Multimodale Beurteilung der Stabilität von Uterusnarbengewebe bei Z.n. Sectio caesarea – Young's modulus in-vivo und in-vitro – quantitative Sonografie und Zugdehnungsversuch

2015 ◽  
Vol 75 (05) ◽  
Author(s):  
G Seliger ◽  
K Chaoui ◽  
C Kunze ◽  
SD Costa ◽  
M Tchirikov
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Sectio Caesarea

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

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.

scholarly journals 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 ◽  
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.

scholarly journals Measurements of Young's Modulus of Elasticity of the Canine Aorta with Ultrasound

1979 ◽  
Vol 1 (4) ◽  
pp. 356-367 ◽  
Author(s):  
D.J. Hughes ◽  
C.F. Babbs ◽  
L.A. Geddes ◽  
J.D. Bourland
Keyword(s):  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Parietal Pleura ◽  
Young’S Modulus Of Elasticity ◽  
Blood Pressures ◽  
Canine Aorta

We have developed an ultrasonic technique for determining the dynamic Young's modulus of elasticity (E) of the canine aorta in vivo. Young's modulus was measured in the descending thoracic aorta (DTA) and the abdominal aorta (AA) of 12 dogs over a range of mean blood pressures from 40 – 200 mm Hg. The vessels were excised and dynamic moduli were determined in vitro post-mortem from pressure-volume curves. The data so obtained were compared to the in vivo values. In vivo and in vitro moduli increased exponentially with mean distending pressure (P). The equation of best fit for these data was of the form E = R0 exp(aP). E0 and a depend on the site of measurement (AA or DTA) and upon the particular animal. In vivo and in vitro moduli were not significantly different in the AA (AA: in vivo E0 = 667 ± 382 mm Hg, a = 0.017 ± 0.004 mm Hg-1 in vitro E0 = 888 ± 367, a = 0.016 ± 0.002). However, in vivo moduli exceeded in vitro moduli in the DTA. (DTA: in vivo E0 = 687 ± 241, a = 0.016 ± 0.004 in vitro E0 = 349 ± 64, a = 0.018 ± 0.003). The increased stiffness of the DTA compared to the AA in vivo may be due to the in situ tethering of the aorta to the spine by the parietal pleura.

Novel methodology to obtain salient biomechanical characteristics of insole materials

1997 ◽  
Vol 87 (6) ◽  
pp. 266-271 ◽  
Author(s):  
LA Lavery ◽  
SA Vela ◽  
HR Ashry ◽  
DR Lanctot ◽  
KA Athanasiou
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Scientific Information ◽  
Rate Of Change ◽  
Compressive Stiffness ◽  
Shock Absorbers ◽  
Time Integral ◽  
Pressure Time

Viscoelastic inserts are commonly used as artificial shock absorbers to prevent neuropathic foot ulcerations by decreasing pressure on the sole of the foot. Unfortunately, there is little scientific information available to guide physicians in the selection of appropriate insole materials. Therefore, a novel methodology was developed to form a rational platform for biomechanical characterizations of insole material durability, which consisted of in vivo gait analysis and in vitro bioengineering measurements. Results show significant differences in the compressive stiffness of the tested insoles and the rate of change over time in both compressive stiffness and peak pressures measured. Good correlations were found between pressure-time integral and Young's modulus (r2 = 0.93), and total energy applied and Young's modulus (r2 = 0.87).

Mechanical properties of human patellar tendon at the hierarchical levels of tendon and fibril

2012 ◽  
Vol 112 (3) ◽  
pp. 419-426 ◽  
Author(s):  
René B. Svensson ◽  
Philip Hansen ◽  
Tue Hassenkam ◽  
Bjarki T. Haraldsson ◽  
Per Aagaard ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Patellar Tendon ◽  
Young's Modulus ◽  
Hierarchical Structures ◽  
Collagen Fibrils ◽  
Cross Sectional ◽  
Hierarchical Levels

Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons ( n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than that of tendon supports that fibrillar rather than interfibrillar properties govern the subfailure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition to the primary work comparing the two hierarchical levels, we also verified the existence of viscoelastic behavior in isolated human collagen fibrils.

Osteoconductivity of Porous Titanium Having Young’s Modulus Similar to Bone and Surface Modification by OCP

2007 ◽  
Vol 330-332 ◽  
pp. 951-954 ◽  
Author(s):  
Yuko Suzuki ◽  
Naoyuki Nomura ◽  
Shuji Hanada ◽  
Shinji Kamakura ◽  
Takahisa Anada ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Porous Titanium ◽  
Mouse Bone Marrow ◽  
Calvarial Bone ◽  
Coating Agent ◽  
Porous Ti

The present study was designed to investigate whether porous titanium (Ti) having Young’s modulus similar to bone has osteoconductive characteristics in rat critical-sized calvarial bone defect. The effect of coating by octacalcium phosphate (OCP) was also examined. OCP is known as a precursor of initial mineral crystals of biological apatite in bones and teeth. Ti powder was prepared by plasma rotating electrode process in an Ar atmosphere. Then, porous Ti disks, 8 mm in diameter with 1 mm thick, were obtained using the particles ranging from 300 to 500 +m, by sintering at 1573 K without applied pressure. The disks had about 35 vol% in porosity and about 10 GPa in Young’s modulus which corresponds to that of human cortical bone. Newly formed bone was observed so as to fill the pore up at 12 weeks, confirming the ability to conduct the ingrowths of the bone tissue. Although in vitro study showed that proliferation of mouse bone marrow stromal ST-2 cells was inhibited on the dishes coated by OCP rather than the control dish, OCP coating on porous Ti seemed to stimulate the bone formation in vivo. Taken together, it seems likely that porous Ti having Young’s modulus similar to bone shows osteoconductive characteristics to conduct bone ingrowths. OCP could be a potential coating agent to assist bone regeneration on porous Ti.

