311 research outputs found

    Building up the Future of Colonoscopy – A Synergy between Clinicians and Computer Scientists

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    Recent advances in endoscopic technology have generated an increasing interest in strengthening the collaboration between clinicians and computers scientist to develop intelligent systems that can provide additional information to clinicians in the different stages of an intervention. The objective of this chapter is to identify clinical drawbacks of colonoscopy in order to define potential areas of collaboration. Once areas are defined, we present the challenges that colonoscopy images present in order computational methods to provide with meaningful output, including those related to image formation and acquisition, as they are proven to have an impact in the performance of an intelligent system. Finally, we also propose how to define validation frameworks in order to assess the performance of a given method, making an special emphasis on how databases should be created and annotated and which metrics should be used to evaluate systems correctly

    A benchmark for endoluminal scene segmentation of colonoscopy images

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    Colorectal cancer (CRC) is the third cause of cancer death worldwide. Currently, the standard approach to reduce CRC-related mortality is to perform regular screening in search for polyps and colonoscopy is the screening tool of choice. The main limitations of this screening procedure are polyp miss rate and the inability to perform visual assessment of polyp malignancy. These drawbacks can be reduced by designing decision support systems (DSS) aiming to help clinicians in the different stages of the procedure by providing endoluminal scene segmentation. Thus, in this paper, we introduce an extended benchmark of colonoscopy image segmentation, with the hope of establishing a new strong benchmark for colonoscopy image analysis research. The proposed dataset consists of 4 relevant classes to inspect the endoluminal scene, targeting different clinical needs. Together with the dataset and taking advantage of advances in semantic segmentation literature, we provide new baselines by training standard fully convolutional networks (FCNs). We perform a comparative study to show that FCNs significantly outperform, without any further postprocessing, prior results in endoluminal scene segmentation, especially with respect to polyp segmentation and localization

    A structure from the sixth millennium cal BC with no artifactual content at San Quirce (Palencia, Spain): a multidisciplinary study

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    During the course of the excavations of the San Quirce open-air archaeological site in Spain, an unusual negative structure was identified in the Holocene level dated ca. sixth millennium cal BC. A fire pit alongside a single post-hole and intense fire-burning activity was recorded. Yet, the most striking feature of the structure is the absence of any artifactual or faunal record associated to it, something without a known archaeological parallel. Its interpretation represents an archaeological challenge addressed through a multidisciplinary approach including geoarchaeological, palaeobotanical techniques and experimental archaeology. Fifteen stratigraphically distinguishable combustion events showing a diachronic fire record, the significant structure’s dimensions and particularly the post-hole, indicate its anthropic origin. Archaeomagnetic and micromorphological data allowed reconstructing and temporally sequencing some formation and post-depositional processes, some involving water flows. Maximum heating temperatures between 480 and 525 °C were determined in one of the combustion features studied. The identification of grassy tufts would suggest a seasonal settlement of the site. We cannot yield a definite explanation for the artifactual absence, but the available data and an experimental archaeology recreation suggest that the structure could be used as a small hut/open-air bivouac, over which short-lived occupations were repeatedly carried out.Junta de Castilla y León (project BU235P18) with also FEDER founding

    Radon (222Rn) outgassing in San Juan volcanic tubes during the Cumbre Vieja eruption 2021, and preliminary values in the newly volcanic tubes.

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    During the eruption at Cumbre Vieja ridge (La Palma, Canary Islands, 2021) a radon (222Rn) detector (CORENTIUM Pro alpha particles counter) was emplaced inside the Las Palomas lava tube (San Juan eruption, 1949). In addition, a CO2 meter logger was emplaced to determine relationships between the 2021 eruption and radon plus CO2 inner fluxes. There is a geostructural relationship between the 1949 and 2021 eruptions, probably connected by a previous fault, shown the volcanic vents¿ alignment trending NW-SE. In October 2021, the radon and CO2 loggers were moved to the upper part of the lava tube, in the San Juan volcanic vent (Llano del Banco hollow dyke). Once the eruption ended (in early 2022) both loggers were placed in one newly formed lava tube, and data will be collected in February 2023. Preliminary results show daily average radon values ranging between 2 - 9 Bq/m3, although sporadic peaks of about 270 and 650 Bq/m3 were recorded related to volcano-tectonic earthquakes and volcanic intensity. In general, basaltic eruptions of alkaline affinity show low radon values due to the low concentration in the magma body of uranium and related chemical elements (Th, Ra, etc.). Geochemical analysis of emitted lavas shows a U concentration of about 1 to 5 ppm (g/g) and Th 9.5 ppm. Summer values of Rn increased up to 3 KBq/m3, related to the climate conditions instead of volcanic activity

