nanoNewton forces. The filaments are extensible, strong and tough, similar to natural silk and superior to the synthetic polymer Kevlar®. Graph theory analysis shows that the lamin meshwork is not a random arrangement of filaments but the meshwork topology follows ‘small world’ properties. Our results suggest that the lamin filaments arrange to form a robust, emergent meshwork that dictates the mechanical properties of individual lamin filaments. The combined approach provides quantitative insights into the structure-function organization of lamins in situ, and implies a role of meshwork topology in laminopathies.

scholarly journals Strain Analysis on Electrochemical Failures of Nanoscale Silicon Electrode Based on Three-Dimensional In Situ Measurement

2020 ◽  
Vol 10 (2) ◽  
pp. 468 ◽  
Author(s):  
Zhifeng Qi ◽  
Zhongqiang Shan ◽  
Weihao Ma ◽  
Linan Li ◽  
Shibin Wang ◽  
...  
Keyword(s):  
Silicon Film ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Image Correlation ◽  
Mechanical Parameters ◽  
Stress Strain ◽  
Full Field ◽  
Battery Capacity

Nanoscale silicon film electrodes in Li-ion battery undergo great deformations leading to electrochemical and mechanical failures during repeated charging-discharging cycles. In-situ experimental characterization of the stress/strain in those electrodes still faces big challenges due to remarkable complexity of stress/strain evolution while it is still hard to predict the association between the electrode cycle life and the measurable mechanical parameters. To quantificationally investigate the evolution of the mechanical parameters, we develop a new full field 3D measurement method combining digital image correlation with laser confocal profilometry and propose a strain criterion of the failure based on semi-quantitative analysis via mean strain gradient (MSG). The experimental protocol and results illustrate that the revolution of MSG correlates positively with battery capacity decay, which may inspire future studies in the field of film electrodes.

scholarly journals Characterization of the crystal structure, kinematics, stresses and rotations in angular granular quartz during compaction

2018 ◽  
Vol 51 (4) ◽  
pp. 1021-1034 ◽  
Author(s):  
Ryan C. Hurley ◽  
Eric B. Herbold ◽  
Darren C. Pagan
Keyword(s):  
Crystal Structure ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Spherical Particles ◽  
X Ray ◽  
Porosity Evolution ◽  
Individual Grains ◽  
Particle Packings ◽  
Number Of Particles

Three-dimensional X-ray diffraction (3DXRD), a method for quantifying the position, orientation and elastic strain of large ensembles of single crystals, has recently emerged as an important tool for studying the mechanical response of granular materials during compaction. Applications have demonstrated the utility of 3DXRD and X-ray computed tomography (XRCT) for assessing strains, particle stresses and orientations, inter-particle contacts and forces, particle fracture mechanics, and porosity evolution in situ. Although past studies employing 3DXRD and XRCT have elucidated the mechanics of spherical particle packings and angular particle packings with a small number of particles, there has been limited effort to date in studying angular particle packings with a large number of particles and in comparing the mechanics of these packings with those composed of a large number of spherical particles. Therefore, the focus of the present paper is on the mechanics of several hundred angular particles during compaction using in situ 3DXRD to study the crystal structure, kinematics, stresses and rotations of angular quartz grains. Comparisons are also made between the compaction response of angular grains and that of spherical grains, and stress-induced twinning within individual grains is discussed.

scholarly journals Formation and annihilation of stressed deformation twins in magnesium

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Karim Louca ◽  
Hamidreza Abdolvand ◽  
Charles Mareau ◽  
Marta Majkut ◽  
Jonathan Wright
Keyword(s):  
Mechanical Response ◽  
Axial Stress ◽  
Three Dimensional ◽  
Service Performance ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
Sign Reversal ◽  
X Ray ◽  
Hexagonal Close Packed

AbstractThe mechanical response of polycrystalline materials to an externally applied load and their in-service performance depend on the local load partitioning among the constituent crystals. In hexagonal close-packed polycrystals such load partitioning is significantly affected by deformation twinning. Here we report in-situ compression-tension experiments conducted on magnesium specimens to measure the evolution of grain resolved tensorial stresses and formation and annihilation of twins. More than 13000 grains and 1300 twin-parent pairs are studied individually using three-dimensional synchrotron X-ray diffraction. It is shown that at the early stages of plasticity, the axial stress in twins is higher than that of parents, yet twins relax with further loading. While a sign reversal is observed for the resolved shear stress (RSS) acting on the twin habit plane in the parent, the sign of RSS within the majority of twins stays unchanged until twin annihilation during the load reversal. The variations of measured average stresses across parents and twins are also investigated.

scholarly journals Comprehensive histological imaging of native microbiota in human glioma

2021 ◽  
Author(s):  
Jiajia Zhao ◽  
Dian He ◽  
Hei Ming Lai ◽  
Yingying Xu ◽  
Yunhao Luo ◽  
...  
Keyword(s):  
Intercellular Space ◽  
Quantitative Imaging ◽  
Three Dimensional ◽  
Human Glioma ◽  
Microscopy Imaging ◽  
Nuclear Membranes ◽  
Tumor Tissues ◽  
Tumor Types ◽  
First Time

