82 research outputs found

    Skip Training for Multi-Agent Reinforcement Learning Controller for Industrial Wave Energy Converters

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    Recent Wave Energy Converters (WEC) are equipped with multiple legs and generators to maximize energy generation. Traditional controllers have shown limitations to capture complex wave patterns and the controllers must efficiently maximize the energy capture. This paper introduces a Multi-Agent Reinforcement Learning controller (MARL), which outperforms the traditionally used spring damper controller. Our initial studies show that the complex nature of problems makes it hard for training to converge. Hence, we propose a novel skip training approach which enables the MARL training to overcome performance saturation and converge to more optimum controllers compared to default MARL training, boosting power generation. We also present another novel hybrid training initialization (STHTI) approach, where the individual agents of the MARL controllers can be initially trained against the baseline Spring Damper (SD) controller individually and then be trained one agent at a time or all together in future iterations to accelerate convergence. We achieved double-digit gains in energy efficiency over the baseline Spring Damper controller with the proposed MARL controllers using the Asynchronous Advantage Actor-Critic (A3C) algorithm.Comment: 2022 IEEE 18th International Conference on Automation Science and Engineering (CASE) August 20-24, 202

    RANTES/CCL5 and Risk for Coronary Events: Results from the MONICA/KORA Augsburg Case-Cohort, Athero-Express and CARDIoGRAM Studies

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    BACKGROUND: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. METHODS AND FINDINGS: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±4.8 years). Cox proportional hazard models adjusting for age, sex, body mass index, metabolic factors and lifestyle factors revealed no significant association between RANTES and incident coronary events (HR [95% CI] for increasing RANTES tertiles 1.0, 1.03 [0.75-1.42] and 1.11 [0.81-1.54]). None of six CCL5 single nucleotide polymorphisms and no common haplotype showed significant associations with coronary events. Also in the CARDIoGRAM study (>22,000 cases, >60,000 controls), none of these CCL5 SNPs was significantly associated with coronary artery disease. In the prospective Athero-Express biobank study, RANTES plaque levels were measured in 606 atherosclerotic lesions from patients who underwent carotid endarterectomy. RANTES content in atherosclerotic plaques was positively associated with macrophage infiltration and inversely associated with plaque calcification. However, there was no significant association between RANTES content in plaques and risk for coronary events (mean follow-up 2.8±0.8 years). CONCLUSIONS: High RANTES plaque levels were associated with an unstable plaque phenotype. However, the absence of associations between (i) RANTES serum levels, (ii) CCL5 genotypes and (iii) RANTES content in carotid plaques and either coronary artery disease or incident coronary events in our cohorts suggests that RANTES may not be a novel coronary risk biomarker. However, the potential relevance of RANTES levels in platelet-poor plasma needs to be investigated in further studies

    RANTES/CCL5 and risk for coronary events: Results from the MONICA/KORA Augsburg case-cohort, Athero-express and CARDIoGRAM studies

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    Background: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. Methods and Findings: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±

    Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

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    Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways

    Etude d'un nouvel anticorps anti-CD37 radiomarqué au Lutétium-177 dans le traitement du lymphome B non hodgkinien : efficacité thérapeutique et mécanismes d'action

