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The Thoracic Absorption Dose and Secondary Tumor Risk Caused by Different Imaging Methods in Image‐Guided Particle Radiotherapy
No full textInternational audienceBackground: Image-guided radiation therapy uses imaging methods such as CBCT to effectively improve treatment precision. Kilovoltage-imaging technology provides high soft tissue contrast at low doses, whereas megavoltage-imaging technology better displays deep and bony structures at high doses. Proton therapy is more sensitive to tissue density and positional accuracy, so it requires more stringent image guidance and higher precision than traditional X-ray therapy.Objective: This study evaluates radiation doses from CBCT systems (TrueBeam, Halcyon, ProBeam, TOMO) in both adult and pediatric phantoms, measuring dose variations and predicting secondary tumor risks using a radiobiological model.Methods: Absorbed doses in organs of adult and pediatric phantoms were measured with OSLDs across imaging systems. The risk of secondary tumors was estimated using the BEIR VII model.Results: Halcyon 2.0 and TOMO's MV-level imaging systems showed significantly higher doses than KV-level systems. Pediatric patients received 2-3 times higher doses than adults. In KV-level imaging, Halcyon 2.0 resulted in the highest lung tissue dose in both age groups (17.464 mGy for pediatric, 9.109 mGy for adult), whereas ProBeam had the lowest (6.844 and 4.073 mGy, respectively). The lifetime attributable risk for lung cancer correlated with the dose, with higher risks in children.Conclusions: Higher radiation doses lead to greater secondary tumor risk, with the risk being more pronounced in pediatric patients. Continuous thoracic CBCT can deliver up to 1 Gy in thoracic organs, posing a significant risk of secondary tumors, especially in younger patients. Careful consideration of this risk is essential in treatment planning
La Communauté autonome basque et la gouvernance multiniveau dans l’Arc Atlantique : tensions et stratégies
No full textInternational audienceThis article explores the dynamics of multi-level governance in the Atlantic Arc, focusing on the strategy of the Basque Autonomous Community (BAC). Drawing on the theories of multi-level governance (Hooghe & Marks) and soft planning (Faludi), the study investigates how the BAC uses European frameworks such as INTERREG, TEN-T corridors, and the Atlantic macro-region to overcome institutional rigidity and defend its local priorities. Through the lens of strategic instrumentalization (Jacquot & Woll), the article demonstrates how the BAC leverages these European frameworks to balance transnational ambitions (macro-region) and territorial pragmatism (Atlantic Corridor). Furthermore, the reinterpretation of the Atlantic Arc as borderscapes (Rajaram & Grundy-Warr) reveals the tensions between institutional innovation and state-dominated governance, which hinder deeper transnational integration. In conclusion, the study highlights the complexity of regional strategies within a shifting European framework and emphasizes the need for enhanced dialogue across local, national, and transnational scales to achieve coherent governance in the Atlantic Arc.Cet article analyse les dynamiques de la gouvernance multiniveau dans l’Arc Atlantique, en se concentrant sur la stratégie de la Communauté autonome basque (CAB). En mobilisant les théories de la gouvernance multiniveau (Hooghe & Marks) et de l’aménagement souple (Faludi), l’étude examine comment la CAB utilise les instruments européens tels qu’INTERREG, les Réseaux transeuropéens de transport (RTE-T) et la macro-région atlantique pour surmonter les rigidités institutionnelles et défendre ses priorités locales. En s’appuyant sur le concept d’usages de l’Europe (Jacquot & Woll), l’article montre comment la CAB manipule ces cadres européens pour articuler ambitions transnationales (macro-région) et pragmatisme territorial (corridor Atlantique). En outre, la redéfinition de l’Arc Atlantique en tant que borderscape (Rajaram & Grundy-Warr) illustre les tensions entre innovation institutionnelle et domination étatique, freinant l’intégration transnationale. En conclusion, l’étude souligne la complexité des stratégies régionales dans un cadre européen en mutation, et la nécessité d’un dialogue renforcé entre les échelles locales, nationales et transnationales pour une gouvernance cohérente de l’Arc Atlantique
A l'école althussérienne: Aperçus d'une (non) philosophie de l'éducation
No full textInternational audienceLorsque Althusser et certains de ses anciens élèves, après avoir entrepris de relire Marx, observent la force de la colère sociale qui s’exprime à la fin des années 1960, ils décident de s’intéresser à une question qu’ils ne peuvent plus éviter : l’éducation. Il s’agit alors, pour Althusser et ses collaborateurs, dont notamment Etienne Balibar, Pierre Macherey, Christian Baudelot, Michel Tort et Roger Establet, de réfléchir, en marxiste et parfois en philosophe, à ces questions tout en produisant une analyse de la situation, avant peut-être de rencontrer les forces vives mobilisées dans le champ éducatif et scolaire. Au bout de quelques mois, ce projet collectif imprévu donne lieu à plusieurs productions stimulantes avant que les protagonistes de cette histoire ne suivent chacun leur propre