Efficient discrete-event based particle tracking simulation for high energy physics

This work presents novel discrete event-based simulation algorithms based on the Quantized State System (QSS) numerical methods. QSS provides attractive features for particle transportation processes, in particular a very efficient handling of discontinuities in the simulation of continuous systems. We focus on High Energy Physics (HEP) particle tracking applications that typically rely on discrete timebased methods, and study the advantages of adopting a discrete event-based numerical approach that resolves efficiently the crossing of geometry boundaries by a traveling particle. For this purpose we follow two complementary strategies. First, a new co-simulation technique connects the Geant4 simulation toolkit with a standalone QSS solver. Second, a new native QSS numerical stepper is embedded into Geant4. We compare both approaches against the latest Geant4 default steppers in different HEP setups, including a complex realistic scenario (the CMS particle detector at CERN). Our techniques achieve relevant simulation speedups in a wide range of scenarios, particularly when the intensity of discrete-event handling dominates performance in the solving of the continuous laws of particle motion.Fil: Santi, Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Rossi, Lucas Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Castro, Rodrigo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; Argentin

Mapeo por asociación de resistencia a la enfermedad Mal de Río Cuarto en maíz

El Mal de Río Cuarto (MRC) es la enfermedad viral más importante del maíz (Zea mays L.) en Argentina. El uso de genotipos resistentes es el medio más económico, ambientalmente sostenible y efectivo para controlar enfermedades en cultivos extensivos. El objetivo de este trabajo fue identificar regiones genómicas asociadas con la resistencia a la enfermedad MRC en un grupo de líneas de maíz de CIMMYT. Una revisión sistemática y un meta-análisis se realizaron con el propósito de identificar cromosomas que portan QTL de efecto mayor para resistencia a enfermedades virales en maíz. La evaluación fenotípica de 291 líneas de maíz se realizó en cuatro localidades de la provincia de Córdoba, Argentina durante 2015/16, 2016/17 y 2017/18. La combinación año-localidad definió nueve ambientes. A partir de los síntomas observados se estimaron los caracteres severidad (SEV), incidencia (INC) e índice de severidad de la enfermedad (ISE) MRC. Las medias ajustadas de las líneas de maíz en cada uno de tres ambientes y la mejor predicción lineal insesgada (BLUP) a través de éstos se estimaron mediante modelos lineales mixtos. A partir de la caracterización genotípica disponible públicamente de las líneas de maíz, se seleccionaron 45.925 SNPs. El análisis de estructura genética poblacional indicó la presencia de tres subgrupos definidos en base a la adaptación ambiental de las líneas de maíz. El análisis del desequilibrio de ligamiento (DL) mostró una rápida caída (10-20 kb; r2<0,10) que brindó la posibilidad de alcanzar una alta resolución de mapeo. El análisis de mapeo por asociación se realizó para los tres ambientes que permitieron diferenciar a los genotipos. Este permitió identificar 54 marcadores SNPs, en 46 regiones genómicas, asociados significativamente con la resistencia a la enfermedad MRC. La variación fenotípica explicada por estos QTL osciló entre 6% y 24%, con un valor medio de 10%. Veintitrés de estos marcadores se encuentran en regiones donde previamente se reportaron grupos de genes y QTL para resistencia a enfermedades virales en maíz. El análisis de regresión lineal múltiple con los marcadores significativos en la asociación permitió identificar 2, 3, 4 y 5 SNPs que explicaron entre 21% y 44% de la variación fenotípica, según carácter y ambiente. Estos SNPs resultan promisorios para la selección de líneas de maíz de CIMMYT con alelos favorables para la resistencia a la enfermedad MRC.Mal de Rio Cuarto(MRC) is the most important viral disease of maize (Zea maysL.) in Argentina. The development of resistant genotypes is the most economical, environmentally sustainable and effective wayfor controlling this disease. The aim of this study was to detect genomic regions associated with resistance to MRC disease in maize lines. Systematic review and meta-analysis were performed to identify chromosomes carrying major-effect QTL for resistance to viral diseases in maize. Severity (SEV), incidence (INC) and disease severity index (DSI) estimated in three environments and 45,925 SNPsin a population of genotypes were used to identify genomic regions associated with MRC disease resistance. Mixed models were used to estimate the best linear unbiased estimation(BLUE) of maize linesin each environment and the best linear unbiased prediction (BLUP) across environment. Population structure analysis showed three subgroups. Linkage disequilibrium(LD) analysis indicated faster LD decay(10-20 kb; r2<0,10),that allowed achievement a higher mapping resolution. Association mapping allowed to identify 54 significant SNPs associated to MRC resistancein all environments. These SNPs were grouped in 46 genomic regions.The phenotypic variation explained by these QTL ranged between 6% and 24%,with an average value of 10%. Twenty-three SNPs were localized in the same genomic regions where previously were reported maize viral diseases resistance QTLs and gene clusters. The ability of multiple linear regression models toexplain large proportions of the phenotypic variances suggests that simple assays involving a small number of SNP scould be designed for selecting lines with favorable alleles for MRC disease resistance.Fil: Rossi, Ezequiel Alejandro. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Preparation of an environmentally friendly lead adsorbent. A contribution to the rational design of heavy metal adsorbents

