38 research outputs found
Uso de estruturas flutuantes realocåveis para o cultivo de ostras em åreas sujeitas a grandes variaçÔes de salinidade.
ODS 14: Vida na ĂĄgua
RecomendaçÔes para o uso de coletores artificiais, para a captação, o manejo e o transporte de sementes de ostras nativas do gĂȘnero crassostrea em ambientes estuarinos da Costa Brasileira.
ODS 2, ODS 14
The early facilitatory effect of a peripheral spatially noninformative prime stimulus depends on target stimulus features
âPolarographic behaviour of a metabolite from ampicillin 2 â hydroxy-3-phenyl-6-methylpyrazineâ.
Le 2-hydroxi-3-phenyl-6-mĂ©thylpyrazine est un produit de dĂ©gradation acide de lâampicilline.On Ă©tudie la rĂ©duction polarographique de lâ2-hydroxi-3-phenyl-6-methylpyrazine dans un acide diluĂ©.Dans un milieu fortement acide, la rĂ©duction se produit par une onde irrĂ©versible Ă deux Ă©lectrons, trois protons qui correspondent Ă la rĂ©duction du groupe â C = N â.La rĂ©action se fait au moyen dâune diffusion controlĂ©e avec un coefficient de tempĂ©rature de 1.83 °Câ1 et une Ă©nergie dâactivation de 3.51 kcal molâ1
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
DETERMINATION OF ARSENIC (III) BY DIFFERENTIAL PULSE POLAROGRAPHY IN THE WATERS OF CAMARONES AREA, CHILE
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