DIAGENESIS OF THE MARLY-GYPSUM FORMATIONS, IGOUMENITSA AREA, N.W. GREECE

Η περιοχή της Ηγουμενίτσας στην βορειοδυτική Ελλάδα, συνίσταται από αργιλο-εβαποριτικές αποθέσεις πλούσιες σε οργανικό άνθρακα της Ιονίου ζώνης. Ο σχηματισμός έχει υποστεί διαγενετικές διεργασίες που επηρεάζουν τους ορυκτολογικούς μετασχηματισμούς. Ο σκοπός αυτής της εργασίας είναι η μελέτη της διαγένεσης των ορυκτών και οι πιθανές επιπτώσεις αυτής στη γεωτεχνική συμπεριφορά του σχηματισμού. Τα διαγενετικά ορυκτά του σχηματισμού που αναφέρονται σε αυτή τη εργασία είναι: Α. Αυθιγενή μεικτά αργιλικά ορυκτά σμηκτίτης και μεικτές άργιλοι του σμηκτίτη. Β. Τα δύο χαρακτηριστικά ορυκτά της διαγένεσης των θειικών ορυκτών Ι: Ο βασσανίτης (ημιένυδρος γύψος Ca04.l/2H20) και 2: Ο σελεστίτης (SrSÖ4), που μπορεί να θεωρηθεί ότι είναι ένδειξη βακτηριακής αναγωγής των θειικών, ροής ρευστών και ανακύκλωσης των εβαποριτών. Τα δύο αυτά ορυκτά προέρχονται από τους εβαπορίτες και κυρίως από την διάλυση της γύψου, μέσω της δράσης των πορικών διαλυμάτων, φορτισμένων με ιόντα από την προηγούμενη διάλυση θειικών, αλίτη και ανθρακικών. Γ. Ο νεοσχηματισμός των ανθρακικών ορυκτών αραγωνίτη και δολομίτη, πιθανών λόγω βακτηριακής αναγωγής των θειικών. Όταν με τους εβαπορίτες συνυπάρχουν αργιλικοί σχηματισμοί με διασταλτά αργιλικά ορυκτά και οργανική ύλη, τότε οι διαγενετικές διεργασίες φαίνονται πολύπλοκες και ανταγωνιστικές. Οι διαγενετικές μεταροπές γύψου/ανυδρίτη σχετίζονται με την γεωτεχνική συμπεριφορά του σχηματισμού και μπορεί να προκαλούν καρστικοποίηση. Αυτό μπορεί να δημιουργεί προβλήματα στην κατασκευή δρόμων και σηράγγων στους εβαποριτικους σχηματισμούςThe Igoumenitsa area, in northwestern Greece, is composed of organic-rich clay evaporitic formations, of the Ionian zone. They have undergone diagenetic processes, which effect the mineralogical transformations. The purpose of this paper is the study of the mineralogical diagenesis and the possible implications to the geotechnical behavior of these organic-rich clay evaporitic sedimentary rocks. The diagenetic minerals reported in this study are: A: The authigenic swelling clay minerals, smectite and mixed layers of smectite. B. The two characteristic minerals phases of the sulfate diagenesis: I. Bassanite (semi hydrated gypsum-Ca04.l/2H20) and 2. Celestite (SrS04) that can be considered as an indicator of bacterial sulphate reduction, fluid flow and recycling ofevaporites. The two authigenic minerals have derived from the evaporites, mostly by the dehydration of gypsum and by the action of pore water that is charged with the ions derived from the dissolution of preexistent sulfates, halite and carbonates. C. The neoformation of the carbonate minerals aragonite and dolomite, due to probably bacterial sulfate reduction. When organic-clay rich sediments, are associated to evaporites, the diagenetic processes become more complex and interacted. The diagenetic alterations of the gypsum/anhydrite rocks are related to the geotechnical behavior of the formation and may lead to possible karstiflcation. That may cause problems in roads and tunnels construction on or through these evaporitic serie

Characterization and causes of the building stone decay at the Artemis temple, Brauron, E. Attica, Greece

