844 research outputs found
Geochemical mapping of urban soils in Athens, Greece - Preliminary results
Η αστική γεωχημεία είναι ένας αναπτυσσόμενος επιστημονικός τομέας κυρίως λόγω των περιβαλλοντικών επιπτώσεων από την εξάπλωση των πόλεων και την αύξηση του αστικού πληθυσμού. Η παρούσα εργασία έχει ως στόχο τη γεωχημική χαρτογράφηση των επιφανειακών (0-10 cm) εδαφών της Αθήνας με έμφαση στη χωρική κατανομή δυνητικά βλαβερών χημικών στοιχείων. Η δειγματοληψία υπαίθρου πραγματοποιήθηκε βάσει τετραγωνικού κανάβου ισοδιάστασης 1 km και κάλυψε συνολική έκταση περίπου 200 km2, με προτεραιότητα σε παιδικές χαρές, σχολεία και πάρκα. Αναλύθηκαν320 εδαφικά δείγματα κοκκομετρίας < 100 μm με την τεχνική της φασματοσκοπίας ατομικής απορρόφησης μετά από διαλυτοποίηση με βασιλικό ύδωρ και προσδιορί- στηκαν τα στοιχεία Pb, Zn, Cu, Cd, Cr, Ni, Co και Mn. Οι μέσες συγκεντρώσεις των στοιχείων Pb (62 mg/kg), Cu (36 mg/kg), Zn (91 mg/kg) και Mn (465 mg/kg) είναι χαμηλότερες των αντίστοιχων συγκεντρώσεων άλλων Ευρωπαϊκών πόλεων ενώ οι συγκεντρώσεις των Cr (74 mg/kg), Ni (89 mg/kg) και Co (16 mg/kg) υψηλότερες. Το γεωχημικό ανάγλυφο αποτυπώθηκε σε περιβάλλον ΓΣΠ δίνοντας τη δυνατότητα προσδιορισμού διαφορετικών πηγών των στοιχείων. Τα αποτελέσματα της έρευνας συμβάλουν στην εκτίμηση της ποιότητας των εδαφών της Αθήνας και αποτελούν πολύτιμο εργαλείο στην αναγνώριση περιοχών περιβαλλοντικής επικινδυνότητας.Urban geochemistry is a fast growing scientific discipline mainly because of the profound impact of large cities on the environment as well as the increase in the world’s urban population. The present study aims to produce the urban geochemical map of Athens, based on multi-element analysis of surface soils (0-10 cm) with emphasis in the spatial distribution of potentially harmful elements (PHEs). Soil sampling was based on a regular 1km x 1km grid, laid over the survey area covering more than 200 km2. Sampling locations within the grid cells were selected giving priority to playgrounds, schools and urban parks. The < 100 μm fraction of a total of 320 soil samples were analysed by Flame Atomic Absorption Spectroscopy for Pb, Zn, Cu, Cd, Cr, Ni, Co and Mn after aqua regia dissolution. Average content of Pb (62 mg/kg), Cu (36 mg/kg), Zn (91 mg/kg) and Mn (465 mg/kg) in soil was lower than reported concentrations from other European cities while Cr (74 mg/kg), Ni (89 mg/kg) and Co (16 mg/kg) were relatively enriched. Geochemical maps were plotted within GIS enabling recognition of spatial trends in elemental concentrations and potential sources of the elements. The research outcome will contribute to the evaluation of quality characteristics of urban soils in Athens and drive attention to areas of any environmental or health risks
Laparoscopic Approach to Incarcerated and Strangulated Inguinal Hernias
Introduction: Acute inguinal hernias are a common presentation as surgical emergencies, which have been routinely managed with open surgery. In recent years, the laparoscopic approach has been described by several authors but has been controversial amongst surgeons. We describe the laparoscopic approach to incarcerated/strangulated inguinal hernias based on a review of the literature with regards to its feasibility in laparoscopically managing the acute hernia presentation. Methods: A systematic literature search was carried out including Medline with PubMed as the search engine, and Ovid, Embase, Cochrane Collaboration, and Google Scholar databases to identify articles reporting on laparoscopic treatment, reduction, and repair of incarcerated or strangulated inguinal hernias from 1989 to 2008. Results: Forty-three articles were found, and 7 were included according to the inclusion criteria set. Articles reporting on the use of laparoscopy for the evaluation of the hernia but not reducing and repairing it, the use of the open technique, elective hernia repairs, pediatric series, review articles, and other kinds of hernias were excluded after title and abstract review. This resulted in 16 articles that were reviewed in full. Of these 16 articles, 7 reported on the use of the laparoscopic approach exclusively. From these 7 studies, there were 328 cases reported, 6 conversions, average operating time of 61.3 minutes (SD 12.3), average hospital stay of 3.8 days (SD 1.2), 34 complications (25 of which were reported as minor), and 17 bowel resections performed either laparoscopically or through a minilaparotomy incision guided laparoscopically. Conclusion: The laparoscopic repair is a feasible procedure with acceptable results; however, its efficacy need
