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Paralaryngeal mass with secondary extension to the thyroid cartilage involving confluent cysts, subjected to conservative surgical treatment with a diagnosis of giant cell tumor of soft tissues, a neoplasm morphologically similar but genetically unrelated to osseous giant cell tumors.

Bioaccumulation of heavy metals in mangrove crabs has been reported and most of them are toxic to animals and potential human carcinogens. Given that the land crab Cardisoma armatum Herklots, 1951 is more consumed by surrounding populations, this study aimed to quantify the levels of metals in its tissues and to assess the human health risks. Soft tissues were isolated in adult crabs and frozen then; samples were dried, crushed and handled following the standard procedures. Human health risks were evaluated using some indices. Heavy metal levels in each tissue were shown in decreasing order: Fe > Zn > Al > Cu > Cd > Pb. Cadmium, lead and copper metals were in upper levels in the hepatopancreas (0.35, 0.19 and 7.88 mg/kg) whereas iron, aluminium and zinc were higher in muscles (129.30, 15.96 and 82.83 mg/kg). Most EDI values were apparently below the PTDI and CRLim values signifying that the consumption of C. armatum remains safe for consumers although, a limit in intake frequency might be required for children. For all metals, THQ and HI values were below the standard value 1 indicating no health risks in consumers due to the intake of single or several metals. Also, the carcinogenic risks for Cd and Pb metals are considered to be negligible because they are lower than 10−6. Overall, regarding the results, consumption of C. armatum seems harmless for human health in the study area.

Studies have primarily simulated the interface pressure and skin surface stress produced by compression textiles or garments with a single pressure level. However, only a few studies have reported the biomechanical transmission behaviors of compression fabrics from the skin to deeper soft tissues of the human body, especially within the context of compression fabrics providing multiple pressure levels. Therefore, to address this limitation, this study developed novel 3D finite element (FE) models to characterize and visualize the interface pressure exerted at the skin surface by elastic compression stockings (ECSs), a type of typical compression textiles, with either low- or high-pressure levels, and to analyze the resulting stress and stress transmission effects within lower limb tissues. The results of the validated FE models indicated that the simulated interface pressure favorably agreed with the measured pressure data. A close relationship existed between the pressure magnitudes and the lower limb surface curvatures, with the highest interface pressure occurring at the anterior and posterior bony regions of the ankle with greater surface curvatures than those of the posterior calf. The internal tissue stress distributions largely varied, which may be one of the potential causes for the inconsistency observed between the claimed pressure doses and those practically delivered inside. Overall, this study serves to improve the understanding of the working mechanisms of the ECS-lower limb system, allowing for improved functional material design and evaluation of the pressure effectiveness of compression textiles and garments used in physiotherapy.

Understanding spinal cord injury requires a comprehensive knowledge of its mechanical properties, which remains debated due to the variability reported. This study aims to characterize the regional mechanical properties of the spinal cord in transverse sections using micro-indentation. Quasi-static indentations were performed on the entire surface of transverse slices obtained from 10 freshly harvested porcine thoracic spinal cords using a 0.5 mm diameter flat punch. No significant difference in average longitudinal elastic modulus was found between white matter (n = 183, E = 0.51 ± 0.21 kPa) and gray matter (n = 51, E = 0.53 ± 0.25 kPa). In the gray matter, the elastic modulus in the dorsal horn (0.48 ± 0.18 kPa) was significantly smaller than in the ventral horn (0.57 ± 0.24 kPa) (GLMM, p < 0.05). The elastic modulus in the dorsal horn was also significantly smaller than in the lateral (0.52 ± 0.22 kPa) and ventral funiculi (0.53 ± 0.18 kPa) of the white matter (GLMM, p < 0.05). However, there was no significant difference in the elastic modulus among the ventral, lateral and dorsal funiculi of the white matter (GLMM, p > 0.05). The average elastic modulus strongly varies between samples, ranging from 0.23 (±0.06) kPa to 0.79 (±0.18) kPa and the testing time postmortem was significantly associated with a decrease in elastic modulus (t = -5.2, p < 0.001). The spinal cord's white matter demonstrated significantly lower elastic modulus compared to published data on brain tissue tested under similar conditions. These findings enhance our comprehension of the mechanical properties of spinal cord white and gray matter, challenging the homogeneity assumption of current models., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Decellularization is one of a promising technique in the field of biomaterials based on the idea of using an acellular construct, here the organ / tissue itself, as a biocompatible and biological construct. In the decellularization process, the main objective is to preserve the structural and functional properties while removing living cells. In the current paper, we describe an electrochemical method for soft tissue decellularization at a specific voltages and time intervals, as well as further DNA, GAG, protein determinations, and histological examinations for the determination of decellularization efficacy. The approach proposed here, is: • Successful decellularization can be achieved by exposing the tissues to fewer chemicals than the traditional methods. • A facile and fast decellularization process long less than a day • An easy decellularization technique that may be applied to soft tissues

