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Search Results: 1 - 10 of 16372 matches for " Ronaldo do Nascimento "
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Crescimento e teor de proteínas em sementes de soja sob influência de horm?nios vegetais
Nascimento, Ronaldo do;Mosquim, Paulo R.;
Brazilian Journal of Botany , 2004, DOI: 10.1590/S0100-84042004000300016
Abstract: the phytohormones likely to be envolved in growth and protein reserve accumulation in soybean seeds were studied by artificial cultivation of fruits. explants from soybean fruits with pericarp fully expanded and seeds with 100 mg of fresh mass were cultivated in vitro with naphthalene acetic acid (naa), gibberelic acid (ga3), benzylad enine (ba) and abscisic acid (aba) initially alone at 10-7, 10-6, 10-5 and 104 mol.l-1 rates. phytoregulators combinations were determined as a function of greater increments in seeds dry weight. on the basis of previous observations of. ga3 and ba promoted seed development only in high concentrations, while naa was ineffective and aba inhibited seed growth. when applied concurrently with ga3 or ba, the naa stimulated seed growth, suggesting that interactions may occur among them. naa and ba alone or combined induced increase in seed protein content but aba inhibited the protein accumulation. the artificial cultivation system employed in this assay has been shown to be suitable for studies of growth and protein accumulation in soybean seeds.
Efeito do ácido giberélico e diferentes aminoácidos sobre as atividades da sintetase da glutamina e sintase do glutamato e sobre o crescimento de frutos de soja
Nascimento, Ronaldo do;Mosquim, Paulo R.;
Brazilian Journal of Botany , 2004, DOI: 10.1590/S0100-84042004000100008
Abstract: the work had as objective to evaluate the effect of different aminoacids and of the gibberelic acid (ga) on the activity of glutamine synthetase (gs) and glutamate synthase (gogat) and the growth of soybean fruits. immature fruits were cultivated with different paclobutrazol (pbz) concentrations, inhibitor gibberellin synthesis, which it inhibited the growth of the fruits in up to 80%. in a second stage, the effect of the ga was evaluated on the growth of the soybean fruits cultivated with pbz. the growth regulator reestablished the growth of the cultivated fruits with 0,034 mm pbz. however, with 0,85 mm pbz it was not obtained the same positive effect, indicating a possible level phytotoxic. following fruits was cultivated during eight days, with glutamine, asparagine or allantoine, with or without ga, after which the enzymatic activities were determined. the enzymes of assimilation of the nitrogen went more active under presence of the allantoine. the ga inhibited the gs activity and it stimulated the of fd-gogat and of nadh-gogat. the fd-gogat activity went superior of the nadh-gogat, perhaps due to reduced ferredoxin in the cultivated fruits under constant illumination, advent of the photosynthetic. the results indicate that, probably, gibberellins are involved in the growth of immature fruits of soybean and in regulation enzymatic activities of the gs and gogat in that fruits.
Initial Growth and Gas Exchanges of Plants of Colored Cotton Submitted to Saline Stress  [PDF]
Hallyson Oliveira, Ronaldo do Nascimento, Samuel Silva, José Alberto Ferreira Cardoso, Rafaela Felix Basílio Guimar?es, Elka Costa Santos Nascimento
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.912115
Abstract: The objective of the research was to evaluate the effects of saline stress on the initial growth and physiological parameters of three varieties of cotton plants, being two cultivars of colored fiber (BRS Topázio and BRS Verde) and one of white fiber (BRS 286). The experiment was conducted under greenhouse conditions. After chemical depletion with sulfuric acid, five seeds were seeded in polyethylene pots of 20 kg, leaving only one plant per pot after thinning. The experimental design was completely randomized, with a factorial scheme of 3 × 5, with five replications, totaling 75 plots, being three cotton varieties and five saline stress treatments—1.1; 3.1; 5.1; 7.1; 9.1 dS m1. The evaluations occurred at 15 and 30 days after the beginning of the treatments (DAT) for growth variables (plant height, stem diameter, number of leaves and leaf area) and gas exchange (stomatal conductance, net photosynthesis rate and transpiration. The variety that was most resistant to the salt stress levels studied was BRS 286, followed by BRS Topazio and BRS Verde.
Palladium(0)-catalyzed efficient synthesis of allylic N- and S-benzoheterocycles linked to unsaturated carbohydrate derivatives
Ronaldo Nascimento de Oliveira,Wilson S. do Nascimento,Girliane R. da Silva,Tania Maria S. Silva
Orbital : the Electronic Journal of Chemistry , 2012,
Abstract: An efficient strategy was developed to envisage the synthesis of new N- and S-benzoheterocycles attached to the C-4 position of pseudo-carbohydrates. The reaction was performed with unsaturated carbohydrates and benzoheterocycles as nucleophiles in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) and chelating bidentate ligand dppb. This strategy allowed easy access to benzoheterocyclic sugars in moderate-to-good yields. A preliminary study for antioxidant activities of O-glycosides 2,3-unsaturated was evaluated based on the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and 2,2-azinobis 3-ethylbenzothiozoline-6-sulfonic acid (ABTS) radical cation decolorization assay, and showed low-to-moderate activities.
