1,721,178 research outputs found
Ranking and classification of non-ionic organic pesticides for environmental distribution: A QSAR approach
No full textRanking of aquatic toxicity of esters modelled by QSAR
No full textAlternative methods like predictions based on Quantitative Structure–Activity Relationships (QSARs) are now accepted to fill data gaps and define priority lists for more expensive and time consuming assessments. A heterogeneous data set of 74 esters was studied for their aquatic toxicity, and available experimental toxicity data on algae, Daphnia
and fish were used to develop statistically validated QSAR models, obtained using multiple linear regression (MLR) by the OLS (Ordinary Least Squares) method and GA-VSS (Variable Subset Selection by Genetic Algorithms) to predict missing values. An ESter Aquatic Toxicity INdex (ESATIN) was then obtained by combining, by PCA, experimental and predicted toxicity data, from which model outliers and esters highly influential due to their structure had been eliminated.
Finally this integrated aquatic toxicity index, defined by the PC1 score, was modelled using only a few theoretical molecular descriptors. This last QSAR model, statistically validated for its predictive power, could be proposed as a preliminary evaluative method for screening/prioritising esters according to their integrated aquatic toxicity, just starting from their molecular structure
Changes in the interaction between CNS cholinergic and dopaminergic neurons induced by L-alpha-glycerylphosphorylcholine, a cholinomimetic drug.
No full textAGE-RELATED ALTERATION OF PKC, A KEY ENZYME IN MEMORY PROCESSES: PHYSIOLOGICAL AND PATHOLOGICAL EXAMPLES
No full textBrain aging is characterized by a progressive decline of the cognitive and memory functions. It is becoming increasingly clear that protein phosphorylation and, in particular, the activity of the calcium-phospholipid-dependent protein kinase C (PKC) may be one of the fundamental cellular changes associated with memory function. PKC is a multigene family of enzymes highly expressed in brain tissues. The activation of kinase C is coupled with its translocation from the cytosol to different intracellular sites and recent studies have demonstrated the key role played by several anchoring proteins in this mechanism. PKC-phosphorylating activity appears to be impaired during senescence at brain level in a strain-dependent fashion in rodents. Whereas the levels of the various isoforms do not show age-related alterations, the enzyme translocation upon phorbol-ester treatment is deficitary among all strains investigated. Anchoring proteins may contribute to this activation deficit. We discuss also modifications of the PKC system in Alzheimer's disease that may be related to pathological alterations in neurotransmission. A better insight of the different factors controlling brain-PKC activation may be important not only for elucidating the molecular basis of neuronal transmission, but also for identifying new approaches for correcting or even preventing age-dependent changes in brain function
Distribuzione di metalli pesanti in suoli e muschi di Piemonte e Sicilia: analisi mediante metodi chemiometrici
No full textModellamento QSAR per la predizione di proprietà chimico-fisiche ed ecotossicologiche di esteri
No full text
- …
