24 results on '"Université de Caen Normandie (UNICAEN)"'
Search Results
2. Impact of socio-economic environment on incidence of primary liver cancer in France between 2006 and 2016.
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Comoz, Bertille, Ollivier-Hourmand, Isabelle, Bouvier, Anne-Marie, Nousbaum, Jean-Baptiste, Thi Thu Nga Nguyen, Launoy, Guy, Bouvier, Véronique, and Bryere, Joséphine
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LIVER cancer , *NOSOLOGY , *HEPATOCELLULAR carcinoma , *POISSON regression , *TUMOR classification , *AGE groups - Abstract
Background and Aims: To measure the impact of socio-economic environment on the incidence of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Method: The study used data from the French Network of Cancer Registries (FRANCIM) between 2006 and 2016. Classification of patients into HCC and iCCA was performed according to the topographical and morphological codes of the 3rd edition of the International Classification of Diseases for Oncology. Patient addresses were geolocalized and assigned to an IRIS, the smallest French geographic unit. Socio-economic environment was assessed by the European Deprivation Index (EDI). Sex- and age-standardized incidence rates with 95% confidence intervals (CI) were estimated per 100 000 inhabitants, by national quintiles, for each IRIS, sex and age group. Quintile 1 (Q1) characterized the most affluent areas. A Poisson regression was performed to model the impact of deprivation. Results: We included 22 249 cases (79.64% HCC, 16.97% iCCA). Incidence rates were 11.46 and 2.39 per 100 000 person-years for HCC and iCCA, respectively. There was an over-incidence of HCC in quintiles 2, 3, 4 and 5 compared to quintile 1: Q1 10.28 [9.9--10.66] per 100 000 person-years, Q2 11.43 [10.48--12.47] (p < .0001), Q3 11.81 [10.82--12.89] (p < .0001), Q4 12.26 [11.25--13.37] (p < .001) and Q5 11.53 [10.57-- 12.57] (p < .0001). By contrast, there was no difference for iCCa. Deprivation was significantly associated with HCC in men (p = .0018) and women (p = .0009), but not with iCCA (p = .7407). Conclusion: The incidence of HCC is related to socio-economic environment, unlike iCCA. HCC and iCCA should be studied separately in epidemiological studies. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Cephalopod learning and memory.
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Jozet-Alves, Christelle, Schnell, Alexandra K., and Clayton, Nicola S.
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SEASHELLS , *SQUIDS , *COGNITIVE ability , *FOOD preferences , *ASSOCIATIVE learning , *MEMORY , *CENTRAL nervous system - Abstract
Cephalopod molluscs are renowned for their unique central nervous system — a donut-shaped brain organised around the oesophagus. This brain supports sophisticated learning and memory abilities. Between the 1950s and 1980s, these cognitive abilities were extensively studied in octopus (Figure 1A) — a now leading model for the study of memory and its neural substrates (approximately 200 papers during this period). The focus on octopus learning and memory was mainly due to their curious nature and the fact that they adapt to laboratory-controlled conditions, making them easy to test and maintain in captivity. Research on cephalopod cognition began to widen in the late 20th century, when scientists started focusing on other coleoid cephalopods (i.e. , cuttlefish and squid) (Figure 1B,C), and not just on associative learning and memory per se , but other more complex aspects of cognition such as episodic-like memory (the ability to remember the what, where, and when of a past event), source memory (the retrieval of contextual details from a memory), and self-control (the ability to inhibit an action in the present to gain a more valuable future reward). Attention broadened further over the last two decades to focus on the shelled cephalopods — the nautiloids (Figure 1D). The nautiloids have relatively primitive brains compared to their soft-bodied cousins (octopus, cuttlefish, and squid) but research shows that they are still able to comparatively succeed in some cognitive tasks. In this primer, we will provide a general description of the types of memory studied in cephalopods, and discuss learning and memory experiments that address the main challenges cephalopods face during their daily lives: navigation, timing, and food selection. Determining the type of information cephalopods learn and remember and whether they use such information to overcome ecological challenges will highlight why these invertebrates evolved large and sophisticated brains. Jozet-Alves et al. describe the surprising learning and memory abilities of cephalopods, explaining how these abilities are employed in these animals' natural habitats. [ABSTRACT FROM AUTHOR]
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- 2023
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4. How Retting Could Affect the Mechanical Behavior of Flax/Epoxy Biocomposite Materials?
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Ragoubi, Mohamed, Lecoublet, Morgan, Khennache, Mehdi, Atanase, Leonard Ionut, Poilane, Christophe, and Leblanc, Nathalie
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FLAX , *EPOXY resins , *ELASTIC modulus , *FIBERS , *NATURAL fibers - Abstract
This study focuses on the retting effect on the mechanical properties of flax biobased materials. For the technical fiber, a direct link was established between the biochemical alteration of technical flax and their mechanical properties. In function of the retting level, technical fibers appeared smoother and more individualized; nevertheless, a decrease in the ultimate modulus and maximum stress was recorded. A biochemical alteration was observed as the retting increased (a decrease in the soluble fraction from 10.4 ± 0.2 to 4.5 ± 1.2% and an increase in the holocellulose fractions). Regarding the mechanical behavior of biocomposites manufactured by thermocompression, a non-elastic behavior was observed for the tested samples. Young moduli (E1 and E2) gradually increased with retting. The retting effect was more pronounced when a normalization was performed (according to the fiber volume and porosity). A 40% increase in elastic modulus could be observed between under-retting (−) and over-retting (+). Moreover, the porosity content (Vp) increased overall with fiber content. Setup 3, with optimized processing parameters, was the most desirable processing protocol because it allowed the highest fiber fraction (Vf) for the lowest Vp. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Early infectious risk in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis according to remission-induction therapy.
