Maximum Residue Level validation of triclabendazole marker residues in bovine liver, muscle and milk by UHPLC tandem mass spectrometry.

Triclabendazole is the only anthelmintic drug, which is active against immature, mature and adult stages of fluke. The objective of this work was to develop an analytical method to quantify and confirm the presence of triclabendazole residues around the MRL. In this work, a new analytical method was developed, which extended dynamic range to 1–100 and 5–1000 g kg-1 for milk and tissue, respectively. This was achieved using a mobile phase containing trifluoroacetic acid (pKa of 0.3), which resulted in the formation of the protonated pseudomolecular ions, [M+H]+, of triclabendazole metabolites. Insufficient
ionisation of common mobile phase additives due to low pKa values (<2) was identified as the cause of poor linearity. The new mobile phase conditions allowed the analysis of triclabendazole residues in liver, muscle and milk encompassing their EU maximum residue levels (MRL) (250, 225 and 10 g kg-1 respectively). Triclabendazole residues were extracted using a modified QuEChERS method and analysed by positive electrospray ionisation mass spectrometry with all analytes eluted by 2.23 min. The method was validated at the MRL according to Commission Decision (CD) 2002/657/EC criteria. The decision limit (CC) of the method was in the range of 250.8–287.2, 2554.9–290.8 and 10.9–12.1 g kg-1 for liver, muscle and milk, respectively. The performance of the method was successfully verified for triclabendazole in muscle by participating in a proficiency study, the method was also applied to incurred liver, muscle and milk samples.

Ferromagnetism in DyRh and DyRhX (X = Fe, Ni, Co, Gd) thin films

In an effort to achieve large high-field magnetization and increased Curie temperature, polycrystalline DyRh, (DyRh)95X5 and (DyRh)85X15 (X = Fe, Co, Ni, Gd) thin films have been prepared via ultra-high vacuum DC co-sputtering on SiO2 and Si wafers, using Ta as seed and cap material. A body-centred cubic CsCl-like crystal formation (B2 phase) was achieved for DyRh around the equiatomic equilibrium, known from single crystals. The maximum in-plane spontaneous magnetization at T = 4K in fields of μ0H = 5T of was found to be μ0MS,4K = (1.50 ± 0.09)T with a ferromagnetic transition at TC = (5 ± 1)K and a coercivity of μ0HC,4K[D] = (0.010 ± 0.001)T (at T = 4K) for layers deposited on substrates heated to 350°C. Samples prepared at room temperature exhibited poorer texture, smaller grains and less B2-phase content; this did impact on the Curie temperature which was higher compared to those layers with best crystallisation; however the maximal magnetization stayed unaffected. Ferromagnetic coupling was observed in ternary alloys of DyRhGd and DyRhNi with an increased Curie temperature, larger initial permeability, and
high-field magnetization which was best for (DyRh)85Gd15 with μ0MS,4K[Gd15] = (2.10 ± 0.13)T. DyRhFe and DyRhCo showed antiparallel coupling of the spontaneous magnetic moments.

Determination of the persistence of dimetridazole, metronidazole and ronidazole residues in black tiger shrimp (Penaeus monodon) tissue and stability during cooking

The depletion of three banned nitroimidazole drugs (dimetridazole (DMZ), metronidazole (MNZ) and ronidazole (RNZ)) was investigated in black tiger shrimp (Penaeus monodon) following in-water medication. The highest concentrations of residues were measured immediately after the 24 h immersion (day 0). At this time, MNZ and MNZ-OH residues were measured in shrimp tissue samples at concentrations ranging from 361–4189 and 0.28–6.6 μg kg−1, respectively. DMZ and its metabolites HMMNI ranged in concentration between 31509–37780 and 15.0–31.9 μg kg−1, respectively. RNZ and HMMNI concentrations ranged 14530–24206 and 25.0–55 μg kg−1, respectively. MNZ, DMZ and RNZ were the more persistent marker residues and can be detected for at least eight days post-treatment. MNZ-OH was only detectable on day 0 following treatment with MNZ. HMMNI residues were only detectable up to day 1 (0.97–3.2 μg kg−1) or 2 (1.2–4.5 μg kg−1) following DMZ and RNZ treatment, respectively. The parent drugs, MNZ, DMZ and RNZ were still measureable on day 8 at 0.12–1.00, 40.5–55 and 8.8–18.7 μg kg−1, respectively. The study also investigated the stability of nitroimidazole residues under various cooking procedures (frying, grilling, boiling and boiling followed by microwaving). The experiments were carried out in shrimp muscle tissue containing both high and low concentrations of these residues. Different cooking procedures showed the impact on nitroimidazole residue concentration in shrimp tissuetheir concentration depleted significantly, but partially, by boiling and/or microwaving but the compounds were largely resistant to conventional grilling or frying. Cooking cannot therefore be considered as a safeguard against harmful nitroimidazole residues in shrimp.

