Estudo anatômico de trembleya phlogiformis dc.

v. 13, n. 2, p. 82-92, 2016.

Characterisation and environmental application of an Australian natural zeolite for basic dye removal from aqueous solution

An Australian natural zeolite was collected, characterised and employed for basic dye adsorption in aqueous solution. The natural zeolite is mainly composed of clinoptiloite, quartz and mordenite and has cation-exchange capacity of 120 meq/100 g. The natural zeolite presents higher adsorption capacity for methylene blue than rhodamine B with the maximal adsorption capacity of 2.8 x 10(-5) and 7.9 x 10(-5) Mot/g at 50 degrees C for rhodamine B and methylene blue, respectively. Kinetic studies indicated that the adsorption followed the pseudo second-order kinetics and could be described as two-stage diffusion process. The adsorption isotherm could be fitted by the Langmuir and Freundlich models. Thermodynamic calculations showed that the adsorption is endothermic process with Delta H degrees at 2.0 and 8.7 kJ/mol for rhodamine B and methylene blue. It has also found that the regenerated zeolites by high-temperature calcination and Fenton oxidation showed similar adsorption capacity but lower than the fresh sample. Only 60% capacity could be recovered by the two regeneration techniques. (c) 2006 Elsevier B.V. All rights reserved.

Influence of loggerhead egg agregation on survival: why does single eggs buried into natural sand dye in few days?

[EN] The incubation is an essential life period for oviparous species that very often experiences a high mortality. In some reptile species the number of eggs that develop together in the incubation chamber affects survival and hatchling phenotype. Sea turtle eggs develop in underground locations on sandy beaches in large masses that usually have more than 80 eggs. Natural egg mortality seems to vary among species and for the sensitive leatherbacks, external eggs seems to survive better than internal ones within the nest.

Spectroscopic characterization of natural dyes by their non-invasive identification on pre-Columbian codices: the Maya yellow

Mesoamerican cultures had a strong tradition of written and pictorial manuscripts, called the codices. In studies already performed it was found the use of Maya Blue, made from a mixture of indigo and a clay called palygorskite, forming an incredibly stable material where the dye is trapped inside the nanotubes of the clay, after heating. However, a bigger challenge lies in the study of the yellows used, for these civilizations might have used this clay-dye mixture to produce their yellow colorants. As a first step, it was possible to provide identification, by non-invasive methods, of two colorants (a flavonoid and a carotenoid). While the flavonoid absorbed between 368-379 nm, the carotenoid would absorb around 455 nm. A temperature study also conducted allowed to set 140ºC as the desirable temperature to heat the samples without degrading them. FT-IR, conventional Raman and SERS allowed us to understand the existence of a reaction between the dyes and the clays (palygorskite and kaolinite), however it is difficult to understand it in a molecular point of view. As a second step, five species of Mexican dyes were selected on the basis of historical sources. The Maya yellow samples were produced adapting the recipe proposed by Reyes-Valerio, supporting the yellow dyes extracted from the dried plants on the clays, with addition of water, and then heated at 140ºC. It was found that the addition of water in palygorskite would increase the pH, hence deprotonating the molecules having a clear negative effect in the color. A second recipe was developed, without the addition of water; however, it was found that the use of water based binders would still alter the color of the samples with palygorskite. In this case, kaolinite without heating yield better results as a Maya yellow hybrid. It was found that the Maya chemistry might not have been the same for all the colors. The Mesoamericans might have found that different dyes could work better to their desires if matched with different clays. It was noticeable that for a clear distinction between flavonoids and carotenoids the reflectance and emission studies suffice, but when clay is added, Raman techniques will perform better. For this reason, conventional Raman and SERS were employed in order to create a database for the Mesoamerican dyestuffs for a future identification.

Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

Identification and Characterization of Natural Anti-Breast Cancer Compound: Costunolide

Breast cancer is the most common cancer among women, 23% (1.3 million) of the total of new cases and the second leading cause of cancer death in women exceeded only by lung cancer. Natural medicines have been proven to be a central source of narrative agents with a pharmaceutical potential. Costunolide is sesquiterpene lactones consisting of diverse plant chemicals that exhibit anti cancer action through cytotoxic effects on various cancer cells. The objectives of present study were to explore the effects of natural compounds on the proliferation of MCF-7 cells and to determine the role of ROS in natural compounds-induced apoptosis in breast cancer cells with a therapeutic potential. Results showed that costunolide screened, possess potent anticancer properties against breast cancer MCF-7 cells, Costunolide was observed as strong anti-proliferative agent with IC50 = 50µM. The anti-proliferative effect of costunolide on MCF cells was confirmed by live/dead assay using fluorescent probes calcein AV/PI. The results demonstrated that treatment of cells with costunolide decreased the viability of MCF-7 cells in a dose-dependent manner. To determine the costunolide-induced apoptosis, flow cytometric analysis was carried out. The results showed that costunolide induced apoptosis in a dose-dependent manner in breast cancer MCF-7cells. ROS are well known mediators of intracellular signaling of cascades. The excessive generation of ROS can induce oxidative stress, loss of cell functioning, and apoptosis. In the present study, we assumed that costunolide might arouse ROS level, which could be involved in induction of apoptosis. Therefore, the intracellular ROS level was measured using the ROS-detecting fluorescence dye 2, 7-dichlorofluorescein diacetate (DCF-DA). Interestingly these effects were significantly abrogated when the cells were pretreated with N-acetyl- cysteine (NAC), a specific ROS inhibitor. Costunolide induces apoptosis through extrinsic pathway in MCF-7 breast cancer cells, In order to examine whether costunolide suppresses cell growth inducing apoptotic cell death, we analyzed DNA contents and apoptosis-related proteins expression level by flow cytometry and western blot, respectively in MCF-7 breast cancer cells we investigated whether costunolide activates extrinsic apoptotic pathway. We examined the expression levels of death receptor signaling-related proteins, caspase-3, and PARP. The results showed that procaspase-3 was cleaved to yield 17 and 20kDa fragments and activation of PARP in treated cells with 25 and 50μM of costunolide. Costunolide induce apoptosis through intrinsic mitochondria pathway in MCF-7 breast cancer Cells. We examined the expression levels of mitochondrial apoptotic pathway related proteins such as anti-apoptotic protein, B-cell lymphoma protein-2 (Bcl2), and pro-apoptotic protein Bax. Costunolide involved in the down regulation of Bcl-2 and up regulation of Bax. These results suggest that costunolide may have beneficial effects for the reduction of breast cancer growth, and new therapeutic strategy for the treatment of human cancers.

Investigaciones sobre la detección, difusión natural y control del enrollamiento clorótico del albaricoquero

Se ha aplicado la técnica de la tinción con el fluorocromo DAPI (4'-6- diamidino- 2-fenilindol) a la detección de organismos del tipo micoplasma («mycoplasma-like organisms» o MLOs) y al seguimiento, a lo largo de un año, de la distribución de MLOs en albaricoqueros enfermos de enrollamiento clorótico («apricot chloroiic leaf roll» o ACLR). Los resultados obtenidos confirman la poca fiabilidad de esta técnica para la detección precoz de micoplasmosis en árboles frutales, a causa de la baja concentración e irregular distribución de MLOs dentro de los árboles enfermos. Én cambio, la tinción con DAPI es útil para la observación a lo largo del año de la distribución de MLOs en diferentes partes de los árboles infectados por ACLR. A lo largo del invierno y la primavera, los MLOs fueron detectados solamente en las raíces y en los ramos formados el año anterior. La presencia de MLOs en los nuevos brotes no pudo ser detectada hasta el principio del verano. En trabajos previos se observaron grandes variaciones en la difusión natural del ACLR, incluso entre áreas próximas de la misma provincia de Valencia. Las investigaciones efectuadas ahora sobre las poblaciones de cicadélidos han mostrado que tanto el número de especies como el de individuos capturados son superiores en un área con una importante difusión natural del ACLR que en otra zona donde la difusión de la enfermedad es prácticamente nula. Las diferencias entre los cicadélidos capturados en estas dos áreas han proporcionado indicaciones acerca de las especies que tienen más probabilidades de ser vectores del ACLR. Se ha estudiado también, durante tres años, la influencia de tratamientos insecticidas y herbicidas sobre la difusión natural del ACLR en una plantación de albaricoqueros. En la mitad de la plantación que se dejó sin tratar, el número de cicadélidos capturados, así como el de nuevos árboles con síntomas de ACLR fue mayor que en la parte de la plantación que había sido tratada.

