scholarly journals Modulating physical properties of porcine urethra with injection of novel biomimetic proteoglycans ex vivo

2019 ◽  
Vol 9 (4) ◽  
pp. 20190013 ◽  
Author(s):  
Alicia S. Kriete ◽  
Katsiaryna Prudnikova ◽  
Michele S. Marcolongo
Keyword(s):  
Urinary Incontinence ◽  
Physical Properties ◽  
Young’S Modulus ◽  
Water Uptake ◽  
Ex Vivo ◽  
Young's Modulus ◽  
Radial Expansion ◽  
Significant Difference ◽  
Testing Data ◽  
Phosphate Buffered Saline

Urinary incontinence is a significant challenge for women who are affected by it. We propose augmenting the tissue structure to restore normal biomechanics by molecularly engineering the tissue using a novel family of biomimetic proteoglycans (BPGs). This work examines the ability of BPGs to modulate the mechanical and physical properties of porcine urethras ex vivo to determine the feasibility of BPGs to be implemented as molecular treatment for stress urinary incontinence (SUI). We investigated compliance by performing a unique radial expansion testing method using urethras from six- to nine-month-old pigs. The urethras were injected with 0.5 ml BPG solution at three sites every approximately 120° (conc.: 25 mg ml −1 , 50 mg ml −1 and 75 mg ml −1 in 1× phosphate-buffered saline (PBS); n = 4 per group) and compared them with PBS-injected controls. Young's modulus was calculated by treating the urethra as a thin-walled pressure vessel. A water uptake study was performed by soaking 10 mm urethra biopsy samples that were injected with 0.1 ml BPG solution (conc.: 50 mg ml −1 , 100 mg ml −1 and 200 mg ml −1 in 1× PBS; n = 6 per group) in 5 ml PBS for 24 h. Although there was no significant difference in Young's modulus data, there were differences between groups as can be seen in the raw radial expansion testing data. Results showed that BPGs have the potential to increase hydration in samples, and that there was a significant difference in water uptake between BPG-injected samples and the controls (100 mg ml −1 samples versus PBS samples, p < 0.05). This work shows that BPGs have the potential to be implemented as a molecular treatment for SUI, by restoring the diminished proteoglycan content and subsequently increasing hydration and improving the compliance of urethral tissue.

scholarly journals Elasticity Changes in the Crystalline Lens during Oxidative Damage and the Antioxidant Effect of Alpha-Lipoic Acid Measured by Optical Coherence Elastography

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 207
Author(s):  
Hongqiu Zhang ◽  
Manmohan Singh ◽  
Achuth Nair ◽  
Kirill V. Larin ◽  
Salavat R. Aglyamov
Keyword(s):  
Oxidative Damage ◽  
Young’S Modulus ◽  
Lipoic Acid ◽  
Ex Vivo ◽  
Young's Modulus ◽  
Crystalline Lens ◽  
Biomechanical Properties ◽  
Optical Coherence ◽  
Age Related ◽  
Significant Difference

Age-related cataracts are one of the most prevalent causes of visual impairment around the world. Understanding the mechanisms of cataract development and progression is essential to enable early clinical diagnosis and treatment to preserve visual acuity. Reductive chemicals are potential medicines effective on cataract treatment. In this work, we investigated the cataract-induced oxidative damage in the crystalline lens and a kind of reductant, α-lipoic acid (ALA), ability to reduce the damage. We created oxidative environment to investigate the relationship between the progression of oxidative cataract and lenticular biomechanical properties measured by dynamic optical coherence elastography in porcine crystalline lenses ex vivo. The efficacy of ALA to minimize the stiffening of the lens was also quantified. The results showed a significant increase in Young’s modulus of the lens due to the formation of the oxidative cataract. We found a statistically significant difference between Young’s modulus of the lenses stored in phosphate-buffered saline and ALA solution after incubation in H2O2 solution for 3 h (43.0 ± 9.0 kPa versus 20.7 ± 3.5 kPa, respectively). These results show that the lens stiffness increases during oxidative cataract formation, and ALA has the potential to reverse stiffening of the lens caused by oxidative damage.

scholarly journals A study into the structure and physical properties of the Cr18Ni9-grade steel following long-term irradiation as part of the BN-600 reactor internals

2020 ◽  
Vol 6 (1) ◽  
pp. 1-6
Author(s):  
Irina A. Portnykh ◽  
Aleksandr V. Kozlov ◽  
Valery L. Panchenko ◽  
Vyacheslav S. Shikhalev
Keyword(s):  
Physical Properties ◽  
Young’S Modulus ◽  
Structural Changes ◽  
Young's Modulus ◽  
Void Size ◽  
Initial State ◽  
Porosity Distribution ◽  
Grade Steel ◽  
Reactor Internals

