6-Phenyl-5a,6,6a,7,12,13a-hexa­hydro-5H-benzo[6,7]indolizino[3,2-a]pyrrolizine

In the title compound, C23H22N2, the central pyrrolidine ring adopts an envelope conformation. The benzene ring of the hexa­hydro­pyrroloisoquinoline ring system makes dihedral angles of 83.43 (6) and 61.99 (10)°, respectively, with the phenyl and pyrrole rings. In the crystal structure, weak C—H⋯π inter­actions are observed

Identification of new genes in Sinorhizobium meliloti using the Genome Sequencer FLX system

<p>Abstract</p> <p>Background</p> <p><it>Sinorhizobium meliloti </it>is an agriculturally important model symbiont. There is an ongoing need to update and improve its genome annotation. In this study, we used a high-throughput pyrosequencing approach to sequence the transcriptome of <it>S. meliloti</it>, and search for new bacterial genes missed in the previous genome annotation. This is the first report of sequencing a bacterial transcriptome using the pyrosequencing technology.</p> <p>Results</p> <p>Our pilot sequencing run generated 19,005 reads with an average length of 136 nucleotides per read. From these data, we identified 20 new genes. These new gene transcripts were confirmed by RT-PCR and their possible functions were analyzed.</p> <p>Conclusion</p> <p>Our results indicate that high-throughput sequence analysis of bacterial transcriptomes is feasible and next-generation sequencing technologies will greatly facilitate the discovery of new genes and improve genome annotation.</p

Evidence for the evolutionary steps leading to mecA-mediated ß-lactam resistance in staphylococci

The epidemiologically most important mechanism of antibiotic resistance in Staphylococcus aureus is associated with mecA–an acquired gene encoding an extra penicillin-binding protein (PBP2a) with low affinity to virtually all β-lactams. The introduction of mecA into the S. aureus chromosome has led to the emergence of methicillin-resistant S. aureus (MRSA) pandemics, responsible for high rates of mortality worldwide. Nonetheless, little is known regarding the origin and evolution of mecA. Different mecA homologues have been identified in species belonging to the Staphylococcus sciuri group representing the most primitive staphylococci. In this study we aimed to identify evolutionary steps linking these mecA precursors to the β-lactam resistance gene mecA and the resistance phenotype. We sequenced genomes of 106 S. sciuri, S. vitulinus and S. fleurettii strains and determined their oxacillin susceptibility profiles. Single-nucleotide polymorphism (SNP) analysis of the core genome was performed to assess the genetic relatedness of the isolates. Phylogenetic analysis of the mecA gene homologues and promoters was achieved through nucleotide/amino acid sequence alignments and mutation rates were estimated using a Bayesian analysis. Furthermore, the predicted structure of mecA homologue-encoded PBPs of oxacillin-susceptible and -resistant strains were compared. We showed for the first time that oxacillin resistance in the S. sciuri group has emerged multiple times and by a variety of different mechanisms. Development of resistance occurred through several steps including structural diversification of the non-binding domain of native PBPs; changes in the promoters of mecA homologues; acquisition of SCCmec and adaptation of the bacterial genetic background. Moreover, our results suggest that it was exposure to β-lactams in human-created environments that has driven evolution of native PBPs towards a resistance determinant. The evolution of β-lactam resistance in staphylococci highlights the numerous resources available to bacteria to adapt to the selective pressure of antibiotics

Ethyl 3,5-dimethyl-1H-pyrrole-2-carboxyl­ate

In the title compound, C9H13NO2, there are two independent mol­ecules per asymmetric unit. The mol­ecules are very similar and almost planar, with the ethoxy­carbonyl group anti to the pyrrole N atom. The two independent mol­ecules are joined into dimeric units by strong hydrogen bonds between NH groups and carbonyl O atoms

Guia prático para interpretação de resultados de análises de solos.

bitstream/item/142260/1/Doc-206.pd

O Eletrocardiograma de Alta Resoluçao e suas Aplicaçoes Clínicas

O eletrocardiograma de alta resoluçao (ECGAR) é um registro obtido por meio de técnicas de amplificaçao de sinais elétricos de baixa amplitude e alta freqüência, permitindo a detecçao de potenciais elétricos de baixa voltagem que podem ocorrer na porçao terminal do QRS e que representam áreas de conduçao elétrica lenta e fracionada. A presença desses potenciais tem sido considerada como fator preditor de eventos arrítmicos fatais, de utilidade portanto na prevençao da morte súbita, especialmente nas cardiopatias isquêmicas, em que o seu valor diagnóstico já está bem estabelecido. Embora ainda sob investigaçao, o seu uso tem se estendido a cardiopatias de outras etiologias e a outras situaçoes, como no pós-operatório de cirurgia cardíaca, após terapia trombolítica e na investigaçao de síncope. Esta revisao tem como objetivo uma abordagem atualizada do método, suas aplicaçoes clínicas e limitaçoes