253 research outputs found
Airway pressure and outcome of out-of-hospital cardiac arrest: A prospective observational study
No full textAim To assess the usefulness of airway pressure as predictor of return of spontaneous circulation (ROSC), as well as to investigate the optimized ventilation compression strategy during cardiopulmonary resuscitation (CPR). Methods In this prospective observational study, 300 out-of-hospital cardiac arrest victims were intubated and resuscitated with the use of a ventilator. Mean airway pressure (mPaw) was measured at pre-defined phases of CPR. Results A significant difference in mPaw was observed between survivors and non-survivors after the onset of the third minute of CPR. An mPaw value of 42.5 mbar during CPR had specificity and sensitivity of 0.788 and 0.804, respectively, for ROSC (AUC = 0.668, p = 0.047). During CPR, we found statistically significant differences in mPaw at phases zero (F = 4.526, p = 0.002), two (F = 4.506, p = 0.002), four (F = 8.187, p < 0.0001), five (F = 2.871, p = 0.024), and six (F = 5.364, p < 0.0001). Conclusion Mean airway pressure was higher in survivors. A value of 42.5 mbar was associated with ROSC
Data Set of PLOS Computational Paper PCOMPBIOL-D-18-02181R1
No full textFigures Data of PLOS Computational paper:Modeling of the axon plasma membrane structure and its effects on protein diffusionAuthors: Yihao Zhang, Anastasios V. Tzingounis, and George LykotrafitisCorresponding Author: George Lykotrafitis, Ph.D.University of ConnecticutStorss, CT UNITED STATES</div
The state of modern Greek language as spoken in Victoria
No full textDeposited with permission of the author. © 1986 Dr. Anastasios TamisThis thesis reports a sociolinguistic study, carried out between 1981 and 1984, of the state of the Modern Greek (MG) language in Australia, as spoken by native-speaking first-generation Greek immigrants in Victoria. Particular emphasis is given to the analysis of those characteristics of the linguistic behaviour of these Greek Australians which can be attributed to the contact with English and to other environmental, social and linguistic influence. (For complete abstract open document
The correlation of inflammatory markers and insulin resistance indexes with the outcome of an acute coronary syndrome in known diabetes, newly diagnosed diabetes patients, IGT's and normoglycemics
No full textAim: The glucose metabolism disorder is frequent in patients who are admitted after an Acute Coronary Syndrome (ACS). The aim of this study is to examine the correlation of ACS with the markers of insulin resistance and inflammatory markers in known diabetes patients, newly diagnosed diabetes patients, patients with impaired glucose tolerance (IGT) and normoglycaemic patients. Material and Methods: 536 patients who were hospitalized at the Cardiology Department of Tzanio General Hospital of Piraeus from April 2007 to March 2009 were included in the study. All patients undewent a clinical laboratory testing. Fastubg glucose and insulin were recorded by morning blood testing during their first day of hospitalization in order to measure insulin-resistance indexes. All non diabetic patients went under an oral glucose tolerance test (OGTT) one month after discharge. Study’s end-points were death, a new ACS, arrythmias and acute pulmonary oedema of cardiological origin. End-points were registered during hospitalization and 12 months after the ACS. Results: 199 (37,12%) patients were norcmoglycemic while 168 (31,34%) were known diabetics, 59 (11%) newly diagnosed diabetic patients and 110 (20,52%) were IGT patients. 255 (47.6%) patients were hospitalized for acute myocardial infarction with ST elevation (STEMI), 180 (33,6%) patients for acute myocardial infarction without ST elevation (NSTEMI) and 101 (18,8%) patients for unstable angina. There was a statistically significant correlation of the hs-CRP with the outcome during hospitalization (p=0,004) for all patients. hs-CRP (p=0,001) and HOMA index (p=0,009) were significantly correlated with the appearance of a major cardiovascular event during hospitalization for all patients. Complications during the first 12 months after an ACS were significantly correlated with the hs-CRP, HOMA and QUICKI indexes in a univariate and multivariate analysis. The hs-CRP, HOMA and QUICKI indexes are indepedently associated with the 12 months outcome for all patients and for each group separately.Conclusions: hs-CRP is the inflammation marker which is correlated with the appearance of complications during hospitalization and 12 months after an ACS regardless of patients’ glycaemic profile, while HOMA and QUICKI indexes are correlated with the appearance of major cardiovascular events during hospitalization as well as the 12-month follow-up period. The combination of these indexes with hs-CR significantly improves the latter’s prognostic model in particular regarding major cardiovascular events.2.