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Search Results: 1 - 10 of 745314 matches for " Giselle M.S.P.;Santos "
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Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae)
Moreira, Rafael Y.O.;Arruda, Mara S.P.;Arruda, Alberto C.;Santos, Lourivaldo S.;Müller, Adolfo H.;Guilhon, Giselle M.S.P.;Santos, Alberdan S.;Terezo, Evaristo;
Revista Brasileira de Farmacognosia , 2006, DOI: 10.1590/S0102-695X2006000300017
Abstract: the hexane extract of the bark of tectona grandis (verbenaceae) afforded two anthraquinones and two naphtoquinones. their caracterizations were obtained through nmr spectroscopic techniques. this is the first phytochemical study of the bark of tectona grandis reforestation specimen in brazil. the main interest in this work is proving the presence of tectoquinone in reforestation specimen.
Identification of (?)(E)-N-[2(S)-Hydroxy-2-(4-hydroxyphenyl) ethyl]ferulamide, a Natural Product Isolated from Croton Pullei: Theoretical and Experimental Analysis
Silvana de O. Silva,Rosana N.S. Peixoto,José Rogério A. Silva,Cláudio N. Alves,Giselle M.S.P. Guilhon,Lourivaldo S. Santos,Davi do S.B. Brasil
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12129389
Abstract: Ferulic acid (FA) and its derivatives (FADs) are known for a variety of biological activities, such as photo-protective agent, antioxidant, antiatherogenic and antiplasmodial activities. During structural definition of a FAD isolated from Croton pullei, the possibility of a heterologous series made this definition difficult. In this regard, computational simulations were performed using theoretical calculations at DFT level to predict Infrared (IR) and Nuclear Magnetic Resonance (NMR) data. The IR and NMR 13C and 1H data were compared with the theoretical calculations performed for three structural possibilities of a heterologous series. The theoretical results were compared with the experimental data through linear regression in order to define the most probable structure and showed satisfactory values.
Relationship of IL-1 and TNF-α polymorphisms with Helicobacter pylori in gastric diseases in a Brazilian population
Santos, J.C.;Ladeira, M.S.P.;Pedrazzoli Jr, J.;Ribeiro, M.L.;
Brazilian Journal of Medical and Biological Research , 2012, DOI: 10.1590/S0100-879X2012007500099
Abstract: it is well known that the risk of development of gastric cancer (gc) in helicobacter pylori-infected patients depends on several factors. thus, the aim of this study was to investigate the effect of proinflammatory cytokine gene polymorphisms for il-1β, il-1rn and tnf-α on the development of gc in a brazilian population. a total of 202 biopsies obtained from brazilian patients with chronic gastritis and gc were included in the study. infection with h. pylori caga+ was determined by the polymerase chain reaction (pcr) as previously described. il-1β, il-1rn and tnf-α polymorphism genotyping was performed by restriction fragment length polymorphism pcr. associations between gene polymorphisms, clinical diseases and virulence markers were evaluated using either the χ2 test or the fisher exact test. our results demonstrated that the il-1β -511 c/c and il-1β -511 c/t alleles were associated with chronic gastritis in h. pylori-positive patients (p = 0.04 and p = 0.05, respectively) and the il-1β -511 c/c genotype was associated with gc (p = 0.03). the frequency of il-1rn alleles from patients with chronic gastritis and gc indicated that there was no difference between the genotypes of the groups studied. similar results were found for tnf-α -308 gene polymorphisms. our results indicate that the il-1β -511 c/c and c/t gene polymorphisms are associated with chronic gastritis and gc development in h. pylori-infected individuals.
