RESUMEN
Food and feed safety assessment is not enhanced by performing protein expression analysis on stacked trait products. The expression levels of six proteins in cotton matrices from four single cotton events and three conventionally stacked trait cotton products are reported. Three proteins were for insect control; two proteins confer herbicide tolerance; and one protein was a transformation-selectable marker. The cotton matrices were produced at three U.S., five Brazil, and two Argentina field trials. Similar protein expression was observed for all six proteins in the stacked trait products and the single events. However, when two copies of the bar gene were present in the stacked trait products, the expression level of phosphinothricin acetyl transferase herbicide tolerance was additive. Conventional breeding of genetically engineered traits does not alter the level or pattern of expression of the newly introduced proteins, except when multiple copies of the same transgene are present.
Asunto(s)
Gossypium/genética , Proteínas de Plantas/genética , Acetiltransferasas/genética , Acetiltransferasas/metabolismo , Gossypium/efectos de los fármacos , Gossypium/metabolismo , Herbicidas/farmacología , Hibridación Genética , Proteínas de Plantas/metabolismoRESUMEN
Four new disubstituted and monosubstituted nitro- and amino- bis(pyrazol-1-yl)pyridine (bppy) ligands, substituted at the pyrazole 4-position (1, 2, 5, 6) have been synthesized, along with two luminescent Eu(iii) tris-ß-diketonate derivatives of the amino substituted ligands (7, 8). The compounds have been studied using UV-Vis absorbance spectroscopy and cyclic voltammetry which has allowed for characterization of the electronic environments of these ligands. The calculated HOMO-LUMO gap values (1: 3.54 eV; 2: 3.53 eV; 5: 3.01 eV; 6: 3.66 eV) differ from that of bppy (3.86 eV) and the range is indicative that tuning of the ligand electronic environment is possible. Additionally, fluorescence spectroscopy studies were employed to determine ligand T1 energy levels of the amine-bearing ligands 2 and 6, yielding values of T1 of 25 381 cm-1 and 26 201 cm-1, respectively. These ligands were employed in the synthesis of Eu(iii) complexes 7 and 8, for which the absolute and intrinsic quantum yields, lifetimes and ligand sensitization efficiencies were determined.
RESUMEN
Controlled covalent modification of graphene via electrochemically assisted grafting of molecules is expected to be a robust method for tuning the doping levels and work function and therefore enabling the deployment of graphene in photovoltaic and battery applications. By using aryliodonium salts, in particular, bis(4-nitrophenyl)iodonium tetrafluoroborate, the grafting density can be adjusted from 4 × 10(13) to 3 × 10(14) molecules per cm(2). New insights on the grafting mechanism and the reactivity of the graphene are reported here. Clean basal planes were found to have increased reactivity compared to atomic-level point defects (single vacancies). High resolution scanning tunnelling microscopy (STM) shows that some of the grafts present three-fold symmetry, which may indicate that the grafts are pairs of molecules. The point of attachment of the second molecule is under investigation using computational work which includes simulations of the STM images. Elongated as well as extended grafts (larger than 4 nm) are also observed.