63 research outputs found
3D structures based on carbón materials and conducting polymers for electroresponsive cell cultures
149 p.El campo de la ingeniería de tejidos (TE) requiere la generación de nuevas plataformas tridimensionales como implantes o materiales tridimensionales para estudios de modelos. Dentro de todos los tejidos, nosotros nos hemos enfocado en aquellos que se ven favorecidos cuando están crecidos sobre un entorno electroactivo, tales como el tejido neuronal o cardíaco. Para que estas estructuras cumplan todos los requisitos y mimeticen el tejido nativo se requieren propiedades mecánicas blandas, conductividad, porosidad controlada y biocompatibilidad.Esta tesis doctoral ha abordado el desafío de fabricar estructuras 3D con el polímero conductor PEDOT, que carece de posibilidad de formar estructuras 3D por él mismo, usando otros materiales auxiliares para conseguirlo. De esta manera, en el primer y segundo capítulo de la tesis se han desarrollado estructuras tidimensionales de PEDOT y nanotubos de carbono (CNT) usando metodologías comúnmente utilizadas para formar estructuras bidimensionales tipo films. Estas estructuras han sido caracterizadas mostrando excelente conductividad, propiedades mecánicas ideales para cultivo neuronal, porosidad y buena biocompatibilidad. Por último, se ha diseñado un material conductor e imprimible por impresión 3D, formado por un poliéster común (PLA) y PEDOT. Ambos en conjunto poseen buena biocompatibilidad y la posibilidad de madurar tejido cardíaco, generando durante su co-cultivo estructuras de la matriz extracelular que permiten al cardiomiocito latir y por lo tanto mantener su funcionalidad.Polymat
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Recent Advances on 2D Materials towards 3D Printing
In recent years, 2D materials have been implemented in several applications due to their unique and unprecedented properties. Several examples can be named, from the very first, graphene, to transition-metal dichalcogenides (TMDs, e.g., MoS2), two-dimensional inorganic compounds (MXenes), hexagonal boron nitride (h-BN), or black phosphorus (BP). On the other hand, the accessible and low-cost 3D printers and design software converted the 3D printing methods into affordable fabrication tools worldwide. The implementation of this technique for the preparation of new composites based on 2D materials provides an excellent platform for next-generation technologies. This review focuses on the recent advances of 3D printing of the 2D materials family and its applications; the newly created printed materials demonstrated significant advances in sensors, biomedical, and electrical applications.Financial support from Operational Program Research, Development and Education-Project “MSCAfellow4@MUNI” (CZ.02.2.69/0.0/0.0/20_079/0017045) is acknowledged
2D and 3D Immobilization of Carbon Nanomaterials into PEDOT via Electropolymerization of a Functional Bis-EDOT Monomer
Carbon nanomaterials (CNMs) and conjugated polymers (CPs) are actively investigated in applications such as optics, catalysis, solar cells, and tissue engineering. Generally, CNMs are implemented in devices where the relationship between the active elements and the micro and nanostructure has a crucial role. However, they present some limitations related to solubility, processibility and release or degradability that affect their manufacturing. CPs, such as poly(3,4-ethylenedioxythiophene) (PEDOT) or derivatives can hide this limitation by electrodeposition onto an electrode. In this work we have explored two different CNMs immobilization methods in 2D and 3D structures. First, CNM/CP hybrid 2D films with enhanced electrochemical properties have been developed using bis-malonyl PEDOT and fullerene C60. The resulting 2D films nanoparticulate present novel electrochromic properties. Secondly, 3D porous self-standing scaffolds were prepared, containing carbon nanotubes and PEDOT by using the same bis-EDOT co-monomer, which show porosity and topography dependence on the composition. This article shows the validity of electropolymerization to obtain 2D and 3D materials including different carbon nanomaterials and conductive polymers.This research was funded by the Spanish Ministry of Economy and Competitiveness MINECO (project CTQ2016-76721-R), the University of Trieste, Diputación Foral de Gipuzkoa program Red (101/16), the European Commission (H2020-MSCA-RISE-2016, grant agreement no. 734381, acronym CARBO-IMmap) and ELKARTEK bmG2017 (ref: Elkartek KK-2017/00008, BOPV resolution: 8 Feb 2018). M.P., as the recipient of the AXA Chair, is grateful to the AXA Research Fund for financial support. This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency Grant no. MDM-2017-0720. N.A. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 753293, acronym NanoBEAT
Additive Manufacturing of Conducting Polymers: Recent Advances, Challenges and Opportunities
