39 research outputs found

    Регіональні й глобальні наслідки незалежності Косово

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    У статті розглянуто регіональні й міжнародні аспекти проголошення незалежності Косово. Проаналізовано конфліктні аспекти косовської проблеми у регіональному й глобальному контекстах.В статье рассматриваются региональные и международные аспекты провозглашения независимости Косово. Проанализировано конфликтные аспекты косовской проблемы в региональном и глобальном контекстах.The article presents the regional and international aspects of Kosovo Independents. Special attention is to the conflict of Kosovo in the regional and global context

    T2* mapping in an equine articular groove model - visualizing changes in collagen orientation

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    T2* mapping is promising for the evaluation of articular cartilage collagen. In this work, a groove model in a large animal is used as a model for post-traumatic arthritis. We hypothesized that T2* mapping could be employed to differentiate between healthy and (subtly) damaged cartilage. Eight carpal joints were obtained from four adult Shetland ponies that had been included in the groove study. In this model, grooves were surgically created on the proximal articular surface of the intermediate carpal bone (radiocarpal joint) and the radial facet of the third carpal bone (middle carpal joint) by either coarse disruption or sharp incision. After nine months, T2* mapping of the entire carpal joint was carried out on a 7.0T whole body magnetic resonance imaging (MRI) scanner by means of a gradient echo multi echo sequence. Afterwards, assessment of collagen orientation was carried out based on Picrosirius Red-stained histological sections, visualized by polarized light microscopy (PLM). The average T2* relaxation time in grooved samples was lower than in contralateral control sites. Opposite to the grooved areas, the "kissing sites" had a higher average T2* relaxation time than the grooved sites. PLM showed mild changes in orientation of the collagen fibers, particularly around blunt grooves. This work shows that T2* relaxation times are different in healthy cartilage versus (early) damaged cartilage, as induced by the equine groove model. Additionally, the average T2* relaxation times are different in kissing lesions versus the grooved sites. This article is protected by copyright. All rights reserved

    T2* mapping in an equine articular groove model: Visualizing changes in collagen orientation

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    T2* mapping is promising for the evaluation of articular cartilage collagen. In this work, a groove model in a large animal is used as a model for posttraumatic arthritis. We hypothesized that T2* mapping could be employed to differentiate between healthy and (subtly) damaged cartilage. Eight carpal joints were obtained from four adult Shetland ponies that had been included in the groove study. In this model, grooves were surgically created on the proximal articular surface of the intermediate carpal bone (radiocarpal joint) and the radial facet of the third carpal bone (middle carpal joint) by either coarse disruption or sharp incision. After 9 months, T2* mapping of the entire carpal joint was carried out on a 7.0-T whole-body magnetic resonance imaging (MRI) scanner by means of a gradient echo multi-echo sequence. Afterwards, assessment of collagen orientation was carried out based on Picrosirius Red-stained histological sections, visualized by polarized light microscopy (PLM). The average T2* relaxation time in grooved samples was lower than in contralateral control sites. Opposite to the grooved areas, the "kissing sites" had a higher average T2* relaxation time than the grooved sites. PLM showed mild changes in orientation of the collagen fibers, particularly around blunt grooves. This work shows that T2* relaxation times are different in healthy cartilage vs (early) damaged cartilage, as induced by the equine groove model. Additionally, the average T2* relaxation times are different in kissing lesions vs the grooved sites

    История возникновения католической общины города Севастополя и строительство римско-католического костёла

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    Цель статьи – проследить этапы формирования римско-католической общины города Севастополя и историю строительства римско-католического костёла во имя Священномученника Климента Римского

    Composition, architecture and biomechanical properties of articular cartilage in differently loaded areas of the equine stifle

