Abrasion resistance of fibre reinforced concrete floors

This thesis focuses on the investigation of the abrasion resistance of fibre reinforced concrete floors at both the macro and micro levels. A literature review of the available literature concerning subjects allied to the current project is included. This highlights themes relevant to wear mechanisms and the factors influencing it: factors that affect the abrasion resistance of concrete and several test methods for assessing it; and the historical development of fibres and the properties of different fibre types and their influence on concrete. Three accelerated abrasion testers were compared and critically discussed for their suitability for assessing the abrasion resistance of concrete floors. Based on the experimental findings one accelerated abrasion apparatus was selected as more appropriate to be used for carrying out the main investigations. The laboratory programme that followed was undertaken to investigate the influence of various material and construction factors on abrasion resistance. These included mix variations (w/c ratio), fibre reinforcement, geometry, type and volume, curing method and superplasticizing agents. The results clearly show that these factors significantly affected abrasion resistance and several mechanisms were presumed to explain and better understand these observations. To verify and understand these mechanisms that are accountable for the breakdown of concrete slabs, the same concrete specimens that were used for the macro-study, were also subjected to microstructutural investigations using techniques such as Microhardness examination, Mercury intrusion porosimetry and Petrographic examination. It has been found that the abrasion resistance of concrete is primarily dependent on the microstructure and porosity of the concrete nearest to the surface. The feasibility of predicting the abrasion resistance of fibre reinforced concrete floors by indirect and non-destructive methods was investigated using five methods that have frequently been used for assessing the quality of concrete. They included the initial surface absorption test, the impact test, ball cratering, the scratch test and the base hardness test. The impact resistance (BRE screed tester) and scratch resistance (Base hardness tester) were found to be the most sensitive to factors affecting abrasion resistance and hence are considered to be the most appropriate testing techniques. In an attempt to develop an appropriate method for assessing the abrasion resistance of heavy-duty industrial concrete floors, it was found that the presence of curing/sealing compound on the concrete surface at the time of accelerated abrasion testing produces inappropriate results. A preliminary investigation in the direction of modifying the Aston accelerated abrasion tester has been carried out and a more aggressive head has been developed and is pending future research towards standardisation

Socio- Demographic, Clinical and Lifestyle Determinants of Low Response Rate on a Self- Reported Psychological Multi-Item Instrument Assessing the Adults’ Hostility and its Direction: ATTICA Epidemiological Study (2002-2012)

Background: Missing data constitutes a common phenomenon, especially, in questionnaire-based, population surveys or epidemiological studies, with the statistical power, the efficiency and the validity of the conducted analyses being significantly affected by the missing information. The aim of the present work was to investigate the socio-demographic, lifestyle and clinical determinants of low response rate in a self- rating multi-item scale, estimating the individuals’ hostility and direction of hostility.Methods: 3042 apparently healthy volunteers residing in the Athens metropolitan area participated in the ATTICA epidemiological study [1514 (49.8%) were men [46 years old (SD= 13 years)] and 1528 (50.2%) were women [45 years old (SD= 14 years)]]. Hostility and Direction of Hostility was assessed with the Hostility and Direction of Hostility (HDHQ) scale. Binary logistic regression with backward model selection was used in order to identify the key demographic, clinical and lifestyle determinants of higher non-response rate in the HDHQ scale.Results: The vast majority of the participants (87.0%) had missing information in the HDHQ scale. Older age, lower educational level, poorer health status and unhealthy dietary habits, were found to be significant determinants of high nonresponse rate, while female participants were found to be more likely to have missing data in the items of the HDHQ scale.Conclusions: The present work augments prior evidence that higher non-response to health surveys is significantly affected by responders’ background characteristics, while it gives rise to research towards unrevealed paths behind this claim

Μελέτη του προφίλ της ανεξάρτητης κλινικής έρευνας στην Ογκολογία μέσω της ανασκόπησης των χαρακτηριστικών των μη-εμπορικών δοκιμών στα πλαίσια του EORTC κατά τη δεκαετία 2009-2019.