Potencial alelopático de Myrcia guianensis
Souza Filho, A.P.S.;Santos, R.A.;Santos, L.S.;Guilhon, G.M.P.;Santos, A.S.;Arruda, M.S.P.;Muller, A.H.;Arruda, A.C.;
Planta Daninha , 2006, DOI: 10.1590/S0100-83582006000400005
Abstract: the use of fire and mowing as weed methods have proved inefficient. although more efficient, synthetic chemical herbicides are usually related to environmental problems. thus, the search for natural herbicides has become a priority matter. based on these facts, research was conducted on myrcia guianensis (pedra-ume-caá) including the isolation and identification of chemical substances with allelophatic activity. the allelophatic effects of extracts, fractions, essential oils, and isolated chemical substances (gallic acid and protocatechuic acid) on germination and radicle and hypocotyl growth of weed species mimosa pudica (malícia) and senna obtusifolia (mata-pasto) were analyzed. extracts and fractions were analyzed at a concentration of 1%, essential oils at 15, 30, 45, 60 ppm and the isolated chemical substances at 15, 30, 45, 60 ppm. malicia showed more sensitivity to the allelophatic effects of extracts and fractions. the essential oil inhibited the germination of m. pudica but stimulated that of s. obtusifolia. the allelophatic effects of the chemical substances were concentration dependent and the strongest activity was observed at 60 ppm.
Efeito fungitóxico in vitro do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)
Deus, R.J.A.;Carvalho, A.S.C.;Banna, D.A.D.S.;Arruda, M.S.P.;Alves, C.N.;Santos, A.S.;
Revista Brasileira de Plantas Medicinais , 2009, DOI: 10.1590/S1516-05722009000300018
Abstract: copaifera multijuga hayne oil, crude and fractions, was evaluated for its in vitro fungitoxic activities against five species of filamentous fungi belonging to the genus aspergillus and three yeast species of the genus candida. oil-resin and essential oil concentrations ranging from 0.008 mg ml-1 to 1.6 mg ml-1 were used in qualitative and quantitative analyses. samples were placed onto 5mm-diameter paper disks and distributed on saboraud culture medium in petri dishes inoculated with conidia and incubated at 28oc during 10 days. a solution with 1.6 mg ml-1 of miconazole nitrate was used as positive control. qualitative results indicated that the oil-resin presented good fungistatic activity; however, one of the essential oil fractions was highly effective against candida parapsilosis ioc-2882, aspergillus flavus ioc-3874 and a. tamarii ioc-187, with inhibition halos of 16.0±1.4 mm, 19.5±2.1 mm and 12.5±3.5 mm, respectively. the quantitative evaluation indicated that 0.3 mg ml-1 of the oil-resin inhibited aspergillus flavus and candida parapsilosis growth, whereas 0.08 mg ml-1 of the essential oil fraction reached this same activity.
Single Stage Switching Power Supply With Half
International Journal of Engineering and Advanced Technology , 2012,
Abstract: Single stage switching power supply with half bridgetopology simulation for LED lamp Driver is presented in thispaper.LED lamp driver needs only dc supply. In this paper dcsupply is obtained as output while giving ac input voltage of 110V.It is formed by combination of ac/dc converter and dc/dc postregulator. Compared to other switching power supply this reducescost ,size and simplifies circuit design. It increases efficiency andoutput voltage can be controlled. The simulation of single stageswitching power supply using half bridge topology using Psimsoftware is done and output voltage and power are verified .byusing this get an output voltage of 48 V dc output and power rangeup to 120 W ,and efficiency is above .89 . It is used in LED lampdrivers and piezoelectric element drivers.