Σκοπός: Ο επιπολασμός της διαταραχής του μεταβολισμού της γλυκόζης είναι υψηλός μεταξύ των ατόμων που εισέρχονται για νοσηλεία μετά από Οξύ Στεφανιαίο Σύνδρομο. Σκοπός της παρούσας μελέτης είναι η διερεύνηση της συσχέτισης της έκβασης των Οξέων Στεφανιαίων Συνδρόμων με τους δείκτες ινσουλινοαντίστασης και τους δείκτες φλεγμονής σε γνωστούς διαβητικούς, σε νεοδιαγνωσμένους διαβητικούς, σε ασθενείς με παθολογική ανοχή γλυκόζης (IGT) και σε νορμογλυκαιμικούς ασθενείς.3.Υλικό και Μέθοδος: Στη μελέτη συμπεριληφθήκαν 536 ασθενείς οι οποίοι νοσηλεύθηκαν στην Καρδιολογική Κλινική του Γ. Ν. Π «Τζάνειο» από τον Απρίλιο του 2007 έως τον Μάρτιο του 2009 για Οξύ Στεφανιαίο Σύνδρομο. Οι ασθενείς υποβλήθηκαν σε κλινικοεργαστηριακό έλεγχο. Έγινε μέτρηση της γλυκόζης νηστείας και της ινσουλίνης με πρωινή αιμοληψία κατά την πρώτη ημέρα νοσηλείας των ασθενών για τον υπολογισμό των δεικτών ινσουλινοαντίστασης. Οι μη διαβητικοί ασθενείς υποβλήθηκαν σε δοκιμασία ανοχής γλυκόζης (OGTT) ένα μήνα μετά την έξοδο από το νοσοκομείο. Ως τελικά σημεία ορίστηκαν ο θάνατος, νέο επεισόδιο οξέος στεφανιαίου συνδρόμου, οι αρρυθμίες και το Οξύ Πνευμονικό Οίδημα καρδιακής αιτιολογίας. Έγινε καταγραφή αυτών κατά την νοσηλεία και κατά τους πρώτους 12 μήνες μετά το οξύ στεφανιαίο σύνδρομο. 4.Αποτελέσματα: Από τους 536 ασθενείς της μελέτης νορμογλυκαιμικοί ήταν οι 199 (37,12%), 168 (31,34%) ήταν γνωστοί διαβητικοί, 59 (11%) νεοδιαγνωσμένοι διαβητικοί και 110 (20,52%) ήταν οι ασθενείς με διαταραχή στην ανοχή της γλυκόζης (IGT). Με διάγνωση οξύ έμφραγμα του μυοκαρδίου με ανάσπαση του διαστήματος ST νοσηλεύθηκαν 255 (47,6%) ασθενείς, με οξύ έμφραγμα του μυοκαρδίου χωρίς ανάσπαση του διαστήματος ST 180 (33,6%) και με διάγνωση ασταθή στηθάγχη 101(18,8%) ασθενείς. Από τους υπό εξέταση δείκτες στατιστικά σημαντική η συσχέτιση της υψηλής ευαισθησίας CRP (hs-CRP) (p=0,004), με την έκβαση κατά την νοσηλεία για το σύνολο των ασθενών. Η hs-CRP (p=0,001) και ο δείκτης HOMA (p=0,009) παρουσίασαν στατιστικά σημαντική συσχέτιση και με την εμφάνιση μείζονων καρδιαγγειακών συμβαμάτων κατά τη νοσηλεία για το σύνολο των ασθενών. Η εμφάνιση επιπλοκών κατά τους πρώτους 12 μήνες μετά από οξύ στεφανιαίο σύνδρομο παρουσιάζει συσχέτιση με την hs-CRP και τους δείκτες ΗΟΜΑ και QUICKI τόσο σε μονοπαραγοντική όσο και σε πολυπαραγοντική ανάλυση. Την ανεξάρτητη συσχέτιση τους με την εμφάνιση μείζονων καρδιαγγειακών συμβαμάτων κατά τους πρώτους 12 μήνες, διατηρούν η hs-CRP και οι δείκτες HOMA και QUICKI τόσο για το σύνολο των ασθενών όσο και για τις επιμέρους ομάδες αυτών. 5.Συμπεράσματα: Η hs-CRP αποτελεί τον δείκτη φλεγμονής ο οποίος συνδέεται με την εμφάνιση επιπλοκών τόσο κατά τη νοσηλεία όσο και κατά τους 12 μήνες μετά από οξύ στεφανιαίο σύνδρομο ανεξάρτητα από το γλυκαιμικό προφίλ των ασθενών, ενώ οι δείκτες ινσουλινοαντίστασης HOMA και QUICKI σχετίζονται με την εμφάνιση μείζονων καρδιαγγειακών συμβαμάτων τόσο κατά την νοσηλεία όσο κατά τους 12 μήνες της παρακολούθησης. Η προσθήκη τους δε στην hs-CRP βελτιώνει το προγνωστικό μοντέλο της hs-CRP ειδικά για τα μείζονα καρδιαγγειακά συμβάματα
New historical evidence for Anastasios Emm. Papas
No full textNo AbstractThe author’s attention has been drawn to the existence of this historicalevidence in the National Archives of Vienna, by his friend the writer EteoclesGregoriadis together with the numbers of the relevant files. Most of the documents were written in the old German script. Thus the author asked for the help of his friend and former colleague at the University of Thessaloniki and director of the Goethe Institute, Graf Kurt v. Posadowsky, for reading andstudying those documents. Without his help this study would have been impossible. This new evidence concerns the sojourn of Anastasios Papas·—son of Emmanuel Papas, leading figure of the Greek Revolution—in Austria andGermany between the 3rd January and 11th March 1822. There is informationabout his short imprisonment in Trieste, after his arival from Vienna. He then visits various towns in Germany and after negotiations with the Philhellene professor Fr. Thiersch in Munich, he purchases large quantities of ammunition to be despatched to Greece. He finally arrives in Greece early in 1824, and takes part—together with his three brothers who were already fighting—in the struggle for the liberation of the common great fartheland