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Gérard, M, de Boysson, H, Morello, R, Martin-Silva, N, Leroux, A-C, Dumont, A, Maigné, G, Boutemy, J, Khoy, K, Mariotte, D, Lobbedez, T, Aouba, A, and Deshayes, S
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MICROSCOPIC polyangiitis , *REMISSION induction , *ANTINEUTROPHIL cytoplasmic antibodies , *WEGENER'S granulomatosis , *VASCULITIS - Abstract
Few comparative data exist on early infections secondary to remission-induction therapy (RIT) with rituximab (RTX) versus cyclophosphamide (CYC) in newly diagnosed anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients. We compared and analysed the rates and predictors of severe infection in such patients within the first 6 months following RIT. From the Caen University Hospital databases, we included all consecutive adults newly diagnosed with ANCA-positive granulomatosis with polyangiitis or microscopic polyangiitis between January 2006 and December 2019. We compared rates of survival without severe infection and survival without infections of any severity within 6 months of RIT and used a multivariate Cox analysis to identify predictors of infection. We included 145 patients, 27 in the RTX and 118 in the CYC group. Patients in the RTX group more frequently had pneumococcal vaccination (p < 0.01) and creatinine < 150 µmol/L; other characteristics were comparable between the two groups. Overall, 37 severe infections and 65 infections of any severity were recorded. Rates of survival without severe infection were similar in both groups (p = 0.69), but survival without infections of any severity was lower in the RTX group (p = 0.005). In multivariate analysis, risk factors at diagnosis for severe infections included chronic urinary tract disease, dialysis, and absence of trimethoprim–sulfamethoxazole prophylaxis (p < 0.01 each). Within 6 months of RIT, rates of survival without severe infection were similar in newly diagnosed ANCA-positive AAV patients treated with RTX or CYC, but survival rates without infections of any severity appeared to be lower with RTX treatment. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Metabolic oscillations during cell-cycle progression.
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Icard, Philippe and Simula, Luca
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CELL cycle , *OSCILLATIONS , *LIGASES , *CANCER cells , *KINASES - Abstract
We discuss how metabolism changes during different phases of the cell cycle to sustain biosynthesis and replication in normal and cancer cells. We also highlight how several master regulators of cell cycle, such as cyclin–cyclin-dependent kinases (cyc–CDK complexes) and E3 proteasome ligases, modulate key metabolic enzymes to support cell-cycle progression. [ABSTRACT FROM AUTHOR]
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- 2022
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7. Advancing environmental monitoring across the water continuum combining biomarker analysis in multiple sentinel species: A case study in the Seine-Normandie Basin (France).
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Slaby, Sylvain, Geffard, Alain, Fisson, Cédric, Bonnevalle-Normand, Matthieu, Allonier-Fernandes, Anne-Sophie, Amara, Rachid, Bado-Nilles, Anne, Bonnard, Isabelle, Bonnard, Marc, Burlion-Giorgi, Mayélé, Cant, Amélie, Catteau, Audrey, Chaumot, Arnaud, Costil, Katherine, Coulaud, Romain, Delahaut, Laurence, Diop, Mamadou, Duflot, Aurélie, Geffard, Olivier, and Jestin, Emmanuel
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ENVIRONMENTAL monitoring , *BIOMARKERS , *WATER management , *ECOLOGICAL assessment , *BIOLOGICAL monitoring , *ENVIRONMENTAL quality - Abstract
Nowadays, biomarkers are recognized as valuable tools to complement chemical and ecological assessments in biomonitoring programs. They provide insights into the effects of contaminant exposures on individuals and establish connections between environmental pressure and biological response at higher levels. In the last decade, strong improvements in the design of experimental protocols and the result interpretation facilitated the use of biomarker across wide geographical areas, including aquatic continua. Notably, the statistical establishment of reference values and thresholds enabled the discrimination of contamination effects in environmental conditions, allowed interspecies comparisons, and eliminated the need of a reference site. The aim of this work was to study freshwater-estuarine-coastal water continua by applying biomarker measurements in multi-species caged organisms. During two campaigns, eight sentinel species, encompassing fish, mollusks, and crustaceans, were deployed to cover 25 sites from rivers to the sea. As much as possible, a common methodology was employed for biomarker measurements (DNA damage and phagocytosis efficiency) and data interpretation based on guidelines established using reference values and induction/inhibition thresholds (establishment of three effect levels). The methodology was successfully implemented and allowed us to assess the environmental quality. Employing multiple species per site enhances confidence in observed trends. The results highlight the feasibility of integrating biomarker-based environmental monitoring programs across a continuum scale. Biomarker results align with Water Framework Directive indicators in cases of poor site quality. Additionally, when discrepancies arise between chemical and ecological statuses, biomarker findings offer a comprehensive perspective to elucidate the disparities. Presented as a pilot project, this work contributes to gain insights into current biomonitoring needs, providing new questions and perspectives. • A novel strategy to monitor aquatic continua using biomarkers is proposed. • A common analysis method was applied in multi-species caged organisms. • Biomarkers provide clear and easily useable assessment of the environmental quality. • Reference values and thresholds are recommended to interpret biomarker responses. • Biomarker-based monitoring on a wide scale complements the WFD evaluation. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Assessing the potential of BirdNET to infer European bird communities from large-scale ecoacoustic data.