Higher-order ratios of baryon number cumulants
The relevance of higher order cumulants of net baryon number fluctuations for
the analysis of freeze-out and critical conditions in heavy-ion collisions at
LHC and RHIC is addressed. The sign structure of the higher order cumulants in
the vicinity of the chiral crossover temperature might be a sensitive probe and
may allow to elucidate their relation to the QCD phase transition. We calculate
ratios of generalized quark-number susceptibilities to high orders in three
flavor QCD-like models and investigate their sign structure close to the chiral
crossover line.Comment: presented at the International Conference "Critical Point and Onset
of Deconfinement - CPOD 2011", Wuhan, November 7-11, 2011; version to appear
in Cent. Eur. J. Phy
Obstetric outcomes after conservative treatment for cervical intraepithelial lesions and early invasive disease.
BACKGROUND: The mean age of women undergoing local treatment for pre-invasive cervical disease (cervical intra-epithelial neoplasia; CIN) or early cervical cancer (stage IA1) is around their 30s and similar to the age of women having their first child. Local cervical treatment has been correlated to adverse reproductive morbidity in a subsequent pregnancy, however, published studies and meta-analyses have reached contradictory conclusions. OBJECTIVES: To assess the effect of local cervical treatment for CIN and early cervical cancer on obstetric outcomes (after 24 weeks of gestation) and to correlate these to the cone depth and comparison group used. SEARCH METHODS: We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library, 2017, Issue 5), MEDLINE (up to June week 4, 2017) and Embase (up to week 26, 2017). In an attempt to identify articles missed by the search or unpublished data, we contacted experts in the field and we handsearched the references of the retrieved articles and conference proceedings. SELECTION CRITERIA: We included all studies reporting on obstetric outcomes (more than 24 weeks of gestation) in women with or without a previous local cervical treatment for any grade of CIN or early cervical cancer (stage IA1). Treatment included both excisional and ablative methods. We excluded studies that had no untreated reference population, reported outcomes in women who had undergone treatment during pregnancy or had a high-risk treated or comparison group, or both DATA COLLECTION AND ANALYSIS: We classified studies according to the type of treatment and the obstetric endpoint. Studies were classified according to method and obstetric endpoint. Pooled risk ratios (RR) and 95% confidence intervals (CIs) were calculated using a random-effects model and inverse variance. Inter-study heterogeneity was assessed with I2 statistics. We assessed maternal outcomes that included preterm birth (PTB) (spontaneous and threatened), preterm premature rupture of the membranes (pPROM), chorioamnionitis, mode of delivery, length of labour, induction of delivery, oxytocin use, haemorrhage, analgesia, cervical cerclage and cervical stenosis. The neonatal outcomes included low birth weight (LBW), neonatal intensive care unit (NICU) admission, stillbirth, perinatal mortality and Apgar scores. MAIN RESULTS: We included 69 studies (6,357,823 pregnancies: 65,098 pregnancies of treated and 6,292,725 pregnancies of untreated women). Many of the studies included only small numbers of women, were of heterogenous design and in their majority retrospective and therefore at high risk of bias. Many outcomes were assessed to be of low or very low quality (GRADE assessment) and therefore results should be interpreted with caution. Women who had treatment were at increased overall risk of preterm birth (PTB) (less than 37 weeks) (10.7% versus 5.4%, RR 1.75, 95% CI 1.57 to 1.96, 59 studies, 5,242,917 participants, very low quality), severe (less than 32 to 34 weeks) (3.5% versus 1.4%, RR 2.25, 95% CI 1.79 to 2.82), 24 studies, 3,793,874 participants, very low quality), and extreme prematurity (less than 28 to 30 weeks) (1.0% versus 0.3%, (RR 2.23, 95% CI 1.55 to 3.22, 8 studies, 3,910,629 participants, very low quality), as compared to women who had no treatment.The risk of overall prematurity was higher for excisional (excision versus no treatment: 11.2% versus 5.5%, RR 1.87, 95% CI 1.64 to 2.12, 53 studies, 4,599,416 participants) than ablative (ablation versus no treatment: 7.7% versus 4.6%, RR 1.35, 95% CI 1.20 to 1.52, 14 studies, 602,370 participants) treatments and the effect was higher for more radical excisional techniques (less than 37 weeks: cold knife conisation (CKC) (RR 2.70, 95% CI 2.14 to 3.40, 12 studies, 39,102 participants), laser conisation (LC) (RR 2.11, 95% CI 1.26 to 3.54, 9 studies, 1509 participants), large loop excision of the transformation zone (LLETZ) (RR 1.58, 95% CI 1.37 to 1.81, 25 studies, 1,445,104 participants). Repeat treatment multiplied the risk of overall prematurity (repeat versus no treatment: 13.2% versus 4.1%, RR 3.78, 95% CI 2.65 to 5.39, 11 studies, 1,317,284 participants, very low quality). The risk of overall prematurity increased with increasing cone depth (less than 10 mm to 12 mm versus no treatment: 7.1% versus 3.4%, RR 1.54, 95% CI 1.09 to 2.18, 8 studies, 550,929 participants, very low quality; more than 10 mm to 12 mm versus no treatment: 9.8% versus 3.4%, RR 1.93, 95% CI 1.62 to 2.31, 8 studies, 552,711 participants, low quality; more than 15 mm to 17 mm versus no treatment: 10.1 versus 3.4%, RR 2.77, 95% CI 1.95 to 3.93, 4 studies, 544,986 participants, very low quality; 20 mm or more versus no treatment: 10.2% versus 3.4%, RR 4.91, 95% CI 2.06 to 11.68, 3 studies, 543,750 participants, very low quality). The comparison group affected the magnitude of effect that was higher for external, followed by internal comparators and ultimately women with disease, but no treatment. Untreated women with disease and the pre-treatment pregnancies of the women who were treated subsequently had higher risk of overall prematurity than the general population (5.9% versus 5.6%, RR 1.24, 95% CI 1.14 to 1.34, 15 studies, 4,357,998 participants, very low quality).pPROM (6.1% versus 3.4%, RR 2.36, 95% CI 1.76 to 3.17, 21 studies, 477,011 participants, very low quality), low birth weight (7.9% versus 3.7%, RR 1.81, 95% CI 1.58 to 2.07, 30 studies, 1,348,206 participants, very low quality), NICU admission rate (12.6% versus 8.9%, RR 1.45, 95% CI 1.16 to 1.81, 8 studies, 2557 participants, low quality) and perinatal mortality (0.9% versus 0.7%, RR 1.51, 95% CI 1.13 to 2.03, 23 studies, 1,659,433 participants, low quality) were also increased after treatment. AUTHORS' CONCLUSIONS: Women with CIN have a higher baseline risk for prematurity. Excisional and ablative treatment appears to further increases that risk. The frequency and severity of adverse sequelae increases with increasing cone depth and is higher for excision than it is for ablation. However, the results should be interpreted with caution as they were based on low or very low quality (GRADE assessment) observational studies, most of which were retrospective
Takotsubo cardiomyopathy and sepsis: a systematic review
Takotsubo cardiomyopathy (TTC) is characterized by a systolic dysfunction localized in the apical and medial aspect of
the left ventricle. It is usually related to physical or emotional stress. Recent evidence highlighting the role of infection
led us to analyze the links between TTC and sepsis. A systematic review of the literature was undertaken to assess any
trends in clinical findings, diagnosis, and outcomes in such patients. We identified 23 selected papers reporting a total of
26 patients, having sepsis, in whom TTC occurred. For each case, we collected data identifying population characteristics,
source of sepsis, clinical disease description, and the results of cardiovascular investigations. The majority of patients