UTILIZAÇÃO DO COMPÓSITO NANOESTRUTURADO SIO2/TIO2NA FOTODEGRADAÇÃO DE CORANTES TÊXTEIS COM LUZ SOLAR NATURAL

SiO2/TiO2 nanostructured composites with three different ratios of Si:Ti were prepared using the sol-gel method. These materials were characterized using energy dispersive X-ray fluorescence, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence, Raman with Fourier transform infrared spectroscopy, and the specific surface area. The band gaps of materials were determined by diffuse reflectance spectra, and the values of 3.20 ± 0.01, 2.92 ± 0.02, and 2.85 ± 0.01 eV were obtained as a result of the proportional increases in the amount of Ti within the composite. The materials exhibit only the anatase (TiO2) crystalline phase and have crystalline domains ranging from 4 to 5 nm. The photodegradation process of methylene blue, royal blue GRL, and golden yellow GL dyes were studied with respect to their contact times, pH variations within the solution, and the variations in the dye concentration of the solution in response to only sunlight. The maximum amount of time for the mineralization of dyes was 90 min. The kinetics of the process follows an apparently first order model, in which the obtained rate constant values were 5.72 × 10-2 min-1 for methylene blue, 6.44 × 10-2min-1 for royal blue GRL, and 1.07 × 10-1min-1 for golden yellow.

Marine bacterial prodigiosin as dye for rubber latex, polymethyl methacrylate sheets and paper

Prodigiosin is known for its immunomodulatory, antibacterial, antimycotic, antimalarial, algicidal and anticancer activities. Here, we reported the evaluation of prodigiosin pigment as a dyeing agent in rubber latex, paper and polymethyl methacrylate (PMMA) so that it can be considered as an alternative to synthetic pigments. Maximum color shade was obtained in rubber sheet prepared with 0.5 parts per hundred gram of rubber (phr) pigment and PMMA sheet incorporated with 0.08 μg pigment. Results indicate scope for utilization of prodigiosin as dye for PMMA and rubber and also prodigiosin dyed paper as a pH indicator. Further, being a natural and water insoluble pigment, it is ecofriendly

Caracterização e aplicação de vermicultura natural e quimicamente modificada na adsorção de azul de metileno