Retained soft tissue foreign bodies following injuries are frequently seen in the Emergency and Plastic Surgery practice. The patients with such presentations require a watchful and detailed clinical assessment to overcome the anticipant possibility of missing them. However, the diagnosis based on the clinical evaluation is usually challenging and needs to be supported by imaging modalities that are suboptimal and may fail in identifying some types of foreign bodies. Owing to that, serious complications such as chronic pain, infection, and delayed wound healing can be faced that necessitate a prompt intervention to halt those detrimental consequences. The classical method of removal is a surgical exploration which is not free of risks. It can cause injuries to vital structures such as nerves and tendons if the foreign body is close to them, also it can be affected by the surgeon's experience and the foreign body's characteristics.In light of that, we conducted a single-center study to understand the utility of a novel vacuum-assisted technique for foreign body removal. The technique is noninvasive and facilitates a real-time foreign body extraction using readily available materials. Twenty patients with 23 Foreign Bodies of various kinds, shapes, and sizes were recruited in our study by using a nonprobability convenient sampling method. Results demonstrated the ability of the described technique to extract 22 of them with no noticeable side effects. This study may encourage further trials adopting similar principles to promote the management of retained foreign bodies with fewer complications, and a potential of time and cost-saving.

Intramuscular Myxoma(IM) is a rare benign soft tissue tumor, and its etiology and histology source is still unclear. It is important to understand the pathological components of IM and its corresponding imaging features, as well as performing accurate and careful imaging assessments of IM before surgery. We present a case of a 43-year-old male who presented a lump in his left thigh and gradually enlarged during the past 8 years. The patient underwent CT, MRI, and CTA examined and was later pathologically confirmed as IM. This article will combine the literature，to explore the imaging manifestations and its pathological basis of intramuscular myxoma.

The breast seldom harbors secondary malignant lesions and is rarer for the kidney to be the origin of the metastatic lesion. Keen Imaging analysis, as well as a high index of suspicion, are critical to differentiate a primary tumor from a metastatic lesion.We describe an unusual case of a recurrent RCC presenting as metastatic lesions to the breast and soft tissue of the right thigh in a 51-year-old patient referred to our breast-imaging unit 10 months after therapeutic surgery.An adequate and close follow-up accompanied by a thorough physical exam and appropriate imaging methods is essential to identify these types of cases.

Biomechanical testing of soft tissues forms the backbone in the experimental validation of tissue engineering and for modelling purposes. The standardized testing of soft tissues requires different experimental protocols and fixtures compared to hard tissues or non-biological materials due to their characteristics. Some of the most commonly-used clamping methods for soft tissue testing affect the tissues’ mechanical properties as chemicals are involved to decelerate degradation and autolysis. Moreover, they are unsuitable for standardized and high-throughput testing. Material slippage is also a recurrent unwanted influence on the testing routine with impact on measurement validity. Addressing these issues, this protocol presents a clamping system for simplified testing of biological soft tissues with all necessary components manufactured utilizing 3D printing technology. Templates allow trimming the samples into standardized shapes and sizes while preparation tables facilitate clamping in a fixed distance. The key parts of the system are clamps with a pyramid design, which allow the mounting of biological soft tissues before transferring it into the testing device and minimize material slippage during tensile testing. Flexible holder arms are used to transfer samples from preparation tables into the testing device and simplify positioning. Mechanical testing itself is performed with digital image correlation for precise strain measurements.

