Single spin-echo T 2 relaxation times of cerebral metabolites at 14.1 T in the in vivo rat brain.

OBJECT: To determine the single spin-echo T 2 relaxation times of uncoupled and J-coupled metabolites in rat brain in vivo at 14.1 T and to compare these results with those previously obtained at 9.4 T. MATERIALS AND METHODS: Measurements were performed on five rats at 14.1 T using the SPECIAL sequence and TE-specific basis-sets for LCModel analysis. RESULTS AND CONCLUSION: The T 2 of singlets ranged from 98 to 148 ms and T 2 of J-coupled metabolites ranged from 72 ms (glutamate) to 97 ms (myo-inositol). When comparing the T 2s of the metabolites measured at 14.1 T with those previously measured at 9.4 T, a decreasing trend was found (p < 0.0001). We conclude that the modest shortening of T 2 at 14.1 T has a negligible impact on the sensitivity of the (1)H MRS when performed at TE shorter than 10 ms.

Efeitos de mbta [cloridrato de n,n-dietil-2-(4-metilbenziloxi) etilamina] na produtividade e na qualidade dos frutos da laranjeira 'pêra' (Citrus sinensis L. Osbeck)

O objetivo deste trabalho foi avaliar os efeitos do biorregulador MBTA [cloridrato de N,N-dietil-2-(4-metilbenziloxi) etilamina] aplicado em diferentes épocas e concentrações na produtividade e qualidade dos frutos da laranjeira 'Pêra'. Em duas safras consecutivas, o MBTA foi aplicado em três diferentes concentrações (8; 16 e 32 mg L-1) e em duas diferentes fases fenológicas (25% e 100% de flores abertas), em árvores cítricas adultas, utilizando um volume de 7 litros de solução por planta, acompanhado do adjuvante Silwett L-77 0,05%. Foram amostrados 20 frutos por planta, em quatro diferentes épocas estudadas, para determinar o teor de sólidos solúveis (SS); acidez titulável (AT); quantidade de sólidos solúveis por caixa de 40,8 kg; pH; rendimento de suco; "ratio" (relação SS/AT), e a massa média dos frutos. Os efeitos do MBTA variaram de acordo com a concentração aplicada e com a fase fenológica de aplicação. O MBTA, na concentração de 8 mg L-1, aplicado com 25% das flores abertas, incrementou o teor de sólidos solúveis, a acidez, a quantidade de sólidos solúveis por caixa de 40,8 kg e a produtividade. Esse mesmo tratamento também reduziu a massa média dos frutos e não alterou o rendimento de suco e o "ratio" do suco dos frutos. O incremento médio foi de 0,49 a 0,65% na concentração de sólidos solúveis, de 0,11 a 0,13 kg na quantidade de sólidos solúveis por caixa de 40,8 kg e de 20,4 kg/planta na produtividade.

Long-term X-ray variability of the microquasar system LS5039/RX J1826.2-1450

We report on the results of the spectral and timing analysis of a BeppoSAX observation of the microquasar system LS 5039/RX J1826.2-1450. The source was found in a low-flux state with Fx(1-10 keV)= 4.7 x 10^{-12} erg cm^{-2} s^{-1}, which represents almost one order of magnitude lower than a previous RXTE observation 2.5 years before. The 0.1--10 keV spectrum is described by an absorbed power-law continuum with photon-number spectral index Gamma=1.8+-0.2 and hydrogen column density of NH=1.0^{+0.4}_{-0.3} x 10^{22} cm^{-2}. According to the orbital parameters of the system the BeppoSAX observation covers the time of an X-ray eclipse should one occur. However, the 1.6-10 keV light curve does not show evidence for such an event, which allows us to give an upper limit to the inclination of the system. The low X-ray flux detected during this observation is interpreted as a decrease in the mass accretion rate onto the compact object due to a decrease in the mass-loss rate from the primary.

Estructura cristalina del N-isopropil-2-ciano-3(5'-nitrofuril)acrilamida

C11H11N3O4 , Mr = 249.23, triclinic, , a = 5.453(1), b = 22.873(5), c = 4.893(1) Å, a = 94.47(3), b = 96.36(3), g = 86.27(3)º, V = 603.7(8)ų,Z = 2, Dx = 1.371 Mg/m-3,l(Cu Ka1) = 1.54178Å, m = 0.86mm-1, room temperature. The crystal structure of N-isopropyl-2-cyano-3(5'-nitrofuryl) - acrylamide has been determined by Direct Methods and refined to R = 0.086 for 797 observed reflections. The molecules in the crystal are packed at normal van der Waals forces and by an hydrogen bond between N1-H1...02i (N1...02i: 2.910(1)Å), with i=x,y,z+1).

Preludeja op. 17 nrot 2, 6, 9, 10, 11, 12, 15 & 23

Digitoitu 13. 8. 2008.

Novos constituintes químicos das cascas do caule de Tabebuia heptaphylla

A new triterpene, 3beta,6beta,21beta-trihydroxyolean-12-ene and a new iridoid, 8alpha-methyl-8beta-hydroxy-6beta-(3',4'-dimethoxy)benzoyloxy-1 alpha,3alpha-dimethoxy-octahydro-cyclopenta[c]pyran were isolated from the trunk bark of a specimen of Tabebuia heptaphylla (Bignoniaceae) collected in the "Pantanal" of Mato Grosso do Sul, Brazil. Twelve known compounds were also obtained in this work, comprising four iridoids, 6-O-p-hydroxybenzoylajugol, 6-O-p-methoxybenzoylajugol, 6-O-3",4"-dimethoxybenzoylajugol, 8alpha-methyl-8beta-hydroxy-6beta-(4'-hydroxy)benzoyloxy-1alpha,3 alpha-dimethoxy-octahydro-cyclopenta[c]pyran, a cyclopentene dialdehyde, 2-formyl-5-(3',4'-dimethoxybenzoyloxy)-3-methyl-2-cyclopentene-1-acetaldehyde, a phenylethanoid glycoside, verbascoside and three benzoic acid derivatives, p-hydroxybenzoic, p-methoxybenzoic and 3,4-dimethoxybenzoic acids, in addition to squalene, sitostenone and sitosterol. The antioxidant properties of the isolated compounds were also evaluated in this work.

Constituintes químicos e atividade antiedematogênica de Peltodon radicans (Lamiaceae)

Most of the snakebite incidents in the Amazon region involve Bothrops atrox, whose venom presents the most potent edematogenic and necrotic activities in the genus. This work describes the studies of isolation of the chemical constituents and antiedematogenic activity of the species Peltodon radicans (Lamiaceae), which is used in the treatment of snakebites and scorpion stings in the region. The extracts presented aliphatic hydrocarbons, 3beta-OH,beta-amirin (1), 3beta-OH,alpha-amirin (2), beta-sitosterol (3), stigmasterol (4), ursolic acid (5), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid (tormentic acid, 6), methyl 3beta-hydroxy,28-methyl-ursolate (7), sitosterol-3-O-beta-D-glucopyranoside (8), and stigmasterol-3-O-beta-D-glucopyranoside (9). The flower extracts presented the higher antiedematogenic activity. This is the first report on the study of the flowers, stem, and roots of this plant.