Measurement of damage growth in ultrasonic spot welded joint
No full textUltrasonic spot welding is a joining technique for thermoplastic composites with great potential regarding processing speed and cost. To investigate the damage tolerance and possible inherent damage arresting behavior of multi-spot welded joints, a technique is necessary to measure damage growth in the joints under cyclic loading. Visual inspection is not possible because the damage is not located on the outside surface and conventional techniques such as C-scan are not practical during a fatigue test because the specimen would have to be removed from the setup. This paper details a methodology for quantifying damage growth rates in singlespot welded joints using surface strain measurements made by Digital Image Correlation. This represents the first step towards developing a methodology for quantifying damage progression behavior in complex multi-spot welded joints.Structural Integrity & CompositesAerospace Structures & Computational Mechanic
Development and characterization of hybrid thin-ply composite materials
No full textThin-ply composites are recognized as a key solution for the manufacturing of high-performance composite structures due to the unique mechanical properties and the increased design versatility that they offer. They are obtained with state-of-the-art fiber spreading methods where high-count (6-24K filaments) tows of technical fibers (carbon, glass) are thinned by spreading into flat unidirectional tapes which are then combined with a polymer matrix to create pre-impregnated (prepregs) tapes of reduced thickness. In recent years, the industrialization of fiber spreading and impregnation processes enabled the large-scale production of homogenous thin-ply prepregs with thicknesses down to about 15μm per ply, which attracted the interest of the research community. However, the high production cost due to the complexity of the manufacturing methods and the inherent brittleness of thin-ply composites limit their wider adoption by the composites industry[1]. Fiber hybridization (i.e combining at least two types of fibers in a common matrix) is emerging as a promising approach for alleviating these drawbacks towards laminates with balanced characteristics in terms of mechanical properties and cost-efficiency. Currently, most studies on thin-ply hybrids employ simple interlayer (ply-by-ply) configurations mainly due to difficulties in manufacturing of more complex hybrid architectures[2]. However, simulation tools predict that notable improvements can be obtained from more complex intralayer (tow-by-tow) and intrayarn (fiber-by-fiber) hybrid architectures[3]. This work focuses on the study of existing fiber spreading methodologies, the development of equipment, and the optimization of composite processing at North Thin Ply Technology (NTPT) Renens, Switzerland, that allowed the manufacturing of hybrid composites with a high degree of fiber dispersion and controlled microstructure. Hybrid prepregs were produced by combining various ratios of dissimilar fibers following different processing routes. Composite laminates were manufactured and a versatile microstructural analysis tool was developed that enabled correlations between the manufacturing route, the resulting microstructural features describing the degree of co-dispersion, and the mechanical performance of the final part. Acknowledgments The research leading to these results has been performed within the framework of the HyFiSyn project and has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 765881. Delamination growth in fibre reinforced polymer composites is generally evaluated with experiments that have been standardized for quasi-static load conditions. These tests characterize unidirectional delamination growth in mode I (DCB), mode II (ELS or ENF) of mixed mode conditions (MMB). However, little attention is paid in literature to the