No abstract

This study evaluated a modified nanostructured release system employing diclofenac as a drug model. Biodegradable chitosan nanoparticles were prepared with chitosan concentrations between 0.5 and 0.8% (w/v) by template polymerization method using methacrylic acid in aqueous solution. Chitosanpoly(methacrylic acid) (CS-PMAA) nanoparticles showed uniform size around 50-100 nm, homogeneous morphology, and spherical shape. Raw material and chitosan nanoparticles were characterized by thermal analysis, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM), confirming the interaction between chitosan and methacrylic acid during nanoparticles preparation. Diclofenac sorption on the chitosan nanoparticles surface was achieved by incubation in water/ethanol (1:1) drug solution in concentrations of 0.5 and 0.8 mg/mL. The diclofenac amount sorbed per gram of CS-PMAA nanoparticles, when in a 0.5 mg/mL sodium diclofenac solution, was as follows: 12.93, 15, 20.87, and 29.63 mg/g for CS-PMAA nanoparticles 0.5, 0.6, 0.7, and 0.8% (w/v), respectively. When a 0.8 mg/mL sodium diclofenac solution was used, higher sorption efficiencies were obtained: For CS-PMAA nanoparticles with chitosan concentrations of 0.5, 0.6, 0.7, and 0.8% (w/v), the sorption efficiencies were 33.39, 49.58, 55.23, and 67.2 mg/g, respectively. Diclofenac sorption kinetics followed a second-order kinetics. Drug release from nanoparticles occurred in a period of up to 48 h and obeyed Korsmeyer-Peppas model, which was characterized mainly by Fickian diffusion transport.

Pode-se dizer que a sobrevivência e o desenvolvimento de Aphis craccivora Koch (Hemiptera: Aphididae) é afetado pelo tipo de planta hospedeira. Objetivou-se estimar os parâmetros demográficos do pulgão-preto (Aphis craccivora Koch) em cultivares de feijão-caupi (Vigna unguiculata (L.) Walp.) recomendadas para a colheita mecanizada no Brasil. Foram usadas as cultivares: BRS Pingo de Ouro, BRS Tumucumaque, BRS Itaim, BRS Nova Era, BRS Imponente e BRS Guariba. A cultivar VITA 7 fez parte do estudo na qualidade de padrão de susceptibilidade ao inseto. Foi formado uma coorte, onde cada cultivar teve 10 plantas como réplicas, e cada réplica recebeu um pulgão. Foram registrados diariamente o número de indivíduos vivos, o número de descendentes, os quais em seguida eram retirados e a longevidade dos insetos da coorte. A razão finita de crescimento (λ) do pulgão-preto nas cultivares BRS Nova Era, BRS Imponente, BRS Tumucumaque, VITA 7, BRS Itaim, BRS Pingo de Ouro e BRS Guariba foi, respectivamente, de 1,77, 1,74, 1,73, 1,73, 1,73, 1,71 e 1,16. Os dados sugerem que a cultivar BRS Guariba apresenta resistência do tipo antibiose frente ao pulgão-preto, e que possivelmente sua população não deve estar sujeita a surtos.

The objective of this work was to evaluate the resistance of advanced semi-erect cowpea (Vigna unguiculata) lines, by means of a screening assay for resistance and the elaboration of fertility-life tables of Aphis craccivora (Hemiptera: Aphididae). The experiments were carried out in a screenhouse. For the resistance trial, 15 advanced cowpea lines were used, as well as two standard genotypes for resistance and two for susceptibility, which were arranged in six blocks. After resistance was determined, two lines with the highest and lowest resistance were selected for the development of the fertility-life tables which were used to estimate demographic parameters. The MNCO4-762F-03 and MNCO4-762F-09 cowpea lines were classified as resistant, for which cowpea aphids showed the lowest values (in parentheses, respectively) for: net reproductive rate (RO = 3.0 and 2.5), intrinsic rate of increase (rm = 0.16 and 0.15), and finite rate of increase (λ = 1.18 and 1.16). The highest values were obtained for the 'Vita-7', MNCO4-795F-168, and 'BRS Tumucumaque' genotypes. The MNCO4-762F-03 and MNCO4-762F-09 lines show antibiosis-type resistance, which directly affects the reproductive potential of the cowpea aphid population.

Fonte referencial de informaà §Ã£o para a Pesquisa Apoiada pela FAPESP (Referência obtida automaticamente do Web of Science, por meio da informaà §Ã£o sobre o financiamento pela FAPESP e o número do processo correspondente, incluÃda na publicaà §Ã£o pelos autores.