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    Currently, B-cell Non-Hodgkin Lymphoma (NHL) treatment relies on the anti-CD20 antibody rituximab and chemotherapy. However, some patients become refractory to this therapy. Here, the effect of the novel anti-CD37 antibody-radionuclide conjugate 177Lu-lilotomab (Betalutin®) was investigated in NHL preclinical models and compared to 177Lu-labeled rituximab (anti-CD20 antibody). We developed a radiobiological approach that discriminates between the cytotoxic effects of unlabeled antibodies and of radiation in human lymphoma cell lines. This method allowed showing that in vitro, rituximab and 177Lu-rituximab were more cytotoxic than lilotomab and 177Lu-lilotomab in the radioresistant Ramos Burkitt’s lymphoma cell line. Conversely, 177Lu-rituximab and 177Lu-lilotomab had similar efficacy in the radiosensitive follicular lymphoma DOHH2 cell line. Their cytotoxicity was lower in mantle cell lymphoma Rec-1 cells that are less radiosensitive than DOHH2 cells. These results were confirmed in vivo in mice treated by intravenous injection of these antibodies after subcutaneous xenografts of Ramos or DOHH2 cells. 177Lu-lilotomab and 177Lu-rituximab showed the same therapeutic efficacy in mice xenografted with radiosensitive DOHH2 cells, although unlabeled lilotomab was less efficient than rituximab. Conversely, in mice xenografted with radioresistant Ramos cells, the lower efficacy of 177Lu-lilotomab compared with 177Lu-rituximab could only be compensated by increasing 177Lu-lilotomab tumor absorbed dose. Mechanistically, the tumor cell response to radiation depended on the cell apoptotic response and reduction of G2/M cell cycle arrest through WEE-1 and MYT1-mediated phosphorylation of cyclin-dependent kinase-1 (CDK1) at tyrosine 15 and threonine 14. These results indicate that the synergistic interaction between 177Lu irradiation and lilotomab cytotoxic effects in tumors with reduced CDK1 phosphorylation levels can correct the lower therapeutic efficacy of lilotomab compared with rituximab.Le traitement du lymphome B non hodgkinien (NHL) est généralement basé sur la combinaison d’un anticorps monoclonal anti-CD20, le rituximab, et de la chimiothérapie. Cependant, de nombreux patients deviennent réfractaires au ciblage du récepteur CD20. Dans cette thèse, l’effet d’un nouvel anticorps monoclonal anti-CD37 conjugué au Luthétium-177 (177Lu-lilotomab, Betalutin®) est étudié dans des modèles précliniques de lymphome non hodgkinien et comparé au rituximab radiomarqué au luthétium-177 (177Lu-rituximab). Nous avons développé une approche radiobiologique qui distingue les effets cytotoxiques dus à l’anticorps monoclonal et dus aux rayonnements ionisants dans des lignées cellulaires de lymphome humain. Cette méthode a permis de montrer qu’in vitro, le rituximab et le 177Lu-rituximab étaient plus cytotoxiques que le lilotomab et le 177Lu-lilotomab dans la lignée cellulaire radiorésistante Ramos (modèle du lymphome de Burkitt). Inversement, le 177Lu-lilotomab et le 177Lu-rituximab ont montré la même cytotoxicité dans la lignée cellulaire radiosensible DOHH2 (modèle de lymphome folliculaire transformé). Leur cytotoxicité était plus faible dans la lignée cellulaire Rec-1 (modèle du lymphome du manteau) que dans les cellules DOHH2. Ces résultats ont été confirmés in vivo sur des souris traitées par injection intraveineuse après xénogreffe sous-cutanée de cellules Ramos ou DOHH2. Le 177Lu-lilotomab et le 177Lu-rituximab ont montré la même efficacité thérapeutique chez les souris xénogreffées avec les cellules radiosensibles DOHH2, alors que le lilotomab non radiomarqué était moins efficace que le rituximab. Inversement, chez les souris xénogreffées avec les cellules radiorésistantes Ramos, la plus faible efficacité du 177Lu-lilotomab comparé au 177Lu-rituximab peut seulement être compensée par une augmentation de dose absorbée à la tumeur par le 177Lu-lilotomab. Mécanistiquement, la réponse cellulaire des tumeurs aux radiations dépend de la réponse apoptotique des cellules et de la réduction de l’arrêt en G2/M du cycle cellulaire via les phosphorylations médiées par WEE-1 et MYT-1 de la kinase dépendante des cyclines-1 (CDK1) sur la tyrosine 15 et thréonine 14. Ces résultats indiquent que l’interaction synergistique entre les effets cytotoxiciques du 177Lu et du lilotomab dans les tumeurs montrant une réduction des niveaux de phosphorylations de CDK1 peut compenser le manque d’efficacité thérapeutique du lilotomab comparé au rituximab

    Study of a new anti-CD37 monoclonal antibody radiolabelled with Luthetium-177 in a B-cell Non-Hodgkin Lymphoma : therapeutic efficacy and mechanisms of action