The microstructures and physical properties of the austenitic Cr18Ni9-grade steel after 22 and 33 years of operation as part of the reactor internals were tested for assessing the conditions of the BN-600 reactor non-replaceable components (internals) and the potential of their subsequent use in predicting the reactor ultimate life. The paper presents histograms of the porosity distribution depending on the void size, in samples taken from portions that were subjected to neutron irradiation with displacement rates ranging from 1.0×10–9 to 4.3×10–8 dpa/s at temperatures from 370 to 440 °C. The elasticity characteristics were measured by resonance-type ultrasonic technique for the samples taken from the same portions of material. It was demonstrated that swelling calculated using the histograms of the porosity distribution depending on the void size has the maximum value at ~415 °C and after 33 years of irradiation reaches values of ~3%. Long-term variations of Young’s modulus demonstrate non-monotonous dependence on the damage dose. The maximum relative variation of Young’s modulus after 22 and 33 years of operation does not exceed 2% and 6%, respectively, of the values corresponding to the initial state. It was shown that along with the irradiation-induced swelling the changes in the physical properties are also affected in the process of irradiation by other structural changes and, in particular, by the formation of secondary phases. As shown by the results of the studies, operation of the BN-600 reactor internals made of Cr18Ni9-grade steel can be extended beyond 33 years of service. The comparison of the results obtained for the material after 22 and 33 years of operation contains information required for describing subsequent changes of the structure and properties of the Cr18Ni9 internals. The obtained results can be used for forecasting the reactor ultimate life within the framework of existing and developed models.

Combination of ultrasonic elastography and Ki-67 index as a novel predictive modality for the prognosis in clinic stage III breast cancer

2019 ◽  
Author(s):  
Rui Du ◽  
Weiwei Shu ◽  
Baoding Chen ◽  
Xin Zhang ◽  
Xincai Wu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Cox Model ◽  
Strain Ratio ◽  
Survival Prediction ◽  
Concordance Index ◽  
Ki 67 ◽  
Significant Difference

Abstract Background To investigate the feasibility of combination of ultrasonic elastography (UE) and Ki-67 index as a novel predictive modality for the prognosis of clinic stage Ⅲ breast cancer. Methods Of 112 patients, Multi-parameter of UE were obtained after analyzing elastograms of 112 lesions which were recorded classification of Ki-67 by histopathologic diagnosis. Multivariate Survival analysis was performed by using multivariate Cox model. The nomograms was established to predict the probability of clinic stage Ⅲ breast cancer according to the selected independently significant variables in the multivariate Cox model. The model was internally validated using Harrell’s concordance index. Results ⅢC had significant difference in all ultrasonic elastography (UE) parameters (P < 0.05) and were statistically different from ⅢA and ⅢB (P < 0.01). The Cox model was RR (t)= Exp(1.104* X1+0.901*X4+0.972*X5) (X1: classification of Ki-67, X4: classification of strain ratio, X5: classification of Young's modulus). The nomogram showed that Ki-67 had the greatest influence on survival prediction, followed by Young's modulus and strain ratio. Internal validation revealed a concordance index of 0.76. Conclusions Our study explored a novel modality in predicting the prognosis of clinic stage Ⅲ breast cancer combining a tumor marker with breast UE imaging. A nomogram was developed to prove that the model was helpful to estimate the 5-year survival of the patients.

Significance of the heating rate on the physical properties of carbonized maple wood

Holzforschung ◽  
2008 ◽  
Vol 62 (5) ◽  
Author(s):  
Xinfeng Xie ◽  
Barry Goodell ◽  
Yuhui Qian ◽  
Michael Peterson ◽  
Jody Jellison
Keyword(s):  
Electrical Resistivity ◽  
Physical Properties ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Young's Modulus ◽  
Slow Heating ◽  
Graphene Sheets ◽  
Heating Rates ◽  
Cross Sectional ◽  
Carbonized Wood

Abstract Effects of the heating rate on the physical properties of carbonized wood were investigated by comparing the dimensional shrinkage, electrical resistivity, Young's modulus, and the evolution of turbostratic crystallites in maple hardwood samples carbonized at 600°C, 800°C, and 1000°C under heating regimes of 3°C h-1 and 60°C h-1. Important carbonized wood properties that developed at high temperature and high heating rates could also be produced at slow heating rates and lower temperatures. Furthermore, slow heating rates promoted the formation and growth of graphene sheets in turbostratic crystallites, which had a significant influence on the electrical resistivity and Young's modulus of the carbonized wood. The results indicate that the graphene sheets of turbostratic crystallites formed during wood carbonization were arranged parallel to the axial direction of wood cells and at an angle to the circumference of wood cells in the cross-sectional plane. With regard to the production of carbon products, a decrease in the heating rate may be beneficial for char properties and the prevention of crack production during manufacture of large monolithic carbon specimens from wood and wood-based materials.