This work described the preparation and characterization of water insoluble chitosan derivatives as lead adsorbents. In highly regioselective reactions, N-substituted crosslinked chitosan derivatives were obtained by crosslinking native chitosan with mucic and adipic acid (a polyhydroxylated and a non-functionalized diacid of the same length chains). The crosslinking degree of the chitosan modified with adipic acid was significantly higher than that crosslinked with mucic acid (0.446 and 0.316, respectively), while the degree of substitution was almost the same (approximately 80 %). Lead adsorption isotherms were constructed at different temperatures and adjusted to well-known models, obtaining the best fit to the experimental data with Langmuir model. The lead adsorption capacity of new materials was greater than many of the adsorbents described in literature (76.3 and 69.7 mg g−1 for chitosan modified with mucic and adipic acid, respectively). Moreover, thermodynamic parameters were calculated, and results showed that the lead adsorption on the derivatives was spontaneous, exothermic, and governed by chemical interaction. Besides, kinetic studies were performed and adjusted to well-known models. The pseudo-second order kinetic equation was the one that most appropriately described the lead adsorption on the new materials. Results were consistent with the strong electrostatic attraction established between the lead cations and the free carboxylate groups of the derivatives.Fil: Rossi, Ezequiel. Instituto Tecnológico de Buenos Aires. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Avila Ramirez, Jhon Alejandro. Instituto Tecnológico de Buenos Aires. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Errea, María Inés. Instituto Tecnológico de Buenos Aires. Departamento de Ingeniería Química; Argentin

Avaliação de diferentes fontes de adubos organominerais na nutrição da urochloa brizantha cv. Marandu

Brazilian livestok every year is becoming more technological, increasing competitiveness in the sector, thus requiring cattle breeder to search for expertise to improve the production of their herds. Consequently, fertilization plays a very important role in livestock production in order to obtain a satisfactory forage production. Mineral fertilization is a widely used tool that has the function of adding all the nutrients that the forages need, but does not always contribute to the preservation of the environment, thus giving rise to an option that besides maintaining production, has a good chance of increasing the production of forage, which is the use of organomineral fertilizers. They are organic fertilizers mixed with mineral nutrients, which can bring benefits to the soil structure, improving the biological, physical and chemical quality of the soil, in addition to bringing environmental benefits. This study was aimedat evaluate the influence of organomineral fertilization on nutrition Urochloa brizantha cv. Marandu. The experiment was implemented in a randomized complete block design, where seven treatments with three replications were used in the factorial scheme of 2 x 3 +1, where two sources of organomineral fertilizers were used in three different doses with an additional mineral fertilizer , with a total of 28 plots. The doses of the organomineral fertilizers were established from the recommended dose of mineral fertilization, varying only the percentage of fertilization, taking the doses of 50%, 100% and 150%, varying only the sources of the fertilizers that are, filter cake and sewage sludge. It was concluded that the organomineral fertilization was not superior to mineral fertilization in most of the evaluated phytotechnical variables, being an option that will not decrease the production and will bring profits in the same way contributing to the environment.Trabalho de Conclusão de Curso (Especialização)A pecuária brasileira a cada ano está se tecnificando, aumentando à competitividade no mercado, exigindo assim dos pecuaristas a busca por conhecimento para melhorar a produção de seus rebanhos. Desse modo, a adubação tem um papel muito importante na pecuária para se obter uma produção de forragem satisfatória. A adubação mineral é uma ferramenta muito utilizada que tem como função adicionar todos os nutrientes que as forrageiras necessitam, porém nem sempre contribui com a preservação do ambiente, surgindo então uma opção que além de manter a produção, possui boas chances de aumentar a produção de forragem, opção essa que é a utilização de adubos organominerais. Eles são adubos orgânicos misturados com nutrientes minerais, que podem trazer benefícios na estrutura do solo, melhorando a qualidade biológica, física e química do solo, além de trazer benefícios ambientais. Então o objetivo desse trabalho foi avaliar influência da adubação organomineral na nutrição Urochloa brizantha cv. Marandu. O experimento foi implantado no sistema de delineamento estatístico de blocos casualizados, onde era constituído de sete tratamentos com três repetições no esquema fatorial de 2 x 3 +1, onde se utilizou duas fontes de adubos organominerias em três diferentes doses com um adicional de adubo mineral, tendo um total de 28 parcelas. As doses dos adubos organominerais foram estabelecidos a partir da dose recomendada da adubação mineral, variando apenas a porcentagem de adubação, tendo nos as doses de 50%, 100% e 150%, variando apenas as fontes dos adubos que são, torta de filtro e lodo de esgoto. Conclui-se que a adubação organomineral não foi superior a adubação mineral na maioria da variáveis fitotécnicas avaliadas, sendo uma opção que não irá diminuir a produção e trará lucros da mesma forma contribuindo então com o meio ambiente