Abstract Mounting evidence suggests that distinct microbial communities reside in tumors and play important roles in tumor physiology. Recently, Nejman et al. profiled the composition and localization of intratumoral bacteria using 16S DNA sequencing and histological visualization methods across seven tumor types, including human glioblastoma. However, considering potential contamination in their sample origins and processing, the results based on traditional histological methods need to be validated. Here, we propose a three-dimensional (3D) intratumoral microbiota visualization and quantification protocol to observe microbiota in intact tumor tissues on the premise of avoiding possible contamination in the surface of tissues, based on tissue clearing, immunofluorescent labeling, microscopy imaging, and image processing. For the first time, we have achieved 3D quantitative imaging of bacterial LPS fluorescent signals deep in gliomas in a contamination-free manner, which was founded mostly localized near nuclear membranes or in the intercellular space. Through an automated statistical algorithm, reliable signals can be distinguished for further analysis of their sizes, distribution, and fluorescence intensities. Combining two-dimensional images from multiple thin-section histological methods, including immunochemistry and fluorescence in situ hybridization, we provide a comprehensive histological investigation of the morphology and distribution of these signals on human glioma samples. We expect that this multi-evidence chain will provide supporting proof for the presence of intratumoral bacteria in human glioma and that the integrated pipeline can be applied to investigate the native bacteria within diverse tumors and contribute to the interpretation of their direct roles in the tumor microenvironment.

Use of three-dimensional digital image correlation to evaluate mechanical response of prosthetic systems

2016 ◽  
Vol 41 (1) ◽  
pp. 101-105
Author(s):  
Michelin Alvarez-Camacho ◽  
Victor Alvarez-Guevara ◽  
Carlos Galvan Duque Gastelum ◽  
Daniel Flores Vazquez ◽  
Gerardo Rodriguez-Reyes ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Technical Note ◽  
Image Correlation ◽  
Patient Specific ◽  
Real Patient ◽  
Full Field ◽  
Measurement Protocol

Background and aim:The need of comfortable and safe prosthetic systems is an important challenge for both prosthetists and engineers. The aim of this technical note is to demonstrate the use of three-dimensional digital image correlation to evaluate mechanical response of two prosthetic systems under real patient dynamic loads.Technique:This note describes the use of three-dimensional digital image correlation method to obtain full-field strain and displacement measurements on the surface of two lower limb prostheses for Chopart amputation. It outlines key points of the measurement protocol and illustrates the analysis of critical regions using data obtained on specific points of interest.Discussion:The results show that the use of three-dimensional digital image correlation can be a tool for the prosthetist to optimize the prosthesis considering features related to the material and design, in order to bear with real patient-specific load conditions.Clinical relevanceThree-dimensional digital image correlation can support decision-making on new designs and materials for prosthetics based on quantitative data. Better understanding of mechanical response could also assist prescription for appropriate prosthetic systems.

Validation of Impact Simulations of a Car Bonnet by Full-Field Optical Measurements

2011 ◽  
Vol 70 ◽  
pp. 57-62
Author(s):  
George Lampeas ◽  
Vasilis Pasialis ◽  
Thorsten Siebert ◽  
Mara Feligiotti ◽  
Andrea Pipino
Keyword(s):  
Displacement Field ◽  
High Speed ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Quantitative Information ◽  
Image Correlation ◽  
Optical Measurements ◽  
Optical Techniques ◽  
Full Field ◽  
Dynamic Events

Innovative designs of transport vehicles need to be validated in order to demonstrate reliability and provide confidence. The most common approaches to such designs involve simulations based on Finite Element (FE) analysis, used to study the mechanical response of the structural elements during critical events. These simulations need reliable validation techniques, especially if anisotropic materials, such as fibre reinforced polymers, or complex designs, such as automotive components are considered. It is normal practice to assess the accuracy of numerical results by comparing the predicted values to corresponding experimental data. In this frame, the use of whole field optical techniques has been proven successful in the validation of deformation, strain, or vibration modes [1]. The strength of full-field optical techniques is that the whole displacement field can be visualized and analyzed. By using High Speed cameras, the Digital Image Correlation (DIC) method can be applied to highly non-linear dynamic events and deliver quantitative information about the three-dimensional displacement field [2].

scholarly journals Selective biodegradation of keratin matrix in feather rachis reveals classic bioengineering

2009 ◽  
Vol 277 (1685) ◽  
pp. 1161-1168 ◽  
Author(s):  
Theagarten Lingham-Soliar ◽  
Richard H. C. Bonser ◽  
James Wesley-Smith
Keyword(s):  
Close Association ◽  
Three Dimensional ◽  
Elastic Recoil ◽  
Keratin Filaments ◽  
Microbial Biodegradation ◽  
Major Structural Component ◽  
First Time ◽  
Fibre Matrix ◽  
New Location

Flight necessitates that the feather rachis is extremely tough and light. Yet, the crucial filamentous hierarchy of the rachis is unknown—study hindered by the tight chemical bonding between the filaments and matrix. We used novel microbial biodegradation to delineate the fibres of the rachidial cortex in situ . It revealed the thickest keratin filaments known to date (factor >10), approximately 6 µm thick, extending predominantly axially but with a small outer circumferential component. Near-periodic thickened nodes of the fibres are staggered with those in adjacent fibres in two- and three-dimensional planes, creating a fibre–matrix texture with high attributes for crack stopping and resistance to transverse cutting. Close association of the fibre layer with the underlying ‘spongy’ medulloid pith indicates the potential for higher buckling loads and greater elastic recoil. Strikingly, the fibres are similar in dimensions and form to the free filaments of the feather vane and plumulaceous and embryonic down, the syncitial barbules, but, identified for the first time in 140+ years of study in a new location—as a major structural component of the rachis. Early in feather evolution, syncitial barbules were consolidated in a robust central rachis, definitively characterizing the avian lineage of keratin.

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