RESUMO
Urban vertical agriculture with lighting system can be an alternative green infrastructure to increase local food production irrespective of environmental and soil conditions. In this system, light quality control can improve the plant physiological performance, well as induce metabolic pathways that contribute to producing phenolic compounds important to human health. Therefore, this study aimed to evaluate the influence of RBW (red, blue and white) and monochromatic (red and blue; R and B, respectively) light associated or not with UV-B on photosynthetic performance and phenolic compound production in microtomato fruits cultivated via vertical agriculture. The experimental design adopted was completely randomized, with six replicates illuminated with 300 µmol·m-2·s-1 light intensities (RBW, RBW + UV, B, B + UV, R, and R + UV), 12 h photoperiod, and 3.7 W·m-2 UV-B irradiation for 1 h daily for the physiological evaluations. Twenty-six days after the installation, gas exchange, chlorophyll a fluorescence and nocturnal breathing were evaluated. Fruits in different ripening stages (green, orange, and red) were collected from microtomato plants grown under with different light qualities, to evaluate the physiological performance. The identification and quantification of the phenolic compound rutin was also performed to investigate their metabolic response. This study identified that plants grown under B + UV had high photosynthetic rates (A=11.57 µmol·m-2·s-1) and the fruits at all maturation stages from plants grown under B and B + UV had high rutin content. Meanwhile, the activation of suppressive mechanisms was necessary in plants grown under R because of the high nocturnal respiration and unregulated quantum yield of the non-photochemical dissipation of the photosystem II. These results highlight the importance of selecting light wavelength for vegetable cultivation to produce fruits with a high content of specialized metabolites that influence color, flavor, and health promotion, which is of special interest to farmers using sustainable cropping systems.
RESUMO
Pinus. ponderosa (P. Lawson and C. Lawson) is a commercial tree and one of the most important forest species in North America. Ponderosa pine suffers hardship when going through vegetative propagation and, in some cases, 15-30 years are needed to achieve full reproductive capacity. Based on previous works on P. ponderosa regeneration through in vitro organogenesis and trying to improve the published protocols, our objective was to analyze the influence of different types of explants, basal culture media, cytokinins, auxins, and light treatments on the success of shoot multiplication and rooting phases. Whole zygotic embryos and 44 µΜ 6-benzyladenine showed the best results in terms of explants survival. For shoot organogenesis, whole zygotic embryos and half LP (LP medium, Quoirin and Lepoivre, 1977, modified by Aitken-Christie et al., 1988) macronutrients were selected. A significant positive interaction between whole zygotic embryos and half LP macronutrients was found for the percentage of explants forming shoots. Regarding the light treatments applied, a significantly higher percentage of shoots elongated enough to be rooted was detected in shoots growing under blue LED at a light intensity of 61.09 µmol m-2 s-1. However, the acclimatization percentage was higher in shoots previously cultivated under fluorescent light at a light intensity of 61.71 µmol m-2 s-1. Anatomical studies using light microscopy and scanning electron microscopy showed the light treatments promoted differences in anatomical aspects in in vitro shoots; needles of plantlets exposed to red and blue LEDs revealed less stomata compared with needles from plantlets exposed to fluorescent light.
RESUMO
Phlebotomine sand flies are responsible for the transmission of different pathogens, including flagellate protozoan of the genus Leishmania. To locate a vertebrate host, females use chemical cues called kairomones, which are also used by males and females to locate carbohydrate sources of food. In addition to these chemical cues, visual cues (such as light and color) can play a key role in determining host location. In this way, incandescent white light is widely used to capture these insects in the field, being more recently replaced by light-emitting diode (LEDs) technology, which can be used with different colors. In this review, we summarize the main results of the use of LEDs as attractants for sand flies. Considering the different LEDs colors, blue and green are responsible for catching the highest number of sand fly species, especially for field trials conducted in New World countries. The intensity of light colors is an important factor to be considered, but so far little explored. In general, the use of LEDs can be considered as a feasible tool for the improvement of light traps. Future research is required to assert the contribution of different colors individually, in different combinations and intensities, as well as the possible synergistic effect of LEDs in association with attractive compounds in the behavior of sand flies.
Assuntos
Leishmania , Phlebotomus , Psychodidae , Masculino , Animais , Feminino , Luz , FeromôniosRESUMO
Objective: We report on the development and characterization of a UV-C light-emitting diode (LED) 280 nm cluster prototype device designed for the rapid disinfection of SARS-CoV-2 coronaviruses. The device was evaluated against the Betacoronavirus mouse hepatitis virus-3 strain, and its virucidal capacity was probed as a function of different applied UV-C doses versus different situations concerning irradiation distances. Background: UV-C LEDs are light emitters that offer advantages over low-pressure mercury lamps, such as quasimonochromaticity, lower electrical power consumption, instant on/off with the instant full-power operation, unlimited on/off cycles for disinfection schemes, and a much longer lifetime operation, in addition to portability aspects, as well as UV-C LEDs do not contain heavy metal in its composition such as mercury, found in ultraviolet germicidal irradiation (UVGI) lamps. Results: This novel device reached a 99.999% elimination rate at a distance of 9 cm at all the tested irradiation times (dose dependence), demonstrating that it took only 30 sec to achieve this inactivation rate. Its virucidal effectivity in rapid virus inactivation was demonstrated. Conclusions: We conclude that the HHUVCS cluster device (λp = 280 nm) provides a rapid virucidal effect against the SARS-CoV-2 coronavirus. The current research should encourage further advances in UV-C LED-based devices designed for the inactivation of SARS-CoV-2 virus on surfaces, in air, and in liquids.
