1,720,978 research outputs found
Recognition-driven assembly of self-limiting supramolecular protein nanoparticles displaying enzymatic activity
Full text linkWe report the recognition-driven assembly of self-limiting protein nanoparticles displaying enzymatic activity. Solution self-assembly of concanavalin A lectin and glycoenzyme glucose oxidase leads to the spontaneous formation of biocolloids with well-defined dimensions, narrow size distribution and remarkable stability. These biocolloids successfully recognize a glycosylated modified electrode retaining the enzyme activity.Fil: Piccinini, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Pallarola, Diego Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Battaglini, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
Auto-ensamblados supramoleculares de nanomateriales blandos para aplicaciones de biosensado: control de la nanoarquitectura y sus propiedades funcionales
Full text linkEsta tesis doctoral se enfoca en el diseño racional de auto-ensamblados supramoleculares de macromoléculas y biomacromoléculas para la construcción de películas delgadas con propiedades funcionales. Uno de los aspectos de gran interés en esta tesis comprende el estudio de la influencia que tienen las características estructurales de los ensamblados en sus propiedades funcionales para dos clases de plataformas transductoras: í) transductores amperométricos, donde la respuesta electrónica se basa en procesos faradaicos entre el electrodo y la interfase. ii) transistores de efecto de campo a base de grafeno donde la respuesta del sensor se basa en detección de cambios fisicoquímicos no-faradicos como cambios de pH y fuerza iónica. A lo largo de este trabajo se utiliza la técnica de ensamblado capa-por-capa (conocida con la abreviatura LbL del inglés Layer-by-Layer) como principal técnica de nanoconstrucción siendo que permite un control preciso de los bloques de construcción, y por ser efectiva, versátil, simple y de bajo costo. Se exploran la incorporación de distintas moléculas a las arquitecturas interfaciales: surfactantes, polielectrolitos y proteínas (lectinas y enzimas). Primero se estudian los ensamblados multicapa (hexadeciltrimetilamonio/ácido poliacrílico)n y se observa que el surfactante funciona como agente mesogénico aumentando el grado de organización interna de las películas. Luego, se estudia la incorporación de surfactantes redox para la construcción de películas (hexadecil(ferrocenilmetil)dimetilamonio/ácido poliacrílico)n con arquitectura organizada y electroactiva. Por el alto nivel de organización, estos sistemas muestran propiedades electroactivas inusuales. Se estudia también la construcción de suprapartículas auto-ensambladas y auto-limitadas en tamaño formada a partir de la lectina concanavalina A y la glicoenzima redox glucosa oxidasa. Estos biocoloides son inmovilizados sobre superficies de electrodos para la construcción de películas que biocatalizan la oxidación de glucosa, propiedad que es utilizada para el desarrollo de sensores amperométricos de glucosa. Por último, se estudia la construcción de ensamblados multicapa (policatión/polianion)n y (policatión/ureasa)n sobre transistores de efecto de campo a base de grafeno. Los resultados indican que los ensamblados de polielectrolitos aumentan el rango de sensibilidad interfacial de los transistores y que la integración de la enzima ureasa resulta en interfases que catalizan la hidrólisis de urea. Estos sistemas muestran características sonbresalientes para ser utilizados como sensores para el monitoreo de urea sin la necesidad del uso de soluciones reactivas.This doctoral thesis is focused on the rational design of supramolecular self-assemblies of macromolecules and biomacromolecules for the construction of thin films displaying functional properties. One of the main points of interest in this thesis comprises the study of the influence of the structural features within the assemblies on its functional properties for two different transducing platforms: i) amperometric platforms, whose electronic response is based on faradaic process between the electrode and the interface; ii) graphene based field-effect transistors, whose response is based on the detection of physicochemical non-faradaic changes such as pH and ionic strength changes. Through this work, the Layer-by-Layer (LbL) approach is used as the main nanoconstruction technique, given its properties as effective, versatile, simple and low cost. The incorporation of different molecules such as surfactants, polyelectrolytes and proteins (lectins and enzymes) into the interfacial architectures is explored. Firstly, the study of multilayer assemblies of (hexadecyltrimethylammonium/polyacrylic acid)n shows that the surfactant acts as a mesogenic agent leading to films with high degree of internal organization. Subsequently, the incorporation of a redox surfactant for the construction of (hexadecyl(ferrocenylmethyl)dimethylammonium/polyacrylic acid)n assemblies was studied. This highly organized and electroactive architecture shows unusual redox properties. The formation of self-assembled and self-limited supraparticles from concanavalin A, a model lectin, and glucose oxidase, a model redox glycoenzyme, was also studied. These colloidal systems are immobilized on electrode surfaces for the construction of thin films, which are able to catalyze the glucose oxidation, a property used for the development of glucose amperometric sensors. Lastly, the construction of (polycation/polyanion)n and (polycatión/urease)n assemblies on graphene-based field-effect transistors is studied. The results indicate that the polyelectrolyte assemblies increase the range of interfacial sensitivity of the transistors and that the integration of the urease leads to intarfaces that catalyze the urea hydrolysis. These systems show outstanding characteristics to be used as urea label-free sensors.Fil: Piccinini, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Self-limited self-assembly of nanoparticles into supraparticles: towards supramolecular colloidal materials by design
Full text linkFor quite a while, scientists have resorted to colloidal synthesis to mimic complex structural and functional materials found in Nature. In particular, within the past few years, the synthesis of suprastructures with novel properties that emerge from the coupling of diverse nanoscale functional units has defined new boundaries in materials science. In this mini-review, we survey the most recent and outstanding achievements on the rational design of supraparticles based on the self-limited self-assembly of nanoparticles, and their application in fields like biology, medicine and energy.Fil: Piccinini, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Pallarola, Diego Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Battaglini, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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