applicability of these tests to in-service delamination problems that are generally characterized by planar delamination growth. In this study, the relation between planar delamination growth, induced by transverse quasi-static indentation loading, and these unidirectional delamination tests was investigated. To that aim, prior planar delamination growth tests reported in literature, performed at EPFL, were analysed to identify up to what extent this planar growth could be correlated to the concepts of strain energy release and strain energy density. Once this appeared to successful, an experimental setup was designed to measure the delamination boundary during the transverse indentation loading of planar delamination specimens made of nontransparent carbon fibre reinforced polymer composites. With that set-up, quasi-static and fatigue planar delamination growth experiments were performed, and delamination contours could be successfully captured. While the quasi-static tests revealed limited growth, evaluation with numerical simulations revealed that the indentation force required to extend the delamination quasi-statically would cause damage to the specimen. This is attributed to the increasing length of the delamination contour when delaminations expand, which is not the case with standard unidirectional specimen. With the fatigue tests, however, delamination growth was achieved, but interestingly enough two phases were observed; first the delamination propagated in a planar fashion, while at some point in time work did not exceed an apparent threshold. Instead of no growth, however, the delamination still increased but then in a transverse manner. What makes this study of particular interest, is that the strain energy density as criterion could capture the strain energy offered (work) along the entire delamination contour, while the strain energy release rate described the resistance to delamination growth. This latter observation is in agreement with the original concept employed by Griffith when he formulated the basis of linear elastic fracture mechanics. This presentation present the experiments performed, the analysis of results, and will conclude with a proposal how to relate standard unidirectional tests to planar growth, considering that these standard tests contain little to no information on transverse phenomena with respect to strain energy density (work) and strain energy release (dissipation).Aerospace Manufacturing Technologie
The role of matrix boundary in the microstructure of unidirectional composites
No full textFinding new ways to evaluate the variability of microstructures, and its effect on macroscopic properties such as permeability and mechanical performance [1,2] is of increasing interest in the composite field. The variability of microstructural features at a three-dimensional level is not fully understood and its effect on macroscale properties is not well established, and mostly analyzed at a phenomenological level [3]. We introduced in recent work a method based on X-ray Computed Tomography for the threedimensional reconstruction of the fibrous microstructure of unidirectional tapes at a single fibre resolution [4]. A schematic of the workflow is represented in Figure 1. Three descriptors are introduced in the work to describe increasing level of complexity in the microstructural organization, from a single fiber path level with differential tortuosity, to group behavior with collective motion, to fibre network connectivity with length of contact. These descriptors and their interdependence highlight local effects like edge-core segregation in microstructural characteristics. However, in order to achieve a more complete definition of the unidirectional tape domain, understanding of matrix-based features and its interrelation with fiber architecture descriptors is needed. In this work, we expand the methodology of Gomarasca et al. [4], to account for matrix-based phenomena such as tape boundary variability, and void formation and morphology. This will be showcased on a unidirectional composite tape including both fiber-based and matrix-based analysis. These methods enable advanced characterization and modelling of microstructural formation and evolution during composite manufacturing.Aerospace Manufacturing TechnologiesAerospace Structures & Computational Mechanic
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