Uso de estruturas flutuantes realocáveis para o cultivo de ostras em áreas sujeitas a grandes variações de salinidade.

ODS 14: Vida na água

Recomendações para o uso de coletores artificiais, para a captação, o manejo e o transporte de sementes de ostras nativas do gênero crassostrea em ambientes estuarinos da Costa Brasileira.

ODS 2, ODS 14

“Polarographic behaviour of a metabolite from ampicillin 2 — hydroxy-3-phenyl-6-methylpyrazine”.

Le 2-hydroxi-3-phenyl-6-méthylpyrazine est un produit de dégradation acide de l’ampicilline.On étudie la réduction polarographique de l’2-hydroxi-3-phenyl-6-methylpyrazine dans un acide dilué.Dans un milieu fortement acide, la réduction se produit par une onde irréversible à deux électrons, trois protons qui correspondent à la réduction du groupe — C = N —.La réaction se fait au moyen d’une diffusion controlée avec un coefficient de température de 1.83 °C—1 et une énergie d’activation de 3.51 kcal mol—1

A.C. polarographic study of the interaction between thiol compounds and cephradoxil

The interaction of glutathione and cysteine with the Cephalosporin Cephradoxil was investigated by a.c. polarography. From measurements of the peak potential at different antibiotic concentrations, the following interaction constants at physiological conditions were calculated : GSH-Cephradoxil = 5.71 x 104 M-1; Cys-Cephradoxil = 1.92 x 103 M-1. The interaction processes were spontaneous for both thiol compounds with an important entropic contribution to the free energy. Linear correlations for the in vivo first order elimination constants and the in vitro affinity constant of three cephalosporins are also reported

Hydrogen-bonded supramolecular structures of three related 4-(5-nitro-2-furyl)-1,4-dihydropyridines

In ethyl 5-cyano-2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3-carboxylate, C15H15N3O5, the molecules are linked into chains by a single N-H (...) O hydrogen bond. The molecules in diethyl 2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3,5-dicarboxylate, C17H20N2O7, are linked by a combination of one N-H (...) O hydrogen bond and two CH (...) O hydrogen bonds into sheets built from equal numbers of R-2(2)(17) and R-4(4)(18) rings. In 2,6-dimethyl-4-(5-nitro-2-furyl)1,4-dihydropyridine-3,5-dicarbonitrile, C13H10N4O3, the molecules are linked by a combination of a three-centre NH (...) (O)(2) hydrogen bond and two independent two-centre C-H (...) O hydrogen bonds into complex sheets containing four types of ring.</p

Hydrogen-bonded supramolecular structures of three related 4-(5-nitro-2-furyl)-1,4-dihydropyridines

In ethyl 5-cyano-2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3-carboxylate, C15H15N3O5, the molecules are linked into chains by a single N-H (...) O hydrogen bond. The molecules in diethyl 2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3,5-dicarboxylate, C17H20N2O7, are linked by a combination of one N-H (...) O hydrogen bond and two CH (...) O hydrogen bonds into sheets built from equal numbers of R-2(2)(17) and R-4(4)(18) rings. In 2,6-dimethyl-4-(5-nitro-2-furyl)1,4-dihydropyridine-3,5-dicarbonitrile, C13H10N4O3, the molecules are linked by a combination of a three-centre NH (...) (O)(2) hydrogen bond and two independent two-centre C-H (...) O hydrogen bonds into complex sheets containing four types of ring