In various medical fields, a change of soft tissue stiffness is associated with its physio-pathological evolution. While elastography is extensively employed to assess soft tissue stiffness in vivo, its application requires a complex and expensive technology. The aim of this study is to determine whether an easy-to-use method based on impact analysis can be employed to determine the concentration of agar-based soft tissue mimicking phantoms. Impact analysis was performed on soft tissue mimicking phantoms made of agar gel with a mass concentration ranging from 1% to 5%. An indicator Δt is derived from the temporal variation of the impact force signal between the hammer and a small beam in contact with the sample. The results show a non-linear decrease of Δt as a function of the agar concentration (and thus of the sample stiffness). The value of Δt provides an estimation of the agar concentration with an error of 0.11%. This sensitivity of the impact analysis based method to the agar concentration is of the same order of magnitude than results obtained with elastography techniques. This study opens new paths towards the development of impact analysis for a fast, easy and relatively inexpensive clinical evaluation of soft tissue elastic properties., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Guillaume Haiat reports financial support was provided by European Research Council and by French National Research Agency. Giuseppe Rosi reports financial support was provided by French National Research Agency., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Collagen fibrils are the basic structural building blocks that provide mechanical properties such as stiffness, toughness, and strength to tissues from the nano- to the macroscale. Collagen fibrils are highly hydrated and transient deformation mechanisms contribute to their mechanical behavior. One approach to describe and quantify the apparent viscoelastic behavior of collagen fibrils is to find rheological models and fit the resulting empirical equations to experimental data. In this study, we consider a nonlinear rheological Maxwell model for this purpose. The model was fitted to tensile stress-time data from experiments conducted in a previous study on hydrated and partially dehydrated individual collagen fibrils via AFM. The derivative tensile modulus, estimated from the empirical equation, increased for decreasing hydration of the collagen fibril. The viscosity is only marginally affected by hydration but shows a dependency with strain rate, suggesting thixotropic behavior for low strain rates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: This study investigates the correlation between soft tissue volumetric changes and clinical periodontal parameters for patients suffering from Stage III periodontitis after non-surgical periodontal treatment (NSPT) via intraoral scanning., Methodology: The following study is a case series pilot study involving twenty-eight Stage III Periodontitis patients. All subjects received full-mouth periodontal examination and intra-oral scanning cat baseline and re-evaluation. NSPT with bi-weekly oral hygiene reviews were carried out, and re-evaluation was performed after 10-12 weeks. Baseline scanned data of all subjects would be superimposed with the corresponding scanned data obtained during re-evaluation to ensure the teeth are in the correct alignment. Boolean subtraction would be performed with the 3D scanned data after superimposition and transformation into a 3D solid. The association of baseline clinical parameters and changes after NSPT with soft tissue volumetric changes up to tooth surface level would be evaluated., Results and Conclusion: Mean volumetric reduction after NSPT was 153.45 mm 3  ± 185.30 mm 3 and 124.06 mm 3  ± 124.17 mm 3 for the maxillary and mandibular arch, respectively. A statistically significant correlation was detected between soft tissue volumetric reduction to baseline and post-treatment clinical periodontal parameters. Posterior teeth were found to have the highest reduction in soft tissue volume. According to this pilot study, baseline clinical periodontal parameters (PPD, CAL, BOP) correlate with the soft tissue volumetric reduction after NSPT. Further studies on a larger scale and utilization of digital means on tooth sites would be necessary to strengthen the proof of concept., Clinical Significance: Intraoral scanning can be a valid non-invasive method to assess soft tissue volumetric changes after initial periodontal treatment, which are correlated to changes in the baseline clinical periodontal parameters., Competing Interests: Declaration of Competing Interest No conflict of interest was reported. The authors do not have any financial interests, either directly or indirectly, in the products or information listed in the paper. The authors declare that there are no conflicts of interest in this study. The study was funded by the Periodontal Research Fund of the University of Hong Kong., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Collagen fibrils, which are the lowest level fibrillar unit of organization of collagen, are thus of primary interest towards understanding the mechanical behavior of load-bearing soft tissues. The deformation of collagen fibrils shows unique mechanical features; namely, their high energy dissipation is even superior compared to most engineering materials. Additionally, there are indications that cyclic loading can further improve the toughness of collagen fibrils. Recent experiments from Liu at al. (2018) focused on the response of type I collagen fibrils to uniaxial cyclic loading, revealing some interesting results regarding their rate-dependent and inelastic response. In this work, we aim to develop a model that allows interpreting the complex nonlinear and inelastic response of collagen fibrils under cyclic loading. We propose a constitutive model that accounts for viscoelastic deformations through a decoupled strain-energy density function (into an elastic and a viscous parts), and for plastic deformations through plastic evolution laws. The stress-stretch response results obtained using this constitutive law showed good agreement with experimental data over complex loading paths. Ultimately we use the model to gain more insights on how cyclic loading and rate effects control the interplay between viscoelastic and plastic deformation in collagen fibrils, and to extrapolate the results from experimental data, analyzing how complex cyclic load influences energy dissipation and deformation mechanisms. STATEMENT OF SIGNIFICANCE: In this work, we develop a viscoelastic-plastic constitutive model for collagen fibrils with the aim of analyzing the effects of inelasticity and energy dissipation in this material, and more specifically the competition between viscoelasticity and plasticity in the context of cyclic loading and overload. Experimental and theoretical approaches so far have not fully clarified the interplay between viscous and plastic deformations during cyclic loading of collagen fibrils. Here, we aim to interpret the complex nonlinear response of collagen fibrils and, ultimately, suggest predictive capabilities that can inform tissue-level response and injury. To validate our model, we compare our results against the stress-stretch data obtained from experiments of cyclic loaded single fibrils performed by Liu et al. (2018)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

