Modeling Lanthanide Complexes: Towards the Theoretical Design of Light Conversion Molecular Devices

Theoretical techniques have been developed and/or improved to predict the molecular structure of lanthanide complexes which were used to calculate their electronic properties, in particular, their electronic spectra and energy levels necessary to calculate the rates of energy transfer from the ligands to the metal ion. The molecular structure has been obtained by the SMLC/AM1 (Sparkle Model for the Calculation of Lanthanide Complexes – Austin Model 1) model where the lanthanide ion is simulated by a sparkle implemented into the AM1 Hamiltonian used to perform a HF-SCF (Hartree-Fock Self-Consistent Field) calculation. The previous implementation of the SMLC/AM1 model (sparkle/1) involving only two parameters has been generalized to be consistent with the AM1 Hamiltonian and the new model (sparkle/2) significantly improved the prediction of molecular structures of Eu(III) complexes. For the electronic spectra and energy level calculations of the lanthanide complexes the model replaces the metal ion by a point charge with the ligands held in their positions as determined by the SMLC/AM1 model, and uses a INDO/S-CI (intermediate neglect of differential overlap/spectroscopic-configuration interaction) model. A preliminary study of the solvent effects on the absorption spectra of the free ligand is also presented. For the ligand-lanthanide ion energy transfer Fermi's golden rule is used with the multipolar and exchange mechanisms being implemented and tested for several complexes. These theoretical techniques have been applied to several complexes yielding very good results when compared to experimental data as well as predictions for the molecular and electronic structures and the relative contributions of the mechanisms for the energy transfer rates. This revised version was published online in June 2006 with corrections to the Cover Date.     

Occurrence of macro B chromosomes in Astyanax scabripinnis paranae (Pisces,Characiformes, Characidae)

B chromosomes occur in several Neotropical fish species. Cytogenetic analysis of 27 specimens (15 females and 12 males) of Astyanax scabripinnis paranae from the Araquá river (a small headwater tributary of the Tietê river) shows that this population has 2n=50 chromosomes (4M+30 SM+4ST+12A), two chromosome pairs with NORs and conspicuous C-band positive blocks in the terminal position of the long arm of four chromosome pairs. In this population, eight females presented 2n=51 chromosomes and the extra chromosome was a large metacentric similar in size and morphology to the first chromosome pair in the karotype. This accessory chromosome is entirely heterochromatic in C-banded metaphases and shows a late replication pattern evidenced by BrdU incorporation. There was no significant correlation between the presence of B chromosomes and increased NOR activity at the P>0.05 level. Some aspects related to these B chromosomes are discussed.     

The marsupial Didelphis albiventris is an improbable host of Paracoccidioides brasiliensis in an endemic area of paracoccidioidomycosis in Minas Gerais, Brazil

To determine whether Didelphis albiventris is naturally infected with Paracoccidioides brasiliensis, 20 specimens of this mammal were studied by both direct cultivation of their viscera (spleen, liver and lungs) and by inoculation of Swiss mice by the intraperitoneal route with a suspension of fragments of these viscera. No fungal growth or structures similar to this fungus were detected. Probably D. albiventris is not frequently infected with P. brasiliensis.     

Cytogenetic Analysis of A- and B-Chromosomes of Prochilodus Lineatus (Teleostei, Prochilodontidae) Using Different Restriction Enzyme Banding and Staining Methods

Different cytogenetic techniques were used to analyse the chromosomes of Prochilodus lineatus with the main objective of comparing the base composition of A- and B-chromosomes. The results of digestion of chromosomes with 10 different restriction endonucleases (REs), silver staining, CMA₃ staining and C-banding indicated the existence of different classes of highly repetitive DNA in the A-set and also suggested the existence of compositional differences between the chromatin of A- and B-chromosomes. The 5-BrdU incorporation technique showed a late replicating pattern in all B-chromosomes and in some heterochromatic pericentromeric regions of A-chromosomes. The cleavage with RE BamHI produced a band pattern in all chromosomes of P. lineatus which permitted the tentative pairing of homologues in the karyotype of this species. We concluded that the combined use of the above techniques can contribute to the correct identification of chromosomes and the karyotypic analysis in fishes. On the basis of the results, some aspects of chromosome structure and the origin of the B-chromosomes in P. lineatus are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Intracameral bevacizumab and mitomycin C Trabeculectomy for eyes with neovascular glaucoma: a case series

The purpose of this study was to describe the surgical outcomes and safety of intracameral bevacizumab during trabeculectomy in eyes with neovascular glaucoma. Pilot study included four eyes (four patients) with refractory neovascular glaucoma submitted to fornix-based trabeculectomy with adjunctive use of bevacizumab in the anterior chamber during the procedure. Patients were previously treated with panretinal photocoagulation as standard therapy. Variables evaluated were intraocular pressure, bleb appearance, iris neovascularization, intraoperative/postoperative complications, and visual outcomes. No intraoperative complication was observed. The mean follow-up period was 12.75 (range, 12–15 months). All eyes showed significant intraocular pressure control postoperatively. Iris neovascularization reduced significantly within 1 month after surgery. Mild anterior chamber inflammation was observed during follow-up in all eyes. No significant postoperative complication was observed, and no patient presented visual acuity deterioration. Intracameral bevacizumab may be used as an adjunctive therapy during trabeculectomy in eyes with neovascular glaucoma.     

Genetic diversity and statistical parameters of 15 autosomal STR loci in the Pomeranian Subpopulation of Espirito Santo State,Brazil

Allelic frequencies and other population data analysis are reported for the 15 autosomal Short Tandem Repeats (STR) loci included in the PowerPlex^®16 kit (CSF1PO, D13S317, D16S539, D18S51, D21S11, D3S1358, D5S818, D7S820, D8S1179, FGA, Penta D, Penta E, TPOX, TH01 and vWA) in Pomeranian’s descendants from the Espirito Santo State (ES), Brazil, third largest population of Pomeranian’s descendants in the world. They chose the mountain region of the state for their preferred geographic location, and they have a very peculiar lifestyle with a selective mating behavior which has maintained their characteristics as a relatively pure subpopulation. Blood samples were obtained from 82 unrelated volunteers from 11 different cities of Espirito Santo State, where there are the Pomeranian’s descendants. All 15 loci analyzed showed Power of Discrimination (PD) values > 0.75. Except the TPOX locus, all analyzed loci were at Hardy–Weinberg equilibrium. This subpopulation has not yet been characterized for STR allelic frequencies used for forensic and genetic identification studies.     

Rudgea viburnoides (Rubiaceae) overcomes the low soil fertility of the Brazilian Cerrado and hyperaccumulates aluminum in cell walls and chloroplasts

Plant and Soil - Rudgea viburnoides (Cham.) Benth. is an aluminum (Al) hyperaccumulator species native to the Brazilian Cerrado and can be found on soils with different fertilities and Al...