2,003 results on '"soft tissues"'
Search Results
202. Extremely late-onset pulmonary metastasis from uterine PEComa
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Andrea Ascione, Guido Martignoni, Giulia d’Amati, Carlo Della Rocca, Paolo Graziano, and Angelina Pernazza
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uterus ,lung neoplasms ,PEComa ,lung ,metastases ,soft tissues ,aged ,female ,humans ,perivascular epithelioid cell neoplasms ,uterine neoplasms ,Pathology and Forensic Medicine - Published
- 2022
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203. DIAGNOSIS AND TREATMENT OF RETAINED WOODEN FOREIGN BODIES IN THE EXTREMITIES USING ULTRASOUND
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BARIŞ POLAT, YUNUS ATICI, TAHSIN GÜRPINAR, AYŞE ESIN POLAT, DOĞAÇ KARAGÜVEN, and İSMET TEOMAN BENLI
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Foreign bodies ,Soft tissues ,Ultrasonography ,Medicine ,Orthopedic surgery ,RD701-811 - Abstract
ABSTRACT Objective This study investigates ultrasonography as an effective tool for localizing and measuring the depth and size of wooden foreign bodies to perform less invasive and easier surgery without the need for any additional radiological techniques. Methods Fifteen patients were operated to remove foreign bodies in the extremities in 2016. The side of the affected extremity, the material, size, and location of the foreign body and time of admission after injury were noted, along with CRP, WBC, and erythrocyte sedimentation rate; length of incision, surgery duration, and complications were evaluated. Results The mean patient age was 39.66 (range: 6 to 68). Of the total, 8 of the foreign bodies were in the plantar surfaces of the feet, 3 were in the cruris, 2 were in the palm of the hand, and 2 were in the fingers. All patients underwent ultrasound evaluation before surgery. The surgeries lasted less than 10 min in 13 (87%) of the cases and from 10 to 20 min in 2 cases. No complications were observed in any of the patients. Conclusion Delayed extraction of foreign bodies can lead to local infections. Ultrasonography can be a reliable option for diagnosing and localizing radiolucent foreign bodies such as wooden objects. Level of Evidence IV; Case series. more...
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- 2018
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204. Giant cell tumor of paralaryngeal soft tissues, extending to the laryngeal cartilage.
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Maia Segundo LB, Mello SMB, Furlan MV, de Rosis Sobrinho A, and Abrahao-Machado LF
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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., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.) more...
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- 2024
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205. Atypical adult non-calcified pilomatricoma
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Masih, S, Sorenson, SM, Gentili, A, and Seeger, LL
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Biomedical and Clinical Sciences ,Clinical Sciences ,Biomedical Imaging ,Aged ,Diagnosis ,Differential ,Hair Diseases ,Humans ,Leg ,Magnetic Resonance Imaging ,Male ,Pilomatrixoma ,Skin Neoplasms ,MRI ,neoplasms ,MRI ,soft tissues ,MRI ,soft tissue neoplasms ,skin ,neoplasms ,MRI ,pilomatricoma ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
We present a rare case of a non-calcified pilomatricoma in a 67-year-old man. This tumor was extremely large in size, and its location, in the lower extremity, was very unusual. The clinical, radiographic, and histopathological features are described in detail. The role of magnetic resonance imaging (MRI) in the diagnosis of this entity is discussed. Definite internal reticulations and septations were observed. A possible explanation for this observation is that the high signal intensity reticulations may represent edematous stroma surrounding basaloid cells. more...
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- 2000
206. Force Training for Position/Force Control of Massage Robots
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Golovin, V., Arkhipov, M., Zhuravlev, V., ceccarelli, marco, Series editor, Rodić, Aleksandar, editor, Pisla, Doina, editor, and Bleuler, Hannes, editor
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- 2014
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207. Distribution, Causes and Prevention of Individual Neoplasms
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Boffetta, Paolo, Boccia, Stefania, La Vecchia, Carlo, Boffetta, Paolo, Boccia, Stefania, and La Vecchia, Carlo
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- 2014
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208. Skin cancer: findings and role of high-resolution ultrasound.
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Catalano, Orlando, Roldán, Fernando Alfageme, Varelli, Carlo, Bard, Robert, Corvino, Antonio, and Wortsman, Ximena
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Currently available high-resolution transducers allow a detailed ultrasound (US) assessment of skin tumors. US complements clinical examination, dermoscopy, and biopsy in the initial differential diagnosis, surgical planning, locoregional staging, and follow-up of patients with skin malignancies. It is important for dermatologists, skin surgeons, and US operators to be aware of the US imaging findings and to recognize the clinical scenarios where imaging is indicated in the management of skin cancer. The purpose of this review article is to address the most common indications for US in skin oncology and to provide a comprehensive guide to the gray-scale and color-Doppler findings in cutaneous malignant tumors. [ABSTRACT FROM AUTHOR] more...
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- 2019
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209. Influence of modified titanium abutment surface on peri-implant soft tissue behaviour: A systematic review of histological findings.
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Pesce, Paolo, Menini, Maria, Tommasato, Grazia, Patini, Romeo, and Canullo, Luigi
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META-analysis ,VASCULAR endothelial growth factors ,TITANIUM ,TISSUE adhesions ,DENTAL abutments - Abstract
Purpose: The purpose of the present systematic review was to investigate at the histological level if a modified titanium surface abutment could affect the behaviour of soft peri-implant tissue (connective tissue adhesion and soft tissue inflammation). Materials and methods: An electronic databases research (MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library) until 24 June 2019 for randomised controlled trials (RCTs), controlled clinical trials and non-randomised studies of interventions (NRSI) was performed. The focused question was: "In healthy patients with at least one titanium healing abutment connected to a dental implant, is the effect of a healing abutment surface modification different from machined titanium at the histological level?" The Cochrane Handbook for Systematic Reviews of Interventions to assess the risk of bias in individual studies was used for RCTs. The Newcastle-Ottawa quality assessment scale was used to evaluate NRSI. Results: In total, 192 records were evaluated for titles and abstracts. Seven studies were included in the review. Five of them reported an enhanced soft tissue adhesion in the modified abutment group without increasing the soft tissue inflammation. One study reported no significant differences among titanium-modified (double acid-etched) and titanium-machined groups. One author demonstrated at the 6-month follow-up period a higher level of inflammation around acid-etched surfaces, with a higher number of T and B lymphocytes and expression of vascular endothelial growth factor. Conclusions: Short-term data (< 6 months) suggested an enhanced connective fibre attachment next to titanium abutments with a modified surface and a similar inflammatory response, in comparison with machined surface titanium abutments. However, modified surfaces may lead to a long-term increased risk of a higher degree of inflammation in the peri-implant tissues. Due to limited available evidence, further long-term studies are needed to confirm these results. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
210. Characterization of bony changes localized to the cervical articular processes in a mixed population of horses.
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Haussler, Kevin K., Pool, Roy R., and Clayton, Hilary M.
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HORSES , *THORACIC vertebrae , *NECK pain , *HORSE breeding , *ANIMAL culture , *MUSCULOSKELETAL system , *TISSUES , *ZYGAPOPHYSEAL joint - Abstract
The objectives of this observational, cross-sectional study were to characterize and establish the prevalence of osseous proliferation of articular surfaces, joint margins and adjacent soft tissue attachments (i.e., joint capsule and deep spinal muscles) in a mixed population of horses of variable ages, sizes, and breeds to better capture the full spectrum of disease affecting the cervical articular processes. Cranial and caudal articular processes of the cervical and first three thoracic vertebrae (C2-T3) from 55 horses without a primary complaint of neck pain were evaluated for the presence and severity of abnormal bony changes. Data were analyzed to compare alterations in joint margin quadrants, paired articular surfaces within a synovial articulation, left-right laterality, and vertebral level distributions and to determine associations with age, wither height and sex. Seventy-two percent of articular processes had bony changes that were considered abnormal. Osteophyte formation was the most common bony change noted. Overall grades of severity included: normal (28%), mild (45%), moderate (22%), and severe (5%). The highest prevalence of mild changes was localized to the C3-C6 vertebral levels; moderate changes to C6-T2; and severe changes to C2-C3 and C6-T2. Most paired articular surfaces and left-right grades of severity were not significantly different. The grade of osseous pathology was positively associated with both age and wither height. A high prevalence and wide variety of abnormal bony changes of varying severity were found in articular processes across all vertebral levels. The clinical significance of the described lesions is unknown, but the findings are expected to enhance the reporting of articular process and periarticular changes noted on advanced diagnostic imaging of the equine cervical and cranial thoracic vertebral regions. [ABSTRACT FROM AUTHOR] more...
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- 2019
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211. Clinical evaluation of General Electric new Swiftscan solution in bone scintigraphy on NaI-camera: A head to head comparison with Siemens Symbia.
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Thibault, F., Bailly, M., Le Rouzic, G., and Metrard, G.