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Funosas, David, Barbaro, Luc, Schillé, Laura, Elger, Arnaud, Castagneyrol, Bastien, and Cauchoix, Maxime
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BIRD communities , *EUROPEAN communities , *MACHINE learning , *DEEP learning , *ARTIFICIAL intelligence - Abstract
• We analyze 629 environmental soundscapes both with BirdNET and by manual listening. • Confidence thresholds can be reliably used to optimize for either precision or recall. • BirdNET IDs can be highly reliable if a high minimum confidence threshold is used. • F1-scores remain moderate (<0.5) for all datasets and confidence thresholds studied. • Best results are obtained when analyzing acoustic datasets of extended duration. 1. Passive acoustic monitoring has become increasingly popular as a practical and cost-effective way of obtaining highly reliable acoustic data in ecological research projects. Increased ease of collecting these data means that, currently, the main bottleneck in ecoacoustic monitoring projects is often the time required for the manual analysis of passively collected recordings. In this study we evaluate the potential and current limitations of BirdNET-Analyzer v2.4, the most advanced and generic deep learning algorithm for bird recognition to date, as a tool to assess bird community composition through the automated analysis of large-scale ecoacoustic data. 2. To this end, we study 3 acoustic datasets comprising a total of 629 environmental soundscapes collected in 194 different sites spread across a 19° latitude span in Europe. We analyze these soundscapes using both BirdNET and manual listening by local expert birders, and we then compare the results obtained through the two methods to evaluate the performance of the algorithm both at the level of each single vocalization and for entire recording sequences (1, 5 or 10 min). 3. Since BirdNET provides a confidence score for each identification, minimum confidence thresholds can be used to filter out identifications with low scores, thus retaining only the most reliable ones. The volume of ecoacoustic data used in this study did not allow us to estimate species-specific minimum confidence thresholds for most taxa, so we instead used and evaluated global confidence thresholds selected for optimized results when consistently applied across all species. 4. Our analyses reveal that BirdNET identifications can be highly reliable if a sufficiently high minimum confidence threshold is used. However, the inevitable trade-off between precision and recall does not allow to obtain satisfactory results for both metrics at the same time. We found that F1-scores remain moderate (<0.5) for all datasets and confidence thresholds studied, and that acoustic datasets of extended duration seem to be currently necessary for BirdNET to provide a reliable and minimally comprehensive picture of the target bird community. We estimate, however, that the usage of species- and context-specific minimum confidence thresholds would allow to substantially improve the global performance benchmarks obtained in this study. 5. We conclude that a judicious use of AI-based identifications provided by BirdNET can represent a powerful method to assist in the assessment of bird community composition through the automated analysis of ecoacoustic data, especially when applied to acoustic datasets of extended duration. [ABSTRACT FROM AUTHOR]
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- 2024
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9. A cockle-induced bioturbation model and its impact on sediment erodibility: A meta-analysis.
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Lehuen, Amélie and Orvain, Francis
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- 2024
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10. Novel thienopyrimidones targeting hepatic and erythrocytic stages of Plasmodium parasites with increased microsomal stability.
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Lagardère, Prisca, Mustière, Romain, Amanzougaghene, Nadia, Hutter, Sébastien, Casanova, Marion, Franetich, Jean-François, Tajeri, Shahin, Malzert-Fréon, Aurélie, Corvaisier, Sophie, Since, Marc, Azas, Nadine, Vanelle, Patrice, Verhaeghe, Pierre, Primas, Nicolas, Mazier, Dominique, Masurier, Nicolas, and Lisowski, Vincent
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CYTOTOXINS , *PLASMODIUM , *PARASITES , *DEUTERIUM , *5G networks , *LIVER cells - Abstract
Based on the structure of a previously identified hit, Gamhepathiopine 1 , which showed promising antiplasmodial activity, but poor microsomal stability, several strategies were investigated to improve the metabolic stability of the compounds. This included the introduction of fluorine or deuterium atoms, as well as carbocyclic groups. Among the new compounds, the 2-aminocyclobutyl derivative 5g demonstrated enhanced microsomal stability compared to compound 1 , while retaining antiplasmodial activity against erythrocytic and hepatic stages of Plasmodium , without significant cytotoxicity against primary hepatocytes. [Display omitted] • A series of 18 new thienopyrimidones was synthesized. • 6 compounds showed an EC 50 ≤ 1.5 μM against the blood stage of P. falciparum K1. • 5 compounds showed higher activity against the hepatic stage of P. berghei than Gamhepathiopine. • 3 compounds exhibited improved microsomal stability compared to Gamhepathiopine. • Compound 5g showed the better compromise between activity, cytotoxicity and microsomal stability. [ABSTRACT FROM AUTHOR]
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- 2023
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11. Postoperative radiotherapy after flap reconstructive surgery in patients with head and neck cancer: A retrospective monocentric study with flap delineation to assess toxicity and relapse.
