Agilent Technologies (Brazil)

Extraíveis orgânicos são compostos que podem ser extraídos de elastômeros, plásticos e revestimentos do material de embalagem do medicamento, na presença de solvente(s) e/ou condição(ões) apropriado(s). A importância dos extraíveis está relacionada à sua identidade, concentração e toxicidade, pois pertencem a uma categoria de impurezas denominadas lixiviáveis, que podem estar presentes no medicamento, afetando sua segurança, qualidade e eficácia. Este artigo analisou padrões de referência conhecidos como extraíveis de materiais de embalagem por cromatografia à gás acoplada à espectrometria de massas (GC-MS), e suas identidades foram obtidas comparando-se o tempo de retenção, índice de retenção linear, os espectros de massas obtidos com a biblioteca instalada no equipamento e com a literatura, quando disponível. A partir dos padrões de referência dos extraíveis analisados, foi confirmada a identificação de um total de 17 compostos, os principais compostos presentes foram antioxidantes, plastificantes, monômeros e ácido esteárico. Seguindo a metodologia proposta, é possível utilizar os índices de retenção linear determinados neste artigo como referência em um novo experimento, visto que os índices de retenção linear aqui obtidos também foram comparados com os valores disponíveis na NIST e na literatura. Esta correlação possibilita a classificação da identificação de um extraível de uma categoria provisória, para confiável quando o padrão de referência não estiver disponível.

ABSTRACT Two stink bug-resistant soybean cultivars, Dowling and IAC 100, and one sucepible, Silvânia were selected to evaluate their influence on Euschistus heros development. Evaluation of the biology of E. heros was conducted on nymph development, adult longevity, female fecundity and egg fertility in seeds of each cultivar. The results showed that E. heros nymphs reared on cv Dowling did not complete their biological cycle, but it was completed on cvs Silvânia and IAC 100. The total amount of six isoflavonoids identified and one flavonol was higher in cv Silvânia compared to the levels quantified in cv Dowling. The results showed that cvs Dowling and IAC 100 have constitutive resistance affecting E. heros development and that the major falvonoids quantified in these cultivars are not involved in soybean antibiotic effect observed in this study.

The tolerance to metal toxicity, such as aluminium, can be induced by the formation of Al-Si complexes. Therefore, the aim of this research is to determine the contribution of Si on nutrient concentrations, compounds linked to oxidative stress, photosynthetic pigments and gas exchange and to determine if Si can improve the tolerance mechanism of young Eucalyptus platyphylla plants exposed to Al toxicity. The experimental setup was completely randomized with four treatments (0, 1.6 mmol/L Al, 2.0 mmol/L Si and 1.6 mmol/L Al + 2.0 mmol/L Si; being described as the control, Al toxicity, Si and Al toxicity + Si, respectively). The treatment with Si attenuated the negative effects of Al on nutrient concentrations by reducing superoxide, hydrogen peroxide, malondialdehyde and electrolyte leakage. Pigments and gas exchange exhibited beneficial effects after Si application, with positive interactions also being detected between Si-Al. Therefore, this study demonstrates that Si reduced the oxidative stress and improved the tolerance mechanism of young E. platyphylla plants exposed to Al toxicity.

Standard dilution analysis combined with synchronous vertical dual view ICP OES to determine nine elements in complex matrix samples using only two calibration solutions.

Simple procedures for the determination of Cr, Ni, Pb and V in gasoline and ethanol fuel by microwave plasma optical emission spectrometry (MIP OES) are described. Ethanol fuel samples were simply diluted in an aqueous 1% v/v HNO3 solution. For gasoline, microemulsions in n-propanol were prepared. The MIP OES instrument requires no separate gas source since a N2 gas generator coupled to a simple air compressor is sufficient to maintain the microwave-induced plasma. An external gas control module (EGCM) is used to inject air into the plasma in order to minimize background emissions and avoid carbon deposition on the torch and on the pre-optical window. The Flow Blurring Nebulizer (FBN) technology was also employed to ensure more efficient and homogeneous sample aerosols, which contributes to plasma stability and lower limits of detection (LODs). Nebulizer gas pressure and plasma viewing position were optimized separately for each analyte. Gasoline and ethanol fuel samples were analyzed and the calculated LODs were in the range of 0.3–60 μg L−1 or 4–1700 μg kg−1 for all analytes. The accuracy was checked by spike experiments and recoveries between 84 and 123% were obtained.

Transposable elements (TEs) are considered to be important components of the maintenance and diversification of genomes. The recent increase in genome sequence data has created an opportunity to evaluate the impact of these active mobile elements on the evolution of plant genomes. Analysis of the sugarcane transcriptome identified 267 clones with significant similarity to previously described plant TEs. After full cDNA sequencing, 68 sugarcane TE clones were assigned to 11 families according to their best sequence alignment against a fully characterized element. Expression was further investigated through a combined study utilizing electronic Northerns, macroarray, transient and stable sugarcane transformation. Newly synthesized cDNA probes from flower, leaf roll, apical meristem and callus tissues confirm previous results. Callus was identified as the tissue with the highest number of TEs being expressed, revealing that tissue culture drastically induced the expression of different elements. No tissue-specific family was identified. Different representatives within a TE family displayed differential expression patterns, showing that each family presented expression in almost every tissue. Transformation experiments demonstrated that most Hopscotch clone-derived U3 regions are, indeed, active promoters, although under a strong transcriptional regulation. This is a large-scale study about the expression pattern of TEs and indicates that mobile genetic elements are transcriptionally active in the highly polyploid and complex sugarcane genome.