Η ανεξάρτητη κλινική έρευνα αντιπροσωπεύει σημαντικό και ουσιώδες μέρος της κλινικής έρευνας στην ογκολογία. Ο σκοπός της εργασίας είναι να παρέχει ένα στιγμιότυπο των μη-εμπορικών δοκιμών στην ογκολογία στο ευρωπαϊκό περιβάλλον την τελευταία δεκαετία. Έγινε αναδρομική συλλογή των δεδομένων από 115 μη-εμπορικές παρεμβατικές κλινικές δοκιμές με χορηγό τον EORTC, που δημοσιεύθηκαν κατά τη χρονική περίοδο 2009-2019. Το 56.5% των δοκιμών ήταν φάσης ΙΙΙ και 79.1% ήταν τυχαιοποιημένες. Σε 109 δοκιμές υπήρχαν αναλυτικά στοιχεία των παρόχων χρηματοδότησης. Η συνολική επιβίωση ήταν το συχνότερο πρωτεύον καταληκτικό σημείο. Περισσότερες από τις μισές δοκιμές δεν επιβεβαίωσαν την ερευνητική τους υπόθεση. Μόνο 28 δοκιμές περιελάμβαναν μετρήσεις της ποιότητας ζωής. Παρατηρήθηκε πρόωρη διακοπή στο 21,1% των δοκιμών. Οι κύριοι λόγοι για την πρόωρη διακοπή ήταν: χαμηλός ρυθμός εισαγωγής ασθενών (50%), ματαιοπονία-έλλειψη επαρκούς αποτελεσματικότητας (29,2%). Η πληροφορία της έντυπης συγκατάθεσης μετά από ενημέρωση ήταν πάντα διαθέσιμη. Μέγεθος δείγματος άνω των 500 ασθενών παρατηρήθηκε στο 32,2% των δοκιμών. Οι περισσότερες δοκιμές σχεδιάστηκαν για να επιτύχουν τουλάχιστον 80% στατιστική ισχύ. Πενήντα πέντε δοκιμές (48,2%) δημοσιεύθηκαν σε περιοδικά με συντελεστή απήχησης υψηλότερο από 10. Το 65,2% των δοκιμών δημοσιεύθηκαν μεταξύ 2009 και 2013 και το 34,8% μεταξύ 2014 και 2019, τα χαρακτηριστικά των δοκιμών των δύο περιόδων δεν διέφεραν σημα-ντικά. Η ανεξάρτητη κλινική έρευνα προσπαθεί να απαντήσει σε ερωτήματα που απασχολούν την επιστημονική κοινότητα, τα οποία μπορεί να μην ενδιαφέρουν τους εμπορικούς χορηγούς. Την ώρα που οι αυξανόμενες γραφειοκρατικές απαιτήσεις και τα περιορισμένα κεφάλαια δρουν ως τροχοπέδη, οργανισμοί της εμβέλειας του EORTC συμβάλλουν αποφασιστικά στην ανάπτυξή της.Independent clinical research constitutes an important and substantial part of clinical research activities in oncology. The aim of this thesis is to profile the landscape of Investigator-Inititated Trials (IIT) in oncology taking place in Europe over the last decade. A retrospective collection of data of 115 EORTC-sponsored prospective IITs published from 2009 to 2019 was the data material under study. Most of the trials were phase III studies. Of all trials studied, 79.1% were randomized. In 109 trials, detailed data on funding were available. The most commonly used primary endpoint was Overall Survival (28.1%). More than 50% of trials failed to meet their primary endpoint of the hypothesis tested. Quality of life parameters were studied in 20 trials. Premature trial interrup-tion was observed in 24 trials (21.2%), the main reasons being low patient accrual (50%) and futility (29.2%). An informed consent form was available in all trials. 37 trials (32.2%) involved more than 500 patients. Among statistical characteristics, a 80% power or higher was employed in the vast majority of trials. In the 2009-2013 interval, 75 IITs had been published, while in the 40 in the 2014-2019 interval. Fifty five IITs resulted in publications in peer reviewed jour-nals with an Impact Factor>10. Trials published in the two time intervals ( 2009-2013 vs 2014-2019) did not differ substantially in their characteristics. Independent clinical research is essential for addressing questions that are of relevance to the scientific community and patients, topics that may fail to incentivize commercial sponsors. At a context of increasing bureaucratic burden and limited funds, independent research organizations such as EORTC need to adapt in order to contribute further to academic oncological research

