Χωρική Ανάλυση Περιστατικών Έρευνας-Διάσωσης (Search and Rescue-SAR) στον Ελλαδικό Χώρο με Χρήση Γεωγραφικών Συστημάτων Πληροφοριών

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

Hemolymphangioma of the lower extremities in children: two case reports

Abstract Background and purpose Hemo-lymphangiomas are rare benign tumors that arise from congenital malformation of the vascular system. They are usually diagnosed at birth or early in childhood. The management of hemo-lymphangiomas in children remains challenging because complete resection is often difficult to be achieved and recurrences are common. Methods We present the case of two children with a mass on their left tibia. Imaging modalities, plain radiograph, Ultrasonography and Magnetic Resonance were used to investigate the nature of the mass, the anatomical relationship to the neighboring tissues and help planning the surgical resection. The dominant diagnosis was hemo-lymphangioma. Both lesions increased in size in a short period of follow-up thus we decided to proceed to surgical excision. The diagnosis of hemo-lymphangioma was confirmed by histological examination of the surgical specimen. Post-operatively, seroma was formed to the first patient, managed by placing a drainage and immobilizing the limb on a splint. The second patient experienced no complications post-operatively. After 12 months of follow-up both patients had no complications or recurrence. Conclusions Very few cases of hemo-lymphangiomas of the extremities have been reported in the literature. Those tumors can grow slowly and remain asymptomatic for a long period of time or may become aggressive and enlarge rapidly, without invasive ability though. Radical resection is the choice of treatment offering the lowest recurrence rates. Other therapeutic methods are: aspiration and drainage, cryotherapy, injection of sclerotic agents and radiotherapy; although none of those offers better results that the surgical excision.</p

The influence of the frequency of pulsating jets on the recirculation zone of a backward facing step. An experimental study

168 σ.Στην παρούσα εργασία διερευνήθηκε πειραματικά η επίδραση της συχνότητας παλλόμενων δεσμών αέρα στον έλεγχο της ροής απότομης διεύρυνσης. Ο αριθμός Reynolds της ροής ήταν Re = 8000, ενώ οι παλλόμενες δέσμες αέρα εισήχθησαν στη ροή από μια σχισμή, η οποία περιείχε 20 οπές, πολύ κοντά στην άνω ακμή της απότομης διεύρυνσης. Για τις μετρήσεις χρησιμοποιήθηκε η τεχνική PIV δύο διαστάσεων (2D-Particle Image Velocimetry) με σύστημα σκανδαλισμού. Τα αποτελέσματα έδειξαν ότι στη ροή σχηματίζονται δύο περιοχές ανακυκλοφορίας, μια κύρια ανθωρολογιακής φοράς (port όπως την αντιλαμβάνεται ένας παρατηρητής που κινείται μαζί με το ελεύ- θερο ρεύμα), η οποία εκτείνεται από την περιοχή απότομης διεύρυνσης μέχρι την περιοχή επανακόλλησης και μια δευτερεύουσα, η οποία είναι ωρολογιακής φοράς, βρίσκεται στην περιοχή της κάτω ακμής της απότομης διεύρυνσης και είναι πολύ μικρότερη της πρώτης. Το μήκος επανακόλλησης μεταβάλλεται με τη συχνότητα των δεσμών, ενώ υπάρχει μια συχνότητα στην οποία το μήκος γίνεται ελάχιστο. Όταν η ροή διεγείρεται με τη βέλτι- στη συχνότητα, ώστε να ισχύει St = 0.22 για τον αδιάστατο αριθμό Strouhal με βάση το ύψος H της απότομης διεύρυνσης, το μήκος επανακόλλησης μειώνεται κατά 21% περίπου σε σχέση με το μήκος χωρίς έλεγχο. Με την διεξαγωγή συγχρονισμένων μετρήσεων μέσα στην περίοδο της δέσμης, παρατηρήθηκε ότι το μήκος επανακόλλη- σης μεταβάλλεται κατά τη διάρκεια μιας περιόδου και η όλη διαδικασία είναι ένα ασταθές δυναμικό φαινόμενο. Συγχρονισμένες μετρήσεις κοντά στην απότομη διεύρυνση έδειξαν την ύπαρξη μιας δίνης, η οποία εκλύεται από το ύψος της άνω ακμής της απότομης διεύρυνσης και ταξιδεύει επεκτεινόμενη μέσα στην περίοδο προς το σημείο επανακόλλησης. Η ταχύτητά της Ux βρέθηκε περίπου σταθερή και ίση με 0.33U∞ και η Uy = 0.09U∞.In the present Diploma Thesis the effect of the frequency of pulsating jets on the recirculation zone of a backward facing step was experimentally investigated. A Re = 8000 was chosen as test case and periodic perturbation was introduced from a slot, containing 20 holes, near the step edge. A two dimensional particle image velocimeter (PIV) with a triggering mechanism was used in the flow-field measurements. The measurements showed that there are two recirculation bubbles in the flow, one major counter-clockwise bubble (port as received by a person travelling with the free stream), which expands from the step area to the recirculation region and a minor port clockwise bubble, which is formed near the bottom area of the step and is considerably smaller than the first one. The reattachment length varies with the perturbation frequency, while there exists an optimum frequency, in which the reattachment length is minimum. When perturbed with this optimum frequency, with which the nondimensional Strouhal number based on the step height H is St = 0.22, the reattachment length is reduced by almost 21% of the uncontrolled case. Performing synchronised measurements inside the jet period, it was observed that the reattachment length varies also in the period itself. The reattachment process is therefore a highly non-stable dynamic phenomenon. Synchronised measurements near the the backward facing step showed that there exists a vortex, which is released from the step edge and travels towards the reattachment region, expanding inside the period. This vortex is travelling with an almost stable velocity component, Ux = 0.33U∞ and a velocity component Uy = 0.09U∞.Γεώργιος Κ. Φιλιόπουλο