As far as their mechanical properties are concerned, cancerous lesions can be confused with healthy surrounding tissues in elastography protocols if only the magnitude of moduli is considered. We show that the frequency dependence of the tissue's mechanical properties allows for discriminating the tumor from other tissues, obtaining a good contrast even when healthy and tumor tissues have shear moduli of comparable magnitude. We measured the shear modulus G * (ω) of xenograft subcutaneous tumors developed in mice using breast human cancer cells, compared with that of fat, skin and muscle harvested from the same mice. As the absolute shear modulus |G * (ω)| of tumors increases by 42% (from 5.2 to 7.4 kPa) between 0.25 and 63 Hz, it varies over the same frequency range by 77% (from 0.53 to 0.94 kPa) for the fat, by 103% (from 3.4 to 6.9 kPa) for the skin and by 120% (from 4.4 to 9.7 kPa) for the muscle. These measurements fit well to the fractional model G * (ω)=K(iω) n , yielding a coefficient K and a power-law exponent n for each sample. Tumor, skin and muscle have comparable K parameter values, that of fat being significantly lower; the p-values given by a Mann-Whitney test are above 0.14 when comparing tumor, skin and muscle between themselves, but below 0.001 when comparing fat with tumor, skin or muscle. With regards the n parameter, tumor and fat are comparable, with p-values above 0.43, whereas tumor differs from both skin and muscle, with p-values below 0.001. Tumor tissues thus significantly differs from fat, skin and muscle on account of either the K or the n parameter, i.e. of either the magnitude or the frequency-dependence of the shear modulus., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Anatomical models for research and education are often made of artificial materials that attempt to mimic biological tissues in terms of their mechanical properties. Recent developments in additive manufacturing allow tuning mechanical properties with microstructural designs. We propose a strategy for designing material microstructures to mimic soft tissue viscoelastic behaviour, based on a micromechanical Mori-Tanaka model. The model was applied to predict homogenised viscoelastic properties of materials, exhibiting a matrix-inclusion microstructure with varying inclusion volume fractions. The input properties were thereby obtained from compression relaxation tests on silicone elastomers. Validation of the model was done with experimental results for composite samples. Finally, different combinations of silicones were compared to mechanical properties of soft tissues (hepatic, myocardial, adipose, cervical, and prostate tissue), found in literature, in order to design microstructures for replicating these tissues in terms of viscoelasticity. The viscoelastic Mori-Tanaka model showed good agreement with the corresponding experimental results for low inclusion volume fractions, while high fractions lead to underestimation of the complex modulus by the model. Predictions for the loss tangent were reasonably accurate, even for higher inclusion volume fractions. Based on the model, designs for 3D printed microstructures can be extracted in order to replicate the viscoelastic properties of soft tissues., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Articular degeneration can be characterized by fibrillation and eburnation of the articular layers of the metacarpophalangeal (MP) joint. Structural changes within the articular joint predispose the development of osteophytes, enthesophytes and, in many cases is associated with changes the collateral ligaments of the MP joint. The aim of the present study was to investigate the relationship between degenerative processes of the articular cartilage and the enthesopathies of collateral ligaments (superficial or deep portion) of the equine MP joint, using radiographic, ultrasonographic and anatomopathological exam, as well as establishing their sensitivity. Thirty equine forelimbs were selected from animals that died due to various clinical conditions with an average age of 5.7 years which came from a private clinic or sent to the Laboratory of Veterinary Pathology of UFSM. The specimens were placed in a hydraulic press and submitted to radiographic evaluation of the MP joint (lateromedial, flexed lateromedial, dorsopalmar, dorsolateral-palmaromedial oblique 45 0 and dorsomedial-palmarolateral oblique 45 0 projections). Transversal and longitudinal ultrasound images of the dorsal and collateral aspect of the MP joint were obtained using a Sonosite Edge machine with a 5 to 10 MHz linear transducer. Subsequently, the specimens were sent for gross and histopathological examination. A highly positive correlation (P value <.001) was observed between ultrasonographic and macroscopic techniques, showing a relationship between the cartilaginous degenerations of the MP joint and the medial and lateral LC enthesopathies., (Copyright © 2021. Published by Elsevier Inc.)

The long-term anthropogenic release of mercury (Hg) into the environment has led to contamination of the biosphere, with all forms of Hg showing toxic effects and the ability to accumulate in organisms. Since the 1970s, efforts have been made in Western Europe to reduce Hg emissions and for the economic use of Hg, leading to a reduction in Hg exposure to humans and entire ecosystems. The purpose of this research was to present the total mercury (THg) burden in three mustelids (the piscivorous Eurasian otter and American mink, and the invertebrativorous European badger) inhabiting north-western Poland (mostly floodplains) and other European countries (literature data). Moreover, we wanted to investigate whether reductions in the environmental Hg burden in Europe have resulted in reductions in liver and kidney levels in wild terrestrial mammals (Eurasian otter, wild boar, red deer, roe deer, cervids, leporids, rodents, and ecotrophic groups: piscivorous mustelids, non-mustelids whose diets include aquatic prey, canids and other carnivores, omnivores, herbivores), between samples collected before and after 2000. We revealed significantly higher nephric THg levels in roadkilled than in trapped American minks. As roadkilled piscivorous mustelids from the same floodplain had similar hepatic and nephric THg concentrations, we suggest that the European research on Hg ecotoxicology should more often use alien American mink instead of the protected Eurasian otter. Badgers inhabiting Polish and other European floodplains bioaccumulated higher amounts of THg than those from other areas, and as such, may be recommended as bioindicator of mercury soil contamination. Our analysis of abundant data on mammalian hepatic and nephric THg concentrations (excluding non-piscivores mustelids) showed that in 12 of 21 cases, Hg concentrations had dropped significantly since 2000. This data signals a reduction in Hg contamination in terrestrial mammals, such as the Eurasian otter, and may be reason for cautious optimism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