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - http://www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

Estudo de campo de verificação metrológica de termómetros clínicos timpânicos

Avaliação da variação da temperatura corporal, e a monitorização da mesma é bastante importante na prática clínica sendo, por vezes, a base de muitas decisões clínicas. Atualmente, os termómetros digitais, em particular os timpânicos são amplamente utilizados, em contexto hospitalar e domiciliário. Muitos estudos têm sido efetuados para determinar a validade das medições obtidas através de termómetros timpânicos. Os defensores destes termómetros afirmam que, se forem utilizados de forma adequada e periodicamente calibrados, a avaliação da temperatura corporal com este tipo de termómetros é eficaz, cómoda, rápida, pouco invasiva emais higiénica reduzindo o número de infeções cruzadas (FarnellMaxwell &Tan, Rhodes& Philips, 2005). A Metrologia como a ciência das medições e suas aplicações ((VIM1: 2.2) (INSTITUTO PORTUGUÊS DA QUALIDADE, 2012)), abrange todos os aspetos teóricos e práticos que asseguram a exatidão e precisão exigida num processo, procurando garantir a qualidade de produtos e serviços através da calibração de instrumentos de medição e da realização de ensaios, sendo a base fundamental para a competitividade das empresas. Só após o ano 1990, com a publicação dos resultados doHarvardMedical Practice Study (T A BRENNAN, 2004), sobre adventos adversos na área da saúde, começaram a surgir preocupação com o risco do uso de equipamentos e instrumentos sem a adequada avaliação metrológica. Neste estudo concluiu-se que 3,7 % dos pacientes hospitalizados sofriam eventos adversos devido ao uso inadequado de equipamento médico, sendo que 13,6% destes eram mortais. Pegando nesta realidade e sabendo que o não controlo de Equipamento de Monitorização e Medição é uma das causas de obtenção de 36%de não conformidades - 7.6 (NP EN ISO 9001:2008), em Auditorias da Qualidade em Serviços de Saúde (Luís Marinho – Centro Hospitalar São João), fez todo o sentido o estudo e trabalho desenvolvido. Foi efetuado um estudo, no que se refere a normalização em vigor e verificou-se que a nível metrológico muito trabalho terá que ser realizado no serviço nacional de saúde por forma este fornecer o suporte material fiável ao sistema de medições, essencial aos mais diversos sectores da saúde. Sabendo-se que os ensaios/calibrações são necessários e não são negligenciáveis na estrutura de custos das instituições de saúde, e por isso são vistas como mais uma fonte de despesas, é intenção com a realização deste trabalho, contribuir em parte para superação deste tema. Este trabalho passou pela execução/realização de um procedimento de calibração para termómetros timpânicos, tendo a necessidade de desenvolver/projetar um corpo negro. A amostra em estudo é constituída por cinco termómetros timpânicos hospitalares em uso dos diferentes serviços do CHSJ2, seleccionados completamente ao acaso. Um termómetro clínico no mínimo terá que ser calibrado a temperatura 35 ºC e 42 ºC. A calibração deverá ser realizada anualmente e por entidade acreditada. O erro máximo admissível é de ± 0,2 ºC (nas condições ambientais de funcionamento). Sem a confirmação metrológica, não é possível garantir a qualidade do produto ou serviço. A Metrologia na área da saúde desperta a exigência por produtos e serviços de qualidade. Esta tencionará ser encarada como um pilar de sustentabilidade para a qualidade na saúde, sendo absolutamente necessária a implementação de novos procedimentos e atitudes.

BAFF binds to the tumor necrosis factor receptor-like molecule B cell maturation antigen and is important for maintaining the peripheral B cell population.

