109 research outputs found

    MONITORING OF SURFACE DISPLACEMENTS IN THE KALOCHORI AREA (THESSALONIKI, GREECE) USING A LOCAL GNSS NETWORK

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    Οι εδαφικές κινήσεις στην περιοχή του Καλοχωρίου μετρήθηκαν από το Γεωδυναμικό Ινστιτούτο του ΕΑΑ με χρήση τοπικού δικτύου GNSS. Το δίκτυο ιδρύθηκε τον Οκτώβριο του 2013 στο πλαίσιο του έργου INDES-MUSA και μετρήθηκε τέσσερις (4) φορές μεταξύ Οκτωβρίου 2013 - Απρίλιου του 2015.Τα σημεία του δικτύου είναι 18 και αποτελούν μπουλόνια σε δρόμους, πλατείες καθώς και καρφιά σε βάθρα της ΓΥΣ. Τα αποτελέσματα (στο σύστημα αναφοράς ITRF 2008) που προέκυψαν από επεξεργασία με το λογισμικό GAMIT δείχνουν κατακόρυφες μετατοπίσεις της τάξεως των σύν-πλήν 2 εκατοστών, εκτός από την περίμετρο του φράγματος του Καλοχωρίου το οποίο ανυψώθηκε από 2-5 εκατοστά. Οι οριζόντιες μετακινήσεις δεν δείχνουν κάποια συσχέτιση με τεκτονικές κινήσεις της ευρύτερης περιοχής.The ground motions in the Kalochori region (well known for its subsidence history during the 2nd half of 20th century) were investigated by NOA using a mobile GNSS (GPS) network, comprising 18 stations. The network was measured four (4) times during the period October 2013 - April 2015 under the framework of the research project INDES-MUSA. Our GPS measurements were processed with GAMIT software and show vertical (ITRF 2008) motions ranging from -2 cm to +2 cm (i.e. just above the margins of measurement error) with the exception of the Kalochori dam where an uplift of 2-5 cm was observed. We also found no evidence for local (non-tectonic) motions and/or interseismic strain

    A systematic review and meta-analysis of outcomes after elective surgery for ulcerative colitis.

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    AIM: Approximately 20%-30% of patients with ulcerative colitis (UC) will undergo surgery during their disease course, the vast majority being elective due to chronic refractory disease. The risks of elective surgery are reported variably. The aim of this systematic review and meta-analysis is to summarize the outcomes after elective surgery for UC. METHODS: A systematic review was conducted that analysed studies reporting outcomes for elective surgery in the modern era (>2002). It was prospectively registered on the PROSPERO database (ref: CRD42018115513). Searches were performed of Embase and MEDLINE on 15 January 2019. Outcomes were split by operation performed. Primary outcome was quality of life; secondary outcomes were early, late and functional outcomes after surgery. Outcomes reported in five or more studies underwent a meta-analysis of incidence using random effects. Heterogeneity is reported with I2 , and publication bias was assessed using Doi plots and the Luis Furuya-Kanamori index. RESULTS: A total of 34 studies were included (11 774 patients). Quality of life was reported in 12 studies, with variable and contrasting results. Thirteen outcomes (eight early surgical complications, five functional outcomes) were included in the formal meta-analysis, all of which were outcomes for ileal pouch-anal anastomosis (IPAA). A further 71 outcomes were reported (50 IPAA, 21 end ileostomy). Only 14 of 84 outcomes received formal definitions, with high inter-study variation of definitions. CONCLUSION: Outcomes after elective surgery for UC are variably defined. This systematic review and meta-analysis highlights the range of reported incidences and provides practical information that facilitates shared decision making in clinical practice

    Three-dimensional reconstruction of coronary arteries and plaque morphology using CT angiography - comparison and registration with IVUS

