Development of a human-structure dynamic interaction model for human sway for use in permanent grandstand design

This paper details a first attempt to develop a simple human-structure dynamic interaction (HSDI) model for vibration serviceability design of permanent grandstands subject to crowd sway. To date, extensive research has been conducted on vertical crowd-induced vibrations to understand interaction mechanisms and enable engineers to account for them. Similar mechanisms have not yet been fully understood or researched in the lateral plane. This, alongside the limited, verified measured response data has led to incomplete design assessment methods. In this work, an effective two-degree-of-freedom spring-mass-damper-actuator system is developed to represent co-ordinated spectators swaying laterally in the side-to-side direction on a real grandstand. The dynamic properties attributed in the constituents of the model are determined by curve fitting of laboratory-scale human sway data and the modal analysis of the grandstand’s finite element model. The comparison of the modelling output against existing serviceability criteria approaches illustrates potential conservatism in current practice. Namely, when the maximum responses and forces were examined as part of the integrated dynamic system a notable drop-out effect was observed. Although further research is required to validate and calibrate the proposed simple human-structure sway model for individuals and crowds, the observations qualitatively determine the significance of explicitly considering human-structure interaction in the design and assessment of permanent grandstands. Such effects may lead to construction cost savings in addition to unwanted limitations on architecture, hospitality areas and spectator circulation

Quantitative assessment of the variability in chemical profiles from source apportionment analysis of PM10 and PM2.5 at different sites within a large metropolitan area

The study aims to assess the differences between the chemical profiles of the major anthropogenic and natural PM sources in two areas with different levels of urbanization and traffic density within the same urban agglomeration. A traffic site and an urban background site in the Athens Metropolitan Area have been selected for this comparison. For both sites, eight sources were identified, with seven of them being common for the two sites (Mineral Dust, non-Exhaust Emissions, Exhaust Emissions, Heavy Oil Combustion, Sulfates & Organics, Sea Salt and Biomass Burning) and one, site-specific (Nitrates for the traffic site and Aged Sea Salt for the urban background site). The similarity between the source profiles was quantified using two statistical analysis tools, Pearson correlation (PC) and Standardized Identity Distance (SID). According to Pearson coefficients five out of the eight source profiles present high (PC > 0.8) correlation (Mineral Dust, Biomass Burning, Sea Salt, Sulfates and Heavy Oil Combustion), one presented moderate (0.8 > PC > 0.6) correlation (Exhaust) and two low/no (PC < 0.6) correlation (non-Exhaust, Nitrates/Aged Sea Salt). The source profiles that appear to be more correlated are those of sources that are not expected to have high spatial variability because there are either natural/secondary and thus have a regional character or are emitted outside the urban agglomeration and are transported to both sites. According to SID four out of the eight sources have high statistical correlation (SID < 1) in the two sites (Mineral Dust, Sea salt, Sulfates, Heavy Oil Combustion). Biomass Burning was found to be the source that yielded different results from the two methodologies. The careful examination of the source profile of that source revealed the reason for this discrepancy. SID takes all the species of the profile equally into account, while PC might be disproportionally affected by a few numbers of species with very high concentrations. It is suggested, based on the findings of this work, that the combined use of both tools can lead the users to a thorough evaluation of the similarity of source profiles. This work is, to the best of our knowledge, the first time a study is focused on the quantitative comparison of the source profiles for sites inside the same urban agglomeration using statistical indicators.The study was supported by “CALIBRA/EYIE” (MIS 5002799) and “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and co-financed by Greece and the European Union (European Regional Development Fund). Collection and chemical analysis of samples were supported by LIFE + AIRUSE EU project (ENV/ES/584). Partial support was also received by H2020 ERAPLANET/SMURBS ERANET GA No 689443.Peer reviewe