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RADIONUCLIDE imaging , *WHOLE body imaging , *BONE products , *SCINTILLATION cameras , *BODY image , *IMAGE processing - Abstract
Purpose: The General Electric (GE) Swiftscan solution combines a new Low Energy High Resolution and Sensitivity collimator (LEHRS) with image processing (Clarity 2D) and tomographic step and shoot continuous mode. The aim of this study was to compare clinical and physical performances of this new technology in bone scintigraphy. Methods: Physical phantom measurements were performed using GE LEHRS, GE Low Energy High Resolution (LEHR) and Siemens LEHR collimators. These measurements were associated with a prospective clinical study. Sixty-seven patients referred for bone scintigraphy were enrolled from February to July 2018. Each patient underwent two acquisitions consecutively on GE and Siemens gamma camera, using respectively Swiftscan solution and LEHR collimator. Results: On planar acquisitions, maximum sensitivity was 100 cts/MBq for Siemens LEHR. GE SwiftScan LEHRS and GE LEHR maximum sensitivity were respectively 9% and 22% lower. Using Clarity 2D, GE Swiftscan LEHRS spatial resolution was the best with 9.2 mm versus 10.1 mm and 10.6 mm for GE LEHR and Siemens LEHR collimators. In tomographic mode, the sensitivity of GE Swiftscan solution was superior to both LEHR systems (16% and 25% respectively for Siemens and GE). There was no significant difference in spatial resolution. In clinical use, signal was higher on Siemens system and noise was lower on GE Swiftscan solution. Contrast-to-noise ratios were not significantly different between the two systems. There was a significant image quality improvement with GE SwiftScan in planar images and in whole body scan. No significant difference in image quality was observed on SPECT images. Conclusion: New GE SwiftScan collimator design improved sensitivity compared to “classical” GE LEHR collimator without compromising resolution. GE SwiftScan solution enhances planar image quality with a better Clarity 2D resolution recovery and noise treatment. In SPECT mode, GE SwiftScan solution improves volumetric sensitivity without significant impact on image quality, and could lead to time or dose reduction. [ABSTRACT FROM AUTHOR] more...
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- 2019
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212. Long-term effects of functional appliances in treated versus untreated patients with Class II malocclusion: A systematic review and meta-analysis.
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Cacciatore, Giorgio, Ugolini, Alessandro, Sforza, Chiarella, Gbinigie, Oghenekome, and Plüddemann, Annette
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MALOCCLUSION , *META-analysis , *PHYSICAL sciences , *ELECTRONIC information resource searching , *LIFE sciences , *DATABASE searching - Abstract
Objective: To assess the cephalometric skeletal and soft-tissue of functional appliances in treated versus untreated Class II subjects in the long-term (primarily at the end of growth, secondarily at least 3 years after retention). Search methods: Unrestricted electronic search of 24 databases and additional manual searches up to March 2018. Selection criteria: Randomised and non-randomised controlled trials reporting on cephalometric skeletal and soft-tissue measurements of Class II patients (aged 16 years or under) treated with functional appliances, worn alone or in combination with multi-bracket therapy, compared to untreated Class II subjects. Data collection and analysis: Mean differences (MDs) and 95% confidence intervals (95% CIs) were calculated with the random-effects model. Data were analysed at 2 primary time points (above 18 years of age, at the end of growth according to the Cervical Vertebral Maturation method) and a secondary time point (at least 3 years after retention). The risk of bias and quality of evidence were assessed according to the ROBINS tool and GRADE system, respectively. Results: Eight non-randomised studies published in 12 papers were included. Functional appliances produced a significant improvement of the maxillo-mandibular relationship, at almost all time points (Wits appraisal at the end of growth, MD -3.52 mm, 95% CI -5.11 to -1.93, P < 0.0001). The greatest increase in mandibular length was recorded in patients aged 18 years and above (Co-Gn, MD 3.20 mm, 95% CI 1.32 to 5.08, P = 0.0009), although the improvement of the mandibular projection was negligible or not significant. The quality of evidence was ‘very low’ for most of the outcomes at both primary time points. Conclusions: Functional appliances may be effective in correcting skeletal Class II malocclusion in the long-term, however the quality of the evidence was very low and the clinical significance was limited. Systematic review registration: CRD42018092139 [ABSTRACT FROM AUTHOR] more...
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- 2019
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213. Spatial distribution of epibionts on olive ridley sea turtles at Playa Ostional, Costa Rica.
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Robinson, Nathan J., Lazo-Wasem, Emily M., Butler, Brett O., Lazo-Wasem, Eric A., Zardus, John D., and Pinou, Theodora
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OLIVE ridley turtle , *LOGGERHEAD turtle , *SEA turtles - Abstract
There is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative information on the spatial variation of epibiont communities on turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We showed that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace or plastron. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurred in relatively low numbers on olive ridleys and the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles. [ABSTRACT FROM AUTHOR] more...
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- 2019
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214. Design of an ultra-thin steerable probe for percutaneous interventions and preliminary evaluation in a gelatine phantom.
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Scali, Marta, Veldhoven, Paulien A. H., Henselmans, Paul W. J., Dodou, Dimitra, and Breedveld, Paul
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STEEL tubes , *STAINLESS steel , *GELATIN , *PHYSICAL sciences , *NICKEL-titanium alloys , *MATERIALS science - Abstract
Needles with diameter under 1 mm are used in various medical applications to limit the risk of complication and patient discomfort during the procedure. Next to a small diameter, needle steerability is an important property for reaching targets located deep inside the body accurately and precisely. In this paper, we present a 0.5-mm prototype probe which is able to steer in three dimensions (3D) without the need of axial rotation. The prototype consists of three Nitinol wires (each with a diameter of 0.125 mm) with a pre-curved tip. The wires are kept together by a stainless steel tube. Each wire is clamped to a block which translates along a leadscrew, the rotation of the latter being controlled by a wheel connected at the distal end of the leadscrew. The tip bends upon retraction of one or two wires. When pushed through a soft solid structure (e.g., a soft tissue or soft tissue phantom), the probe deflects due to off-axis forces acting on its tip by the surrounding structure. We tested the performance of the prototype into a 10% wt gelatine phantom, in terms of the predictability of the steering direction and the controllability of the final position after steering inside the substrate. The results showed that the probe steered in the direction of the retracted wire and that the final position varied from small deflections from the straight path when the wires were slightly retracted, to sharp curvatures for large wire retraction. The probe could be used in various applications, from cases where only a small correction of the path in one direction is needed to cases where the path to be followed includes obstacles and curves in multiple directions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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215. Viscoelastic properties of the central region of porcine temporomandibular joint disc in shear stress-relaxation.
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Barrientos, Eva, Pelayo, Fernandez, Tanaka, Eiji, Lamela-Rey, María Jesús, and Fernández-Canteli, Alfonso
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TEMPOROMANDIBULAR joint , *MODULUS of rigidity , *EVALUATION methodology , *PTERYGOID muscles - Abstract
In this study, shear relaxation properties of the porcine temporomandibular joint (TMJ) disc are investigated. Previous studies have shown that, in fatigue failure and damage of cartilage and fibrocartilage, shear loads could be one of the biggest contributors to the failure. The aim of the present study is to develop an evaluation method to study shear properties of the disc and to do a mathematical characterization of it. For the experiments, twelve porcine discs were used. Each disc was dissected from the TMJ and, then, static strain control tests were carried out to obtain the shear relaxation modulus for the central region of the discs. From the results, it was found that the disc presents a viscoelastic behavior under shear loads. Relaxation modulus decreased with time. Shear relaxation was 10% of the instantaneous stress, which implies that the viscous properties of the disc cannot be neglected. The present results lead to a better understanding of the discs mechanical behavior under realistic TMJ working conditions. [ABSTRACT FROM AUTHOR] more...
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- 2019
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216. Pelvis and femur shape prediction using principal component analysis for body model on seat comfort assessment. Impact on the prediction of the used palpable anatomical landmarks as predictors.
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Savonnet, Léo, Duprey, Sonia, Van Sint Jan, Serge, and Wang, Xuguang
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MULTIPLE correspondence analysis (Statistics) , *PELVIS , *FEMUR , *HIP joint , *MUSCULOSKELETAL system , *TISSUES , *ELECTION forecasting - Abstract
A personalized pelvis and femur shape is required to build a finite element buttock thigh model when experimentally investigating seating discomfort. The present study estimates the shape of pelvis and femur using a principal component analysis (PCA) based method with a limited number of palpable anatomical landmarks (ALs) as predictors. A leave-one-out experiment was designed using 38 pelvises and femurs from a same sample of adult specimens. As expected, prediction errors decrease with the number of ALs. Using the maximum number of easily palpable ALs (13 for pelvis and 4 for femur), average errors were 5.4 and 4.8 mm respectively for pelvis and femur. Better prediction was obtained when the shapes of pelvis and femur were predicted separately without merging the data of both bones. Results also show that the PCA based method is a good alternative to predict hip and lumbosacral joint centers with an average error of 5.0 and 9.2 mm respectively. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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217. Suite of meshless algorithms for accurate computation of soft tissue deformation for surgical simulation.
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Joldes, Grand, Bourantas, George, Zwick, Benjamin, Chowdhury, Habib, Wittek, Adam, Agrawal, Sudip, Mountris, Konstantinos, Hyde, Damon, Warfield, Simon K., and Miller, Karol
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INTERPOLATION algorithms , *FINITE element method , *NUMERICAL integration , *ALGORITHMS , *INDIVIDUALIZED medicine , *NONLINEAR equations , *COMPUTER-assisted surgery - Abstract
• Meshless algorithms for the computation of soft tissue deformation for surgical simulation. • Element Free Galerkin (EFG) is an effective meshless method for nonlinear problems. • Meshless Total Lagrangian Explicit Dynamics (MTLED) solution method bypass the traditional meshless methods. • Application of a new method of imposing the essential boundary conditions. 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. Image, graphical abstract [ABSTRACT FROM AUTHOR] more...
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- 2019
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218. The value of C-reactive protein as an independent prognostic indicator for disease-specific survival in patients with soft tissue sarcoma: A meta-analysis.
