Síntesis y caracterización de nanopartículas de oro

Gold nanoparticles (AuNPs) find a number of applications in many fields of electronics, catalysis, optics and biomedicine. This work reports a robust, fast and easy synthesis protocol, based on the Turkevich method to obtain AuNPs.Simple characterization techniques based on UV-Vis spectroscopy and transmission electronic microscopy are also reported. The resulting AuNPs presents properties at a nanometric scale, high purity and they may find potential uses in the treatment of cancer, antiviral and antibacterial agents and biosensors among othersLas nanopartículas de oro tienen múltiples aplicaciones en electrónica, catálisis, óptica y biomedicina. Este trabajo informa acerca de un protocolo robusto, rápido y fácil para síntesis de AuNPs. El protocolo de síntesis es una variante del método de Turkevich para la obtención de AuNPs. También se informa acerca de la caracterización del producto de síntesis mediante espectroscopia UV-Vis y microscopía electrónica de transmisión. Las AuNPs obtenidas presentaron propiedades de nanoescala, alta pureza y tienen usos potenciales en el tratamiento de cánceres, como agentes antivirales, antibacteriales y biosensores, entre otros.Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Development a Process of Technological Innovation for Industrial Paper Production

Thispaper presents a description of an innovative process applied to theproduction of paper from the use of stem fibers of the banana plant.According to the Organization for Economic Co-operation andDevelopment Oslo Guidelines, innovation is essential for growth inproduction as well as productivity and is a continuous process thatmakes changes in products, processes and captures new knowledge. Inorder to guarantee product (paper) and process (pulp system)innovation, a comparison was made with the mechanical properties ofpaper obtained from the organic waste with a typed paper commercialuse wave produced in a paper industry located in Asunción-Paraguay.The temperature, time and reagents chemical were operationalvariables selected to comparison of innovative processes. The yieldof innovator process analyzed was 52.5%. The results of comparison ofprocesses for obtaining cellulosic pulp indicates that mechanicalproperties as Stress (N.m/g), Compression in the plane (N) andresistance to compression in the edge (N) increase in comparison withconventional processes (Chemical process to soda and ChemicalProcess Kraft ) and this properties are highly valued by the paperindustries for use in corrugating industries. The (pulp system)innovation process presents many technical and economic advantagesamong alternative processes for paper production.Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Quiroga, Oscar. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Ingeniería Industrial; ArgentinaFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Multifactorial effects of gelling conditions on mechanical properties of skin-like gelatin membranes intended for in vitro experimentation and artificial skin models

The development of new cosmetic products, skin contact medical devices, skin medicaments, wound care devices, tattooing and piercing has experienced an impressive growth in recent years. In parallel, new restrictions to in vivo experimentation in animals and humans have been widely implemented by regulatory authorities. New knowledge about alternative materials for in vitro skin-related experimentation is required to overcome these severe limitations. This paper presents a set of three 4-D surface response equations describing the mechanical properties of skin-like gelatin membranes intended for use as an alternative biomaterial for in vitro skin-related experimentation. The membranes were obtained by a sol-gel method. The novelty of this contribution is the establishment of the cross-dependency effects of key synthesis conditions on the final mechanical properties of gelatin membranes. The results of this work are useful to produce gelatin membranes with tailored mechanical properties mimicking different types of human skins. In particular, membranes with Young’s modulus of 1 MPa and maximum tensile strength of 0.85 MPa were obtained.Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Daza Agudelo, Jorge Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Effect of Processing on the Nutritional Quality of Ilex paraguariensis

Ilex paraguariensis A.St.-Hil. (IP) is a South American plant. IP-dried leaves have been consumed in the form of infusion by indigenous peoples since pre-Hispanic times. In recent years, IP has gained many beverage markets and new ways of consumption, reaching the category of a global consumer product. A side consequence is the increase in IP crops for the specification of human consumption. This situation is the driving force for the investigation of new uses of IP, including feed supplements for livestock and functional food for human consumption. A deep understanding of the influence of processing on the nutritional value of IP is crucial for the development of these alternative products. It is known that the quality and quantity of nutritional compounds occurring in IP depend on the origin, plant condition, and harvest time. However, the effects of the drying method of the leaves and the ageing time of dried leaves on the final IP products deserve further investigation. The present work presents the variation of the nutritional, digestibility, energy, and mineral assets of IP submitted to three different processes: open-air dried and crushed; dried under direct fire and grounded; and dried under direct fire, grounded, and aged for 6 months under controlled conditions. The presence of agrochemical residues and antinutritional factors were also studied. Processing widely influenced the nutritional and digestibility assets of IP leaves. The inorganic content (K, Mg, Ca, P, Zn, B and Fe) significantly varied among leaves treated using different processes. IP samples dried in open air resulted in the highest % of crude protein, Mg, K, S, and Mn. IP samples dried under direct fire resulted in the highest % of carbohydrates and Fe. IP samples dried under direct fire and aged for 6 months resulted in the highest % of digestible matter, Ca, P, Zn, and B. The results also showed quality protein levels between 10.03 and 19.06% of dry matter. The digestibility values showed that IP leaves are suitable for human functional foods and for enriched supplements for livestock feeds. No traces of agrochemicals or antinutritional factors were found.Fil: Ramirez, Maria Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mohamad, Leandro. No especifíca;Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Catalytic effects of magnetic and conductive nanoparticles on immobilized glucose oxidase in skin sensors

