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Search Results: 1 - 10 of 336762 matches for " Elnatan B. de;Silva "
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Composi??o química volátil e n?o-volátil de Eupatorium ballotifolium Kunth, Asteraceae
Albuquerque, Maria Rose Jane R.;Santos, Hélcio S. dos;Souza, Elnatan B. de;Silva, Rochanne M. da;Menezes, Jane Eire Silva A. de;Pessoa, Otília Deusdênia L.;Braz-Filho, Raimundo;Costa, S?nia Maria O.;
Revista Brasileira de Farmacognosia , 2010, DOI: 10.1590/S0102-695X2010000400023
Abstract: this work describes the chemical composition of the essential oils and the isolation of eleven substances from eupatorium ballotifolium kunth, asteraceae. the essential oils were obtained by hydrodistillation, analyzed by gc/ms and evaluated towards the acetylcholinesterase enzyme. the oils yield was of 0.11% for the leaves and 0.03% for the stems. the main constituents of the oils were the sesquiterpenes β-caryophyllene (24.9 and 22.2%), spathulenol (17.7 and 12.4%) and epoxy-allo-aromadendrene (23.0 and 23.6%). from the hexane extract of the aerial part were isolated a mixture of sitosterol and stigmasterol, its glucosides, and the triterpenes taraxasteryl acetate and taraxasterol, while from the ethanol extract were obtained the flavonoids nepetin and 3-o-glucoside-quercetin. the triterpenes epi-friedelanol and dammara-20,24-dien-3β-ol were obtained from the hexane extract of roots, while the coumarin 11-hydroxy-11,12-di-hydroobliquine was obtained from the ethanol extract. the structures of all compounds were determinate based on spectroscopic methods such as ir, ms and 1h and 13c nmr
Ocorrência de auto-incompatibilidade homomórfica em Mitracarpus longicalyx E. B. Souza & M. F. Sales (Rubiaceae - Spermacoceae)
Souza, Elnatan B. de;Costa, Cristiana B. N.;Borba, Eduardo L.;
Brazilian Journal of Botany , 2007, DOI: 10.1590/S0100-84042007000200012
Abstract: the breeding system of mitracarpus longicalyx was studied from september to december 2004 at feira de santana, ba, brazil. this species is an annual herb found in the "caatinga" of northeastern brazil, flowering between june and december. the inflorescences are glomerules with ca. 90 flowers. each flower has a white 4-5 mm long hypocrateriform corolla. the flowers are protandrous with a three days long staminate phase followed by a five days long pistilate phase. no overlapping between phases was observed within a flower, but flowers in different phases appear in the same inflorescence. m. longycalyx is psycophilous species, pollinated by hemiargus hanno hanno (stoll, 1790) (lycaenidae). hand-pollination tests indicated that m. longicalyx is a self-incompatible, non-agamospermous species, with high fruit set under natural conditions (97.8%) in the studied population; fruit set was also high (82.3%) with hand cross-pollinations but geitonogamous hand pollination gave zero fruit set. out-crossed pollen tubes reached the ovary within 24h after pollination, while selfed pollen grains failed to germinate or selfed pollen tubes failed to penetrate the stigmatic papillae. the results indicate that m. longicalyx has homomorphic self-incompatibility, possibly of the sporophytic type, in addition to protandry. homomorphic self-incompatibility is very rare in the rubiaceae, a family with abundant occurrence of heteromorphic self-incompatibility.
Briófitas de um remanescente de Mata Atlantica no Município de Ubajara, CE, Brasil
Siqueira, Samylia Mayra da Costa;Costa, Patrícia Silva;Souza, Elnatan Bezerra de;Oliveira, Hermeson Cassiano de;
Hoehnea , 2011, DOI: 10.1590/S2236-89062011000400006
Abstract: this paper presents the survey of the bryophytes of the remnant of atlantic forest, in the municipality of ubajara, ceará state, brazil. were recorded 102 species in 53 genera and 29 families. lejeuneaceae and fissidentaceae were the families with larger specific richness. aphanolejeunea kunertiana steph., groutiella apiculata (hook.) h.a. crum & steere, lophocolea liebmanniana gottsche, orthostichopsis praetermissa w.r. buck, and o. tortipilis (müll. hal.) broth. are recorded for the first time to ceará state.