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Wang, Xiaolin, Liu, Song, Zhao, Xiaoli, Fang, Erhu, and Zhao, Xiang
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SARCOMA , *PROGRESSION-free survival , *C-reactive protein , *FIXED effects model , *RANDOM effects model , *BLOOD proteins - Abstract
Backgrounds: Serum C-reactive protein (CRP) level has been shown to be a predictor of survival for multiple cancer types. The aim of this study was to evaluate whether pretreatment serum CRP level could serve as a reliable independent prognostic indicator for survival in patients with soft tissue sarcoma (STS). Methods: A detailed literature search was conducted in Medline, Embase and Cochrane for relevant research publications written in English. Patients’ clinical characteristics, outcomes of disease-specific survival (DSS) and disease/recurrence free survival (DFS/RFS) were extracted. Only the results of multivariate survival analysis were recruited in our analysis. Pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the prognostic role of CRP. This study was registered on PROPERO and the registration number is CRD42018104802. Results: Nine articles containing 1655 patients were identified as eligible studies. The random effects model showed that elevated CRP level was significantly correlated with poor DSS (HR = 2.08; 95% CI: 1.33–3.24; p < 0.001). After excluding the heterogeneous study, the fixed effects model showed that elevated CRP level was firmly correlated with poor DSS (HR = 2.36; 95% CI: 1.84–3.03; p < 0.001). The fixed effects model revealed that elevated CRP level was significantly correlated with poor DFS (HR = 1.78; 95% CI: 1.39–2.30; p < 0.001) among studies have more than 100 samples. Conclusion: The results of this meta-analysis suggest that elevated pretreatment serum CRP level could serve as an independent risk factor for poor DSS and DFS/RFS in STS patents. [ABSTRACT FROM AUTHOR] more...
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- 2019
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219. Patterns of soft tissue and cellular preservation in relation to fossil bone tissue structure and overburden depth at the Standing Rock Hadrosaur Site, Maastrichtian Hell Creek Formation, South Dakota, USA.
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Ullmann, Paul V., Pandya, Suraj H., and Nellermoe, Ron
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Abstract Recovery of soft tissues and cells from fossil bones is becoming increasingly common, with structures morphologically consistent with vertebrate osteocytes, blood vessels, fibrous/collagenous matrix, and potential intravascular contents now recognized from specimens dating back to the Permian. However, it largely remains unclear how bone tissue structure, early diagenetic regimes, and many other taphonomic variables influence or control the preservation potential of soft tissues in vertebrate fossils. To explore the influence of a few of these factors, we tested a suite of fossils from the Standing Rock Hadrosaur Site, a vast Edmontosaurus annectens bonebed in the Maastrichtian Hell Creek Formation of South Dakota, for preservation of cellular and tissue components. Demineralization of bone samples from each specimen yielded abundant microstructures morphologically consistent with vertebrate osteocytes, blood vessels, and collagenous matrix. This includes the first recovery of osteocytes and vessels from a fossil vertebral centrum and ossified tendons. Perhaps surprisingly, no correlation was found between soft tissue/cellular recovery and either bone tissue structure type (cortical vs. cancellous) or overburden depth at the time of discovery. A traditional taphonomic survey of the site, conducted in parallel and reported previously, affords a clear and detailed history of these remains, both pre- and postburial. Cumulative taphonomic evidence indicates the Edmontosaurus individuals died in a mass mortality event and their disarticulated remains were buried rapidly in a shallow floodplain pond during a crevasse splay event. Oxygenated flood waters and/or groundwater oxidized initially sideritic concretions to goethite during early diagenesis, facilitating rapid cementation of portions of the sediment that likely aided stabilization of soft tissues by shielding regions of the bones from prolonged exposure to pore fluids. Our findings support cancellous bone as a viable target for cellular analyses, corroborate previous propositions that iron-rich environments and rapid burial facilitate soft tissue preservation, and provide new details into early diagenetic environments conducive to such preservation. Highlights • Demineralization of Edmontosaurus bones released osteocytes and soft tissues. • First recovery of soft tissue and cellular components from fossil ossified tendons. • Overburden depth at discovery did not influence soft tissue or cellular recovery. • Cellular and soft tissue recovery was not correlated with bone tissue structure. [ABSTRACT FROM AUTHOR] more...
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- 2019
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220. Developmental shape changes in facial morphology: Geometric morphometric analyses based on a prospective, population-based, Chinese cohort in Hong Kong.
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Wen, Yi Feng, Wong, Hai Ming, and McGrath, Colman P.
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GEOMETRIC analysis , *ALLOMETRY , *SPACE trajectories , *SEXUAL dimorphism , *MORPHOLOGY , *GEOMETRIC shapes , *ISOGEOMETRIC analysis - Abstract
Background: Thorough understanding of developmental changes of human facial shape is lacking. The present study aimed to evaluate developmental shape changes of facial morphology based on a prospective, population-representative, Chinese cohort in Hong Kong. Methods: A population-representative sample of Chinese in Hong Kong was followed. Serial facial images of over 260 participants were obtained at age 12, 15, and 18 years. Facial landmarks were digitized and the corresponding coordinates were submitted for Generalized Procrustes Analysis. The resultant Procrustes shape coordinates, which captured shape information encoded by the facial landmarks, were then used for statistical shape analyses. Results: Small but significant developmental changes in mean facial shape were observed (p < 0.0001 for all pairwise comparisons). Significant age-related changes in the magnitude of variance of facial shape were also observed (p < 0.05). Phenotypic growth trajectories representing developmental shape changes were similar in size (p > 0.05) between sexes but differed in direction (p < 0.05) in shape space and trajectory shape (p < 0.05). The magnitude of shape differences between sexes remained constant from 12 to 18 years. Results of frontal facial shape analyses after removing the effect of allometry were similar to results obtained before removal of allometry. For lateral facial configurations, allometric trajectories among the age-by-sex groups were similar in slope (p > 0.05) but varied in directions in the multidimensional shape space. Conclusions: Our findings suggested significant age-related changes in facial shape and provided a dynamic view of developmental changes in sexual dimorphism of facial shape. Allometry contributed minimally to developmental changes in frontal facial shape. In addition, the allometric trajectories for lateral facial configurations were similar in rate of shape change but differed in their directions in shape space. [ABSTRACT FROM AUTHOR] more...
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- 2019
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221. Layer-by-layer ultraviolet assisted extrusion-based (UAE) bioprinting of hydrogel constructs with high aspect ratio for soft tissue engineering applications.
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Zhuang, Pei, Ng, Wei Long, An, Jia, Chua, Chee Kai, and Tan, Lay Poh
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TISSUE engineering , *BIOPRINTING , *GELLAN gum , *STRUCTURAL engineering , *PHYSICAL sciences , *BIOCOMPATIBILITY - Abstract
One of the major challenges in the field of soft tissue engineering using bioprinting is fabricating complex tissue constructs with desired structure integrity and mechanical property. To accomplish such requirements, most of the reported works incorporated reinforcement materials such as poly(ϵ-caprolactone) (PCL) polymer within the 3D bioprinted constructs. Although this approach has made some progress in constructing soft tissue-engineered scaffolds, the mechanical compliance mismatch and long degradation period are not ideal for soft tissue engineering. Herein, we present a facile bioprinting strategy that combines the rapid extrusion-based bioprinting technique with an in-built ultraviolet (UV) curing system to facilitate the layer-by-layer UV curing of bioprinted photo-curable GelMA-based hydrogels to achieve soft yet stable cell-laden constructs with high aspect ratio for soft tissue engineering. GelMA is supplemented with a viscosity enhancer (gellan gum) to improve the bio-ink printability and shape fidelity while maintaining the biocompatibility before crosslinking via a layer-by-layer UV curing process. This approach could eventually fabricate soft tissue constructs with high aspect ratio (length to diameter) of ≥ 5. The effects of UV source on printing resolution and cell viability were also studied. As a proof-of-concept, small building units (3D lattice and tubular constructs) with high aspect ratio are fabricated. Furthermore, we have also demonstrated the ability to perform multi-material printing of tissue constructs with high aspect ratio along both the longitudinal and transverse directions for potential applications in tissue engineering of soft tissues. This layer-by-layer ultraviolet assisted extrusion-based (UAE) Bioprinting may provide a novel strategy to develop soft tissue constructs with desirable structure integrity. [ABSTRACT FROM AUTHOR] more...
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- 2019
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222. FEM analysis in excellent cushion characteristic of ostrich (Struthio camelus) toe pads.
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Zhang, Rui, Ling, Lei, Han, Dianlei, Wang, Haitao, Yu, Guolong, Jiang, Lei, Li, Dong, and Chang, Zhiyong
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OSTRICHES , *ACCELERATION (Mechanics) , *TOES , *SOFT tissue injuries , *FINITE element method , *CUSHIONS - Abstract
African ostrich (Struthio camelus) is the largest and fastest extent bipedal animal. The ostrich mainly relies on the 3rd toe to support the entire body under high-speed motion. The short and severe impact concentrated on the limited area would produce tremendous momentary internal stress and strain, which may contribute to the phalanges disloaction, soft tissue damage and the like. The vibration and excessive negative acceleration caused by the ground reaction force also affect the stability of the touching process. Therefore, ostrich toe pads are required to have excellent cushion characteristics. However, current studies often explains the cushion properties by analyzing the macro-microscopic structure of the pad organism, and there is a paucity of research on its biomechanical behaviour. Consequently, from the perspective of multi-layer structure and biomaterial assembly, this study aims to explain the biomechanical characteristics of the ostrich toe pads by FEM (Finite Element Method) analysis. Based on results, we deem that the ostrich toe pad could absorb energy and reduce vibration effectively. Firstly, the multi-layer structure of the pads make the stress and strain decay from outside to inside. Secondly, the minimal response frequency of the pad is 164.22 Hz, making it effectively avoid resonance phenomenon. Finally, the composite material model has the best performance in decreasing the negative acceleration peak value, the impact force peak value and the maximal equivalent stress value at velocities of 0.669 m/s and 1.339 m/s. These results help to further understand the buffer mechanism of the ostrich toe pad, and also have important inter-species reference value for the pathogenesis of human foot soft tissue injury. [ABSTRACT FROM AUTHOR] more...
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- 2019
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223. Development of a pre-clinical experimental simulation model of the natural porcine knee with appropriate ligamentous constraints.