The tumor necrosis factor (TNF) family member B cell activating factor (BAFF) binds B cells and enhances B cell receptor-triggered proliferation. We find that B cell maturation antigen (BCMA), a predicted member of the TNF receptor family expressed primarily in mature B cells, is a receptor for BAFF. Although BCMA was previously localized to the Golgi apparatus, BCMA was found to be expressed on the surface of transfected cells and tonsillar B cells. A soluble form of BCMA, which inhibited the binding of BAFF to a B cell line, induced a dramatic decrease in the number of peripheral B cells when administered in vivo. Moreover, culturing splenic cells in the presence of BAFF increased survival of a percentage of the B cells. These results are consistent with a role for BAFF in maintaining homeostasis of the B cell population.

Recueil de lettres originales.

Contient : 1 Lettre du roi « CHARLES » IX au « duc de Nemoux,... Au Boys de Vincennes, le XVIe jour d'avril 1574 » ; 2 Lettre du roi « CHARLES » IX au « duc de Nemoux,... Au Boys de Vincenes, le XXVe jour de may 1574 » ; 3 Lettre de « CATERINE [DE MEDICIS]... à... monseigneur le duc de Nemoux,... Au Boys de Vincenes, le XXVme jour de may 1574 » ; 4 Lettre du roi « CHARLES [IX]... à monseigneur le president Viart,... Au chasteau de Vincennes, le XXVe jour de may 1574 » ; 5 Lettre de « HENRY [III, roi de Navarre]... à madame la duchesse de Ferrare,... A Paris, ce IXme de juin 1574 » ; 6 Lettre de « CATERINE [DE MEDICIS]... à madame... la duchesse de Ferrare,... De Lion, cet XII de haust 157 IIII » ; 7 Lettre de « HENRY [III, roi de Navarre]... à madame... la duchesse de Ferrare,... A Lion, ce XIIIIe ottobre 1574 » ; 8 Lettre de « FRANÇOYS [duc D'ALENÇON]... à madame... la duchesse de Ferrare,... A Lyon, le XVe jour de octobre 1574 » ; 9 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara et duchessa di Chiartres,... Dalla corte, alli IIII di maggio M.D.LXXIIII » ; 10 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara et duchessa di Chiartres,... Dalla corte, alli VI di maggio M.D.LXXIIII » ; 11 Lettre de « JAQUES DE SAVOYE,... à madame [Renée de France, duchesse de Ferrare]... De Saint Ambrose, se 13me de may 1574 » ; 12 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara et duchessa di Chiartres,... Dalla corte Xma, alli XV di maggio M.D.LXXIIII » ; 13 Lettre, en italien, d'ALFONSE II, « duca DI FERRARA », au duc « di Nemours,... Di Ferrara, a XIX di maggio M.D.LXXIIII » ; 14 Lettre, en italien, de « CAROLO BIRAGO,... al... duca di [Nemours et de Genevois]... Da Saluce, li VI giugno 1574 » ; 15 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara, duchessa di Chiartrez,... Di Parigi, a XII di giugno 1574 » ; 16 Lettre de « JAQUELYNE DE ROHAN,... à madame... la duchesse [de Ferrare]... De Colombiers, ce 14e juin 1574 » ; 17 Lettre, en italien, de « LEONORA D'ESTE,... a... madama... di Ferrara,... Di Ferrara, a XXII di giugno del LXXIIII » ; 18 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara, duchessa di Chiartres,... Di Parigi, a XXIX di giugno 1574 » ; 19 Lettre, en italien, de « Don FRANCESCO DA ESTE,... a... madama duchessa di Ferrara,... Di Ferrara, li II di luglio nel LXXIIII » ; 20 Lettre, en italien, de « ALFONSO D'ESTE » à « madama... di Ferrara, duchessa di Chartres,... Di Ferrara, a 2 di luglio 1574 » ; 21 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara, duchessa di Chiartrez,... Di Parigi, a III di luglio 1574 » ; 22 Lettre de « LUIGI, cardinale D'ESTE », à la duchesse de Ferrare. « De Paris, ce cinqme juillet 1574 » ; 23 Lettre de « JAQUES DE SAVOYE,... à madame [Renée de France, duchesse de Ferrare]... De Chazey, ce XIIIe jour de juillet 1574 » ; 24 Lettre de « LUIGI, cardinale D'ESTE,... à madame... la duchesse de Ferrare,... De Paris, ce XVIIe juillet 1574 » ; 25 Lettre, en italien, de « LUIGI, cardinale D'ESTE », à la duchesse de Ferrare. « Di Parigi, a XX di luglio 1574 » ; 26 Lettre de « LUIGI, cardinale D'ESTE,... à madame... la duchesse de Ferrare,... De Paris, ce XXIIIIe juillet 1574 » ; 27 Lettre de « LUIGI, cardinale D'ESTE,... à madame... la duchesse de Ferrare,... De Paris, ce IIe jour d'aoust 1574 » ; 28 Lettre de « LUIGI, cardinale D'ESTE,... à madame... la duchesse de Ferrare,... Du VIIIe aoust 1574 » ; 29 Lettre de « MARGUERITE DE FRANCE [duchesse DE SAVOIE]... à... monsieur le duc de Nemours,... De Thurin, ce vingt huictiesme aoust 1574 » ; 30 Lettre de « LOYS, cardinal DE GUYSE,... à monsieur Viart,... A Lyon, le XXVIIIe aust 1574 » ; 31 Lettre de « JAQUES DE SAVOYE [duc DE NEMOURS]... à madame [Renée de France, duchesse de Ferrare]... De Lyon, ce XXe de setembre 1574 » ; 32 Lettre d'« E[MMANUEL] PHILIBERT [duc DE SAVOIE]... à... monsieur le duc de Genevois et de Nemours,... De Turin, ce XXIIIe septembre 1574 » ; 33 Lettre d'« E[MMANUEL] PHILIBERT [duc DE SAVOIE]... à... monsieur le duc de Nemours,... De Turin, ce XXIIIe 7bre 1574 » ; 34 Lettre, en italien, de « LUCRETIA D'ESTE [duchesse D'URBIN]... a... madama di Ferrara,... Di Pesaro, alli III d'ottobre 1574 » ; 35 Lettre de « MARGUERITE [DE FRANCE, duchesse DE SAVOIE]... à madame... la duchesse de Ferrare,... De Lyon, le XIIIIme jour d'octobre 1574 » ; 36 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara,... Di Lione, il di XIIII di ottobre 1574 » ; 37 Lettre d'« [EMMANUEL] PHILIBERT [duc DE SAVOIE]... à... monseigneur le duc de Genevoys et de Nemours,... De Turin, ce XXVe octobre 1574 » ; 38 Lettre, en italien, de « LUIGI, cardinale D'ESTE,... a... madama di Ferrara,... Di Lione, l'ultimo d'ottobre 1574 » ; 39 Lettre de HENRI « DE MONTMORENCY,... à monsieur... le duc de Nemours,... A Montpellier, ce XIXe de novembre 1574 » ; 40 Lettre, en italien, de CHARLES IV, « duca DI MANTOVA,... a... monseigneur [di] Nemors,... Di Mar[anel]lo, a 24 di novembre 1574 » ; 41 Lettre d'« E[MMANUEL] PHILIBERT [duc DE SAVOIE]... à madame... de Ferrare,... De Turin, ce IIIIe de decembre 1574 » ; 42 Lettre d'« ANNE DE SAVOYE,... à madame... la duchesse de Ferrare,... De La Salle, ce VIe decembre 1574 » ; 43 Lettre, en italien, de « Don FRANCESCO DA ESTE,... a... madama duchessa di Ferrara,... Di Ferrara, li VI di decembre nel LXXIIII » ; 44 Lettre, en italien, de la duchesse D'URBIN, « LUCRETIA D'ESTE,... a... madama di Ferrara, duchessa di Chiartres,... Di Pésaro, alli XI Xbre 1574 » ; 45 Lettre, en italien, de la duchesse D'URBIN, « LUCRETIA D'ESTE,... a... madama di Ferrara,... Di Pesaro, alli XIII Xbre 1574 » ; 46 Lettre, en italien, de « VITTORIA, duchessa D'URBINO,... a... madama [Renea] di Francia,... Di Pesaro, li XX Xbre 1574 » ; 47 Lettre, en italien, de FRANÇOIS-MARIE II, « duca D'URBINO... a... madama Renea di Francia,... Di Pesaro, li XXI di Xbre M.D.LXXIIII » ; 48 Lettre, en italien, de « LUCRETIA D'ESTE [duchesse D'URBIN],... a... madama di Ferrara,... Di Pesaro, alli XXII di decembre 1574 » ; 49 Minute d'une lettre de RENEE DE FRANCE, duchesse DE FERRARE, « à la royne [Catherine de Médicis]... Du IIIIe jour de juing 1574 »

