Synthesis of 1,3-diazepines and ring contraction to cyanopyrroles

Several tetrazolo[1,5-a] pyridines/2-azidopyridines undergo photochemical nitrogen elimination and ring expansion to 1,3-diazacyclohepta-1,2,4,6-tetraenes (7,10,13,16,19,22) as well as ring cleavage to cyanovinylketenimines (8,17,20b) in low temperature Ar matrices. 6,8-Dichlorotetrazolo[1,5-a] pyridine/2-azido-3,5-dichloropridine 6 undergoes ready exchange of the chlorine in position 8 (3) with ROH/RONa. 8-Chloro-6-trifluoromethyltetrazolo[1,5-a] pyridine 15 undergoes solvolysis of the CF3 group to afford 8-chloro-6-methoxycarbonyltetrazolo[1,5-a] pyridine 18. Several tetrazolopyridines/2-azidopyridines afford 1H- or 5H-1,3-diazepines in good yields on photolysis in the presence of alcohols or amines (11,14,23,25). 5-Chlorotetrazolo[1,5-a] pyridines/2-azido-6-chloropyridines 21 and 38 undergo a rearrangement to 1H- and 3H-3-cyanopyrroles 27 and 45, respectively. The mechanism of this rearrangement was investigated by N-15-labelling and takes place via transient 1,3-diazepines. The structures of 6,8-dichloro-tetrazolo[1,5-a] pyridine 6T, 6-chloro-8-ethoxytetrazolo[1,5-a] pyridine 9Tb, dipyrrolylmethane 28, and 2-isopropoxy-4-dimethylamino-5H-1,3-diazepine 25b were determined by X-ray crystallography. In the latter case, this represents the first reported X-ray crystal structure of a 5H-1,3-diazepine.

Efeito da densidade de semeadura na produção do amendoim

In this work, the effects of sowing densities on peanut (Arachis hypogaea L.) crop, cv. Tatu were studied. Three experiments were carried out under field conditions on a soil classified as ''Latosol Roxo'', in the Municipality of Pontal, SP, during the wet seasons of 1987-88, 1988-89, and 1989-90. The densities studied were 7, 10, 13, 16, 19, 22, 25, and 28 seeds in one metter of row, under some row spacing of 0.60 m. The pod number per plant was the yield component responsible for the variation of pod production per plant and these decreased with the increase of sowing density. However. The low pod production per plant in high densities of sowing was compensated by the high populations of plants and these produced high yield. Thus, good pod yields were obtained, without significant losses of yield compared with the higher densities, at density of 13 seeds per meter, in 1987-88, 16 seeds per meter in 1988-89 and 10 seeds per meter in 1989-90, that resulted, respectively, in 11.36, 12.72 and 9.28 plants per meter at harvest time.

Estudo comparativo de inoculação do Lacazia loboi em camundongos BALB/C e B10.A, a partir de análise histopatológica, número de fungos e índice de viabilidade

Pós-graduação em Doenças Tropicais - FMB

Total phospholipid fatty acid concentrations structrures of ODP Hole 191-1179 samples (Table 1)

Sediment samples ranging from 0.05 to 278 m below sea floor (mbsf) at a Northwest Pacific deep-water (5564 mbsl) site (ODP Leg 191, Site 1179) were analyzed for phospholipid fatty acids (PLFAs). Total PLFA concentrations decreased by a factor of three over the first meter of sediment and then decreased at a slower rate to approximately 30 mbsf. The sharp decrease over the first meter corresponds to the depth of nitrate and Mn(IV) reduction as indicated by pore water chemistry. PLFA-based cell numbers at site 1179 had a similar depth profile as that for Acridine orange direct cell counts previously made on ODP site 1149 sediments which have a similar water depth and lithology. The mole percentage of straight chain saturated PLFAs increases with depth, with a large shift between the 0.95 and 3.95 mbsf samples. PLFA stable carbon isotope ratios were determined for sediments from 0.05 to 4.53 mbsf and showed a general trend toward more depleted d13C values with depth. Both of these observations may indicate a shift in the bacterial community with depth across the different redox zones inferred from pore water chemistry data. The PLFA 10me16:0, which has been attributed to the bacterial genera Desulfobacter in many marine sediments, showed the greatest isotopic depletion, decreasing from -20 to -35 per mil over the first meter of sediment. Pore water chemistry suggested that sulfate reduction was absent or minimal over this same sediment interval. However, 10me16:0 has been shown to be produced by recently discovered anaerobic ammonium oxidizing (anammox) bacteria which are known chemoautotrophs. The increasing depletion in d13C of 10me16:0 with the unusually lower concentration of ammonium and linear decrease of nitrate concentration is consistent with a scenario of anammox bacteria mediating the oxidation of ammonium via nitrite, an intermediate of nitrate reduction.