Which policies for which audiovisual development: The national regulatory possibility of global video-on-demand platforms

Las plataformas globales de video a demanda se han convertido -por el volumen de capital que movilizan, sus formas de funcionamiento desterritorializado y el impacto creciente sobre la producción y distribución de contenidos-, en actores centrales dentro del complejo audiovisual argentino. Sus políticas de licenciamiento, producción y promoción de contenidos originales las pone en relación con proveedores de contenidos o prestadores de servicios audiovisuales, con quienes mantienen vínculos caracterizados por una profunda asimetría e interdependencia. Asimismo, el Estado Nacional tiene un acotado margen de maniobra para disponer regulaciones, definir y encuadrar legalmente esta actividad, más allá de su inclusión como actividades alcanzadas por el Impuesto al Valor Agregado. El objetivo del artículo es aportar a la caracterización de los marcos implícitos de desarrollo en las viabilidades regulatorias proyectadas entre el Estado nacional, los actores locales de la producción audiovisual tradicional y las plataformas globales. Para esto, la estrategia teórico-metodológica consiste en la revisión crítica de una serie de postulados de la teoría del desarrollo y la dependencia que, entendemos, aportan a una profundización del análisis de los movimientos de estos actores y sus juegos políticos. Entre las conclusiones del artículo destacamos la necesidad de clarificar estos posicionamientos que enmarcan los relatos sobre una actualización regulatoria para estos servicios convergentes, y sobre las formas en que el Estado debe intervenir para garantizar diversidad en la producción, distribución, temáticas y consumo de bienes y servicios audiovisuales.Due to the volume of capital they mobilize, their deterritorialized forms of operation and the growing impact on the production and distribution of content, global video-ondemand platforms have become central players within the Argentine audiovisual complex. Their policies for licensing, production and promotion of original content put them in relationship with content providers or providers of audiovisual services, with whom they maintain business relationships characterized by profound asymmetry and interdependence. Likewise, the National State has a limited margin of maneuver to establish regulations, define and legally frame this activity, beyond its inclusion as activities covered by the Value Added Tax. The objective of the article is to contribute to the characterization of the implicit frameworks of development in the projected regulatory viability between the national State, the local actors of traditional audiovisual production and global platforms. To this end, the theoretical-methodological strategy consists of a critical review of a series of postulates from the development and dependency theories that, as we understand, contributes to a deeper analysis of the movements of these actors and their political games. Among the conclusions of the article, we highlight the need to clarify these positions that frame the narratives about a regulatory update for these converging services, and about the ways in which the State must intervene to guarantee diversity in the production, distribution, themes, and consumption of audiovisual goods and services.Fil: Rivero, Ezequiel Alexander. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencias Sociales; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Rossi, Diego. Universidad de Buenos Aires; Argentin

Identifying inbred lines with resistance to endemic diseases in exotic maize germplasm

