Quantifying Active and Passive Stiffness in Plantar Flexor Muscles Following Intermittent Maximal Isometric Contractions Using Shear Wave Elastography.

Objective: This study aimed: (i) to investigate the impact of fatigue, triggered by maximal isometric contraction exercises, on the active and passive stiffness of plantar flexors (PF), and (ii) to examine the relationship between changes in mechanical parameters and neuromuscular alterations after fatigue.

Methods: A healthy cohort (n = 12; age = 27.3 ± 5.

Medical textile implants: hybrid fibrous constructions towards improved performances.

Objectives: One main challenge for textile implants is to limit the foreign body reaction (FBR) and in particular the fibrosis development once the device is implanted. Fibrotic tissue in-growth depends on the fiber size, the pore size, and the organization of the fibrous construction. Basically, non-woven fibrous assemblies present a more favorable interface to biological tissues than do woven structures.

Dataset of Inter and intramuscular variability of stiffness in paretic individuals during prone and standing positions.

Several studies have investigated muscle rigidity using SWE. However, the assessments may not consider the most affected regions within the same muscle tissue nor the intramuscular variability of rigidity between muscles of the same muscle group, e.g.

Quantifying Plantar Flexor Muscles Stiffness During Passive and Active Force Generation Using Shear Wave Elastography in Individuals With Chronic Stroke.

Objectives: This study aims to investigate the mechanical properties of paretic and healthy plantar flexor muscles and assesses the spatial distribution of stiffness between the gastrocnemius medialis (GM) and lateralis (GL) during active force generation.

Methods: Shear wave elastography measurements were conducted on a control group (CNT, n=14; age=59.9±10.

Mechanical properties change of immobilized skeletal muscle in short position measured by shear wave elastography and pure shearing test.

The purpose of this study was to evaluate the effects of immobilization on mechanical properties of skeletal muscle over the time. An in vivo rat model was used to investigate the shear modulus change of the flexor carpi ulnaris (FCU) in a short position. Measurements were performed by shear wave elastography (SWE) to compare contralateral and immobilized cases.

Spatial distribution of stiffness between and within muscles in paretic and healthy individuals during prone and standing positions.

This study investigated the inter- and intramuscular variability of plantar flexors stiffness during prone and standing positions at different muscle lengths in healthy and paretic individuals. To access tissue stiffness, shear wave elastography (SWE) measurements were carried out on two groups: control group (CG; n=14; age 43.9±9.

Regional variation in the mechanical properties of the skeletal muscle.

Regional mechanics of skeletal muscle were investigated from equibiaxial testing in vitro on tissue samples. Samples were collected in three excising zones in transversal direction to the myofibers. Thus, the transverse plane stiffness, likely to be dictated by extracellular matrix collagen (ECM), was studied.

Genome-Wide Screening of Transposable Elements in the Whitefly, (Hemiptera: Aleyrodidae), Revealed Insertions with Potential Insecticide Resistance Implications.

Transposable elements (TEs) are genetically mobile units that move from one site to another within a genome. These units can mediate regulatory changes that can result in massive changes in genes expression. In fact, a precise identification of TEs can allow the detection of the mechanisms involving these elements in gene regulation and genome evolution.

Miniature Inverted-Repeat Transposable Elements (MITEs) in the Two Lepidopteran Genomes of and .

Miniature inverted-repeat transposable elements MITEs are ubiquitous, non-autonomous class II transposable elements. The moths, and , are recognized as the two most serious pest species within the genus. Moreover, these pests have the ability to develop insecticide resistance.

Genome-wide characterization of Mariner-like transposons and their derived MITEs in the Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae).

The whitefly, Bemisia tabaci is a hemipteran pest of vegetable crops vectoring a broad category of viruses. Currently, this insect pest showed a high adaptability and resistance to almost all the chemical compounds commonly used for its control. In many cases, transposable elements (TEs) contributed to the evolution of host genomic plasticity.

[Intravitreal viscoelastic injection for management of combined choroidal and retinal detachments].

Introduction: Combined retinal detachment and choroidal detachment (RDCD) is a serious type of retinal detachment occurring mainly in high myopes, which poses many pre-, intra- and postoperative difficulties that can affect the visual prognosis.

Material And Methods: Personal technique used in 8 patients with RDCD, consisting of intravitreal injection (IVI) of a viscoelastic (VE) device 2 to 3 days prior to vitrectomy.

Results: Reattachment of the choroid in all patients, with return to normal IOP, allowing vitrectomy to be performed under optimal conditions.

Screening of Mobilome Revealed Transposable Element Insertions in Insecticide Resistance Genes.

The cotton bollworm Hübner () is an important pest of many crops that has developed resistance to almost all groups of insecticides used for its management. Insecticide resistance was often related to Transposable Element (TE) insertions near specific genes. In the present study, we deeply retrieve and annotate TEs in the genome using the Pipeline to Retrieve and Annotate Transposable Elements, PiRATE.

Mechanical and microstructural changes of skeletal muscle following immobilization and/or stroke.

Patient management following a stroke currently represents a medical challenge. The presented study investigates the effect of immobilization on skeletal muscles in short positions after a stroke. A rat model was implemented in order to compare four situations within 14 days including control group, immobilization of one forelimb without stroke, stroke without immobilization and stroke with immobilization of the paretic forelimb.

Influence of experimental conditions on visco-hyperelastic properties of skeletal muscle tissue using a Box-Behnken design.

The Mechanical characterization of skeletal muscles is strongly dependent on numerous experimental design factors. Nevertheless, significant knowledge gaps remain on the characterization of muscle mechanics and a large number of experiments should be implemented to test the influence of a large number of factors. In this study, we propose a design of experiment method (DOE) to study the parameter sensitivity while minimizing the number of tests.