ARTERIAL STIFFNESS IN CHILDREN WITH AND WITHOUT DEVELOPMENTAL COORDINATION DISORDER

The purpose of this study was to determine whether children with potential developmental coordination disorder (p-DCD) demonstrate increased arterial stiffness and thickness compared to age and school matched controls (mean age 14.7 yrs). We also assessed whether these measures differed by sex. Compliance, distensibility, and intima-media thickness (IMT) were measured at the common carotid artery for 28 children with p-DCD and 47 controls. ECG-R-wave-toe pulse wave velocity (PWV) was also measured for 29 children with p-DCD and 45 controls. We found that compared to controls males with p-DCD had significantly higher PWV (3.8±0.2 vs. 4.1±0.3, p=0.001) and lower distensibility (0.82± 0.19 vs. 0.70± 0.17, p=0.034) while females showed no significant differences (p=0.523 and p=0.123 respectively). As a result, it is apparent that sex differences exist with respect to arterial health within this population and that children with p-DCD may be more likely to develop cardiovascular disease later in life.

Letter - E.C. Schmon to Arthur A. Schmon, 29 & 30 January 1918

In this letter Eleanore Celeste talks about attending Church, magazines and her interest in education. She states "the more I learn, the thirstier I am for knowledge." The second letter mentions the Philips estate turning into a seniors facility for women after much talk about it possibly turning into a hospital for wounded officers. This letter is labelled number 50.

The Money Question and the Good Life

This paper proposes a theory of the good life for use in answering the question how much money the rich should spend on fighting poverty. The paper moves from the abstract to the concrete. To begin with, it investigates various ways to get an answer to the question what is good, and finds itself drawn to objective theories of the good. It then develops, taking Bernard Williams and Martha Nussbaum as its guides, a broad outline of a theory of the good. It holds that something evil happens to people if they do not have a real choice from a reasonable number of projects that realize most of their key capacities to a certain degree, and in connection to this it points to the great importance of money. The paper goes on specifically to consider what criticisms of Nussbaum's version of the capability approach are implied in this outline of a theory of the good. Next, it gets more specific and asks how much money the rich can give -and how they can be restricted in spending their money- without suffering any evil. It does three suggestions: the tithe suggestion, the ecological (or footprint) suggestion, and the fair trade suggestion. To conclude, the paper returns to the question how much money the rich should spend on fighting poverty.

NGO Duties in Relation to Human Rights. A Closer Look at One Proposal

This paper investigates the moral duties that human rights NGOs, such as Amnesty International, and development NGOs, such as Oxfam, have in relation to human rights – especially in relation to the human right to a decent standard of living. The mentioned NGOs are powerful new agents on the global scene, and according to many they might be duty-bearers in relation to human rights. However, until now their moral duties have hardly been investigated. The present paper investigates NGO duties in relation to human rights by looking in particular to a moral theory recently proposed by Leif Wenar, a theory which has some similarities to utilitarianism. In applying this theory, a case for human-rights duties of NGOs is developed mainly by considering the indispensable role that civil society plays in protecting human rights. The paper concludes that, at least, NGOs bear duties with regard to human rights when, as in certain real-life cases, NGO involvement is the only way to achieve acceptable protection against standard threats to certain goods, such as a decent standard of living.

Éloge et critique de l’empereur chez Ambroise de Milan et Symmaque : au confluent de deux conceptions idéologiques du pouvoir impérial romain

L’expression idéologique du pouvoir impérial romain au IVe siècle apr. J.-C. fut profondément marquée par les contextes religieux, culturel et littéraire dans lesquels elle s’inséra et dans lesquels coexistèrent deux religions et donc deux systèmes différents de pensée et de représentation du monde, soit le paganisme, religion traditionnelle de l’État romain, et le christianisme, religion émergente qui s’imposa de plus en plus dans l’Empire, notamment à partir du règne de Constantin. Cette trame de fond, loin de signifier à cette époque la fin totale du paganisme – comme il a longtemps été admis – au profit de la religion chrétienne qui entretint, grâce au support impérial, une relation nouvelle avec le pouvoir politique, modela de nouveaux critères d’exercice du pouvoir et des conceptions de l’idéal impérial qui s’exprimèrent dans les discours d’éloge destinés à l’empereur. Miroir du prince et moyen de communication entre ce dernier et l’élite, les éloges d’Ambroise de Milan et de Symmaque s’insérèrent dans le débat politique de leur temps en élaborant un archétype de l’empereur et en déterminant ses devoirs. Pour mesurer toute l’ampleur de la symbolique véhiculée dans de tels discours, il importe, pour le IVe siècle, de considérer la mentalité des auteurs, chrétiens et païens, d’où émanaient les éloges – ou encore les critiques – de la personne impériale. Ce mémoire propose ainsi d’analyser l’idéologie du pouvoir impérial selon les discours chrétien et païen, à travers les éloges d’Ambroise et de Symmaque, afin de relever les points de rencontre, d’influence ou de divergence entre ces représentations du monde et, plus spécifiquement, du pouvoir impérial, qui ont longtemps été considérées comme totalement opposées et incompatibles.