The effect of the exclusion of the compressed fibers in the identification of material parameters from uniaxial tensile tests on two orthogonal strips is investigated. The micro-structurally based constitutive model with two dispersion parameters developed by Holzapfel and his colleagues is utilized in the study. A new exclusion method, based on the coefficient reflecting the percentage of stretched fibers, is proposed. The material parameters are identified by using experimental data from 30 uniaxial tensile tests (5 donors, 6 strips per donor) and a genetic algorithm code that is capable to find the optimal set of parameters. The contraction of the strip width computed by using the hyperelastic model with the identified material parameters is compared to the experimental data for two human aortas (one from literature and one experiment, specific for this study), in order to show the accuracy of the identified model. The complex behavior of the thickness deformation of the strip is also obtained and compared to the experimental data derived from in-plane measurements and the incompressibility condition. Results show that the in-plane fiber exclusion is appropriate for aortic material characterization with uniaxial tensile tests, reducing very significantly the computational cost. At the same time, thickness growth of strips during uniaxial tests is possible, depending on fiber dispersion and orientation., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The ability to predict patient-specific soft tissue deformations is key for computer-integrated surgery systems and the core enabling technology for a new era of personalized medicine. Element-Free Galerkin (EFG) methods are better suited for solving soft tissue deformation problems than the finite element method (FEM) due to their capability of handling large deformation while also eliminating the necessity of creating a complex predefined mesh. Nevertheless, meshless methods based on EFG formulation, exhibit three major limitations: (i) meshless shape functions using higher order basis cannot always be computed for arbitrarily distributed nodes (irregular node placement is crucial for facilitating automated discretization of complex geometries); (ii) imposition of the Essential Boundary Conditions (EBC) is not straightforward; and, (iii) numerical (Gauss) integration in space is not exact as meshless shape functions are not polynomial. This paper presents a suite of Meshless Total Lagrangian Explicit Dynamics (MTLED) algorithms incorporating a Modified Moving Least Squares (MMLS) method for interpolating scattered data both for visualization and for numerical computations of soft tissue deformation, a novel way of imposing EBC for explicit time integration, and an adaptive numerical integration procedure within the Meshless Total Lagrangian Explicit Dynamics algorithm. The appropriateness and effectiveness of the proposed methods is demonstrated using comparisons with the established non-linear procedures from commercial finite element software ABAQUS and experiments with very large deformations. To demonstrate the translational benefits of MTLED we also present a realistic brain-shift computation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Present study provides a numerical investigation on multiscale boundary conditions in the computational homogenization of a representative volume element (RVE) of tendon fascicles. A three-dimensional hexagonal-helicoidal finite element RVE composed of two material phases (collagen fibers and cells) and three finite strain viscoelastic models (collagen fibrils, matrix of fibers and cells) compose the multiscale model. Due to the unusual helical geometry of the RVE, the performance of four multiscale boundary conditions is evaluated: the linear boundary displacements model, the minimally constrained model and two mixed boundary conditions allying characteristics of both, linear and minimal models. Numerical results concerning microscopic kinematic fields and macroscopic stress-strain curves point out that one of the mixed models is able to predict the expected multiscale mechanics of the RVE, presenting sound agreement with experimental facts reported in literature, for example: characteristic non-linear shape of the stress-strain curves; macroscopic energy loss by hysteresis; axial rotation of fascicles observed in tensile tests; collagen fibrils are the main load-bearing components of tendons; cells contribute neither to the stiffness nor to the macroscopic energy loss. Moreover, the multiscale model provides important insights on the micromechanics of tendon fascicles, predicting a non-homogeneous and relevant strain localization on cells, even under physiological macroscopic strain amplitudes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Biopolymers such as gelatin (Gel) and cellulose nanofibrils (CNF) have many of the essential requirements for being used as scaffolding materials in tissue regeneration; biocompatibility, surface chemistry, ability to generate homogeneous hydrogels and 3D structures with suitable pore size and interconnection, which allows cell colonization and proliferation. The purpose of this study was to investigate whether the mechanical behaviour of the Gel matrix can be improved by means of functionalization with cellulose nanofibrils and proper cross-linking treatments. Blending processes were developed to achieve a polymer nanocomposite incorporating the best features of both biopolymers: biomimicry of the Gel and structural reinforcement by the CNF. The designed 3D structures underline interconnected porosity achieved by freeze-drying process, improved mechanical properties and chemical stability that are tailored by CNF addition and different cross-linking approaches. In vitro evaluations reveal the preservation of the biocompatibility of Gel and its good interaction with cells by promoting cell colonization and proliferation. The results support the addition of cellulose nanofibrils to improve the mechanical behaviour of 3D porous structures suitable as scaffolding for tissue regeneration., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study is to characterize mechanical properties of uniaxial tension and stress relaxation responses of muscle tissues of tongue and soft palate. Uniaxial tension test and stress relaxation test on 39 fresh tissue samples from four five-month-old boars (65 ± 15 kg) are conducted. Firstly, the rationality of the samples' dimension design and experimenal data measurement is validated by one-way ANOVA F-type test. Mechanical properties, including stress-strain relationship and stress relaxation characteristic, are then investigated in details to show the nonlinear behaviors of the tissue samples clearly. Finally, a constitutive model of representing the mechanical properties is formulated within the nonlinear integral representation framework proposed by Pinkin and Rogers, and corresponding material parameters are fitted to the experimental data based on the Levenberg-Marquardt minimization algorithm. The results of the fitting comparison prove that the formulated constitutive model can capture the observed nonlinear behaviors of the muscle tissue samples in both the axial tension and stress relaxation experiments., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

