The controversy over the association between statins use and progression of age-related macular degeneration: a mini review

Vasileios Peponis1, Spyridon E Chalkiadakis1, Stefanos Bonovas2,3, Nikolaos M Sitaras21Athens Eye Hospital, 2nd Eye Clinic, Athens, Greece; 2Department of Pharmacology, School of Medicine, University of Athens, Greece; 3Center for Diseases Control and Prevention, Athens, GreeceObjective: Age-related macular degeneration (AMD) is the leading cause of blindness in ¬western societies. Statins comprise a class of pharmacological agents that reduce plasma cholesterol levels, and have been shown to prevent progression of atherosclerosis and reduce cardiovascular mortality. The relationship between these medications and AMD has been evaluated in several recent studies. Herein, we examine the current evidence for an association between statin use and risk of AMD.Methods: Literature database search (Medline, Scopus, and Science Citation Index Expanded) for articles published up to March 2010, using particular search terms.Results: From the current evidence available, it is not safe to conclude upon the assumption of a protective effect of statins against age-related maculopathy and AMD.Conclusion: There is a need for large scale prospective studies with a long follow-up period and accurate assessment of AMD to further explore this matter.Keywords: age-related macular degeneration (AMD), blindness, statin use, controvers

Research and development of hydrogen carrier based solutions for hydrogen compression and storage

publishedVersio

ΑΝΑΠΤΥΞΗ ΣΥΣΤΗΜΑΤΟΣ ΠΡΟΣΒΑΣΗΣ ΣΕ ΕΛΕΓΧΟΜΕΝΟ ΧΩΡΟ ΜΕ ΧΡΗΣΗ KEYPAD & ΜΙΚΡΟΕΠΕΞΕΡΓΑΣΤΩΝ ΑΝΟΙΚΤΟΥ ΛΟΓΙΣΜΙΚΟΥ

Η παρούσα διπλωματική έχει ως στόχο αφενός μεν να αποτελέσει μια γενική εισαγωγή στις βασικές δομές, στη θεωρία λειτουργίας και στις εφαρμογές των μικροελεγκτών Arduino και αφετέρου να παρουσιάσει αναλυτικά την υλοποίηση ενός συστήματος ελεγχόμενης πρόσβασης. Πιο συγκεκριμένα, στο Κεφάλαιο 1 γίνεται μια ιστορική αναδρομή στην δημιουργία του συστήματος Arduino. Στο Κεφάλαιο 2 παρουσιάζονται αναλυτικά τα δομικά στοιχεία και εξετάζονται σε λεπτομέρεια τα τεχνικά χαρακτηριστικά του συστήματος Arduino mega, αλλά και των επιμέρους μονάδων που χρησιμοποιήθηκαν. Στο Κεφάλαιο 3 παρουσιάζεται το λογισμικό που έχει χρησιμοποιηθεί. Στο Κεφάλαιο 4 περιγράφεται η υλοποίηση και παρουσιάζεται ο τρόπος διασύνδεσης των επιμέρους συστημάτων που έχουν χρησιμοποιηθεί. Τέλος, στο Κεφάλαιο 5 περιγράφεται και σχολιάζεται αναλυτικά ο κώδικας που έχει κατασκευαστεί για να υλοποιήσει το συγκεκριμένο σύστημα πρόσβασης σε ελεγχόμενο χώρο, ενώ ο κώδικας συγκεντρωμένος μπορεί να βρεθεί στο παράρτημα.This dissertation has two aims, firstly to give a general introduction into the basic structure, theory of operation and applications of Arduino systems and secondly, to present in detail the design of a particular access control system. Chapter 1 makes a throwback in the creation of Arduino Project. The Chapter 2 presents analytical components and detail examination for the technical characteristics of Arduino Mega ADK R3 system, but also examines the rest of the hardware modules used in this dissertation. Chapter 3 describes the software used for the implementation of this dissertation. Chapter 4 describes the implementation and provides a detailed presentation of how the components used have been interfaced to produce the characteristics of the corresponding application. Finally, Chapter 5 describes and discusses in detail the code that has been engineered to deliver the access control system. The whole code can be found in the Annex