Wearable skin sensors is a promising technology for real-time health care monitoring. They are of particular interest for monitoring glucose in diabetic patients. The concentration of glucose in sweat can be more than two orders of magnitude lower than in blood. In consequence, the scientific and technological efforts are focused in developing new concepts to enhance the sensitivity, decrease the limit of detection (LOD) and reduce the response time (RT) of glucose skin sensors. This work explores the effect of adsorbed superparamagnetic magnetite nanoparticles (MNPs) and conductive nanoparticles (CNPs) on carbon nanotube substrates (CNTs) used to immobilize glucose oxidase enzyme in the working electrode of skin sensors. MNPs and CNPs are made of magnetite and gold, respectively. The performance of the sensors was tested in standard buffer solution, artificial sweat, fresh sweat and on the skin of a healthy volunteer during an exercise session. In the case of artificial sweat, the presence of MNPs accelerated the RT from 7 to 5 s at the expense of increasing the LOD from 0.017 to 0.022 mM with slight increase of the sensitivity from 4.90 to 5.09 μAm M-1 cm-2. The presence of CNPs greatly accelerated the RT from 7 to 2 s and lowered the LOD from 0.017 to 0.014 mM at the expense of a great diminution of the sensitivity from 4.90 to 4.09 μAm M-1 cm-2. These effects were explained mechanistically by analyzing the changes in the concentration of free oxygen and electrons promoted by MNPs and CNPs in the CNTs and its consequences on the the glucose oxidation process.Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Bandodkar, Amay J.. Northwestern University; Estados UnidosFil: Rogers, John A.. Northwestern University; Estados UnidosFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Biocompatible polymers for skin-integrated bioelectronics: A Mini-Review

Many diseasesmanifest themselves through physiological changes in the skin. Themonitoring of disease-associated metabolites in the skin usingbiosensors is a rapidly growing technology that allows the controland diagnosis of diseases almost in real time and with great comfortfor the users. There are currently two major technological trends.Biosensors integrated (tattoo sensors) in the dermis and biosensorsattached to the epidermis (wearable sensors). The contact surfacebetween the biosensors and these skin tissues and fluids is criticalto ensure biocompatibility, sensitivity to the target metabolite,comfort for the user, security and several other features. Ingeneral, the surfaces of the biosensors are made of functionalbiopolymers. This article summarizes the characteristics of thebiopolymers currently used in the construction of skin biosensorsintended for glucose monitoring in sweat.p { margin-bottom: 0.25cm; line-height: 120% }Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rintoul, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Effect of Processing on the Nutritional Quality of Ilex paraguariensis

Ilex paraguariensisA.St.-Hil. (IP) is a South American plant. IP-dried leaves have been consumed in the form of infusion by indigenous peoples since pre-Hispanic times. In recent years, IP has gained many beverage markets and new ways of consumption, reaching the category of a global consumer product. A side consequence is the increase in IP crops for the specification of human consumption. This situation is the driving force for the investigation of new uses of IP, including feed supplements for livestock and functional food for human consumption. A deep understanding of the influence of processing on the nutritional value of IP is crucial for the development of these alternative products. It is known that the quality and quantity of nutritional compounds occurring in IP depend on the origin, plant condition, and harvest time. However, the effects of the drying method of the leaves and the ageing time of dried leaves on the final IP products deserve further investigation. The present work presents the variation of the nutritional, digestibility, energy, and mineral assets of IP submitted to three different processes: open-air dried and crushed; dried under direct fire and grounded; and dried under direct fire, grounded, and aged for 6 months under controlled conditions. The presence of agrochemical residues and antinutritional factors were also studied. Processing widely influenced the nutritional and digestibility assets of IP leaves. The inorganic content (K, Mg, Ca, P, Zn, B and Fe) significantly varied among leaves treated using different processes. IP samples dried in open air resulted in the highest % of crude protein, Mg, K, S, and Mn. IP samples dried under direct fire resulted in the highest % of carbohydrates and Fe. IP samples dried under direct fire and aged for 6 months resulted in the highest % of digestible matter, Ca, P, Zn, and B. The results also showed quality protein levels between 10.03 and 19.06% of dry matter. The digestibility values showed that IP leaves are suitable for human functional foods and for enriched supplements for livestock feeds. No traces of agrochemicals or antinutritional factors were found