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Liu, Aiqin, Ingham, Eileen, Fisher, John, and Jennings, Louise M.
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KNEE , *SHEARING force , *SIMULATION methods & models , *LIGAMENTS , *MUSCULOSKELETAL system , *TISSUES - Abstract
A robust and stratified pre-clinical natural knee model, which has the capability to more appropriately simulate the biomechanical environment in vivo, will deliver more efficient and reliable assessment of soft tissue interventions before clinical studies. In order to simulate the biomechanical function of the natural knee without the natural ligaments in place, there is a requirement to develop appropriate spring constraints for the natural knee model. Therefore, this study was to investigate the effect of spring constraints on the function and output of the natural porcine knee model, and determine the spring constraint which most closely replicated the function of the natural ligaments. Two linear compression springs with stiffnesses of 9 N/mm (spring-9) and 20 N/mm (spring-20) were set at different free lengths in the anterior-posterior (A/P) axis in a natural knee simulator. The kinematic (A/P displacement) and tribological properties (shear force) output of the simulator were compared at different spring settings. The most appropriate spring setting was determined by comparing the A/P displacement and shear force output at different spring settings with those of the all ligaments model. Spring-9 with a free length of 4 mm showed the minimal difference (-0.03±0.68 mm) in A/P displacement output and spring-20 with a free length of 5 mm showed the minimal difference (-0.10±0.73 mm) in A/P displacement output compared to the all ligament control. There was no statistical difference between the two minimal differences either in A/P displacement or in shear force (paired t-test, p = 0.58, and p = 0.68 respectively) when both spring settings matched most closely to the A/P kinematics of the intact knee. This indicated that both conditions were appropriate spring constraints settings in the A/P direction for the natural porcine knee model. [ABSTRACT FROM AUTHOR] more...
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- 2019
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224. Types of lasers and its applications in dentistry - A review.
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Shreya, S., Ganapathy, Dhanraj, and Ramanathan, Visalakshi
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LASERS , *DENTAL technology , *DENTISTRY - Abstract
LASER refers to light amplification by stimulated emission of radiation. The public is made aware of this by various media, and the word "laser" has power due to patients lookup for the doctors who offer advanced technology. Dentists and their staffs can successfully integrate the use of lasers into the everyday practice of dentistry. The pride and excitement of being on the cutting edge of dentistry and financial incentives make it more possible than ever to implement the use of lasers. "Clinical competence in any area of dentistry appears to require a combination of education and clinical experience." This article features topics of laser science, tissue interaction, types, and uses of lasers in dentistry that provides the foundation for the many applications of the use of lasers in dentistry. [ABSTRACT FROM AUTHOR] more...
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- 2019
225. Tin-filtered 100 kV ultra-low-dose CT of the paranasal sinus: Initial clinical results.
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Petritsch, Bernhard, Kosmala, Aleksander, Weng, Andreas Max, and Bley, Thorsten Alexander
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PARANASAL sinuses , *VITREOUS body , *LIKERT scale , *DIAGNOSTIC examinations , *DIAGNOSTIC imaging , *COMPUTED tomography - Abstract
Objectives: To investigate the feasibility, diagnostic image quality and radiation dose of 3rd generation dual-source computed tomography (CT) using a tin-filtered 100 kV protocol in patients with suspected acute inflammatory sinus disease. Methods: We retrospectively evaluated 109 consecutive patients who underwent CT (Siemens SOMATOM Force, Erlangen, Germany) of the paranasal sinus with a new tin-filtered scan-protocol (Sn100 kV; tube current 35 mAs) using iterative reconstruction. Two readers independently assessed subjective image quality using a five-point Likert scale (1 = excellent, 5 = non-diagnostic). Inter-observer agreement was calculated and expressed as percentage of agreement. Noise was determined for calculation of signal-to-noise-ratio (SNR). Effective radiation dose (ED) was calculated from the dose-length-product (DLP). Results: All examinations showed diagnostic image quality regarding evaluation of inflammatory sinus disease. On average, subjective general image quality was rated moderate (= 3) with a percentage of agreement between the observers of 81%. The mean image noise was 14.3 HU. The calculated median SNR was 6.0 for intraorbital fat, and 3.6 for the vitreous body, respectively. The median DLP was 2.1 mGy*cm, resulting in a median ED of 0.012 mSv. Conclusions: Taking the study limitations into account, ultra-low-dose tin-filtered CT of the paranasal sinus at a tube voltage of 100 kV utilizing an iterative reconstruction algorithm provides for reliable exclusion of suspected acute inflammatory sinus disease in 100% of the cases. [ABSTRACT FROM AUTHOR] more...
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- 2019
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226. A variational homogenization approach applied to the multiscale analysis of the viscoelastic behavior of tendon fascicles.
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Carniel, Thiago André and Fancello, Eduardo Alberto
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COMPOSITE materials , *TENDONS , *POISSON'S ratio , *ATOMIC force microscopy , *AXIAL loads - Abstract
This work presents a variational homogenization approach based on representative volume elements (RVE) in order to investigate the macro- and microviscoelastic behavior of tendon fascicles. A three-dimensional hexagonal–helicoidal finite element RVE is proposed to properly account for the morphology of tendon fascicles observed in serial block-face scanning electron microscopy. Two material phases (collagen fibers and cells) comprising three finite strain variational viscoelastic models (fibrils, matrix of fibers and cells) compose the proposed multiscale model. The material parameters of the micromechanical models were identified with the aid of atomic force microscopy experiments extracted from the literature. A set of multiscale simulations of tensile tests under physiological strain amplitudes were performed, providing the following results. Firstly, numerical predictions corroborate experimental findings: collagen fibrils are the main load-bearing structures of tendons; the cellular matrix contributes neither to the stiffness nor to the energy dissipation of tendons. Secondly, the model brings insights about microscale mechanics of tendon fascicles not completely understood: prediction of uncoiling of fibers during axial loads which may explain the large apparent Poisson ratios and fluid loss, and significant strain localization in cells, which may lead to important mechanotransduction mechanisms. Moreover, the distribution of dissipated power became available, pointing out the fibrils as the main source of dissipation of fascicles under high macroscopic strain rates and during the unloading phase in cyclic regimes. [ABSTRACT FROM AUTHOR] more...
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- 2019
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227. Pediatric non-rhabdomyosarcoma soft tissue sarcoma: heterogeneous group of rare tumors treated with a multidisciplinary approach.
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Beltrami, Giovanni, Ristori, Gabriele, Tamburini, Angela, Lazzarini, Francesco, Scoccianti, Guido, Muratori, Francesco, Franchi, Alessandro, Palomba, Annarita, Roselli, Giuliana, Greto, Daniela, Mangoni, Monica, Capanna, Rodolfo, and Campanacci, Domenico Andrea more...
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SARCOMA , *RADIOISOTOPE brachytherapy , *TUMORS , *LIFE expectancy - Abstract
The so-called non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) account a very heterogeneous group of tumors. The rarity of each histotype prevents the performance of clinical trials on a single tumor type, and consequently, they have to be analyzed as a group. As definitive evidences about treatment are lacking, the aim of the study is to evaluate the prognosis of NRSTS after a multidisciplinary approach, and to test clinical outcomes of surgical reconstructions. It is performed a retrospective analysis of 33 consecutive pediatric-age patients affected by NRSTS seen at a single institution over a 15-year period. Patients were treated using the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) protocol, where surgery plays the main role and chemo- and radiotherapy are variable associated on the basis of the subtype of tumor, yet leaving wide gaps. Thirty-nine percent of patients received only surgical treatment, 33% patients received chemotherapy associated to surgery, only 3% had radiotherapy and surgery and the residual 24% underwent both chemo- and radiotherapy associated to surgery. The overall survival of our series was 91% at 1 year, 86% at 5 years, 81% at 10 years. The local free recurrence survival was 93% at 1 year, 85% at 5 years and 10 years. The metastasis free survival was 78% at 1 year, 75% at 5 years and 10 years. Limb-salvage surgery was possible in the majority of cases (97%) and functional outcomes were generally good, with only a 15% of patients complaining functional deficit. The results are generally satisfactory and in line with the poor literature available; they underline the primary importance of surgery and a multidisciplinary approach. Moreover, reconstructive procedures and functional outcomes must not be left out because life expectancy in these patients is steadily increasing. [ABSTRACT FROM AUTHOR] more...
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- 2019
228. Are Magnetic Resonance Imaging Technologies Crucial to Our Understanding of Spinal Conditions?
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CRAWFORD, REBECCA J., FORTIN, MARYSE, WEBER, KENNETH A., SMITH, ANDREW, and ELLIOTT, JAMES M.
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* SYNOPSIS Persistent spinal (traumatic and nontraumatic) pain is common and contributes to high societal and personal costs globally. There is an acknowledged urgency for new and interdisciplinary approaches to the condition, and soft tissues, including skeletal muscles, the spinal cord, and the brain, are rightly receiving increased attention as important biological contributors. In reaction to the recent suspicion and questioned value of imaging-based findings, this paper serves to recognize the promise that the technological evolution of imaging techniques, and particularly magnetic resonance imaging, is allowing in characterizing previously less visible morphology. We emphasize the value of quantification and data analysis of several contributors in the biopsychosocial model for understanding spinal pain. Further, we highlight emerging evidence regarding the pathobiology of changes to muscle composition (eg, atrophy, fatty infiltration), as well as advancements in neuroimaging and musculoskeletal imaging techniques (eg, fat-water imaging, functional magnetic resonance imaging, diffusion imaging, magnetization transfer imaging) for these important soft tissues. These noninvasive and objective data sources may complement known prognostic factors of poor recovery, patient self-report, diagnostic tests, and the "-omics" fields. When combined, advanced "big-data" analyses may assist in identifying associations previously not considered. Our clinical commentary is supported by empirical findings that may orient future efforts toward collaborative conversation, hypothesis generation, interdisciplinary research, and translation across a number of health fields. Our emphasis is that magnetic resonance imaging technologies and research are crucial to the advancement of our understanding of the complexities of spinal conditions. [ABSTRACT FROM AUTHOR] more...
