In vivo estimation of the Young’s modulus in normal human dermis

Fascicle length, pennation angle, and tendon elongation of the human tibialis anterior were measured in vivo by ultrasonography. Subjects ( n = 9) were requested to develop isometric dorsiflexion torque gradually up to maximal at the ankle joint angle of 20° plantarflexion from the anatomic position. Fascicle length shortened from 90 ± 7 to 76 ± 7 (SE) mm, pennation angle increased from 10 ± 1 to 12 ± 1°, and tendon elongation increased up to 15 ± 2 mm with graded force development up to maximum. The tendon stiffness increased with increasing tendon force from 10 N/mm at 0–20 N to 32 N/mm at 240–260 N. Young’s modulus increased from 157 MPa at 0–20 N to 530 MPa at 240–260 N. It can be concluded that, in isometric contractions of a human muscle, mechanical work, some of which is absorbed by the tendinous tissue, is generated by the shortening of muscle fibers and that ultrasonography can be used to determine the stiffness and Young’s modulus for human tendons.

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Low-frequency viscoelastic properties of canine femoral artery in vivo

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1979.236.5.h720 ◽

1979 ◽

Vol 236 (5) ◽

pp. H720-H724

Author(s):

P. Sipkema

Keyword(s):

Young’S Modulus ◽

Femoral Artery ◽

Constant Pressure ◽

Young's Modulus ◽

Low Frequency ◽

Absolute Value ◽

Average Value ◽

Mean Pressure ◽

Frequency Behavior

Mechanical properties of the canine femoral artery in vivo are measured as a function of frequency (0.0025--0.1 Hz) and as a function of mean pressure (10--16 kPa). Sinusoidal pressure variations are generated with a servo-controlled occluder system. The absolute value of the Young's modulus increases with mean pressure (E = 0.63 X 10(5) exp(0.211P)-N.m-2) at 0.05 Hz; where P is pressure. At heart rate frequencies (average value 2.22 Hz) this relation is: E = 1.25 X 10(5) exp(0.175P) N.m-2. The phase angle of the Young's modulus is independent of pressure at both frequencies. At 0.05 Hz we found: phi = 0.189 - 0.00788 P radians and at 2.22 Hz: phi = 0.0723 + 0.000428 P. The slope of both lines is not significantly different from zero slope (alpha = 0.05). Frequency dependence is studied at a constant pressure level (Pr, average value 14.3 kPa) just below the animals' mean pressure levels (average value 15.9 kPa). The frequency behavior of the elastic modulus is fitted with a function with two poles and two zeros (poles at 0.003 and 0.038 Hz; zeros at 0.0022 and 0.03 Hz).

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Mechanical Properties and Microarchitecture of Nanoporous Hydroxyapatite Bioceramic Nanoparticle Coatings on Ti and TiN

MRS Proceedings ◽

10.1557/proc-975-0975-dd06-15 ◽

2006 ◽

Vol 975 ◽

Author(s):

Andrei Stanishevsky ◽

Shafiul Chowdhury ◽

Nathaniel Greenstein ◽

Helene Yockell-Lelievre ◽

Jari Koskinen

Keyword(s):

Mechanical Properties ◽

Young’S Modulus ◽

Young's Modulus ◽

Biological Response ◽

Dip Coating ◽

Nano Crystalline ◽

Ceramic Manufacturing ◽

Nanoparticle Coatings

ABSTRACTThe hydroxyapatite (HA) based bioceramic materials are usually prepared at high sintering temperatures to attain suitable mechanical properties. The sintering process usually results in a material which is compositionally and morphologically different from nonstoichiometric nano-crystalline HA phase of hard tissue. At the same time, HA particulates used as precursors in ceramic manufacturing are often very similar to the natural HA nanocrystals. It has been shown that synthetic nanoparticle HA (nanoHA) based materials improve the biological response in vitro and in vivo, but the information on mechanical properties of these materials is scarce.In this work we studied the HA nanoparticle (10 – 80 nm mean size) coatings with 30 – 70% porosity prepared by a dip-coating technique on Ti and TiN substrates. It has been found that the mechanical properties of HA nanoparticle coatings are strongly influenced by the initial size, morphology, and surface treatment of nanoparticles. The nanoindentation Young's modulus and hardness of as–deposited nanoHA coatings were in the range of 2.5 – 6.9 GPa and 80 – 230 MPa, respectively. The coatings were stable after annealing up to at least 600 °C, reaching the Young's modulus up to 23 GPa and hardness up to 540 MPa, as well as in simulated body fluids.