scholarly journals Technical Note: In vivo Young's modulus mapping of pancreatic ductal adenocarcinoma during HIFU ablation using harmonic motion elastography ( HME )

2018 ◽  
Vol 45 (11) ◽  
pp. 5244-5250 ◽  
Author(s):  
Alireza Nabavizadeh ◽  
Thomas Payen ◽  
Niloufar Saharkhiz ◽  
Matthew McGarry ◽  
Kenneth P. Olive ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Technical Note ◽  
Ductal Adenocarcinoma ◽  
Harmonic Motion ◽  
Hifu Ablation

scholarly journals AFM-based Analysis of Wharton’s Jelly Mesenchymal Stem Cells

2019 ◽  
Vol 20 (18) ◽  
pp. 4351
Author(s):  
Renata Szydlak ◽  
Marcin Majka ◽  
Małgorzata Lekka ◽  
Marta Kot ◽  
Piotr Laidler
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Wharton’S Jelly ◽  
In Vitro Cultivation ◽  
Multipotent Stem Cells ◽  
Wharton's Jelly ◽  
Migration Potential

Wharton’s jelly mesenchymal stem cells (WJ-MSCs) are multipotent stem cells that can be used in regenerative medicine. However, to reach the high therapeutic efficacy of WJ-MSCs, it is necessary to obtain a large amount of MSCs, which requires their extensive in vitro culturing. Numerous studies have shown that in vitro expansion of MSCs can lead to changes in cell behavior; cells lose their ability to proliferate, differentiate and migrate. One of the important measures of cells’ migration potential is their elasticity, determined by atomic force microscopy (AFM) and quantified by Young’s modulus. This work describes the elasticity of WJ-MSCs during in vitro cultivation. To identify the properties that enable transmigration, the deformability of WJ-MSCs that were able to migrate across the endothelial monolayer or Matrigel was analyzed by AFM. We showed that WJ-MSCs displayed differences in deformability during in vitro cultivation. This phenomenon seems to be strongly correlated with the organization of F-actin and reflects the changes characteristic for stem cell maturation. Furthermore, the results confirm the relationship between the deformability of WJ-MSCs and their migration potential and suggest the use of Young’s modulus as one of the measures of competency of MSCs with respect to their possible use in therapy.

scholarly journals Novel Biocompatible Zr-Based Alloy with Low Young’s Modulus and Magnetic Susceptibility for Biomedical Implants

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5130
Author(s):  
Renhao Xue ◽  
Dong Wang ◽  
Dawei Yang ◽  
Ligang Zhang ◽  
Xiaoning Xu ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Young’S Modulus ◽  
Blood Compatibility ◽  
Young's Modulus ◽  
Emission Spectrometry ◽  
Biomedical Implants ◽  
Ion Release ◽  
Mg63 Cells ◽  
Ti Addition

The microstructure, mechanical properties, magnetic susceptibility, electrochemical corrosion performance, in vitro cell compatibility and blood consistency of Zr-16Nb-xTi (x = 0, 4, 8, 12 and 16 wt.%) materials were investigated as potential materials for biomedical implants. X-ray diffraction (XRD) and Transmission electron microscopy (TEM) analyses revealed the secondary phase martensite α’ formed during the quenching process. The phase composition contained metastable β and martensite α’, resulting from Ti addition. These phase constitutions were the main causes of a low Young’s modulus and magnetic susceptibility. The in vitro cytocompatibility analysis illustrated that the MG63 cells maintained high activity (from 91% to 97%) after culturing in Zr-16Nb-xTi extraction media for 12 days due to the high internal biocompatibility of Zr, Nb and Ti elements, as well as the optimal corrosion resistance of Zr-16Nb-xTi. On the basis of Inductively coupled plasma optical emission spectrometry (ICP-OES) ion release studies, the concentration of Zr, Nb and Ti was noted to reach the equipment detective limit of 0.001 mg/L, which was much lower than pure Ti. With respect to the corrosion behavior in Hank’s solution, Zr-16Nb-16Ti displayed superior properties, possessing the lowest corrosion current density and widest passivation region, attributed to the addition of Ti. The blood compatibility test illustrated that the Zr-16Nb-xTi materials were nonhemolytic, and the platelets maintained a spherical shape, with no aggregation or activation on Zr-16Nb-xTi. Overall, Ti addition has obvious effects on the developed Zr-16Nb-xTi alloys, and Zr-16Nb-4Ti exhibited low magnetic susceptibility, low modulus, good biocompatibility and proper corrosion properties, demonstrating the potential of use as implant biomaterials.

Nonisometric behavior of fascicles during isometric contractions of a human muscle

1998 ◽  
Vol 85 (4) ◽  
pp. 1230-1235 ◽  
Author(s):  
Masamitsu Ito ◽  
Yasuo Kawakami ◽  
Yoshiho Ichinose ◽  
Senshi Fukashiro ◽  
Tetsuo Fukunaga
Keyword(s):  
Young’S Modulus ◽  
Joint Angle ◽  
Young's Modulus ◽  
Pennation Angle ◽  
Human Muscle ◽  
Isometric Contractions ◽  
Fascicle Length ◽  
Tendon Stiffness ◽  
Tendon Elongation

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.

Sign in / Sign up

Export Citation Format

Share Document