    Imagen corporal en niños obesos: efectos producidos por un programa de ejercicio físico

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    P. 149-162La autopercepción de la imagen corporal en niños obesos resulta importante, puede generar comportamientos conducentes a aislamiento social, e inducir un aumento en la ingesta de alimentos. El objetivo del estudio fue determinar los cambios producidos en el grado de satisfacción con la imagen corporal y las variaciones en indicadores antropométricos de los infantes del estado de Sonora, México, después de participar en un programa de 40 sesiones de ejercicio físico con un gasto calórico promedio de 267 Kcal por sesión. Se reclutó a 119 niños de 8 a 11 años con índice de masa corporal (IMC) de 26.59 ± 4.2 (kg/m2). Se evaluaron antes y después de la intervención mediante el test de Satisfacción con la Imagen Corporal (SIC). Los resultados con cambios significativos (p ≤ 0.05) entre pre-test y post-test se encuentran en el peso y la talla. Se observan además cambios significativos en la autoimagen en 15 partes de los segmentos corporales evaluados principalmente abdomen, pecho, muslos, glúteos, cintura y cadera en la totalidad de los niños del grupo experimental. Los resultados concluyen que el ejercicio físico a pesar de no producir cambios significativos en el IMC puede modificar positivamente la percepción de la imagen corporalS

    Alkaline activation of ceramic waste materials

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    Ceramic materials represent around 45 % of construction and demolition waste, and originate not only from the building process, but also as rejected bricks and tiles from industry. Despite the fact that these wastes are mostly used as road sub-base or construction backfill materials, they can also be employed as supplementary cementitious materials, or even as raw material for alkali-activated binders This research aimed to investigate the properties and microstructure of alkali-activated cement pastes and mortars produced from ceramic waste materials of various origins. Sodium hydroxide and sodium silicate were used to prepare the activating solution. The compressive strength of the developed mortars ranged between 22 and 41 MPa after 7 days of curing at 65 C, depending on the sodium concentration in the solution and the water/binder ratio. These results demonstrate the possibility of using alkaliactivated ceramic materials in building applications.The authors are grateful to the Spanish Ministry of Science and Innovation for supporting this study through Project GEOCEDEM BIA 2011-26947, and also to FEDER funding. They also thank Universitat Jaume I for supporting this research through Lucia Reig's granted research stay.Reig Cerdá, L.; Mitsuuchi Tashima, M.; Soriano, L.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Paya Bernabeu, JJ. (2013). Alkaline activation of ceramic waste materials. Waste and Biomass Valorization. 4:729-736. https://doi.org/10.1007/s12649-013-9197-zS7297364Puertas, F., García-Díaz, I., Barba, A., Gazulla, M.F., Palacios, M., Gómez, M.P., Martínez-Ramírez, S.: Ceramic wastes as alternative raw materials for Portland cement clinker production. 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Sci. 42(9), 2917–2993 (2007)Bernal, S.A., Rodríguez, E.D., de Gutiérrez, R.M., Provis, J.L., Delvasto, S.: Activation of metakaolin/slag blends using alkaline solutions based on chemically modified silica fume and rice husk ash. Waste Biomass Valor. 3, 99–108 (2012)Fernández-Jiménez, A., Palomo, A., Criado, M.: Microstructure development of alkali-activated fly ash cement: a descriptive model. Cement Concrete Res 35, 1204–1209 (2005)Payá, J., Borrachero, M.V., Monzó, J., Soriano, L., Tashima, M.M.: A new geopolymeric binder from hydrated-carbonated cement. Mater. Lett. 74, 223–225 (2012)Kourti, I., Amutha-Rani, D., Deegan, D., Boccaccini, A.R., Cheeseman, C.R.: Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues. J. Hazard. 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Descomposición durante la cocción del carbonato cálcico contenido en el soporte crudo de los azulejos. Tesis de doctorado, Departamento de Ingeniería química, UJI (2005)Baronio, G., Binda, L.: Study of the pozzolanicity of some bricks and clays. Constr. Build. Mater. 11(1), 41–46 (1997)Zanelli, C., Raimondo, M., Guarini, G., Dondi, M.: The vitreous phase of porcelain stoneware: composition, evolution during sintering and physical properties. J. Non-Cryst. Solids 357, 3251–3260 (2011)Carty, W.M., Senapati, U.: Porcelain-raw materials, processing, phase evolution, and mechanical behaviour. J. Am. Ceram. Soc. 81(1), 3–20 (1998)ASCER, COACV, COPUT, ITC-AICE, WEBER ET BROUTIN – CEMARKSA: Guía Baldosa Guía de la baldosa cerámica. IVE: Conselleria d’Obres Públiques, Urbanisme i Transports, 4ª Ed. Valencia (2003)Khater, H.M.: Effect of calcium on geopolimerization of aluminosilicate wastes. J. Mater. Civ. 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    Vascular endothelial growth factor and its soluble receptor in systemic lupus erythematosus patients

