10 research outputs found

    Enamel matrix derivative Emdogain® as an adjuvant for a laterally-positioned flap in the treatment of gingival recession: an electron microscopic appraisal

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    Enamel matrix derivative (EMD), such as Emdogain®, has been suggested for the improvement of wound healing in periodontal surgical therapy. The present qualitative study seeks to illustrate the ultrastructural changes associated with a human gingival wound at 10 days after the application of EMD as an adjunct to a laterally-positioned flap in a patient with gingival recession. An otherwise healthy patient, who had been suffering from bilateral gingival recession defects on teeth #23 and #26, was studied. One defect was treated with a laterally-positioned flap, while the other was treated with a combination of EMD and a laterally-positioned flap. Ten days after the operation gingival biopsy specimens were obtained from the dentogingival region and examined using a transmission electron microscope. A considerable difference was found in both the cellular and extracellular phases of EMD and non-EMD sites. The fibroblasts of EMD site were more rounded with plump cytoplasms and euchromatic nuclei. A well-developed rough endoplasmic reticulum and numerous mitochondria could be detected. In contrast, the fibroblasts of non-EMD site were of flattened spindle-like morphology. While the signs of apoptosis could rarely be detected at EMD site, apoptotic bodies and ultra-structural evidence of apoptosis (crescent-like heterochromatic nuclei and dilated nuclear envelopes) were consistent features at non-EMD site. The extracellular matrix at EMD site mainly consisted of well-organised collagen fibres, while non-EMD site contained sparse and incompletely-formed collagen fibres. Coccoid bacteria were noted within the extracellular matrix and neutrophils at non-EMD site. It seems that EMD may enhance certain features of gingival wound healing, which may be attributable to its anti-apoptotic, anti-bacterial or anti-inflammatory properties

    A rare variation of the vertebral artery

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    Variations of the vertebrobasilar arterial complex are important with regard to their potential clinical impact. We present an unusual case of the vertebral artery, in which the left vertebral artery in its ascent in the neck through the transverse foramina passed posteriorly between the transverse processes of C3 and C4 and supplied the posterior muscles of the neck without continuing intracranially. Albeit speculatively, we hypothesise that the variation of the vertebral artery reported here was caused by degeneration of the proximal portion of the left postcostal longitudinal anastomosis (i.e. C1 and C2 intersegmental arteries) in the context of a persistent third cervical intersegmental artery. Our case is unique in that the left vertebral artery terminated extracranially. Knowledge of the variations of the vertebrobasilar arterial complex is important for surgeons operating at the skull base, craniocervical junction, and cervical region, and for clinicians interpreting the imaging of this region

    The effects of an electromagnetic field on the boundary tissue of the seminiferous tubules of the rat: a light and transmission electron microscope study

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    Human beings are unavoidably exposed to ambient electromagnetic fields (EMF) generated from various electrical devices and from power transmission lines. Controversy exists about the effects of EMF on various organs. One of the critical issues is that EMF may adversely affect the reproductive system. In order to examine this 30 rat pups were exposed to 50 Hz EMF (non-ionising radiation) during in utero development (approximately 3 weeks) and postnatal life (5 weeks). Groups of exposed rats were subsequently left in an environment free of EMF in order to observe recovery, if any, from the changes induced by EMF on the boundary tissue of the seminiferous tubules. The materials were processed and observed under a light and a transmission electron microscope. In the experimental rats boundary tissue was found disrupted at various layers. This tissue showed infoldings, which were perhaps due to the loss of collagen and reticular fibrils from the inner and outer non-cellular layers. The outer non-cellular layer, which was thinner than that of the control, was stripped away from the myoid cell layer in multiple regions, giving a “blister-like” appearance. The myoid cells showed fewer polyribosomes, pinocytotic vesicles and glycogen granules. Most mitochondria were found to lack cristae. The connections between individual myoid cells were apparently lost. There were signs of recovery in the boundary tissue following withdrawal from EMF exposure. These results suggest that EMF exposure may cause profound changes in the boundary tissue of the seminiferous tubules. Therefore exposure to EMF may result in pathological changes that lead to subfertility and infertility