Arterial Stiffness Assessment by Shear Wave Elastography and Ultrafast Pulse Wave Imaging: Comparison with Reference Techniques in Normotensives and Hypertensives.

Shear wave elastography and ultrafast imaging of the carotid artery pulse wave were performed in 27 normotensive participants and 29 age- and sex-matched patients with essential hypertension, and compared with reference techniques: carotid-femoral pulse wave velocity (cfPWV) determined via arterial tonometry and carotid stiffness (carPWV) determined via echotracking. Shear wave speed in the carotid anterior (a-SWS) and posterior (p-SWS) walls were assessed throughout the cardiac cycle. Ultrafast PWV was measured in early systole (ufPWV-FW) and in end-systole (dicrotic notch, ufPWV-DN).

Loss of anisotropic properties in abdominal aorta aneurysm obtained from the xenograft rat model.

Background: Cellular treatments using mesenchymal stem cells (MSCs) cultured in 3D conditions constitute a solution to the classical surgery in treating abdominal aortic aneurysm (AAA). The recurrent question is: how this type of biotherapy changes the mechanical behavior of artery?

Methods: Experiments measurements based on xenograft rat model showed that the proposed cellular treatment leads to a decreasing radius and length of the AAA during its growth. An inverse finite element method was used to investigate the mechanical hyperelastic behavior of the AAA in the untreated case compared to the treated one.

Effect of cryopreservation at -80°C on visco-hyperelastic properties of skeletal muscle tissue.

This paper investigated the effect of cryopreservation at -80°C on mechanical visco-hyperelastic properties of skeletal muscle. For that, both tensile and compression relaxation tests were performed on porcine tissues samples in fibre and cross-fibre directions. Material parameters were identified by using first order Ogden's strain energy function coupled with second order Maxwell's model.

Mechanical behavior of the abdominal aortic aneurysm assessed by biaxial tests in the rat xenograft model.

This paper addresses the mechanical biaxial behavior of degraded arteries obtained by the rat xenograft model. For that, a pressure myograph was used to perform extension-inflation tests on abdominal aortic aneurysms (AAAs). Furthermore, residual stresses in the aneurismal wall were assessed by opening angle tests.

Diameter and thickness-related variations in mechanical properties of degraded arterial wall in the rat xenograft model.

The purpose of this study was to evaluate the diameter and thickness-related variations in mechanical properties of degraded arterial wall. To this end, ring tests were performed on 31 samples from the rat xenograft model of abdominal aortic aneurysm (AAA) and failure properties were determined. An inverse finite element method was then employed to identify the material parameters of a hyperelastic and incompressible strain energy function.

Influence of bio-lubricants on the orthodontic friction.

The Friction force of Stainless Steel (SS) and Nickel-Titanium (Ni-Ti) rectangular archwires against stainless steel brackets was investigated. Two types of brackets were used namely: Self-ligating brackets (SLB) and conventional brackets (CB). The friction tests were conducted on an adequate developed device under dry and lubricated conditions.

Influence of viscoelastic properties of an hyaluronic acid-based hydrogel on viability of mesenchymal stem cells.

Background: The present research is involved in the framework of the biotherapy using mesenchymal stem cells (MSCs). Here, MSC encapsulation in a hydrogel based on hyaluronic acid (HA) is investigated to optimize the composition of the biomaterial.

Methods: Several formulations candidates of the hydrogel (9 in total) are postulated as a scaffold for the 3D MSC culture in order to investigate their potential to mimic the in vivo cellular environment.

High frequency amplitude detector for GMI magnetic sensors.

A new concept of a high-frequency amplitude detector and demodulator for Giant-Magneto-Impedance (GMI) sensors is presented. This concept combines a half wave rectifier, with outstanding capabilities and high speed, and a feedback approach that ensures the amplitude detection with easily adjustable gain. The developed detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog multipliers.

Mechanical behavior of abdominal aorta aneurysm in rat model treated by cell therapy using mesenchymal stem cells.

Regenerative medicine to substitute conventional surgery or an endovascular stent constitutes currently a challenge to treat abdominal aneurysm artery (AAA). The present paper addresses the following question: Can a cellular therapy from mesenchymal stem cells reestablish the mechanical properties of damaged abdominal aorta? For that, the xenograft rat model that mimics arterial dilatation due to aneurysmal disease is used to study the effects of the proposed cellular therapy. To investigate the changes in the mechanical behavior of the arterial wall, the artery is assumed to be made of a hyperelastic and incompressible material characterized by a strain energy function fitted to the average data set of uniaxial tests of AAA tissue samples.

Optimized hyaluronic acid-hydrogel design and culture conditions for preservation of mesenchymal stem cell properties.

A novel approach that preserved most mesenchymal stem cell (MSC) characteristics was developed using MSC encapsulation in a hydrogel based on hyaluronic acid (HA). An optimized HA-hydrogel composition, whose characteristics were assessed by scanning electron microscopy and viscoelastic property analyses, as well as the more favorable MSC seeding density, was established. These optimal three-dimensional MSC culture conditions allowed morphological cell remodeling, maintained the expression of stem cell markers over 28 days of culture, and preserved MSC differentiation plasticity.

Stochastic modelling of wall stresses in abdominal aortic aneurysms treated by a gene therapy.

A stochastic mechanical model using the membrane theory was used to simulate the in vivo mechanical behaviour of abdominal aortic aneurysms (AAAs) in order to compute the wall stresses after stabilisation by gene therapy. For that, both length and diameter of AAAs rats were measured during their expansion. Four groups of animals, control and treated by an endovascular gene therapy during 3 or 28 days were included.