O gênero Staelia Cham. & Schltdl. (Rubiaceae - Spermacoceae) no Estado de Pernambuco, Brasil
Souza, Elnatan Bezerra de;Sales, Margareth Ferreira de;
Acta Botanica Brasilica , 2004, DOI: 10.1590/S0102-33062004000400023
Abstract: this work presents a taxonomic study of the species of staelia present in the state of pernambuco. four specieswere found: s. aurea k. schum., s. galioides dc., s. vestita k. schum. and s. virgata (roem. & schult.) k. schum. a key to identify the species, descriptions, comments, illustrations and a geographic distribution map are provided.
óleos essenciais das folhas de Vernonia Remotiflora e Vernonia Brasiliana: composi??o química e atividade biológica
Maia, Ana Isabel V.;Torres, Maria Concei??o M.;Pessoa, Otília Deusdênia L.;Menezes, Jane Eire S. A. de;Costa, S?nia Maria O.;Nogueira, Vanessa Lúcia R.;Melo, Vania Maria Maciel;Souza, Elnatan B. de;Cavalcante, Maria Gilvania B.;Albuquerque, Maria Rose Jane R.;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000300018
Abstract: the chemical composition of the essential oils, obtained by hidrodistillation, from leaves of two vernonia species (v. remotiflora and v. brasiliana), was determined by gc-fid and gc-ms. both essential oils were predominantly constituted by sesquiterpenes (92.0 - 93.4%). the main constituents of the oil from v. brasilana were (e)-caryophyllene (36.7%), germacrene d (35.5%), and α-humulene (11.7%), while (e)-caryophyllene (42.2%) and bicyclogermacrene (20.0%) were the major ones in the oil from v. remotiflora. although with moderate activity both oils showed acetylcholinesterase and antibacterial activities.
Synthesis of ZSM-22 in Static and Dynamic System Using Seeds  [PDF]
Lenivaldo V. de Sousa Júnior, Antonio O. S. Silva, Bruno J. B. Silva, Soraya L. Alencar
Modern Research in Catalysis (MRC) , 2014, DOI: 10.4236/mrc.2014.32007
Abstract:

ZSM-22 was synthesized using various sources of silica, organic template 1,6-diaminohexane, under hydrothermal conditions, with and without agitation during crystallization. Subsequently, the crystallized material was used as seeds to accelerate the crystallization process. Characterization of the ZSM-22 samples was performed by XRD, ATG/DTG and FT-IR. It was found that it is possible to synthesize ZSM-22 employing colloidal silica and pyrolytic silica as silicon sources only if the system is stirred during crystallization. The crystallization time for these systems was 13 hours, longer times of crystallization do not significantly increase the crystallinity of the sample. The addition of seeds significantly accelerates the crystallization of ZSM-22, reducing the crystallization time to only 7 hours, with stirring and with systems employing colloidal silica.

Morphological Structure Characterization of PAH/NiTsPc Multilayer Nanostructured Films  [PDF]
Josmary R. Silva, Jackeline B. Brito, Sonia T. Tanimoto, Nara C. de Souza
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.211221
Abstract: Morphological structure and growth process of LbL nanostructured films from nickel tetrasulfonated phthalocyanine (NiTsPc) alternated with polyallylamine hydrochloride (PAH) were investigated. The experimental results of UV-visible adsorption kinetics (modeled by Johnson-Mehl-Avrami functions) and AFM images analyzes suggested that the surface morphology structure of films is formed by rod-shaped aggregates produced by a two-step growth process: nucleation and diffusion-limited growth.