Phospholipid fatty acid and quinone composition of sediments from ODP Leg 205 sites

Assessing the habitability of deep-sea sediments undergoing compaction, compression, and subduction at convergent margins adds to our understanding of the limits of the terrestrial biosphere. In this work, we report exploratory biomarker data on sediments obtained at Ocean Drilling Program (ODP) Sites 1253, 1254, and 1255 during drilling at the Costa Rica subduction trench and forearc sedimentary wedge. The samples selected for postcruise biomarker analyses were located within intervals of potentially enhanced fluid flow within the décollement and sedimentary wedge fault zones (Sites 1254 and 1255) and within basal carbonates at the reference site (Site 1253). The passage of fluids that are geochemically distinct from ambient interstitial water provides a disequilibrium setting that may enhance habitability. Biomarker data show low levels of microbial biomass in subseafloor sediments sampled at the Costa Rica convergent margin as deep as ~370 meters below seafloor.

Cognitive effects following acute wild blueberry supplementation in 7 – 10 year old children

Purpose: Previously, anthocyanin-rich blueberry treatments have shown positive effects on cognition in both animals and human adults. However, little research has considered whether these benefits transfer to children. Here we describe an acute time-course and dose–response investigation considering whether these cognitive benefits extend to children. Methods: Using a double-blind cross-over design, on three occasions children (n = 21; 7–10 years) consumed placebo (vehicle) or blueberry drinks containing 15 or 30 g freeze-dried wild blueberry (WBB) powder. A cognitive battery including tests of verbal memory, word recognition, response interference, response inhibition and levels of processing was performed at baseline, and 1.15, 3 and 6 h following treatment. Results: Significant WBB-related improvements included final immediate recall at 1.15 h, delayed word recognition sustained over each period, and accuracy on cognitively demanding incongruent trials in the interference task at 3h. Importantly, across all measures, cognitive performance improved, consistent with a dose–response model, with the best performance following 30 g WBB and the worst following vehicle. Conclusion: Findings demonstrate WBB-related cognitive improvements in 7- to 10-year-old children. These effects would seem to be particularly sensitive to the cognitive demand of task.

Copper-64 Labeled Macrobicyclic Sarcophagine Coupled to a GRP Receptor Antagonist Shows Great Promise for PET Imaging of Prostate Cancer

The gastrin-releasing peptide receptor (GRPr) is an important molecular target for the visualization and therapy of tumors and can be targeted with radiolabeled bombesin derivatives. The present study aims to develop statine-based bombesin receptor antagonists suitable for labeling with 64Cu for imaging by positron emission tomography (PET). The potent GRPr antagonist D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 was conjugated to the sarcophagine (3,6,10,13,16,19-hexaazabicyclo[6.6.6] icosane=Sar) derivative 5-(8-methyl-3,6,10,13,16,19-hexaaza-bicyclo[6.6.6]icosan-1-ylamino)-5-oxopentanoic acid (MeCOSar) via PEG4 (LE1) and PEG2 (LE2) spacers and radiolabeled with 64Cu2+ with >95% yield and specific activities of about 100 MBq/nmol. Both Cu(II) conjugates have high affinity for GRPr (IC50: natCu-LE1, 1.4±0.1 nM; natCu-LE2, 3.8±0.6 nM). The antagonistic properties of both conjugates were confirmed by Ca2+-flux measurements. Biodistribution studies of Cu-64-LE1 exhibited specific targeting of the tumor (19.6±4.7% IA/g at 1 h p.i.) and GRPr-positive organs. Biodistribution and PET images at 4 and 24 h postinjection showed increasing tumor-to-background ratios with time. This was illustrated by the acquisition of PET images showing high tumor-to-normal tissue contrast. This study demonstrates the high affinity of the MeCOSar-PEGx-bombesin conjugates to GRPr. The stability of 64Cu complexes of MeCOSar, the long half-life of 64Cu, and the suitable biodistribution profile of the 64Cu-labeled peptides lead to PET images of high contrast suitable for potential translation into the clinic.