Chemical modification of clays has been extremely studied in the search for improvements of their properties for use in various areas, such as in combating pollution by industrial effluents and dyes. In this work, the vermiculite was chemically modified in two ways, characterized and evaluated the adsorption of methylene blue dye. First was changed with the addition of a surfactant (hexadecyltrimethylammonium bromide, BHTA) making it an organophilic clay and then by adding an acid (HCl) by acid activation. Some analyzes were performed as X-ray fluorescence (FRX), X-ray diffraction (DRX), adsorption isotherms of methylene blue dye, infrared (FTIR) , scanning electron microscopy (SEM), thermal gravimetric analysis and spectroscopy energy dispersive (EDS). Analysis by FRX of natural vermiculite indicates that addition of silicon and aluminum, clay presents in its structure the magnesium, calcium and potassium with 16 % organic matter cations. The DRX analyzes indicated that the organic vermiculite was an insertion of the surfactant in the space between the lamellae, vermiculite and acid partial destruction of the structure with loss of crystallinity. The adsorption isotherms of methylene blue showed that there was a significant improvement in the removal of dye to the vermiculite with the addition of cationic surfactant hexadecyltrimethylammonium bromide and treatment with acid using HCl 2 mol/L. In acid vermiculites subsequently treated with surfactant, the adsorption capacity increased with respect to natural vermiculite, however was much lower compared vermiculite modified with acid and surfactant separately. Only the acidic vermiculite treated with surfactant adjusted to the Langmuir model. As in the infrared spectrometry proved the characteristics of natural vermiculite. In the organic vermiculite was observed the appearance of characteristic bands of CH3, CH2, and (CH3)4N. Already on acid vermiculite, it was realized a partial destruction with decreasing intensity of the characteristic band of vermiculite that is between 1074 and 952 cm-1. In the SEM analysis, it was observed that there was partial destruction to the acid treatment and a cluster is noted between the blades caused by the presence of the surfactant. The TG shows that the higher mass loss occurs at the beginning of the heating caused by the elimination of water absorbed on the surface between layers. In the organic vermiculite also observed a loss of mass between 150 and 300 °C caused decomposition of the alkylammonium molecules (surfactants)

Analysis of Acid Alizarin Violet N Dye Removal Using Sugarcane Bagasse as Adsorbent

With the development of the textile industry, there has been a demand for dye removal from contaminated effluents. In recent years, attention has been directed toward various natural solid materials that are capable of removing pollutants from contaminated water at low cost. One such material is sugarcane bagasse. The aim of the present study was to evaluate adsorption of the dye Acid Violet Alizarin N with different concentrations of sugarcane bagasse and granulometry in agitated systems at different pH. The most promising data (achieved with pH 2.5) was analyzed with both Freundlich and Langmuir isotherms equations. The model that better fits dye adsorption interaction into sugarcane bagasse is Freundlich equation, and thus the multilayer model. Moreover, a smaller bagasse granulometry led to greater dye adsorption. The best treatment was achieved with a granulometry value lower than 0.21 mm at pH 2.50, in which the total removal was estimated at a concentration of 16.25 mg mL(-1). Hence, sugarcane bagasse proves to be very attractive for dye removal from textile effluents.

Acid Black 48 dye biosorption using Saccharomyces cerevisiae immobilized with treated sugarcane bagasse

The textile industry consumes large quantities of water and chemicals, especially in dyeing and finishing processes. Textile dye adsorption can be accomplished with natural or synthetic compounds. Cell immobilization using biomaterials allows the reduction of toxicity and mechanical resistance and opens spaces within the matrix for cell growth. The use of natural materials, such as sugarcane bagasse, is promising due to the low costs involved. The aim of the present study was to evaluate the use of sugarcane bagasse treated with either polyethyleneimine (PEI), NaOH or distilled water in the cell immobilization of Saccharomyces cerevisiae for textile dye removal. Three different adsorption tests were conducted: treated sugarcane bagasse alone, free yeast cells and bagasse-immobilized yeast cells. Yeast immobilization was 31.34% with PEI-treated bagasse, 8.56% with distilled water and 22.54% with NaOH. PEI-treated bagasse exhibited the best removal rates of the dye at all pH values studied (2.50, 4.50 and 6.50). The best Acid Black 48 adsorption rates were obtained with use of free yeast cells. At pH 2.50, 1 mg of free yeast cells was able to remove 5488.49 g of the dye. The lowest adsorption capacity rates were obtained using treated bagasse alone. However, the use of bagasse-immobilized cells increased adsorption efficiency from 20 to 40%. The use of immobilized cells in textile dye removal is very attractive due to adsorbed dye precipitation, which eliminates the industrial need for centrifugation processes. Dye adsorption using only yeast cells or sugarcane bagasse requires separation methods.