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Gérard, M., Le Guevelou, J., Jacksic, N., Lequesne, J., Bastit, V., Géry, B., Jeanne, C., Batalla, A., Lacroix, J., Kammerer, E., Lasne-Cardon, A., and Thariat, J.
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HEAD & neck cancer , *POSTOPERATIVE care , *PLASTIC surgery , *CANCER relapse , *SURGICAL flaps - Abstract
Flaps are increasingly used during reconstructive surgery of head and neck cancers to improve functional outcomes. There are no guidelines as to whether the whole flap or its anastomotic border should be included in the primary tumour target volume of postoperative radiotherapy to prevent local relapses. Relapse and toxicity rates can increase substantially if the whole flap received full dose. Our aim was to determine whether flaps were included in the primary tumour target volume and to report the patterns of relapse and toxicity. Consecutive patients in 2014 through 2016, with or without a flap, receiving postoperative radiotherapy were selected in a retrospective monocentric control study. Flaps were homogenously delineated blind to treating radiation oncologists using a flap-specific atlas. Tumour recurrence, acute and late toxicity were evaluated using univariate and propensity score analyses. A hundred patients were included; 54 with a flap. Median flap volume included in the tumour volume was 80.9%. Twelve patients experienced local recurrences: six with a flap, among whom two within their flap (3.7%). Patients with flaps had larger median tumour volumes to be irradiated (25 cm3 versus 58 cm3, p < 0.001) and higher acute/late toxicity rates (p < 0.001) even after adjustment on biases (more advanced T stage, oral cavity, active smoking in patients with flaps). Locoregional recurrence and survival rates were similar between patients with/without a flap. Recurrences within a flap were rare in this series when including the whole flap body in the 60Gy-clinical target volume but inclusion of the flap in the primary tumour target volume increased toxicity. Multicentric studies are warranted. [ABSTRACT FROM AUTHOR]
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- 2020
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12. Tachycardies ventriculaires réfractaires : quelle place pour la radiothérapie et comment ?
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Jumeau, R., Pruvot, É., Thariat, J., Latorzeff, I., Milliez, P.-U., Champ-Rigot, L., De Crevoisier, R., and Ferchaud, V.
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Les tachycardies ventriculaires secondaires à la présence de zones cicatricielles hétérogènes au sein du myocarde représentent une forme d'arythmie grave dégradant la qualité de vie et pouvant engager le pronostic vital à court terme. La prévention de la mort subite rythmique et des récidives repose sur le défibrillateur automatique implantable, les médicaments antiarythmiques et plus récemment sur l'ablation par radiofréquence. Néanmoins ces approches présentent des risques d'effets indésirables et de complications, avec un taux de récidive qui reste élevé, pouvant atteindre 50 % à 2 ans. La radiothérapie stéréotaxique corporelle en dose unique de 25 Gy est apparue comme un nouvel outil non invasif de prise en charge complémentaire des tachycardies ventriculaires hautement réfractaires, qui peuvent concerner plusieurs dizaines de patients par an en France. Ainsi, en 2017 la toute première série prospective de cinq patients atteints de tachycardies ventriculaires récidivantes sur cardiopathie structurelle (dont 40 % de cardiopathies ischémiques) ayant bénéficié d'une radiothérapie stéréotaxique corporelle cardiaque a été publiée. Après la radiothérapie stéréotaxique corporelle, les auteurs ont pu observer une réduction marquée de la charge en tachycardies ventriculaires à 12 mois, sans effet indésirable majeur à court terme. Depuis, une centaine de cas de patients traités ont été décrits dans la littérature, notamment dans l'étude prospective ENCORE-VT avec des résultats à court et moyen termes plutôt positifs en termes de sécurité et de réduction de la charge en tachycardies ventriculaires. Récemment, une autre série prospective américaine parue en mars 2020 menée chez cinq patients nuançait ces résultats avec une récidive rythmique chez la totalité des patients à 12 mois, malgré une réduction initiale observée. Cet article décrit l'utilisation de la radiothérapie stéréotaxique corporelle pour les tachycardies ventriculaires réfractaires, son rationnel d'utilisation, sa mise en œuvre, ses résultats préliminaires et ses potentielles conséquences à court, moyen et long termes. Myocardial scar-related ventricular tachycardia is a serious and potentially life-threatening arrhythmia. The prevention of sudden rhythmic death and ventricular tachycardia recurrence relies on implantable cardioverter defibrillator (ICD), anti-arrhythmic drugs and more recently on radiofrequency catheter ablation. Nevertheless, these approaches have their own risk of adverse events and complications, with a recurrence rate up to 50 % at 2 years. Stereotactic body radiotherapy, delivered in a single dose of 25 Gy, has emerged as a new therapeutic tool in the management of highly refractory ventricular tachycardia. In 2017, the very first prospective 5-patient cohort suffering from recurrent ventricular tachycardia on structural heart disease (40 % of ischemic cardiomyopathy) who benefited from cardiac stereotactic body radiotherapy was published. After stereotactic body radiotherapy, the authors observed a strong ventricular tachycardia burden reduction at 12 months, with no major side effects. Since then, around 100 cases have been described in the literature, particularly in the prospective ENCORE-VT study, with positive short- and medium-term outcomes in terms of safety and ventricular tachycardia burden reduction. Recently, another American prospective 5-patient series, published in March 2020, mitigated these results since all patients presented a ventricular tachycardia recurrence at 12 months despite an initial reduction in ventricular tachycardia burden. This article describes the use of stereotactic body radiotherapy in refractory VT, the rationale of the technique, its implementation, preliminary results and potential acute and long-term consequences. [ABSTRACT FROM AUTHOR]
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- 2020
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13. Incertitudes inhérentes au concept actuel de volume cible prévisionnel en radiothérapie.