Unformatted postprintConducting polymers (CPs) have been attracting great attention in the development of (bio)electronic devices. Most of current devices are rigid 2D systems and possess uncontrollable geometries and architectures that lead to poor mechanical properties presenting ion/electronic diffusion limitations. The goal of the article is to provide an overview about the additive manufacturing (AM) of conducting polymers, which is of paramount importance for the design of future wearable 3D (bio)electronic devices. Among different 3D printing AM techniques, inkjet, extrusion, electrohydrodynamic and light-based printing have been mainly used. This review article collects examples of 3D printing of conducting polymers such as poly(3,4-ethylene-dioxythiophene) (PEDOT), polypyrrole (PPy) and polyaniline (PANi). It also shows examples of AM of these polymers combined with other polymers and/or conducting fillers such as carbon nanotubes, graphene and silver nanowires. Afterwards, the foremost application of CPs processed by 3D printing techniques in the biomedical and energy fields, i.e., wearable electronics, sensors, soft robotics for human motion, or health monitoring devices, among others, will be discussed.This work was supported by Marie Sklodowska-Curie Research and Innovation Staff Exchanges (RISE) under the grant agreement No 823989 “IONBIKE”. N.A. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 753293, acronym NanoBEAT
Intrinsic and Selective Activity of Functionalized Carbon Nanotube/Nanocellulose Platforms Against Colon Cancer Cells
[Abstract] Given their large surface area and versatile chemical reactivity, single-walled carbon nanotubes (SWCNTs) are regarded as the basis of new pharmacological complexes. In this study, SWCNTs are chemically functionalized with fluorescein, folic acid, and capecitabine, a drug that is commonly used against colorectal cancer. These functionalized SWCNTs are dispersed in water by taking advantage of their synergistic interaction with type-II nanocrystalline cellulose (II-NCC), and the resulting colloidal system is tested in vitro on both normal (differentiated) and cancerous (proliferative) human colon cells (Caco-2). The functionalized SWCNT/II-NCC hybrids show a higher activity than the reference (capecitabine) against the Caco-2 cancer cell line. However, this effect appears to be intrinsically associated with the SWCNT/II-NCC complex, particularly boosted by fluorescein, as the presence of capecitabine is not required. In addition, confocal microscopy fluorescence imaging using cell cultures highlights the enormous potential of this nanohybrid platform for colon cancer theranostics.This research was funded by the regional government of Aragón, DGA (Grupos Reconocidos DGA-T03_17R, DGA-T03_20R and DGA-A20_20R), together with associated EU Regional Development Funds, and also the Spanish MINEICO through a “Juan de la Cierva Incorporación” contract, and their associated research funds (ref. IJCI-2016–27789). A.C. thanks the Xunta de Galicia for an “Atracción de Talento” research grant (no. ED431H 2020/17)Gobierno de Aragón; DGA-T03_17RGobierno de Aragón; DGA-T03_20RGobierno de Aragón; DGA-A20_20RXunta de Galicia; ED431H 2020/1
Preparación, caracterización y estudio morfológico de fibras de carbón activado
Utilizando fibras de kenaf larga, se ha llevado a cabo la preparación, caracterización y estudio morfológico de las fibras de carbón activado (ACFs). La caracterización era realizada mediante las isotermas de adsorción de N2 a -196 C, porosimetría de Hg y microscopia electrónica de barrido. La activación a 700 ºC con CO2 durante 2h (FBC4A72) y 4 h (FBC4A74) de la muestra carbonizada a 400 ºC durante 0.5 h en N2 (FBC4), mostraban un incremento en el tamaño del poro, como se observa en las microscopías electrónica de barrido. Esto es probablemente debido a la interconexión de los poros como consecuencia del incremento del tiempo de tratamiento de 2 a 4h. Estos resultados abren un amplio campo de aplicación para las fibras de kenaf.Using kenaf as starting material, a study about the preparation and characterization of activated carbon fibers (ACFs) from long fibers was carried out. The carbonization products of kenaf fibers and ACFs
were texturally characterized by N2 adsorption at -196 ºC, mercury porosimetry, and scanning electron microscopy. The activation of the raw material of Kenaf by its carbonization at 400 ºC for 0.5 h in a N2 atmosphere increase the porosity of the samples, particularly the activation at 700 ºC with carbon dioxide. It should be noted the porous development shown by the scanning electron micrographs of samples FBC4A72 and FBC4A74. It is observed that the variation of treatment time from 2 to 4 hours leads to an important
development of the porous structure in samples FBC4A74, which is probably a consequence of an interconnection between pores. These results open a wide field of applications of these fibers.peerReviewe
Reconocimiento, medición, presentación, información a revelar y tratamiento tributario del contrato de opción de venta de maíz blanco, utilizado por las Asociaciones Privadas de Interés Social del departamento de San Vicente, a implementarse en el año 2019.
La presente investigación está enfocada en proponer una guía de aplicación sobre el Reconocimiento, medición, presentación, información a revelar y el tratamiento tributario del contrato de opción de venta de maíz blanco, utilizado por las asociaciones privadas de interés social del departamento de San Vicente.
La idea de una guía surge debido a que en El Salvador existe una limitada cantidad de información sobre las opciones financieras en cuanto al tratamiento financiero respecta. Es por ello que, como grupo de investigación se tomó como referente el contrato de opción de venta negociado en
BOLPROS como objeto de estudio, si bien es cierto que no se cuenta con un mercado de derivados financieros en nuestro país, su naturaleza lo convierte en un instrumento financiero cuyo tratamiento es diferente al de los instrumentos financieros básicos.
