Fricke and polymer gel 2D dosimetry validation using Monte Carlo simulation

Complexity in modern radiotherapy treatments demands advanced dosimetry systems for quality control. These systems must have several characteristics, such as high spatial resolution, tissue equivalence, three-dimensional resolution, and dose-integrating capabilities. In this scenario, gel dosimetry has proved to be a very promising option for quality assurance. In this study, the feasibility of Fricke and polymer gel dosimeters suitably shaped in form of thin layers and optically analyzed by visible light transmission imaging has been investigated for quality assurance in external radiotherapy. Dosimeter irradiation was carried out with a 6-MV photon beam (CLINAC 600C). The analysis of the irradiated dosimeters was done using two-dimensional optical transmission images. These dosimeters were compared with a treatment plan system using Monte Carlo simulations as a reference by means of a gamma test with parameters of 1 mm and 2%. Results show very good agreement between the different dosimetric systems: in the worst-case scenario, 98% of the analyzed points meet the test quality requirements. Therefore, gel dosimetry may be considered as a potential tool for the validation of other dosimetric systems.Fil: Vedelago, José Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Chacón Obando, D.. Universidad Nacional. Physics Department; Costa Rica. Universidad Nacional de Córdoba; ArgentinaFil: Malano, Francisco Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Conejeros, R.. Servicio de Radioterapia, Icos. Temuco, Chile;Fil: Figueroa, R.. Universidad de la Frontera; ChileFil: Garcia, D.. Servicio de Imagenes por Resonancia Magnética; ChileFil: González, G.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Romero, Marcelo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Santibañez, M.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Velásquez, J.. Servicio de Radioterapia; ChileFil: Mattea, Facundo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valente, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad de La Frontera. Departamento de Ciencias Físicas; Chil

Exposure to community violence and Callous-Unemotional traits in young children: the role of positive parenting

IntroductionStudies regarding environmental contributions on callous-unemotional (CU) traits in children have informed about the protective role of positive parenting. However, it has not been explored whether findings from these studies -mostly conducted in High-Income Countries- can be generalised to Low-Middle-Income Countries (LMICs). Exposure to community violence is common in LMICs and is associated with emotional and behavioural problems in children. Therefore, it may represent an environmental risk factor for CU traits.ObjectivesThis prospective study explores whether positive parenting has a protective role in relation to CU traits in young Colombian children whose families have been exposed to community violence.MethodsWe assessed 235 families with children at age 3.5 years, from three contrasting regions of Colombia, using observations of mother-child interactions and maternal reports of community violence at ages 3.5 and 5.0 years.ResultsHierarchical multiple linear regression models indicated that maternal positivity at 3.5 years was associated with lower CU traits at age 5.0 years only in children of families exposed to community violence (interaction term p= .001). In the exposed group maternal positivity explained 10% of the variance (β= -.34, p= .001) with low positivity associated with elevated CU traits and high positivity with low CU traits. Maternal praise was not associated with CU traits. However, maternal negativity during play was associated with elevated CU traits as a main effect.ConclusionsBased on these findings, whether or not exposure to community violence is associated with elevated CU traits depends on maternal positivity, with low positivity creating vulnerability, and high positivity, resilience.DisclosureNo significant relationships.</jats:sec

Understanding Common Perceptions of the Drylands

Drylands occupy over 40% of the earth’s surface and are home to more than 2 billion people. Drylands are key to the food and nutritional security of the planet and vital to the economies and livelihoods of dryland inhabitants. Yet, drylands are commonly perceived as unproductive, economically inefficient and marginal lands where small-scale farmers and pastoralists practice environmentally degrading activities. Driven by inadequate understanding and misconceptions of the drylands, policy-makers devise inappropriate policies and interventions. The BRECcIA project developed an online Drylands Perceptions Survey to understand the perceptions of researchers, practitioners and policy makers working in the drylands of Kenya, Malawi and Ghana. This paper presents results from a pilot of 40 responses and is part of a wider ongoing study. Results show that many respondents subscribe to a number of common drylands statements or assumptions, although other statements are challenged and respondents disagree with the assumptions. In another set of cases, respondents had mixed views and a more nuanced picture emerged that is context dependent. Through the BRECcIA project, the survey findings are being used to shape the development of new and revised dryland training courses with a more critical policy and research focus for policy-makers, practitioners, researchers and students in Kenya