Mal de Rio Cuarto (MRC) and common rust (CR), caused by Mal de Rio Cuarto virus (MRCV) and Puccinia sorghi, respectively, are endemic diseases affecting maize (Zea mays L.) production in Argentina. Exotic maize germplasm is an important source of resistance to these diseases. The aim of this work was to identify maize lines that exhibit MRC and CR resistance. A multienvironment trial was performed to phenotypically assess a diverse panel of inbred lines from the International Maize and Wheat Improvement Center (CIMMYT). The maize lines were evaluated using a disease severity index (DSI) for MRC and CR in the central area of Argentina. A multitrait mixed linear model (MLM) was used to identify the lines with the best performance for both diseases and estimate genetic parameters. No correlation of resistance between MRC and CR was found among the tested lines. Additionally, best linear unbiased predictions (BLUPs) of genotypic effects were used as response variable to perform a genome-wide association study (GWAS). The GWAS revealed promising alleles for maize breeding, two associated with MRC and three with CR. Lines with lower DSI for MRC and CR were identified as novel materials for incorporating resistance to the local germplasm.Fil: Rossi, Ezequiel Alejandro. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Ruiz, Marcos. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Bonamico, Natalia Cecilia. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Balzarini, Monica Graciela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentin

Which policies for which audiovisual development: The national regulatory possibility of global video-on-demand platforms

Las plataformas globales de video a demanda se han convertido -por el volumen de capital que movilizan, sus formas de funcionamiento desterritorializado y el impacto creciente sobre la producción y distribución de contenidos-, en actores centrales dentro del complejo audiovisual argentino. Sus políticas de licenciamiento, producción y promoción de contenidos originales las pone en relación con proveedores de contenidos o prestadores de servicios audiovisuales, con quienes mantienen vínculos caracterizados por una profunda asimetría e interdependencia. Asimismo, el Estado Nacional tiene un acotado margen de maniobra para disponer regulaciones, definir y encuadrar legalmente esta actividad, más allá de su inclusión como actividades alcanzadas por el Impuesto al Valor Agregado. El objetivo del artículo es aportar a la caracterización de los marcos implícitos de desarrollo en las viabilidades regulatorias proyectadas entre el Estado nacional, los actores locales de la producción audiovisual tradicional y las plataformas globales. Para esto, la estrategia teórico-metodológica consiste en la revisión crítica de una serie de postulados de la teoría del desarrollo y la dependencia que, entendemos, aportan a una profundización del análisis de los movimientos de estos actores y sus juegos políticos. Entre las conclusiones del artículo destacamos la necesidad de clarificar estos posicionamientos que enmarcan los relatos sobre una actualización regulatoria para estos servicios convergentes, y sobre las formas en que el Estado debe intervenir para garantizar diversidad en la producción, distribución, temáticas y consumo de bienes y servicios audiovisuales.Due to the volume of capital they mobilize, their deterritorialized forms of operation and the growing impact on the production and distribution of content, global video-ondemand platforms have become central players within the Argentine audiovisual complex. Their policies for licensing, production and promotion of original content put them in relationship with content providers or providers of audiovisual services, with whom they maintain business relationships characterized by profound asymmetry and interdependence. Likewise, the National State has a limited margin of maneuver to establish regulations, define and legally frame this activity, beyond its inclusion as activities covered by the Value Added Tax. The objective of the article is to contribute to the characterization of the implicit frameworks of development in the projected regulatory viability between the national State, the local actors of traditional audiovisual production and global platforms. To this end, the theoretical-methodological strategy consists of a critical review of a series of postulates from the development and dependency theories that, as we understand, contributes to a deeper analysis of the movements of these actors and their political games. Among the conclusions of the article, we highlight the need to clarify these positions that frame the narratives about a regulatory update for these converging services, and about the ways in which the State must intervene to guarantee diversity in the production, distribution, themes, and consumption of audiovisual goods and services.Fil: Rivero, Ezequiel Alexander. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencias Sociales; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Rossi, Diego. Universidad de Buenos Aires; Argentin

Genome-wide association study of resistance to Mal de Río Cuarto disease in maize