As life expectancy and activity levels of patients increase so does the demand on total knee replacements (TKRs). Abnormal mechanics and wear of TKRs can lead to implant loosening and early failure. Polyethylene inserts of varying design and conformity have been introduced in the past decade to improve stability and patient's confidence in the replaced knee, particularly in cases where soft tissue support around the knee is sub optimal. This study experimentally investigated the effect of variation in the soft tissues on the kinematics and wear of a TKR on three different tibial insert designs. DePuy Sigma fixed bearing TKRs with moderately cross-linked UHMWPE and the ISO force control inputs were used. Different soft tissue constraints were simulated using virtual springs in an ISO force controlled simulation system. The spring gaps and stiffness' were varied and their effect on the output kinematics and wear rates assessed. The lower conformity inserts resulted in significantly higher displacements and more variation between the stations on the simulator. They were also more sensitive to changes in the soft tissue constraints than the high conformity insert. The wear rate for the high tension springs was significantly lower than for the lower tension springs tested. Tibial insert geometry and soft tissue constraints significantly affected kinematics and wear in these experimental simulations. Soft tissue constraints and the variability in patients are important considerations in the stratified design of TKRs and approach to patient selection., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In this study we applied the recently developed "Checklist and Scoring System for the Assessment of Soft Tissue Preservation in Human Mummies" to catacomb mummies from Palermo, Sicily. Data from twenty-three full-body computed tomography (CT) examinations were available. These consisted of seventeen adults and six children dating from the late 18th to the late 19th centuries AD. Seventeen of these mummies were anthropogenically mummified, and six spontaneously. Based on the checklist and scoring system, soft tissue preservation varied between both mummification groups, among mummies with the same type of mummification, and within individual mummies at different anatomical locations. Checkpoints of the main category "A. Soft Tissues of Head and Musculoskeletal System" were clearly more frequent than checkpoints of the main category "B. Organs and Organ Systems". Among the anthropogenic mummies, intra-arterial filling achieved the highest preservation status of organs and organ systems. Despite the small sample size, the statistical evaluation showed significant differences between mummification types, with the highest soft tissue preservation found in anthropogenic mummies. Application of the "Checklist" allowed a standardized assessment and documentation of the soft tissue preservation of these mummies. The "Scoring System" facilitated a comparison among mummification groups and mummies by means of numeric values., (Copyright © 2018 Elsevier Inc. All rights reserved.)

In the domain of soft tissue biomechanics, the development of numerical simulations has raised the experimental challenge of identifying local internal mechanical constitutive data of heterogeneous organs (e.g. brain tissue). In this context, this paper presents an ex-vivo alternative characterization method to full-field imaging techniques. It is based on automated, multiple indentations of an organ section using a custom-built rig, effectively allowing to map the viscoelastic and hyperelastic constitutive parameters of the tissue at the millimetre scale, under dynamic conditions. In this paper, this technique is described and used to map the constitutive data of three sections from porcine liver, kidney and brain tissues. The results of this mapping present strong evidence of correlation between the organ constituents (e.g. white/grey matter distribution) and the identified constitutive parameters. It was also found that brain and kidney tissues are highly heterogeneous in terms of identified properties, suggesting that such a technique is essential for fully characterizing their mechanical behaviour. This method opens the way to 3D mapping of constitutive parameters to feed finite element models of the organs with region-specific properties., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A systematic investigation of the factors affecting the suture retention test is performed. The specimen width w and the distance a of the suture bite from the specimen free edge emerge as the most influential geometrical parameters. A conservative approach for the quantification of suture retention strength is identified, based on the use of a camera to monitor the incipient failure and detect the instant of earliest crack propagation. The corresponding critical force, called break starting strength, is extremely robust against test parameter variations and its dependence on the specimen geometry becomes negligible when a≥ 2mm and w≥ 10mm. Comparison of suture retention and mode I crack opening tests reveals a linear correlation between break starting strength and tearing energy. This suggests that the defect created by the needle and the load applied by the suture thread lead to a fracture mechanics problem, which dominates the initiation of failure., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Many biological materials fail by cracking. Examples are bone fractures, contact damage in eggs, splits in bamboo culm and defects in cartilage. The mechanical property that best describes failure by cracking is fracture toughness, which quantifies the ease with which cracks propagate and defines a material's tolerance for pre-existing cracks and other stress concentrating features. The measurement of fracture toughness presents some challenges, especially for biological materials. To obtain valid results requires care and, in many cases, considerable ingenuity to design an appropriate specimen and test protocol. Common mistakes include incorrect interpretation of the mechanics of loading in unusual specimen designs, and failures occurring at the material's ultimate tensile strength as a result of specimens or cracks being too small. Interpretation of the resulting toughness data may also present challenges, for example when R-curve behaviour is present. In this article, examples of good and bad practice are described, and some recommendations made., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A new procedure for determination of elements derived from titanium implants and physiological elements in soft tissues by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is presented. The analytical procedure was developed which involved preparation of in-house matrix matched solid standards with analyte addition based on certified reference material (CRM) MODAS-4 Cormorant Tissue. Addition of gelatin, serving as a binding agent, essentially improved physical properties of standards. Performance of the analytical method was assayed and validated by calculating parameters like precision, detection limits, trueness and recovery of analyte addition using additional CRM - ERM-BB184 Bovine Muscle. Analyte addition was additionally confirmed by microwave digestion of solid standards and analysis by solution nebulization ICP-MS. The detection limits are in range 1.8μgg -1 to 450μgg -1 for Mn and Ca respectively. The precision values range from 7.3% to 42% for Al and Zn respectively. The estimated recoveries of analyte addition line within scope of 83%-153% for Mn and Cu respectively. Oral mucosa samples taken from patients treated with titanium dental implants were examined using developed analytical method. Standards and tissue samples were cryocut into 30µm thin sections. LA-ICP-MS allowed to obtain two-dimensional maps of distribution of elements in tested samples which revealed high content of Ti and Al derived from implants. Photographs from optical microscope displayed numerous particles with µm size in oral mucosa samples which suggests that they are residues from implantation procedure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