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- 2019
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229. A multi-GPU accelerated virtual-reality interaction simulation framework.
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Shao, Xuqiang, Xu, Weifeng, Lin, Lina, and Zhang, Fengquan
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GRAPHICS processing units , *ERGONOMICS , *ELASTIC deformation , *PHYSICAL sciences , *VIRTUAL reality , *LIFE sciences - Abstract
In this paper, we put forward a real-time multiple GPUs (multi-GPU) accelerated virtual-reality interaction simulation framework where the reconstructed objects from camera images interact with virtual deformable objects. Firstly, based on an extended voxel-based visual hull (VbVH) algorithm, we design an image-based 3D reconstruction platform for real objects. Then, an improved hybrid deformation model, which couples the geometry constrained fast lattice shape matching method (FLSM) and total Lagrangian explicit dynamics (TLED) algorithm, is proposed to achieve efficient and stable simulation of the virtual objects’ elastic deformations. Finally, one-way virtual-reality interactions including soft tissues’ virtual cutting with bleeding effects are successfully simulated. Moreover, with the purpose of significantly improving the computational efficiency of each time step, we propose an entire multi-GPU implementation method of the framework using compute unified device architecture (CUDA). The experiment results demonstrate that our multi-GPU accelerated virtual-reality interaction framework achieves real-time performance under the moderate calculation scale, which is a new effective 3D interaction technique for virtual reality applications. [ABSTRACT FROM AUTHOR] more...
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- 2019
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230. Design and basic research on accuracy of a novel individualized three-dimensional printed navigation template in atlantoaxial pedicle screw placement.
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Chen, Xiao-Long, Xie, Ya-Fen, Li, Jian-Xin, Wu, Wu, Li, Guan-Nan, Hu, Hui-Jing, Wang, Xiao-Yun, Meng, Zhao-Jian, Wen, Yue-Feng, and Huang, Wen-Hua
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THREE-dimensional printing , *DESIGN research , *SCREWS , *3-D printers , *DESIGN templates , *COMPUTER software - Abstract
Objective: To design and evaluate the accuracy of a novel navigation template suitable for posterior cervical screw placement surgery by using 3D printing technology to improve the existing guiding template design. Methods: The researchers (including spine surgeons and technicians) used CT to perform thin-slice scanning on 12 cases of normal upper cervical vertebral specimens and defined the screw channels that were completely located in the pedicle without penetrating the cortex as ideal screw channels, then designed the ideal channel of the upper cervical vertebral (atlantoaxial) pedicle screw by computer software which was regarded as the preset values, and recorded the screw entrance point, transverse angle and sagittal angle of the ideal channel. Then, researchers designed the novel navigation templates for placement pedicle screw according to the ideal screw channel preset values and manufactured them with one for every single vertebra by 3D printer. A senior spine surgeon performed the posterior surgery to implant pedicle screw on the specimens by the novel navigation templates, then performed CT thin-slice scanning on the specimens again after removing the screws, and reconstructed the actual screws channel by computer software, recorded the screw entrance point, transverse angle and sagittal angle of the actual channels which were defined as the actual values and evaluated them according to Kawaguchi’s pedicle screw evaluation standard finally. The differences between the preoperative preset values of ideal screw channel and the postoperative actual values of actual screw channel were compared by a nonparametric paired rank test. Results: 48 screws were placed on 12 cases of upper cervical vertebral specimens in total. It showed that the grade 0, I, II, III channels in this study were 47, 1, 0, 0, respectively. The grade 0 channels accounted for 97.92% of the total number of channels. There was no significant difference with regard to the screw entrance point, the transverse angle, and the sagittal angle between the preoperative preset values of ideal screw channels and the postoperative actual values of actual screw channels. Conclusion: To implant pedicle screw assisted with the novel individually navigation template designed by 3D printed in the posterior cervical surgery can improve accuracy of pedicle screw placement and safety of the surgery. [ABSTRACT FROM AUTHOR] more...
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- 2019
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231. Photoacoustic elastography imaging: a review.
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Singh, Mayanglambam Suheshkumar and Thomas, Anjali
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ACOUSTIC imaging , *PHOTOACOUSTIC spectroscopy , *TISSUE mechanics , *COHERENCE (Optics) , *PHOTOACOUSTIC effect , *ELASTICITY , *TISSUES - Abstract
Elastography imaging is a promising tool--in both research and clinical settings--for diagnosis, staging, and therapeutic treatments of various life-threatening diseases (including brain tumors, breast cancers, prostate cancers, and Alzheimer's disease). Large variation in the physical (elastic) properties of tissue, from normal to diseased stages, enables highly sensitive characterization of pathophysiological states of the diseases. On the other hand, over the last decade or so, photoacoustic (PA) imaging--an imaging modality that combines the advantageous features of two separate imaging modalities, i.e., high spatial resolution and high contrast obtainable, respectively, from ultrasound- and optical-based modalities--has been emerging and widely studied. Recently, recovery of elastic properties of soft biological tissues--in addition to prior reported recovery of vital tissue physiological information (Hb, HbO2, SO, and total Hb), noninvasively and nondestructively, with unprecedented spatial resolution (μm) at penetration depth (cm)--has been reported. Studies demonstrating that combined recovery of mechanical tissue properties and physiological information--by a single (PA) imaging unit--pave a promising platform in clinical diagnosis and therapeutic treatments. We offer a comprehensive review of PA imaging technology, focusing on recent advances in relation to elastography. Our review draws out technological challenges pertaining to PA elastography (PAE) imaging, and viable approaches. Currently, PAE imaging is in the nurture stage of its development, where the technology is limited to qualitative study. The prevailing challenges (specifically, quantitative measurements) may be addressed in a similar way by which ultrasound elastography and optical coherence elastography were accredited for quantitative measurements. [ABSTRACT FROM AUTHOR] more...
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- 2019
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232. Paradigm shift in geriatric fracture treatment.
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Rommens, Pol Maria
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PREVENTION of surgical complications ,RISK of prosthesis complications ,ELDER care ,ENDOSCOPIC surgery ,FRACTURE fixation ,BONE fractures ,HEALTH status indicators ,OSTEOPOROSIS ,PARADIGMS (Social sciences) ,SOFT tissue injuries ,COMORBIDITY ,BONE density ,OLD age - Abstract
The number of geriatric patients is increasing. These patients exhibit specific characteristics, which influence the type of fracture care. Many patients have comorbidities, which make them more vulnerable to surgical procedures. The soft tissue envelope around the fracture often is compromised due to pre-existing diseases such as diabetes, chronic venous insufficiency or peripheral vascular disease. Bone mineral density has decreased, which enhances the risk of implant loosening. The goals of treatment differ from those, which are valid for younger adults. Primary goal is preserving independency of the elderly patient in his activities of daily life. Advantages and drawbacks of surgical procedures have to be balanced with those of conservative treatment. Fractures of the lower extremities will more often need surgical treatment than fractures of the upper extremities. Patient´s autonomy is best obtained by creating high stability in the fracture plane, which enables motion and weight-bearing. Second priority is prevention of general and local post-operative complications by the use of less invasive surgical procedures. Restoring anatomy and optimal function are less important goals. The implants, which are used, are inserted through small incisions, placed deep under the skin and use long anatomic or osseous corridors. Intramedullary devices have important advantages. This paradigm shift takes the special challenges and requirements of geriatric patients into account. [ABSTRACT FROM AUTHOR] more...
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- 2019
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233. Impact of improved attenuation correction on 18F-FDG PET/MR hybrid imaging of the heart.
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Lindemann, Maike E., Nensa, Felix, and Quick, Harald H.
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POSITRON emission tomography , *CARDIAC imaging , *MAGNETIC resonance imaging , *ACROMIOCLAVICULAR joint , *MAGNETIC resonance , *PETS , *REGIONAL differences - Abstract
Purpose: The aim of this study was to evaluate and quantify the effect of improved attenuation correction (AC) including bone segmentation and truncation correction on 18F-Fluordesoxyglucose cardiac positron emission tomography/magnetic resonance (PET/MR) imaging. Methods: PET data of 32 cardiac PET/MR datasets were reconstructed with three different AC-maps (1. Dixon-VIBE only, 2. HUGE truncation correction and bone segmentation, 3. MLAA). The Dixon-VIBE AC-maps served as reference of reconstructed PET data. 17-segment short-axis polar plots of the left ventricle were analyzed regarding the impact of each of the three AC methods on PET quantification in cardiac PET/MR imaging. Non-AC PET images were segmented to specify the amount of truncation in the Dixon-VIBE AC-map serving as a reference. All AC-maps were evaluated for artifacts. Results: Using HUGE + bone AC results in a homogeneous gain of ca. 6% and for MLAA 8% of PET signal distribution across the myocardium of the left ventricle over all patients compared to Dixon-VIBE AC only. Maximal relative differences up to 18% were observed in segment 17 (apex). The body volume truncation of -12.7 ± 7.1% compared to the segmented non-AC PET images using the Dixon-VIBE AC method was reduced to -1.9 ± 3.9% using HUGE and 7.8 ± 8.3% using MLAA. In each patient, a systematic overestimation in AC-map volume was observed when applying MLAA. Quantitative impact of artifacts showed regional differences up to 6% within single segments of the myocardium. Conclusions: Improved AC including bone segmentation and truncation correction in cardiac PET/MR imaging is important to ensure best possible diagnostic quality and PET quantification. The results exhibited an overestimation of AC-map volume using MLAA, while HUGE resulted in a more realistic body contouring. Incorporation of bone segmentation into the Dixon-VIBE AC-map resulted in homogeneous gain in PET signal distribution across the myocardium. The majority of observed AC-map artifacts did not significantly affect the quantitative assessment of the myocardium. [ABSTRACT FROM AUTHOR] more...