Synthesis of 1,4-naphthoquinone derivatives using 1,3-dipolar cycloaddition and Sonogashira reactions Síntese de derivados da 1,4-naftoquinona utilizando a rea o de cicloadi o 1,3-dipolar e a rea o de Sonogashira
Wilson Silva do Nascimento,Mauro Gomes da Silva,Ronaldo Nascimento de Oliveira,Celso Amorim Camara
Orbital : the Electronic Journal of Chemistry , 2010,
Synthesis of 1,4-naphthoquinone derivatives using 1,3-dipolar cycloaddition and Sonogashira reactions
Wilson Silva do Nascimento,Mauro Gomes da Silva,Ronaldo Nascimento de Oliveira,Celso Amorim Camara
Orbital : the Electronic Journal of Chemistry , 2010,
Abstract: Naphthoquinones are known according to their important bio-activities, such as their antitumoral and topoisomerase inhibition properties. From 2-azido (3) or 2,3-diacetylene-1,4-naphthoquinone (4) it was possible to obtain triazole derivatives (naphthoquinonic). This work describes the synthesis of two novel molecules, with triazole groups linked to 1,4-naphthoquinone using the 1,3-dipolar cycloaddition and Sonogashira reactions. The synthetic strategy followed two routes (Scheme 1). First, we synthesized the 2-bromo-1,4-naphthoquinone (2, yield 98%) by using Br2 and CH3CO2H, and then used it to obtain 2-azido-1,4-naphthoquinone (3, yield 62%) from compound 1, along with ethanolic solution (reflux) and NaN3. Finally, we prepared 1,2,3-triazole compounds (4a, b) by 1,3-dipolar cycloaddition, involving compound (3) and terminal acetylenes (phenylacetylene, a) and glycoside (b) using Cu(OAc)2 and ascorbate, under argon atmosphere. During the second step, 2,3-dibromo-1,4-naphthoquinone was prepared using Br2/CH2Cl2 at room temperature. From compound (5) it was possible to synthesize (6), catalyzed by Pd(PPh3)2Cl2/CuI/Et3N, under argon atmosphere, in 40% yield. The 1,3-dipolar cycloaddition reactions involving 2-azido-1,4-naphthoquinone (3) and alkynes (a, yield 23% and b, yield 30%) were conducted using the solvent system, (1:1) terc-BuOH/H2O/r.t/ 20 mol% of Cu(OAc)2 and sodium ascorbate, under stirring during 24 hours. The reaction involving 2,3-dibromo-1,4-naphthoquinone (5, yield 65%) and phenylacetylene was prepared using the solvent mixture (2:1) DMSO/CHCl3 and catalytic amount of CuI/Pd(PPh3)2Cl2. The final products were characterized by elemental analysis and spectrometric techniques (IR, NMR 1H and 13C). Two novel triazole compounds were synthesized from naphthoquinones by 1,3-dipolar cycloaddition from suitable 1,4-naphthoquinones obtained by Sonogashira couplings.
Growth and Photosynthetic Pigments of Cotton Cultivars Irrigated with Saline Water  [PDF]
Elka Costa Santos Nascimento, Ronaldo do Nascimento, André Alisson Rodrigues da Silva, Carlos Vailan de Castro Bezerra, Mateus Costa Batista, Luana Lucas de Sá Almeida Veloso, Márcia Cristina de Araújo Pereira, Hallyson Oliveira
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.101007
Abstract: The cultivation of cotton is a relevant socioeconomic activity in the Brazilian agricultural scenario. In the Brazilian Northeast, however, production is limited by low rainfall, requiring water supplementation, a problem for the cotton cultivation practiced in the semi-arid region, due to the presence of saline ions in several water sources, from where the water is used for irrigation. It is necessary to identify cultivars that better tolerate saline stress in order to provide subsidies for their cultivation under such conditions. In this sense, the objective was to evaluate the tolerance of cotton cultivars to salinity. The experiment was conducted in a greenhouse, belonging to the Natural Resource Technology Center of the Federal University of Campina Grande, Campus I, Campina Grande, Brazil, in a completely randomized design in a 2 × 5 factorial scheme, with four replications, totaling 40 experimental units (BRS 368 RF and BRS SAFIRA) submitted to five saline levels (1.5, 3.0, 4.5, 6.0 and 7.5 dS·mˉ1). Irrigation with water saline of EC from 1.5 dS·mˉ1 affects adversely the growth of cotton cultivars, causing reductions in plant height, stem diameter, leaf area and number of leaves. Saline stress reduced the levels of the photosynthetic pigments of the cotton plants studied.