Στην περιοχή της Βραβρώνας ή Βραώνας στην Α. Αττική σε μικρή απόσταση από τον ομώνυμο κόλπο, δίπλα στις όχθες του Ερασινού ποταμού υπάρχει ο ναός της Αρτέμιδας του 415 π.Χ. Οι δομικοί λίθοι που χρησιμοποιήθηκαν για την κατασκευή του ναού είναι ψαμμίτες και προέρχονται από Νεογενείς ιζηματογενείς αποθέσεις. Ιχνη από τα αρχαία λατομεία σε απόσταση 500μ. από τον ναό είναι ακόμη ορατά. Τα ερείπια του ναού είχαν μείνει θαμένα στην λάσπη του δέλτα του Ερασινού που σχημάτιζε σύστημα ελών και /αμνόθάλασσας, για δεκάδες αιώνων. Κατά τις εργασίες την αναστήλωσης, εκτός από τους θαμένους λίθους χρησιμοποιήθηκε και νέο υλικό από τους σχηματισμούς των αρχαίων λατομείων. Τα αναστηλωμένα τμήματα εμφανίζουν έντονα σημάδια διάβρωσης. Ο σκοπός αυτής της εργασίας είναι η μελέτη των μορφών και των αιτίων της διάβρωσης. Οι διαβρωσιγενείς μορφές οφείλονται σε ενδογενείς και περιβαλλοντολογικούς παράγοντες. Οι κυριότεροι ενδογενείς παράγοντες είναι α) το υψηλό πορώδες, και η κατανομή των πόρων, β) το ασβεστιτικό συνδετικό υλικό του λίθου γ) η ορυκτολογική σύσταση και κυρίως η παρουσία διασταλτών αργιλικών ορυκτών. Οι κυριότεροι περιβαλλοντολογικοί παράγοντες διάβρωσης που συντελούν στην ανακρυστάλλωση του ασβεστίτη και στη κρυστάλλωση αλάτων, είναι α) η παραμονή των δομικών λίθων ενταφιασμένων σε υφάλμυρο περιβάλλον, για αιώνες, β) τα συχνά πλημμυρικά επεισόδια και η πιθανή μόλυνση του ποταμού Ερασινού, γ) η επίδραση της όξινης βροχής και των θαλάσσιων ανέμων και δ) η βιοδιάβρωση. Τα συμπεράσματα αυτής της μελέτης μπορεί να έχουν εφαρμογή και σε άλλα ιστορικά μνημεία σε αντίστοιχα περιβάλλοντα.At Brauron (Vraona or Vravrona) area, E. Attica, near the Brauron bay, by the Erasinos river there is an ancient monument of 415 B.C., dedicated to Artemis. The building material used for the construction of the monument is sandstone originated from Neogene sedimentary deposits. The ancient quarries are located 500m away from the monument and traces of quarring are still visible. Monument ruins had been buried under the mud load curried by Erasinos river for many centuries. During the restoration works of the Temple of Artemis besides the stone found in situ, new material provided by the same formation was as well, used. The restored monument stones display intensive deterioration. The purpose of this paper is to study of the decay forms and investigate the decay causes of the building stone in the monument. The decay forms result from intrinsic (endogenic) and environmental factors. The main endogenic factors of decay of the sandstone used as building material, are: a) the high porosity, and the pore size distribution, b) the calcite cement of the stone c) the mineralogical composition, especially the presence of swelling clay minerals. The main environmental factors of decay that result to the calcite and salt crystallization are a) the burial of the ancient building stones, in the brackish water-mud, for centuries b) the frequent floods and possible pollution of the nearby Erasinos river c) the acid rain and aerosol attack d) the bioteterioration. The conclusions of this case study may have application on other monuments of historical interest, in similar environmen

ON THE OCCURRENCE OF A VOLCANIC ASH LAYER IN THE XYLOKASTRO AREA, NORTH PELOPONNESUS, GREECE: MINERALOGY AND GEOCHEMISTRY

