Isotopic Labeling
Mostrando 1-12 de 81 artigos, teses e dissertações.
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1. Field 13C Pulse Labeling of Pea, Wheat, and Vetch Plants for Subsequent Root and Shoot Decomposition Studies
ABSTRACT Isotopic labeling of plants is useful in tracking the fate of carbon (C) from different plant parts in a soil-plant system when these parts decompose simultaneously. Pulse labeling is a relatively simple technique and is amenable for use in the field. Therefore, we evaluated a 13CO2 pulse-labeling method to label crop plants under subtropical field
Rev. Bras. Ciênc. Solo. Publicado em: 15/02/2018
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2. Eficiência de absorção de fósforo por diversas espécies de adubos verdes e aproveitamento desse nutriente pelas culturas de cana-de-açúcar e de arroz / Efficiency of phosphorus uptake by several species of green manure and use of this nutrient by crops of sugar cane and rice
Integration of green manures species, which immobilize P, with supplying mineral P sources is one of the most promising agronomic practices for improving the availability of P for the main crop in order to recover soil fertility, increasing soil organic matter and thus optimize the efficiency of mineral fertilizers. The objectives of this work was to select
Publicado em: 2010
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3. Adubação nitrogenada com uréia e adubos verdes na cultura do arroz e efeito residual no feijoeiro / Nitrogen fertilization with urea and green manures in rice crops and its residual effect in bean crop
The association of green manures and mineral N sources is becoming a promising option for nitrogen fertilizer management, with the objective of recovering the soil fertility, increase of soil organic matter, reduce the loss of mineral N from the readily available sources, and in the case of legume incorporate biologically fixed N to the soil. The objectives
Publicado em: 2008
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4. Espectroscopia de Ressonância Magnética Nuclear de 13C no estudo de rotas biossintéticas de produtos naturais
During the last five decades, as a result of an interaction between natural product chemistry, synthetic organic chemistry, molecular biology and spectroscopy, scientists reached an extraordinary level of comprehension about the natural processes by which living organisms build up complex molecules. In this context, 13C nuclear magnetic resonance spectroscop
Química Nova. Publicado em: 2007-02
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5. Balanço de nitrogênio e enxofre no sistema solo-cana-de-açúcar no ciclo de cana-planta / Nitrogen and sulfur balance in the soil-sugarcane system during the plant cane cycle
This works objective was to evaluate the use and distribution of nitrogen and sulfur added to the soil as fertilizers in the soil-sugarcane system (plant cane), using the stable isotopes 15N and 34S. The study also aimed to evaluate the contribution of nitrogen mineralized from sugar cane crop residues labeled with 15N and incorporated into the soil, in a co
Publicado em: 2007
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6. Oxidação de proteínas por oxigênio singlete: mecanismos de dano, estratégias para detecção e implicações biológicas
Proteins are potential targets for singlet molecular oxygen (¹O2) oxidation. Damages occur only at tryptophan, tyrosine, histidine, methionine, and cysteine residues at physiological pH, generating oxidized compounds such as hydroperoxides. Therefore, it is important to understand the mechanisms by which ¹O2, hydroperoxides and other oxidized products can
Química Nova. Publicado em: 2006-06
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7. Efeitos de extrato aquoso de folhas de Solanum lycocarpum St. Hil. no desenvolvimento inicial e na síntese protéica de plântulas de Sesamum indicum L.
Solanum lycocarpum St. Hil., the common wolf fruit, is a Cerrado shrub in which leaves and fruits present strong allelopathic potencial. It was previously shown that aqueous leaf extracts at 1% (w/v) inhibit root growth and root hair differentiation in sesame (Sesamum indicum L.) seedlings. Considering that the morphological changes observed in plants subjec
Publicado em: 2006
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8. Ions acilio : estrutura e reatividade na fase gasosa
The structure and reactivity in the gas phase of several acylium ions ( R-CO ) and their sulfur analogues were studied using pentaquadrupole mass spectrometry. Cyclic ionic ketal were formed via ketalization reactions of acylium ions with diols and analogues; the products were characterized via sequential MS spectra and isotopic labeling with R-C=O. The diss
Publicado em: 1999
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9. Estudo da reatividade de ions e moleculas por colisões dissociativas e reações ion-molecula em fase gasosa via espectrometria de massas pentaquadeupolar
To study the gas phase chemistry of ions and molecules, some enaminones, two heterocumulene C2NO2 isomers and several isomers of pyridinium, pyrimidinium, furanyl and thiophenyl ions were chosen as systems of interest. Enaminones, were chosen because they have been extensively studied in solution by our research group. Firstly, the eletrophilic addition of m
Publicado em: 1998
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10. Autoregulation of a bacterial σ factor explored by using segmental isotopic labeling and NMR
Bacterial σ factors combine with the catalytic core RNA polymerase to direct the process of transcription initiation through sequence-specific interactions with the −10 and −35 elements of promoter DNA. In the absence of core RNA polymerase, the DNA-binding function of σ is autoinhibited by its own N-terminal 90 amino acids (region 1.1), putatively by
National Academy of Sciences.
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11. LABELING OF PROTEINS BY ISOTOPIC AMINO ACID DERIVATIVES*
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12. Effect of Isotopic Label on Buoyant Density Determinations of Viral DNA in the Preparative Ultracentrifuge
The buoyant density of herpes simplex virus DNA may be significantly increased by isotopic labeling, particularly with 14C. The apparent increase in buoyant density may be readily calculated from the specific activity of the DNA and is easily demonstrated by isopycnic centrifugation in both the preparative and analytical centrifuge.