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    BACKGROUND: The aim of this study is to present a new methodology for three-dimensional (3D) reconstruction of coronary arteries and plaque morphology using Computed Tomography Angiography (CTA). METHODS: The methodology is summarized in six stages: 1) pre-processing of the initial raw images, 2) rough estimation of the lumen and outer vessel wall borders and approximation of the vessel’s centerline, 3) manual adaptation of plaque parameters, 4) accurate extraction of the luminal centerline, 5) detection of the lumen - outer vessel wall borders and calcium plaque region, and 6) finally 3D surface construction. RESULTS: The methodology was compared to the estimations of a recently presented Intravascular Ultrasound (IVUS) plaque characterization method. The correlation coefficients for calcium volume, surface area, length and angle vessel were 0.79, 0.86, 0.95 and 0.88, respectively. Additionally, when comparing the inner and outer vessel wall volumes of the reconstructed arteries produced by IVUS and CTA the observed correlation was 0.87 and 0.83, respectively. CONCLUSIONS: The results indicated that the proposed methodology is fast and accurate and thus it is likely in the future to have applications in research and clinical arena

    Primary right atrium angiosarcoma mimicking pericarditis

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    <p>Abstract</p> <p>Background</p> <p>Primary cardiac neoplasms occur rarely and most of them are benign. Malignant tumors including angiosarcoma are extremely rare and have a non specific clinical presentation and a poor prognosis.</p> <p>Case presentation</p> <p>We present a case of a young male who was transferred to our hospital because of shock and multiple organ failure after a complicated pericardial biopsy. During the previous seven months he presented with recurrent episodes of pericardial effusions and tamponade. Chest computed tomography revealed a mass in the right atrium, infiltrating the myocardium and pericardium. During emergency surgery that followed, the patient died because of uncontrolled hemorrhage. Autopsy revealed the mass of the right atrium, which was identified on histological examination as primary cardiac angiosarcoma.</p> <p>Conclusion</p> <p>This case highlights the difficulties both in early diagnosis and in the management of patients with cardiac angiosarcoma.</p

    Three-dimensional reconstruction of coronary arteries and plaque morphology using CT angiography - comparison and registration with IVUS

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    Background: The aim of this study is to present a new methodology for three-dimensional (3D) reconstruction of coronary arteries and plaque morphology using Computed Tomography Angiography (CTA). Methods: The methodology is summarized in six stages: 1) pre-processing of the initial raw images, 2) rough estimation of the lumen and outer vessel wall borders and approximation of the vessel's centerline, 3) manual adaptation of plaque parameters, 4) accurate extraction of the luminal centerline, 5) detection of the lumen - outer vessel wall borders and calcium plaque region, and 6) finally 3D surface construction. Results: The methodology was compared to the estimations of a recently presented Intravascular Ultrasound (IVUS) plaque characterization method. The correlation coefficients for calcium volume, surface area, length and angle vessel were 0.79, 0.86, 0.95 and 0.88, respectively. Additionally, when comparing the inner and outer vessel wall volumes of the reconstructed arteries produced by IVUS and CTA the observed correlation was 0.87 and 0.83, respectively. Conclusions: The results indicated that the proposed methodology is fast and accurate and thus it is likely in the future to have applications in research and clinical arena

    Digital biomarker-based individualized prognosis for people at risk of dementia

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    Background: Research investigating treatments and interventions for cognitive decline fail due to difficulties in accurately recognizing behavioral signatures in the presymptomatic stages of the disease. For this validation study, we took our previously constructed digital biomarker-based prognostic models and focused on generalizability and robustness of the models. Method: We validated prognostic models characterizing subjects using digital biomarkers in a longitudinal, multi-site, 40-month prospective study collecting data in memory clinics, general practitioner offices, and home environments. Results: Our models were able to accurately discriminate between healthy subjects and individuals at risk to progress to dementia within 3 years. The model was also able to differentiate between people with or without amyloid neuropathology and classify fast and slow cognitive decliners with a very good diagnostic performance. Conclusion: Digital biomarker prognostic models can be a useful tool to assist large-scale population screening for the early detection of cognitive impairment and patient monitoring over time

    Fast, accurate, and reliable detection of damage in aircraft composites by advanced synergistic infrared thermography and phased array techniques