Prototipo a escala de un sistema de monitoreo de flujo en una línea de transporte de crudo y estado de un motor (encendido - apagado), mediante una aplicación Android

In this work give known the designed and implemented a monitoring system for the transmission of data, which takes a census flow through a pipe and the rpm of a motor (rpm), the data acquired from these measurements were transmitted to a Android device mobile technology for which an application visualize and store the data in real time on a developed database. This system showed great versatility, ease of operation and handling communication for data collection in real time to produce a record of the work carried out during the operation. Finally it was shown that the development of mobile applications become more comfortable and practical daily life of human beings, who are development tools booming, allowing successfully implemented in many sectors, in this case it was used for an application of commercial showing the potential of this technology and its vast applicability within society.Este articulo da a conocer el diseño e implementación de un sistema de monitoreo para la transmisión de datos en tiempo real, el cual sensa el flujo a través de una tubería y las revoluciones por minuto de un motor (rpm), los datos adquiridos de dichas mediciones fueron transmitidos a un dispositivo móvil con tecnología Android para lo cual se desarrolló una aplicación que visualizará y almacenará dichos datos en tiempo real en una base de datos. Este sistema presentó gran versatilidad, facilidad de operación y manejo en la comunicación para la toma de datos en tiempo real para elaborar un registro de la actividad realizada durante la operación. Finalmente se demostró que el desarrollo de aplicaciones móviles hacen más cómodo y práctico el diario vivir de los seres humanos, que son herramientas de desarrollo en auge, que permiten implementarse exitosamente en muchos sectores, en este caso se usó para una aplicación de carácter comercial mostrando el potencial de esta tecnología y su enorme aplicabilidad dentro de la sociedad

Association of hypomagnesemia and liver injury, role of gut-barrier dysfunction and inflammation: Efficacy of abstinence, and 2-week medical management in alcohol use disorder patients.

(1) We investigated the involvement of serum magnesium level in early alcoholic liver disease (ALD), gut barrier dysfunction, and inflammation in alcohol use disorder (AUD) patients; and lastly, the efficacy of 2-week abstinence and medical management to alleviate hypomagnesemia. (2) Forty-eight heavy drinking AUD patients (34 males (M)/14 females (F)) participated in this study. Patients were grouped by serum alanine aminotransferase (ALT) level (a marker of liver injury) as group 1 (Group 1 (Gr.1); ALT ≤ 40 U/L, 7M/8F, without any indication of early-stage ALD) and group 2 (Group 2 (Gr.2); ALT \u3e 40 U/L, 27M/6F or early-stage ALD). These patients were sub-divided within each group into patients with normal magnesium (0.85 and more mmol/L) and deficient magnesium (less than 0.85 mmol/L) levels. All participants were assessed at baseline (BL) and received standard medical management for 2 weeks with reassessment at the treatment end (2w). (3) Female participants of this study showed a significantly lower baseline level of magnesium than their male counterparts. Gr.2 patients showed a greater propensity in the necrotic type of liver cell death, who reported higher chronic and recent heavy drinking. Magnesium level improved to the normal range in Gr.2 post-treatment, especially in the hypomagnesemia sub-group (0.77 ± 0.06 mmol/L (BL) vs. 0.85 ± 0.05 mmol/L (2w), p = 0.02). In Gr.2, both apoptotic (K18M30) and necrotic (K18M65) responses were significantly and independently associated with inflammasome activity comprising of LBP (Lipopolysaccharide binding-protein) and TNFα (Tumor necrosis factor -α), along with serum magnesium. (4) In AUD patients with liver injury, 2-week medical management seems to improve magnesium to a normal level. This group exhibited inflammatory activity (LBP and TNFα) contributing to clinically significant hypomagnesemia. In this group, the level of magnesium, along with the unique inflammatory activity, seems to significantly predict apoptotic and necrotic types of hepatocyte death