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- 2019
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234. Effects of realistic sheep elbow kinematics in inverse dynamic simulation.
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Poncery, Baptiste, Arroyave-Tobón, Santiago, Picault, Elia, and Linares, Jean-Marc
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ELBOW , *SHEEP , *MAMMAL kinematics , *HUMERUS , *RADIAL bone , *ULNA , *FORELIMB , *DYNAMIC simulation - Abstract
Looking for new opportunities in mechanical design, we are interested in studying the kinematic behaviour of biological joints. The real kinematic behaviour of the elbow of quadruped animals (which is submitted to high mechanical stresses in comparison with bipeds) remains unexplored. The sheep elbow joint was chosen because of its similarity with a revolute joint. The main objective of this study is to estimate the effects of elbow simplifications on the prediction of joint reaction forces in inverse dynamic simulations. Rigid motions between humerus and radius-ulna were registered during full flexion-extension gestures on five cadaveric specimens. The experiments were initially conducted with fresh specimens with ligaments and repeated after removal of all soft tissue, including cartilage. A digital image correlation system was used for tracking optical markers fixed on the bones. The geometry of the specimens was digitized using a 3D optical scanner. Then, the instantaneous helical axis of the joint was computed for each acquisition time. Finally, an OpenSim musculoskeletal model of the sheep forelimb was used to quantify effects of elbow joint approximations on the prediction of joint reaction forces. The motion analysis showed that only the medial-lateral translation is sufficiently large regarding the measuring uncertainty of the experiments. This translation assimilates the sheep elbow to a screw joint instead of a revolute joint. In comparison with fresh specimens, the experiments conducted with dry bone specimens (bones without soft tissue) provided different kinematic behaviour. From the results of our inverse dynamic simulations, it was noticed that the inclusion of the medial-lateral translation to the model made up with the mean flexion axis does not affect the predicted joint reaction forces. A geometrical difference between the axis of the best fitting cylinder and the mean flexion axis (derived from the motion analysis) of fresh specimens was highlighted. This geometrical difference impacts slightly the prediction of joint reactions. [ABSTRACT FROM AUTHOR] more...
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- 2019
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235. Risonanza magnetica in fisioterapia: fondamenti e peculiarità.
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Branchini, Mauro and Branchini, Mirco
- Abstract
Magnetic resonance imaging (MRI) is an imaging technique that uses high-frequency wave magnetic fields. Discovered in 1980, it is mainly used for the study of soft tissues, such as brain structures and spinal cord, abdominal parenchymatous organs and the musculoskeletal system. It is a multi-planar investigation technique that acquires images directly on the axial, coronal or frontal plane. The images obtained are a function of the structure and of the molecules that make up the different organs and body systems, with an extremely high contrast resolution that makes it possible to differentiate, in the context of soft tissues, structurally different anatomical formations, such as muscle, tendon, cartilage, effusion and adipose tissue. [ABSTRACT FROM AUTHOR] more...
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- 2019
236. On multiscale boundary conditions in the computational homogenization of an RVE of tendon fascicles.
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Carniel, Thiago André, Klahr, Bruno, and Fancello, Eduardo Alberto
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BOUNDARY value problems ,ASYMPTOTIC homogenization ,STRESS-strain curves ,HYSTERESIS ,TENSILE tests - Abstract
Abstract 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. Highlights • Multiscale approach for the finite strain analysis of tendon fascicles. • Unusual helical representative volume element (RVE) of a tendon fascicle. • Mixed multiscale boundary condition provides the best representation of RVE deformation. • Strain localization in cells with amplification factor of 10 with respect to macroscopic strains. [ABSTRACT FROM AUTHOR] more...
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- 2019
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237. The effect of consecutive pregnancies on the ovine pelvic soft tissues: Link between biomechanical and histological components.
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Rynkevic, Rita, Martins, Pedro, Andre, Antonio, Parente, Marco, Mascarenhas, Teresa, Almeida, Henrique, and Fernandes, Antonio A.
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PELVIC floor ,PREMATURE ejaculation ,TISSUE mechanics ,SMOOTH muscle ,PELVIC organ prolapse ,TISSUES ,STRESS-strain curves - Abstract
Abstract Background Pelvic organ prolapse, various types of incontinence (urinary incontinence, defecatory dysfunction), chronic cystourethritis, and sexual dysfunctions remain between the most common disorders in urogynecology. Currently, it is believed that the nature and number of births plays a major role in their development. Moreover, after these events, pelvic floor tissues may not recover to their original statuses. The close anatomical relationship among the vaginal wall, bladder and rectum often contribute to the emergence of anatomical-functional failure of adjacent organs and systems. Basic procedures The aim of this study was to investigate the effect of consecutive pregnancies on pelvic floor soft tissues, conducting biomechanical and histological analysis. Fifteen Swifter ewes: virgins, parous and pregnant were used. Samples, for uniaxial tension tests and histological analysis, were cut out from fresh tissue. A description of the mechanical properties of native tissue was obtained from the stress-strain curve. Histological samples were stained with Miller's Elastica staining and analyzed using ImageJ software. Collagen, elastin, and smooth muscle contents (%) were analyzed along the full wall thickness of the selected organs. The links between mechanical properties of the soft tissues and histological parameters were analyzed. Main findings Mechanically, vaginal wall tissue and cervix of pregnant sheep were more compliant. In contrast, bladder and rectum became stiffer and had the highest total collagen content. Parous sheep rectum and bladder were stiffer, compared to virgin sheep. Principal conclusions Tensile strength appears to be linked to total collagen content. Elastin and smooth muscle show a direct influence on tissue compliance. [ABSTRACT FROM AUTHOR] more...
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- 2019
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238. Prediction of difficult tracheal intubations in thyroid surgery. Predictive value of neck circumference to thyromental distance ratio.
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De Cassai, Alessandro, Papaccio, Francesco, Betteto, Giorgia, Schiavolin, Chiara, Iacobone, Maurizio, and Carron, Michele
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TRACHEA intubation , *THYROID gland surgery , *NECK anatomy , *BODY mass index , *BODY weight - Abstract
Introduction: Difficult tracheal intubation (DTI) contributes to perioperative morbidity and mortality. There are conflicting study results about the most predictive DTI risk criteria in patients undergoing thyroid surgery. Materials and methods: We conducted a prospective observational study on 500 consecutive patients aged ≥18 years to identify predictors for DTI. Body weight, body mass index (BMI), inability to prognath, head movement, mouth opening, Mallampati score, neck circumference (NC), thyromental distance (TMD), neck circumference to thyromental distance ratio (NC/TMD), tracheal deviation apparent on chest x-ray, mediastinal goiter, histology and history of DTI were measured as possible predictors of DTI. Spearman's rank correlation test and multiple logistic regression analysis were performed. Results: DTI was observed in 9.6% of all patients. Compared with the group of patients without DTI, the group of patients with DTI had significantly greater median values for body weight, BMI, NC, NC/TMD, Mallampati score, el-Ganzouri score, incidence of mediastinal goiter, and had reduced TMD and mouth opening. Significant correlations between BMI ≥30 kg/m2 and the Mallampati score ≥3 (R = 0.124, p = 0.00541), Cormack-Lehane ≥3 (R = 0.128, p = 0.00409), NC ≥40 cm (R = 0.376, p<0.001), and NC/TMD ≥5 (R = 0.103, p = 0.0207) were found. The logistic regression analysis revealed that an NC ≥40 cm at the goiter level, but not an NC/TMD ratio ≥5, was the strongest predictor of DTI (p<0.001). The area under the receiver operating characteristic curve for NC/TMD was better than the curve for NC. The sensitivity and specificity of NC/TMD were also greater, compared with NC. An NC of 40.00 cm and an NC/TMD of 5.85 were the estimated cut-off points. Discussion: This study found that NC was a strong predictor of DTI. The results also suggested that NC/TMD could be used as a measure to stratify the risk of DTI in patients undergoing thyroid surgery. [ABSTRACT FROM AUTHOR] more...
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- 2019
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239. Machine learning analysis of gene expression data reveals novel diagnostic and prognostic biomarkers and identifies therapeutic targets for soft tissue sarcomas.
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van IJzendoorn, David G. P., Szuhai, Karoly, Briaire-de Bruijn, Inge H., Kostine, Marie, Kuijjer, Marieke L., and Bovée, Judith V. M. G.
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MACHINE learning , *GENE expression , *PROGNOSTIC tests , *BIOLOGICAL tags , *SARCOMA - Abstract
Based on morphology it is often challenging to distinguish between the many different soft tissue sarcoma subtypes. Moreover, outcome of disease is highly variable even between patients with the same disease. Machine learning on transcriptome sequencing data could be a valuable new tool to understand differences between and within entities. Here we used machine learning analysis to identify novel diagnostic and prognostic markers and therapeutic targets for soft tissue sarcomas. Gene expression data was used from the Cancer Genome Atlas, the Genotype-Tissue Expression data and the French Sarcoma Group. We identified three groups of tumors that overlap in their molecular profile as seen with unsupervised t-Distributed Stochastic Neighbor Embedding clustering and a deep neural network. The three groups corresponded to subtypes that are morphologically overlapping. Using a random forest algorithm, we identified novel diagnostic markers for soft tissue sarcoma that distinguished between synovial sarcoma and MPNST, and that we validated using qRT-PCR in an independent series. Next, we identified prognostic genes that are strong predictors of disease outcome when used in a k-nearest neighbor algorithm. The prognostic genes were further validated in expression data from the French Sarcoma Group. One of these, HMMR, was validated in an independent series of leiomyosarcomas using immunohistochemistry on tissue micro array as a prognostic gene for disease-free interval. Furthermore, reconstruction of regulatory networks combined with data from the Connectivity Map showed, amongst others, that HDAC inhibitors could be a potential effective therapy for multiple soft tissue sarcoma subtypes. A viability assay with two HDAC inhibitors confirmed that both leiomyosarcoma and synovial sarcoma are sensitive to HDAC inhibition. In this study we identified novel diagnostic markers, prognostic markers and therapeutic leads from multiple soft tissue sarcoma gene expression datasets. Thus, machine learning algorithms are powerful new tools to improve our understanding of rare tumor entities. [ABSTRACT FROM AUTHOR] more...