Aduba??o foliar e via solo de nitrogênio em plantas de milho em fase inicial de desenvolvimento
Deuner, Sidnei;Nascimento, Ronaldo do;Ferreira, Ladislau Soares;Badinelli, Pablo Gerson;Kerber, Romel Silva;
Ciência e Agrotecnologia , 2008, DOI: 10.1590/S1413-70542008000500001
Abstract: consider the most important nutrient in the increment of grain gield and also the proteic level, nitrogen (n), in addition of this fact, this nutrient is the component that most increases the production cost of maize crop. this study aimed to verify whether the application of leaf nitrogen influences the accumulation of proteins and parameters of growth of young plants of maize compared to the application of urea via soil. for both, young plants of the hybrid maize br 206 received applications of urea as a source of n via leaf and soil at concentrations of zero, 0.5% and 1.0%. the plants were grown in a greenhouse being held three applications of n, the first for six days after the emergency (dae) in a volume of 10 ml per plant and the following two to 10 and 14 dae with 20 ml each. at 18 dae the plants were collected and analyses proceeded. for plant height, root volum, leaf area, dry weigth of leaf area and root, one verified a higher efficiency of leaf fertilization, mainly at 0,5% level of urea. the application of urea 1,0% via soil caused a significative increase in leaf protein levels. these results suggest that leaf fertilization may be an efficient mode to complement what is uptaken by the roots, although it should not be used as a unique source of inorganic n to the plants.
Influência do material do destilador na composi??o química das aguardentes de cana: parte II
Cardoso, Daniel R.;Lima-Neto, Benedito S.;Franco, Douglas W.;Nascimento, Ronaldo F. do;
Química Nova , 2003, DOI: 10.1590/S0100-40422003000200004
Abstract: the quantitative chemical analysis of the brazilian sugar cane spirit distilled from glass column packaged with copper, stainless steel, aluminum sponge, or porcelain balls is described. the main chemical compounds determined by gas chromatography coupled with flame ionization (fid) and flame photometric (fpd) detectors and liquid chromatography coupled with diode array detector are aldehydes, ketones, carboxylic acids, alcohols, esters and dimethylsulfite (dms). the spirits produced either in columns filled with copper or aluminum pot still exhibits the lowest dms contents but the higher sulfate and methanol contents, whereas spirits produced in stainless steel or porcelain showed higher dms concentration and lower teors of sulfate ion and methanol. these observations are coherent with dms oxidation to sulfate, with methanol as by product, in the presence of either copper or aluminum.
Rosangela Vera,Ronaldo Veloso Naves,Jorge Luiz do Nascimento,Lázaro José Chaves
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v35i2.2253
Abstract: A regi o dos Cerrados brasileiros apresenta grande biodiversidade em seu ecossistema. As fruteiras nativas da regi o muito se destacam, com dezenas de espécies utilizadas pela popula o local para alimenta o. Na Central de Abastecimento de Goiás, a principal fruta nativa do cerrado comercializada é o pequi. O período de safra ocorre nos meses de setembro a fevereiro, e o fruto é proveniente de diferentes regi es dos Estados de Goiás, Minas Gerais, Tocantins e Bahia. Este trabalho teve como objetivo avaliar as características físicas dos frutos de pequizeiros oriundos de cinco regi es do Estado de Goiás. Em cada regi o, identificaram-se três sub-popula es de pequizeiros, denominadas por áreas. Em cada área, elegeram-se cinco árvores para a coleta dos frutos. Foram analisadas as características físicas: massas do fruto, da casca, do caro o, da polpa e da amêndoa; dimens es do fruto e do caro o, espessura da casca e cor da polpa. Os resultados indicaram que há diferen as nas características físicas estudadas entre os frutos das diferentes regi es. A polpa fresca comestível representa 8,53% da massa dos frutos. As diferen as nas características físicas dos frutos ocorrem, principalmente, em frutos dentro de plantas, em plantas dentro de áreas e entre as regi es estudadas. PALAVRAS-CHAVE: Frutos do cerrado; pequi; fruteira nativa. The Brazilian Cerrado region presents large biodiversity in its ecosystem. Native fruit trees stand out, with tens of species used by locals for feeding. In the Goiás legumes and fruits victualling center (Central de Abastecimento de Goiás ? CEASA), the most commercialized Brazilian Cerrado fruit is pequi. The harvest period occurs from September to February, the fruit originating from different regions of Goiás, Minas Gerais, Tocantins, and Bahia states. This research had as objective to evaluate physical characteristics of pequi tree fruits from five Goiás state regions. Three subpopulations in each region, called areas, were identified. In each area, five trees were chosen for fruit sampling. Physical characteristics analyzed were fruit mass, peel, pit, pulp and almond; fruit and pit dimensions; peel thickness and pulp color. Results indicate differences in fruits physical characteristics for regions. The edible fresh pulp represents 8.53% of fruit mass; differences in physical characteristics of fruits were observed mainly in fruits within plants, in plants within areas and among areas. KEY-WORDS: Brazilian savannah; cerrado; pequi; native fruitfull.
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