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Comparative investigations of in vitro and in vivo bioactivity of titanium vs. Ti–24Nb–4Zr–8Sn alloy before and after sandblasting and acid etching

RSC Advances ◽

10.1039/d0ra00280a ◽

2020 ◽

Vol 10 (40) ◽

pp. 23582-23591

Author(s):

Xin Liu ◽

Yumei Niu ◽

Weili Xie ◽

Daqing Wei ◽

Qing Du

Keyword(s):

Young’S Modulus ◽

Young's Modulus ◽

Stress Shielding ◽

Acid Etching ◽

Implant Material ◽

Before And After ◽

New Type

To avoid the failure of clinical surgery due to “stress shielding” and the loosening of an implant, a new type of alloy, Ti–24Nb–4Zr–8Sn (TNZS), with a low Young's modulus acted as a new implant material in this work.

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Noninvasive Young's modulus visualization of fibrosis progression and delineation of pancreatic ductal adenocarcinoma (PDAC) tumors using Harmonic Motion Elastography (HME) in vivo

Theranostics ◽

10.7150/thno.37965 ◽

2020 ◽

Vol 10 (10) ◽

pp. 4614-4626 ◽

Cited By ~ 1

Author(s):

Alireza Nabavizadeh ◽

Thomas Payen ◽

Alina C. Iuga ◽

Irina R. Sagalovskiy ◽

Deborah Desrouilleres ◽

...

Keyword(s):

Pancreatic Ductal Adenocarcinoma ◽

Young’S Modulus ◽

Young's Modulus ◽

Ductal Adenocarcinoma ◽

Harmonic Motion ◽

Fibrosis Progression

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On the in Vivo Estimation of the Corneal Young’s Modulus

JOJ Ophthalmology ◽

10.19080/jojo.2017.05.555670 ◽

2017 ◽

Vol 5 (4) ◽

Author(s):

Jia Yush Yen

Keyword(s):

Young’S Modulus ◽

Young's Modulus

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Modifications of the mechanical properties of in vivo tissue-engineered vascular grafts by chemical treatments for a short duration

PLoS ONE ◽

10.1371/journal.pone.0248346 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0248346

Author(s):

Tomoya Inoue ◽

Keiichi Kanda ◽

Masashi Yamanami ◽

Daisuke Kami ◽

Satoshi Gojo ◽

...

Keyword(s):

Mechanical Properties ◽

Young’S Modulus ◽

Short Duration ◽

Young's Modulus ◽

Vascular Grafts ◽

Ultimate Strain ◽

Burst Pressure ◽

Chemical Treatments ◽

Retention Strength

In vivo tissue-engineered vascular grafts constructed in the subcutaneous spaces of graft recipients have functioned well clinically. Because the formation of vascular graft tissues depends on several recipient conditions, chemical pretreatments, such as dehydration by ethanol (ET) or crosslinking by glutaraldehyde (GA), have been attempted to improve the initial mechanical durability of the tissues. Here, we compared the effects of short-duration (10 min) chemical treatments on the mechanical properties of tissues. Tubular tissues (internal diameter, 5 mm) constructed in the subcutaneous tissues of beagle dogs (4 weeks, n = 3), were classified into three groups: raw tissue without any treatment (RAW), tissue dehydrated with 70% ET (ET), and tissue crosslinked with 0.6% GA (GA). Five mechanical parameters were measured: burst pressure, suture retention strength, ultimate tensile strength (UTS), ultimate strain (%), and Young’s modulus. The tissues were also autologously re-embedded into the subcutaneous spaces of the same dogs for 4 weeks (n = 2) for the evaluation of histological responses. The burst pressure of the RAW group (1275.9 ± 254.0 mm Hg) was significantly lower than those of ET (2115.1 ± 262.2 mm Hg, p = 0.0298) and GA (2570.5 ± 282.6 mm Hg, p = 0.0017) groups. Suture retention strength, UTS or the ultimate strain did not differ significantly among the groups. Young’s modulus of the ET group was the highest (RAW: 5.41 ± 1.16 MPa, ET: 12.28 ± 2.55 MPa, GA: 7.65 ± 1.18 MPa, p = 0.0185). No significant inflammatory tissue response or evidence of residual chemical toxicity was observed in samples implanted subcutaneously for four weeks. Therefore, short-duration ET and GA treatment might improve surgical handling and the mechanical properties of in vivo tissue-engineered vascular tissues to produce ideal grafts in terms of mechanical properties without interfering with histological responses.

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