Ομιλητική ακοομετρία με ψευδολέξεις(non-sense words)- Εγκυρότητα και αξιοπιστία σε ασθενείς με νευροαισθητήρια βαρηκοΐα: Ανασκόπηση βιβλιογραφίας

Εισαγωγή: Για να μπορέσει να δημιουργηθεί ένα τεστ, το οποίο να μετράει την ικανότητα ενός ατόμου να αναγνωρίζει ήχους της ομιλίας, είναι απαραίτητο να υπάρχει μια ακριβής μέθοδος μέτρησης αυτής της ικανότητας. Συγκεκριμένα βασικά κριτήρια θεωρήθηκαν ουσιώδη από διάφορους ερευνητές, σαν οδηγός στην επιλογή των στοιχείων του ομιλητικού υλικού για τα τεστ ομιλητικής ακοομετρίας. Τα ενδεδειγμένα τεστ κατανόησης της ομιλίας πρέπει να είναι ευαίσθητα, έγκυρα, αξιόπιστα και εφαρμόσιμα. Μεθοδολογία: Πραγματοποιήθηκε συστηματική ανασκόπηση της δημοσιευμένης αρθρογραφίας μέχρι τον Αύγουστο 2019 στις βάσεις δεδομένων Pubmed και Google Scholar με τη χρήση κατάλληλων όρων. Αποτελέσματα: Μετά από εκτεταμένη αναζήτηση και μελέτη της υπάρχουσας αρθρογραφίας επιλέχθηκαν δώδεκα άρθρα, τα οποία περιελάμβαναν τεστ ομιλητικής ακοομετρίας με ψευδολέξεις. Πέντε εξ ̓αυτών χορήγησαν λίστες ψευδολέξεων μόνο σε άτομα με φυσιολογική ακοή, δύο μόνο σε ασθενείς με νευροαισθητήρια βαρηκοΐα, ενώ τέσσερα και στις δύο ομάδες συμμετεχόντων. Μία μελέτη δεν χορήγησε τις ψευδολέξεις σε συμμετέχοντες. Συζήτηση: Στην πλειοψηφία τους τα τεστ, τα οποία μελετήθηκαν είναι έγκυρα και ευαίσθητα, παρότι δεν πληρούν όλα το κριτήριο της φωνητικής ή φωνημικής ισορροπίας. Συμπεράσματα: Η παρούσα ανασκόπηση μπορεί να αποτελέσει το κίνητρο για την διερεύνηση της επίδρασης της φωνητικής ή φωνημικής ισορροπίας των λιστών ψευδολέξεων για την ελληνική γλώσσα, ώστε να αναπτυχθούν έγκυρα και αξιόπιστα εργαλεία εξέτασης ομιλητικής ακοομετρίας για ασθενείς με νευροαισθητήρια βαρηκοΐα. Λέξεις Κλειδιά: nonsense words, ομιλητική ακοομετρία με ψευδολέξεις, φωνητική ισορροπία, φωνημική ισορροπία, νευροαισθητήρια βαρηκοΐαIntroduction: There must be an accurate method of measurement in order to create a valid test that quantifies a person's ability to recognize speech sound. This thesis describes the need for a speech comprehension test that addresses in a sensitive, valid, reliable and applicable way each person’s ability. Specific key criteria were considered essential by various researchers as a guide in the selection of the spoken material for the audiometry tests. Methodology: A systematic review of published articles has been conducted, in Pubmed and Google Scholar databases, using appropriate terms. Results: Twelve articles have been selected, through an extensive list, and were consisted of speech audiometry tests with nonsense words. Five out of them gave nonsense word lists only to people with normal hearing, two only to patients with sensorineural hearing loss, and four in both groups of participants. One study failed to provide nonsense words to participants. Discussion: Most of the tests are valid and sensitive, although they do not meet the criteria of a phonetic or phonemic balance. Conclusions: This review may trigger a further investigation regarding the impact that the phonetic or phonemic balance of the nonsense word lists may have on the Greek language, in order to develop valid and reliable speech audiometry tools for patients with sensorineural hearing loss. Key Words: nonsense words, speech audiometry with nonsense words, phonetic balance, phonemic balance, sensorineural hearing los