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Noël, G., Thariat, J., and Antoni, D.
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Le volume cible prévisionnel (planning target volume, PTV) est une notion essentielle en radiothérapie, il est nécessaire de faire évoluer son concept. En effet, la variabilité et la diversité des incertitudes apparaissant avec le développement des nouvelles technologies et des nouveaux dispositifs en radiothérapie suggèrent que les erreurs aléatoires et systématiques ne peuvent actuellement être généralisées. Cet article tente de discuter de ces différentes incertitudes et de démontrer qu'une redéfinition du concept de volume cible prévisionnel vers sa personnalisation pour chaque patient est nécessaire, la notion de robustesse est probablement une base d'amélioration pour prendre en compte les incertitudes de radiothérapie. The planning target volume is an essential notion in radiotherapy, that requires a new conceptualization. Indeed, the variability and diversity of the uncertainties involved or improved with the development of the new modern technologies and devices in radiotherapy suggest that random and systematic errors cannot be currently generalized. This article attempts to discuss these various uncertainties and tries to demonstrate that a redefinition of the concept of planning target volume toward its personalization for each patient and the robustness notion are likely an improvement basis to take into account the radiotherapy uncertainties. [ABSTRACT FROM AUTHOR]
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- 2020
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14. Radioresistant tumours: From identification to targeting.
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Cohen-Jonathan-Moyal, É., Vendrely, V., Motte, L., Balosso, J., and Thariat, J.
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TUMOR microenvironment , *CANCER cell proliferation , *TUMOR markers , *HYPOXEMIA , *CANCER radiotherapy - Abstract
From surviving fraction to tumour curability, definitions of tumour radioresistance may vary depending on the view angle. Yet, mechanisms of radioresistance have been identified and involve tumour-specific oncogenic signalling pathways, tumour metabolism and proliferation, tumour microenvironment/hypoxia, genomics. Correlations between tumour biology (histology) and imaging allow theragnostic approaches that use non-invasive biological imaging using tracer functionalization of tumour pathway biomarkers, imaging of hypoxia, etc. Modelling dose prescription function based on their tumour radio-resistant factor enhancement ratio, related to metabolism, proliferation, hypoxia is an area of investigation. Yet, the delivery of dose painting by numbers/voxel-based radiotherapy with low lineal energy transfer particles may be limited by the degree of modulation complexity needed to achieve the doses needed to counteract radioresistance. Higher lineal energy transfer particles or combinations of different particles, or combinations with drugs and devices such as done with radioenhancing nanoparticles may be promising. [ABSTRACT FROM AUTHOR]
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- 2020
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15. Interest of positron-emission tomography and magnetic resonance imaging for radiotherapy planning and control.
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Créhange, G., Soussan, M., Gensanne, D., Decazes, P., Thariat, J., and Thureau, S.
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COMPUTED tomography , *POSITRON emission tomography , *MAGNETIC resonance imaging , *RADIOTHERAPY treatment planning , *IMAGE registration - Abstract
Computed tomography (CT) in the treatment position is currently indispensable for planning radiation therapy. Other imaging modalities, such as magnetic resonance imaging (MRI) and positron emission-tomography (PET), can be used to improve the definition of the tumour and/or healthy tissue but also to provide functional data of the target volume. Accurate image registration is essential for treatment planning, so MRI and PET scans should be registered at the planning CT scan. Hybrid PET/MRI scans with a hard plane can be used but pose the problem of the absence of CT scans. Finally, techniques for moving the patient on a rigid air-cushioned table allow PET/CT/MRI scans to be performed in the treatment position while limiting the patient's movements exist. At the same time, the advent of MRI–linear accelerator systems allows to redefine image-guided radiotherapy and to propose treatments with daily recalculation of the dose. The place of PET during treatment remains more confidential and currently only in research and prototype status. The same development of imaging during radiotherapy is underway in proton therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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16. Imaging issues specific to hadrontherapy (proton, carbon, helium therapy and other charged particles) for radiotherapy planning, setup, dose monitoring and tissue response assessment.
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Thariat, J., Hérault, J., Beddok, A., Feuvret, L., Dauvergne, D., Gérard, M., Balosso, J., Noël, G., and Valable, S.