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    Background: Strategies for articular cartilage repair need to take into account topographical differences in tissue composition and architecture to achieve durable functional outcome. These have not yet been investigated in the equine stifle. Objectives: To analyse the biochemical composition and architecture of three differently loaded areas of the equine stifle. We hypothesise that site differences correlate with the biomechanical characteristics of the cartilage. Study design: Ex vivo study. Methods: Thirty osteochondral plugs per location were harvested from the lateral trochlear ridge (LTR), the distal intertrochlear groove (DITG) and the medial femoral condyle (MFC). These underwent biochemical, biomechanical and structural analysis. A linear mixed model with location as a fixed factor and horse as a random factor was applied, followed by pair-wise comparisons of estimated means with false discovery rate correction, to test for differences between locations. Correlations between biochemical and biomechanical parameters were tested using Spearman's correlation coefficient. Results: Glycosaminoglycan content was different between all sites (estimated mean [95% confidence interval (CI)] for LTR 75.4 [64.5, 88.2], for intercondylar notch (ICN) 37.3 [31.9, 43.6], for MFC 93.7 [80.1109.6] μg/mg dry weight), as were equilibrium modulus (LTR2.20 [1.96, 2.46], ICN0.48 [0.37, 0.6], MFC1.36 [1.17, 1.56] MPa), dynamic modulus (LTR7.33 [6.54, 8.17], ICN4.38 [3.77, 5.03], MFC5.62 [4.93, 6.36] MPa) and viscosity (LTR7.49 [6.76, 8.26], ICN16.99 [15.88, 18.14], MFC8.7 [7.91,9.5]°). The two weightbearing areas (LTR and MCF) and the non-weightbearing area (ICN) differed in collagen content (LTR 139 [127, 152], ICN176[162, 191], MFC 127[115, 139] μg/mg dry weight), parallelism index and angle of collagen fibres. The strongest correlations were between proteoglycan content and equilibrium modulus (r: 0.642; p: 0.001), dynamic modulus (r: 0.554; p < 0.001) and phase shift (r: −0.675; p < 0.001), and between collagen orientation angle and equilibrium modulus (r: −0.612; p < 0.001), dynamic modulus (r: −0.424; p < 0.001) and phase shift (r: 0.609; p < 0.001). Main limitations: Only a single sample per location was analysed. Conclusions: There were significant differences in cartilage biochemical composition, biomechanics and architecture between the three differently loaded sites. The biochemical and structural composition correlated with the mechanical characteristics. These differences need to be acknowledged by designing cartilage repair strategies

    Site- and Zone-Dependent Changes in Proteoglycan Content and Biomechanical Properties of Bluntly and Sharply Grooved Equine Articular Cartilage

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    In this study, we mapped and quantified changes of proteoglycan (PG) content and biomechanical properties in articular cartilage in which either blunt or sharp grooves had been made, both close to the groove and more remote of it, and at the opposing joint surface (kissing site) in equine carpal joints. In nine adult Shetland ponies, standardized blunt and sharp grooves were surgically made in the radiocarpal and middle carpal joints of a randomly chosen front limb. The contralateral control limb was sham-operated. At 39 weeks after surgery, ponies were euthanized. In 10 regions of interest (ROIs) (six remote from the grooves and four directly around the grooves), PG content as a function of tissue-depth and distance-to-groove was estimated using digital densitometry. Biomechanical properties of the cartilage were evaluated in the six ROIs remote from the grooves. Compared to control joints, whole tissue depth PG loss was found in sites adjacent to sharp and, to a larger extent, blunt grooves. Also, superficial PG loss of the surgically untouched kissing cartilage layers was observed. Significant PG loss was observed up to 300 µm (sharp) and at 500 µm (blunt) from the groove into the surrounding tissue. Equilibrium modulus was lower in grooved cartilage than in controls. Grooves, in particular blunt grooves, gave rise to severe PG loss close to the grooved sites and to mild degeneration more remote from the grooves in both sharply and bluntly grooved cartilage and at the kissing sites, resulting in loss of mechanical strength over the 9-month period

    Dual-contrast computed tomography enables detection of equine posttraumatic osteoarthritis in vitro

