INTOXICAÇÃO NATURAL DE BOVINOS LEITEIROS POR Cestrum laevigatum (SOLANACEAE) NO AGRESTE DE PERNAMBUCO – BRASIL

The aim of the present study was to report an outbreak of natural poisoning by Cestrum laevigatum in dairy cattle in the “Agreste” region of Pernambuco state, Brazil. Epidemiological and clinical data were collected. Among a lot of 60 cows, eight became ill and four died. Two cows underwent necropsy, during which fragments of the central nervous system, liver, gall bladder, spleen and kidney were collected for histopathlogical analysis. Blood samples were collected for hematological and biochemical tests. The animals exhibited apathy, muscle tremors, reduced appetite, different degrees of dehydration and compromised reticulorumen dynamics as well as a small quantity of dry feces with the presence of mucus and blood. The laboratory exams revealed an increase in serum activity of aspartate aminotransferase and gamma glutamyltransferase as well as hypoalbuminemia. The necropsy revealed an enlarged liver and cutting surface with a nutmeg aspect as well as areas of hemorrhaging in the heart, trachea, abomasum, spleen, intestine and bladder. The microscopic analysis revealed centrilobular hepatic necrosis associated to accentuated hemorrhaging. These findings characterized poisoning by Cestrum laevigatum and led to the adoption of control and prevention measures

Are Quantum Chemistry Semiempirical Methods Effective to Predict Solid State Structure and Adsorption in Metal Organic Frameworks?

Semiempirical quantum chemistry methods have been used mainly to treat organic and biological compounds with hundreds of atoms and problems involving larger systems. However, their use in the description of solids is still quite restricted. Our aim was to show that semiempirical methods can be used to study MOF (Metal–Organic Framework) systems. The present study analyzed the predictive power of AM1, PM3, PM6, and PM7 methods with respect to the calculation of up to 72 crystal structures of MOFs, and evaluated how the use of the algorithm MOZYME impacted the predictions. Our results showed that PM6 and PM7 methods yielded an accurate description of the geometric arrangement of these MOFs, also observing that MOZYME does not compromise the accuracy of these methods and, for larger systems (above 700 atoms), the computation time is reduced to about 50%. Supported by these results, we chose to evaluate whether the semiempirical methods can be applied to investigate gas adsorption, using a system theoretically and experimentally well investigated: Mg-MOF-74/CO₂. PM6 obtained a description for the geometry of host–guest interaction and adsorption enthalpy in agreement with traditional DFT, while PM7 is in agreement with experimental results and DFT estimates with the use of dispersion corrections

Theoretical spectroscopic study of the conjugate microcystin-LR-europium cryptate

In this work, theoretical tools were used to study spectroscopic properties of the conjugate microcystin-LR-europium cryptate. The Sparkle/AM1 model was applied to predict the geometry of the system and the INDO/S-CIS model was used to calculate the excited state energies. Based on the Judd-Ofelt theory, the intensity parameters were predicted and a theoretical model based on the theory of the 4f-4f transitions was applied to calculate energy transfer and backtransfer rates, radiative and non-radiative decay rates, quantum efficiency and quantum yield. A detailed study of the luminescent properties of the conjugate Microcystin-LR-europium cryptate was carried out. The results show that the theoretical quantum yield of luminescence of 23% is in good agreement with the experimental value published. This fact suggests that this theoretical protocol can be used to design new systems in order to improve their luminescence properties. The results suggest that this luminescent system may be a good conjugate for using in assay ELISA for detection by luminescence of the Microcystin-LR in water

Uma metodologia para o projeto teórico de conversores moleculares de luz A methodology for the theoretical design of light conversion molecular devices

<abstract language="eng">Recentlly, we have proposed the representation of lanthanides within AM1 as sparkles for the purpose of obtaing ground state geometries of their complexes. We tested our quantum chemical sparkle model (SMLC/AM1) for the prediction of the crystallographic structure of complexes with coordination number nine, eight and seven. A technique is introduced for the theoretical prediction of eletronic spectra of the organic part of lanthanide complexes by replacing the metal ion by a point charge with the ligands held in their positions as determined by the SMLC/AM1, and by computing the theoretical spectra via the intermediate neglect of differential overlap/spectroscopic-configuration interaction (INDO/S-CI)