Assuntos
COVID-19 , Mercúrio , Animais , Desinfecção , Camundongos , SARS-CoV-2 , Raios UltravioletaRESUMO
Researches about light emitting diodes (LEDs) as energy source in microalgae cultivations has been growing in recent years due to its spectral quality, durability and reduced energy consumption. In this study, green, red and yellow LEDs were evaluated as energy source in Synechococcus nidulans LEB 115 cultures. Productivities and specific growth rates were up to 2.5 times greater than in cultures using fluorescent light. The different LED colors evaluated did not influence the chlorophyll, carotenoid or lipid productions. Biomass cultivated with LEDs showed high amounts of saturated fatty acids (above 48%), which is desirable for biodiesel production. In addition to the Synechococcus nidulans LEB 115 growth stimulation, the application of green, red and yellow LEDs in the cultivations produces potential biomass for biodiesel synthesis and other industrial interest biomolecules utilization.
Assuntos
Carotenoides/biossíntese , Clorofila/biossíntese , Lipídeos/análise , Synechococcus/metabolismo , Biocombustíveis , Biomassa , Cor , Luz , Lipídeos/biossíntese , Microalgas/metabolismo , Pigmentação , Synechococcus/crescimento & desenvolvimentoRESUMO
Plant-phyllosphere interactions depend on microbial diversity, the plant host and environmental factors. Light is perceived by plants and by microorganisms and is used as a cue for their interaction. Photoreceptors respond to narrow-bandwidth wavelengths and activate specific internal responses. Light-induced plant responses include changes in hormonal levels, production of secondary metabolites, and release of volatile compounds, which ultimately influence plant-phyllosphere interactions. On the other hand, microorganisms contribute making some essential elements (N, P, and Fe) biologically available for plants and producing growth regulators that promote plant growth and fitness. Therefore, light directly or indirectly influences plant-microbe interactions. The usage of light-emitting diodes in plant growth facilities is helping increasing knowledge in the field. This progress will help define light recipes to optimize outputs on plant-phyllosphere communications. This review describes research advancements on light-regulated plant-phyllosphere interactions. The effects of full light spectra and narrow bandwidth-wavelengths from UV to far-red light are discussed.
RESUMO
BACKGROUND: In this work, a drug product composed of an IgM antibody derived from a hybridoma subclone 4C1F6D5G7B8 was prepared and further labeled with PpIX to be used in cell lines A-549 and MRC-5. The aim of this work was to evaluate the potential theranostic activity of the obtained product together with photodynamic therapy (PDT). METHODS: The IgM antibody labeled with PpIX was used in different concentrations to perform theranostics with PDT in cell lines A-549 and MRC-5 in order to identify the specificity of IgM antibody in lung cancer cells by means of a LED-irradiation system set at 630â¯nm. The location of the conjugate was further determined by confocal microscopy. RESULTS: The theranostic with conjugate Ab-PpIX in the A-549 cell lines showed fluorescence by confocal microscopy, whereas the MRC-5 cell line showed no reactivity. The PDT with the conjugate in the cell line A-549 decreased its viability 70% compared to the control. On the contrary, with the MRC-5 cell line no viability diference was shown. The confocal microscopy applied to the cell line A-549 showed that the Ab-PpIX was majorly located at the cytoplasm. CONCLUSION: Ab-PpIX showed therapeutical potential in lung cancer cells A-549 and had no activity in non-cancerous lung cells (MCR-5).
Assuntos
Imunoconjugados/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Protoporfirinas/farmacologia , Nanomedicina Teranóstica/métodos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Imunoglobulina M , Imunoglobulinas , Queratinas/metabolismo , Superóxido Dismutase/metabolismoRESUMO
This study evaluated light emitting diodes (LEDs) as a light source in Spirulina sp. LEB 18 cultures in terms of growth parameters and biomass composition. Different photoperiods (partial and integral) and colors (blue, green, red and white) were assessed. Blue, green, red and white LEDs increased biomass productivity and maximum specific growth rate of such cultivations. The maximum biomass concentration (1.77⯱â¯0.02â¯gâ¯L-1) was obtained when red LEDs in integral light photoperiod were applied to cultivations. The biomass composition showed around 12.8% carbohydrates (wâ¯w-1), 57.4% proteins (wâ¯w-1) and 12.7% lipids (wâ¯w-1). The major fatty acids produced during cultivations were palmitic, linoleic and γ-linolenic. Green LEDs in partial light photoperiod promoted a higher concentration of phycocyanin (126.39â¯mgâ¯gbiomass-1). The potential of LEDs as an energy source in Spirulina sp. LEB 18 cultures was demonstrated by the biomass and bioproducts photostimulation.
