Constantly we have to deal with an exponential increase in the amount of different chemical compounds that industries synthesize and manufacture, such as drugs, pesticides, persistent organic pollutants, preservatives, and personal hygiene products. Many of these chemical substances are biologically active and interact with biomolecules, such as proteins, through specific mechanisms that lead to different biological responses. Due to the inherent risk of many compounds to the environment and to humans, their toxicological activities must be evaluated. In order to evaluate the biological activity of molecules, three types of experiments can be used: in vivo (e.g., animal tests); in vitro (e.g., cell tissue culture); and in silico simulations. In vivo and in vitro experiments are time-consuming and expensive processes, in addition to causing ethical discussions and debates. An alternative to avoid these setbacks is the use of in silico models. The scientific community thus begins to use in silico models as a possible alternative, developing a large number of models and strategies capable of predicting the toxicological properties of several chemical compounds. This review discusses methods that employ in silico models to assess and predict the possible effects of contaminants found in natural waters. manufacture drugs pesticides pollutants preservatives products biomolecules proteins responses humans evaluated molecules used e.g., eg e g (e.g. tests tests) culture culture) simulations timeconsuming time consuming processes debates waters e.g. (e.g e.g

The aim of this study was to determine the influence of the crop production system and storage period on weight loss, total phenolic content, total anthocyanin content, ascorbic acid (vitamin C) content, and antioxidant activity in strawberries, as well as their correlations. For this experiment, strawberry fruits of 'Camarosa' and 'Camino Real' at commercial maturity from both organic and conventional crop production systems located in Pelotas, Brazil, were used. The fruits were cold stored for 0, 2, 5, and 8 days at 1ºC and 90-95% RH. In general the total phenolic, total anthocyanin levels and antioxidant activity increased during cold storage. Ascorbic acid levels and fresh weight decreased significantly. Total phenol and anthocyanin levels showed positive correlations with total antioxidant activity, while the ascorbic acid content showed a negative correlation. Strawberries produced by the organic system and cold stored for five days showed higher values of antioxidant activity. After storage at 1ºC for eight days, strawberry fruits from the organic production system presented lesser anthocyanin and ascorbic acid degradation than the fruits from the conventional production system.

El objetivo de este trabajo fue determinar la influencia del sistema de producción y del período de almacenamiento de frutillas sobre la pérdida de masa, compuestos fenólicos totales, antocianinas totales, ácido ascórbico (vitamina C), actividad antioxidante y sus correlaciones. En este experimento fueron utilizadas frutillas 'Camarosa' y 'Camino Real' con madurez comercial, procedentes de cultivos en sistemas de producción orgánico y convencional, localizados en el municipio de Pelotas-RS. Los frutos fueron almacenados durante 0, 2, 5 y 8 días a 1ºC y 90-95% de HR. En general, el contenido de fenoles totales, de antocianinas totales y la actividad antioxidante aumentaron durante el almacenamiento refrigerado, mientras que los contenidos de ácido ascórbico y de masa fresca disminuyeron significativamente. Los contenidos de fenoles totales y de antocianinas totales presentaron correlación positiva con la actividad antioxidante, siendo la correlación con el contenido de ácido ascórbico negativa. Las frutillas producidas en sistema orgánico y conservadas durante cinco días, mostraron mayores valores de actividad antioxidante. Después de ocho días de almacenamiento a 1ºC, los frutos del sistema de producción orgánico presentaron menor degradación de antocianinas y de ácido ascórbico que los frutos del sistema de producción convencional.

Durante o armazenamento, pode ocorrer a perda de compostos voláteis responsáveis pelo aroma e o aumento de compostos indesejáveis, o que ocasiona a perda de qualidade do morango, reduzindo a vida de prateleira e levando à rejeição do produto pelos consumidores. Neste trabalho, foi avaliada a influência do sistema de produção (convencional e orgânico) e do período de armazenamento (0, 2, 5, 8 dias) nas características físicas e químicas (CFQ) e nos compostos voláteis (CV) de morango das cultivares 'Camarosa' e 'Camino Real', utilizando morangos de pomar comercial da região de Pelotas/RS. Os frutos foram colhidos em estádio de maturação comercial e com boa aparência. O planejamento experimental foi casualizado, em triplicata de 15 frutos. Os morangos foram armazenados a T de 1°C, com 90-95% umidade relativa (UR). Foram avaliadas a perda de massa, a coloração instrumental [L*, a*, b* e ângulo hue (H)] , a firmeza, os sólidos solúveis (SS), a acidez titulável (AT), a relação SS/AT, pH e os teores de CV. Os resultados foram submetidos à análise de variância e as diferenças significativas determinadas pelo teste de Tukey (P<0,05). Os resultados revelaram que pH, SS, relação SS/AT, podridões e perda de massa aumentaram durante o armazenamento. A firmeza se manteve irregular e a AT e H diminuíram significativamente. Os teores de CV aumentaram com exceção do acetato de metila (AM). O etanol (Et), o acetaldeído (AA) e o acetato de etila (AE) correlacionaram-se positivamente com o teor de podridões para a cultivar 'Camino Real' do cultivo orgânico. De modo geral o AM correlacionou-se inversamente com o teor de podridões, exceto para a cultivar 'Camino Real' do cultivo convencional. Os morangos de ambas as cultivares podem ser armazenados por cinco dias com qualidade, independente do sistema de produção.