Radiothérapie asservie à la respiration en combinaison avec l'utilisation d'un faisceau sans filtre égalisateur

La radiothérapie stéréotaxique corporelle (SBRT) est une technique couramment employée pour le traitement de tumeurs aux poumons lorsque la chirurgie n’est pas possible ou refusée par le patient. Une complication de l’utilisation de cette méthode provient du mouvement de la tumeur causé par la respiration. Dans ce contexte, la radiothérapie asservie à la respiration (RGRT) peut être bénéfique. Toutefois, la RGRT augmente le temps de traitement en raison de la plus petite proportion de temps pour laquelle le faisceau est actif. En utilisant un faisceau de photons sans filtre égalisateur (FFF), ce problème peut être compensé par le débit de dose plus élevé d’un faisceau FFF. Ce mémoire traite de la faisabilité d’employer la technique de RGRT en combinaison avec l’utilisation un faisceau FFF sur un accélérateur Synergy S (Elekta, Stockholm, Suède) avec une ceinture pneumatique, le Bellows Belt (Philips, Amsterdam, Pays-Bas), comme dispositif de suivi du signal respiratoire. Un Synergy S a été modifié afin de pouvoir livrer un faisceau 6 MV FFF. Des mesures de profils de dose et de rendements en profondeur ont été acquises en cuve à eau pour différentes tailles de champs. Ces mesures ont été utilisées pour créer un modèle du faisceau 6 MV FFF dans le système de planification de traitement Pinnacle3 de Philips. Les mesures ont été comparées au modèle à l’aide de l’analyse gamma avec un critère de 2%, 2 mm. Par la suite, cinq plans SBRT avec thérapie en arc par modulation volumétrique (VMAT) ont été créés avec le modèle 6 MV du Synergy S, avec et sans filtre. Une comparaison des paramètres dosimétriques a été réalisée entre les plans avec et sans filtre pour évaluer la qualité des plans FFF. Les résultats révèlent qu’il est possible de créer des plans SBRT VMAT avec le faisceau 6 MV FFF du Synergy S qui sont cliniquement acceptables (les crières du Radiation Therapy Oncology Group 0618 sont respectés). Aussi, une interface physique de RGRT a été mise au point pour remplir deux fonctions : lire le signal numérique de la ceinture pneumatique Bellows Belt et envoyer une commande d’irradiation binaire au linac. L’activation/désactivation du faisceau du linac se fait par l’entremise d’un relais électromécanique. L’interface comprend un circuit électronique imprimé fait maison qui fonctionne en tandem avec un Raspberry Pi. Un logiciel de RGRT a été développé pour opérer sur le Raspberry Pi. Celui-ci affiche le signal numérique du Bellows Belt et donne l’option de choisir les limites supérieure et inférieure de la fenêtre d’irradiation, de sorte que lorsque le signal de la ceinture se trouve entre ces limites, le faisceau est actif, et inversement lorsque le signal est hors de ces limites. Le logiciel envoie donc une commande d’irradiation au linac de manière automatique en fonction de l’amplitude du signal respiratoire. Finalement, la comparaison entre la livraison d’un traitement standard sans RGRT avec filtre par rapport à un autre plan standard sans RGRT sans filtre démontre que le temps de traitement en mode FFF est réduit en moyenne de 54.1% pour un arc. De la même manière, la comparaison entre la livraison d’un traitement standard sans RGRT avec filtre par rapport à un plan de RGRT (fenêtre d’irradiation de 75%) sans filtre montre que le temps de traitement de RGRT en mode FFF est réduit en moyenne de 27.3% par arc. Toutefois, il n’a pas été possible de livrer des traitements de RGRT avec une fenêtre de moins de 75%. Le linac ne supporte pas une fréquence d’arrêts élevée.