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    Le traitement du lymphome B non hodgkinien (NHL) est généralement basé sur la combinaison d’un anticorps monoclonal anti-CD20, le rituximab, et de la chimiothérapie. Cependant, de nombreux patients deviennent réfractaires au ciblage du récepteur CD20. Dans cette thèse, l’effet d’un nouvel anticorps monoclonal anti-CD37 conjugué au Luthétium-177 (177Lu-lilotomab, Betalutin®) est étudié dans des modèles précliniques de lymphome non hodgkinien et comparé au rituximab radiomarqué au luthétium-177 (177Lu-rituximab). Nous avons développé une approche radiobiologique qui distingue les effets cytotoxiques dus à l’anticorps monoclonal et dus aux rayonnements ionisants dans des lignées cellulaires de lymphome humain. Cette méthode a permis de montrer qu’in vitro, le rituximab et le 177Lu-rituximab étaient plus cytotoxiques que le lilotomab et le 177Lu-lilotomab dans la lignée cellulaire radiorésistante Ramos (modèle du lymphome de Burkitt). Inversement, le 177Lu-lilotomab et le 177Lu-rituximab ont montré la même cytotoxicité dans la lignée cellulaire radiosensible DOHH2 (modèle de lymphome folliculaire transformé). Leur cytotoxicité était plus faible dans la lignée cellulaire Rec-1 (modèle du lymphome du manteau) que dans les cellules DOHH2. Ces résultats ont été confirmés in vivo sur des souris traitées par injection intraveineuse après xénogreffe sous-cutanée de cellules Ramos ou DOHH2. Le 177Lu-lilotomab et le 177Lu-rituximab ont montré la même efficacité thérapeutique chez les souris xénogreffées avec les cellules radiosensibles DOHH2, alors que le lilotomab non radiomarqué était moins efficace que le rituximab. Inversement, chez les souris xénogreffées avec les cellules radiorésistantes Ramos, la plus faible efficacité du 177Lu-lilotomab comparé au 177Lu-rituximab peut seulement être compensée par une augmentation de dose absorbée à la tumeur par le 177Lu-lilotomab. Mécanistiquement, la réponse cellulaire des tumeurs aux radiations dépend de la réponse apoptotique des cellules et de la réduction de l’arrêt en G2/M du cycle cellulaire via les phosphorylations médiées par WEE-1 et MYT-1 de la kinase dépendante des cyclines-1 (CDK1) sur la tyrosine 15 et thréonine 14. Ces résultats indiquent que l’interaction synergistique entre les effets cytotoxiciques du 177Lu et du lilotomab dans les tumeurs montrant une réduction des niveaux de phosphorylations de CDK1 peut compenser le manque d’efficacité thérapeutique du lilotomab comparé au rituximab.Currently, B-cell Non-Hodgkin Lymphoma (NHL) treatment relies on the anti-CD20 antibody rituximab and chemotherapy. However, some patients become refractory to this therapy. Here, the effect of the novel anti-CD37 antibody-radionuclide conjugate 177Lu-lilotomab (Betalutin®) was investigated in NHL preclinical models and compared to 177Lu-labeled rituximab (anti-CD20 antibody). We developed a radiobiological approach that discriminates between the cytotoxic effects of unlabeled antibodies and of radiation in human lymphoma cell lines. This method allowed showing that in vitro, rituximab and 177Lu-rituximab were more cytotoxic than lilotomab and 177Lu-lilotomab in the radioresistant Ramos Burkitt’s lymphoma cell line. Conversely, 177Lu-rituximab and 177Lu-lilotomab had similar efficacy in the radiosensitive follicular lymphoma DOHH2 cell line. Their cytotoxicity was lower in mantle cell lymphoma Rec-1 cells that are less radiosensitive than DOHH2 cells. These results were confirmed in vivo in mice treated by intravenous injection of these antibodies after subcutaneous xenografts of Ramos or DOHH2 cells. 177Lu-lilotomab and 177Lu-rituximab showed the same therapeutic efficacy in mice xenografted with radiosensitive DOHH2 cells, although unlabeled lilotomab was less efficient than rituximab. Conversely, in mice xenografted with radioresistant Ramos cells, the lower efficacy of 177Lu-lilotomab compared with 177Lu-rituximab could only be compensated by increasing 177Lu-lilotomab tumor absorbed dose. Mechanistically, the tumor cell response to radiation depended on the cell apoptotic response and reduction of G2/M cell cycle arrest through WEE-1 and MYT1-mediated phosphorylation of cyclin-dependent kinase-1 (CDK1) at tyrosine 15 and threonine 14. These results indicate that the synergistic interaction between 177Lu irradiation and lilotomab cytotoxic effects in tumors with reduced CDK1 phosphorylation levels can correct the lower therapeutic efficacy of lilotomab compared with rituximab

