Μελέτη της μικροβιακής χλωρίδας των ενδοπροθέσεων του χοληδόχου πόρου σε ασθενείς που υποβάλλονται σε παγκρεατοδωδεκαδακτυλεκτομή μετά από ενδοσκοπική παλίνδρομη χολάγγειο-παγκρεατογραφία.

Εισαγωγή Η προεγχειρητική παροχέτευση των χοληφόρων προτάθηκε για πρώτη φορά από τον Whipple. Αν και μελέτες σε ζώα δείχνουν ότι η αποχέτευση των χολών πριν από την εκτομή του παγκρέατος βελτίωσε τα χειρουργικά αποτελέσματα, οι κλινικές μελέτες σε ανθρώπους δεν έδειξαν σταθερά ένα όφελος. Η προεγχειρητική στένωση των χοληφόρων συνδέεται με βακτηριακή επιμόλυνση της χολής και αυξημένο ποσοστό σηπτικών επιπλοκών μετά από Παγκρεατοδωδεκαδακτυλεκτομή. Σκοπός Η παρούσα μελέτη αποσκοπεί στην μελέτη της μικροβιακής χλωρίδας που αναπτύσσεται στα στεντ που τοποθετούνται με ERCP προεγχειρητική σε ασθενείς που περιφατήριο νεόπλασμα. Μέθοδος Τα δεδομένα συλλέχθηκαν αναδρομικά από μια προοπτικά καταγεγραμμένη βάση δεδομένων ασθενών, που υποβλήθηκαν σε Παγκρεατοδωδεκαδακτυλεκτομή για περιφατήριο νεόπλασμα στην Α΄ Προπαιδευτική Χειρουργική Κλινική του Εθνικού και Καποδιστριακού Πανεπιστημίου Αθηνών του ΓΝΑ Ιπποκράτειο την τελευταία δεκαετία 2010-2020. Αναλύθηκαν δεδομένα από 278 ασθενείς, 136 από αυτούς υπεβλήθησαν σε προεγχειρητική παροχέτευση με στεντ, 80 από τα στεντ εστάλησαν για καλλιέργεια και συμπεριλήφθηκαν στο τελικό δείγμα της μελέτης. Αποτελέσματα Το δείγμα της μελέτης αποτελούνταν από 80 ασθενείς , διάμεσης ηλικίας 65 ετών (IQR 6,0). Οι γυναίκες αποτελούσαν το 51,3% (Ν=41), με ΔΜΣ 25,1 kg/m2 (IQR 3,9). Όλοι οι ασθενείς υπεβλήθησαν σε επέμβαση Παγκρεατοδωδεκαδακτυλεκτομής για περιφατήρια νεοπλάσματα. Εστάλησαν 80 στεντ για καλλιέργεια , από αυτές τις καλλιέργειες 73 (91,3%) ήταν θετικές για κάποιο παθογόνο ενώ οι υπόλοιπες 7 (8,8%) ήταν στείρες. Οι μικροοργανισμοί κατά πλειοψηφία ήταν ευαίσθητη στα συνήθη αντιβιοτικά, με εξαίρεση την Klebsiella pneumoniae. Η σύγκριση αναμεσά στην ομάδα ασθενών με θετικές καλλιέργειες και αυτούς με αρνητικές καλλιέργειες δεν ανέδειξε στατιστικά σημαντικά αποτελέσματα (p<0,05), με εξαίρεση τις παραμέτρους της διάρκειας αναμονής σε ημέρες προ του χειρουργείου και το διάστημα παρουσίας ικτέρου. Συμπεράσματα Η ανάπτυξη διαφορετικής μικροχλωρίδας στα stent που τοποθετούνται ενδοσκοπικά κατά την διάρκεια της προεγχειρητικής ERCP είναι συχνό φαινόμενο. Δεν υπάρχει συσχέτιση της θετικής καλλιέργειας στεντ με την εμφάνιση επιπλοκών, αλλα στην συγκριση του αριθμού αναπτυσσομένων μικροβίων στα στεντ βρέθηκε ότι στην ομάδα των πολυμικροβιακών καλλιεργειών η παρουσία παγκρεατικού συριγγίου ηταν αυξημένη (p=0,032). Η μετεγχειρητική αντιμετώπιση σηπτικών επεισοδίων πρέπει να λαμβάνει υπόψιν το αποτέλεσμα των καλλιεργειών και του στεντ. Η εκτίμηση της παρουσίας των παθογόνων έναντι των συμβιωτικών οργανισμών στη χοληφόρο οδό αποτελεί σημαντικό στοιχείο για μελλοντικές κλινικές μελέτες.Introduction Preoperative bile duct drainage was first proposed by Whipple. Although animal studies show that bile drainage prior to pancreatic resection improved surgical outcomes, clinical trials in humans have consistently shown no benefit. Preoperative bile stenosis is associated with bacterial infection of the bile and an increased rate of septic complications after pancreatoduodenal resection. Aim The present study aims to study the microbial flora that develops in stents placed with ERCP preoperatively in patients with peripheral neoplasm. Method The data were collected retrospectively from a prospectively recorded database of patients who underwent Pancreatoduodenectomy for peripheral neoplasm at the First Propaideutic Surgery Department of UOA in General Hospital of Hippocratio in the last decade 2010-20. Data from 278 patients were analyzed, 136 of them underwent preoperative stent drainage, 80 of the stents were sent for culture and included in the final sample of the study. Results The study sample consisted of 80 patients, mean age 65 years (IQR 6.0). Women accounted for 51.3% (N = 41), with a BMI of 25.1 kg / m2 (IQR 3.9). All patients underwent pancreatoduodenectomy for peripheral neoplasms. 80 stents were sent for culture, of which 73 (91.3%) were positive for a pathogen while the remaining 7 (8.8%) were sterile. The majority of microorganisms were sensitive to standard antibiotics, with the exception of Klebsiella pneumoniae. The comparison between the group of patients with positive cultures and those with negative cultures did not show statistically significant results (p <0.05), with the exception of the parameters of waiting time in days before surgery and the presence of jaundice. Conclusions The development of different microflora in stents placed endoscopically during preoperative ERCP is a common phenomenon. There is no correlation between positive stent culture and the occurrence of complications, but in comparing the number of germs growing on the stents it was found that in the group of multimicrobial cultures the presence of pancreatic fistula was increased (p = 0.032). Postoperative treatment of septic episodes should take into account the result of cultures and stents. Assessing the presence of pathogens against bile ducts in the bile duct is an important element for future clinical trials