itinéraire intellectuel et académique, sonnant le glas de cette aventure consacrée à la critique spécifique de l’École en tant qu’Appareil Idéologique d’État. Cette expérience de pensée qui s’est donnée à voir comme une non philosophie de l’éducation constitue aujourd’hui l’obscur de la philosophie de l’éducation contemporaine.Cet ouvrage revient sur l’atelier virtuel dans lequel cette forme de pensée s’est construite, mais il aborde également les obstacles rencontrés et les défis auxquels elle a dû faire face pour produire une nouvelle forme de connaissance des faits éducatifs et concevoir une autre forme d’intervention philosophique. Si cette étude montre les limites de l’entreprise en jeu dans cette aventure, elle revient également sur sa profonde singularité.Cet ouvrage se propose de faire (re)découvrir un épisode oublié de la vie intellectuelle française lorsque l’althussérisme a rencontré une question vive, l’éducation, dans le contexte dans années 1960 et 1970, et tenté de réfléchir, à partir du marxisme, aux questions éducatives et à la place de l’École dans la société française
Un cas d’hypernatrémie sévère chez un patient cachectique dans un contexte d’hospitalisation pour une pneumopathie à pneumocoque
No full textInternational audienceUn homme de 65 ans, aux antécédents d’accidents vasculaires cérébraux séquellaires et de pneumopathie d’inhalation, est hospitalisé pour un nouvel épisode de pneumopathie à pneumocoque. Aux urgences, le bilan biologique révèle une hypernatrémie sévère associée à de nombreuses autres anomalies biologiques, avec une normalisation soudaine de la natrémie
Metal-centred states control carrier lifetimes in transition metal oxide photocatalysts
No full textInternational audienceEfficient sunlight-to-energy conversion requires materials that can generate long-lived charge carriers upon illumination. However, the targeted design of semiconductors possessing intrinsically long lifetimes remains a key challenge. Here using a series of transition metal oxides, we establish a link between carrier lifetime and electronic configuration in transition metal-based semiconductors. We identify a subpicosecond relaxation mechanism via metal-centred ligand field states that compromise quantum yields in open d-shell transition metal oxides (for example, Fe2O3, Co3O4, Cr2O3 and NiO), which is more reminiscent of molecular complexes than crystalline semiconductors. We found that materials with spin-forbidden ligand field transitions could partially mitigate this relaxation pathway, explaining why Fe2O3 achieves higher photoelectrochemical activity than other visible light-absorbing transition metal oxides. However, achieving high yields of long-lived charges requires transition metal oxides with d0 or d10 electronic configurations (for example, TiO2 and BiVO4), where ligand field states are absent. These trends translate to transition metal-containing semiconductors beyond oxides, enabling the design of photoabsorbers with better-controlled recombination channels in photovoltaics, photocatalysis and communication devices
Ultrafast charge-transfer-induced spin transition in cobalt-tungstate molecular photomagnets
No full textInternational audienceIn materials exhibiting photoinduced phase transitions, and in which both charge transfer and spin transitions occur, there has long been a debate about which process drives the phase transition. Herein, we present experimental evidence supporting an optically charge-transfer-induced spin transition (CTIST) process, as demonstrated through femtosecond optical spectroscopy in two-dimensional cyanido-bridged cobalt-tungstate photomagnets. Optical and magnetic studies revealed that the photoexcitation of the ground low-temperature (LT) CoIIILS-WIV state leads to a photoinduced phase transition towards the CoIIHS-WV state, which is similar to the high temperature (HT) state. Ultrafast spectroscopy further indicates that this optical excitation of the intermetallic W-to-Co charge-transfer band produces a transient photoexcited (PE) CoIILS-WV state, which decays within 130 fs through a spin transition towards the CoIIHS-WV state. Here we show that the CTIST dynamics corresponds to the CoIIILS-WIV (LT) → CoIILS-WV (PE) → CoIIHS-WV (HT) sequence. The present work sheds a new light on understanding optical dynamics underlying the photoinduced phase transitions
Safety of in-bag morcellation during laparoscopic myomectomy and hysterectomy: a systematic review and meta-analysis
No full textInternational audienceObjective: To systematically evaluate the outcomes of in-bag versus no-bag morcellation during laparoscopic myomectomy and hysterectomy, focusing on safety.Data sources: Searches were conducted in Cochrane Library, Embase, and PubMed, covering studies from inception up to January 31, 2024.Methods of study selection: Inclusion of studies on females undergoing laparoscopic myomectomy and/or hysterectomy with in-bag morcellation, excluding series with fewer than 10 patients.Tabulation, integration and results: Data were synthesized using meta-analysis techniques, with sensitivity analyses for rare events, focusing on intraoperative complications (i.e. a composite outcome including conversion to laparotomy, bowel injury or, accidental injury to any viscus injury or vessel). The secondary outcomes include presence of