Assuntos
Fotossíntese , Ficocianina , Spirulina , Biomassa , LuzRESUMO
RESUMEN En este proyecto se diseñó y construyó un prototipo con potencial aplicación a un sistema de fototerapia para ictericia neonatal utilizando por primera vez LEDs de 10 W de alta potencia. Se describe la metodología aplicada para el diseño de los diferentes circuitos electrónicos que se utilizaron para la alimentación de la corriente de excitación de los LEDs, se describe el método de control de corriente mediante el uso de la modulación por ancho de pulsos, Pulse Width Modulation (PWM, por sus siglas en inglés), generados por el circuito integrado 555. Se diseñó la placa de circuito impreso mediante la ayuda del simulador Orcad Layout. Se utilizaron dos LEDs de alta potencia de 10 W para el propósito de conservar la intensidad requerida para el tratamiento, minimizando el espacio utilizado por la cantidad de LEDs utilizados en los equipos convencionales. Entre las limitaciones que se presentaron en esta investigación fue el uso de la plataforma Arduino, ya que se tienen varias oportunidades de mejora para darle el mejor uso al microcontrolador, y de esta manera digitalizar el sistema de una forma más completa, reduciendo la circuitería de control. El prototipo presentado cumple con los requerimientos necesarios para un sistema de fototerapia.
ABSTRACT This project consisted in the design and construction of a prototype with potential application to a phototherapy system for neonatal jaundice using for the first-time high power 10 W LEDs. The methodology for the design of different electronic circuits which were used for feeding the drive current of the LEDs, the current control method described using pulse width modulation (PWM) generated by the known 555 integrated circuit is described. The printed circuit board was designed with the help of the Orcad Layout simulator. Two high-power 10 W LEDs were used for maintaining the intensity required for the treatment, minimizing the space used by the number of LEDs used in the conventional equipment. Among the limitations presented in this research was the use of the Arduino platform, due to several improve that can be used to improve and increase the use of this microcontroller, and in this way to digitize the system, reducing the circuitry of control. The prototype presented meets the requirements for a phototherapy system according to the different references used.
RESUMO
This research work objective was to optimize the micropropagation of potato cultivars through the use of new light sources in the growth rooms. Treatments consisted of three potato cultivars (Asterix, Catucha and Macaca), and five light sources (blue, green and red LEDs; Growlux and white fluorescent lamps). The explants consisted of nodal segments containing one bud, isolated from plantlets grown in vitro. The experimental design was completely randomized arranged in a 3x5 factorial, with eight replications. Each experimental unity consisted of a flask with five explants. Three 28-day consecutive subcultures were carried out in MS semi-solid medium, in growth-room under controlled conditions (temperature = 25+2 ºC; photoperiod = 16 hours; light intensity = 20 µmol m-2 s-1). At the end of each subculture, the bud number per plantlet, plantlet length and internode length were evaluated. After the third subculture, the concentrations of carotenoids and a- and b-chlorophylls were also determined. Different micropropagation efficiencies were found among potato cultivars grown in vitro conditions: 'Macaca' was the most and 'Catucha' the least responsive cultivar. The growth room light sources differently affected the potato plantlet development: red and green LEDs were the most and least recommended for plantlet development, based on the results of bud number per plantlet, plantlet length, and leaflet concentrations of a- and b-chlorophylls and carotenoids.
Este trabalho objetivou otimizar a micropropagação de cultivares de batata por meio do uso de novas fontes de luz no ambiente de cultivo. As cultivares avaliadas foram Asterix, Catucha e Macaca e as fontes de luz foram LEDs azuis, LEDs verdes, LEDs vermelhos, lâmpadas Growlux e lâmpadas fluorescentes brancas. Como explantes foram utilizados segmentos nodais contendo uma gema, isolados de brotações estabelecidas in vitro. O delineamento experimental foi inteiramente ao acaso em um fatorial 3 x 5 (cultivar x fonte de luz), com oito repetições por tratamento. Cada unidade experimental foi composta por um frasco contendo cinco explantes. O experimento compreendeu três subcultivos consecutivos de 28 dias em meio semi-sólido MS a 25+2 ºC, 16 horas de fotoperíodo e intensidade luminosa de 20 µmol m-2 s-1. Ao final de cada subcultivo foram avaliados o número de gemas produzidas por explante, o comprimento das brotações e o comprimento dos entrenós. Ao final do terceiro subcultivo, determinaram-se, ainda, as concentrações de carotenoides e de clorofilas a e b. Verificou-se efeito da cultivar na eficiência do processo de propagação de batata, sendo a 'Macaca' a mais e a 'Catucha' a menos responsiva in vitro. A fonte de luz do ambiente de cultivo afetou o desenvolvimento dos explantes de batata. Os LEDs vermelhos e os verdes foram, respectivamente, os mais e os menos indicados tanto para o desenvolvimento vegetativo quanto para a formação de clorofilas a e b e de carotenoides.