Nanopartículas Poliméricas en Dermocosmética

Indexación: Web of Science; Scielo.Recent advances in the fields of biomaterials and nanotechnology have allowed the development of advanced nanoparticles for biomedical applications. Despite a vast number of nanostructures such as liposomes, solid­lipid nanocapsules, polymeric and hybrid lipid­polymer nanoparticles have been studied as carriers for drug delivery for different pathologies with remarkable promising results; the use of polymeric nanoparticles in dermocosmetic still has not been widely explored. The evolution of cosmetic into the care skin and dermatology represents novel technological challenges. Also, the increasing knowledge about normal skin physiology and advances in nanotechnology provide an attractive environment for the creation of innovative dermocosmetic formulations. In this work, we discuss the state of the art of polymeric nanoparticles formulated for dermocosmetics, its mechanisms of action, and diffusion into the skin.Los recientes avances en el campo de los biomateriales y la nanotecnología han permitido el desarrollo de nanopartículas avanzadas para aplicaciones biomédicas. A pesar de que un gran número de nanoestructuras tales como liposomas, nanocápsulas lípido-sólidas, nanopartículas poliméricas y lípido-polímero híbridas han sido estudiadas como vehículos para la administración de fármacos en diferentes patologías con notables resultados prometedores, el uso de nanopartículas poliméricas en dermocosmética todavía no ha sido ampliamente explorado. La evolución de la cosmética en el cuidado de la piel y la dermatología nos enfrentan a nuevos retos tecnológicos. Además, el aumento de los conocimientos sobre la fisiología de la piel normal y los avances en la nanotecnología proporcionan un entorno atractivo para la creación de formulaciones dermocosméticas innovadoras. En este trabajo se discute el estado del arte de las nanopartículas poliméricas desarrolladas para dermocosmética, sus mecanismos de acción y la difusión en la piel.http://ref.scielo.org/b68hz

Diputacions : l’ens qüestionat

Treball Final de Grau en Periodisme. Codi: PE0932.Curs: 2014/2015Es presenta un reportatge que aprofundeix sobre l’administració provincial i les diputacions provincials. El reportatge desenvolupa el debat sobre la utilitat, avantatges i problemes de les diputacions provincials en l’actualitat. Aquesta discussió ha estat present en els darrers anys a l’esfera política i social. Des de l’any 2011, aquest debat es va fer més patent, quan en el moment més crític de la crisi econòmica, molts partits polítics van analitzar el funcionament de les diputacions i es van posicionar. El debat sobre l’eficàcia i la utilitat de les diputacions provincials inclou diferents temes, com el seu funcionament, la seva eficàcia i el seu futur. El reportatge ofereix diferents punts de vista de la situació actual de les diputacions mitjançant entrevistes de càrrecs polítics que han treballat per a l’administració i l’opinió experta d’un professor de dret que analitza aquesta administració.A report that involves the debate of the provincial administration and the provincial government. This report develops the debate about the usefulness, advantages and problems of the provincial government nowadays. The discussion about the utility of the provincial administration has been present regularly in the political and social sphere. Since 2011 it became more relevant when in the most critical moment of the economic crisis, political parties analyzed the situation of the administration. The debate over the usefulness and utility of the provincial administration covers several topics, such its functioning, their efficiency and its future. The report offers different points of view on the current situation of the provincial government with interviews to politicians who have worked in the administration and the expert opinion of a law professor that gives an outlook of the regional administrations

Sequential model predictive control of three-phase direct matrix converter

© 2019 by the authors. The matrix converter (MC) is a promising converter that performs the direct AC-to-AC conversion. Model predictive control (MPC) is a simple and powerful tool for power electronic converters, including the MC. However, weighting factor design and heavy computational burden impose significant challenges for this control strategy. This paper investigates the generalized sequential MPC (SMPC) for a three-phase direct MC. In this control strategy, each control objective has an individual cost function and these cost functions are evaluated sequentially based on priority. The complex weighting factor design process is not required. Compared with the standard MPC, the computation burden is reduced because only the pre-selected switch states are evaluated in the second and subsequent sequential cost functions. In addition, the prediction model computation for the following cost functions is also reduced. Specifying the priority for control objectives can be achieved. A comparative study with traditional MPC is carried out both in simulation and an experiment. Comparable control performance to the traditional MPC is achieved. This controller is suitable for the MC because of the reduced computational burden. Simulation and experimental results verify the effectiveness of the proposed strategy