Software development using Openflow Controller (OF Controller) and implementation of routing packets mechanisms

169 σ.Σκοπός της παρούσας διπλωματικής εργασίας είναι η ανάπτυξη και παρουσίαση ενός προγράμματος λογισμικού (εφαρμογής) που εφαρμόζεται σε ένα ελεγκτή δικτύου υπολογιστών, με στόχο την δρομολόγηση των δεδομένων στο δίκτυο με το ελάχιστο ενεργειακό κόστος και την συνεχή εναλλαγή της λειτουργίας (ενεργοποίηση/απενεργοποίηση) των συσκευών του δικτύου. Η επιλογή της κατάλληλης διαδρομής γίνεται αναλόγως του ενεργειακού προφίλ και το φορτίο των συσκευών που δραστηριοποιούνται στο δίκτυο αλλά και των αποφάσεων του διαχειριστή του δικτύου. Για την ανάπτυξη της εφαρμογής αυτής χρησιμοποιείται ένα ερευνητικό πρωτόκολλο επικοινωνιών που ακούει στην ονομασία OpenFlow. Η χρήση του OpenFlow είναι σημαντική, διότι προσφέρει την δυνατότητα απόζευξης του πεδίου δεδομένων από το πεδίο ελέγχου του δικτύου. Έτσι υπάρχει ένα κεντροποιημένο δίκτυο που βασίζει την λειτουργία του σε ένα κεντρικό ελεγκτή, αντί σε επιμέρους συσκευές. Η ανάπτυξη της εφαρμογής γίνεται με την χρήση του πλέον βασικού ελεγκτή του πρωτοκόλλου OpenFlow, του ελεγκτή Beacon. Επιπλέον χρησιμοποιήθηκε το λογισμικό Mininet.Το λογισμικό αυτό αποτελεί έναν εξομοιωτή δικτύου. Έχει τη δυνατότητα να εκτελεί ταυτόχρονα ένα σύνολο από τερματικά, δρομολογητές, μεταγωγείς Ethernet άλλα και των αντίστοιχων συνδέσμων σε ένα ενιαίο Linux Kernel(πυρήνα). Τέλος για την εύρεση της ελάχιστης δυνατής ενεργειακής διαδρομής χρησιμοποιήθηκε το λογισμικό IBM ILOG CPLEX Optimization Studio (συχνά αναφέρεται ως CPLEX). Πρόκειται για ένα πακέτο λογισμικού βελτιστοποίησης που υποστηρίζει γλώσσα προγραμματισμού βελτιστοποίησης (ΟPL) η οποία έχει σχεδιαστεί ειδικά για τη βελτιστοποίηση συνδυαστικών προβλημάτων.The purpose of this thesis is the development and presentation of a software program (application) that is applied to a controller computer network aimed at routing the data to the network with minimum energy costs and continuous operation switch (on / off) on the network. Choosing the right path is depending on the energy profile and the load of the devices operating on the network, but also the decisions of the network administrator. For the development of this application using a research protocol communications hears the name OpenFlow. Using OpenFlow is important because it offers the possibility of decoupling the data field by field control network. So there is a centralized network bases its operation on a centralized controller, rather than individual devices. The development of the application is using the most basic controller protocol OpenFlow, controller Beacon. Additional software used Mininet. To software is a network simulator. It has the capability to simultaneously perform a set of terminals, routers, Ethernet switches and other relevant links on a single Linux Kernel (kernel). Finally finding the minimum possible energy path software used IBM ILOG CPLEX Optimization Studio (often referred to as CPLEX). This is a software package that supports optimization programming language (OPL) that has been designed specifically for combinatorial optimization problems.Ρεντίφης Χριστόφορο