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- 2019
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240. Facial cues to age perception using three-dimensional analysis.
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Imai, Takeo and Okami, Kyoko
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SENSORY perception , *3-D animation , *AGING , *CRANIOMETRY , *HUMAN skin color , *BIOMETRIC identification - Abstract
To clarify cues for age perception, the three-dimensional head and face forms of Japanese women were analyzed. It is known that age-related transformations are mainly caused by changes in soft tissue during adulthood. A homologous polygon model was created by fitting template meshes to each study participant to obtain three-dimensional data for analyzing whole head and face forms. Using principal component analysis of the vertices coordinates of these models, 26 principal components were extracted (contribution ratios >0.5%), which accounted for more than 90% of the total variance. Among the principal components, five had a significant correlation with the perceived ages of the participants (p < 0.05). Transformations with these principal components in the age-related direction produced aged faces. Moreover, the older the perceived age, the larger the ratio of age-manifesting participants, namely participants who had one or more age-related principal component score greater than +1.0 σ in the age-related direction. Therefore, these five principal components were regarded as aging factors. A cluster analysis of the five aging factors revealed that all of the participants fell into one of four groups, meaning that specific combinations of factors could be used as cues for age perception in each group. These results suggest that Japanese women can be classified into four groups according to age-related transformations of soft tissue in the face. [ABSTRACT FROM AUTHOR] more...
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- 2019
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241. A guide for using NIH Image J for single slice cross-sectional area and composition analysis of the thigh from computed tomography.
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Long, Douglas E., Villasante Tezanos, Alejandro G., Wise, James N., Kern, Philip A., Bamman, Marcas M., Peterson, Charlotte A., and Dennis, Richard A.
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COMPUTED tomography , *SKELETAL muscle physiology , *THIGH muscles , *EXERCISE physiology , *COMPUTER software - Abstract
Reports using computed tomography (CT) to estimate thigh skeletal muscle cross-sectional area and mean muscle attenuation are often difficult to evaluate due to inconsistent methods of quantification and/or poorly described analysis methods. This CT tutorial provides step-by-step instructions in using free, NIH Image J software to quantify both muscle size and composition in the mid-thigh, which was validated against a robust commercially available software, SliceOmatic. CT scans of the mid-thigh were analyzed from 101 healthy individuals aged 65 and older. Mean cross-sectional area and mean attenuation values are presented across seven defined Hounsfield unit (HU) ranges along with the percent contribution of each region to the total mid-thigh area. Inter-software correlation coefficients ranged from R2 = 0.92–0.99 for all specific area comparisons measured using the Image J method compared to SliceOmatic. We recommend reporting individual HU ranges for all areas measured. Although HU range 0–100 includes the majority of skeletal muscle area, HU range -29 to 150 appears to be the most inclusive for quantifying total thigh muscle. Reporting all HU ranges is necessary to determine the relative contribution of each, as they may be differentially affected by age, obesity, disease, and exercise. This standardized operating procedure will facilitate consistency among investigators reporting computed tomography characteristics of the thigh on single slice images. Trial Registration: ClinicalTrials.gov . [ABSTRACT FROM AUTHOR] more...
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- 2019
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242. A method for automatic forensic facial reconstruction based on dense statistics of soft tissue thickness.
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Gietzen, Thomas, Brylka, Robert, Achenbach, Jascha, zum Hebel, Katja, Schömer, Elmar, Botsch, Mario, Schwanecke, Ulrich, and Schulze, Ralf
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SOFT tissue infections , *COMPUTED tomography , *FACIAL expression , *SENSORY perception , *TETRAHEDRAL coordinates - Abstract
In this paper, we present a method for automated estimation of a human face given a skull remain. Our proposed method is based on three statistical models. A volumetric (tetrahedral) skull model encoding the variations of different skulls, a surface head model encoding the head variations, and a dense statistic of facial soft tissue thickness (FSTT). All data are automatically derived from computed tomography (CT) head scans and optical face scans. In order to obtain a proper dense FSTT statistic, we register a skull model to each skull extracted from a CT scan and determine the FSTT value for each vertex of the skull model towards the associated extracted skin surface. The FSTT values at predefined landmarks from our statistic are well in agreement with data from the literature. To recover a face from a skull remain, we first fit our skull model to the given skull. Next, we generate spheres with radius of the respective FSTT value obtained from our statistic at each vertex of the registered skull. Finally, we fit a head model to the union of all spheres. The proposed automated method enables a probabilistic face-estimation that facilitates forensic recovery even from incomplete skull remains. The FSTT statistic allows the generation of plausible head variants, which can be adjusted intuitively using principal component analysis. We validate our face recovery process using an anonymized head CT scan. The estimation generated from the given skull visually compares well with the skin surface extracted from the CT scan itself. [ABSTRACT FROM AUTHOR] more...
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- 2019
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243. Assessment of intraductal carcinoma in situ (DCIS) using grating-based X-ray phase-contrast CT at conventional X-ray sources: An experimental ex-vivo study.
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Hellerhoff, Karin, Birnbacher, Lorenz, Sztrókay-Gaul, Anikó, Grandl, Susanne, Auweter, Sigrid, Willner, Marian, Marschner, Mathias, Mayr, Doris, Reiser, Maximilian F., Pfeiffer, Franz, and Herzen, Julia more...
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DUCTAL carcinoma , *COMPUTED tomography , *X-ray imaging , *CANCER diagnosis , *THREE-dimensional imaging - Abstract
Background: The extent of intraductal carcinoma in situ (DCIS) is commonly underestimated due to the discontinuous growth and lack of microcalcifications. Specimen radiography has been established to reduce the rate of re-excision. However, the predictive value for margin assessment with conventional specimen radiography for DCIS is low. In this study we assessed the potential of grating-based phase-contrast computed tomography (GBPC-CT) at conventional X-ray sources for specimen tomography of DCIS containing samples. Materials and methods: GBPC-CT was performed on four ex-vivo breast specimens containing DCIS and invasive carcinoma of non-specific type. Phase-contrast and absorption-based datasets were manually matched with corresponding histological slices as the standard of reference. Results: Matching of CT images and histology was successful. GBPC-CT showed an improved soft tissue contrast compared to absorption-based images revealing more histological details in the same sections. Non-calcifying DCIS exceeding the invasive tumor could be correlated to areas of dilated bright ducts around the tumor. Conclusions: GBPC-CT imaging at conventional X-ray sources offers improved depiction quality for the imaging of breast tissue samples compared to absorption-based imaging, allows the identification of diagnostically relevant tissue details, and provides full three-dimensional assessment of sample margins. [ABSTRACT FROM AUTHOR] more...
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- 2019
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244. Polymeric 3D scaffolds for tissue regeneration: Evaluation of biopolymer nanocomposite reinforced with cellulose nanofibrils.
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Campodoni, Elisabetta, Heggset, Ellinor B., Rashad, Ahmad, Ramírez-Rodríguez, Gloria B., Mustafa, Kamal, Syverud, Kristin, Tampieri, Anna, and Sandri, Monica
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TISSUE scaffolds , *BONE regeneration , *BIOPOLYMERS , *NANOCOMPOSITE materials , *CELLULOSE fibers , *BIOCOMPATIBILITY - Abstract
Abstract 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. Graphical abstract Unlabelled Image Highlights • The scaffolds' biodegradability is controlled exploiting the cross-linking reactions. • The role of CNF as nano-reinforcement is confirmed and discussed. • The scaffolds' performances are tailored modifying the polymeric blends. • The scaffolds are able to promote and support cell adhesion and proliferation. [ABSTRACT FROM AUTHOR] more...
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- 2019
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245. Determinación del panel de inmunohistoquímica más útil para el diagnóstico de certeza de las neoplasias mesenquimatosas malignas de tejidos blandos.
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De Luna-Sánchez, Marcela Patricia, Soriano-Rosas, Juan, and Mora-Mendoza, Isabel
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Introduction: Malignant mesenchymal neoplasms tumors with great local and metastatic destructive effects. Immunohistochemistry (IHC) antibodies of recent appearance are currently available that can support the diagnosis of certainty. Objective: To evaluate the usefulness of IHC as an auxiliary tool for the diagnosis of certainty of these neoplasms; determining its prevalence and age distribution in our population. Material and methods: Observational, ambispective, cross-sectional and descriptive study, collected the histopathological diagnoses of malignant mesenchymal malignancies of soft tissues emitted in the Department of Pathological Anatomy from January 2012 to June 2017. IHC antibodies were performed (MDM-2, CDK-4, TLE-1, MUC-4 and SOX-10) in different sarcomas to determine its diagnostic utility. Results: 110 cases were collected, in 54 evaluated with MDM-2 and CDK-4 greater specificity was observed in liposarcomas, nine synovial sarcomas with TLE-1 with positivity of 100% in all cases, four malignant tumors of nerve sheath with SOX-10 and S-100 confirming utility in the diagnosis. Conclusions: IHC is a useful tool for the diagnosis of malignant mesenchymal neoplasms, since it gives lines of differentiation in specific tumors that help to guide the pathologist towards a diagnosis of certainty. [ABSTRACT FROM AUTHOR] more...