Διαχείριση ηφαιστειακού κινδύνου στο ηφαίστειο της Νισύρου

Οι ηφαιστειακές εκρήξεις είναι ένα από τα πιο καταστροφικά φυσικά φαινόμενα που έχει ν' αντιμετωπίσει η ανθρωπότητα και η κοινωνία. Στον πλανήτη, τη δεδομένη χρονική στιγμή υπάρχουν 1500 εν δυνάμει ενεργά ηφαίστεια εκ των οποίων τα 600 έχουν εκραγεί κάποια στιγμή στο παρελθόν. Επιπλέον, υπάρχουν και πολλά ηφαιστειακά κέντρα τα οποία δεν έχουν εντοπιστεί ακόμη και παραμένουν άγνωστα. Στη χώρα μας, από τα 39 συνολικά ηφαίστεια, τα μόνα ενεργά εντοπίζονται σε περιοχές του Ν. Αιγαίου. Η Ελλάδα είναι μια χώρα με έντονη ηφαιστειακή δραστηριότητα. Για τον λόγο αυτό είναι επιτακτική η ανάγκη για τη μελέτη και την παρακολούθηση των ηφαιστείων, προκειμένου ο κόσμος να γνωρίζει τους κινδύνους και να μπορεί να ενημερωθεί και να προστατευτεί σε περίπτωση ηφαιστειακής έκρηξης. Η παρούσα διπλωματική εργασία αναφέρεται σε δράσεις που πρέπει να υλοποιούνται από ειδικούς, επιστήμονες, την πολιτεία και τους αρμόδιους φορείς της πολιτείας. Θα γίνει αναφορά στην επικινδυνότητα του ηφαιστειακού κέντρου της Νισύρου. Στόχος της είναι να περιγράψει την εικόνα των ηφαιστείων σήμερα και την ηφαιστειακή επικινδυνότητα του λαμβάνοντας υπόψη τις νέες τεχνολογικές εφαρμογές. Στην αρχή θα γίνει μια σύντομη βιβλιογραφική ανασκόπηση των βασικών σημείων που σχετίζονται με τις ηφαιστειακές εκρήξεις. Στη συνέχεια, θα γίνει αναφορά στο ηφαίστειο της Νισύρου, στην ιστορική του εξέλιξη , τα ηφαιστειολογικά χαρακτηριστικά του, την ηφαιστειακή δραστηριότητα και επικινδυνότητα του. Τέλος θα γίνει μια σύντομη αναφορά στις μεθόδους πρόβλεψης και διαχείρισης των ηφαιστειακών εκρήξεων. Η μέθοδος που θα χρησιμοποιηθεί για τη συγγραφή της παρούσας εργασίας είναι η βιβλιογραφική ανασκόπηση. Πιο συγκεκριμένα για την παρούσα μελέτη θα συλλεχθούν και θα μελετηθούν πλήθος ερευνητικών άρθρων που αφορούν τον ορισμό, την περιγραφή, την ταξινόμηση των ηφαιστείων, τα χαρακτηριστικά του ηφαιστείου της Θήρας και Νισύρου την ηφαιστειακή δραστηριότητα του και την επικινδυνότητα που παρουσιάζει, καθώς επίσης και την πρόβλεψη και διαχείριση των ηφαιστειακών εκρήξεων.Volcanic eruptions are one of the most devastating natural phenomena that humanity and society have ever faced. There are currently 1,500 potentially active volcanoes on the planet at present, 600 of which have erupted at some point in the past. In addition, there are many volcanic centers that have not yet been identified and remain unknown. In our country, out of the 39 total volcanoes, the only ones are actively located in areas of the South Aegean. Greece is a country with intense volcanic activity. For this reason, the need to study and monitor volcanoes is imperative, so that people are aware of the dangers and can be informed and protected in the event of a volcanic eruption. This dissertation refers to actions that must be implemented by experts, scientists, the state and the competent state bodies. Reference will be made to the danger of the volcanic center of Nisyros. Its aim is to describe the image of volcanoes today and its volcanic hazard taking into account new technological applications. At the beginning there will be a brief bibliographic review of the main points related to volcanic eruptions. Then, reference will be made to the volcano of Nisyros, its historical development, its volcanic characteristics, its volcanic activity and danger. Finally, a brief reference will be made to the methods of forecasting and managing volcanic eruptions. The method that will be used to write this paper is the literature review. More specifically, for the present study, a number of research articles will be collected and studied regarding the definition, description, classification of volcanoes, the characteristics of the volcano of Thira and Nisyros, its volcanic activity and the danger it presents, as well as the forecast and management of volcanic eruptions

