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In this work, a recyclable and sensitive fluorescent nanoprobe, RhoB@ZIF-8 composite, has been designed and successfully synthesized by encapsulating rhodamine B (abbreviated as RhoB) into the cavities of zeolitic imidazolate framework-8 (ZIF-8) metal-organic frameworks (MOFs) through a facile one-pot method under mild conditions. The RhoB@ZIF-8 composite exhibited an emission band at 589 nm with fluorescent quantum yield of 19.8%. Since there was an efficient overlap between the absorption of malachite green (MG) and the fluorescence spectra (excitation and emission bands) of RhoB@ZIF-8 composite, the fluorescence intensity decreased sharply after MG was added. The fluorescence quenching was linear with the concentration of MG in the range of 0 to 13.0 μM with a low limit of detection (LOD) of 0.089 μM. Remarkably, this proposed sensing system has good performances including high specificity, good stability and recyclability. Finally, this fluorescent probe was successfully applied to the detection of MG in aquaculture water and fish tissue samples, revealing its potential practicability. This work will provide us a new research platform for MG sensing.

Seeds used to plant wheat, corn and rice crops in Brazil are treated with the insecticide carbofuran associated with the dye rhodamine B, attracting granivorous birds and causing mortality during sowing. The objective of this study was to evaluate if using camouflaged seeds can minimize mortality caused by the ingestion of seeds with carbofuran. Alternatives for reducing mortality, such as using carbofuran without rhodamine B or replacing carbofuran by carbosulfan, were compared. Three experiments were carried out in regions of known bird mortality in the states of Paraná and São Paulo, Brazil, using conventional sowing over plowed soil in the traditional planting system, 15,896 kg of seeds in 111.46 ha. Bird carcasses were collected and dissected to unveil which poisoned seed treatments had caused birds' deaths. The mortality mounted to 296 birds of 11 species. Eared doves were the most numerous casualties (263). There was significant correlation between mortality and number of consumed seeds. The consumption of camouflaged seeds was lower than that of commercial seeds treated with rhodamine B. The mortality caused by seeds with both rhodamine B and carbofuran was higher than mortality caused by seeds camouflaged only with carbofuran. The replacement of carbofuran with carbosulfan also seemingly reduced mortality, but carbosulfan mortality might have been underestimated as a result of the apparent movement of affected birds after exposure. Seeds treated with carbofuran and rhodamine B and without any dye, were attractive. Because legal requirement for seeds treated with pesticides to be differentiated by dying, the substitution of rhodamine B by camouflaging must be encouraged.Plantações de trigo, milho e arroz no Brasil utilizam sementes tratadas com o inseticida carbofuran, associado ao corante rodamina B, que é atrativo às aves granívoras, causando notável mortalidade durante o plantio. O objetivo deste estudo foi avaliar se sementes camufladas minimizam a mortalidade de aves, causada pela ingestão de sementes tratadas com carbofuran. Possíveis alternativas para redução da mortalidade como carbofuran sem a rodamina B e o carbusulfan, foram testadas comparativamente. Realizaram-se três experimentos em regiões de expressiva mortalidade de aves no Paraná e São Paulo. Semeaduras foram convencionais sobre solo arado no sistema de plantio tradicional, utilizando 15.896 kg de sementes em 111,46 ha. Carcaças de aves foram coletadas e dissecadas, revelando quais tratamentos de sementes envenenadas causaram mortes. A mortalidade foi de 296 aves de 11 espécies. Pombas avoantes foram as vitimas mais numerosas com 263 mortes. Houve correlação significativa entre mortalidade e quantidade de sementes consumidas. O consumo de sementes camufladas e com carbofuran foi menor em relação ao de sementes com rodamina B e com carbosulfan. A mortalidade causada por sementes com rodamina B e carbofuran foi maior em relação à causada por sementes camufladas e com carbofuran, que foi igual à causada por sementes com rodamina B e carbosulfan, cujo inventário foi subestimado. Sementes tratadas com carbofuran, com e sem rodamina B, foram atrativas. Como sementes tratadas com agrotóxicos devem por lei receber coloração diferenciada para evitar acidentes com humanos, camuflagem de sementes deve ser encorajada substituindo a rodamina B.