A Novel Hantavirus of the European Mole, Bruges Virus, Is Involved in Frequent Nova Virus Coinfections

Hantaviruses are zoonotic viruses with a complex evolutionary history of virus–host coevolution and cross-species transmission. Although hantaviruses have a broad reservoir host range, virus–host relationships were previously thought to be strict, with a single virus species infecting a single host species. Here, we describe Bruges virus, a novel hantavirus harbored by the European mole (Talpa europaea), which is the well-known host of Nova virus. Phylogenetic analyses of all three genomic segments showed tree topology inconsistencies, suggesting that Bruges virus has emerged from cross-species transmission and ancient reassortment events. A high number of coinfections with Bruges and Nova viruses was detected, but no evidence was found for reassortment between these two hantaviruses. These findings highlight the complexity of hantavirus evolution and the importance of further investigation of hantavirus–reservoir relationships

Extramedullary myeloma in an HIV-seropositive subject. Literature review and report of an unusual case

Myeloma is characterized by monoclonal bone marrow plasmacytosis, the presence of M-protein in serum and/or in urine and osteolytic bone lesions. HIV-seropositive subjects with myeloma are younger at the time of diagnosis of the tumour and usually the myeloma has a more aggressive clinical course than it does in HIV-seronegative subjects

Spatial and temporal heterogeneity in human mobility patterns in Holocene Southwest Asia and the East Mediterranean

We present a spatiotemporal picture of human genetic diversity in Anatolia, Iran, Levant, South Caucasus, and the Aegean, a broad region that experienced the earliest Neolithic transition and the emergence of complex hierarchical societies. Combining 35 new ancient shotgun genomes with 382 ancient and 23 present-day published genomes, we found that genetic diversity within each region steadily increased through the Holocene. We further observed that the inferred sources of gene flow shifted in time. In the first half of the Holocene, Southwest Asian and the East Mediterranean populations homogenized among themselves. Starting with the Bronze Age, however, regional populations diverged from each other, most likely driven by gene flow from external sources, which we term “the expanding mobility model.” Interestingly, this increase in inter-regional divergence can be captured by outgroup-f$_3$-based genetic distances, but not by the commonly used F$_{ST}$ statistic, due to the sensitivity of F$_{ST}$, but not outgroup-f$_3$, to within-population diversity. Finally, we report a temporal trend of increasing male bias in admixture events through the Holocene

The statistical analysis plan for the unification of treatments and interventions for tinnitus patients randomized clinical trial (UNITI-RCT)

Background Tinnitus is a leading cause of disease burden globally. Several therapeutic strategies are recommended in guidelines for the reduction of tinnitus distress; however, little is known about the potentially increased effectiveness of a combination of treatments and personalized treatments for each tinnitus patient. Methods Within the Unification of Treatments and Interventions for Tinnitus Patients project, a multicenter, randomized clinical trial is conducted with the aim to compare the effectiveness of single treatments and combined treatments on tinnitus distress (UNITI-RCT). Five different tinnitus centers across Europe aim to treat chronic tinnitus patients with either cognitive behavioral therapy, sound therapy, structured counseling, or hearing aids alone, or with a combination of two of these treatments, resulting in four treatment arms with single treatment and six treatment arms with combinational treatment. This statistical analysis plan describes the statistical methods to be deployed in the UNITI-RCT. Discussion The UNITI-RCT trial will provide important evidence about whether a combination of treatments is superior to a single treatment alone in the management of chronic tinnitus patients. This pre-specified statistical analysis plan details the methodology for the analysis of the UNITI trial results. Trial registration ClinicalTrials.gov NCT04663828. The trial is ongoing. Date of registration: December 11, 2020. All patients that finished their treatment before 19 December 2022 are included in the main RCT analysis