A multiparametric model for the industrialization of co-precipitation synthesis of nano-commodities

Magnetite superparamagnetic nanoparticles (MNP) are becoming one of the firsts nanocommodity products. MNP find a number of applications and they are been produced at relatively large scale. The co-precipitation method presents many technical and economical advantages among alternative processes. However, the relationships between physical and chemical reaction conditions during the co-precipitation process and the resulting properties of obtained MNP are not yet fully understood. The novelty of this contribution is the establishment of the cross-dependency effects of the main physical and chemical parameters of the coprecipitation reaction on the properties of resulting MNP. The conditions were varied by following an experimental design. The crystallite size, particle size and magnetization of the MNP and the Z-potential and size of their aggregates were selected as main response properties. A set of equations in the form of 4D surface responses in the space of co-precipitation process variables was obtained and analyzed in terms of the resulting properties. The set of equations is useful to predict, optimize and tailor very precisely the properties of resulting MNP as a function of reaction conditions.Fil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Daza Agudelo, Jorge Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Glisoni, Romina Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Acha, Carlos Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: de Zan, María Mercedes. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Rintoul, Ignacio. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Wireless, Battery-Free Implants for Electrochemical Catecholamine Sensing and Optogenetic Stimulation

Neurotransmitters and neuromodulators mediate communication between neurons and other cell types; knowledge of release dynamics is critical to understanding their physiological role in normal and pathological brain function. Investigation into transient neurotransmitter dynamics has largely been hindered due to electrical and material requirements for electrochemical stimulation and recording. Current systems require complex electronics for biasing and amplification and rely on materials that offer limited sensor selectivity and sensitivity. These restrictions result in bulky, tethered, or battery-powered systems impacting behavior and that require constant care of subjects. To overcome these challenges, we demonstrate a fully implantable, wireless, and battery-free platform that enables optogenetic stimulation and electrochemical recording of catecholamine dynamics in real time. The device is nearly 1/10th the size of previously reported examples and includes a probe that relies on a multilayer electrode architecture featuring a microscale light emitting diode (μ-LED) and a carbon nanotube (CNT)-based sensor with sensitivities among the highest recorded in the literature (1264.1 nA μM-1 cm-2). High sensitivity of the probe combined with a center tapped antenna design enables the realization of miniaturized, low power circuits suitable for subdermal implantation even in small animal models such as mice. A series of in vitro and in vivo experiments highlight the sensitivity and selectivity of the platform and demonstrate its capabilities in freely moving, untethered subjects. Specifically, a demonstration of changes in dopamine concentration after optogenetic stimulation of the nucleus accumbens and real-time readout of dopamine levels after opioid and naloxone exposure in freely behaving subjects highlight the experimental paradigms enabled by the platform.Fil: Stuart, Tucker. University of Arizona; Estados UnidosFil: Jeang, William J.. Northwestern University; Estados UnidosFil: Slivicki, Richard A.. University of Washington; Estados UnidosFil: Brown, Bobbie J.. University of Washington; Estados UnidosFil: Burton, Alex. University of Arizona; Estados UnidosFil: Brings, Victoria E.. University of Washington; Estados UnidosFil: Agyare, Prophecy. Northwestern University; Estados UnidosFil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Ruiz, Savanna. Northwestern University; Estados UnidosFil: Tyree, Amanda. University of Arizona; Estados UnidosFil: Pruitt, Lindsay. University of Arizona; Estados UnidosFil: Madhvapathy, Surabhi. Northwestern University; Estados UnidosFil: Niemiec, Martin. University of Arizona; Estados UnidosFil: Zhuang, James. University of Arizona; Estados UnidosFil: Krishnan, Siddharth. Northwestern University; Estados UnidosFil: Copits, Bryan A.. University of Washington; Estados UnidosFil: Rogers, John A.. Northwestern University; Estados UnidosFil: Gereau, Robert W.. Washington University in St. Louis; Estados UnidosFil: Samineni, Vijay K.. University of Washington; Estados UnidosFil: Bandodkar, Amay J.. No especifíca;Fil: Gutruf, Philipp. University of Arizona; Estados Unido