    Développement de faisceaux d ions radioactifs pour le projet SPIRAL 2

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    Cette thèse concerne l'étude de la production de faisceaux d'ions radioactifs par la méthode ISOL pour le projet SPIRAL 2. La production de faisceaux légers est tout d abord considérée. Les taux de production potentiels de deux faisceaux sont évalués : la production de 15C (riche en neutrons) dans une cible d oxyde est estimée à l aide de simulations (MCNPx, EAF-07) et de données expérimentales ; le taux de production d 14O (déficient en neutrons) est estimé par une nouvelle mesure de la fonction d excitation de la réaction 12C(3He,n)14O. Une première conception de la cible de production basée sur des simulations thermiques est présentée. Cette étude apporte les réponses nécessaires à la conception détaillée d un système qui permettrait d atteindre un taux de production 140 fois plus élevé qu avec SPIRAL 1. La production des faisceaux d ions radioactifs issus de fissions dans une cible d UCx est aussi étudiée, et plus particulièrement les processus d effusion et d ionisation. Une étude de principe et une campagne de tests hors ligne ont permis d acquérir des connaissances indispensables à la conception de la source à ionisation de surface de SPIRAL 2. Un premier prototype de cette source dédiée à la production d éléments alcalins et alcalino-terreux a été réalisé et une calibration thermique a été effectuée. Les efficacités d ionisation et de temps de réponse sur l ensemble cible source ECR ont été mesurées à différentes températures de la cible et pour différents gaz nobles. Ces mesures ont permis d estimer l impact des processus d effusion et d ionisation sur l efficacité de production de différents isotopes d alcalins et de gaz nobles en fonction de leur durée de vie.This thesis focuses on the study of radioactive ion beam production by the ISOL method for the SPIRAL 2 project. The production of light ion beams is studied and the potential in-target yields of two beams are appraised. The neutron-rich 15C yield in an oxide target is estimated with simulations (MCNPx, EAF-07) and experimental data bases; the neutron-deficient 14O yield is estimated thanks to a new measurement of the 12C(3He,n)14O reaction excitation function. Based on thermal simulations, a first design of the production target is presented. This thermal study gives the necessary answers for the detailed design of the system able to reach a production yield 140 times higher than with SPIRAL 1. The production of radioactive ion beams coming from fissions in the UCx target is also studied and more particularly effusion and ionisation processes. A global study and an off-line tests campaign allow essential knowledge to the design of the surface ionisation source for SPIRAL 2 to be acquired. A first prototype of this ion source dedicated to alkali and alkaline-earth element production has been built and a thermal calibration performed. Ionisation efficiency and time response of the target-ion source system have been measured at different target temperatures and for different noble gases. These measurements allow evaluation of the impact of effusion and ionisation processes on the production efficiency of different alkali and noble gases isotopes as a function of their half-life.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

    Fc-engineered monoclonal antibodies to reduce off-target liver uptake

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    Abstract Background Radiolabeled-antibodies usually display non-specific liver accumulation that may impair image analysis and antibody biodistribution. Here, we investigated whether Fc silencing influenced antibody biodistribution. We compared recombinant 89Zr-labeled antibodies (human IgG1 against different targets) with wild-type Fc and with mutated Fc (LALAPG triple mutation to prevent binding to Fc gamma receptors; FcγR). After antibody injection in mice harboring xenografts of different tumor cell lines or of immortalized human myoblasts, we analyzed antibody biodistribution by PET-CT and conventional biodistribution analysis. Results Accumulation in liver was strongly reduced and tumor-specific targeting was increased for the antibodies with mutated Fc compared with wild-type Fc. Conclusion Antibodies with reduced binding to FcγR display lower liver accumulation and better tumor-to-liver ratios. These findings need to be taken into account to improve antibody-based theragnostic approaches
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