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    Vascular endothelial growth factor (VEGF) is a major regulator of physiological and pathological angiogenesis. Its soluble receptor (sVEGFR) is a potent VEGF antagonist. Systemic lupus erythematosus (SLE) is an autoimmune disease with a diverse array of clinical manifestations that affect virtually any organ. We aimed to analyze the relationship of VEGF and sVEGFR with SLE disease-related features including disease activity, damage, and severity. Serum levels of VEGF165 isoform and sVEGFR (receptor 1) were assessed in 284 well-characterized patients with SLE. Linear regression analysis was performed to analyze the relationship of disease characteristics with both VEGF and sVEGFR. Patients with a disease damage index (SLICC score) equal to or greater than 1 had significantly elevated serum levels of VEGF and sVEGFR. Regarding disease-specific features, musculoskeletal manifestations were the disease feature most commonly associated with the upregulation of both VEGF and sVEGFR. SLE disease damage is associated with higher levels of VEGF and sVEGFR.Funding: This work was supported by a grant to I.F-A. from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016 and by Fondo Europeo de Desarrollo Regional—FEDER—(Fondo de Investigaciones Sanitarias, PI20/00084)

    In vivo computer-aided diagnosis of colorectal polyps using white light endoscopy

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    Background and study aims Artificial intelligence is currently able to accurately predict the histology of colorectal polyps. However, systems developed to date use complex optical technologies and have not been tested in vivo. The objective of this study was to evaluate the efficacy of a new deep learning-based optical diagnosis system, ATENEA, in a real clinical setting using only high-definition white light endoscopy (WLE) and to compare its performance with endoscopists. Methods ATENEA was prospectively tested in real life on consecutive polyps detected in colorectal cancer screening colonoscopies at Hospital Clínic. No images were discarded, and only WLE was used. The in vivo ATENEA's prediction (adenoma vs non-adenoma) was compared with the prediction of four staff endoscopists without specific training in optical diagnosis for the study purposes. Endoscopists were blind to the ATENEA output. Histology was the gold standard. Results Ninety polyps (median size: 5 mm, range: 2-25) from 31 patients were included of which 69 (76.7 %) were adenomas. ATENEA correctly predicted the histology in 63 of 69 (91.3 %, 95 % CI: 82 %-97 %) adenomas and 12 of 21 (57.1 %, 95 % CI: 34 %-78 %) non-adenomas while endoscopists made correct predictions in 52 of 69 (75.4 %, 95 % CI: 60 %-85 %) and 20 of 21 (95.2 %, 95 % CI: 76 %-100 %), respectively. The global accuracy was 83.3 % (95 % CI: 74%-90 %) and 80 % (95 % CI: 70 %-88 %) for ATENEA and endoscopists, respectively. Conclusion ATENEA can accurately be used for in vivo characterization of colorectal polyps, enabling the endoscopist to make direct decisions. ATENEA showed a global accuracy similar to that of endoscopists despite an unsatisfactory performance for non-adenomatous lesions
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