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HELIUM , *RADIOTHERAPY , *COMPUTED tomography , *LINEAR energy transfer , *PROTONS , *ONLINE monitoring systems - Abstract
Imaging is critical to each step of precision radiation therapy, i.e. planning, setup, delivery and assessment of response. Hadrontherapy can be considered to deliver more precise dose distribution that may better spare normal tissues from intermediate low doses of radiation. In addition, hadrontherapy using high linear energy transfer ions may also be used for dose escalation on biological target volumes defined by functional imaging. However, the physical characteristics of hadrontherapy also make it more demanding in terms of imaging accuracy and image-based dose calculation. Some of the developments needed in imaging are specific to hadrontherapy. The current review addresses current status of imaging in proton therapy and the drawbacks of photon-based imaging for hadrons. It also addresses requirements in hadrontherapy planning with respect to multimodal imaging for proper target and organ at risk definition as well as to target putative radioresistant areas such as hypoxic ones, and with respect to dose calculation using dual energy CT, MR-proton therapy, proton radiography. Imaging modalities, such as those used in photon-based radiotherapy (intensity modulated and stereotactic radiotherapy), are somewhat already implemented or should be reaching "routine" hadrontherapy (at least proton therapy) practice in planning, repositioning and response evaluation optimizable within the next five years. Online monitoring imaging by PET, as currently developed for hadrontherapy, is already available. Its spatiotemporal limits restrict its use but similar to prompt gamma detection, represents an area of active research for the next 5 to 10 years. Because of the more demanding and specific dose deposit characteristics, developments image-guided hadrontherapy, such as specific proton imaging using tomography or ionoacoustics, as well as delivery with MR-proton therapy, may take another 10 years to reach the clinics in specific applications. Other aspects are briefly described such as range monitoring. Finally, the potential of imaging normal tissue changes and challenges to assess tumour response are discussed. [ABSTRACT FROM AUTHOR]
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- 2020
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17. Morphological and molecular criteria allow the identification of putative germ stem cells in a lophotrochozoan, the Pacific oyster Crassostrea gigas.
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Cherif-Feildel, Maëva, Kellner, Kristell, Goux, Didier, Elie, Nicolas, Adeline, Béatrice, Lelong, Christophe, and Heude Berthelin, Clothilde
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PACIFIC oysters , *STEM cells , *SOMATIC cells , *GAMETOGENESIS , *CELL nuclei , *GERM cells - Abstract
While our knowledge of bivalve gametogenesis recently progressed, data on early stages of gametogenesis remain to be developed, especially when dealing with germinal stem cells (GSC) and their niche in these organisms. Here, we wish to develop a strategy to identify putative GSC in Pacific oyster Crassostrea gigas based on morphological criteria combined with vasa marker expression. A histological quantitative approach, based on stereology, allowed us to identify two types of early germ cells in the germinal epithelium, one presenting round nuclei and the other irregular ones. Both early germ cell types present slightly condensed chromatin in nucleus, are vasa-positive and the Oyvlg (oyster vasa-like gene) expression in these cells is recorded throughout the whole gametogenesis process. The microenvironment of an early germ cell in oyster includes an associated somatic cell presenting an immunolabeling for BMP2/4 and a close myoid cell. In agreement with the GSC characteristics in other species, we postulate that putative germ stem cells in C. gigas correspond to the early germ cell type with irregular nucleus shape; those early germ cells with a round nucleus may consist in progenitors. [ABSTRACT FROM AUTHOR]
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- 2019
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18. Experimental soft‐sediment deformation caused by fluidization and intrusive ice melt in sand.
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Bertran, Pascal, Font, Marianne, Giret, Arnaud, Manchuel, Kevin, Sicilia, Deborah, and Eyles, Nick
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SAND , *ICE , *PORE water pressure - Abstract
Identifying the driving mechanisms of soft‐sediment deformation in the geological record is the subject of debate. Thawing of ice‐rich clayey silt above permafrost was proved experimentally to be among the processes capable of triggering deformation. However, previous work has failed so far to reproduce similar structures in sand. This study investigates fluidization and intrusive ice formation from soil models in the laboratory. Experimental conditions reproduce the growth of ice‐cored mounds caused by pore water pressure increase during freeze‐back of sand in a permafrost context. Excess pore water pressure causes hydraulic fracturing and the development of water lenses beneath the freezing front. Later freezing of the water lenses generates intrusive ice. The main structures consist of sand dykes and sills formed when the increase in pore water pressure exceeds a critical threshold, and soft‐sediment deformations induced by subsidence during ice melt. The combination of processes has resulted in diapir‐like structures. The experimental structures are similar to those described in Pleistocene sites from France. These processes constitute a credible alternative to the seismic hypothesis evoked to explain soft‐sediment deformation structures in other European regions subjected to Pleistocene cold climates. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Aluminium-based galvanic anode impacts the photosynthesis of microphytobenthos and supports the bioaccumulation of metals released.