One of the hallmarks of biological soft tissues is their capacity to grow and remodel in response to changes in their environment. Although it is well-accepted that these processes occur at least partly to maintain a mechanical homeostasis, it remains unclear which mechanical constituent(s) determine(s) mechanical homeostasis. In the current study a nondestructive mechanical test and a two-step inverse analysis method were developed and validated to nondestructively estimate the mechanical properties of biological tissue during tissue culture. Nondestructive mechanical testing was achieved by performing an inflation test on tissues that were cultured inside a bioreactor, while the tissue displacement and thickness were nondestructively measured using ultrasound. The material parameters were estimated by an inverse finite element scheme, which was preceded by an analytical estimation step to rapidly obtain an initial estimate that already approximated the final solution. The efficiency and accuracy of the two-step inverse method was demonstrated on virtual experiments of several material types with known parameters. PDMS samples were used to demonstrate the method's feasibility, where it was shown that the proposed method yielded similar results to tensile testing. Finally, the method was applied to estimate the material properties of tissue-engineered constructs. Via this method, the evolution of mechanical properties during tissue growth and remodeling can now be monitored in a well-controlled system. The outcomes can be used to determine various mechanical constituents and to assess their contribution to mechanical homeostasis., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Bioelectric field models of deep brain stimulation (DBS) are commonly utilized in research and industrial applications. However, the wide range of different representations used for the human head in these models may be responsible for substantial variance in the stimulation predictions., Objective: Determine the relative error of ignoring cerebral vasculature and soft-tissue heterogeneity outside of the brain in computational models of DBS., Methods: We used a detailed atlas of the human head, coupled to magnetic resonance imaging data, to construct a range of subthalamic DBS volume conductor models. We incrementally simplified the most detailed base model and quantified changes in the stimulation thresholds for direct activation of corticofugal axons., Results: Ignoring cerebral vasculature altered predictions of stimulation thresholds by <10%, whereas ignoring soft-tissue heterogeneity outside of the brain altered predictions between -44 % and 174%., Conclusions: Heterogeneity in the soft tissues of the head, if unaccounted for, introduces a degree of uncertainty in predicting electrical stimulation of neural elements that is not negligible and thereby warrants consideration in future modeling studies., Competing Interests: Statement CCM is a paid consultant for Boston Scientific Neuromodulation, and is a shareholder in the following companies: Surgical Information Sciences, Inc.; Autonomic Technologies, Inc.; Cardionomic, Inc.; Enspire DBS, Inc.; Neuros Medical, Inc., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Facial traumas are common in children but often unconsidered. Facial injury is responsible of impressive bleeding because of the rich vascularization of the face; this bleeding is often underestimated because of the immediate arterial vasoconstriction that is very strong for children. The blood volume is 80ml/kg for a newborn, with a total of 250ml, reaching 70ml/kg at one year of age. The evaluation must be rigorously performed due to the risk of a sudden decompensation. Regarding the wounds, the primary repair must be performed directly neat or optimal in case of damaged tissues. The rule is to keep maximum of the integrity and to limit debridement. Careful repair often requires general anesthesia, especially in young children, to facilitate a perfect joining of the edges and of the mucocutaneous lines. Losses of substance should be treated by directed cicatrization. Flaps are never performed in children as a first intention for reasons developed below. Given the elasticity of the facial skeleton, fractures require a brutal shock to occur, but the clinical signs can be misleading. For instance, too specific and sometimes ignored, fractures can show weakly symptomatic signs : the fractures of the condylar and the orbital floor, with their respective complication that are temporomandibular bone ankylosis and definitive diplopia. Possible children abuse should be suspected in case of different age lesions and discrepancies between the told story and types of injuries. Once the vital urgency is eliminated, the orbital emergency should be first considered in facial traumas within the ophthalmology specialty because wounds and contusions of the globe are often under-evaluated and threaten the vision. The second emergency is the orbital floor fracture in its 'trapdoor' type, specific to the child. Combined with a motionless eye and uncontrollable vomiting, this is the second true urgency because it involves the prognosis of the oculomotricity and requires emergency surgery. Finally, dental trauma should not be overlooked because of their functional and aesthetic consequences. Primary cicatrization is usually rapid but scars remain inflammatory during a long time. The risk of hypertrophy exists in case of contusions and lacerations associated with wounds but also during puberty and in some locations. Age interfere with the result because growth will either improve or worsen the initial result, depending on the location and mechanism. The secondary specialized and prolonged managing and monitoring is capital on the functional, aesthetic and psychological points of view., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

