114 research outputs found

    Validation of Different Combination of Three Reversing Half-Hitches Alternating Posts (RHAPs) Effects on Arthroscopic Knot Integrity

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    Introduction. With arthroscopic techniques being used, the importanceof knot tying has been examined. Previous literaturehas examined the use of reversing half-hitches on alternatingposts (RHAPs) on knot security. Separately, there has been researchregarding different suture materials commonly used inthe operating room. The specific aim of this study was to validatethe effect of different stacked half-hitch configuration anddifferent braided suture materials on arthroscopic knot integrity. Methods. Three different suture materials tied withfive different RHAPs in arthroscopic knots were compared.A single load-to-failure test was performed andthe mean ultimate clinical failure load was obtained. Results. Significant knot holding strength improvement wasfound when one half-hitch was reversed as compared to baselineknot. When two of the half-hitches were reversed, therewas a greater improvement with all knots having a mean ultimateclinical failure load greater than 150 newtons (N). Comparisonof the suture materials demonstrated a higher meanultimate clinical failure load when Force Fiber® was used andat least one half-hitch was reversed. Knots tied with eitherForce Fiber® or Orthocord® showed 0% chance of knot slippagewhile knots tied with FiberWire® or braided fishing linehad about 10 and 30% knot slippage chances, respectively. Conclusion. A significant effect was observed in regards to bothstacked half-hitch configuration and suture materials used onknot loop and knot security. Caution should be used with tyingthree RHAPs in arthroscopic surgery, particularly witha standard knot pusher and arthroscopic cannulas. The findingsof this study indicated the importance of three RHAPsin performing arthroscopic knot tying and provided evidenceregarding discrepancies of maximum clinical failure loads observedbetween orthopaedic surgeons, thereby leading to bettersurgical outcomes in the future. KS J Med 2017;10(2):35-39

    Quadriceps Strength and Knee Function After Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon Bone Autograft: A Preliminary Report

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    Introduction. The purpose of this study was to evaluate quadriceps strength and knee function after anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon bone (QTB) autograft. Methods. Preliminary data were extracted from an ongoing prospective cohort study in which the operative extremity was compared to non-operative extremity. Patients from 14 to 40 years of age who had an ACL reconstruction with QTB autograft volunteered to have knee assessment including quadriceps isokinetic strength measures and functional knee testing at 6 and 12 months postoperatively. Paired t-tests were conducted to compare postoperative strength and function scores on participants who had minimum 1-year post-surgical follow-up. Results. Patients had a significant recovery of quadriceps strength as determined by isokinetic testing and single leg hop test. For 31 participants, quadriceps strength of the operative leg measured at 60 deg/sec was 63% of the non-operative leg at 6 months, increasing to 79% at 1 year (p < 0.001); when measured at 180 deg/sec, these values were 68% at 6 months, increasing to 82% at 1 year (p < 0.001). For 30 participants, single leg hop functional scores of the operative leg were 80% of the non-operative leg at 6 months, increasing to 91% at 1 year (p < 0.001). Conclusions. After QTB autograft for ACL reconstruction, there were significant gains in quadriceps strength and knee function from 6 months to 1 year postoperative. These findings indicate the QTB is an acceptable ACL reconstruction option

    Project-based learning course on metabolic network modelling in computational systems biology.

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    Project-based learning (PBL) is a dynamic student-centred teaching method that encourages students to solve real-life problems while fostering engagement and critical thinking. Here, we report on a PBL course on metabolic network modelling that has been running for several years within the Master in Integrated Systems Biology (MISB) at the University of Luxembourg. This 2-week full-time block course comprises an introduction into the core concepts and methods of constraint-based modelling (CBM), applied to toy models and large-scale networks alongside the preparation of individual student projects in week 1 and, in week 2, the presentation and execution of these projects. We describe in detail the schedule and content of the course, exemplary student projects, and reflect on outcomes and lessons learned. PBL requires the full engagement of students and teachers and gives a rewarding teaching experience. The presented course can serve as a role model and inspiration for other similar courses

    Phlebotominae (Diptera: Psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

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    In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites

    Testing a global standard for quantifying species recovery and assessing conservation impact.

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    Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard

    Supraspinatus Fatty Infiltration Correlation with Handgrip Strength, Shoulder Strength, and Validated Patient-Reported Outcome Measures in Patients with Rotator Cuff Tears

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    Introduction. The purpose of this study was to investigate the relationships between supraspinatus atrophy on magnetic resonance imaging (MRI) and other objective parameters in patients with rotator cuff tears. We hypothesized that high-grade supraspinatus fatty infiltration would be negatively correlated with handgrip strength, shoulder strength and patient-reported outcome measures (PROMs). Methods. Patients with MRI-proven rotator cuff tears treated by a single sports medicine fellowship-trained orthopaedist at a single institution underwent comprehensive preoperative evaluation including bilateral handgrip and shoulder strength measurements with dynamometers and multiple online questionnaires from the Surgical Outcomes SystemTM(Arthrex, Naples, FL). Available shoulder MRIs were reviewed to grade supraspinatus fatty infiltration severity according to the 5-tier Goutallier system and an alternate 3-tier classification scheme. Difference analysis and Spearman (rho) rank order correlation were applied to the collected data to define the relationships between supraspinatus fatty infiltration and key variables including handgrip strength, shoulder strength and scores derived from the shoulder PROMs. Results. Ninety of the 121 patients enrolled in the study had shoulder MRIs available for review. We found no correlation between supraspinatus fatty infiltration and handgrip strength, shoulder abduction strength or any of the 7 common shoulder PROM scores we evaluated. There was statistically significant albeit weak correlation between MRI-derived fatty infiltration and shoulder external rotation strength. Conclusions. Contrary to our hypothesis, high-grade supraspinatus fatty infiltration is largely unrelated to and should not be considered predictive of handgrip strength, shoulder strength or common shoulder PROM scores

    Data from: Automated segmentation of complex patterns in biological tissues: lessons from stingray tessellated cartilage

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    Introduction - Many biological structures show recurring tiling patterns on one structural level or the other. Current image acquisition techniques are able to resolve those tiling patterns to allow quantitative analyses. The resulting image data, however, may contain an enormous number of elements. This renders manual image analysis infeasible, in particular when statistical analysis is to be conducted, requiring a larger number of image data to be analyzed. As a consequence, the analysis process needs to be automated to a large degree. In this paper, we describe a multi-step image segmentation pipeline for the automated segmentation of the calcified cartilage into individual tesserae from computed tomography images of skeletal elements of stingrays. Methods - Besides applying state-of-the-art algorithms like anisotropic diffusion smoothing, local thresholding for foreground segmentation, distance map calculation, and hierarchical watershed, we exploit a graph-based representation for fast correction of the segmentation. In addition, we propose a new distance map that is computed only in the plane that locally best approximates the calcified cartilage. This distance map drastically improves the separation of individual tesserae. We apply our segmentation pipeline to hyomandibulae from three individuals of the round stingray (Urobatis halleri), varying both in age and size. Results - Each of the hyomandibula datasets contains approximately 3000 tesserae. To evaluate the quality of the automated segmentation, four expert users manually generated ground truth segmentations of small parts of one hyomandibula. These ground truth segmentations allowed us to compare the segmentation quality w.r.t. individual tesserae. Additionally, to investigate the segmentation quality of whole skeletal elements, landmarks were manually placed on all tesserae and their positions were then compared to the segmented tesserae. With the proposed segmentation pipeline, we sped up the processing of a single skeletal element from days or weeks to a few hours
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