were females (n = 16), mean age was 62.8 (14.0 standard deviation) years, and clinical outcome was favorable in 92.3% of
the cases once the management of sepsis was initiated. A better understanding of the mechanisms of sepsis-associated
TTC may generate novel strategies to treat the complications of this cardiomyopathy and may even help predict and
prevent its occurrence
Philanthropy or solidarity? Ethical dilemmas about humanitarianism in crisis afflicted Greece
That philanthropy perpetuates the conditions that cause inequality is an old argument shared by thinkers such as Karl Marx, Oscar Wilde and Slavoj Zizek. I recorded the same argument in conversations regarding a growing humanitarian concern in austerity-ridden Greece. At the local level a number of solidarity initiatives provide the most impoverished families with humanitarian help. Some citizens participate in such initiatives wholeheartedly, while some other citizens criticize solidarity movements drawing primarily from Marxist-inspired arguments, such as, for example, that humanitarianism rationalises state inaction. The local narratives presented in this article bring forward two parallel possibilities engendered by the humanitarian face of social solidarity: first, its empowering potential (where solidarity initiatives enhance local social awareness), and second, the de-politicisation of the crisis and the experience of suffering (a liability that stems from the effectiveness of humanitarianism in ameliorating only temporarily the superficial consequences of the crisis). These two overlapping possibilities can help us problematise the contextual specificity and strategic employment of humanitarian solidarity in times of austerity
Modeling of flow and transport processes occurred in a typical polymer electrolyte membrane fuel cell (PEMFC)
Abstract. In the present work, a three dimensional model examining the fluid flow along with the fundamental transport phenomena occurring in a typical polymer electrolyte fuel cell (PEMFC), i.e. heat transfer, mass transport and charge transfer, has been developed. The flow field was simulated according to the well known Navier-Stokes equations, while the heat transfer was described by the typical conduction/convection equation and the mass transport by the convection/diffusion one. Furthermore, reaction kinetics were studied by the Butler-Volmer equation for the heterogeneous reactions occurring at the porous electrodes. The developed model was numerically solved by using the commercially available CFD package CFD-RC © , which is based on the multi-step finite volume method. The fuel cell performance in terms of velocity, temperature, mass fractions of active compounds and electric field has been investigated as well. Introduction Fuel cell systems are energy devices that directly convert the chemical energy of the feeding fuel into electricity without Carnot limitation, being suitable for stationary and mobile applications. Due to the high conversion efficiencies and the negligible environmental impact, fuel cell technology is considered as one of the most promising to contribute essentially to generation of electrical power in the near futur
Successful combined surgical approach in a rare case of retrotracheal goitre in a patient with anatomical impediments
Diving goitres can descend the cervical region expanding directly into the thoracic cavity. In most cases, diving goitres extend into the anterosuperior compartment, but they may also extend behind the trachea. We herein present a case of a male patient with retrotracheal goitre and history of left thyroid lobectomy and median sternotomy for thoracic aortic aneurysm repair with graft placement. After detailed preoperative evaluation, the patient underwent surgical resection of the mass through a combined approach; the existing cervical incision and a right posterolateral mini-thoracotomy. The postoperative course of the patient was uncomplicated. One year after surgery, the patient is asymptomatic and disease-free. (Folia Morphol 2018; 77, 1: 166–169
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