This paper reports, for the first time, the occurrence of an ash layer intercalated within the Plio-Pleistocene lacustrine deposits near Xylokastro area, North Peloponnesus, Greece. Petrographic and geochemical characteristics of the ash layer are the basis of this study. An attempt was made to correlate the present findings to the reported data from other ash deposits. The composition of the ash bed showed a dacitic to rhyolitic calc alkaline suit. The geochemistry of the volcanic ash indicates high crustal contamination of the lava and points to an origin from the northwest part of the Aegean volcanic arc

3D-Printed Modified-Release Tablets: A Review of the Recent Advances

The broad spectrum of applications of three-dimensional printing (3D printing, 3DP) has attracted the attention of researchers working in diverse fields. In pharmaceutics, the main idea behind 3D printing products is to design and develop delivery systems that are suited to an individual’s needs. In this way, the size, appearance, shape, and rate of delivery of a wide array of medicines could be easily adjusted. The aim of this chapter is to provide a compilation of the 3D printing techniques, used for the fabrication of oral drug delivery systems, and review the relevant scientific developments in particular those with modified-release characteristics

Assessing the Long-term Success of Reigate Stone Conservation at Hampton Court Palace and the Tower of London

Reigate stone was extensively used in medieval London and is prone to rapid decay. A variety of different conservation treatments has been applied in the past; in many cases, these have not mitigated on-going decay. This paper presents an overview of wax, limewash, silane and ammonium tartrate treatment at the Tower of London and Hampton Court Palace. Documentary analysis and visual inspection indicate that whilst these methods have provided protection to some stones, no single method has resulted in the protection of all stones. Non-destructive and minimally-destructive testing is used to more closely assess the effects of ammonium tartrate treatment. The results imply that inherent stone mineralogy, past decay pathways and/or present environmental factors are a greater influence on on-going decay than treatment histories

A multi-factorial genetic model for prognostic assessment of high risk melanoma patients receiving adjuvant interferon

Purpose: IFNa was the first cytokine to demonstrate anti-tumor activity in advanced melanoma. Despite the ability of high-dose IFNa reducing relapse and mortality by up to 33%, large majority of patients experience side effects and toxicity which outweigh the benefits. The current study attempts to identify genetic markers likely to be associated with benefit from IFN-a2b treatment and predictive for survival. Experimental design: We tested the association of variants in FOXP3 microsatellites, CTLA4 SNPs and HLA genotype in 284 melanoma patients and their association with prognosis and survival of melanoma patients who received IFNa adjuvant therapy. Results: Univariate survival analysis suggested that patients bearing either the DRB1*15 or HLA-Cw7 allele suffered worse OS while patients bearing either HLA-Cw6 or HLA-B44 enjoyed better OS. DRB1*15 positive patients suffered also worse RFS and conversely HLA-Cw6 positive patients had better RFS. Multivariate analysis revealed that a five-marker genotyping signature was prognostic of OS independent of disease stage. In the multivariate Cox regression model, HLA-B38 (p = 0.021), HLA-C15 (p = 0.025), HLA-C3 (p = 0.014), DRB1*15 (p = 0.005) and CT60*G/G (0.081) were significantly associated with OS with risk ratio of 0.097 (95% CI, 0.013-0.709), 0.387 (95% CI, 0.169-0.889), 0.449 (95% CI, 0.237-0.851), 1.948 (95% CI, 1.221-3.109) and 1.484 (95% IC, 0.953-2.312) respectively. Conclusion: These results suggest that gene polymorphisms relevant to a biological occurrence are more likely to be informative when studied in concert to address potential redundant or conflicting functions that may limit each gene individual contribution. The five markers identified here exemplify this concept though prospective validation in independent cohorts is needed

Assessing hepatitis C virus distribution among vulnerable populations in London using whole genome sequencing: results from the TB-REACH study [version 1; peer review: awaiting peer review]