Pilot autonomous hybrid hydrogen refueling station utilizing a metal hydride compressor covering local transportation needs

The need for decreasing carbon emissions in the transportation sector in order to meet the targets of the European Union by 2030, inevitably leads to the large scale adoption of cleaner alternatives. Hydrogen fueled vehicles could possibly provide one such alternative, if we could assume that the necessary infrastructure would be widely available throughout Europe. Already, the European Union has committed to the construction of a significant number of Hydrogen Refueling Stations (HRS) by year 2025 and in view of that, there is a need of developing suitable configurations for the production, compression, storage and dispensing of green hydrogen to hydrogen fueled vehicles. This work presents an autonomous hybrid system which produces green hydrogen by PV- powered water electrolysis (PEM), which is subsequently compressed by a novel metal hydride hydrogen compressor to pressures up to 200 bar. This pilot HRS will meet the daily demand of 2 scooters and a golf cart which have been transformed, in order for their electric motor to be powered by a hydrogen fuel cell instead of a battery. An important element of the work which is presented, revolves around the integration of the metal hydride compressor with the rest of the system, and how this integration won’t hinder its functionality. The complete system design and layout is presented, while the results from the system operation could give a good idea regarding the optimal system sizing for similar large scale applications

Incarcerated spontaneous transdiaphragmatic intercostal hernia

AbstractIntroductionProlapse of abdominal viscera into the thoracic subcutis through the chest wall is known as transdiaphragmatic intercostal hernia (TIH). Herein, we present the first case of spontaneous TIH presenting as a thoracoabdominal emergency.Presentation of caseA 78-year-old male presented with acute left thoracoabdominal pain following a sudden bulge at the left posterolateral chest wall corresponding to a partially reducible soft tissue mass with ecchymosis at the overlying skin. Paroxysmal cough during the last four days was also reported along with a prolonged daily application of a special tight abdominal belt that used while milking sheep. CT-scan of the abdomen showed intrathoracic proptosis of the splenic flexure through a defect of the left hemidiaphragm and subcutaneous prolapse of the herniated colon through the 7th intercostal space. On laparotomy, the herniated colon showed signs of ischemic necrosis leading to segmental colectomy followed by repair of the diaphragmatic defect.DiscussionThe clinical diagnosis of spontaneous TIH demands very high index of suspicion and thorough patient's history. In this case the daily elevation of the intraabdominal pressure due to an abdominal milking belt might have caused gradual slimming and loosening of the diaphragm and the intercostals muscles rendering them vulnerable to sudden increases of the thoracoabdominal pressure due to violent coughing. Such a hypothesis is reasonable in the absence of traumatic injury in this patient.ConclusionSpontaneous TIH should be suspected in patients presenting with a sudden palpable chest wall bulge and associated thoracoabdominal symptoms in the absence of preceding injury

The million dollar handshake: secure and attested communications in the cloud

Summarization: The number of applications and services that are hosted on cloud platforms is constantly increasing. Nowadays, more and more applications are hosted as services on cloud platforms, co-existing with other services in a mutually untrusted environment. Facilities such as virtual machines, containers and encrypted communication channels aim to offer isolation between the various applications and protect sensitive user data. However, such techniques are not always able to provide a secure execution environment for sensitive applications nor they offer guarantees that data are not monitored by an honest but curious provider once they reach the cloud infrastructure. The recent advancements of trusted execution environments within commodity processors, such as Intel SGX, provide a secure reverse sandbox, where code and data are isolated even from the underlying operating system. Moreover, Intel SGX provides a remote attestation mechanism, allowing the communicating parties to verify their identity as well as prove that code is executed on hardware-assisted software enclaves. Many approaches try to ensure code and data integrity, as well as enforce channel encryption schemes such as TLS, however, these techniques are not enough to achieve complete isolation and secure communications without hardware assistance or are not efficient in terms of performance. In this work, we design and implement a practical attestation system that allows the service provider to offer a seamless attestation service between the hosted applications and the end clients. Furthermore, we implement a novel caching system that is capable to eliminate the latencies introduced by the remote attestation process. Our approach allows the parties to attest one another before each communication attempt, with improved performance when compared to a standard TLS handshake.Παρουσιάστηκε στο: 2020 IEEE 13th International Conference on Cloud Computin