Complications of Hickman-Broviac catheters in children with malignancies

The aim of this study was to explore the complications related to Hickman-Broviac central venous catheters (Hickman-Broviac CVCs) in children with cancer, their incidence, and possible associations of complications and premature removal of CVCs with a number of risk factors. During the study period (1 Jan 2000-31 Dec 2003), 223 CVCs were inserted in 198 children (117 boys, 81 girls) at a mean age of 5.73 years (95% CI 5.19-6.27, SE 0.275). In total, 76 (38.4%) children suffered from solid tumors and 122 (61.6%) from leukemia. The mean follow-up after CVC insertion was 232.5 days (95% CI 214.9-250.2, SE 8.94) for a total of 51,839 catheter-days. A complication occurred in 20.8% of them and in 9.6% the complication led to the removal of the catheter. The most frequent complications were infection (63.9%), obstruction (26.2%), accidental failure (8.2%), and rupture (1.6%). An overall incidence of 1.17 (0.38 and 0.79 for mechanical complication and infection, respectively) per 1000 catheter days for the development of a complication was recorded. Additionally, the study revealed more nonelective removals in cases of leukemia compared to those of solid tumors. Systemic use of CVC does not appear to increase significantly the number of complications, and thus CVC remains an effective and safe tool for the management of childhood malignancies. Copyright © Informa Healthcare USA, Inc

The role of miRNAs in endometrial cancer

miRNAs are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Since their discovery, miRNAs have been associated with every cell function including malignant transformation and metastasis. Endometrial cancer is the most common gynecologic malignancy. However, improvement should be made in interobserver agreement on histological typing and individualized therapeutic approaches. This article summarizes the role of miRNAs in endometrial cancer pathogenesis and treatment. © 2015 Future Medicine Ltd

Epigenetics in gastrointestinal stromal tumors: Clinical implications and potential therapeutic perspectives

Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal neoplasms affecting the gastrointestinal tract. Activating mutations in either the KIT or PDGFRa gene are the principal oncogenic triggers with the former accounting for more than 80 % of cases. In the small subset of GIST that are wild type for both the aforementioned changes, other germline or somatic mutations have been identified. GIST exhibit a highly variable clinical behavior and the main prognostic determinants are tumor size, mitotic rate, and location. It is, however, strongly believed that, beyond classic genetics, additional epigenetic phenomena such as DNA hypomethylation and hypermethylation, microRNA alterations, and chromatin modifications underlie GIST tumorigenesis and influence the clinical course and response to standard treatment. This review aims to illuminate current advances in terms of epigenetics in GIST, as well as possible implications in prognosis and therapeutics. © 2013 Springer Science+Business Media New York

Long term flux of Saharan dust to the Aegean Sea around the Attica region, Greece

In this study, Particulate Matter (PM) samples, collected during 2 summer and 2 winter months over a long-term period (1984-2012) at a suburban site in Athens (Greece), were used in order to examine the connection between Sahara dust long range transport events and mass concentrations of the aerosol mineral component, as well as the relative abundance of specific crustal components. As a result, the average deposition flux of dust to the Aegean Sea around the Attica Region, during days with Sahara dust transport events, was calculated. The elemental concentration of aerosol samples was determined by means of ET-AAS, ED-XRF. Mineral dust was chemically reconstructed by using the elemental concentrations of the crustal species based on their common oxides. Two different air mass transport models (HYSPLIT and FLEXTRA) were used for the identification of the days with dust transport events. The dust deposition velocity of the particles was calculated by using Stokes drag law, while the dust deposition flux was calculated taking into account the mean particle size of the aerosol coarse size fraction, which is dominated by the transported crustal component during Sahara dust intrusions. The mineral dust contribution was higher in summer, when dry weather conditions prevail. The Ca/Fe ratio was examined for all years, since this ratio is often used for the identification of Saharan dust events. For the years 1996 and 1998 the Ca/Fe ratio indicates an influence by local urban generated dust. The dust deposition flux per day of a Sahara intrusion event varied from 61 to 199 μg/m2 with an average value of 131 ± 41 μg/m2. The total dust deposition over the 4 month measuring period ranged from 237 to 2935 μg/m2. © 2017 Vasilatou,Manousakas, Gini, Diapouli, Scoullos and Eleftheriadis

Characterization of PM2.5 chemical composition at the Demokritos suburban station, in Athens Greece. The influence of Saharan dust