Genomic Damage in Endstage Renal Disease—Contribution of Uremic Toxins

Patients with end-stage renal disease (ESRD), whether on conservative, peritoneal or hemodialysis therapy, have elevated genomic damage in peripheral blood lymphocytes and an increased cancer incidence, especially of the kidney. The damage is possibly due to accumulation of uremic toxins like advanced glycation endproducts or homocysteine. However, other endogenous substances with genotoxic properties, which are increased in ESRD, could be involved, such as the blood pressure regulating hormones angiotensin II and aldosterone or the inflammatory cytokine TNF-α. This review provides an overview of genomic damage observed in ESRD patients, focuses on possible underlying causes and shows modulations of the damage by modern dialysis strategies and vitamin supplementation

Test performance of faecal occult blood testing for the detection of bowel cancer in people with chronic kidney disease (DETECT) protocol

<p>Abstract</p> <p>Background</p> <p>Cancer is a major cause of mortality and morbidity in patients with chronic kidney disease (CKD). In patients without kidney disease, screening is a major strategy for reducing the risk of cancer and improving the health outcomes for those who developed cancers by detecting treatable cancers at an early stage. Among those with CKD, the effectiveness, the efficacy and patients' preferences for cancer screening are unknown.</p> <p>Methods/Design</p> <p>This work describes the protocol for the DETECT study examining the effectiveness, efficiency and patient's perspectives of colorectal cancer screening using immunochemical faecal occult blood testing (iFOBT) for people with CKD. The aims of the DETECT study are 1) to determine the test performance characteristics of iFOBT screening in individuals with CKD, 2) to estimate the incremental costs and health benefits of iFOBT screening in CKD compared to no screening and 3) to elicit patients' perspective for colorectal cancer screening in the CKD population. Three different study designs will be used to explore the uncertainties surrounding colorectal cancer screening in CKD. A diagnostic test accuracy study of iFOBT screening will be conducted across all stages of CKD in patients ages 35-70. Using individually collected direct healthcare costs and outcomes from the diagnostic test accuracy study, cost-utility and cost-effective analyses will be performed to estimate the costs and health benefits of iFOBT screening in CKD. Qualitative in-depth interviews will be undertaken in a subset of participants from the diagnostic test accuracy study to investigate the perspectives, experiences, attitudes and beliefs about colorectal cancer screening among individuals with CKD.</p> <p>Discussion</p> <p>The DETECT study will target the three major unknowns about early cancer detection in CKD. Findings from our study will provide accurate and definitive estimates of screening efficacy and efficiency for colorectal cancer, and will allow better service planning and budgeting for early cancer detection in this at-risk population.</p> <p>The DETECT study is also registered with the Australia New Zealand Clinical Trials Registry <a href="http://www.anzctr.org.au/ACTRN12611000538943.aspx">ACTRN12611000538943</a></p

Uremic myopathy: Is oxidative stress implicated in muscle dysfunction in uremia?

© 2015 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fphys.2015.00102Renal failure is accompanied by progressive muscle weakness and premature fatigue, in part linked to hypokinesis and in part to uremic toxicity. These changes are associated with various detrimental biochemical and morphological alterations. All of these pathological parameters are collectively termed uremic myopathy. Various interventions while helpful can't fully remedy the pathological phenotype. Complex mechanisms that stimulate muscle dysfunction in uremia have been proposed, and oxidative stress could be implicated. Skeletal muscles continuously produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) at rest and more so during contraction. The aim of this mini review is to provide an update on recent advances in our understanding of how ROS and RNS generation might contribute to muscle dysfunction in uremia. Thus, a systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. While few studies met our criteria their findings are discussed making reference to other available literature data. Oxidative stress can direct muscle cells into a catabolic state and chronic exposure to it leads to wasting. Moreover, redox disturbances can significantly affect force production per se. We conclude that oxidative stress can be in part responsible for some aspects of uremic myopathy. Further research is needed to discern clear mechanisms and to help efforts to counteract muscle weakness and exercise intolerance in uremic patients.This work has been co-financed by the European Union (European Social Fund—ESF) and Greek national funds through the Operational Program “Educational and Lifelong Learning” of the National Strategic Reference Framework (NSRF)—Research Funding Program: Thales (MuscleFun Project-MIS 377260) Investing in knowledge society through the European Social Fund.Published versio