PRODUTOS NATURAIS DE ALGAS MARINHAS PERTENCENTES À FAMÍLIA DICTYOTACEAE: POTENCIAIS BIOATIVOS ANTIFÚNGICO E ANTIOXIDANTE

Nos últimos anos, a pesquisa acerca do ambiente marinho tem aumentado, originando uma grande variedade de compostos com expressiva diversidade de atividades biológicas. Assim, algas marinhas configuram-se como fonte promissora de moléculas com interesse biotecnológico e farmacêutico. Algas pardas da família Dictyotaceae contribuem com uma importante porcentagem à diversidade estrutural de produtos naturais, que já demonstraram potencial antifúngico, antibacteriano, antiviral, além de exercerem múltiplas funções ecológicas nas algas. A maioria das espécies pertencem aos gêneros Dictyota, Lobophora e Padina, sendo conhecidas por produzirem diterpenos, esteróis, ácidos graxos e polissacarídeos. Levando em conta o exposto, o objetivo desta revisão é trazer um panorama atualizado dos produtos naturais produzidos pela família Dictyotaceae, dando destaque às atividades antioxidante e antifúngica. Esta revisão abre caminhos de discussão sobre a utilização da biodiversidade marinha para desenvolvimento e inovação de novos bioprodutos, promovendo uma abordagem crítica da bioprospecção, sustentabilidade e conservação de algas pardas marinhas

Evaluation of nitrous oxide emission by soybean inoculated with Bradyrhizobium strains commonly used as inoculants in South America

Aims: The purpose of this work was to analyze the agronomic and environmental performance of soybean plants inoculated with the Bradyrhizobium strains widely used as soybean biofertilizers in South America and to determine if these strains possess any functional or taxonomic trait associated with the NO emission. Methods: Bradyrhizobium japonicum E109 and CPAC 15, B. diazoefficiens USDA 110 and CPAC 7, and B. elkanii SEMIA 5019 and SEMIA 587 were used to inoculate soybean seeds. The field experiment was carried out in a soil without history of soybean cultivation in the Argentinian Humid Pampa. The natural N abundance method was applied to estimate N-fixation, and NO production was evaluated using gas chromatography. Among other physiological parameters, shoot dry weight, shoot N content, and crop yield were estimated after harvest. Results: B. japonicum inoculation produced the greatest increases in soybean growth and crop yield but also led to higher NO emissions compared to all other inoculated treatments. Plants inoculated with B. diazoefficiens released the lowest amount of NO, and their growth and yield were the least affected. Inoculation with B. elkanii resulted in intermediate NO emission fluxes and crop yield compared with B. japonicum and B. diazoefficiens. Conclusions: We found that soybean inoculation with strains of B. japonicum and B. elkanii that lack the nosZ gene led to the highest NO emissions under field conditions, but also to the highest crop yield, while inoculation with strains that carry out complete denitrification, nosZ-containing B. diazoefficiens, showed lower NO emission and lower crop yield.To the Instituto de Investigaciones Agrobiotecnológicas (INIAB); Universidad Nacional de Río Cuarto (UNRC); Consejo Nacional de Investigaciones Científcas y Tecnológicas (CONICET), Fondo Nacional de Ciencia y Tecnología (FONCyT); Instituto Nacional de Tecnología Agropecuaria (INTA). FC is Researcher of CONICET at the UNRC. DT and FD are Postdoc and PhD students at the UNRC granted by CONICET. MOC is a former PhD student at the UNRC granted by CONICET. To Mariano Cicchino from INTA Chascomús, who was in charge of sowing and yield estimation at R8. To Juan Pedro Ezquiaga from INTA Castelar, for their contribution to N2O measurements