Wheat, corn and rice crops in Brazil use seeds treated with systemic insecticide/nematicide carbofuran, mixed to rhodamine B red dye. Carbofuran is toxic and rhodamine B is attractive to wild birds that eat up these seeds, resulting in notable mortality during planting. A field experiment was performed in southeast Brazil to evaluate if camouflaged seeds would be less consumed by wild birds in comparison to commercial seeds with red-colored rhodamine B and aposematic blue seeds. Camouflaged seeds were less removed than seeds with rhodamine B and natural colors. The camouflaging was more effective in the presence of irregularities and litter. There was no removal of blue-colored seeds. As legislation requires treated seeds to receive a different color to avoid accidents with humans, camouflaging may be used as replacement of rhodamine B to reduce mortality rates of wild birds.Plantações de trigo milho e arroz no Brasil utilizam sementes tratadas com o inseticida e nematicida sistêmico carbofuran, associado ao corante vermelho rodamina B. O carbofuran é tóxico e a rodamina B é atrativa às aves silvestres, as quais consomem estas sementes, resultando em notável mortalidade durante o plantio. Um experimento realizado em campo agrícola no sudeste do Brasil mostrou que sementes camufladas foram menos removidas por aves silvestres do que sementes com rodamina B. A camuflagem foi potencializada em presença de irregularidades e serrapilheira no solo. Não houve remoção de sementes de cor azul, mas a formulação granular de cor azul tem causado mortalidade de aves nos USA e Canadá. Como sementes tratadas com agrotóxicos devem, de acordo com a legislação, receber coloração diferenciada para evitar acidentes com humanos, a camuflagem pode ser utilizada, substituindo a rodamina B.

This paper analyzes the effect of some properties of different catalysts on the photocatalytic activity. The efficiency has been determined for two different processes: NOx abatement and self-cleaning for Rhodamine B and tobacco extract being, the TiO2 based photocatalyst, supported as coatings on white mortar. Eight different catalysts were tested, seven commercial ones and one home-made catalyst with improved visible light absorption properties. Additionally, some of them were submitted to exposition to water and/or calcinations to alter their physical properties. A kinetic approach was used to evaluate the photocatalytic activity, being the first reaction constant (for NO) and just empirical constants (for self-cleaning) the parameters used for the comparison of the different materials. As a result, the efficiency, even for ranking, is dependent on the type of contaminant used in the experiment. In general, NO oxidation and tobacco followed similar trends while no clear relations were found for Rhodamine B.

El trióxido de arsénico ha demostrado ser un inductor de apoptosis en líneas celulares de leucemia promielocítica aguda. Estudios clínicos han demostrado su efectividad en el tratamiento de esta enfermedad en pacientes refractarios al tratamiento con ácido retinoico. En este trabajo se determinó la actividad citotóxica de este producto frente a un panel de 3 líneas celulares tumorales humanas de tumores sólidos (M14, MCF7, HT-29) y una línea de leucemia promielocítica aguda, utilizando la técnica de la sulforhodamina B. Se realizaron 2 experimentos en los cuales las células fueron incubadas durante 48 h en presencia del producto. Las IC50 s obtenidas en ambos experimentos fueron: M14 (0,471 y 0,450 µg/mL), MCF7 (0,122 µg/mL), HT-29 (0,543 y 0,659 µ g/mL) y HL60 (0,487 y 0,351 µg/mL). Se concluyó que el trióxido de arsénico posee una marcada actividad citotóxica, no solo en la línea de leucemia promielocítica aguda, sino también, en las líneas de tumores sólidos humanos estudiadas por lo que se recomendó realizar un estudio de actividad antitumoral de este producto.Arsenic trioxide has proved to be an inductor of apoptosis in cellular lines of acute promyelocytic leukemia. Clinical studies have showed its effectiveness in the treatment of this disease in patients refractory to the treatment with retinoic acid. It was determined the cytotoxic activity of this product against a panel of 3 human tumoral cellular lines of solid tumors (M14, MCF7, HT-29) and a line of acute promyelocytic leukemia, using the sulforhodamine B technique. Two experiments were made in which the cells were incubated for 48 hours in the presence of the product. The IC50 s obtained in both experiments were: M14 (0.471 and 0.450 µg/mL), MCF7 (0.122 µg/mL), HT-29 (0.543 and 0.659 µg/mL) and HL60 (0.487 and 0.351 µg/mL). It was concluded that the arsenic trioxide has a marked cytotoxic activity not only in the line of acute promyelocytic leukemia, but also in the studied lines of human solid tumors. Therefore, it was recommended the conduction of a study of the antitumoral activity of this product.

A novel rhodamine-based Hg2+ chemosensor P2 containing polyether was readily synthesized and investigated, which displayed high selectivity and sensitivity for Hg2+. Because of good water-solubility of polyther, the rhodamine-based chemosensor containing polyether can be used in aqueous solution. The sensor responded rapidly to Hg2+ in pure water solutions with a 1:1 stoichiometry. Meanwhile, it indicated excellent adaptability and also the responsiveness.