El primer capítulo contiene los fundamentos teóricos del contrato de opción de venta, las asociaciones y la comercialización del maíz blanco en El Salvador.
El capítulo dos muestra el planteamiento del problema de investigación y la metodología empleada para la recopilación de datos que fundamentan la situación actual de los sujetos de estudio.
El tercer capítulo presenta la situación actual de los sujetos de investigación. En este se muestra como las asociaciones realizan el tratamiento financiero y tributario de las operaciones que surgen del contrato de opción de venta; así como, las conclusiones y recomendaciones producto de los instrumentos administrados a las asociaciones privadas de interés social.
En el cuarto capítulo se plantea una guía de aplicación que contiene las políticas contables basadas en la normativa financiera que deben aplicar las asaciones privadas de interés social; así como el tratamiento tributario del contrato de opción de venta de maíz blanco. También contiene el desarrollo de un caso práctico fundamentado en la política contable propuesta, con la finalidad de que los estados financieros muestren fielmente la realidad económica de las asociaciones que utilizan este tipo de contrato
Fast Visible-Light Photopolymerization in the Presence of Multiwalled Carbon Nanotubes: Toward 3D Printing Conducting Nanocomposites
[EN] A new photoinitiator system (PIS) based on riboflavin (Rf), triethanolamine, and multiwalled carbon nanobutes (MWCNTs) is presented for visible-light-induced photopolymerization of acrylic monomers. Using this PIS, photopolymerization of acrylamide and other acrylic monomers was quantitative in seconds. The intervention mechanism of CNTs in the PIS was studied deeply, proposing a surface interaction of MWCNTs with Rf which favors the radical generation and the initiation step. As a result, polyacrylamide/MWCNT hydrogel nanocomposites could be obtained with varying amounts of CNTs showing excellent mechanical, thermal, and electrical properties. The presence of the MWCNTs negatively influences the swelling properties of the hydrogel but significantly improves its mechanical properties (Young modulus values) and electric conductivity. The new PIS was tested for 3D printing in a LCD 3D printer. Due to the fast polymerizations, 3D-printed objects based on the conductive polyacrylamide/CNT nanocomposites could be manufactured in minutes.The authors are thankful for technical and human support provided by IZO-SGI SGIker of UPV/EHU. The authors would like to thank the European Commission for financial support through funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no. 823989
Digital Light 3D Printing of PEDOT-Based Photopolymerizable Inks for Biosensing
3D conductive materials such as polymers and hydrogels that interface between biology and electronics are actively being researched for the fabrication of bioelectronic devices. In this work, short-time (5 s) photopolymerizable conductive inks based on poly(3,4-ethylenedioxythiophene) (PEDOT):polystyrene sulfonate (PSS) dispersed in an aqueous matrix formed by a vinyl resin, poly(ethylene glycol) diacrylate (PEGDA) with different molecular weights (M-n = 250, 575, and 700 Da), ethylene glycol (EG), and a photoinitiator have been optimized. These inks can be processed by Digital Light 3D Printing (DLP) leading to flexible and shape-defined conductive hydrogels and dry conductive PEDOTs, whose printability resolution increases with PEGDA molecular weight. Besides, the printed conductive PEDOT-based hydrogels are able to swell in water, exhibiting soft mechanical properties (Young's modulus of similar to 3 MPa) similar to those of skin tissues and good conductivity values (10(-2) S cm(-1)) for biosensing. Finally, the printed conductive hydrogels were tested as bioelectrodes for human electrocardiography (ECG) and electromyography (EMG) recordings, showing a long-term activity, up to 2 weeks, and enhanced detection signals compared to commercial Ag/AgCl medical electrodes for health monitoring.This work was supported by Marie Sklodowska-Curie Research
and Innovation Staff Exchanges (RISE) under grant agreement
No. 823989 “IONBIKE”
Sistema informático para la gestión académica y administrativa del Colegio Ángeles Felices
El sistema informático para la gestión académica y administrativa del Colegio Ángeles Felices, es un sistema que le brinda al colegio la oportunidad de agilizar sus procesos del día a día y tener una mayor interacción con los padres de familia que les confían la educación de sus hijos, ya que estos serán usuarios del sistema. Cuenta con varios modelos los cuales se adoptan a los procesos que realizan, entre ellos están: gestión de alumnos, empleados, proveedores y compra, así como el manejo de caja chica y notificaciones, etc. Para ayudar a las toma de decisiones y las operaciones del colegio, el sistema cuenta con una variedad de reportes configurables. El sistema cuenta con flujos de aprobación, los cuales permite una buena interacción entre sus usuarios para cumplir a la perfección sus procesos. Tiene una interfaz funcional y adaptable, gestionada por el modelo de segurida
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