This paper presents a projection method for deriving membrane models from the corresponding three-dimensional material models. As a particular example the anisotropic Holzapfel-Gasser-Ogden model is considered. The projection procedure is based on the kinematical and constitutive assumptions of a general membrane theory, considering the membrane to be a general two-dimensional manifold. By assuming zero transverse stress, the Lagrange multiplier associated with the incompressibility constraint can be eliminated from the formulation. The resulting nonlinear model is discretized and linearized within the finite element method. Several numerical examples are shown, considering quadratic Lagrange and NURBS finite elements. These show that the proposed model is in very good agreement with analytical solutions and with full 3D finite element computations., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this study, the dynamic and static compressive properties of the whole porcine temporomandibular joint (TMJ) disc were investigated. The aim of the study was to develop a new simple method for the evaluation of joint viscoelasticity, enabling examination of the load-bearing capacity and joint flexibility of the entire disc. For the experiments, a novel testing fixture that reproduces the condylar and fossa surfaces of the TMJ was developed to replicate TMJ disc geometry. Ten porcine discs were used in the experiments. Each disc was dissected from the TMJ and sinusoidal compressive strain was applied to obtain the storage and loss moduli. Static strain control tests were carried out to obtain the relaxation modulus. The result of static and dynamic tests indicated that the whole disc presented viscoelastic behavior under compression. Storage and loss moduli increased with frequency and the relaxation modulus decreased over time. The loss tangent showed less frequency dependence, with values ranging from 0.2 to 0.3, suggesting that the viscous properties of the disc cannot be neglected. These results provide a better understanding of whole disc mechanical compression behavior under realistic TMJ working conditions., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Mechanical characterization of biological tissues and biomaterials at the nano-scale is often performed using nanoindentation experiments. The different constituents of the characterized materials will then appear in the histogram that shows the probability of measuring a certain range of mechanical properties. An objective technique is needed to separate the probability distributions that are mixed together in such a histogram. In this paper, finite mixture models (FMMs) are proposed as a tool capable of performing such types of analysis. Finite Gaussian mixture models assume that the measured probability distribution is a weighted combination of a finite number of Gaussian distributions with separate mean and standard deviation values. Dedicated optimization algorithms are available for fitting such a weighted mixture model to experimental data. Moreover, certain objective criteria are available to determine the optimum number of Gaussian distributions. In this paper, FMMs are used for interpreting the probability distribution functions representing the distributions of the elastic moduli of osteoarthritic human cartilage and co-polymeric microspheres. As for cartilage experiments, FMMs indicate that at least three mixture components are needed for describing the measured histogram. While the mechanical properties of the softer mixture components, often assumed to be associated with Glycosaminoglycans, were found to be more or less constant regardless of whether two or three mixture components were used, those of the second mixture component (i.e. collagen network) considerably changed depending on the number of mixture components. Regarding the co-polymeric microspheres, the optimum number of mixture components estimated by the FMM theory, i.e. 3, nicely matches the number of co-polymeric components used in the structure of the polymer. The computer programs used for the presented analyses are made freely available online for other researchers to use., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Sarcomas constitute 1% of all malignancies, but 10% occur in the head and neck (HN), and they are poorly understood. We present a large series of Soft Tissue HN sarcomas in Mexican patients with survival analysis., Study Design: This is a retrospective study of cases in a cancer hospital., Methods: Review of files and pathology material. Literature review., Results: We analysed 108 patients (55 men / 53 women). The age at presentation was 37 years. The original diagnosis changed in nine cases (8.3%). The most common subtype was rhabdomyosarcoma. Ninety percent of tumours were deep, 91% were high grade, 44% had metastasis, 63% measured >5 cm, overall 5-year survival (5 y-OS) was 48%, and histological high grade was associated with poor survival (p = 0.026)., Conclusion: Sarcomas of the HN are rare. The most affected sites were paranasal sinuses. The majority of tumours were deep, > 5 cm and high grade, 50% had metastasis, the 5 y-OS was 48% and the only independent factor associated with 5 y-OS was histologic grade., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Elastofibroma dorsi is a benign tumor which usually occurs at the inferior angle of the scapula. We retrospectively reviewed 14 cases of elastofibroma dorsi, in nine patients. The patients were hospitalized in the departments of plastic surgery, orthopedic surgery or visceral surgery. Mean age was 67 years. The location of the lesions (bilateral in five patients) was typical, in the thoracoscapular region. Nine lesions were removed surgically, six shoulders were asymptomatic after surgery. Elastofibroma is a rare, slow-growing lesion. It occurs in connective tissue of the infrascapular region of elderly patients. The pathogenesis of the lesion still remains unclear. MRI and computed tomography are useful for assessment of elastofibroma dorsi, and can potentially help avoid the need for unnecessary biopsy and surgery, especially in the asymptomatic patient. It should be surgically removed only in symptomatic patients., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Background: Necrotizing fasciitis (NF) is an infection of the soft tissue, and is fatal if not promptly and aggressively treated. Although it is rare, it is not exceptional; nevertheless, its presentation may be misleading and may delay the diagnosis. We highlight the possible synchronous development of NF in multiple noncontiguous areas., Case Report: A 44-year-old diabetic man with no history of trauma complained of nonspecific lower back pain, which he treated with analgesics and oral antibiotics. Erythema at the left arm appeared, and the general condition worsened. The patient was admitted to the Emergency Department, and NF was diagnosed at the right gluteus and left arm., Conclusion: "Synchronous" multifocality is not an expected presentation of NF, and it complicates the diagnosis and delays treatment, with a potentially negative impact on outcome., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We provide the first account of the shear mechanical properties of porcine pancreas using a rheometer both in linear oscillatory tests and in constant strain-rate tests reaching the non-linear sub-failure regime. Our results show that pancreas has a low and weakly frequency-dependent dynamic modulus and experiences a noticeable strain-hardening beyond 20% strain. In both linear and non-linear regime, the viscoelastic behaviour of porcine pancreas follows a four-parameter bi-power model that has been validated on kidney, liver and spleen. Among the four solid organs of the abdomen, pancreas proves to be the most compliant and the most viscous one., (Copyright © 2013 Elsevier Ltd. All rights reserved.)