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    This paper presents an advanced methodology for the detection of damage in aircraft composite materials based on the sensor fusion of two image-based non-destructive evaluation techniques. Both of the techniques, phased-array ultrasonics and infra-red thermography, are benchmarked on an aircraft-grade painted composite material skin panel with stringers. The sensors systems for carrying out the inspections have been developed and miniaturized for being integrated on a vortex-robotic platform inspector, in the framework of a larger research initiative, the Horizon-2020 ‘CompInnova’ project

    Cryoglobulinemic vasculitis in primary Sj\uf6gren's Syndrome: Clinical presentation, association with lymphoma and comparison with Hepatitis C-related disease

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    Objective: To describe the clinical spectrum of cryoglobulinemic vasculitis (CV) in primary Sj\uf6gren's syndrome (pSS), investigate its relation to lymphoma and identify the differences with hepatitis C virus (HCV) related CV. Methods: From a multicentre study population of consecutive pSS patients, those who had been evaluated for cryoglobulins and fulfilled the 2011 classification criteria for CV were identified retrospectively. pSS-CV patients were matched with pSS patients without cryoglobulins (1:2) and HCV-CV patients (1:1). Clinical, laboratory and outcome features were analyzed. A data driven logistic regression model was applied for pSS-CV patients and their pSS cryoglobulin negative controls to identify independent features associated with lymphoma. Results: 1083 pSS patients were tested for cryoglobulins. 115 (10.6%) had cryoglobulinemia and 71 (6.5%) fulfilled the classification criteria for CV. pSS-CV patients had higher frequency of extraglandular manifestations and lymphoma (OR=9.87, 95% CI: 4.7\u201320.9) compared to pSS patients without cryoglobulins. Purpura was the commonest vasculitic manifestation (90%), presenting at disease onset in 39% of patients. One third of pSS-CV patients developed B-cell lymphoma within the first 5 years of CV course, with cryoglobulinemia being the strongest independent lymphoma associated feature. Compared to HCV-CV patients, pSS-CV individuals displayed more frequently lymphadenopathy, type II IgMk cryoglobulins and lymphoma (OR = 6.12, 95% CI: 2.7\u201314.4) and less frequently C4 hypocomplementemia and peripheral neuropathy. Conclusion: pSS-CV has a severe clinical course, overshadowing the typical clinical manifestations of pSS and higher risk for early lymphoma development compared to HCV related CV. Though infrequent, pSS-CV constitutes a distinct severe clinical phenotype of pSS

    Immuno-modulatory effects of intervertebral disc cells

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    Low back pain is a highly prevalent, chronic, and costly medical condition predominantly triggered by intervertebral disc degeneration (IDD). IDD is often caused by structural and biochemical changes in intervertebral discs (IVD) that prompt a pathologic shift from an anabolic to catabolic state, affecting extracellular matrix (ECM) production, enzyme generation, cytokine and chemokine production, neurotrophic and angiogenic factor production. The IVD is an immune-privileged organ. However, during degeneration immune cells and inflammatory factors can infiltrate through defects in the cartilage endplate and annulus fibrosus fissures, further accelerating the catabolic environment. Remarkably, though, catabolic ECM disruption also occurs in the absence of immune cell infiltration, largely due to native disc cell production of catabolic enzymes and cytokines. An unbalanced metabolism could be induced by many different factors, including a harsh microenvironment, biomechanical cues, genetics, and infection. The complex, multifactorial nature of IDD brings the challenge of identifying key factors which initiate the degenerative cascade, eventually leading to back pain. These factors are often investigated through methods including animal models, 3D cell culture, bioreactors, and computational models. However, the crosstalk between the IVD, immune system, and shifted metabolism is frequently misconstrued, often with the assumption that the presence of cytokines and chemokines is synonymous to inflammation or an immune response, which is not true for the intact disc. Therefore, this review will tackle immunomodulatory and IVD cell roles in IDD, clarifying the differences between cellular involvements and implications for therapeutic development and assessing models used to explore inflammatory or catabolic IVD environments
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