88 research outputs found
Grazing Management Flexibility in Pastures Subjected to Rotational Stocking Management: Herbage Production and Chemical Composition of Kikuyu-Grass Swards
Several recent papers published on tropical pastures have pointed out that under rotational stocking management regrowth should be interrupted when canopy light interception is 95% (LI). Further, these studies have revealed a positive and high correlation between LI and sward height, allowing LI management targets to be defined in terms of sward height. However, there are some indications that lower pre-grazing heights relative to those targets would result in similar leaf accumulation without interfering with sward persistence. The objective of this paper was to verify a possible flexibility of such pre-grazing height targets. A replicated experiment was conducted with treatments corresponding to four pre-grazing height targets (25 cm, corresponding to a canopy light interception of 95%; 20; 15 and 10 cm), which were associated with a single severity of grazing equivalent to removal of 50% of initial height, leaving four post-grazing heights (12.5, 10.0, 7.5 and 5 cm, respectively). Preliminary results indicated that there were no differences in rate of herbage accumulation, herbage yield and crude protein, NDF and ADF contents on swards managed with the pre-grazing targets of 15, 20 and 25 cm. Swards managed with the 10 cm pre-grazing target had the highest contents of CP and lowest contents of NDF and ADF, but herbage accumulation was reduced. Overall, the findings indicate that there may be some flexibility in targets of pre-grazing sward height, provided that defoliation severity is moderate and does not interfere with herbage yield and quality. In that context, targets of pre-grazing sward height defined in terms of canopy light interception would correspond to the maximum value of the possible range of values to be used
APLICAÇÃO DE BIOTECNOLOGIA NA PRODUÇÃO DE PADRÕES DE REFERÊNCIA DE METABÓLITOS DE CLONAZEPAM
Introdução e objetivos: O clonazepam é um agente antiepiléptico bastante útil na terapêutica. Oprincipal metabólito descrito é um produto de redução do grupamento nitro. Métodos paradeterminação do clonazepam e seus metabólitos no plasma apresentam várias aplicações clínicas,toxicológicas e forenses e requer padrões de referência. Baseando-se no uso de enzimas fúngicas,o modelo microbiano do metabolismo animal pode ser uma alternativa para obtenção demiligramas de metabólitos com menor custo e maior eficiência se comparado aos modelosanimais. O objetivo deste trabalho foi produzir metabólitos do clonazepam para depois utilizá-loscomo padrão de referência. Metodologia: Uma solução em acetona de clonazepam 50 mg⋅mL-1 foiincubada, em meio líquido PDSM em shaker a 27±2 °C e 200 rpm, por 144 horas, com fungosfilamentosos (Beauveria Bassiana ATCC 7159, Cunninghamella elegans ATCC 9244, Chaetomiumindicum LCP 984200) cultivados por 65 horas. Os derivados produzidos foram monitorados porcromatografia em camada delgada (CCD), purificados por coluna cromatográfica (CC) eidentificados por GC-MS. Resultados e discussões: Todas as cepas utilizadas foram capazes debiotransformar clonazepam. Após a purificação 03 metabólitos foram isolados, sendo um delesidentificado como o metabólito encontrado em humanos: 7-acetamido-clonazepam. Conclusões:Os resultados demonstram o grande potencial da metodologia para a preparação de compostosde referência de metabólitos do clonazepam
Enzymatic inhibition studies of selected flavonoids and chemosystematic significance of polymethoxylated flavonoids and quinoline alkaloids in Neoraputia (Rutaceae)
Our taxonomic interest in the Neoraputia stimulated an investigation of N. paraensis searching for alkaloids. Fractions were monitored by ¹H NMR and ESI-MS/MS and only those which showed features of anthranilate alkaloids and flavonoids absent in the previous investigations were examined. Stems afforded the alkaloids flindersine, skimmianine, 8-methoxyflindersine and dictamnine; leaves yielded 3',4',7,8-tetramethoxy-5,6-(2,2-dimethylpyrano)-flavone, 3',4',5,7,8-pentamethoxyflavone, 5-hydroxy-3',4',6,7-tetramethoxyflavone, 3',4'-methylenedioxy-5,6,7-trimethoxyflavone and 5-hydroxy-3',4'-methylenedioxy-6,7-dimethoxyflavone. The alkaloids have remained undiscovered for 10 years. A number of