parasitic fibroma, fragment of myometrium/uterus, blood transfusion, bleeding > 500mL, total operative time, postoperative length of stay, postoperative pain, conversion to laparotomy, postoperative complications and cost. From 1,970 published studies, we included 20 trials, enrolling 5,505 women in the in-bag and 37,283 women in the no-bag group. We included 9 trials in each subgroup: myomectomy and hysterectomy, enrolling 767 and 4678 women in the in-bag; 830 and 36380 women in the no-bag groups, respectively. We observed increased intraoperative complications compared to no-bag morcellation (OR 1.45, 95% CI 1.11;1.89) with a null heterogeneity (I²= 0%). The hysterectomy subgroup analysis showed a significant association between bag and intraoperative complications (OR 1.47, 95% CI 1.12;1.93) but not myomectomy (OR 1.00, 95% CI 0.29;3.43). We did not have enough information to conclude about the presence of parasitic fibroma, fragment of myometrium and costs. No statistical differences were observed concerning the other secondary outcomes.Conclusions: The use of containment bags in morcellation may increase the risk of intra-operative complications, particularly in case of hysterectomy. However, these events might not be directly related to bag use and could represent confounding factors. Further studies are needed to investigate in-bag morcellation.Registration: CRD42023478908 on the International Prospective Register of Systematic reviews. Registered November 19, 2024
Development of co-sputtered amorphous Ge–Bi–Se films for nonlinear infrared photonic applications
No full textInternational audienceRF magnetron cosputtered amorphous Ge–Bi–Se films were fabricated using polycrystalline GeSe2 and Bi2Se3 targets. Their structural, linear, and nonlinear optical properties were studied to understand compositional influence for future photonic applications. A broader Ge–Bi–Se amorphous region with a noticeably high bismuth atomic percentage (up to at % Bi = 36%) is observed using this deposition method compared to ≤16 at % in the conventional Ge20Se80–xBix bulk glass synthesis [Ikari, T. Phys. Rev. B 1993, 47(9), 4984]. The structural characteristics of the cosputtered films were analyzed using Raman spectroscopy, where increasing bismuth concentration shifted all vibrational bands to the lower energy side with reduced intensity. A decrease in optical band gap energy values from 2.04 (±0.02) eV (Bi atom % = 0) to 0.73 (±0.02) eV (Bi atom % = 36) and the corresponding increase in refractive index value n from 2.41 (±0.01) to 4.09 (±0.01) at telecommunication wavelength indicate the strong influence of bismuth on the optical properties of the films. Third-order nonlinear optical parameters were calculated from linear parameters using semiempirical equations and Sheik-Bahae formalism in order to allow their prediction according to the film composition and taking into account the wavelength of use. Following these simulations, which enabled the selection of promising compositions in terms of optical nonlinearity applications, this work also focused on demonstrating the feasibility of manufacturing ridge waveguides from these cosputtered films by RF magnetron using dry etching with the aim of offering Ge–Bi–Se-based integrated optical circuits
Life Cycle Assessment of an ultramicroelectrode array sensor for trace metal measurement in water, a cradle-to-gate approach
No full textInternational audienceThe environmental impact of manufacturing an electrochemical measurement system is evaluated using Life Cycle Assessment (LCA). This study focuses on identifying the most impactful materials and processes with the aim of eco-design on manufacturing an ultramicroelectrode array sensor: reducing environmental impacts through process modification, material changes and reducing electricity consumption. A cradle-to-gate approach is used. The results highlight that metal (i.e., gold and titanium) and insulator deposition are the most impactful steps, primarily due to high electricity consumption
An Algebraic Point of View on the Generation of Pairing-Friendly Curves
No full textInternational audienceIn 2010, Freeman, Scott, and Teske published a well-known taxonomy compiling the best known families of pairing-friendly elliptic curves. Since then, the research effort mostly shifted from the generation of pairing-friendly curves to the improvement of algorithms or the assessment of security parameters to resist the latest attacks on the discrete logarithm problem. Consequently, very few new families were discovered. However, the need of pairing-friendly curves of prime order in some new applications such as SNARKs has reignited the interest in the generation of pairing-friendly curves, with the hope of finding families similar to the one discovered by Barreto and Naehrig.Building on the work of Kachisa, Schaefer, and Scott, we show that some particular elements of quadratic extensions of a cyclotomic field generate families of pairing-friendly curves with small parameters. By exhaustive search among these elements, we discovered new families of curves of embedding degree , , and . We provide an open-source SageMath implementation of our technique. We obtain curves of cryptographic size from our new families and we give a proof-of-concept SageMath implementation of a pairing on some new curves