- Author
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Levallois, Alexandre, Vivier, Baptiste, Caplat, Christelle, Goux, Didier, Orvain, Francis, Lebel, Jean-Marc, Claquin, Pascal, Chasselin, Léo, Basuyaux, Olivier, and Serpentini, Antoine
- Subjects
- *
ABSORPTION cross sections , *ANODES , *BIOACCUMULATION , *SUBMERGED structures , *BIOLOGICAL membranes , *ALUMINUM foam , *PHOTOSYNTHESIS , *ALUMINUM-zinc alloys - Abstract
• The microphytobenthos incorporated aluminium from the galvanic anode. • Biomass was affected by a realistic Al concentration in contaminated coastal waters. • Photosynthetic parameters were negatively affected as productivity and F v /. F m • Extracellular polymeric substances were affected by anode metals. Very few studies have looked at the potential biological effects of degradation products of galvanic anodes particularly on primary producers which are central to food webs in marine ecosystems. The galvanic anode cathodic protection system (GACP) is widely used to protect submerged metallic structures from corrosion. Aluminium (Al) and zinc (Zn) are the main constituents of galvanic anodes and are therefore released in the marine environment by oxidation process to form ions or oxy-hydroxides. The main objective of our study was to evaluate the effects of the metals released from an aluminium-based galvanic anode on microphytobenthos performance in term of biofilm growing through the analysis of photosynthetic parameters, the determination of chlorophyll and extracellular polymeric substances (EPS). The bioaccumulation of Al and Zn were measured in the microphytobenthic compartment collected at the surface of polyvinyl chloride (PVC) plates exposed during 13 days to seawaters enriched in different concentrations of metals released from dissolution of one anode. Determination of bioconcentration factors confirmed that the microphytobenthos has incorporated Al. A significative effect was observed on the Chl a concentration for the higher tested concentration ([Al] = 210.1 ± 60.2 µg L −1; [Zn] = 20.2 ± 1.4 µg L −1). The seawater exposed to the anode affected the MPB productivity (E T R I I m a x ) with consequences on acclimatation light (Ek), absorption cross section of PSII (σ P I I), F v / F m and NPQ. Regarding the EPS production, the anode degradation presented an impact on high and low molecular weight of both carbohydrates and protein fractions of microphytobenthos suggesting that EPS play an essential role in sequestering metal contaminants to maintain the integrity of the biological membranes and the functionality of the cellular organelles. The accumulation of Al released by GACP in microphytobenthos cells could lead to physiologic problems in photosynthetic organisms. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Adaptive observer design with heat PDE sensor.
- Author
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Ahmed-Ali, Tarek, Giri, Fouad, Krstic, Miroslav, Burlion, Laurent, and Lamnabhi-Lagarrigue, Françoise
- Subjects
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PARAMETER estimation , *STATE estimation in electric power systems , *KALMAN filtering , *ADAPTIVE control systems , *PARABOLIC differential equations - Abstract
The problem of state and parameter estimation is addressed for systems with cascade structure including finite-dimensional dynamics followed in series with infinite-dimensional dynamics. The formers are captured through an ODE that is state- and parameter-affine. The latter, referred to as sensor dynamics, are represented by a diffusion parabolic PDE. Both equations are subject to parameter uncertainty. Furthermore, the connection point between the ODE and the PDE blocs is not accessible to measurements. The aim is to get online estimates of all inaccessible states and unknown parameters of both the ODE and the PDE subsystems. This observation problem is dealt with by combining the backstepping design method and the extended Kalman observer approach. The obtained adaptive observer is shown to be exponentially convergent under an ad-hoc persistent excitation condition. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
21. Effects of chronic exposure of metals released from the dissolution of an aluminium galvanic anode on the Pacific oyster Crassostrea gigas.
- Author
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Levallois, Alexandre, Caplat, Christelle, Basuyaux, Olivier, Lebel, Jean-Marc, Laisney, Antoine, Costil, Katherine, and Serpentini, Antoine
- Subjects
- *
PACIFIC oysters , *ANODES , *SUBMERGED structures , *METALS , *ALUMINUM - Abstract
• Oysters were exposed for three months to three concentrations of aluminum obtained with an electrochemical experimental device. • Oysters bioaccumulated more zinc than aluminum, even if it was present in greater concentrations. • Moreover, exposure time did not influence the bioaccumulation of aluminum in contrast to zinc. • A battery of biomarkers were studied and some biological effects were observed especially at the highest concentration. Among the anthropogenic sources releasing metallic species into the marine environment, the galvanic anode cathodic protection system (GACP) is widely used to protect submerged metallic structures from corrosion. Galvanic anodes are an alloy of metals of which the main component is aluminum or zinc. Very few studies were performed to study their potential biological effects. We investigated the chronic toxicity of an aluminum-based galvanic anode on the Pacific oyster, Crassostrea gigas. Oysters were exposed for 84 days to three concentrations of aluminum (50, 100 and 300 µg L−1) obtained with an electrochemical experimental device simulating the dissolution of a galvanic anode. At different exposure times, we studied a battery of biomarkers of the immune system, reproductive parameters and the metabolic state of the oysters. Results demonstrated a sensitivity of oysters at the highest concentration and some biological effects were observed especially for the malondialdehyde content in the digestive gland after 84 days of exposure. In addition to these biomarkers, the bioaccumulation of the different metals composing the anode was measured in oysters' tissues. Bivalves bioaccumulated more zinc than aluminum, even if aluminium was present in greater concentrations during exposures. Moreover, exposure time did not influence the bioaccumulation of aluminum in contrast to zinc. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Genetic Determinism of Primary Early-Onset Osteoarthritis.