Argentine maize has been extensively screened for incidence (INC) and severity (SEV) of Mal de Río Cuarto disease (MRC), caused by Mal de Río Cuarto virus (MRCV), family Reoviridae, genus Fijivirus, narrowing the breeding genetic basis. Both traits are highly heritable phenotypic measurements, and quantify the strong disease impact on grain yield. The adaptation of exotic germplasm to variation of those traits has not been explored. The aim of this work was to identify, in a non-local and diverse panel of maize inbred lines, novel genomic regions associated with resistance to MRC. First, we phenotyped 206 maize inbred lines from the International Maize and Wheat Improvement Center (CIMMYT), in several environments of the MRC-endemic area under natural virus infection, to obtain the best linear unbiased predictor (BLUP) of line effects regarding INC and SEV. A multi-environment and multi-trait mixed linear model was fitted to derive the multivariate BLUPs. Genetic variance and mean-basis heritability were high in both traits and a significant genetic correlation among them was found. Second, we performed a genome-wide association study (GWAS) by linking the BLUPs with 78,376 SNP markers available for 186 lines. The GWAS identified new alleles for resistance to MRC in six genomic regions from the exotic germoplasm. Four of them reduce symultaneously the appearance and severity of disease symptoms. Improved susceptible parental lines through marker-assisted recurrent selection would allow us to increase the resistance of maize hybrids to MRC disease.Fil: Rossi, Ezequiel Alejandro. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Ruiz, Marcos. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Bonamico, Natalia Cecilia. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Balzarini, Monica Graciela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentin

HERC1 regulates breast cancer cells migration and invasion

Tumor cell migration and invasion into adjacent tissues is one of the hallmarks of cancer and the first step towards secondary tumors formation, which represents the leading cause of cancer-related deaths. This process is considered an unmet clinical need in the treatment of this disease, particularly in breast cancers characterized by high aggressiveness and metastatic potential. To identify and characterize genes with novel functions as regulators of tumor cell migration and invasion, we performed a genetic loss-of-function screen using a shRNA library directed against the Ubiquitin Proteasome System (UPS) in a highly invasive breast cancer derived cell line. Among the candidates, we validated HERC1 as a gene regulating cell migration and invasion. Furthermore, using animal models, our results indicate that HERC1 silencing affects primary tumor growth and lung colonization. Finally, we conducted an in silico analysis using publicly available protein expression data and observed an inverse correlation between HERC1 expression levels and breast cancer patients’ overall survival. Altogether, our findings demonstrate that HERC1 might represent a novel therapeutic target for the development or improvement of breast cancer treatment.Fil: Rossi, Fabiana Alejandra. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; ArgentinaFil: Calvo Roitberg, Ezequiel Hernán. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; ArgentinaFil: Enriqué Steinberg, Juliana Haydeé. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; ArgentinaFil: Joshi, Molishree Umesh. University of Colorado; Estados UnidosFil: Espinosa, Joaquín Maximiliano. University of Colorado; Estados UnidosFil: Rossi, Mario. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; Argentin

Carboxymethylated bacterial cellulose: An environmentally friendly adsorbent for lead removal from water

Carboxymethylated bacterial cellulose (CMBC) was synthesized under controlled reaction condition to provide a material with a degree of substitution (DS) that guarantees that the characteristic water insolubility of cellulose is retained (DS = 0.17). The CMBC synthesized was fully characterized by conductometric titration, infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis and solubility assays. The suitability of the produced CMBC for lead removal from water was evaluated. Experimental isotherm data were fitted to different models of sorption isotherms: Langmuir, Freundlich, Dubinin-Radushkevich, and Frumkin, with Langmuir equation resulting in the best fit. Kinetic data were also adjusted to pseudo-first-order and pseudo-second-order models and results undoubtedly showed that the pseudo-second-order kinetic equation was the one that most appropriately described the lead adsorption of CMBC, indicating that lead is adsorbed on CMBC predominantly by chemical interaction. The breakthrough curve was fitted to different models: Bohart-Adams, Clark and Modified Dose-Response, being the Bohart-Adams equation the one that gave the best fit. Desorption studies were carried out in order to know the technical feasibility of the reuse of CMBC. Almost 96% of the retained lead was eluted in just 20 mL, and the CMBC lifetime was over 50 adsorption/desorption cycles. Overall, results obtained suggest that the CMBC herein synthesized may result in an alternative economic and environmentally friendly lead adsorbent for water treatment.Fil: Rossi, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Montoya Rojo, Ursula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Cerrutti, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química; ArgentinaFil: Foresti, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Errea, María Inés. Instituto Tecnológico de Buenos Aires; Argentin