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    To prevent the progression of posttraumatic osteoarthritis, assessment of cartilage composition is critical for effective treatment planning. Posttraumatic changes include proteoglycan (PG) loss and elevated water content. Quantitative dual-energy computed tomography (QDECT) provides a means to diagnose these changes. Here, we determine the potential of QDECT to evaluate tissue quality surrounding cartilage lesions in an equine model, hypothesizing that QDECT allows detection of posttraumatic degeneration by providing quantitative information on PG and water contents based on the partitions of cationic and nonionic agents in a contrast mixture. Posttraumatic osteoarthritic samples were obtained from a cartilage repair study in which full-thickness chondral defects were created surgically in both stifles of seven Shetland ponies. Control samples were collected from three nonoperated ponies. The experimental (n = 14) and control samples (n = 6) were immersed in the contrast agent mixture and the distributions of the agents were determined at various diffusion time points. As a reference, equilibrium moduli, dynamic moduli, and PG content were measured. Significant differences (p < 0.05) in partitions between the experimental and control samples were demonstrated with cationic contrast agent at 30 min, 60 min, and 20 h, and with non-ionic agent at 60 and 120 min. Significant Spearman's rank correlations were obtained at 20 and 24 h (rho = 0.482-0.693) between the partition of cationic contrast agent, cartilage biomechanical properties, and PG content. QDECT enables evaluation of posttraumatic changes surrounding a lesion and quantification of PG content, thus advancing the diagnostics of the extent and severity of cartilage injuries

    Structural, compositional, and functional effects of blunt and sharp cartilage damage on the joint: a 9-month equine groove model study

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    This study aimed to quantify the long-term progression of blunt and sharp cartilage defects and their effect on joint homeostasis and function of the equine carpus. In nine adult Shetland ponies, the cartilage in the radiocarpal and middle carpal joint of one front limb was grooved (blunt or sharp randomized). The ponies were subjected to an 8-week exercise protocol and sacrificed at 39 weeks. Structural and compositional alterations in joint tissues were evaluated in vivo using serial radiographs, synovial biopsies, and synovial fluid samples. Joint function was monitored by quantitative gait analysis. Macroscopic, microscopic, and biomechanical evaluation of the cartilage, and assessment of subchondral bone parameters were performed ex vivo. Grooved cartilage showed higher OARSI microscopy scores than the contra-lateral sham-operated controls (p <0.0001). Blunt-grooved cartilage scored higher than sharp-grooved cartilage (p = 0.007) and fixed charge density around these grooves was lower (p = 0.006). Equilibrium and instantaneous moduli trended lower in grooved cartilage than their controls (significant for radiocarpal joints). Changes in other tissues included a 3 to 7-fold change in IL-6 expression in synovium from grooved joints at week 23 (p = 0.042) and an increased CPII/C2C ratio in synovial fluid from blunt-grooved joints at week 35 (p = 0.010). Gait analysis outcome revealed mild, gradually increasing lameness. In conclusion, blunt and, to a lesser extent, sharp grooves in combination with a period of moderate exercise, lead to mild degeneration in equine carpal cartilage over a 9-month period, but the effect on overall joint health remains limited. This article is protected by copyright. All rights reserved

    Machine learning augmented near-infrared spectroscopy: In vivo follow-up of cartilage defects

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    OBJECTIVE: To assess the potential of near-infrared spectroscopy (NIRS) for in vivo arthroscopic monitoring of cartilage defects. METHOD: Sharp and blunt cartilage grooves were induced in the radiocarpal and intercarpal joints of Shetland ponies and monitored at baseline (0 weeks) and at three follow-up time points (11, 23, and 39 weeks) by measuring near-infrared spectra in vivo at and around the grooves. The animals were sacrificed after 39 weeks and the joints were harvested. Spectra were reacquired ex vivo to ensure reliability of in vivo measurements and for reference analyses. Additionally, cartilage thickness and instantaneous modulus were determined via computed tomography and mechanical testing, respectively. The relationship between the ex vivo spectra and cartilage reference properties was determined using convolutional neural network. RESULTS: For the independent test, the trained networks yielded significant correlations for cartilage thickness (ρ=0.473) and instantaneous modulus (ρ=0.498). These networks were used to predict the reference properties at baseline and follow-ups. In the radiocarpal joint, cartilage thickness increased significantly with both groove types after baseline and remained swollen. Additionally, at 39 weeks, a significant difference was observed in cartilage thickness between controls and sharp grooves. For the instantaneous modulus, significant decrease was observed with both groove types in the radiocarpal joint from baseline to 23 and 39 weeks. CONCLUSION: NIRS combined with machine learning enabled determination of cartilage properties in vivo, thereby providing longitudinal evaluation of post-intervention injury development. Additionally, radiocarpal joints demonstrated more vulnerability to cartilage degeneration after damage than intercarpal joints
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