- Author
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Aury-Landas, Juliette, Marcelli, Christian, Leclercq, Sylvain, Boumédiene, Karim, and Baugé, Catherine
- Subjects
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OSTEOARTHRITIS diagnosis , *OSTEOARTHRITIS treatment , *OSTEOARTHRITIS , *EXOMES , *NUCLEOTIDE sequence , *GENETIC mutation , *GENETICS - Abstract
Osteoarthritis (OA) is the most common joint disease worldwide. A minority of cases correspond to familial presentation characterized by early-onset forms which are genetically heterogeneous. This review brings a new point of view on the molecular basis of OA by focusing on gene mutations causing early-onset OA (EO-OA). Recently, thanks to whole-exome sequencing, a gain-of-function mutation in the TNFRSF11B gene was identified in two distant family members with EO-OA, opening new therapeutic perspectives for OA. Indeed, unraveling the molecular basis of rare Mendelian OA forms will improve our understanding of molecular processes involved in OA pathogenesis and will contribute to better patient diagnosis, management, and therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
23. Distinct psychological profiles among college students with substance use: A cluster analytic approach.
- Author
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Lannoy, Séverine, Mange, Jessica, Leconte, Pascale, Ritz, Ludivine, Gierski, Fabien, Maurage, Pierre, and Beaunieux, Hélène
- Subjects
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COLLEGE students , *UNITARY groups , *PSYCHOLOGICAL factors , *SELF-esteem , *PUBLIC health , *IMPULSE (Psychology) , *ADAPTABILITY (Personality) , *SUBSTANCE abuse , *MOTIVATION (Psychology) , *BEHAVIOR , *STUDENTS , *ALCOHOL drinking , *UNIVERSITIES & colleges , *ANXIETY - Abstract
Substance use in youth is a central public health concern, related to deleterious consequences at psychological, social, and cognitive/cerebral levels. Previous research has identified impulsivity and consumption motives as key factors in the emergence of excessive substance use among college students. However, most studies have focused on a specific substance and have considered this population as a unitary group, ignoring the potential heterogeneity in psychological profiles. We used a cluster analytic approach to explore the heterogeneity in a large sample (N = 2741) of substance users (i.e., tobacco, alcohol, cannabis, ecstasy, cocaine, heroin) on impulsivity and consumption motives. We identified four clusters: The first two clusters, associated with good self-esteem, low anxiety, and moderate substance use, were respectively characterized by low impulsivity and consumption motives (Cluster 1) and by high social and enhancement motives without marked impulsivity (Cluster 2). The two other clusters were conversely related to low self-esteem and high anxiety, and characterized by high consumption motives (particularly conformity) together with elevated urgency (Cluster 3) and by globally increased impulsivity and consumption motives (Cluster 4). These two clusters were also associated with higher substance use. These results highlight the existence of distinct psychological profiles of substance users and underline the need to develop targeted prevention and intervention programs (e.g., focusing on the specific impulsivity facets and consumption motives presented by each subgroup). Based on these findings, we also suggest extending the exploration of distinct profiles of substance users by targeting other psychological variables (e.g., self-esteem). [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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24. The typology of slope slides of the cliff coast of Safi-Morocco, and the role of the clay layer in triggering failure.
- Author
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Ayt Ougougdal, Mohamed, Chaibi, Mohamed, Mercier, Denis, Maquaire, Olivier, Maanan, Mohamed, Costa, Stéphane, Charif, Abdessamad, and Ragaru, Etienne
- Subjects
- *
CLAY , *PARTICLE size distribution , *ROCKFALL , *LITTORAL zone , *CLIFFS , *LANDSLIDE hazard analysis , *SLOPE stability - Abstract
The littoral zone of the Safi coastline is characterised by different geomorphological forms of coastal cliffs cutting into alternating layers of clay and limestone outcrops. The cliffs undergo a wide range of erosional processes with landslides as the most significant mode of recession. A classification of these landslides was made using the typology of the mechanisms, materials and the state of activity. The cliff movements are triggered at the clay level, thus, it is necessary to determine their physical and mechanical characteristics in order to describe their geomechanical behaviour. The finer grain size distribution of the matrix reveals that the clays are misclassified and are ranging as silty clay loam. The Atterberg limits classify this formation as silt or clay of medium plasticity. The proportion of clay, the lithostatic pressure, and the slope are discussed as explanatory variables and expressed as indices. These measurable and descriptive geomorphological parameters can be used to explain the distribution of landslides, especially the rotational type. Statistical correlation in association with rotational slips indicates that the zones with high lithostatic pressure and significant value of the clay index are most affected by these instabilities. • The cliff coastline of Safi (Morocco) are composed of Jurassic, Cretaceous and Plio-Quaternary rocks. • Four landslides types are affecting these cliffs : rock falls, toppling, translational landslides, and rotational landslides. • Clays are, in presence of water, the trigger element of these landslides. The rotational ones are the most important. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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