Improving application availability in wireless sensor networks with energy-harvesting capability

We assume a wireless sensor and actuator network with nodes that can harvest energy from the environment, and an application deployed in this network, which is structured as a set of cooperating mobile components that can be placed on any node that provides the required sensor and actuator resources. We propose algorithms that take into account the energy consumption rate of agents as well as energy reserves and harvesting rate of nodes, and decide about the migration of agents in order to improve application availability. Initial evaluation results via simulation show that application availability can be greatly improved compared to having a static application placement. © 2012 IEEE

The Rising Burden of Salmonellosis Caused by Monophasic <i>Salmonella</i> Typhimurium (1,4,[5],12:i:-) in Greece and New Food Vehicles

Monophasic Salmonella typhimurium is of increasing importance worldwide. Here we present the available data regarding monophasic S. typhimurium from 2007 to 2019 in Greece, in order to assess its public health impact. Surveillance data, data on antimicrobial resistance, molecular typing by pulsed-field gel electrophoresis (PFGE), and results of the investigation of monophasic S. typhimurium outbreaks were analyzed. Overall, 403 cases were identified; 329 (81.6%) sporadic and 74 (18.4%) related to two community outbreaks in 2017. A total of 305 isolates from sporadic cases tested for antimicrobial resistance revealed resistance to ampicillin, streptomycin, sulphamethoxazole, and tetracycline (41.3%). Some 23.3% were further resistant to trimethoprim and 5.2% were also resistant to chloramphenicol. Outbreak 1 in 2017 with 37 identified cases was attributed to the consumption of raw milk from a vending machine and isolates were resistant to ampicillin, streptomycin, sulphamethoxazole, tetracycline, and trimethoprim. Outbreak 2 also with 37 cases was attributed to the consumption of pork and isolates were resistant to the five above mentioned antibiotics plus chloramphenicol. The number of human monophasic S. typhimurium isolates is low; however, since 2009, it has been among the five most frequently identified serotypes in Greece. Investigation of the outbreaks revealed that other vehicles apart from pork may be implicated in the occurrence of outbreaks

Impact of space weather on human heart rate during the years 2011–2013

During the last years a possible link between different levels of solar and geomagnetic disturbances and human physiological parameters is suggested by several published studies. In this work the examination of the potential association between heart rate variations and specific space weather activities was performed. A total of 482 individuals treated at Hippocratio General Hospital in Athens, the Cardiology clinics of Nikaia General Hospital in Piraeus and the Heraklion University Hospital in Crete, Greece, were assessed from July 2011 to April 2013. The heart rate of the individuals was recorded by a Holter monitor on a n hourly basis, while the hourly variations of the cosmic ray intensity measured by the Neutron Monitor Station of the Athens University and of the geomagnetic index Dst provided by the Kyoto Observatory were used. The ANalysis Of VAriance (ANOVA) and the Multiple Linear Regression analysis were used for analysis of these data. A statistically significant effect of both cosmic rays and geomagnetic activity on heart rate was observed, which may indicate that changes in space weather could be linked to heart rate variations. © 2017, Springer Science+Business Media B.V