The aim of this work is to study the atmospheric concentrations of selected major and trace elements and ions found in PM2.5, at a suburban site in Athens, Greece, and discuss on the impact of the different sources. Special focus is given to the influence of Saharan dust episodes. The seasonal variability in the metal and ion concentrations is also examined. The results show that PM2.5 mass concentrations are significantly influenced by Saharan dust events; it is observed that when the PM2.5 concentration is higher than 25 μg/m3, five out of six times, the air mass crossed North Africa at an altitude within the boundary layer. Fe is found to be the element with the more significant seasonal variability, displaying much higher concentrations during cold period. The frequent Saharan dust intrusions in the cold period of this dataset may explain this result. Mineral dust and secondary aerosol are the main PM2.5 components (29 and 34%, respectively). During Saharan dust events, the concentration of mineral dust is increased by 35% compared to the days without dust intrusions, while an increase of 68% of the sea salt is also observed. During event days, PM2.5 concentrations are also increased by 14%. Anthropogenic components do not decrease during those days, while sulfate displays even a slight increase, suggesting enrichment of mineral dust with secondary sulfates. The results indicate that African dust intrusions add a rather significant PM pollution load even in the PM2.5 fraction, with implication to population exposure and human health. © 2017, Springer-Verlag Berlin Heidelberg

Changes in children&apos;s fatigue during the course of treatment for paediatric cancer

Background: Fatigue is described as one of the most distressing symptoms of cancer therapy; yet it has received limited clinical attention. Children are suffering from a symptom that is under-diagnosed during their treatment. Aim: The aim of this study is: (a) to assess the change in fatigue scores during cancer treatment according to children&apos;s perspectives, and (b) to describe the possible causes of fatigue from children&apos;s points of view. Sample and methods: The present study is part of an ongoing prospective study. The research group consisted of 40 (n = 40) children aged 7-12 years with cancer who are being followed up in the oncology clinic of a Greek children&apos;s hospital. After parental consent was obtained, data were collected using the Child Fatigue Scale and a sociodemographic data form. Results: The children with cancer reported a statistically significant increase in fatigue scores during their treatment (F = 6.846, P = 0.003). Gender was the only demographic factor associated with a significant increase in the fatigue scores (F = 4.857, P = 0.034). Conclusions: Cancer treatment was found significantly to increase children&apos;s fatigue levels. Medical procedures and the hospital environment seemed to be major causative factors of the fatigue experienced by children with cancer during their treatment. © 2008 The Authors

Evaluating cancer related fatigue during treatment according to children&apos;s, adolescents&apos; and parents&apos; perspectives in a sample of Greek young patients

Introduction: Cancer related fatigue in children and adolescents has received limited clinical attention. The aim of the study is to assess the change in fatigue scores during cancer treatment according to children&apos;s, adolescents&apos; and parents&apos; perspectives and to describe the possible causes of fatigue from children&apos;s, adolescents&apos; and parents&apos; view. Patients and methods: The sample consisted of 40 children aged 7-12 years old, 29 adolescents aged 13-15 years old with cancer and one of their parents. Three measurements were performed for the evaluation of cancer related fatigue. Three versions of the instrument for the assessment of fatigue in pediatric patients with cancer were used: «The Child Fatigue Scale» (CFS), «The Adolescent Fatigue Scale» (AFS) and «The Parent Fatigue Scale» (PFS). The survey was performed from March 2003 till October 2006. Results: Children (F = 6.85, p = 0.00), adolescents (F = 4.15, p = 0.03) and parents (F = 3.98, p = 0.02) reported a statistically significant increase in fatigue scores during their treatment. The hospital environment was assessed as the most contributing factor of fatigue by the three groups. Conclusions: Cancer treatment was found significantly to increase children&apos;s fatigue levels. Medical procedures and the hospital environment seemed to be major causative factors of the fatigue experienced by young patients with cancer during their treatment. © 2009 Elsevier Ltd. All rights reserved

The role of miRNAs and epigenetic mechanisms in primary gastric mucosa-associated lymphoid tissue lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare low-grade B-cell non-Hodgkin lymphoma associated with Helicobacter pylori infection and the subsequent chronic inflammation. Significant progress in understanding the pathogenesis of the disease has already been made. However, the exact molecular pathways of lymphomagenesis remain unclear. Furthermore, difficulties regarding accurate diagnosis of gastric MALT lymphoma and its discrimination from gastritis or other lymphoma subtypes arise. Recent studies evaluate the role of miRNAs and epigenetic alterations on MALT lymphoma pathogenesis and prognosis. This review critically summarizes the most important data on the role of miRNAs and epigenetics in MALT lymphomas pathogenesis, prognosis and treatment. © 2016 Future Medicine Ltd