During the storage a loss of volatile compounds responsible for the aroma and an increase of undesirable compounds can occur leading to a decrease in the strawberry quality, a reduction of the shelf life and product rejection by the consumers. In the present work the influence of the planting system (conventional and organic) and the storage period (0, 2, 5 and 8 days) upon physical and chemical characteristics (FCC) as well as on strawberry volatile compounds (VC) in the cultivars 'Camarosa' and 'Camino Real' were evaluated using strawberries from a commercial orchard from Pelotas/RS. The fruits were harvested in a stage of commercial maturation and sound appearance. The experimental planning was randomized, in triplicate of fifteen fruits. The strawberries were stored at 1°C and 90-95% of relative humidity (RH). The mass loss, the instrumental color [L*, a*, b* and hue angle (H)], the firmness, the soluble solids (SS), the titratable acidity (TA), the SS/TA ratio, the pH and VC content were determined. The results were analyzed by analysis of variance and significant differences were determined using Tukey's test (P<0.05). The results show that pH, SS, relation SS/TA, decay and mass loss have increased during storage. The firmness varied irregularly and TA and H decreased significantly. The values of VC increased with the exception of methyl acetate (MA). Ethanol (Et), acetaldehyde (AA) and ethyl acetate (EA) correlated positively with decay for organic cultivated 'Camino Real'. In a general way, the MA correlated inversely with decay with the exception of conventional cultivated 'Camino Real'. Strawberries from both cultures can be stored for five days without loosing quality regardless the production system.

O arroz é classificado como uma planta tolerante ao amônio (NH4+) devido à predominância desse íon nos solos alagados. Entretanto, nas regiões oxidadas do solo e da rizosfera do arroz pode haver a formação de nitrato (NO3-) e esta se tornar importante fonte de N para cultura. Este trabalho foi conduzido com o objetivo de avaliar o efeito de diferentes proporções entre os íons NH4+ e NO3- no desenvolvimento do arroz em solução nutritiva. O experimento foi realizado em casa de vegetação no período de janeiro a fevereiro de 2008, em solução nutritiva com as seguintes proporções entre NH4+ e NO3-: 100:0, 75:25, 50:50, 25:75 e 0:100 na concentração de 5,0 mmol L-1 de N. Foi cultivado o genótipo IRGA 417 e avaliado o rendimento de biomassa, os teores de N, K, Ca e Mg na biomassa e na seiva do xilema. Houve toxidez por NH4+ nas proporções de 100:0 e 75:25 e por NO3- nas proporções de 25:75 e 0:100. Na proporção de 50:50 as plantas se desenvolveram normalmente. O suprimento combinado de NH4+ e NO3- aumentou a produção de biomassa em relação ao NH4+ e ao NO3- supridos isoladamente. O NH 4+ na solução reduziu os teores de Ca e Mg na biomassa, porém não influenciou o teor de N e o de K. Já na seiva do xilema houve redução nos teores de K, Ca e Mg, indicando que o NH4+ influenciou na absorção desses cátions. A quantidade total absorvida de N, K, Mg e Ca foi maior com o suprimento combinado de NH4+ e NO3-, indicando que, além de promover melhor desenvolvimento das plantas de arroz, aumenta a eficiência de absorção de nutrientes em relação ao suprimento isolado das duas formas de N.

Rice is classified as an ammonium (NH4+)- tolerant plant due the predominance of this ion in flooded soils. However, in the oxygenated zones of flooded soil and in the rice rhizosphere, nitrate (NO3-) can be formed and become an important nitrogen (N) source for the crop. This experiment was carried out to evaluate the effect of different ammonium:nitrate proportions on rice development in nutrient solution. The experiment was carried out in a greenhouse, from January until February 2008 in a nutrient solution with the following NH4+: NO3- proportions: 100:0, 75:25; 50:50; 25:75 and 0:100, at 5.0 mmol L-1 N. The genotype IRGA 417 was used and the biomass production, the nitrogen, calcium, magnesium and potassium contents in tissue and xylem sap were evaluated. The presence of ammonium at the proportions 100:0 and 75:25 resulted in plant toxicity, as well as for nitrate at the proportions 25:75 and 0:100. The combined supply of ammonium and nitrate increased biomass production in relation to solely NH4+ or NO3- supply. Ammonium in solution affected negatively Ca and Mg, whereas no effect was observed on N or K tissue contents. However, in the xylem sap, both K, Ca and Mg contents were affected by ammonium. The higher total absorbed quantities of N, K, Ca, and Mg and better rice development indicated that the combined supply results in higher nutrient absorption efficiency than solely ammonium or nitrate supply.

This paper evaluates the adsorption capacity of zirconocene-based silica materials in the pre-concentration of antimicrobians (tetracycline, sulfamethoxazole and trimethoprim) in aqueous medium. These materials were prepared by grafting the zirconocene onto silicas pre-treated at different temperatures. The retention capacity of these materials was evaluated by off line SPE and HPLC-UV and the proposed methodology was validated in ultrapure, tap and river water. The recovery for tetracycline was 72% (in the solid phase A) and, for sulfamethoxazole and trimethoprim was 68 and 95% in the commercial C18, respectively. The target antimicrobians were not detected in the Arroio Dilúvio (Porto Alegre - RS).