The Rising Burden of Salmonellosis Caused by Monophasic Salmonella Typhimurium (1,4,[5],12:i:-) in Greece and New Food Vehicles

Monophasic Salmonella typhimurium is of increasing importance worldwide. Here we present the available data regarding monophasic S. typhimurium from 2007 to 2019 in Greece, in order to assess its public health impact. Surveillance data, data on antimicrobial resistance, molecular typing by pulsed-field gel electrophoresis (PFGE), and results of the investigation of monophasic S. typhimurium outbreaks were analyzed. Overall, 403 cases were identified; 329 (81.6%) sporadic and 74 (18.4%) related to two community outbreaks in 2017. A total of 305 isolates from sporadic cases tested for antimicrobial resistance revealed resistance to ampicillin, streptomycin, sulphamethoxazole, and tetracycline (41.3%). Some 23.3% were further resistant to trimethoprim and 5.2% were also resistant to chloramphenicol. Outbreak 1 in 2017 with 37 identified cases was attributed to the consumption of raw milk from a vending machine and isolates were resistant to ampicillin, streptomycin, sulphamethoxazole, tetracycline, and trimethoprim. Outbreak 2 also with 37 cases was attributed to the consumption of pork and isolates were resistant to the five above mentioned antibiotics plus chloramphenicol. The number of human monophasic S. typhimurium isolates is low; however, since 2009, it has been among the five most frequently identified serotypes in Greece. Investigation of the outbreaks revealed that other vehicles apart from pork may be implicated in the occurrence of outbreaks

Open versus endovascular repair for extracranial carotid aneurysms

Background: Extracranial carotid artery aneurysms (ECCAs) are rare; however, they are associated with a high risk of stroke and mortality if untreated. In the present review, we compared the major outcomes between open and endovascular repair of ECCAs. Methods: We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for clinical studies reported online up to September 2020 that had evaluated major outcomes after both open and endovascular repair of ECCAs. Eligible studies were required to have evaluated at least the 30-day mortality or stroke and/or transient ischemic attack rates. The quality of the studies was also evaluated. Results: Overall, seven studies (three high quality, two medium quality, and two low quality) with 374 patients and 383 ECCAs were eligible. All the studies had been reported from 2004 to 2020. In total, 220 open repairs were compared with 81 endovascular repairs. The open and endovascular treatments showed similar 30-day mortality rates (4% vs 0%; pooled odds ratio [OR], 2.67; 95% confidence interval [CI], 0.291-24.451) and stroke and transient ischemic attack rates (5.5% vs 1.2%; pooled OR, 1.42; 95% CI, 0.412-4.886). Open repair was associated in six studies with a greater incidence of cranial nerve injury compared with endovascular repair (14.5% vs 0%; OR, 3.98; 95% CI, 1.178-13.471). The hematoma or bleeding rate was also similar between the two methods in six studies (5.2% vs 0%; OR, 1.92; 95% CI, 0.518-7.094). Conclusions: Open and endovascular repair of ECCAs is associated with similarly low early mortality and cerebrovascular event rates, although open repair showed a greater risk of cranial nerve injuries. An endovascular approach could be more appropriate when the aneurysm is located distally or requires extensive dissection. More studies are needed with standardized follow-up durations to evaluate late outcomes

Survey on Grid Resource Allocation Mechanisms

Grid is a distributed high performance computing paradigm that offers various types of resources (like computing, storage, communication) to resource-intensive user tasks. These tasks are scheduled to allocate available Grid resources efficiently to achieve high system throughput and to satisfy user requirements. The task scheduling problem has become more complex with the ever increasing size of Grid systems. Even though selecting an efficient resource allocation strategy for a particular task helps in obtaining a desired level of service, researchers still face difficulties in choosing a suitable technique from a plethora of existing methods in literature. In this paper, we explore and discuss existing resource allocation mechanisms for resource allocation problems employed in Grid systems. The work comprehensively surveys Gird resource allocation mechanisms for different architectures (centralized, distributed, static or dynamic). The paper also compares these resource allocation mechanisms based on their common features such as time complexity, searching mechanism, allocation strategy, optimality, operational environment and objective function they adopt for solving computing- and data-intensive applications. The comprehensive analysis of cutting-edge research in the Grid domain presented in this work provides readers with an understanding of essential concepts of resource allocation mechanisms in Grid systems and helps them identify important and outstanding issues for further investigation. It also helps readers to choose the most appropriate mechanism for a given system/application