Potencial herbicida da biomassa e de substancias químicas produzidas pelo fungo endofítico Pestalotiopsis guepinii
Santos, L.S.;Oliveira, M.N.;Guilhon, G.M.S.P.;Santos, A.S.;Ferreira, I.C.S.;Lopes-Júnior, M.L.;Arruda, M.S.P.;Sailva, M.N.;Souza Filho, A.P.S.;Rodrigues-Filho, E.;Oliveira, M.C.F;
Planta Daninha , 2008, DOI: 10.1590/S0100-83582008000300009
Abstract: many of the chemical compounds found in nature that are produced by plants or microorganisms can offer new and efficient ways of controlling pests in agriculture and agricultural practice, with the help of fungi. the objective of this work is to characterize the inhibitory potential for seed germination and the plantlet development of two weed species using extracts and compounds obtained from biomass produced by pestalotiopsis guepinii, an endophytic fungus of the species virola michelii. the bioassays were developed under controlled conditions at 25 oc and 12-hour photoperiod for germination, and at 25 oc and 12-hour photoperiod for root and hypocotyl development. the crude extracts were analyzed at a concentration of 1.0% (m/v). the results showed that the more polar extracts (meoh-1 and meoh-2) have the highest inhibitory potential, although the hexane and ethyl acetate extract effects were important, especially for seed germination. comparatively, weed seed germination was more sensitive to the effects than plantlet development. mimosa pudica was more affected by the inhibitory effects of the extracts. however, for seed germination of senna obtusifolia, the extract meoh-1 showed 100% inhibition. the compounds ergosterol and ergosterol peroxide showed an inhibitory potential always below 35%, not showing the inhibitory potential of the hexane extract from which they were isolated. when these compounds were tested together, little increase was observed in the inhibitory activity.
Series-Connected Forward–Flyback Converter for High Step-Up Power Conver
International Journal of Engineering and Advanced Technology , 2012,
Abstract: Global energy consumption tends to grow continuously. To satisfy the demand for electric power against a background of the depletion of conventional, fossil resources the renewable energy sources are becoming more popular.According to the researches despite its fluctuating nature and weather dependency the capacity of renewable resources can satisfy overall global demand for energy. High gain DC/DC converters are the key part of renewable energy systems .The designing of high gain DC/DC converters is imposed by severe demands. The power conditioning systems for the photovoltaic power sources needs high step-up voltage gain due to the low output of the generating sources. This paper presents a high step-up topology employing a Series-connected Forward-FlyBack converter, which has a series-connected output for high boosting voltage-transfer gain. Series-connected Forward-FlyBack converter is a hybrid type of forward and flyback converter. By stacking the outputs of them extremely high voltage gain can be obtained with small volume and high efficiency with a galvanic isolation. The separated secondary windings reduce the voltage stress of the secondary rectifiers and results in high efficiency.
Avalia??o do efeito antifúngico do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)
Deus, R.J.A;Alves, C.N;Arruda, M.S.P;
Revista Brasileira de Plantas Medicinais , 2011, DOI: 10.1590/S1516-05722011000100001
Abstract: copaifera multijuga hayne oil in natura and its fractions were evaluated as to their fungitoxic activities against five filamentous fungus species belonging to the genus aspergillus and three yeast species of the genus candida. oleoresin and essential oil concentrations ranging from 0.08 mg ml-1 to 1.6 mg ml-1 were used for qualitative and quantitative analyses. the samples were placed onto 5mm-diameter paper discs distributed on sabouraud's medium in petri dishes inoculated with spores of the microorganisms and incubated at 28oc for 10 days. a solution containing 1.6 mg ml-1 miconazole nitrate was used as positive control. qualitative results showed that the oleoresin presented good activity, while a fraction of the essential oil was highly effective against candida parapsilosis ioc-2882, aspergillus flavus ioc-3874 and a tamarii ioc-187 with 16.0±1.4 mm, 19.5±2.1 mm and 12.5±3.5 mm inhibition halos, respectively. the quantitative evaluation showed that 0.3 mg ml-1 oleoresin inhibited the growth of aspergillus flavus and candida parapsilosis, while 0.08 mg ml-1 of the essential oil fraction reached this same activity.
Single Stage Inverter Topology for Renewable Resources
Jeena Mary Abraham,M.S.P.Subathra,Senraj.R
International Journal of Engineering and Advanced Technology , 2013,
Abstract: Power sector faces great troubles in the generation of power when the energy sources are renewable resources like wind power, hydro turbines etc. These resources may not be available at a constant rate continuously. Wind power generation is high only when the velocity of the wind is high, but this may not happen all the time. So the input will not be stable, in such situations inorder to produce a stable, stepped up ac voltage with high reliability, high boost gain and efficiency, the use of single stage boost inverter with coupled inductor is suggested.
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