scholarly journals What Is Considered a Variation of Biomechanical Parameters in Tensile Tests of Collagen-Rich Human Soft Tissues?—Critical Considerations Using the Human Cranial Dura Mater as a Representative Morpho-Mechanic Model

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 520
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Dura Mater ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Interquartile Range ◽  
Tissue Structure ◽  
Mechanical Parameters ◽  
Scanning Electron

Background and Objectives: Profound knowledge on the load-dependent behavior of human soft tissues is required for the development of suitable replacements as well as for realistic computer simulations. Regarding the former, e.g., the anisotropy of a particular biological tissue has to be represented with site- and direction-dependent particular mechanical values. Contrary to this concept of consistent mechanical properties of a defined soft tissue, mechanical parameters of soft tissues scatter considerably when being determined in tensile tests. In spite of numerous measures taken to standardize the mechanical testing of soft tissues, several setup- and tissue-related factors remain to influence the mechanical parameters of human soft tissues to a yet unknown extent. It is to date unclear if measurement extremes should be considered a variation or whether these data have to be deemed incorrect measurement outliers. This given study aimed to determine mechanical parameters of the human cranial dura mater as a model for human soft tissues using a highly standardized protocol and based on this, critically evaluate the definition for the term mechanical “variation” of human soft tissue. Materials and Methods: A total of 124 human dura mater samples with an age range of 3 weeks to 94 years were uniformly retrieved, osmotically adapted and mechanically tested using customized 3D-printed equipment in a quasi-static tensile testing setup. Scanning electron microscopy of 14 samples was conducted to relate the mechanical parameters to morphological features of the dura mater. Results: The here obtained mechanical parameters were scattered (elastic modulus = 46.06 MPa, interquartile range = 33.78 MPa; ultimate tensile strength = 5.56 MPa, interquartile range = 4.09 MPa; strain at maximum force = 16.58%, interquartile range = 4.81%). Scanning electron microscopy revealed a multi-layered nature of the dura mater with varying fiber directions between its outer and inner surface. Conclusions: It is concluded that mechanical parameters of soft tissues such as human dura mater are highly variable even if a highly standardized testing setup is involved. The tissue structure and composition appeared to be the main contributor to the scatter of the mechanical parameters. In consequence, mechanical variation of soft tissues can be defined as the extremes of a biomechanical parameter due to an uncontrollable change in tissue structure and/or the respective testing setup.

scholarly journals Exceptional preservation of soft tissue in a new specimen of Eoconfuciusornis and its biological implications

2017 ◽  
Vol 4 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Xiaoting Zheng ◽  
Jingmai K. O’Connor ◽  
Xiaoli Wang ◽  
Yanhong Pan ◽  
Yan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Soft Tissues ◽  
Support Network ◽  
Sexually Dimorphic ◽  
Remarkable Similarity ◽  
Exceptional Preservation ◽  
Internal Support ◽  
Scanning Electron

Abstract We report on an exceptional specimen of Eoconfuciusornis preserving rare soft-tissue traces of the ovary and wing. Ovarian follicles preserve a greater hierarchy than observed in Jeholornis and enantiornithines, suggesting confuciusornithiforms evolved higher rates of yolk deposition in parallel with the neornithine lineage. The preserved soft tissues of the wing indicate the presence of a propatagium and postpatagium, whereas an alular patagium is absent. Preserved remnants of the internal support network of the propatagium bear remarkable similarity to that of living birds. Soft tissue suggests the confuciusornithiform propatagium could maintain a cambered profile and generate lift. The feathers of the wing preserve remnants of their original patterning; however, this is not strongly reflected by observable differences under scanning electron microscopy (SEM). The tail plumage lacks elongate rectrices, suggesting that the earliest known confuciusornithiforms were sexually dimorphic in their plumage.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

Structure and mechanical properties of Ni/Ti multilayered composites produced by accumulative roll-bonding process

2019 ◽  
Vol 54 (8) ◽  
pp. 1119-1126
Author(s):  
Mohammad Mokhles ◽  
Morteza Hosseini ◽  
Habib Danesh-Manesh ◽  
Seyed Mojtaba Zebarjad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Accumulative Roll Bonding ◽  
Tensile Tests ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Roll Bonding ◽  
Multilayered Composites ◽  
Scanning Electron

This research studies the structure and mechanical properties of Ni/Ti multilayered composites produced from commercial pure Ni and Ti foils by accumulative roll-bonding technique. To investigate these properties, scanning electron microscopy, Vickers microhardness, and uniaxial tensile tests were conducted at different processing cycles. Studies showed that in terms of structure, Ni and Ti layers maintain their continuity even up to 10 cycles of accumulative roll-bonding. Moreover, the energy-dispersive spectroscopy in scanning electron microscopy detected no deformation induced diffusion or reactive interfacial zones. It was found that by increasing the accumulative roll-bonding cycles, tensile and yield strengths as well as the hardness of the composite enhance and the total elongation reduces continuously.

Analysis of Applicability of the Hollow Carbon Fibres for Self-Repairing Composites

2012 ◽  
Vol 729 ◽  
pp. 246-251 ◽  
Author(s):  
Sándor Kling ◽  
Tibor Czigány
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Single Fibre ◽  
Internal Diameter ◽  
Carbon Fibres ◽  
Hollow Carbon ◽  
Scanning Electron

The geometry and mechanical properties of solid and hollow carbon fibres were investigated by light-and scanning electron microscopy, and by single fibre tensile tests. The hollowness factor of fibres was determined by their external and internal diameter. The tensile strength was determined by single fibre tensile break tests. It was shown that the bigger the diameter of the fibres the lower the mechanical properties is. It was found that the hollow carbon fibres are suitable for preparation of a self-repairing composite with the advantage over other solutions because of their geometrical and mechanical properties.

Plastic embedding and surface erosion techniques in soft tissue scanning electron microscopy

1973 ◽  
Vol 99 (1) ◽  
pp. 69-74 ◽  
Author(s):  
I. G. S. Alexander ◽  
P. M. Capicchiano ◽  
B. C. Ritchie ◽  
J. E. Maloney
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Surface Erosion ◽  
Plastic Embedding ◽  
Scanning Electron

scholarly journals Preparation and Properties of Bacterial Cellulose/Alginate Blend Bio-Fibers

2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Shuai Zhang ◽  
Jin Luo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Hydrogen Bonds ◽  
Bacterial Cellulose ◽  
Tensile Tests ◽  
Intermolecular Hydrogen Bonds ◽  
Scanning Electron

LiOH/urea/thiourea aqueous systems have been successfully applied to the dissolution of bacterial cellulose (BC) and alginate (AL) to prepare blend fibers. Morphology, compatibility and mechanical properties of the blend fibers were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and tensile tests. The analyses indicated a good miscibility between alginate and bacterial cellulose, because of the strong interaction from the intermolecular hydrogen bonds. The mechanical properties of BC/AL blend fibers were significantly improved by introducing bacterial cellulose.

scholarly journals Solidification, Microstructure and Mechanical Properties of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr Cast Alloy with Erbium Addition

2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Microstructure Analysis ◽  
Cooling Curve ◽  
Scanning Electron

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.

Sign in / Sign up

Export Citation Format

Share Document