flavonoids isolated from N. paraensis, N. magnifica, Murraya paniculata, Citrus sinensis graft (Rutaceae), Lonchocarpus montanus (Leguminosae) were evaluated for their ability to inhibit the enzymatic activity of the protein glyceraldehyde-3-phosphate dehydrogenase from Trypanosoma cruzi. Highly oxygenated flavones and isoflavone were the most actives.Nosso interesse quimiotaxonômico sobre Neoraputia nos estimulou a examinar N. paraensis, visando a busca de alcalóides. As frações foram monitoradas via RMN ¹H e ESI-EM/EM e foram analisadas somente aquelas cujos espectros apresentavam características de alcalóides do ácido antranílico e flavonóides não isolados anteriormente. Foram isolados do caule os alcalóides flindersina, skimmianina, 8-metoxiflindersina e dictamnina; das folhas os flavonóides 3',4',7,8-tetrametoxi-5,6-(2,2-dimetilpirano)-flavona, 3',4',5,7,8-pentametoxiflavona, 5-hidroxi-3',4',6,7-tetrametoxiflavona, 3',4'-metilenodioxi-5,6,7-trimetoxiflavona e 5-hidroxi-3',4'-metilenodioxi-6,7-dimetoxiflavona,. Os alcalóides do ácido antranílico não foram encontrados em dez anos. Vários flavonóides isolados de N. paraensis, N. magnifica, Murraya paniculata, enxerto de Citrus sinensis (Rutaceae) e Lonchocarpus montanus (Leguminosae) foram testados frente a gliceraldeído-3-fosfato desidrogenase de Trypanosoma cruzi, visando verificar seus potenciais em inibir a atividade da enzima. Os flavonóides polimetoxilados e um isoflavonóide foram os mais ativos.380387Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Down Syndrome Resulting from a Rare non-Robertsonian Translocation t(11;21)(p13;q22)
Introduction: Down syndrome (DS) is a common genetic disorder, occurring in approximately 1 in 700 births. It results from an extra copy (triplication) of the whole or part of the long arm of chromosome 21 caused by different cytogenetic alterations: free trisomy, Robertsonian translocations, mosaicism, duplication of the critical region and other structural rearrangements. Non-Robertsonian chromosome translocations are very rare events with few cases reported. Case Report: We identified the non-Robertsonian translocation t(11;21)(p13;q22) and two chromosomes 21 in a female child referred with a clinical diagnosis of trisomy 21. The infant developed the transient myeloproliferative disorder at 17 months. Cytogenetic analysis was performed in lymphocytes and bone marrow metaphases according to standard procedure - G banding and fluorescence in situ hybridization. The karyotype study of the parents revealed that her phenotypically normal mother carries the same reciprocal translocation. Conclusion: This is the second report of the translocation t(11;21)(p13;q22), the first one resulting in DS. This description expands knowledge about cytogenetic variability in the etiology of DS. Future studies are needed to investigate the long-term clinical effects of the trisomy 21 associated with t(11;21)(p13;q22)
Atividade inseticida de óleos essenciais de Pelargonium graveolens l'Herit e Lippia alba (Mill) N. E. Brown sobre Spodoptera frugiperda (J. E. Smith)
Insecticidal activity of essential oils of Pelargonium graveolens, Lippia alba and compounds geraniol, linalool, 1,8-cineole, limonene, carvone, citral and Azamax® were evaluated against Spodoptera frugiperda. Topical application assay showed essential oil of P. graveolens has acute toxicity against Spodoptera frugiperda larvae (third instar) with LD50 1.13 µg/mg per insect and LD90 2.56 µg/mg per insect. Three essential oils of L. alba also exhibited insecticidal activity with LD50 ranging from 1.20 to 1.56 µg/mg per insect and LD90 from 2.60 to 3.75 µg/mg per insect. Geraniol, linalool, carvone and citral caused significant mortality of 30, 90, 84 and 64% respectively, compared to negative control. The bioinsecticide, Azamax®, caused lower mortality than the compounds of the essential oils
Oficinas de boas práticas de fabricação: construindo estratégias para garantir a segurança alimentar
Produção do conhecimento em Enfermagem: da idéia da pesquisa à publicação em periódico qualificado
Animal performance and sward characteristics of two cultivars of Brachiaria brizantha (BRS Paiaguás and BRS Piatã)
Use of amplified Mycobacterium tuberculosis direct test in respiratory samples from HIV-infected patients in Brazil
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