Comparison of Microstructure and Mechanical Properties of Aluminum Components Manufactured by CMT

2017 ◽  
Vol 898 ◽  
pp. 1318-1324 ◽  
Author(s):  
Y. Zhao ◽  
Jian Xiao ◽  
S.J. Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ultrasonic Method ◽  
Fusion Line ◽  
Al Alloy ◽  
Continuous Growth ◽  
Line Region ◽  
Significant Difference

This paper presents an investigation on the microstructure and mechanical property of Al-alloy parts made by using additive manufacturing based on CMT (Cold Metal Transfer) welding technology. With the same 3D model and process parameters, a set of hollow cylindrical parts with 100 layers were built up using 2319, 4043, 5356 aluminum welding wires, respectively. Then their microstructure, tensile strength, and microhardness were tested and analyzed comparatively. The layer bands characteristics were obviously observed in both 2319 and 4043 parts. In the interlayer region of the 2319 parts, the segregation of alloying elements on the grain boundaries and inside the grains were significantly more than that in the fusion line region. For the microstructure of 4043 parts, the dendrites grow upward from the bottom without interruption in the fusion line region, and the continuous growth structure was maintained. There is no obviously change on the microhardness from the bottom to the top because the organization is uniform and there is no significant difference in the grain size. The ultimate strength and elongation in the horizontal direction were higher than those in the longitudinal direction, and the 5356 parts had best mechanical properties among the three materials. Ultrasonic method was also used to measure the Young's modulus of the additive manufactured parts. The Young's modulus measuring results were accordant with the results obtained by the mechanical property testing, and the error was within 3%.

MECHANICAL PROPERTIES OF CHORDAE TENDINEAE OF THE MITRAL HEART VALVE: YOUNG'S MODULUS, STRUCTURAL STIFFNESS, AND EFFECTS OF AGING

2011 ◽  
Vol 11 (01) ◽  
pp. 221-230 ◽  
Author(s):  
LAURA MILLARD ◽  
DANIEL M. ESPINO ◽  
DUNCAN E. T. SHEPHERD ◽  
DAVID W. L. HUKINS ◽  
KEITH G. BUCHAN
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Finite Element Models ◽  
Structural Stiffness ◽  
Posterior Leaflet ◽  
Chordae Tendineae ◽  
Significant Difference ◽  
Valve Function ◽  
Effects Of Aging

Young's modulus and structural stiffness were determined for chordae tendineae of the mitral valve from young (18–26 weeks) and old (over 2 years) porcine hearts. For chordae from the posterior leaflet of the valve, the Young's modulus values were significantly higher (p < 0.05) for the thinner marginal chordae (59 ± 31 MPa young; 88 ± 21 MPa old) than for the thicker basal chordae (31 ± 4 MPa young; 28 ± 9 MPa old). Marginal chordae (both anterior and posterior) had significantly higher (p < 0.05) value for their Young's modulus in old (88 ± 21 MPa anterior and posterior) than in young (62 ± 17 MPa anterior, 59 ± 18 MPa posterior) pig hearts. There was no significant difference in structural stiffness between marginal and basal (anterior and posterior leaflets) or between strut chordae (that are associated with anterior the leaflet only) and marginal and basal chordae. However, the value of structural stiffness of chordae was significantly higher (p < 0.05) for old (2.2 ± 0.2 kN/m) than for young (2.0 ± 0.4 kN/m) chordae. These results show that aging affects the properties of chordae and that all chordae need to be included in finite element models of valve function.

scholarly journals Spatio-temporal development of the endothelial glycocalyx layer and its mechanical property in vitro

2012 ◽  
Vol 9 (74) ◽  
pp. 2290-2298 ◽  
Author(s):  
Ke Bai ◽  
Wen Wang
Keyword(s):  
Endothelial Cells ◽  
Cell Membrane ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Umbilical Vein ◽  
Endothelial Glycocalyx ◽  
Temporal Development ◽  
Afm Indentation ◽  
Significant Difference