Study on the mutagenicity and antimutagenicity of a natural food colour (annatto) in mouse bone marrow cells

Most manufactured foods contain chemicals added as a deliberate part of the manufacturing process. The aims of the present study were to evaluate the mutagenicity and antimutagenicity of annatto, a natural pigment extracted from the Bixa orellana L. and widely used as a colorant in foods. The micronucleus test was performed in bone marrow cells from Swiss male mice treated with one of the three concentrations of annatto (1330, 5330 and 10,670 ppm), incorporated into the diet. The animals were fed with the diets for 7 days and sacrificed 24 h after the last treatment. For the evaluation of the antimutagenic potential of annatto, at day 7, the animals received an intraperitoneal injection of cyclophosphamide (50 mg/kg body weight). Under the concentrations tested annatto did not present mutagenic or antimutagenic activities on the mice bone marrow cells. However, an increased frequency of micronucleated cells was observed when the highest concentration (10,670 ppm) was administered simultaneously with cyclophosphamide. In conclusion, the data indicate that annatto colour, for the conditions used, is neither mutagenic nor an inhibitor of induced mutations, although it should be used carefully since high doses may increase the effect of a mutagen. © 2003 Elsevier Science Ltd. All rights reserved.

Determination of the phthalocyanine textile dye, reactive turquoise blue, by electrochemical techniques

Turquoise blue 15 (AT15) is a reactive dye widely used in the textile industry to color natural fibers. The presence of these dyes in effluent and industrial wastewater is of considerable interest due ecotoxicological and environmental problems. The electrochemical reduction of this dye has been investigated in aqueous solution using cyclic voltammetry, controlled potential electrolysis and cathodic stripping voltammetry. Optimum conditions for dye discoloration by controlled potential electrolysis use an alkaline medium. Using cathodic stripping voltammetry a linear calibration graph was obtained from 5.00×10-8 mol L-1 to 1.00×10 -6 mol L-1 of AT15 at pH 4.0, using accumulation times of 180 and 240 s and an accumulation potential of 0.0 V. The proposed method was applied in direct determination of the dye in tap water and in textile industry effluent.

Acid dye biodegradation using saccharomyces cerevisiae immobilized with polyethyleneimine-treated sugarcane bagasse

Chemical reagents used by the textile industry are very diverse in their composition, ranging from inorganic compounds to polymeric compounds. Strong color is the most notable characteristic of textile effluents, and a large number of processes have been employed for color removal. In recent years, attention has been directed toward various natural solid materials that are able to remove pollutants from contaminated water at low cost, such as sugarcane bagasse. Cell immobilization has emerged as an alternative that offers many advantages in the biodegradation process, including the reuse of immobilized cells and high mechanical strength, which enables metabolic processes to occur under adverse conditions of pH, sterility, and agitation. Support treatment also increases the number of charges on the surface, thereby facilitating cell immobilization processes through adsorption and ionic bonds. Polyethyleneimine (PEI) is a polycationic compound known to have a positive effect on enzyme activity and stability. The aim of the present study was to investigate a low-cost alternative for the biodegradation and bioremediation of textile dyes, analyzing Saccharomyces cerevisiae immobilization in activated bagasse for the promotion of Acid Black 48 dye biodegradation in an aqueous solution. A 1 % concentration of a S. cerevisiae suspension was evaluated to determine cell immobilization rates. Once immobilization was established, biodegradation assays with free and immobilized yeast in PEI-treated sugarcane bagasse were evaluated for 240 h using UV-vis spectrophotometry. The analysis revealed significant relative absorbance values, indicating the occurrence of biodegradation in both treatments. Therefore, S. cerevisiae immobilized in sugarcane bagasse is very attractive for use in biodegradation processes for the treatment of textile effluents. © 2012 Springer Science+Business Media Dordrecht.