Background: Injecting drugs substantially increases the risk of hepatitis C virus (HCV) infection and is common in vulnerable population groups, such as the homeless and prisoners. Capturing accurate data on relative genotype distribution within these groups is essential to inform strategies to reduce HCV transmission. The aim of this study was to utilise a next-generation whole-genome sequencing method recently validated by Public Health England, in order to produce near complete HCV genomes. / Methods: In total, 98 HCV positive patients were recruited from homeless hostels and drug treatment services through the National Health Services (NHS) Find and Treat (F&T) Service between May 2011 and June 2013 in London, UK. Samples were sequenced by Next-generation sequencing, with 88 complete HCV genomes constructed by a de novo assembly pipeline. They were analysed phylogenetically for an estimate of their genetic distance. / Results: Of the 88 complete HCV genomes, 50/88 (56.8%) were genotype 1; 32/88 (36.4%) genotype 3; 4/88 (4.5%) genotype 2; and 1/88 (1.1%) for genotypes 4 and 6 each. Subtype 1a had the highest number of samples (51.1%), followed by subtype 3a (35.2%), 1b (5.7%), and 2b (3.4%). Samples collected from drug treatment services had the highest number of genotype 1 (69%); genotypes 4 and 6 were only found from samples collected in homeless shelters. Small clusters of highly related genomic sequences were observed both across and within the vulnerable groups sampled. / Conclusions: Subsequent phylogenetic analysis provides a first indication that there are related HCV sequences amongst the three vulnerable population groups, reflecting their overlapping social behaviours. This study is the first presentation of whole genome HCV sequences from such vulnerable groups in London and paves the way for similar research in the future

PETROLOGICAL CHARACTERS OF THE EARLY CRETACEOUS BOEOTHIAN FLYSCH, (CENTRAL GREECE)

This paper is aimed to study the petrographic characters of the Boeothian Flysch, an Early Cretaceous turbidite deposit which marks the boundary between the External/Internal Hellenides in central-southern Greece, in order to define a preliminary palaeogeographic reconstruction of the Pindos segment of the Alpine Tethys. The Boeothian Flysch is mainly made up by basal conglomerates and arenaceous-pelitic lithofacies, locally interlayered with Calpionellid micrite limestones. This formation is here supposed to belong to the Early Cretaceous flysch family, which marks the contact between the internal and external areas along all the western and central European Alpine Chains for more than 7,000 km, from the Gibraltar Arc to the Balkans via the Calabria-Peloritani Arc. Provenance of these flysch is commonly connected to internal areas, mainly made up by Hercynian crystalline basements and, locally, by ophiolitic complexes. The petrographic data obtained from representative sandstones of the Boeothian Flysch suggest a provenance from internal sources, formed by a Jurassic carbonate platform, metamorphic basements and by ophiolitic complexes, which can be identified with the Pelagonian Terranes (Auct.). An Early Cretaceous uplift and rejuvenation processes, probably related to the late Cretaceous tectogenesis, widely recorded in almost all the central-western Alpine Tethis, affected these internal domains with consequent production of abundant detrital supply in the innermost sector of the Pindos Ocean, whose external margin was bounded by the Parnassos microcontinent

The Effect of Virtual Reality Intervention Programs on the Functionality of Children and Adolescents with Cerebral Palsy. A Systematic Review

Background: Cerebral Palsy (CP) is a neurological disorder of movement and posture. Recent studies have shown that Virtual Reality (VR) is a useful and low-cost tool used in treating children and adolescents with cerebral palsy. Nevertheless, there is no substantial evidence supporting that VR therapy can help CP patients, not only as the primary treatment, but as a supplement. Objectives: The present systematic review aimed to investigate the effectiveness of VR intervention programs on the functional capacity of children and adolescents with CP, according to the International Classification of Functioning, Disability and Health (ICF). Methods: A systematic online search was conducted in PubMed, Scopus, and PEDro databases, as well as in the Google Scholar search engine, from inception till September 2022. The methodological quality of included studies was rated with the PEDro scale. Results: Twenty-two randomized-controlled trials were eligible for inclusion. The results indicated that there was a significant improvement after the implementation, of interventional VR programs, in balance and visual perception, while the results were controversial for muscle strength, coordination, gross motor function, gait, upper limb function, independence in activities of Daily Life Activities and participation. Conclusion: Significant balance and visual perception improvements may result from VR programs applied in children and adolescents with CP. Important factors that may influence the results are the functional level of the participants, the sample size, the context in which the therapeutic intervention is carried out (rehabilitation center, home), and the conventional treatments that the VR intervention programs are compared against