The endothelial glycocalyx is a thin layer of polysaccharide matrix on the luminal surface of endothelial cells (ECs), which contains sulphated proteoglycans and glycoproteins. It is a mechanotransducer and functions as an amplifier of the shear stress on ECs. It controls the vessel permeability and mediates the blood–endothelium interaction. This study investigates the spatial distribution and temporal development of the glycocalyx on cultured ECs, and evaluates mechanical properties of the glycocalyx using atomic force microscopy (AFM) nano-indentation. The glycocalyx on human umbilical vein endothelial cells (HUVECs) is observed under a confocal microscope. Manipulation of the glycocalyx is achieved using heparanase or neuraminidase. The Young's modulus of the cell membrane is calculated from the force–distance curve during AFM indentation. Results show that the glycocalyx appears predominantly on the edge of cells in the early days in culture, e.g. up to day 5 after seeding. On day 7, the glycocalyx is also seen in the apical area of the cell membrane. The thickness of the glycocalyx is approximately 300 nm–1 μm. AFM indentation reveals the Young's modulus of the cell membrane decreases from day 3 (2.93 ± 1.16 kPa) to day 14 (0.35 ± 0.15 kPa) and remains unchanged to day 21 (0.33 ± 0.19 kPa). Significant difference in the Young's modulus is also seen between the apical (1.54 ± 0.58 kPa) and the edge (0.69 ± 0.55 kPa) of cells at day 7. By contrast, neuraminidase-treated cells (i.e. without the glycocalyx) have similar values between day 3 (3.18 ± 0.88 kPa), day 14 (2.12 ± 0.78 kPa) and day 21 (2.15 ± 0.48 kPa). The endothelial glycocalyx in vitro shows temporal development in the early days in culture. It covers predominantly the edge of cells initially and appears on the apical membrane of cells as time progresses. The Young's modulus of the glycocalyx is deduced from Young's moduli of cell membranes with and without the glycocalyx layer. Our results show the glycocalyx on cultured HUVECs has a Young's modulus of approximately 0.39 kPa.

scholarly journals The influence of stress and strain on the physical properties of matter. Part I. Moduli of elasticity— continued . Relations between moduli of elasticity, thermal capacity, and other physical constants

1885 ◽  
Vol 38 (235-238) ◽  
pp. 488-500 ◽  
Keyword(s):  
Physical Properties ◽  
Young’S Modulus ◽  
Solid Body ◽  
Young's Modulus ◽  
Thermal Capacity ◽  
Stress And Strain ◽  
Physical Constants ◽  
The Mean ◽  
Moduli Of Elasticity

It has been proved by Wertheim, whose results have been verified by myself, that if e be taken to denote “Young’s Modulus,” and α the mean distance between the centres of any two adjacent molecules of a solid body, e x α 7 is, in the case of most metals, approximately a constant.

scholarly journals Braiding Thermoplastic and Glass Fibers in Composite Dental Post Improves Their Mechanical Compatibility, In Vitro Experiment

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2294
Author(s):  
Esraa M. Abdelkader ◽  
Khaled Nassar ◽  
Juan Melchor ◽  
Guillermo Rus
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Ex Vivo ◽  
Young's Modulus ◽  
Glass Fibers ◽  
P Wave ◽  
Fiber Volume ◽  
Mechanical Compatibility

Mechanical compatibility with the human dentin is a considerable issue when fabricating dental fiber posts. To this purpose, this study introduces a new method of fabricating compatible dental posts using braiding techniques of thermoplastic fibers (matrix) with glass fibers (reinforcement). Fifty fiber-reinforced composite (FRC) posts of thermoplastic yarns polypropylene (PP) braided with continuous filaments glass fibers (GFs) for reinforcement, varying in fiber volume fraction (FVF), and core types are fabricated and tested. Posts are performed using a braiding machine, and braids are placed in an aluminum mold. The filled mold is playced inside an oven at the melting temperature of the polypropylene to produce the final post’s shape. An ultrasonic test is conducted to measure the shear modulus and Young’s modulus of FRC post specimens by measuring the velocities of both the P-wave and S-wave. In order to ensure the accuracy of the measurements, each sample is measured three times, and then the means and standard deviations of each sample are calculated before analyzing the test results using the means of two steps, namely, clustering and comparing the P and R² values of each cluster, which revealed that FVF, fiber mass, and core type of the specimen had a significant effect on the resulted Young’s and shear modulus. The results indicate that the proposed method can fabricate competitive dental posts with regard to different fabricating variables. The samples show Young’s modulus ranges of from 10.08 GPa to 31.83 GPa. The following tested hypothesis is supported: the braiding technique of thermoplastic fibers with glass fibers will improve the mechanical compatibility of the resulting posts (ex vivo).

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