153 research outputs found

    20. Setting the pace for strengthening radiotherapy in Europe: the estro esquire project

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    In most medical specialties the success rate and outcome of treatment coincide and can be measured immediately. This is not the case for radiotherapy where debilitating of even lethal side effects may show up as late as 18 years after treatment. To determine the outcome or therapeutic ratio of radiotherapy, it is therefore necessary to link tumour control closely to the actuarial long-term disease free survival of the patient.The therapeutic window for radiotherapy is narrow. In walking the tightrope between cure and complications, radiotherapy can put the odds at its side. As a precautionary measure, strict quality assurance measures including the monitoring of side effects need to be put in place. Recent studies have demonstrated that every gain in the accuracy of the beam output and treatment delivery is translated into important gains in the uncomplicated cure probability, thus sparing the lives of thousands of patients every year. QA will become all the more mandatory now that new technological developments allow much more precision in the delivery of the intended dose to the intended target volume, thus making an escalation of the dose and hence the improvement of the cancer cure rata possible.Europe has only half the number of treatment units of America and Japan. However, it has also its own strengths. These are exactly in the field of quality assurance and education. ESTRO has become a world leader in the provision of teaching in the field of radiotherapy. The ESTRO teaching programme commands the admiration and even the envy of the International radiation oncology community. We need to capitalise on this achievement and keep it at the cutting edge of scientific and technological progress to offset, through the development of the human potential and optima) use of capital-intensive infrastructural resources, at least partially the shortage in capital investment and the past shortfall in spending for research.For this reason ESTRO is embarking on an ambitious new project called ESQUIRE (Education, Science and Quality Assurance In Radiotherapy in Europe) which it hopes to realise with the support of EU funding. The aim of this project is to increase the confidence level of clinicians for embracing optimised RT treatment regimes by making sure they can be introduced without an increase in severe side effects. Actions proposed for this purpose: monitoring the accuracy of the dose (Talk 1:E∼UAL) and the side effects (Task 2: REACT), by stepping up education for the implementation of new technology (Task 3: EDRO,) by developing quality assurance procedures for optimised RT (Task 5: QUASIMODO) and brachytherapy (Task 6: BRAPHY∼S), and establishing a procedure-based surveillance of quality in treatment and research (Task 4:EPOQART)

    Advanced control system for optimal filtration in submerged anaerobic MBRs (SAnMBRs)

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    The main aim of this study was to develop an advanced controller to optimise filtration in submerged anaerobic MBRs (SAnMBRs). The proposed controller was developed, calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes with variable influent flow and load. This 2-layer control system is designed for membranes operating sub-critically and features a lower layer (on/off and PID controllers) and an upper layer (knowledge-based controller). The upper layer consists of a MIMO (multiple-input-multiple-output) control structure that regulates the gas sparging for membrane scouring and the frequency of physical cleaning (ventilation and back flushing). The filtration process is monitored by measuring the fouling rate on-line. This controller demonstrated its ability to keep fouling rates low (close to 0 mbar mm(-1)) by applying sustainable gas sparging intensities (approx. 0.23 Nm(3) h(-1) m(-2)). It also reduced the downtimes needed for ventilation and back-flushing (less than 2% of operating time).This research has been supported by the Spanish Research Foundation (CICYT Projects CTM2008-06809-C02-01 and CTM2008-06809-C02-02, and MICINN FPI Grant BES-2009-023712) and Generalitat Valenciana (Projects GVA-ACOMP2010/130 and GVA-ACOMP2011/182), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Ferrer, J. (2013). Advanced control system for optimal filtration in submerged anaerobic MBRs (SAnMBRs). Journal of Membrane Science. 430:330-341. https://doi.org/10.1016/j.memsci.2012.11.078S33034143

    Gastrointestinal complications of accidental ingestion of foreign objects

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    Ingestion of foreign objects is common and most of the time, they pass without major problems. However sometimes they could cause significant morbidity or even mortality. Most of the time they cause pain in the pharyngeal or oesophageal area. In these instants, diagnosing the problem is straightforward, limiting the use of radiographic diagnosis.However the intraperitoneal complications include stomach or bowel perforation, obstruction, abscedation, septicemia or even hemorrhage or thrombosis of the abdominal veins. Because of the considerable risks, accompanied by the accidental ingestion of a metallic object, the preferred technique for screening is still Computed Tomography. However not all of these objects are radio-opaque and therefore could not always be diagnosed radiographically. In this article we will describe several cases of complications, due to the accidental ingestion of foreign objects. Also we will describe certain patient related risk factors significantly increasing, not only the amount, but also the severity of those complications. Diverticulosis seems the most common risk factor amongst the patients described and so it could be one of the more common triggers causing (recidivating) diverticulitis attacks. But because not all of the ingested foreign objects are radiopaque or still in the gastrointestinal tract, such a theory is difficult to prove

    DEFAUT DE PAIEMENT, COMPORTEMENT DE SAUVE-QUI-PEUT ET TRAITEMENT DES CREANCIERS

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    This article analyzes the economic effeciency of legal rules of bankruptcy. It aims to answer the following question : do the legal rules of bankruptcy allow an efficient solution to the problem of sauve-qui-peut or opportunistic behavior inherent in bankruptcy firm ? I adopt a model of games theory between two creditors. I define the condition of strategic behavior emergency and demonstrate who bears the cost. I analyze the impact of legal rules on the reduction of the strategic behavior. I demonstrate none of these rules of law is adequate to solve the problem of bankruptcy efficiently. I provide a new rule of contrat, and show how my analysis of the contrat infuence the strategic behavior

    Factors that affect the permeability of commercial hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system

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    A demonstration plant with two commercial HF ultrafiltration membrane modules (PURON (R), Koch Membrane Systems, PUR-PSH31) was operated with urban wastewater. The effect of the main operating variables on membrane performance at sub-critical and supracritical filtration conditions was tested. The physical operating variables that affected membrane performance most were gas sparging intensity and back-flush (BF) frequency. Indeed, low gas sparging intensities (around 0.23 Nm(3) h(-1) m(-2)) and low BF frequencies (30s back-flush for every 10 basic filtration relaxation cycles) were enough to enable membranes to be operated sub-critically even when levels of mixed liquor total solids were high (up to 25 g L-1). On the other hand, significant gas sparging intensities and BF frequencies were required in order to maintain long-term operating at supra-critical filtration conditions. After operating for more than two years at sub-critical conditions (transmembrane flux between 9 and 13.3 LMH at gas sparging intensities of around 0.23 Nm(3) h(-1) m(-2) and MLTS levels from around 10-30 g L-1) no significant irreversible/irrecoverable fouling problems were detected (membrane permeability remained above 100 LMH bar(-1) and total filtration resistance remained below 10(13) m(-1)), therefore no chemical cleaning was conducted. Membrane performance was similar to the aerobic HF membranes operated in full-scale MBR plants. (C) 2012 Elsevier Ltd. All rights reserved.This research work has been supported by the Spanish Research Foundation (CICYT Projects CTM2008-06809-C02-01 and CTM2008-06809-C02-02, and MICINN FPI grant BES-2009-023712) and Generalitat Valenciana (Projects GVA-ACOMP2010/130 and GVA-ACOMP2011/182), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Ferrer, J. (2013). Factors that affect the permeability of commercial hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system. Water Research. 47(3):1277-1288. https://doi.org/10.1016/j.watres.2012.11.055S1277128847

    The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids

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    The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW, fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago
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