The significance of lipid profile and positive troponin in predicting cardiac event
LDR De Silva,A Kumar,B Sathian
Kathmandu University Medical Journal , 2009, DOI: 10.3126/kumj.v7i3.2735
Abstract: Background: Diagnosis of Acute cardiac event in the early stage of its onset is important in the treatment process. The development of highly sensitive and specific immunoassays for myocardial proteins such as cardiac Troponin I (cTnI) had made it possible. However Troponin indicates cardiac events only after its onset or after cardiac tissue necrosis. Traditionally such high risk subjects were identified using lipid profiles. The identification of subjects with high risk of developing cardiac event in the future is more significant as it will provide time to prevent such incidents. Objectives: In this study we proposed to study the usefulness of traditional lipid profile levels in screening subjects who had developed chest pain due to cardiac event as indicated by a positive Troponin I test. Materials and methods: In this retrospective study data of the 259 patients presented to the emergency department with symptoms of cardiac ischemia who underwent both Troponin and lipid profiles tests were compared with the lipid profiles of 105 normal healthy subjects (controls). The Trponin was detected qualitatively when a specimen contains Troponin I (cTnI) above the 99th percentile (TnI >0.5 ng/ml). The Total cholesterol (TC), High density lipoproteins cholesterol (HDL), Very low density lipoproteins (VLDL), and Triacyl glycerol levels (TG) were also analysed and low density lipoprotein level (LDL) was calculated using Friedelwald formula. Results: Subjects with chest pain and positive Troponin test (with confirmed cardiac event) were found to have significantly elevated levels of TC, TG , LDL and significantly reduced HDL levels when compared to the subjects who had only chest pain (Negative Troponin) and healthy controls. Conclusion: Traditional lipid profile levels still can be used in screening populations to identify the subjects with high risk of developing cardiac event which is identified by highly sensitive and specific positive Troponin test.
An Econometric Analysis for the Behavior of the Bid-Ask Spread  [PDF]
H. de la Fuente-Mella, R. Campos-Espinoza, B. Silva-Palavecinos, D. Cademartori-Rosso
Open Journal of Social Sciences (JSS) , 2013, DOI: 10.4236/jss.2013.17001
Abstract:

Information asymmetries are an important element in the functioning of capital markets. An indirect means of measuring information asymmetry is through the spread of stock prices. The purpose of this paper is to identify the explanatory variables and the determinants of the bid-ask spread and to quantify the influence that the actors involved in the brokering of publically offered securities may have over the spread. The methodology used to model the time series for each of the analyzed companies is based on a time series from each of the observed econometric multivariate processes. The analysis shows a significantly negative relationship between the spread and the market-maker size, calculated in terms of both the equity and the stock portfolio; likewise, activity is measured by observing the amount offered for purchase and/or sale.

Fluxos de energia e desenvolvimento da cultura do abacaxizeiro
Souza, Cleber B. de;Silva, Bernardo B. da;Azevedo, Pedro V. de;Silva, Vicente de P. R. da;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2008, DOI: 10.1590/S1415-43662008000400011
Abstract: the canopy of the pineapple crop changes considerably during the growing season, from a leafless stage to a fully closed canopy at the end of the productive cycle. in order to evaluate the effects of the energy balance components on the developmental stage of the pineapple crop, a field experiment was carried out from march, 2001 to july, 2002 with pineapple crop, cv. perola, cultivated under supplemental irrigation conditions in the state of paraíba, brazil. the method of energy balance based on the bowen ratio was used to obtain energy balance components during the experimental period. the energy balance components were strongly affected by leaf area index and plant height during all developmental stages of the canopy, especially the sensible heat flux. results showed that the dry matter weight is totally independent of the energy partitioning. the sensible heat flux varied in function of the volume of water applied in irrigation during the experimental period.
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