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- 2019
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246. CT and MR imaging in the local staging of primary malignant musculoskeletal neoplasms: Report of the Radiology Diagnostic Oncology Group.
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Panicek, DM, Gatsonis, C, Rosenthal, DI, Seeger, LL, Huvos, AG, Moore, SG, Caudry, DJ, Palmer, WE, and McNeil, BJ
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Humans ,Bone Neoplasms ,Soft Tissue Neoplasms ,Muscle Neoplasms ,Observer Variation ,Tomography ,X-Ray Computed ,Magnetic Resonance Imaging ,Neoplasm Staging ,Sensitivity and Specificity ,ROC Curve ,Adolescent ,Adult ,Aged ,Aged ,80 and over ,Middle Aged ,Child ,Female ,Male ,bone neoplasms ,staging ,computed tomography (CT) ,comparative studies ,magnetic resonance (MR) ,comparative studies ,receiver operating characteristic (ROC) curve ,soft tissues ,neoplasms ,Tomography ,X-Ray Computed ,and over ,bone neoplasms ,staging ,computed tomography ,comparative studies ,magnetic resonance ,soft tissues ,neoplasms ,Nuclear Medicine & Medical Imaging ,Medical and Health Sciences - Abstract
PurposeTo assess the relative accuracies of computed tomography (CT) and magnetic resonance (MR) imaging in the local staging of primary malignant bone and soft-tissue tumors.Materials and methodsAt four institutions, 367 eligible patients (aged 6-89 years) with malignant bone or soft-tissue neoplasms in selected anatomic sites were enrolled. Patients underwent both CT and MR imaging within 4 weeks before surgery. In each patient, CT scans were interpreted independently by two radiologists and MR images by two other radiologists at the enrolling institution. The CT and MR images were then interpreted together by two of those radiologists and subsequently reread at the other institutions. Imaging and histopathologic findings were compared and were supplemented when needed with surgical findings. Receiver operating characteristic curve analysis and descriptive statistical analysis were performed.ResultsCases were analyzable in 316 patients: 183 had primary bone tumors; 133 had primary soft-tissue tumors. There was no statistically significant difference between CT and MR imaging in determining tumor involvement of muscle, bone, joints, or neurovascular structures. The combined interpretation of CT and MR images did not statistically significantly improve accuracy. Interreader variability was similar for both modalities.ConclusionCT and MR imaging are equally accurate in the local staging of malignant bone and soft-tissue neoplasms in the specific anatomic sites studied. more...
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- 1997
247. Engineering the perfect mattress: The influence of substrate mechanics on deep tissue stresses in supine.
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Rayward, Lionel, Pearcy, Mark, Kerr, Graham, Pivonka, Peter, and Little, J Paige
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FINITE element method , *FURNITURE design , *HUMAN comfort , *SLEEP hygiene , *PRESSURE , *BODY movement , *SACRUM , *SUPINE position , *ADIPOSE tissues - Abstract
With increasing global interest in sleep hygiene, sleep ergonomics is an area that has been largely understudied. During sleep individuals turn over during the night to restore blood flow in occluded blood vessels, indicating that control of local tissue pressure may play a role in improving sleep comfort. This study investigates the influence of mattress stiffness on tissue compressive stresses during supine lying. A subject-specific 3D finite element (FE) model of the pelvis area has been developed to simulate supine lying on substrates of varying firmness. Constitutive parameters for the adipose-skin tissue and muscle-organ tissue were calibrated using a novel application of the inverse finite element method. The compressive stress was consistently greatest in the muscle interfacing the sacrum at 18.5 kPa on the soft foam, and 30.9 kPa on the firm foam. From soft to firm, the compressive stress increased by 67% at the sacrum, 20% at the ischium, 42% at the lesser trochanter, and 50% at the skin. The non-linearity of the foam substrate had a pressure distributing effect, relieving the peak compressive stresses at the sacrum, indicating that it may be possible to design arrays of foam substrates that can provide most efficient pressure relief. • First study to investigate the effects of mattress stiffness on deep tissue stresses. • Muscle interfacing the sacrum experiences the greatest compressive stress. • Non-linear mechanical characteristics of foam redistributes pressure effectively. [ABSTRACT FROM AUTHOR] more...
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- 2023
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248. Fine needle aspiration cytology of head and neck lesions and its correlation with histopathology
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R Pathak, KBR Prasad, SK Rauniyar, S Pudasaini, K Pande, S Koirala, S Kafle, A Jha, S Chalise, and AS Basnyat
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Fine needle aspiration cytology ,Histopathology ,Lymph node ,Thyroid ,Salivary gland ,Soft tissues ,Pathology ,RB1-214 - Abstract
Background: Fine needle aspiration cytology is a minimally invasive technique used in the initial diagnosis of different types of lesions located in head and neck region commonly originating from cervical lymph node, thyroid gland, salivary glands and soft tissues. The objective of this study was to evaluate the diagnostic accuracy, sensitivity and speci city of FNAC in various head and neck lesions in correlation with their histopathological examination. Materials and methods: A hospital based prospective study was conducted among 209 patients with palpable head and neck region swellings in the Department of Pathology, Bhaktapur Cancer Hospital and the Department of Pathology, Nepal Medical College from August 2014 to July 2015. FNAC were done from palpable masses of head and neck regions. Data entry and analysis were done using SPSS 17. Result: There were 209 FNAC cases enrolled, out of which lymph node lesions (n=128) were the most common lesions followed by thyroid (n=40), other soft tissues (n=27) and salivary gland (n=14). Reactive lymph nodes, colloid goiter, epidermoid cyst and sialadenosis were the predominant diagnosis of lymph nodes, thyroid gland, soft tissues and salivary gland respectively. Highest accuracy, sensitivity and speci city were observed in thyroid gland, salivary gland and soft tissues. However, four false negative results for malignancy were reported in lymph node lesions. Conclusion: Head and neck region swellings are the commonly encountered conditions. FNAC being highly accurate, sensitive and speci c makes it useful and reliable procedure for screening and diagnosis of palpable masses in head and neck region. more...
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- 2016
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249. Injury Occurrence in Amateur Rugby: Prospective Analysis of Specific Predictors over One Half- Season
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Bjelanović, Luka, Mijatović, Dragan, Sekulić, Damir, Modrić, Toni, Geets Kesić, Marijana, Klasnja, Aleksandar, Drid, Patrik, and Veršić, Šime
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rugby union ,soft tissues ,bones ,playing positions ,pain ,injury prevalence - Abstract
Background and objectives: The incidence of injuries in rugby is extremely high, but studies have rarely examined the predictors of injury in amateur players. This study aimed to systematically analyse sports and injury factors as potential predictors of musculoskeletal injuries in senior-level amateur rugby players. Methods: The participants in this study were 101 senior-level rugby players from Croatia (average of 24.64 years old). At baseline, all participants were tested on sociodemographic and anthropometric parameters (age, body height and mass), consumption of dietary supplements, preseason injury status and training volume, and sport factors (position in game). Data on injury occurrence (dependent variable), prevalence of pain, training status, and characteristics of the played match were surveyed prospectively once a week during the three-month period (one half- season). Results: The logistic regression revealed a higher injury occurrence in forward players of the 1st row, 2nd row (OR = 5.07 ; 95% CI: 1.64– 15.69), and center (OR = 4.72 ; 95% CI: 1.28– 14.31), with reference to outside back players. When observed univariately, higher body mass, higher level of competition, more weekly training sessions, self-perceived pain, and playing with pain were significant injury risk factors. The multivariate logistic regression identified pre- season injury (OR = 1.30, 95% CI: 1.09–1.52), higher level of the game/match (OR = 1.44, 95% CI: 1.13–1.76), higher body mass (OR = 1.03, 95% CI: 1.01–1.05), and pain prevalence (OR = 5.71, 95% CI: 3.22-7.70) as multivariate predictors of injury occurrence over the season. Conclusion: The results of this study showed that among sport factors, the playing position, level of competition, and training exposure represent major injury risk factors. Therefore, in order to reduce the number of injuries, special emphasis should be placed on the specific tackling technique of forward players, which could both increase their situational efficiency and protect them from injuries. Additionally, perceived pain, injury history, and playing with injury were noted among injury factors as the ones that can be predictors of future injuries. In that manner, it is important that coaching and medical staff monitor players with previous injuries and with pain symptoms in order to act preventively against injury occurrence. more...
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- 2023
250. A 3D Scanning System for Inverse Analysis of Moist Biological Samples: Design and Validation Using Tendon Fascicle Bundles
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Sylwia Dabrowska, Martyna Ekiert, Kaja Wojcik, Marek Kalemba, and Andrzej Mlyniec
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non-contact measurement ,three-dimensional imaging ,tendon ,tendon fascicle bundles ,3D model ,soft tissues ,Chemical technology ,TP1-1185 - Abstract
In this article, we present the design and validation of a non-contact scanning system for the development of a three-dimensional (3D) model of moist biological samples. Due to the irregular shapes and low stiffness of soft tissue samples, the use of a non-contact, reliable geometry scanning system with good accuracy and repeatability is required. We propose a reliable 3D scanning system consisting of a blue light profile sensor, stationary and rotating frames with stepper motors, gears and a five-phase stepping motor unit, single-axis robot, control system, and replaceable sample grips, which once mounted onto the sample, are used for both scanning and mechanical tests. The proposed system was validated by comparison of the cross-sectional areas calculated based on 3D models, digital caliper, and vision-based methods. Validation was done on regularly-shaped samples, a wooden twig, as well as tendon fascicle bundles. The 3D profiles were used for the development of the 3D computational model of the sample, including surface concavities. Our system allowed for 3D model development of samples with a relative error of less than 1.2% and high repeatability in approximately three minutes. This was crucial for the extraction of the mechanical properties and subsequent inverse analysis, enabling the calibration of complex material models. more...
- Published
- 2020
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