    Tech united Eindhoven middle-size league winner 2019

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    After the sequence of winning the RoboCup Middle-Size League (MSL) in even years only (2012, 2014, 2016, 2018), Tech United Eindhoven achieved its first RoboCup win during an odd year at RoboCup 2019. This paper presents an evaluation of the tournament and describes the most notable scientific improvements made in preparation of the tournament. These developments consist of our solution to (unforeseen) localisation problems and the improvements in the control architecture of our eight-wheeled robot. The progress in the shooting lever is elaborated as well as the advancements in the arbitrary ball-detection in order to improve our scoring during the Technical Challenge. Additionally, research towards the application of artificial intelligence in predicting the actions of opponents and recognizing the appearance of the opponent robots will be presented

    Tech united Eindhoven middle-size league winner 2019

    No full text
    After the sequence of winning the RoboCup Middle-Size League (MSL) in even years only (2012, 2014, 2016, 2018), Tech United Eindhoven achieved its first RoboCup win during an odd year at RoboCup 2019. This paper presents an evaluation of the tournament and describes the most notable scientific improvements made in preparation of the tournament. These developments consist of our solution to (unforeseen) localisation problems and the improvements in the control architecture of our eight-wheeled robot. The progress in the shooting lever is elaborated as well as the advancements in the arbitrary ball-detection in order to improve our scoring during the Technical Challenge. Additionally, research towards the application of artificial intelligence in predicting the actions of opponents and recognizing the appearance of the opponent robots will be presented. After the sequence of winning the RoboCup Middle-Size League (MSL) in even years only (2012, 2014, 2016, 2018), Tech United Eindhoven achieved its first RoboCup win during an odd year at RoboCup 2019. This paper presents an evaluation of the tournament and describes the most notable scientific improvements made in preparation of the tournament. These developments consist of our solution to (unforeseen) localisation problems and the improvements in the control architecture of our eight-wheeled robot. The progress in the shooting lever is elaborated as well as the advancements in the arbitrary ball-detection in order to improve our scoring during the Technical Challenge. Additionally, research towards the application of artificial intelligence in predicting the actions of opponents and recognizing the appearance of the opponent robots will be presented

    Toward superlensing with metal-dielectric composites and multilayers

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    We report on the fabrication of two types of adjustable, near-field superlens designs: metal-dielectric composites and metal-dielectric multilayer films. We fabricated a variety of films with different materials, thicknesses and compositions. These samples were characterized physically and optically to determine their film composition, quality, and optical responses. Our results on metal-dielectric composites indicate that although the real part of the effective permittivity generally follows effective medium theory predictions, the imaginary part does not and substantially higher losses are observed. Going forward, it appears that multilayer metal-dielectric designs are more suitable for sub-diffraction imaging applications because they could provide both tunability and low loss

    Understanding metric-related pitfalls in image analysis validation

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    Validation metrics are key for tracking scientific progress and bridging the current chasm between artificial intelligence research and its translation into practice. However, increasing evidence shows that, particularly in image analysis, metrics are often chosen inadequately. Although taking into account the individual strengths, weaknesses and limitations of validation metrics is a critical prerequisite to making educated choices, the relevant knowledge is currently scattered and poorly accessible to individual researchers. Based on a multistage Delphi process conducted by a multidisciplinary expert consortium as well as extensive community feedback, the present work provides a reliable and comprehensive common point of access to information on pitfalls related to validation metrics in image analysis. Although focused on biomedical image analysis, the addressed pitfalls generalize across application domains and are categorized according to a newly created, domain-agnostic taxonomy. The work serves to enhance global comprehension of a key topic in image analysis validation

    Metrics reloaded: recommendations for image analysis validation

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    Increasing evidence shows that flaws in machine learning (ML) algorithm validation are an underestimated global problem. In biomedical image analysis, chosen performance metrics often do not reflect the domain interest, and thus fail to adequately measure scientific progress and hinder translation of ML techniques into practice. To overcome this, we created Metrics Reloaded, a comprehensive framework guiding researchers in the problem-aware selection of metrics. Developed by a large international consortium in a multistage Delphi process, it is based on the novel concept of a problem fingerprint-a structured representation of the given problem that captures all aspects that are relevant for metric selection, from the domain interest to the properties of the target structure(s), dataset and algorithm output. On the basis of the problem fingerprint, users are guided through the process of choosing and applying appropriate validation metrics while being made aware of potential pitfalls. Metrics Reloaded targets image analysis problems that can be interpreted as classification tasks at image, object or pixel level, namely image-level classification, object detection, semantic segmentation and instance segmentation tasks. To improve the user experience, we implemented the framework in the Metrics Reloaded online tool. Following the convergence of ML methodology across application domains, Metrics Reloaded fosters the convergence of validation methodology. Its applicability is demonstrated for various biomedical use cases
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