Asymmetric patterns of recovery in two habitat forming seagrass species following simulated overgrazing by urchins

The persistence of seagrass meadows reflects variation in factors that influence their productivity and consumption. Sea urchins (Amblypneustes pallidus) can over-graze seagrass (Amphibolis antarctica) to create sparse meadows in South Australia, but this effect is not observed in adjacent Posidonia sinuosa meadows despite greater densities of inhabiting urchins. To test the effect of urchin grazing on seagrass biomass, we elevated the density of urchins in meadows of A. antarctica and P. sinuosa and quantified seagrass decline. Urchins removed similar amounts of biomass from both seagrass species, but the loss of leaf meristems was 11-times greater in A. antarctica than in P. sinuosa. In a second experiment to assess the recovery of seagrass, we simulated urchin grazing by clipping seagrass to mimic impacts measured in the first experiment, as well as completely removing all above ground biomass in one treatment. Following simulated grazing, P. sinuosa showed a rapid trajectory toward recovery, while A. antarctica meadows continued to decline relative to control treatments. While both A. antarctica and P. sinuosa were susceptible to heavy grazing loss, consumption of the exposed meristems of A. antarctica appears to reduce its capacity to recover, which may increase its vulnerability to long-term habitat phase-shifts and associated cascading ecosystem changes. © 2013 Elsevier B.V.Owen W. Burnell, Sean D. Connell, Andrew D. Irving, Bayden D. Russel

Propiedades autolimpiantes y antimicrobianas de películas de quitosano funcionalizadas con nanopartículas de urea/TiO2

Las propiedades autolimpiantes de superficies de TiO2 son el resultado de un efecto sinérgico entre la luz UV que induce la generación de especies reactivas de oxígeno (ROS) sobre la superficie, que atacan moléculas orgánicas adsorbidas y la superhidrofilicidad que conduce a la extensión de las gotas de agua. Por otra parte, el TiO2 es un semiconductor con una diferencia de energía (band gap) entre la banda de valencia y la de conducción de 3,2 eV, permitiendo la producción de ROS sólo bajo irradiación UV de longitud de onda inferior a 387 nm. Pocos estudios pueden encontrarse en la literatura sobre la utilización de TiO2 modificado con nitrógeno activado por medio de luz visible como material autolimpiante. Por ejemplo, Irie et al. (2003) y Premkumar (2004) encontraron que películas delgadas de TiO2 dopadas con N2 depositadas sobre SiO2 mostraron super hidrofilicidad bajo luz visible. Ambos autores sugirieron que la actividad a la luz visible sería causada por la disminución del valor del band gap, como fue descrito por Asahi et al. (2001). Por otra parte, polímeros biodegradables pueden usarse como sustratos de nanopartículas de TiO2 para ser evaluados como superficies autolimpiantes. El quitosano (QS) es un poliaminosácarido lineal compuesto por unidades monoméricas, N-acetil glucosamina y Dglucosamina, unidas a través de enlaces glucosídicos β-(1-4) (Lamarra et al. 2017). El QS es un polímero natural con hidrofilicidad, biocompatibilidad, biodegradabilidad y con propiedades no tóxicas que ha sido estudiado como un sustrato para inmovilizar nanopartículas de TiO2. Sin embargo, la mayor parte de parte de los estudios ha sido dirigidos a la absorción de tintes orgánicos de ambientes marítimos, inactivación de bacterias y apósitos cicatrizante de heridas (Archana et al. 2013). En este contexto, los objetivos del trabajo fueron obtener matrices utilizando quitosano como material soporte de nanopartículas de TiO2 estudiando sus propiedades físico-químicas, antimicrobianas y autolimpiantes.Sección: Ingeniería Química.Facultad de Ingenierí