Investigation of Grid-Connected and Islanded Direct Matrix Converter for Renewable Microgrid Applications with Model Predictive Control

© 2018 IEEE. The direct matrix converter has been proposed for many potential applications. However, it remains unexplored within the context of microgrids and distributed generation. This paper investigates the application of the direct matrix converter to these areas. Both the grid-connected and islanded operation modes are explored. Model predictive control is employed to achieve flexible active and reactive power regulation in the grid-connected mode, and stable sinusoidal voltage control in the islanded mode. It is also used to achieve grid voltage synchronization prior to grid connection. Simulation and experimental results verify the feasibility and effectiveness of the direct matrix converter when used in grid-connected and islanded microgrids. When used in the matrix converter-connected microgrid, model predictive control is effective in regulating the voltage and the power exchange with the grid

Sequential model predictive control of direct matrix converter without weighting factors

© 2018 IEEE. The direct matrix converter (MC) is a promising converter that performs direct AC-to-AC conversion. Model predictive control (MPC) is a simple and powerful control strategy for power electronic converters including the MC. However, weighting factor design and heavy computational burden impose significant challenges for this control strategy. This paper investigates the sequential MPC (SMPC) for a three-phase direct MC. In this control strategy, each control objective has an individual cost function and these cost functions are evaluated sequentially based on priority. The complex weighting factor design process is not required and the computational burden can be reduced. In addition, specifying the priority for control objectives can be achieved. A comparative simulation study with standard MPC is carried out in Matlab/Simulink. Control performance is compared to the standard MPC and found to be comparable. Simulation results verify the effectiveness of the proposed strategy

Predictive Voltage Control of Direct Matrix Converters with Improved Output Voltage for Renewable Distributed Generation

© 2013 IEEE. This paper proposes a predictive voltage control strategy for a direct matrix converter used in a renewable energy distributed generation (DG) system. A direct matrix converter with LC filters is controlled in order to work as a stable voltage supply for loads. This is especially relevant for the stand-alone operation of a renewable DG where a stable sinusoidal voltage, with desired amplitude and frequency under various load conditions, is the main control objective. The model predictive control is employed to regulate the matrix converter so that it produces stable sinusoidal voltages for different loads. With predictive control, many other control objectives, e.g., input power factor, common-mode voltage, and switching frequency, can be achieved depending on the application. To reduce the number of required measurements and sensors, this paper utilizes observers and makes the use of the switch matrices. In addition, the voltage transfer ratio can be improved with the proposed strategy. The controller is tested under various conditions including intermittent disturbance, nonlinear loads, and unbalanced loads. The proposed controller is effective, simple, and easy to implement. The simulation and experimental results verify the effectiveness of the proposed scheme and control strategy. This proposed scheme can be potentially used in microgrid applications

Synthesis and characterization of polypiridine-based rhenium(I) complexes with pyrazino[2,3-f][1,10]phenanthroline

A series of tricarbonyl rhenium(I) complexes of the type fac-[Re 1(CO)3(Ppl)(L)]0/+, where ppl is pyrazino[2,3-f][1,10]phenanthroline, and where L is Cl-, TIO -, 4-(tert-butyl)pyridine (tBu-py), 4-methoxypyridine (MeO-py), 4,4′-bipyridyl (bpy), or 10-(picolin-4-yl)phenothiazine (pptz), were synthesized and fully characterized. In all complexes, an increment in the electron-acceptor properties of ppl compared to the free ligand was observed. This effect was more significant for pyridine-type ligands, especially for pptz, compared to Cl- or TfO-. The properties of fac-[Re(CO)3(ppl)(pptz)]PF6 were compared with those of the analogous compound fac-[Re(CO)3(dppz)(pptz)]PF6, where dppz is dipyrido(3,2-a: 2′,3′-c)phenazine, the goal being to generate long-lived excited charge-transfer (CT) states. In this respect, fac-[Re(CO)3(ppl)(pptz)]PF6 seems to be a promising candidate

Arachidonic acid and eicosapentaenoic acid metabolism in juvenile Atlantic Salmon as affected by water temperature

Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad-time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature recorded a significantly increased feed intake, these results clearly suggested that at high, sub-optimal water temperature, fish metabolism attempted to increment its overall ARA status -the most bioactive LC-PUFA participating in the inflammatory response- by modulating the metabolic fate of dietary ARA (expressed as % of net intake), reducing its β-oxidation and favouring synthesis and deposition. This correlates also with results from other recent studies showing that both immune- and stress- responses in fish are up regulated in fish held at high temperatures. This is a novel and fundamental information that warrants industry and scientific attention, in consideration of the imminent increase in water temperatures, continuous expansion of aquaculture operations, resources utilisation in aquafeed and much needed seasonal/adaptive nutritional strategies

Caracterizaci\uf3n del holoparasitismo de Orobanche ramosa en tomate bajo condiciones de campo

Field studies were conducted between 1999 and 2002, in Angol, Chile (37\ub045 ' S, 72\ub044 ' W) to determine the phenology of the system Orobanche ramosa \u2013 tomato ( Lycopersicon esculentum Mill.), to characterize the influence of holoparasitism on the growth and development of the host and the productive response at three planting dates (early, normal and delayed). The O. ramosa phenology includes underground and aerial phases, defining a total of six development stages: "a":: nodule; "b": nodule with initial crown roots; "c": shoot bud already visible; "d": shoot bud and crown root developed; "e": shoot development; and "f": shoot emerged from soil surface. The underground phase began with the establishment of the parasite, the first phenological event (stage "a":) being detected between 120 to 250 degree-days (DG), and the aerial phase (stage "f":) began when 550 DG of thermal requirements was surpassed. These phases occurred at flowering and fruit set of the host, respectively. The mean life cycle of the system O. ramosa - tomato was completed with 1,180 DG or 132 days after planting (DDT). Parasitism of O. ramosa altered morphological parameters and the distribution of dry matter in the host before the emergence of O. ramosa, the aerial components being most effected. It translated into important losses of production at the planting dates, which varied between 77 and 81%. Therefore, advancing or delaying the planting date does not constitute an efficient cultural practice for tomato fields to escape O. ramosa parasitism.Se realizaron estudios de campo entre 1999 y 2002, en Angol, Chile (37\ub045' lat. Sur, 72\ub044' long. Oeste) para determinar la fenolog\ueda del complejo orobanque-tomate ( Orobanche ramosa L.- Lycopersicon esculentum Mill.), caracterizar la influencia del holoparasitismo en el crecimiento y desarrollo del hospedero, y la respuesta productiva en tres \ue9pocas de plantaci\uf3n (temprana, normal y tard\ueda). La fenolog\ueda de O. ramosa comprende una fase subterr\ue1nea y otra a\ue9rea, defini\ue9ndose un total de seis estados de desarrollo: "a": n\uf3dulo; "b": n\uf3dulo con ra\uedz de escaso desarrollo; "c": aparici\uf3n de yema; "d": yema y ra\uedz desarrollada; "e": v\ue1stago desarrollado; y "f": v\ue1stago emergiendo sobre la superficie del suelo. La fase subterr\ue1nea se inici\uf3 con el establecimiento del fitopar\ue1sito, detect\ue1ndose el primer evento fenol\uf3gico (estado "a") entre 120 a 250 d\uedas grado (DG), y la fase a\ue9rea (estado "f") comenz\uf3 cuando se super\uf3 los 550 DG de requerimientos t\ue9rmicos. Dichas fases coincidieron con la floraci\uf3n y fructificaci\uf3n del hospedero, respectivamente. El ciclo de vida promedio de O. ramosa se complet\uf3 con 1.180 DG \uf3 132 d\uedas despu\ue9s del trasplante (DDT). El parasitismo alter\uf3 par\ue1metros morfol\uf3gicos y distribuci\uf3n de la materia seca en el hospedero antes de la emergencia de O. ramosa, siendo el componente a\ue9reo (follaje) el m\ue1s afectado. Ello se tradujo en importantes p\ue9rdidas de producci\uf3n en las \ue9pocas de plantaci\uf3n, las que variaron entre 77 y 81%. Por lo tanto, adelantar o retrasar la plantaci\uf3n de tomate no constituye una pr\ue1ctica cultural eficiente para escapar al efecto del parasitismo de O. ramosa